Pollution characteristics of volatile organic compounds, polycyclic aromatic hydrocarbons and phthalate esters emitted from plastic wastes recycling granulation plants in Xingtan Town, South China

NASA Astrophysics Data System (ADS)

Huang, De-Yin; Zhou, Shun-Gui; Hong, Wei; Feng, Wei-Feng; Tao, Liang

2013-06-01

With the aim to investigate the main pollution characteristics of exhaust gases emitted from plastic waste recycling granulation plants, mainly volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs) were analyzed in Xingtan Town, the largest distribution center of plastic waste recycling in China. Both inside and outside the plants, the total concentrations of volatile monocyclic aromatic hydrocarbons (MAHs), PAHs and PAEs ranged from 2000 to 3000 μg m-3, 450 to 1200 ng m-3, and 200 to 1200 ng m-3, respectively. Their concentration levels inside the plants were higher than those outside the plants, and PAHs and PAEs were mainly distributed in the gas-phase. Notably, highly toxic benzo[a]pyrene (BaP) could be detected inside the plants, and harmful PAEs could be detected not only inside but also outside the plants, although PAEs are non-volatile. The exhaust gas composition and concentration were related to the plastic feedstock and granulation temperature.

Characterization of organic aromatic compounds in soils affected by an uncontrolled tire landfill fire through the use of comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

PubMed

Escobar-Arnanz, J; Mekni, S; Blanco, G; Eljarrat, E; Barceló, D; Ramos, L

2018-02-09

Discarded vehicle tires have become an increasing concern worldwide due to the enormous amount of wastes generated and the increasing evidence of health problems associated to their disposal and accidental combustion. Previous studies conducted involving either simulated or open uncontrolled tire fires have identified aromatics belonging to two main classes, volatile organic compounds and polycyclic aromatic compounds (PAHs), as the most relevant chemicals generated in these burning processes. As a consequence, and due to their recognized toxicity, most studies reported up to now have mainly focused on these two categories of compounds being information concerning the possible occurrence of other aromatic classes rather limited. In this study, the enhanced separation power and structural confirmation capabilities provided by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-ToF MS) has been used, for the first time, for the non-targeted analysis of soils impacted by a tire fire and an ash collected at the scene of the fire. In total, 118 volatile and semi-volatile aromatic compounds have been differentiated. Among them, 104 compounds have been either positively or tentatively identified. PAHs with 3-5 rings and their alkyl-derivatives were the most numerous and relevant classes in the investigated samples. A significant number of sulfur, oxygen- and nitrogen-containing PAHs were also detected in the samples. The application of a script function to the raw GC×GC-ToF MS data allowed the fast filtering and automatic recognition of compounds containing halogens in their structure. This part of the study evidenced that only a limited number of regulated persistent organic pollutants were present in the investigated samples. However, it also revealed the presence of emerging organophosphorous flame retardants, whose levels in tire fire impacted soils are reported for the first time. Copyright © 2017 Elsevier B.V. All rights reserved.

Global simulation of aromatic volatile organic compounds in the atmosphere

NASA Astrophysics Data System (ADS)

Cabrera Perez, David; Taraborrelli, Domenico; Pozzer, Andrea

2015-04-01

Among the large number of chemical compounds in the atmosphere, the organic group plays a key role in the tropospheric chemistry. Specifically the subgroup called aromatics is of great interest. Aromatics are the predominant trace gases in urban areas due to high emissions, primarily by vehicle exhausts and fuel evaporation. They are also present in areas where biofuel is used (i.e residential wood burning). Emissions of aromatic compounds are a substantial fraction of the total emissions of the volatile organic compounds (VOC). Impact of aromatics on human health is very important, as they do not only contribute to the ozone formation in the urban environment, but they are also highly toxic themselves, especially in the case of benzene which is able to trigger a range of illness under long exposure, and of nitro-phenols which cause detrimental for humans and vegetation even at very low concentrations. The aim of this work is to assess the atmospheric impacts of aromatic compounds on the global scale. The main goals are: lifetime and budget estimation, mixing ratios distribution, net effect on ozone production and OH loss for the most emitted aromatic compounds (benzene, toluene, xylenes, ethylbenzene, styrene and trimethylbenzenes). For this purpose, we use the numerical chemistry and climate simulation ECHAM/MESSy Atmospheric Chemistry (EMAC) model to build the global atmospheric budget for the most emitted and predominant aromatic compounds in the atmosphere. A set of emissions was prepared in order to include biomass burning, vegetation and anthropogenic sources of aromatics into the model. A chemical mechanism based on the Master Chemical Mechanism (MCM) was developed to describe the chemical oxidation in the gas phase of these aromatic compounds. MCM have been reduced in terms of number of chemical equation and species in order to make it affordable in a 3D model. Additionally other features have been added, for instance the production of HONO via ortho-nitrophenols photolysis. The model results are compared with observations from different surface and aircraft campaigns in order to estimate the accuracy of the model.

The effect of surfactant on headspace single drop microextraction for the determination of some volatile aroma compounds in citronella grass and lemongrass leaves by gas chromatography

USDA-ARS?s Scientific Manuscript database

A rapid method for the determination of some volatile aromatic compounds (VACs), including citronellal, citronellol, neral, geranial, geraniol, and eugenol in citronella grass and lemongrass leaves, was developed using surfactant as a surface tension modifier while performing headspace single drop m...

Structural changes in plastids of developing Splachnum ampullaceum sporophytes and relationship to odour production.

PubMed

McCuaig, B; Dufour, S C; Raguso, R A; Bhatt, A P; Marino, P

2015-03-01

Many mosses of the family Splachnaceae are entomophilous and rely on flies for spore dispersal. Splachnum ampullaceum produces a yellow- or pink-coloured hypophysis that releases volatile compounds, attracting flies to the mature moss. The biosynthetic sources of the visual and aromatic cues within the hypophysis have not been identified, and may be either symbiotic cyanobacteria or chromoplasts that break down lipids into volatile compounds. Here, we used transmission electron microscopy and gas chromatography-mass spectrometry (GC-MS) to investigate the sources of these attractants, focusing on different tissues and stages of maturation. Microscopy revealed an abundance of plastids within the hypophysis, while no symbiotic bacteria were observed. During plant maturation, plastids differentiated from amyloplasts with large starch granules to photosynthetic chloroplasts and finally to chromoplasts with lipid accumulations. We used GC-MS to identify over 50 volatile organic compounds from mature sporophytes including short-chain oxygenated compounds, unsaturated irregular terpenoids, fatty acid-derived 6- and 8-carbon alcohols and ketones, and the aromatic compounds acetophenone and p-cresol. The hypophysis showed localised production of pungent volatiles, mainly short-chain fermentation compounds and p-cresol. Some of these volatiles have been shown to be produced from lipid oxidase degradation of linolenic acid within chromoplasts. However, other compounds (such as cyclohexanecarboxylic acid esters) may have a microbial origin. Further investigation is necessary to identify the origin of fly attractants in these mosses. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Volatile flavor compounds in yogurt: a review.

PubMed

Cheng, Hefa

2010-11-01

Considerable knowledge has been accumulated on the volatile compounds contributing to the aroma and flavor of yogurt. This review outlines the production of the major flavor compounds in yogurt fermentation and the analysis techniques, both instrumental and sensory, for quantifying the volatile compounds in yogurt. The volatile compounds that have been identified in plain yogurt are summarized, with the few key aroma compounds described in detail. Most flavor compounds in yogurt are produced from lipolysis of milkfat and microbiological transformations of lactose and citrate. More than 100 volatiles, including carbonyl compounds, alcohols, acids, esters, hydrocarbons, aromatic compounds, sulfur-containing compounds, and heterocyclic compounds, are found in yogurt at low to trace concentrations. Besides lactic acid, acetaldehyde, diacetyl, acetoin, acetone, and 2-butanone contribute most to the typical aroma and flavor of yogurt. Extended storage of yogurt causes off-flavor development, which is mainly attributed to the production of undesired aldehydes and fatty acids during lipid oxidation. Further work on studying the volatile flavor compounds-matrix interactions, flavor release mechanisms, and the synergistic effect of flavor compounds, and on correlating the sensory properties of yogurt with the compositions of volatile flavor compounds are needed to fully elucidate yogurt aroma and flavor.

Effects of gasoline aromatic content on emissions of volatile organic compounds and aldehydes from a four-stroke motorcycle.

PubMed

Yao, Yung-Chen; Tsai, Jiun-Horng

2013-01-01

A new four-stroke carburettor motorcycle engine without any engine adjustments was used to study the impact of fuel aromatic content on the exhaust emissions of organic air pollutants (volatile organic compounds and carbonyls). Three levels of aromatic content, i.e. 15, 25, and 50% (vol.) aromatics mixed with gasoline were tested. The emissions of aromatic fuel were compared with those of commercial unleaded gasoline. The results indicated that the A 15 (15 vol% aromatics in gasoline) fuel exhibited the greatest total organic emission improvement among these three aromatic fuels as compared with commercial gasoline, reaching 59%. The highest emission factors of alkanes, alkenes, and carbonyl groups appeared in the reference fuel (RF) among all of the test fuels. A 15 showed the highest emission reduction in alkanes (73%), aromatics (36%), and carbonyls (28%), as compared to those of the RF. The highest emission reduction ofalkenes was observed when using A25 as fuel. A reduction in fuel aromatic content from 50 to 25 and 15 vol% in gasoline decreased benzene and toluene emissions, but increased the aldehyde emissions. In general, the results showed that the highest emission reductions for the most of measured organic pollutants appeared when using A 15 as the fuel.

Emission of Volatile Compounds from Apple Plants Infested with Pandemis heparana Larvae, Antennal Response of Conspecific Adults, and Preliminary Field Trial.

PubMed

Giacomuzzi, Valentino; Cappellin, Luca; Khomenko, Iuliia; Biasioli, Franco; Schütz, Stefan; Tasin, Marco; Knight, Alan L; Angeli, Sergio

2016-12-01

This study investigated the volatile emission from apple (Malus x domestica Borkh., cv. Golden Delicious) foliage that was either intact, mechanically-damaged, or exposed to larval feeding by Pandemis heparana (Denis and Schiffermüller) (Lepidoptera: Tortricidae). Volatiles were collected by closed-loop-stripping-analysis and characterized by gas chromatography-mass spectrometry in three time periods: after 1 h and again 24 and 48 h later. Volatiles for all treatments also were monitored continuously over a 72-h period by the use of proton transfer reaction - time of flight-mass spectrometry (PTR-ToF-MS). In addition, the volatile samples were analyzed by gas chromatography-electroantennographic detection (GC-EAD) using male and female antennae of P. heparana. Twelve compounds were detected from intact foliage compared with 23 from mechanically-damaged, and 30 from P. heparana-infested foliage. Interestingly, six compounds were released only by P. heparana-infested foliage. The emission dynamics of many compounds measured by PTR-ToF-MS showed striking differences according to the timing of herbivory and the circadian cycle. For example, the emission of green leaf volatiles began shortly after the start of herbivory, and increased over time independently from the light-dark cycle. Conversely, the emission of terpenes and aromatic compounds showed a several-hour delay in response to herbivory, and followed a diurnal rhythm. Methanol was the only identified volatile showing a nocturnal rhythm. Consistent GC-EAD responses were found for sixteen compounds, including five aromatic ones. A field trial in Sweden demonstrated that benzyl alcohol, 2-phenylethanol, phenylacetonitrile, and indole lures placed in traps were not attractive to Pandemis spp. adults, but 2-phenylethanol and phenylacetonitrile when used in combination with acetic acid were attractive to both sexes.

Gondola-shaped tetra-rhenium metallacycles modified evanescent wave infrared chemical sensors for selective determination of volatile organic compounds.

PubMed

Huang, Genin Gary; Lee, Chung-Jay; Tsai, Bo-Chan; Yang, Jyisy; Sathiyendiran, Malaichamy; Lu, Kuang-Lieh

2011-07-15

Water-stable and cavity-contained rhenium metallacycles were synthesized, and their ability to selectively interact with volatile organic compounds (VOCs) systematically studied using attenuated total reflection infrared (ATR-IR) spectroscopy. Integrating the unique properties of rhenium metallacycles into optical sensing technologies significantly improves selectivity in detecting aromatic compounds. To explore the interaction of rhenium metallacycles with VOCs, the surface of ATR sensing elements was modified with the synthesized rhenium metallacycles and used to detect VOCs. The results indicate that rhenium metallacycles have crown ether-like recognition sites, which can selectively interact with aromatic compounds, especially those bearing polar functional groups. The IR absorption bands of rhenium metallacycles shift significantly upon adsorption of aromatic VOCs, revealing a strong interaction between the tetra-rhenium metallacycles and guest aromatic compounds. Optimizing the thickness of the metallacycles coated on the surface of the sensing element led to rapid response in detection. The dynamic range of response was generally up to 30 mg/L with detection limits ca. 30 μg/L. Further studies of the effect of interferences indicate that recovery can be higher than 95% for most of the compounds tested. The results on the flow-cell device indicated that the performances were similar to a static detection system but the detection of VOCs can be largely simplified. Copyright © 2011 Elsevier B.V. All rights reserved.

Volatile compounds of dry beans (Phaseolus vulgaris L.).

PubMed

Oomah, B Dave; Liang, Lisa S Y; Balasubramanian, Parthiba

2007-12-01

Volatile compounds of uncooked dry bean (Phaseolus vulgaris L.) cultivars representing three market classes (black, dark red kidney and pinto) grown in 2005 were isolated with headspace solid phase microextraction (HS-SPME), and analyzed with gas chromatography mass spectrometry (GC-MS). A total of 62 volatiles consisting of aromatic hydrocarbons, aldehydes, alkanes, alcohols and ketones represented on average 62, 38, 21, 12, and 9 x 10(6) total area counts, respectively. Bean cultivars differed in abundance and profile of volatiles. The combination of 18 compounds comprising a common profile explained 79% of the variance among cultivars based on principal component analysis (PCA). The SPME technique proved to be a rapid and effective method for routine evaluation of dry bean volatile profile.

Aromatic volatile organic compounds and their role in ground-level ozone formation in Russia

NASA Astrophysics Data System (ADS)

Berezina, E. V.; Moiseenko, K. B.; Skorokhod, A. I.; Elansky, N. F.; Belikov, I. B.

2017-05-01

This paper reports proton mass spectrometry data on aromatic volatile organic compounds (VOCs) (benzene, toluene, phenol, styrene, xylene, and propylbenzene) obtained in different Russian regions along the Trans-Siberian Railway from Moscow to Vladivostok, based on expedition data retrieved using the TRO-ICA-12 mobile laboratory in the summer of 2008. The contribution of aromatic VOCs to ozone formation in the cities and regions along the measurement route has been estimated quantitatively. The greatest contribution of aromatic VOCs to ozone formation is characteristic of large cities along the Trans-Siberian Railway (up to 7.5 ppbv O3) specified by the highest concentrations of aromatic VOCs (1-1.7 ppbv) and nitrogen oxides (>20 ppbv). The results obtained are indicative of a considerable contribution (30-50%) of anthropogenic emissions of VOCs to photochemical ozone generation in the large cities along the Trans-Siberian Railway in hot and dry weather against the background of a powerful natural factor such as isoprene emissions controlling the regional balance of ground-level ozone in warm seasons.

Oxidative decomposition of aromatic hydrocarbons by electron beam irradiation

NASA Astrophysics Data System (ADS)

Han, Do-Hung; Stuchinskaya, Tatiana; Won, Yang-Soo; Park, Wan-Sik; Lim, Jae-Kyong

2003-05-01

Decomposition of aromatic volatile organic compounds (VOCs) under electron beam irradiation was studied in order to examine the kinetics of the process, to characterize the reaction product distribution and to develop a process of waste gas control technology. Toluene, ethylbenzene, o-, m-, p-xylenes and chlorobenzene were used as target materials. The experiments were carried out at doses ranging from 0.5 to 10 kGy, using a flow reactor utilized under electron beam irradiation. Maximum degrees of decomposition carried out at 10 kGy in air environment were 55-65% for “non-chlorinated” aromatic VOC and 85% for chlorobenzene. It was found that a combination of aromatic pollutants with chlorobenzene would considerably increase the degradation value up to nearly 50% compared to the same compounds in the absence of chlorine groups. Based on our experimental observation, the degradation mechanism of the aromatic compounds combined with chloro-compound suggests that a chlorine radical, formed from EB irradiation, induces a chain reaction, resulting in an accelerating oxidative destruction of aromatic VOCs.

Gas Chromatography-Mass Spectrometry-Olfactometry To Control the Aroma Fingerprint of Extra Virgin Olive Oil from Three Tunisian Cultivars at Three Harvest Times.

PubMed

Ben Brahim, Samia; Amanpour, Asghar; Chtourou, Fatma; Kelebek, Hasim; Selli, Serkan; Bouaziz, Mohamed

2018-03-21

Gas chromatography-mass spectrometry-olfactometry was used for the analysis of volatile compounds and key odorants of three less studied Tunisian olive oil cultivars for the first time. A total of 42 aroma compounds were identified and quantified in extra virgin olive oils. The present study revealed that the most dominant volatiles in olive oil samples qualitatively and quantitatively were aldehydes and alcohols, followed by terpenes and esters. Indeed, chemometric analysis has shown a correlation between chemical compounds and sensory properties. The determination of aroma-active compounds of olive oil samples was carried out using aroma extract dilution analysis. A total of 15 aroma-active compounds were detected in the aromatic extract of extra virgin olive oil, of which 14 were identified. On the basis of the flavor dilution (FD) factor, the most potent aromatic active compound was hexanal (FD = 512) in Fakhari olive oil, (FD = 256) in Touffehi oils, and (FD = 128) in Jemri olive oil.

Italian and Spanish commercial tomato sauces for pasta dressing: study of sensory and head-space profiles by Flash Profiling and solid-phase microextraction-gas chomatography-mass spectrometry.

PubMed

Bendini, Alessandra; Vallverdú-Queralt, Anna; Valli, Enrico; Palagano, Rosa; Lamuela-Raventos, Rosa Maria; Toschi, Tullia Gallina

2017-08-01

The sensory and head-space profiles of Italian and Spanish commercial tomato sauces were investigated. The Flash Profiling method was used to evaluate sensory characteristics. Samples within each set were ranked according to selected descriptors. One hundred volatile compounds were identified by solid-phase microextraction-gas chomatography-mass spectrometry. For Italian samples, the sensory notes of basil/aromatic herbs, acid and cooked tomato were among those perceived most by the assessors, whereas, in Spanish samples, the sensory attributes of garlic/onion and onion/sweet pepper and, in Italian samples, cooked tomato were among those found most frequently. Data were elaborated using multivariate statistical approaches and interesting correlations were observed among the different sensory attributes and related volatile compounds. Spanish samples were characterized by the highest content of volatiles linked to the thermal treatment of tomatoes and to raw and sautéed garlic and onion, whereas the Italian samples were characterized by terpenic compounds typical of basil and volatile molecules derived from fresh tomato. These results confirm the influence of both formulation and production processes on the aromatic profile (sensory attributes and volatile compounds) of tomato products, which is probably related to the different eating habits and culinary traditions in Italy and Spain. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

PTR-MS Characterization of VOCs Associated with Commercial Aromatic Bakery Yeasts of Wine and Beer Origin.

PubMed

Capozzi, Vittorio; Makhoul, Salim; Aprea, Eugenio; Romano, Andrea; Cappellin, Luca; Sanchez Jimena, Ana; Spano, Giuseppe; Gasperi, Flavia; Scampicchio, Matteo; Biasioli, Franco

2016-04-12

In light of the increasing attention towards "green" solutions to improve food quality, the use of aromatic-enhancing microorganisms offers the advantage to be a natural and sustainable solution that did not negatively influence the list of ingredients. In this study, we characterize, for the first time, volatile organic compounds (VOCs) associated with aromatic bakery yeasts. Three commercial bakery starter cultures, respectively formulated with three Saccharomyces cerevisiae strains, isolated from white wine, red wine, and beer, were monitored by a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), a direct injection analytical technique for detecting volatile organic compounds with high sensitivity (VOCs). Two ethanol-related peaks (m/z 65.059 and 75.080) described qualitative differences in fermentative performances. The release of compounds associated to the peaks at m/z 89.059, m/z 103.075, and m/z 117.093, tentatively identified as acetoin and esters, are coherent with claimed flavor properties of the investigated strains. We propose these mass peaks and their related fragments as biomarkers to optimize the aromatic performances of commercial preparations and for the rapid massive screening of yeast collections.

Identification of volatiles in leaves of Alpinia zerumbet 'Variegata' using headspace solid-phase microextraction-gas chromatography-mass spectrometry.

PubMed

Chen, Jian Yan; Ye, Zheng Mei; Huang, Tian Yi; Chen, Xiao Dan; Li, Yong Yu; Wu, Shao Hua

2014-07-01

Alpinia zerumbet 'Variegata' is an aromatic medicinal plant, its foliage producing an intense, unique fragrant odor. This study identified 46 volatile compounds in the leaf tissue of this plant using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The major compounds included 1, 8-cineole (43.5%), p-cymene (14.7%), humulene (5.5%), camphor (5.3%), linalool (4.7%), (E)-methyl cinnamate (3.8%), gamma-cadinene (3.3%), humulene oxide II (2.1%) and a-terpineol (1.5%). The majority of the volatiles were terpenoids of which oxygenated monoterpenes were the most abundant, accounting for 57.2% of the total volatiles. Alcohols made up the largest (52.8%) and aldehydes the smallest (0.2%) portions of the volatiles. Many bioactive compounds were present in the volatiles.

Volatiles from the xylarialean fungus Hypoxylon invadens.

PubMed

Dickschat, Jeroen S; Wang, Tao; Stadler, Marc

2018-01-01

The volatiles emitted by agar plate cultures of the xylarialean fungus Hypoxylon invadens were investigated by use of a closed loop stripping apparatus in combination with GC-MS. Several aromatic compounds were found that could only be identified by comparison to all possible constitutional isomers with different ring substitution patterns. For the set of identified compounds a plausible biosynthetic scheme was suggested that gives further support for the assigned structures.

Increase in volatilization of organic compounds using air sparging through addition in alcohol in a soil-water system.

PubMed

Chao, Huan-Ping; Hsieh, Lin-Han Chiang; Tran, Hai Nguyen

2018-02-15

This study developed a novel method to promote the remediation efficiency of air sparging. According to the enhanced-volatilization theory presented in this study, selected alcohols added to groundwater can highly enhance the volatilization amounts of organic compounds with high Henry's law constants. In this study, the target organic compounds consisted of n-hexane, n-heptane, benzene, toluene, 1,1,2-trichloroethane, and tetrachloroethene. n-pentanol, n-hexanol, and n-heptanol were used to examine the changes in the volatilization amounts of organic compounds in the given period. Two types of soils with high and low organic matter were applied to evaluate the transport of organic compounds in the soil-water system. The volatilization amounts of the organic compounds increased with increasing alcohol concentrations. The volatilization amounts of the test organic compounds exhibited a decreasing order: n-heptanol>n-hexanol>n-pentanol. When 10mg/L n-heptanol was added to the system, the maximum volatilization enhancement rate was 18-fold higher than that in distilled water. Samples of soil with high organic matter might reduce the volatilization amounts by a factor of 5-10. In the present study, the optimal removal efficiency for aromatic compounds was approximately 98%. Copyright © 2017 Elsevier B.V. All rights reserved.

[Composition of the electrocautery smoke: integrative literature review].

PubMed

Tramontini, Cibele Cristina; Galvão, Cristina Maria; Claudio, Caroline Vieira; Ribeiro, Renata Perfeito; Martins, Júlia Trevisan

2016-02-01

To identify the composition of the smoke produced by electrocautery use during surgery. Integrative review with search for primary studies conducted in the databases of the US National Library of Medicine National Institutes of Health, Cumulative Index to Nursing and Allied Health Literature, and Latin American and Caribbean Health Sciences, covering the studies published between 2004 and 2014. The final sample consisted of 14 studies grouped into three categories, namely; polycyclic aromatic hydrocarbons, volatile compounds and volatile organic compounds. There is scientific evidence that electrocautery smoke has volatile toxic, carcinogenic and mutagenic compounds, and its inhalation constitutes a potential chemical risk to the health of workers involved in surgeries.

Influence of Tunisian aromatic plants on the prevention of oxidation in soybean oil under heating and frying conditions.

PubMed

Saoudi, Salma; Chammem, Nadia; Sifaoui, Ines; Bouassida-Beji, Maha; Jiménez, Ignacio A; Bazzocchi, Isabel L; Silva, Sandra Diniz; Hamdi, Moktar; Bronze, Maria Rosário

2016-12-01

The aim of this study was to improve the oxidative stability of soybean oil by using aromatic plants. Soybean oil flavored with rosemary (ROS) and soybean oil flavored with thyme (THY) were subjected to heating for 24h at 180°C. The samples were analyzed every 6h for their total polar compounds, anisidine values, oxidative stability and polyphenols content. The tocopherols content was determined and volatile compounds were also analyzed. After 24h of heating, the incorporation of these plants using a maceration process reduced the polar compounds by 69% and 71% respectively, in ROS and THY compared to the control. Until 6h of heating, the ROS kept the greatest oxidative stability. The use of the two extracts preserves approximately 50% of the total tocopherols content until 18h for the rosemary and 24h for the thyme flavored oils. Volatile compounds known for their antioxidant activity were also detected in the formulated oils. Aromatic plants added to the soybean oil improved the overall acceptability of potato crisps (p<0.05) until the fifteenth frying. Copyright © 2016 Elsevier Ltd. All rights reserved.

Global volatile profile of virgin olive oils flavoured by aromatic/medicinal plants.

PubMed

Perestrelo, R; Silva, C; Silva, P; Câmara, J S

2017-07-15

The global volatile profile of commercial virgin olive oils and flavoured olive oils with aromatic/medicinal plants, was established using liquid-liquid microextraction (LLME) and headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-qMS). More than 60 volatile organic compounds (VOCs belonging to different groups were identified using both methods. Olive oils volatile profile was slightly influenced by maceration process, which occurred at room temperature (20±2°C) for 15days. The predominant differences were observed in terpenoids group, since some of them were only identified in the flavoured olive oils, while others showed an increase with the maceration process. VOCs mass transfer from plants to olive oils could explain the observed results. Principal components analysis (PCA) applied to LLME/GC-qMS data allowed to distinguish the olive oils. The flavoured oils would increase the use of olive oil among consumers as consequence of the improvement of its aromatic profile and healthy properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

ENHANCED CONCENTRATION AND ANALYSIS METHOD FOR MEASURING WATER SOLUABLE ENDOGENOUS COMPOUNDS IN HUMAN BREATH

EPA Science Inventory

Exhaled human breath analysis has become a standard technique for assessing exposure to exogenous volatile organic compounds (VOCs) such as trihalomethanes from water chlorination; aromatics, hydrocarbons, and oxygenates from fuels usage; and various chlorinated solvents from i...

Impact of yeast starter formulations on the production of volatile compounds during wine fermentation.

PubMed

Romano, Patrizia; Pietrafesa, Rocchina; Romaniello, Rossana; Zambuto, Marianna; Calabretti, Antonella; Capece, Angela

2015-01-01

The most diffused starter formulation in winemaking is actually represented by active dry yeast (ADY). Spray-drying has been reported as an appropriate preservation method for yeast and other micro-organisms. Despite the numerous advantages of this method, the high air temperatures used can negatively affect cell viability and the fermentative performance of dried cells. In the present study, 11 wine S. cerevisiae strains (both indigenous and commercial) were submitted to spray-drying; different process conditions were tested in order to select the conditions allowing the highest strain survival. The strains exhibited high variability for tolerance to spray-drying treatment. Selected strains were tested in fermentation at laboratory scale in different formulations (free fresh cells, free dried cells, immobilized fresh cells and immobilized dried cells), in order to assess the influence of starter formulation on fermentative fitness of strains and aromatic quality of wine. The analysis of volatile fraction in the experimental wines produced by selected strains in different formulations allowed identification of > 50 aromatic compounds (alcohols, esters, ketones, aldehydes and terpenes). The results obtained showed that the starter formulation significantly influenced the content of volatile compounds. In particular, the wines obtained by strains in dried forms (as both free and immobilized cells) contained higher numbers of volatile compounds than wines obtained from fresh cells. Copyright © 2014 John Wiley & Sons, Ltd.

Volatile Composition of Essential Oils from Different Aromatic Herbs Grown in Mediterranean Regions of Spain

PubMed Central

El-Zaeddi, Hussein; Martínez-Tomé, Juan; Calín-Sánchez, Ángel; Burló, Francisco; Carbonell-Barrachina, Ángel A.

2016-01-01

Volatile composition of essential oils from dill, parsley, coriander, and mint were investigated at different harvest dates to determine the most suitable harvest time for each these herbs. Hydrodistillation (HD), using a Deryng system, was used for isolating the essential oils. Isolation and identification of the volatile compounds were performed using gas chromatography-mass spectrometry (GC-MS) instrument. The results of gas chromatography-flame ionization detector (GC-FID) analysis (quantification) showed that the main components in the essential oil of dill shoots were α-phellandrene, dill ether, and β-phellandrene, and the optimal harvest date was D2 (second harvest, fourth week of February 2015). For parsley shoots, the main compounds were 1,3,8-p-menthatriene, β-phellandrene, and P1 (first harvest, third week of November 2014) was the sample with the highest essential oil. For coriander, the main compounds were E-2-dodecenal, dodecanal, and octane and the highest contents were found at C2 (second harvest, 5 February 2015); while, the main two components of mint essential oil were carvone and limonene, and the highest contents were found at M1 (first harvest, second week of December 2014). The present study was the first one reporting data on descriptive sensory analysis of aromatic herbs at this optimal harvest date according to the content of volatile compounds of their essential oils. PMID:28231136

Impact of gas chromatography and mass spectrometry combined with gas chromatography and olfactometry for the sex differentiation of Baccharis articulata by the analysis of volatile compounds.

PubMed

Minteguiaga, Manuel; Umpiérrez, Noelia; Fariña, Laura; Falcão, Manuel A; Xavier, Vanessa B; Cassel, Eduardo; Dellacassa, Eduardo

2015-09-01

The Baccharis genus has more than 400 species of aromatic plants. However, only approximately 50 species have been studied in oil composition to date. From these studies, very few take into consideration differences between male and female plants, which is a significant and distinctive factor in Baccharis in the Asteraceae family. Baccharis articulata is a common shrub that grows wild in south Brazil, northern and central Argentina, Bolivia, Paraguay and Uruguay. It is considered to be a medicinal plant and is employed in traditional medicine. We report B. articulata male and female volatile composition obtained by simultaneous distillation-extraction technique and analyzed by gas chromatography with mass spectrometry. Also, an assessment of aromatic differences between volatile extracts was evaluated by gas chromatography with olfactometry. The results show a very similar chemical composition between male and female extracts, with a high proportion of terpene compounds of which β-pinene, limonene and germacrene D are the main components. Despite the chemical similarity, great differences in aromatic profile were found: male plant samples exhibited the strongest odorants in number and intensity of aromatic attributes. These differences explain field observations which indicate differences between male and female flower aroma, and might be of ecological significance in the attraction of pollinating insects. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

δ 13C of free and macromolecular aromatic structures in the murchison meteorite

NASA Astrophysics Data System (ADS)

Sephton, M. A.; Pillinger, C. T.; Gilmour, I.

1998-05-01

Analyses of the organic compounds in the Murchison meteorite have led to a greater understanding of the nature of extraterrestrial organic materials. However, the relationship between low and high molecular weight material remains poorly understood. To investigate this relationship, untreated Murchison was subjected to supercritical fluid extraction (SFE) to obtain the free organic components in the meteorite. Toluene and other volatile aromatic hydrocarbons dominated the extract, and the carbon isotopic composition of these molecules was determined by gas chromatography-isotope ratio-mass spectrometry (GCIRMS). δ 13C values of the aromatic hydrocarbons ranged from -28.8 to -5.8‰. These compounds displayed a 13C-enrichment with increasing carbon number suggesting an origin by cracking. The high molecular weight organic material in the meteorite was isolated and subjected to hydrous pyrolysis. This procedure produced a number of aromatic products, the majority of which were volatile aromatic hydrocarbons, particularly toluene. SFE was used to extract and successfully retain them. This enabled the first carbon isotopic analysis of this poorly understood material to be performed at the molecular level by GCIRMS. δ 13C values for aromatic pyrolysis products occupied a range from -24.6 to -5.6‰. The trend of 13C-enrichment with increasing carbon number, observed in the free compounds, was also evident in the macromolecular fragments. Furthermore, the organic fragments of the macromolecular material were consistently 13C-enriched when compared to structurally identical free molecules. This suggested that the free aromatic hydrocarbons in Murchison were produced by the preterrestrial degradation of the organic macromolecular material. This natural degradation event was extended by the hydrous pyrolysis experiment.

Public health assessment for Pasley Solvents and Chemicals Inc. , Garden City, Nassau County, New York, Region 2. Cerclis No. NYD991292004. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1994-08-22

The Pasley Solvents and Chemicals site, which is on the National Priorities List, is situated between the borders of the Village of Garden City and Uniondale in the Town of Hempstead, Nassau County, New York. Soils at the site are contaminated with volatile organic compounds (VOCs), primarily solvent constituents and petroleum hydrocarbons compounds; semi-volatile compounds (primarily polycyclic aromatic hydrocarbon compounds); and several metals. Groundwater in the shallow and deep aquifers under the site is contaminated with VOCs, primarily solvent constituents and petroleum hydrocarbons compounds, and two semi-volatile compounds at the concentrations exceeding public health assessment comparison values. Limited information ismore » available on soil gas intrusion and indoor air contamination, and this pathway is of concern since occupied buildings are nearby and above contaminated groundwater plumes.« less

Volatile and semivolatile organic compounds in laboratory ...

EPA Pesticide Factsheets

Speciated volatile organic compounds (VOCs) and organic fine particulate matter (PM2.5) mass emission factors were determined from laboratory peat fire experiments. Peat samples originated from two wildlife reserves located near the coast of North Carolina, U.S. Gas and particulate organics were quantified by gas chromatography/mass spectrometry and by high pressure liquid chromatography. Hazardous air pollutants (HAPs) accounted for a large fraction (~60 %) of the speciated VOC emissions from peat burning, including large contributions of acetaldehyde, formaldehyde, benzene, toluene, and chloromethane. Speciated organic PM2.5 mass was dominated by the following compound classes: organic acids, levoglucosan, n-alkanes, and n-alkenes. Emission factors for PM2.5 organic acids including n-alkanoic acids, n-alkenoic acids, n-alkanedioic acids, and aromatic acids were reported for the first time for peat burning, representing the largest fraction of organic carbon (OC) mass (11-12 %) of all speciated compound classes measured in this work. Levoglucosan contributed 2-3 % of the OC mass, while methoxyphenols represented 0.2-0.3 % of the OC mass on a carbon mass basis. Retene was the most abundant particulate phase polycyclic aromatic hydrocarbon. Total HAP VOC and particulate polycyclic aromatic hydrocarbon emissions from a 2008 peat wildfire in North Carolina were estimated, suggesting that peat fires can contribute a large fraction of state-wide HAP emissions. This p

Ground-water contamination at an inactive coal and oil gasification plant site, Gas Works Park, Seattle, Washington

USGS Publications Warehouse

Turney, G.L.; Goerlitz, D.F.

1989-01-01

Gas Works Park, in Seattle, Washington, is located on the site of a coal and oil gasification plant that ceased operation in 1956. During operation, many types of wastes, including coal, tar, and oil, accumulated on site. The park soil is presently (1986) contaminated with compounds such as polynuclear aromatic hydrocarbons, volatile organic compounds, trace metals, and cyanide. Analyses of water samples from a network of observation wells in the park indicate that these compounds are also present in the groundwater. Polynuclear aromatic hydrocarbons and volatile organic compounds were identified in groundwater samples in concentrations as large as 200 mg/L. Concentrations of organic compounds were largest where groundwater was in contact with a nonaqueous phase liquid in the soil. Concentrations in groundwater were much smaller where no nonaqueous phase liquid was present, even if the groundwater was in contact with contaminated soils. This condition is attributed to weathering processes at the site, such as dissolution, volatilization, and biodegradation. Soluble, volatile, low-molecular-weight organic compounds are preferentially dissolved from the nonaqueous phase liquid into the groundwater. Where no nonaqueous phase liquid is present, only stained soils containing relatively insoluble, high-molecular-weight compounds remain; therefore, contaminant concentrations in the groundwater are much smaller. Concentrations of organic contaminants in the soils may still remain large. Values of specific conductance were as large as 5,280 microsiemens/cm, well above a background of 242 microsiemens/cm, suggesting large concentrations of minerals in the groundwater. Trace metal concentrations, however , were generally < 0.010 mg/L, and below limits of US EPA drinking water standards. Cyanide was present in groundwater samples from throughout the park, ranging in concentration from 0.01 to 8.6 mg/L. (Author 's abstract)

Extraction and GC determination of volatile aroma compounds from extracts of three plant species of the Apiaceae family

NASA Astrophysics Data System (ADS)

Stan, M.; Soran, M. L.; Varodi, C.; Lung, I.; Copolovici, L.; MǎruÅ£oiu, C.

2013-11-01

Parsley (Petroselinum crispum), dill (Anethum graveolens) and celery (Apium graveolens), three aromatic plants belonging to the Apiaceae (Umbelliferae) botanical family, were selected as sources of essential or volatile oils. Essential oils are composed of a large diversity of volatile aroma compounds. Plant-derived essential oils and extracts have long been used as natural agents in food preservation, pharmaceuticals and medicinal therapies. In the present study, the plant extracts from leaves of parsley, dill and celery, were obtained by maceration, ultrasound-assisted extraction and microwave-assisted extraction. All extractions were performed at 30°C, using different solvents (ethanol, diethyl ether, n-hexane) and solvent mixtures (1:1, v/v). The most effective solvent system for the extraction of volatile aroma compounds was diethyl ether - n-hexane (1:1, v/v). Extraction efficiency and determination of aroma volatiles were performed by GC-FID and GC-MS, respectively. The major volatile compounds present in plant extracts were myristicin, α-phellandrene, β-phellandrene, 1,3,8-p-menthatriene, apiol, dill ether and allyl phenoxyacetate.

Volatile and semivolatile organic compounds in laboratory peat fire emissions

NASA Astrophysics Data System (ADS)

George, Ingrid J.; Black, Robert R.; Geron, Chris D.; Aurell, Johanna; Hays, Michael D.; Preston, William T.; Gullett, Brian K.

2016-05-01

In this study, volatile and semi-volatile organic compound (VOCs and SVOCs) mass emission factors were determined from laboratory peat fire experiments. The peat samples originated from two National Wildlife Refuges on the coastal plain of North Carolina, U.S.A. Gas- and particle-phase organic compounds were quantified by gas chromatography-mass spectrometry and by high pressure liquid chromatography. Hazardous air pollutants (HAPs) accounted for a large fraction (∼60%) of the speciated VOC emissions from peat burning, including large contributions of acetaldehyde, formaldehyde, benzene, toluene, and chloromethane. In the fine particle mass (PM2.5), the following organic compound classes were dominant: organic acids, levoglucosan, n-alkanes, and n-alkenes. Emission factors for the organic acids in PM2.5 including n-alkanoic acids, n-alkenoic acids, n-alkanedioic acids, and aromatic acids were reported for the first time for peat burning, representing the largest fraction of organic carbon (OC) mass (11-12%) of all speciated compound classes measured in this work. Levoglucosan contributed to 2-3% of the OC mass, while methoxyphenols represented 0.2-0.3% of the OC mass on a carbon mass basis. Retene was the most abundant particulate phase polycyclic aromatic hydrocarbon (PAH). Total HAP VOC and particulate PAH emissions from a 2008 peat wildfire in North Carolina were estimated, suggesting that peat fires can contribute a large fraction of state-wide HAP emissions.

Relationship between sensory attributes and volatile compounds of polish dry-cured loin

PubMed Central

Górska, Ewa; Nowicka, Katarzyna; Jaworska, Danuta; Przybylski, Wiesław; Tambor, Krzysztof

2017-01-01

Objective The aim of this work was to determine the relationship between objective sensory descriptors and volatile flavour compound composition of Polish traditional dry-cured loin. Methods The volatile compounds were investigated by using solid phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS). For sensory assessment, the quantitative descriptive analysis (QDA) method was used. Results A total of 50 volatile compounds were found and assigned to 17 chemical families. Most of the detected volatile compounds derived from smoking, lipid oxidative reactions and seasoning (46.8%, 21.7%, and 18.9%, respectively). The dominant compounds were: aromatic hydrocarbon (toluene); alkanes (hexane, heptane, and 2,2,4-trimethylpentane); aldehyde (hexanal); alcohol (2-furanmethanol); ketone (3-hydroxy-2-butanone); phenol (guaiacol); and terpenes (eucalyptol, cymene, γ-terpinen, and limonene). Correlation analysis showed that some compounds derived from smoking were positively correlated with the intensity of cured meat odour and flavour and negatively with the intensity of dried meat odour and flavour, while terpenes were strongly correlated with odour and flavour of added spices. Conclusion The analysed dry-cured loins were characterized by specific and unique sensory profile. Odour and flavour of studied loins was mainly determined by volatile compounds originating from smoking, seasoning and lipid oxidation. Obtained results suggest that smoking process is a crucial stage during Polish traditional dry-cured loins production. PMID:27456422

[Component and content changes of volatiles from Chinese cabbage damaged by Plutella xylostella].

PubMed

Yang, Guang; You, Minsheng; Wei, Hui

2004-11-01

The study showed that Chinese cabbage, Brassica campestris could release a variety of volatiles, especially when infested by Plutella xylostella larvae. Among these volatiles, saturated hydrocarbon was dominant, aromatic hydrocarbon was the second, and unsaturated hydrocarbon, aldehyde, alcohol, ketone, acid and heteroaromatic compounds were existed with a small amount. Chinese cabbage damaged by Plutella xylostella larvae produced 3 times of volatiles in amount with more species than the control. The volatiles from control plants were mostly of small molecular weight, and those from Chinese cabbage damaged by Plutella xylostella were mostly of high molecular weight.

Mycotoxicogenic fungal inhibition by innovative cheese cover with aromatic plants.

PubMed

Moro, Armando; Librán, Celia M; Berruga, M Isabel; Zalacain, Amaya; Carmona, Manuel

2013-03-30

The use of aromatic plants and their extracts with antimicrobial properties may be compromised in the case of cheese, as some type of fungal starter is needed during its production. Penicillium verrucosum is considered a common cheese spoiler. The aim of this study was to evaluate the innovative use of certain aromatic plants as natural cheese covers in order to prevent mycotoxicogenic fungal growth (P. verrucosum). A collection of 12 essential oils (EOs) was obtained from various aromatic plants by solvent-free microwave extraction technology, and volatile characterisation of the EOs was carried out by gas chromatography/mass spectrometry. The most effective EOs against P. verrucosum were obtained from Anethum graveolens, Hyssopus officinalis and Chamaemelum nobile, yielding 50% inhibition of fungal growth at concentration values lower than 0.02 µL mL⁻¹. All EOs showed high volatile heterogeneity, with α-phellandrene, pinocamphone, isopinocamphone, α-pinene, camphene, 1,8-cineole, carvacrol and trans-anethole being found to be statistically significant in the antifungal model. The use of these aromatic plants as natural covers on cheese can satisfactorily inhibit the growth of some mycotoxicogenic fungal spoilers. Among the volatile compounds present, α- and β-phellandrene were confirmed as the most relevant in the inhibition. © 2012 Society of Chemical Industry.

Concentrations and co-occurrence correlations of 88 volatile organic compounds (VOCs) in the ambient air of 13 semi-rural to urban locations in the United States

USGS Publications Warehouse

Pankow, J.F.; Luo, W.; Bender, D.A.; Isabelle, L.M.; Hollingsworth, J.S.; Chen, C.; Asher, W.E.; Zogorski, J.S.

2003-01-01

The ambient air concentrations of 88 volatile organic compounds were determined in samples taken at 13 semi-rural to urban locations in Maine, Massachusetts, New Jersey, Pennsylvania, Ohio, Illinois, Louisiana, and California. The sampling periods ranged from 7 to 29 months, yielding a large data set with a total of 23,191 individual air concentration values, some of which were designated "ND" (not detected). For each compound at each sampling site, the air concentrations (ca, ppbV) are reported in terms of means, medians, and means of the detected values. The analytical method utilized adsorption/thermal desorption with air-sampling cartridges. The analytes included numerous halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. At some sites, the air concentrations of the gasoline-related aromatic compounds and the gasoline additive methyl tert-butyl ether were seasonally dependent, with concentrations that maximized in the winter. For each site studied here, the concentrations of some compounds were highly correlated one with another (e.g., the BTEX group (benzene, toluene, ethylbenzene, and the xylenes). Other aromatic compounds were also all generally correlated with one another, while the concentrations of other compound pairs were not correlated (e.g., benzene was not correlated with CFC-12). The concentrations found for the BTEX group were generally lower than the values that have been previously reported for urbanized and industrialized areas of other nations. ?? 2003 Elsevier Ltd. All rights reserved.

The effect of deodorization on volatile compositions of fucoidan extracted from brown seaweed (Sargassum sp.)

NASA Astrophysics Data System (ADS)

Khalafu, Sharifah Habibah Syed; Mustapha, Wan Aida Wan; Lim, Seng Joe; Maskat, Mohamad Yusof

2016-11-01

Fucoidan is a biologically active polysaccharide that were made up of complex mixture of fucose, sulfate and uronic acid. This study was conducted to identify the volatile compositions of crude fucoidan and deodorized fucoidans extracted from brown seaweed Sargassum sp. (Fsar). The volatile compositions was also compared with a standard commercial fucoidan (Fysk). Fucoidan was extracted from Sargassum sp. originated in coastal area of Indonesia, by using a low pH acid extraction method. Approximately 20 mL of 1% freshly extracted fucoidan was then subjected to deodorization process by using three different method i.e., by treating it with 10 g activated carbon (Fac), 0.4 g ion exchange resin, Amberlite 67 (Fresin) and 2 mL of 1% calcium carbonate (FCaCO3) and incubated for 12 hrs before further analysis. Forty-six volatile compounds were successfully identified in all of the five samples by using Headspace-Solid Phase Microextraction (HS-SPME) and analysed by using Gas Chromatography Mass Spectrometer (GCMS). In Fsar, 72% of the total volatile constituents were identified as aromatic hydrocarbons, 23% hydrocarbons and 5% alcohols. In Fysk, all compounds detected are in group hydrocarbons. In Fsar, all of the compounds identified were classified as odor active compounds which had a contribution to unpleasant odor in fucoidan. After deodorization, 72% of aromatic hydrocarbons detected in Fsar were reported to be absent in all deodorized fucoidans. Both Fresin and FCaCO3 showed a reduction in peak area percentages of phenol, 2,4-bis (1,1-dimethylethyl)- from Fsar (1.30%) to 0.79 and 1.07% respectively. Meanwhile in Fac, no presence of phenol, 2,4-bis (1,1-dimethylethyl) was reported. These findings are essential to propel the advancement of research in deodorization technologies of marine products, especially fucoidans.

Volatiles formation in gelled emulsions enriched in polyunsaturated fatty acids during storage: type of oil and antioxidant.

PubMed

Gayoso, Lucía; Poyato, Candelaria; Calvo, María Isabel; Cavero, Rita Yolanda; Ansorena, Diana; Astiasarán, Iciar

2017-08-01

Gelled emulsions with carrageenan are a novel type of emulsion that could be used as a carrier of unsaturated fatty acids in functional foods formulations. Lipid degradation through volatile compounds was studied in gelled emulsions which were high in polyunsaturated oils (sunflower or algae oil) after 49 days of storage. Aqueous Lavandula latifolia extract was tested as a natural antioxidant. Analysis of the complete volatile profile of the samples resulted in a total of 40 compounds, classified in alkanes, alkenes, aldehydes, ketones, acids, alcohols, furans, terpenes and aromatic hydrocarbons. During storage, the formation of the volatile compounds was mostly related to the oxidation of the main fatty acids of the sunflower oil (linolenic acid) and the algae oil (docosahexaenoic acid). Despite the antioxidant capacity shown by the L. latifolia extract, its influence in the oxidative stability in terms of total volatiles was only noticed in sunflower oil gels ( p  < 0.05), where a significant decrease in the aldehydes fraction was found.

Polycyclic aromatic hydrocarbons - fate and long-range atmospheric transport studied using a global model, EMAC-SVOC

NASA Astrophysics Data System (ADS)

Octaviani, Mega; Tost, Holger; Lammel, Gerhard

2017-04-01

Polycyclic aromatic hydrocarbons (PAHs) are emitted by incomplete combustion from fossil fuel, vehicles, and biomass burning. They may persist in environmental compartments, pose a health hazard and may bio accumulate along food chains. The ECHAM/MESSy Atmospheric Chemistry (EMAC) model had been used to simulate global tropospheric, stratospheric chemistry and climate. In this study, we improve the model to include simulations of the transport and fate of semi-volatile organic compounds (SVOC). The EMAC-SVOC model takes into account essential environmental processes including gas-particle partitioning, dry and wet deposition, chemical and bio-degradation, and volatilization from sea surface, soils, vegetation, and snow. The model was evaluated against observational data in the Arctic, mid-latitudes, and tropics, and further applied to study total environmental lifetime and long-range transport potential (LRTP) of PAHs. We selected four compounds for study, spanning a wide range of volatility, i.e., phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene. Several LRTP indicators were investigated, including the Arctic contamination potential, meridional spreading, and zonal and meridional fluxes to remote regions.

[Volatile organic compounds concentrations and sources inside new air-conditioned bus].

PubMed

You, Ke-Wei; Ge, Yun-Shan; Qian, Yi-Xin; Liu, Wei; Feng, Bo; Zhang, Yan-Ni; Ning, Zhan-Wu; Hu, Bin; Zhao, Shou-Tang

2008-05-01

The distributing profile and concentration level inside new air-conditioned buses with 53 seats have been determined using the method of thermal desorption-capillary GC/MS under vehicle static conditions. Compounds were identified from their mass spectral data by using US National Institute of Standards and Technology (NIST02). The total numbers of identified components were 33 inside buses, including alkenes (15,45.4%), aromatic compounds (9,27.3%), alcohols (4,12.1%), ketones (3,9.1%) and esters (2,6.1%), especially in the range of C6-C10. The top 5 compounds measured inside buses were decane (8.01 mg/m3), 3-methylhexane (7.10 mg/m3), heptane (5.10 mg/m3), isoheptane (4.20 mg/m3) and 1-Methyl-3-ethylbenzene (3.56 mg/m3), and total volatile organic compounds (TVOC) > 52.5 mg/m3. The main sources of in-vehicle hydrocarbons and aromatic compounds comes from cabin components and interior trim materials (e.g., sealants, carpets, adhesives, paints, leather, plastics, PU foam and PE foam) that may retain certain VOCs during manufacturing, and/or emit these compounds over an extended period of time from off-gassing, aging-related breakdown products, heating/cooling and so on.

Organic contamination of ground water at Gas Works Park, Seattle, Washington

USGS Publications Warehouse

Turney, G.L.; Goerlitz, D.F.

1990-01-01

Gas Works Park, in Seattle, Washington, is located on the site of a coal and oil gasification plant that ceased operation in 1956. During operation, many types of wastes, including coal, tar, and oil, accumulated on-site. The park soil is currently (1986) contaminated with compounds such as polynuclear aromatic hydrocarbons, volatile organic compounds, trace metals, and cyanide. Analyses of water samples from a network of observation wells in the park indicate that these compounds are also present in the ground water. Polynuclear aromatic hydrocarbons and volatile organic compounds were identified in ground water samples in concentrations as large as 200 mg/L. Concentrations of organic compounds were largest where ground water was in contact with a non-aqueous phase liquid in the soil. Where no non-aqueous phase liquid was present, concentrations were much smaller, even if the ground water was in contact with contaminated soils. This condition is attributed to weathering processes in which soluble, low-molecular-weight organic compounds are preferentially dissolved from the non-aqueous phase liquid into the ground water. Where no non-aqueous phase liquid is present, only stained soils containing relatively insoluble, high-molecular-weight compounds remain. Concentrations of organic contaminants in the soils may still remain large.

Perchlorate and Volatiles in the Brine of Lake Vida (antarctica): Implication for the Analysis of Mars Sediments

NASA Astrophysics Data System (ADS)

Kenig, F. P. H.; Chou, L.; McKay, C.; Jackson, W. A.; Doran, P. T.; Murray, A. E.; Fritsen, C. H.

2015-12-01

A cold (-13.4 °C), saline (188 psu) evaporative brine is encapsulated in the thick (> 27 m) ice of Lake Vida (McMurdo Dry Valleys, Antarctica). The Lake Vida brine (LVBr), which contains abundant dissolved organic carbon (48.2 mmol/L), support an active but slow microbial community. LVBr contains oxychlorines with 50 μg/L of perchlorate and 11 μg/L of chlorate. The McMurdo Dry Valleys have often been considered as a good Mars analog. The oxychlorine-rich brine of Lake Vida constitutes a potential equivalent to perchlorate-rich preserved saline liquid water on Mars. We report here on the artifacts created by oxychlorines upon analysis of volatiles and volatile organic compounds (VOCs) of LVBr by direct immersion (DI) and head space (HS) solid phase micro extraction (SPME) gas chromatography-mass spectrometry (GCMS). We compare analytical blanks to a standard containing 40 μg/L of perchlorate and to actual LVBr sample runs. All blanks, perchlorate blanks and samples were analyzed using two types of SPME fibers, CarboxenTM/polydimethylsiloxane (PDMS) and divinylbenzene (DVB)/ PDMS. The similarities and differences between our results and those obtained by the Sample Analysis at Mars instruments of the rover Curiosity are discussed. The volatiles evolved from LVBr upon analysis with DI- and HS-SPME GCMS are dominated by CO2, dichloromethane, HCl, and volatile organic sulfur compounds (VOSCs, such as DMS, DMDS). The volatiles also include oxygenated compounds such as acids and ketones, aromatic compounds, hydrocarbons, chlorinated compounds (dominated by dichloromethane). Apart from the VOSCs, short chain hydrocarbons and some functionalized compounds derived from the brine itself, all compounds observed are artifacts formed upon oxychlorine breakdown in the injector of the GCMS. The distribution of aromatic compounds seems to be directly dependant on the type of SPME fiber used. The perchlorate blanks show a clear pattern of carbon limitation, likely affecting the type and abundance of compounds produced. This suggests that carbon limited perchlorates blanks are not satisfactory for comparison to the analysis of oxychlorine containing samples. Acknowledgment: NASA ASTEP NAG5-12889 (PTD), NSF awards ANT-0739681 (AEM, CHF) and ANT-0739698 (PTD, FK) supported this work.

The leaf volatile constituents of Isatis tinctoria by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry.

PubMed

Condurso, Cettina; Verzera, Antonella; Romeo, Vincenza; Ziino, Marisa; Trozzi, Alessandra; Ragusa, Salvatore

2006-08-01

The leaf volatile constituents of Isatis tinctoria L. (Brassicaceae) have been studied by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry (SPME/GC-MS). Seventy components were fully characterized by mass spectra, linear retention indices, and injection of standards; the average composition (ppm) as single components and classes of substances is reported. Aliphatic hydrocarbons, acids, alcohols, aldehydes and esters, aromatic aldehydes, esters and ethers, furans, isothiocyanates and thiocyanates, sulfurated compounds, nitriles, terpenes and sesquiterpenes were identified. Leaf volatiles in Isatis tinctoria L. were characterized by a high amount of isothiocyanates which accounted for about 40 % of the total volatile fraction. Isothiocyanates are important and characteristic flavour compounds in Brassica vegetables and the cancer chemo-protective attributes are recently responsible for their growing interest.

Evaluation of the volatile profile of Tuber liyuanum by HS-SPME with GC-MS.

PubMed

Liu, Changjiao; Li, Yu

2017-04-01

The volatile components of Tuber liyuanum were determined by HS-SPME with GC-MS for the first time. The effects of different fibre coating, extraction time, extraction temperature and sample amount were studied to get optimal extraction conditions. The optimal conditions were SPME fibre of Carboxen/PDMS, extraction time of 40 min, extraction temperature of 80 °C, sample amount of 2 g. Under these conditions 57 compounds in volatile of T. liyuanum were detected with a resemblance percentage above 80%. Aldehydes and aromatics were the main chemical families identified. The contribution of 3-Octanone(11.67%), phenylethyl alcohol (10.60%), isopentana (9.29%) and methylbutana (8.06%) for the total volatile profile were more significant in T. liyuanum than other compounds.

Formation of highly oxygenated organic molecules from aromatic compounds

NASA Astrophysics Data System (ADS)

Molteni, Ugo; Bianchi, Federico; Klein, Felix; El Haddad, Imad; Frege, Carla; Rossi, Michel J.; Dommen, Josef; Baltensperger, Urs

2018-02-01

Anthropogenic volatile organic compounds (AVOCs) often dominate the urban atmosphere and consist to a large degree of aromatic hydrocarbons (ArHCs), such as benzene, toluene, xylenes, and trimethylbenzenes, e.g., from the handling and combustion of fuels. These compounds are important precursors for the formation of secondary organic aerosol. Here we show that the oxidation of aromatics with OH leads to a subsequent autoxidation chain reaction forming highly oxygenated molecules (HOMs) with an O : C ratio of up to 1.09. This is exemplified for five single-ring ArHCs (benzene, toluene, o-/m-/p-xylene, mesitylene (1,3,5-trimethylbenzene) and ethylbenzene), as well as two conjugated polycyclic ArHCs (naphthalene and biphenyl). We report the elemental composition of the HOMs and show the differences in the oxidation patterns of these ArHCs. A potential pathway for the formation of these HOMs from aromatics is presented and discussed. We hypothesize that AVOCs may contribute substantially to new particle formation events that have been detected in urban areas.

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY

EPA Science Inventory

The Arizona Border Study, which measured levels of metals, pesticides, polynuclear aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs) in the Arizona counties bordering Mexico, is an extension of the Arizona National Human Exposure Assessment Survey (NHEXAS) Phase...

Impact of Listeria Inoculation and Aerated Steam Sanitization on Volatile Emissions of Whole Fresh Cantaloupes.

PubMed

Forney, Charles F; Fan, Lihua; Bezanson, Gregory S; Ells, Timothy C; LeBlanc, Denyse I; Fillmore, Sherry

2018-04-01

Rapid methods to detect bacterial pathogens on food and strategies to control them are needed to mitigate consumer risk. This study assessed volatile emissions from whole cantaloupe melons (Cucumis melo) as an indicator of Listeria contamination and in response to steam vapor decontamination. Cantaloupe were inoculated with Listeria innocua, a nonpathogenic surrogate for L. monocytogenes, then exposed to 85 °C steam for 240 s (4 min) followed by rapid chilling and storage for 0, 7, 10, or 14 days at 4, 7, or 10 °C. Volatile emissions from whole melons were collected on Carbopack B/Carboxen 1000 headspace collection tubes and analyzed by gas chromatography-mass spectroscopy following thermal desorption. Introduction of L. innocua to cantaloupe rind resulted in a reduction of aromatic compound emission. However, this response was not unique to Listeria contamination in that steam vapor treatment also reduced emission of these compounds. As well, steam vapor treatment diminished the number of viable Listeria and indigenous microflora while causing physiological injury to melon rind. Heat treatment had no significant effects on flesh firmness, color, titratable acidity, or soluble solids, but the production of typical aroma volatiles during postharvest ripening was inhibited. No unique volatile compounds were detected in Listeria contaminated melons. While changes in volatile emissions were associated with Listeria inoculation, they could not be differentiated from heat treatment effects. Results indicate that volatile emissions cannot be used as a diagnostic tool to identify Listeria contamination in whole cantaloupe melons. The detection of pathogen contamination on fresh produce is a continuing challenge. Using a nondestructive screening method, the presence of surrogate Listeria innocua on fresh whole cantaloupes was shown to alter the emissions of aromatic volatiles from whole cantaloupes. However, these altered emissions were not found to be unique to Listeria spp. and therefore cannot be used as a definitive indicator of Listeria contamination. © 2018 Institute of Food Technologists®.

Paleogene stratigraphy of the Solomons Island, Maryland corehole

USGS Publications Warehouse

Gibson, Thomas G.; Bybell, Laurel M.

1994-01-01

Purge and trap capillary gas chromatography/mass spectrometry is a rapid, precise, accurate method for determining volatile organic compounds in samples of surface water and ground water. The method can be used to determine 59 selected compounds, including chlorofluorohydrocarbons, aromatic hydrocarbons, and halogenated hydrocarbons. The volatile organic compounds are removed from the sample matrix by actively purging the sample with helium. The volatile organic compounds are collected onto a sorbant trap, thermally desorbed, separated by a Megabore gas chromatographic capillary column, ionized by electron impact, and determined by a full-scan quadrupole mass spectrometer. Compound identification is confirmed by the gas chromatographic retention time and by the resultant mass spectrum. Unknown compounds detected in a sample can be tentatively identified by comparing the unknown mass spectrum to reference spectra in the mass-spectra computer-data system library compiled by the National Institute of Standards and Technology. Method detection limits for the selected compounds range from 0.05 to 0.2 microgram per liter. Recoveries for the majority of the selected compounds ranged from 80 to 120 percent, with relative standard deviations of less than 10 percent.

Occupational health and safety assessment of exposure to jet fuel combustion products in air medical transport.

PubMed

MacDonald, Russell D; Thomas, Laura; Rusk, Frederick C; Marques, Shauna D; McGuire, Dan

2010-01-01

Transport medicine personnel are potentially exposed to jet fuel combustion products. Setting-specific data are required to determine whether this poses a risk. This study assessed exposure to jet fuel combustion products, compared various engine ignition scenarios, and determined methods to minimize exposure. The Beechcraft King Air B200 turboprop aircraft equipped with twin turbine engines, using a kerosene-based jet fuel (Jet A-1), was used to measure products of combustion during boarding, engine startup, and flight in three separate engine start scenarios ("shielded": internal engine start, door closed; "exposed": ground power unit start, door open; and "minimized": ground power unit right engine start, door open). Real-time continuous monitoring equipment was used for oxygen, carbon dioxide, carbon monoxide, nitrogen dioxide, hydrogen sulfide, sulfur dioxide, volatile organic compounds, and particulate matter. Integrated methods were used for aldehydes, polycyclic aromatic hydrocarbons, volatile organic compounds, and aliphatic hydrocarbons. Samples were taken in the paramedic breathing zone for approximately 60 minutes, starting just before the paramedics boarded the aircraft. Data were compared against regulated time-weighted exposure thresholds to determine the presence of potentially harmful products of combustion. Polycyclic aromatic hydrocarbons, aldehydes, volatile organic compounds, and aliphatic hydrocarbons were found at very low concentrations or beneath the limits of detection. There were significant differences in exposures to particulates, carbon monoxide, and total volatile organic compound between the "exposed" and "minimized" scenarios. Elevated concentrations of carbon monoxide and total volatile organic compounds were present during the ground power unit-assisted dual-engine start. There were no appreciable exposures during the "minimized" or "shielded" scenarios. Air medical personnel exposures to jet fuel combustion products were generally low and did not exceed established U.S. or Canadian health and safety exposure limits. Avoidance of ground power unit-assisted dual-engine starts and closing the hangar door prior to start minimize or eliminate the occupational exposure.

Biotreatment of Gaseous-Phase Volatile Organic Compounds

DTIC Science & Technology

1990-07-31

determined benzene to be degradable by methanogenic cultures acclimated to lignin-derived aromatic acids under strict anaerobic conditions. 5.3 CARBON...1986. Toluene and benzene transformation by ferulate - acclimated methanogenic consortia. Abstracts of the 86th Annual Meeting of the American Society

Flavoring Production in Kamut®, Quinoa and Wheat Doughs Fermented by Lactobacillus paracasei, Lactobacillus plantarum, and Lactobacillus brevis: A SPME-GC/MS Study.

PubMed

Di Renzo, Tiziana; Reale, Anna; Boscaino, Floriana; Messia, Maria C

2018-01-01

This study identified the odor-active compounds and the qualitative characteristics of doughs from "ancient" grains flours fermented by lactic acid bacteria. For this purpose doughs made with quinoa and Kamut® flours have been produced and inoculated with strains belonging to the species Lactobacillus paracasei, Lactobacillus plantarum and Lactobacillus brevis and compared with fermented doughs made from 100% wheat flour. The quality of the doughs was determined by assessment of pH, total titratable acidity, lactic acid bacteria growth and flavor compounds. The results showed that lactic acid bacteria used were able to grow in the different substrates reaching more than 9.0 log CFU/g after 24 h fermentation, although the best microbial growth was recorded in the doughs made with quinoa flour fermented with Lactobacillus paracasei I1. Good acidification and heterogeneous aromatic profile were recognized in all the doughs even if the volatile composition mainly derived from microbial specie. Among all the used strains, mostly Lactobacillus paracasei I1 positively contributed to the aromatic profile of the doughs, independently from flour type, producing the highest amount of different ketones such as, diacetyl, acetoin, 2,6-dimethyl-4-heptanone, 5-methyl-3-hexanone, 4-methyl-3-penten-2-one, volatile compounds highly appreciated in the bakery products for their buttery, fatty and fruity notes. So, the positive characteristic of Lactobacillus paracasei I1 to enhance the production of desired volatile compounds could make it suitable as adjunct culture starter in the bakery industry. Many differences in volatile organic compounds derived also by the type of flour used. Quinoa fermented doughs were characterized for specific nutty, roasted, acid and buttery tones derived from pyrazines, ketones and acid compounds whereas Kamut® fermented doughs were characterized for fruity, rose, green and sweet tones derived from aldehydes and ketones production. So, the use of quinoa and Kamut® flours opportunely fermented, as partial or complete substitution of wheat flour, may be interesting for producing more balanced bakery products with respect to nutritional aspects and to unique aromatic profile. Furthermore, the supplementation of these flours, rich in protein content and free amino acids, could represent an optimal substrate to enhance the growth of lactic acid bacteria used as starter culture in leavened bakery products.

Effects of irrigation over three years on the amino acid composition of Treixadura (Vitis vinifera L.) musts and wines, and on the aromatic composition and sensory profiles of its wines.

PubMed

Bouzas-Cid, Yolanda; Falqué, Elena; Orriols, Ignacio; Mirás-Avalos, José M

2018-02-01

Amino acids and volatile compounds play an important role in wine aroma and sensory characteristics. The concentrations of these compounds might be altered by climate interanual variability and by management practices such as irrigation. The aim of the current study was to assess the amino acid profile of musts and wines, volatile composition and sensory profile of wines from Vitis vinifera (L.) cultivar 'Treixadura' obtained from vines under rain-fed and irrigation conditions over three consecutive vintages (2012-2014). Musts and wines from the irrigation treatment tended to be higher in acidity than those from rain-fed. However, amino acid and aromatic profiles were mostly affected by climate conditions of each year; although irrigation exerted a significant effect on several compounds (proline, cysteine, tryptophan, phenylalanine, α-terpineol and geraniol). Wines from both treatments received similar marks in the sensory tests, suggesting that irrigation did not greatly modify wine quality under the conditions of this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of Volatiles by Odor Activity Value and Phenolics of cv. Ayvalik Early-Harvest Olive Oil

PubMed Central

Guclu, Gamze; Sevindik, Onur; Kelebek, Hasim; Selli, Serkan

2016-01-01

Ayvalik is an important olive cultivar producing high quality oils in Turkey. In the present study, volatile and phenolic compositions of early-harvest extra virgin olive oil (cv. Ayvalik) were determined. The solvent-assisted flavor evaporation (SAFE) technique was used for the extraction of volatile components. The aromatic extract obtained by SAFE was representative of the olive oil odor. A total of 32 aroma compounds, including alcohols, aldehydes, terpenes, esters, and an acid, were identified in the olive oil. Aldehydes and alcohols were qualitatively and quantitatively the most dominant volatiles in the oil sample. Of these, six volatile components presented odor activity values (OAVs) greater than one, with (Z)-3-hexenal (green), hexanal (green-sweet) and nonanal (fatty-pungent) being those with the highest OAVs in olive oil. A total of 14 phenolic compounds were identified and quantified by liquid chromatography combined with a diode array detector and ion spray mass spectrometry. The major phenolic compounds were found as 3,4-DHPEA-EDA, 3,4-DHPEA-EA and p-HPEA-EDA. PMID:28231141

Bromination of aromatic compounds by residual bromide in sodium chloride matrix modifier salt during heated headspace GC/MS analysis.

PubMed

Fine, Dennis D; Ko, Saebom; Huling, Scott

2013-12-15

Analytical artifacts attributed to the bromination of toluene, xylenes, and trimethylbenzenes were found during the heated headspace gas chromatography/mass spectrometry (GC/MS) analysis of aqueous samples. The aqueous samples were produced from Fenton-like chemical oxidation reactions and contained aromatic compounds, hydrogen peroxide (H2O2), and ferric sulfate. Prior to GC/MS headspace analysis, the samples were acidified (pH<2), and sodium chloride was amended to the headspace vial as a matrix modifier. The brominated artifacts were generated during heated headspace analysis. Further, when samples were spiked with a mixture of volatile chlorinated and aromatic compounds (50 µg/L), poor spike recoveries of toluene and xylenes occurred, and in some cases complete loss of trimethylbenzenes and naphthalene resulted. Where poor recovery of aromatic spike compounds occurred, brominated aromatic compounds were found. The only significant source of bromine in the reaction scheme is the bromide typically present (<0.01% w/w) in the sodium chloride amended to the samples. Conversely, brominated artifacts were absent when a buffered salt mixture composed of sodium chloride and potassium phosphate dibasic/monobasic was used as a matrix modifier and raised the sample pH (pH~6). This indicated that the brominated artifacts resulted from the reaction of the aromatic compounds with BrCl, which was formed by the reaction of H2O2, chloride, and bromide under acidic conditions. An alternative matrix modifier salt is recommended that prevents the bromination reaction and avoids these deleterious effects on sample integrity during headspace analysis. Published by Elsevier B.V.

Discriminative stimulus effects of inhaled1,1,1-trichloroethane in mice: comparison to other hydrocarbon vapors and volatile anesthetics

PubMed Central

Shelton, Keith L.

2009-01-01

Rationale Because the toxicity of many inhalants precludes evaluation in humans, drug discrimination, an animal model of subjective effects, can be used to gain insights on their poorly understood abuse-related effects. Objectives The purpose of the present study was to train a prototypic inhalant that has known abuse liability, 1,1,1-trichloroethane (TCE), as a discriminative stimulus in mice and compare it to other classes of inhalants. Methods Eight B6SJLF1/J mice were trained to discriminate 10 min of exposure to 12000 ppm inhaled TCE vapor from air and seven mice were trained to discriminate 4000 ppm TCE from air. Tests were then conducted to characterize the discriminative stimulus of TCE and to compare it to representative aromatic and chlorinated hydrocarbon vapors, volatile halogenated anesthetics as well as an odorant compound. Results Only the 12000 ppm TCE versus air discrimination group exhibited sufficient discrimination accuracy for substitution testing. TCE vapor concentration- and exposure time-dependently substituted for the 12000 ppm TCE vapor training stimulus. Full substitution was produced by trichloroethylene, toluene, enflurane and sevoflurane. Varying degrees of partial substitution were produced by the other volatile test compounds. The odorant, 2-butanol, did not produce any substitution for TCE. Conclusions The discriminative stimulus effects of TCE are shared fully or partially by chlorinated and aromatic hydrocarbons as well as by halogenated volatile anesthetics. However, these compounds can be differentiated from TCE both quantitatively and qualitatively. It appears that the degree of similarity is not solely a function of chemical classification but may also be dependent upon the neurochemical effects of the individual compounds. PMID:18972104

Hydrolates from lavender (Lavandula angustifolia)--their chemical composition as well as aromatic, antimicrobial and antioxidant properties.

PubMed

Prusinowska, Renata; Śmigielski, Krzysztof; Stobiecka, Agnieszka; Kunicka-Styczyńska, Alina

2016-01-01

It was shown that the method for obtaining hydrolates from lavender (Lavandula angustifolia) influences the content of active compounds and the aromatic, antimicrobial and antioxidant properties of the hydrolates. The content of volatile organic compounds ranged from 9.12 to 97.23 mg/100 mL of hydrolate. Lavender hydrolate variants showed low antimicrobial activity (from 0% to 0.05%). The radical scavenging activity of DPPH was from 3.6 ± 0.5% to 3.8 ± 0.6% and oxygen radical absorbance capacity (ORAC(FL)) results were from 0 to 266 μM Trolox equivalent, depending on the hydrolate variant.

Qualitative and quantitative prediction of volatile compounds from initial amino acid profiles in Korean rice wine (makgeolli) model.

PubMed

Kang, Bo-Sik; Lee, Jang-Eun; Park, Hyun-Jin

2014-06-01

In Korean rice wine (makgeolli) model, we tried to develop a prediction model capable of eliciting a quantitative relationship between initial amino acids in makgeolli mash and major aromatic compounds, such as fusel alcohols, their acetate esters, and ethyl esters of fatty acids, in makgeolli brewed. Mass-spectrometry-based electronic nose (MS-EN) was used to qualitatively discriminate between makgeollis made from makgeolli mashes with different amino acid compositions. Following this measurement, headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (GC-MS) combined with partial least-squares regression (PLSR) method was employed to quantitatively correlate amino acid composition of makgeolli mash with major aromatic compounds evolved during makgeolli fermentation. In qualitative prediction with MS-EN analysis, the makgeollis were well discriminated according to the volatile compounds derived from amino acids of makgeolli mash. Twenty-seven ion fragments with mass-to-charge ratio (m/z) of 55 to 98 amu were responsible for the discrimination. In GC-MS combined with PLSR method, a quantitative approach between the initial amino acids of makgeolli mash and the fusel compounds of makgeolli demonstrated that coefficient of determination (R(2)) of most of the fusel compounds ranged from 0.77 to 0.94 in good correlation, except for 2-phenylethanol (R(2) = 0.21), whereas R(2) for ethyl esters of MCFAs including ethyl caproate, ethyl caprylate, and ethyl caprate was 0.17 to 0.40 in poor correlation. The amino acids have been known to affect the aroma in alcoholic beverages. In this study, we demonstrated that an electronic nose qualitatively differentiated Korean rice wines (makgeollis) by their volatile compounds evolved from amino acids with rapidity and reproducibility and successively, a quantitative correlation with acceptable R2 between amino acids and fusel compounds could be established via HS-SPME GC-MS combined with partial least-squares regression. Our approach for predicting the quantities of volatile compounds in the finished product from initial condition of fermentation will give an insight to food researchers to modify and optimize the qualities of the corresponding products. © 2014 Institute of Food Technologists®

Aroma profile of malbec red wines from La Mancha region: Chemical and sensory characterization.

PubMed

Sánchez-Palomo, E; Trujillo, M; García Ruiz, A; González Viñas, M A

2017-10-01

The aroma of La Mancha Malbec red wines over four consecutive vintages was characterized by chemical and sensory analysis. Solid phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS) were used to isolate and analyze free volatile compounds. Quantitative Descriptive Sensory Analysis (QDA) was carried out to characterize the sensory aroma profile. A total of 79 free volatile compounds were identified and quantified in the wines over these four vintages. Volatile aroma compounds were classified into seven aromatic series and their odour activity values were calculated in order to determine the aroma impact compounds in these wines. The aroma sensory profile of these wines was characterized by red fruit, fresh, prune, liquorice, clove, caramel, leather, tobacco and coffee aromas. This study provides a complete aroma characterization of La Mancha Malbec red wines and it is proposed that these wines can be considered as an alternative to wines from traditional grape varieties of this region. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of corn processing and wet distiller’s grains with solubles on odorous volatile organic compound emissions from urine and feces of beef cattle

USDA-ARS?s Scientific Manuscript database

Wet distiller’s grains with solubles (WDGS) are a common feed ingredient in beef feedlot diets, but the excess nitrogen in these diets creates air quality issues, primarily due to the aromatic compounds emitted during fermentation of excreted protein. Use of high-moisture corn (HMC) instead of dry-r...

Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

EPA Science Inventory

Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are not. Thus, we examined the mutagenicity in Salmonella TA100 of photochemical atmospheres generated in a steady-state a...

Evaluation of non-enteric sources of non-methane volatile organic compound (NMVOC) emissions from dairies

NASA Astrophysics Data System (ADS)

Chung, Myeong Y.; Beene, Matt; Ashkan, Shawn; Krauter, Charles; Hasson, Alam S.

2010-02-01

Dairies are believed to be a major source of volatile organic compounds (VOC) in Central California, but few studies have characterized VOC emissions from these facilities. In this work, samples were collected from six sources of VOCs (Silage, Total Mixed Rations, Lagoons, Flushing Lanes, Open Lots and Bedding) at six dairies in Central California during 2006-2007 using emission isolation flux chambers and polished stainless steel canisters. Samples were analyzed by gas chromatography/mass spectrometry and gas chromatography/flame ionization detection. Forty-eight VOCs were identified and quantified in the samples, including alcohols, carbonyls, alkanes and aromatics. Silage and Total Mixed Rations are the dominant sources of VOCs tested, with ethanol as the major VOC present. Emissions from the remaining sources are two to three orders of magnitude smaller, with carbonyls and aromatics as the main components. The data suggest that animal feed rather than animal waste are the main source of non-enteric VOC emissions from dairies.

Antioxidant effect of aromatic volatiles emitted by Lavandula dentata, Mentha spicata, and M. piperita on mouse subjected to low oxygen condition.

PubMed

Hu, Zenghui; Wang, Chunling; Shen, Hong; Zhang, Kezhong; Leng, Pingsheng

2017-12-01

This study aims to investigate the antioxidant effect of aromatic volatiles of three common aromatic plants, Lavandula dentata, Mentha spicata, and M. piperita. In this study, kunming mice subjected to low oxygen condition were treated with the volatiles emitted from these aromatic plants through inhalation administration. Then the blood cell counts, and the activities and gene expressions of antioxidant enzymes in different tissues were tested. The results showed that low oxygen increased the counts of red blood cells, white blood cells, and blood platelets of mice, and aromatic volatiles decreased their counts. Exposure to aromatic volatiles resulted in decreases in the malonaldehyde contents, and increases in the activities and gene expressions of superoxide dismutase, glutathione peroxidase, and catalase in different tissues under low oxygen. In addition, as the main component of aromatic volatiles, eucalyptol was the potential source that imparted positive antioxidant effect.

Quantity and quality of stormwater collected from selected stormwater outfalls at industrial sites, Fort Gordon, Georgia, 2012

USGS Publications Warehouse

Nagle, Doug D.

2013-01-01

Samples from sites SWR11–3, SWR11–4, and SWR11–5 were analyzed for 83 volatile and semivolatile organic compounds. Eight polycyclic aromatic hydrocarbon compounds, benzo[a]pyrene, benzo[b]fluoranthene, benzo[ghi]perylene, benzo[k]fluoranthene, chrysene, indeno[1,2,3-cd]pyrene, phenanthrene, and pyrene, were detected at all three sites. Of the 86 volatile and semivolatile organic compounds that were analyzed in stormwater samples from heating and cooling sites, 15 (18 percent) were detected at site SWR11–3, 12 (14 percent) were detected at site SWR11–4, and 17 (20 percent) were detected at site SWR11–5.

Characterization of volatile aroma compounds in different brewing barley cultivars.

PubMed

Dong, Liang; Hou, Yingmin; Li, Feng; Piao, Yongzhe; Zhang, Xiao; Zhang, Xiaoyu; Li, Cheng; Zhao, Changxin

2015-03-30

Beer is a popular alcoholic malt beverage resulting from fermentation of the aqueous extract of malted barley with hops. The aroma of brewing barley impacts the flavor of beer indirectly, because some flavor compounds or their precursors in beer come from the barley. The objectives of this research were to study volatile profiles and to characterize odor-active compounds of brewing barley in order to determine the variability of the aroma composition among different brewing barley cultivars. Forty-one volatiles comprising aldehydes, ketones, alcohols, organic acids, aromatic compounds and furans were identified using solid phase microextraction combined with gas chromatography/mass spectrometry, among which aldehydes, alcohols and ketones were quantitatively in greatest abundance. Quantitative measurements performed by means of solvent extraction and calculation of odor activity values revealed that acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, hexanal, heptanal, octanal, nonanal, 3-methyl-1-butanol, cyclopentanol, 2,3-butanedione, 2,3-pentanedione, 2-heptanone, acetic acid, ethyl acetate, 2-pentylfuran and benzeneacetaldehyde, whose concentrations exceeded their odor thresholds, could be considered as odor-active compounds of brewing barley. Principal component analysis was employed to evaluate the differences among cultivars. The results demonstrated that the volatile profile based on the concentrations of aroma compounds enabled good differentiation of most barley cultivars. © 2014 Society of Chemical Industry.

Predominant yeasts in Chinese traditional sourdough and their influence on aroma formation in Chinese steamed bread.

PubMed

Liu, Tongjie; Li, Yang; Sadiq, Faizan A; Yang, Huanyi; Gu, Jingsi; Yuan, Lei; Lee, Yuan Kun; He, Guoqing

2018-03-01

A total of 105 yeast isolates was obtained from 15 sourdough samples collected from different regions in China and subjected to random amplified polymorphic DNA (RAPD) analysis. Six species were identified including Pichia membranifaciens, which has not previously been reported in Chinese sourdoughs. Different species of yeast were used in single-culture fermentation to make Chinese steamed bread (CSB). The volatiles of the CSB were captured by solid-phase microextraction method, separated and identified by gas chromatography-mass spectrometry. In total, 41 volatile compounds were found in all the steamed breads. All CSBs showed a similar volatile profile; however, significant differences in the quantity of some volatile compounds were seen among the CSB fermented by different yeast species. A partial least squares discriminant analysis showed that the CSBs could be separated by their characteristic volatile profiles. The study suggested that the aromatic properties of CSB are determined by the yeast used. Copyright © 2017 Elsevier Ltd. All rights reserved.

Olfactometric determination of the most potent odor-active compounds in salmon muscle (Salmo salar) smoked by using four smoke generation techniques.

PubMed

Varlet, Vincent; Serot, Thierry; Cardinal, Mireille; Knockaert, Camille; Prost, Carole

2007-05-30

The volatile compounds of salmon fillets smoked according to four smoked generation techniques (smoldering, thermostated plates, friction, and liquid smoke) were investigated. The main odor-active compounds were identified by gas chromatography coupled with olfactometry and mass spectrometry. Only the odorant volatile compounds detected by at least six judges (out of eight) were identified as potent odorants. Phenolic compounds and guaiacol derivatives were the most detected compounds in the olfactometric profile whatever the smoking process and could constitute the smoky odorant skeleton of these products. They were recovered in the aromatic extracts of salmon smoked by smoldering and by friction, which were characterized by 18 and 25 odor-active compounds, respectively. Furannic compounds were more detected in products smoked with thermostated plates characterized by 26 odorants compounds. Finally, the 27 odorants of products treated with liquid smoke were significantly different from the three others techniques applying wood pyrolysis because pyridine derivatives and lipid oxidation products were perceived in the aroma profile.

[Influence of liquid or solid culture conditions on the volatile components of mycelia of Isariacateinannulata].

PubMed

Zhang, Delong; Wang, Xiaodong; Lu, Ruili; Li, Kangle; Hu, Fenglin

2011-12-01

To determine the volatile components of mycelia of Isaria cateinannulata cultured under different culture conditions, and to analyze the relationships between the culture conditions and volatile metabolites. Mycelia were cultured in solid plates with SDAY medium and liquid shake flasks with SDY medium. The culture conditions were at 25 degrees C and 8 days. Volatile components in the mycelia of I. cateinannulata were extracted with simultaneous distillation extraction and analyzed by gas chromatography-mass spectrometry. Alkenes, alkanes, heterocyclic and polycyclic aromatic hydrocarbons (PAH) were existed abundantly both in the mycelia of liquid and solid cultures, but the kinds and relative concentrations of the volatile components in mycelia of liquid and solid cultures were very different. Forty-one compounds were identified from the mycelia of solid culture and 32 compounds were identified from the mycelia of liquid culture. Esters, quinones and oximes were only found in solid cultured mycelia whereas carboxylic acids were only discovered in the mycelia of liquid culture. At the same time, mycelia of liquid culture contained much more phenols. The most abundant compounds in mycelia of liquid and solid cultures were hydrocarbons. The volatile extracts of solid cultured mycelia contained 57.6% alkenes and 9.19% alkanes. The volatile extracts of liquid cultured mycelia contained 7.85% alkenes and 22.4% alkanes. Liquid or solid culture conditions influenced the volatile components of mycelia of I. cateinannulata.

Two Dimensional Host-Guest Metal-Organic Framework Sensor with High Selectivity and Sensitivity to Picric Acid.

PubMed

Bagheri, Minoo; Masoomi, Mohammad Yaser; Morsali, Ali; Schoedel, Alexander

2016-08-24

A dye-sensitized metal-organic framework, TMU-5S, was synthesized based on introducing the laser dye Rhodamine B into the porous framework TMU-5. TMU-5S was investigated as a ratiometric fluorescent sensor for the detection of explosive nitro aromatic compounds and showed four times greater selectivity to picric acid than any state-of-the-art luminescent-based sensor. Moreover, it can selectively discriminate picric acid concentrations in the presence of other nitro aromatics and volatile organic compounds. Our findings indicate that using this sensor in two dimensions leads to a greatly reduced environmental interference response and thus creates exceptional sensitivity toward explosive molecules with a fast response.

Sensory Characteristics and Volatile Components of Dry Dog Foods Manufactured with Sorghum Fractions.

PubMed

Donfrancesco, Brizio Di; Koppel, Kadri

2017-06-17

Descriptive sensory analysis and gas chromatography-mass spectrometry (GC-MS) with a modified headspace solid-phase microextraction (SPME) method was performed on three extruded dry dog food diets manufactured with different fractions of red sorghum and a control diet containing corn, brewer's rice, and wheat as a grain source in order to determine the effect of sorghum fractions on dry dog food sensory properties. The aroma compounds and flavor profiles of samples were similar with small differences, such as higher toasted aroma notes, and musty and dusty flavor in the mill-feed sample. A total of 37 compounds were tentatively identified and semi-quantified. Aldehydes were the major group present in the samples. The total volatile concentration was low, reflecting the mild aroma of the samples. Partial least squares regression was performed to identify correlations between sensory characteristics and detected aroma compounds. Possible relationships, such as hexanal and oxidized oil, and broth aromatics were identified. Volatile compounds were also associated with earthy, musty, and meaty aromas and flavor notes. This study showed that extruded dry dog foods manufactured with different red sorghum fractions had similar aroma, flavor, and volatile profiles.

Methionine catabolism and production of volatile sulphur compounds by OEnococcus oeni.

PubMed

Pripis-Nicolau, L; de Revel, G; Bertrand, A; Lonvaud-Funel, A

2004-01-01

During malolactic fermentation (MLF), the secondary metabolisms of lactic acid bacteria (LAB) contribute to the organoleptic modification of wine. To understand the contribution of MLF, we evaluated the capacity of various wine LAB to metabolize methionine. Using gas chromatography (GC) coupled either with mass spectrometry (MS) or a flame photometry detector in sulphur mode (FPD), we studied this metabolism in laboratory media and wine. In laboratory media, several LAB isolated from wine were able to metabolize methionine. They formed methanethiol, dimethyl disulphide, 3-(methylsulphanyl)propan-1-ol and 3-(methylsulphanyl)propionic acid. These are known to have powerful characteristic odours and play a role in the aromatic complexity of wine. In various red wines, after MLF only the 3-(methylsulphanyl)propionic acid concentration increased significantly, as verified with several commercial starter cultures. This compound, which is characterized by chocolate and roasted odours, could contribute to the aromatic complexity produced by MLF. This study shows that LAB isolated from wine, especially OEnococcus oeni strains, the major species in MLF, are able to metabolize methionine to form volatile sulphur compounds. This is the first study to demonstrate the capacity of wine LAB to metabolize methionine.

Essential oil composition of three Peperomia species from the Amazon, Brazil.

PubMed

de Lira, Patricia Natália B; da Silva, Joyce Kelly R; Andrade, Eloisa Helena A; Sousa, Pergentino José; Silva, Nayla N S; Maia, José Guilherme S

2009-03-01

The essential oils of three species of Peperomia from the Amazon, Brazil, were hydrodistilled and their 96 volatile constituents identified by GC and GC-MS. The main constituents found in the oil of P. macrostachya were epi-alpha-bisabolol (15.9%), caryophyllene oxide (12.9%), myristicin (7.6%), an aromatic compound (6.6%) and limonene (5.4%). The oil of P. pellucida was dominated by dillapiole (55.3%), (E)-caryophyllene (14.3%) and carotol (8.1%). The major volatile found in the oil of P. rotundifolia was decanal (43.3%), probably a fatty acid-derived compound, followed by dihydro-P3-santalol (9.0%), (E)-nerolidol (7.9%) and limonene (7.7%). The aromatic compounds elemicin, myristicin, apiole, dillapiole and safrole identified in these Peperomia species has been found also in Amazon Piper species. The oils and methanol extracts showed high brine shrimp larvicidal activities. The oil of P. rotundifolia (LC50 = 1.9 +/- 0.1 microg/mL) was the more toxic, followed by the extract of P. pellucida (LC50 = 2.4 +/- 0.5 microg/mL) and the oil of P. macrostachya (LC50 = 9.0 +/- 0.4 microg/mL), therefore with important biological properties.

SELECTIVE DETECTION OF VOLATILE AROMATIC COMPOUNDS USING A COMPACT LASER IONIZATION DETECTOR WITH FAST GAS CHROMATOGRAPHY (R829415E02)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Toxic remediation

DOEpatents

Matthews, Stephen M.; Schonberg, Russell G.; Fadness, David R.

1994-01-01

What is disclosed is a novel toxic waste remediation system designed to provide on-site destruction of a wide variety of hazardous organic volatile hydrocarbons, including but not limited to halogenated and aromatic hydrocarbons in the vapor phase. This invention utilizes a detoxification plenum and radiation treatment which transforms hazardous organic compounds into non-hazardous substances.

Volatiles released from Vaccinium corymbosum were attractive to Aegorhinus superciliosus (Coleoptera: Curculionidae) in an olfactometric bioassay.

PubMed

Parra, Leonardo; Mutis, Ana; Ceballos, Ricardo; Lizama, Marcelo; Pardo, Fernando; Perich, Fernando; Quiroz, Andrés

2009-06-01

The objective of this study was to evaluate the role of host volatiles in the relationship between a blueberry plant Vaccinium corymbosum L. and the raspberry weevil Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae), the principal pest of blueberry in the south of Chile. Volatiles from the aerial part of different phenological stages of the host were collected on Porapak Q and analyzed by coupled gas chromatography-mass spectrometry (GC-MS). Several chemical groups were identified including green leaf volatiles, aromatic compounds, and terpenes. The olfactometric responses of A. superciliosus toward different odor sources were studied in a four-arm olfactometer. Blueberry shoots at the phenological stages of fruit set, and blue-pink fruit color elicited the greatest behavioral responses from weevils. Five compounds (2-nonanone, eucalyptol, R- and S-limonene, and 4-ethyl benzaldehyde) elicited an attractant behavioral response from A. superciliosus. The results suggest the host location behavior of A. superciliosus could be mediated by volatiles derived from V. corymbosum. This work has identified a number of compounds with which it is possible to develop a lure for the principal pest of blueberry in southern Chile.

Profiles of Volatile Flavor Compounds in Milk Fermented with Different Proportional Combinations of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus.

PubMed

Dan, Tong; Wang, Dan; Wu, Shimei; Jin, Rulin; Ren, Weiyi; Sun, Tiansong

2017-09-29

Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus are key factors in the fermentation process and the final quality of dairy products worldwide. This study was performed to investigate the effects of the proportions of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus isolated from traditionally fermented dairy products in China and Mongolia on the profile of volatile compounds produced in samples. Six proportional combinations (1:1, 1:10, 1:50, 1:100, 1:1000, and 1:10,000) of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 were considered, and the volatiles were identified and quantified by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) against an internal standard. In total, 89 volatile flavor compounds, consisting of aldehydes, ketones, acids, alcohols, esters, and aromatic hydrocarbons, were identified. Among these, some key flavor volatile compounds were identified, including acetaldehyde, 3-methylbutanal, acetoin, 2-heptanone, acetic acid, butanoic acid, and 3-methyl-1-butanol. The of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 influenced the type and concentration of volatiles produced. In particular, aldehydes and ketones were present at higher concentrations in the 1:1000 treatment combination than in the other combinations. Our findings emphasize the importance of selecting the appropriate proportions of L. delbrueckii subsp. bulgaricus and S. thermophilus for the starter culture in determining the final profile of volatiles and the overall flavor of dairy products.

The pollution characteristics of odor, volatile organochlorinated compounds and polycyclic aromatic hydrocarbons emitted from plastic waste recycling plants.

PubMed

Tsai, Chung-Jung; Chen, Mei-Lien; Chang, Keng-Fu; Chang, Fu-Kuei; Mao, I-Fang

2009-02-01

Plastic waste treatment trends toward recycling in many countries; however, the melting process in the facilities which adopt material recycling method for treating plastic waste may emit toxicants and cause sensory annoyance. The objectives of this study were to analyze the pollution characteristics of the emissions from the plastic waste recycling plants, particularly in harmful volatile organochlorinated compounds, polycyclic aromatic hydrocarbons (PAHs), odor levels and critical odorants. Ten large recycling plants were selected for analysis of odor concentration (OC), volatile organic compounds (VOCs) and PAHs inside and outside the plants using olfactometry, gas chromatography-mass spectrometry and high performance liquid chromatography-fluorescence detector, respectively. The olfactometric results showed that the melting processes used for treating polyethylene/polypropylene (PE/PP) and polyvinyl chloride (PVC) plastic waste significantly produced malodor, and the odor levels at downwind boundaries were 100-229 OC, which all exceeded Taiwan's EPA standard of 50 OC. Toluene, ethylbenzene, 4-methyl-2-pentanone, methyl methacrylate and acrolein accounted for most odors compared to numerous VOCs. Sixteen organochlorinated compounds were measured in the ambient air emitted from the PVC plastic waste recycling plant and total concentrations were 245-553 microg m(-3); most were vinyl chloride, chloroform and trichloroethylene. Concentrations of PAHs inside the PE/PP plant were 8.97-252.16 ng m(-3), in which the maximum level were 20-fold higher than the levels detected from boundaries. Most of these recycling plants simply used filter to treat the melting fumes, and this could not efficiently eliminate the gaseous compounds and malodor. Improved exhaust air pollution control were strongly recommended in these industries.

Exposure to volatile organic compounds for individuals with occupations associated with potential exposure to motor vehicle exhaust and/or gasoline vapor emissions.

PubMed

Jo, W K; Song, K B

2001-03-26

Workers who work near volatile organic compounds (VOCs) source(s), motor vehicle exhausts and/or gasoline vapor emissions, are suspected to be exposed to highly-elevated VOC levels during their work-time. This study confirmed this suspicion and evaluated the work-time exposure VOCs for traffic police officers, parking garage attendants, service station attendants, roadside storekeepers and underground storekeepers, by measuring the concentrations of six aromatic VOCs in workplace air, or personal air and breath samples. For nearly all target VOCs, the post-work breath concentrations of the workers were slightly or significantly higher than the pre-work breath concentrations, depending on the compound and occupation. Furthermore, both the pre- and post-work breath concentrations of the workers showed elevated levels compared with a control group of college students. The post-work breath concentrations were significantly correlated with the personal air concentrations, while the pre-work breath concentrations were not. Smoking workers were not always exposed to higher aromatic VOC levels than non-smoking workers. The breath and personal air concentrations for all the target compounds were both higher for underground parking garage attendants than for ground-level parking attendants. For all the target compounds except toluene, storekeepers exhibited similar levels of exposure for all store types. Print shopkeepers recorded the highest toluene exposure.

Sorption of organic gases in a furnished room

NASA Astrophysics Data System (ADS)

Singer, Brett C.; Revzan, Kenneth L.; Hotchi, Toshifumi; Hodgson, Alfred T.; Brown, Nancy J.

We present experimental data and semi-empirical models describing the sorption of organic gases in a simulated indoor residential environment. Two replicate experiments were conducted with 20 volatile organic compounds (VOCs) in a 50-m 3 room finished with painted wallboard, carpet and cushion, draperies and furnishings. The VOCs span a wide volatility range and include ten hazardous air pollutants. VOCs were introduced to the static chamber as a pulse and their gas-phase concentrations were measured during a net adsorption period and a subsequent net desorption period. Three sorption models were fit to the measured concentrations for each compound to determine the simplest formulation needed to adequately describe the observed behavior. Sorption parameter values were determined by fitting the models to adsorption period data then checked by comparing measured and predicted behavior during desorption. The adequacy of each model was evaluated using a goodness of fit parameter calculated for each period. Results indicate that sorption usually does not greatly affect indoor concentrations of methyl- tert-butyl ether, 2-butanone, isoprene and benzene. In contrast, sorption appears to be a relevant indoor process for many of the VOCs studied, including C 8-C 10 aromatic hydrocarbons (HC), terpenes, and pyridine. These compounds sorbed at rates close to typical residential air change rates and exhibited substantial sorptive partitioning at equilibrium. Polycyclic aromatic HCs, aromatic alcohols, ethenylpyridine and nicotine initially adsorbed to surfaces at rates of 1.5->6 h -1 and partitioned 95->99% in the sorbed phase at equilibrium.

Enhanced Characterization of the Smell of Death by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GCxGC-TOFMS)

PubMed Central

Dekeirsschieter, Jessica; Stefanuto, Pierre-Hugues; Brasseur, Catherine; Haubruge, Eric; Focant, Jean-François

2012-01-01

Soon after death, the decay process of mammalian soft tissues begins and leads to the release of cadaveric volatile compounds in the surrounding environment. The study of postmortem decomposition products is an emerging field of study in forensic science. However, a better knowledge of the smell of death and its volatile constituents may have many applications in forensic sciences. Domestic pigs are the most widely used human body analogues in forensic experiments, mainly due to ethical restrictions. Indeed, decomposition trials on human corpses are restricted in many countries worldwide. This article reports on the use of comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) for thanatochemistry applications. A total of 832 VOCs released by a decaying pig carcass in terrestrial ecosystem, i.e. a forest biotope, were identified by GCxGC-TOFMS. These postmortem compounds belong to many kinds of chemical class, mainly oxygen compounds (alcohols, acids, ketones, aldehydes, esters), sulfur and nitrogen compounds, aromatic compounds such as phenolic molecules and hydrocarbons. The use of GCxGC-TOFMS in study of postmortem volatile compounds instead of conventional GC-MS was successful. PMID:22723918

Induction of stress volatiles and changes in essential oil content and composition upon microwave exposure in the aromatic plant Ocimum basilicum.

PubMed

Lung, Ildikó; Soran, Maria-Loredana; Opriş, Ocsana; Truşcă, Mihail Radu Cătălin; Niinemets, Ülo; Copolovici, Lucian

2016-11-01

Exposure to sustained low intensity microwaves can constitute a stress for the plants, but its effects on plant secondary chemistry are poorly known. We studied the influence of GSM and WLAN-frequency microwaves on emissions of volatile organic compounds and content of essential oil in the aromatic plant Ocimum basilicum L. hypothesizing that microwave exposure leads to enhanced emissions of stress volatiles and overall greater investment in secondary compounds. Compared to the control plants, microwave irradiation led to decreased emissions of β-pinene, α-phellandrene, bornyl acetate, β-myrcene, α-caryophyllene and benzaldehyde, but increased emissions of eucalyptol, estragole, caryophyllene oxide, and α-bergamotene. The highest increase in emission, 21 times greater compared to control, was observed for caryophyllene oxide. The irradiation resulted in increases in the essential oil content, except for the content of phytol which decreased by 41% in the case of GSM-frequency, and 82% in the case of WLAN-frequency microwave irradiation. The strongest increase in response to WLAN irradiation, >17 times greater, was observed for hexadecane and octane contents. Comparisons of volatile compositions by multivariate analyses demonstrated a clear separation of different irradiance treatments, and according to the changes in the volatile emissions, the WLAN-frequency irradiation represented a more severe stress than the GSM-frequency irradiation. Overall, these results demonstrating important modifications in the emission rates, essential oil content and composition indicate that microwave irradiation influences the quality of herbage of this economically important spice plant. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of mechanical wounding on essential oil composition and emission of volatiles from Minthostachys mollis.

PubMed

Banchio, Erika; Zygadlo, Julio; Valladares, Graciela R

2005-04-01

Plant tissues may show chemical changes following damage. This possibility was analyzed for Minthostachys mollis, a Lamiaceae native to Central Argentina with medicinal and aromatic uses in the region. Effects of mechanical damage on its two dominant monoterpenes, pulegone and menthone, were analyzed by perforating M. mollis leaves and then assessing essential oil composition at 24, 48, and 120 hr; emission of volatiles was also measured 24 and 48 hr after wounding. Mechanical damage resulted in an increase of pulegone and menthone concentration in M. mollis essential oil during the first 24 hr. These changes did not occur in the adjacent undamaged leaves, suggesting a lack of systemic response. Postwounding changes in the volatiles released from M. mollis damaged leaves were also detected, most noticeably showing an increase in the emission of pulegone. Inducible chemical changes in aromatic plants might be common and widespread, affecting the specific compounds on which commercial exploitation is based.

Essential Oils’ Chemical Characterization and Investigation of Some Biological Activities: A Critical Review

PubMed Central

Dhifi, Wissal; Bellili, Sana; Jazi, Sabrine; Bahloul, Nada; Mnif, Wissem

2016-01-01

This review covers literature data summarizing, on one hand, the chemistry of essential oils and, on the other hand, their most important activities. Essential oils, which are complex mixtures of volatile compounds particularly abundant in aromatic plants, are mainly composed of terpenes biogenerated by the mevalonate pathway. These volatile molecules include monoterpenes (hydrocarbon and oxygenated monoterpens), and also sesquiterpenes (hydrocarbon and oxygenated sesquiterpens). Furthermore, they contain phenolic compounds, which are derived via the shikimate pathway. Thanks to their chemical composition, essential oils possess numerous biological activities (antioxidant, anti-inflammatory, antimicrobial, etc…) of great interest in food and cosmetic industries, as well as in the human health field. PMID:28930135

Effects of Volatile Aromatic Anesthetics on Voltage-Gated Na+ Channels Expressed in Xenopus Oocytes

PubMed Central

Horishita, Takafumi; Eger, Edmond I; Harris, R. Adron

2008-01-01

Background Many inhaled anesthetics inhibit voltage-gated sodium channels at clinically relevant concentrations, and suppression of neurotransmitter release by these agents results, at least partly, from decreased presynaptic sodium channel activity. Volatile aromatic anesthetics can inhibit N-methyl-D-aspartate (NMDA) receptor function and enhance γ-amino butyric acid A (GABAA) receptor function, but these effects depend strongly on the chemical properties of the aromatic ompounds. The present study tested whether diverse aromatic anesthetics consistently inhibit sodium channel function. Methods We studied the effect of eight aromatic anesthetics on Nav1.2 sodium channels with β1 subunits, using whole-cell, two-electrode voltage-clamp techniques in Xenopus oocytes. Results All aromatic anesthetics inhibited INa (sodium currents) at a holding potential which produce half-maximal current (V1/2) (partial depolarization); inhibition was modest with 1,3,5-trifluorobenzene (8 ± 2%), pentafluorobenzene (13 ± 2%), and hexafluorobenzene (13 ± 2%), but greater with benzene (37 ± 2%), fluorobenzene (39 ± 2%), 1,2-difluorobenzene (48 ± 2%), 1,4-difluorobenzene (31 ± 3%), and 1,2,4-trifluorobenzene (33 ± 1%). Such dichotomous effects were noted by others for NMDA and GABAA receptors. Parallel, but much smaller inhibition, was found for INa at a holding potential which produced near maximal current (−90 mV) (VH-90), and hexafluorobenzene caused small (6 ± 1%) potentiation of this current. These changes in sodium channel function were correlated with effectiveness for inhibiting NMDA receptors, with lipid solubility of the compounds, with molecular volume, and with cation-π interactions. Conclusion Aromatic compounds vary in their actions on the kinetics of sodium channel gating and this may underlie their variable inhibition. The range of inhibition produced by MAC concentrations of inhaled anesthetics indicates that sodium channel inhibition may underlie the action of some of these anesthetics but not others. PMID:18931215

Identification of odor volatile compounds and deodorization of Paphia undulata enzymatic hydrolysate

NASA Astrophysics Data System (ADS)

Chen, Deke; Chen, Xin; Chen, Hua; Cai, Bingna; Wan, Peng; Zhu, Xiaolian; Sun, Han; Sun, Huili; Pan, Jianyu

2016-12-01

Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) analysis of volatiles from untreated samples and three deodorized samples (under the optimal conditions) of Paphia undulata enzymatic hydrolysate revealed that the compounds contributing to the distinctive odor were 1-octen-3-ol, n-hexanal, n-heptanal, 2,4-heptadienal, and 2,4-decadienal, whereas n-pentanal, n-octanal, n-octanol, benzaldehyde, 2-ethylfuran and 2-pentylfuran were the main contributors to the aromatic flavor. The deodorizing effects of activated carbon (AC) adsorption, yeast extract (YE) masking and tea polyphenol (TP) treatment on a P. undulata enzymatic hydrolysate were investigated using orthogonal experiments with sensory evaluation as the index. The following optimized deodorization conditions were obtained: AC adsorption (35 mg mL-1, 80°C, 40 min), YE masking (7 mg mL-1, 45°C, 30 min) and TP treatment (0.4 mg mL-1, 40°C, 50 min). AC adsorption effectively removed off-flavor volatile aldehydes and ketones. YE masking modified the odor profile by increasing the relative contents of aromatic compounds and decreasing the relative contents of aldehydes and ketones. The TP treatment was not effective in reducing the odor score, but it significantly reduced the relative content of aldehydes while increasing that of alkanes. It is also notable that TP effectively suppressed trimethylamine (TMA) formation in a P. undulate hydrolysate solution for a period of 72 h.

Diel rhythms in the volatile emission of apple and grape foliage.

PubMed

Giacomuzzi, Valentino; Cappellin, Luca; Nones, Stefano; Khomenko, Iuliia; Biasioli, Franco; Knight, Alan L; Angeli, Sergio

2017-06-01

This study investigated the diel emission of volatile organic compounds (VOCs) from intact apple (Malus x domestica Borkh., cv. Golden Delicious) and grape (Vitis vinifera L., cv. Pinot Noir) foliage. Volatiles were monitored continuously for 48 h by proton transfer reaction - time of flight - mass spectrometry (PTR-ToF-MS). In addition, volatiles were collected by closed-loop-stripping-analysis (CLSA) and characterized by gas chromatography-mass spectrometry (GC-MS) after 1 h and again 24 and 48 h later. Fourteen and ten volatiles were characterized by GC-MS in apple and grape, respectively. The majority of these were terpenes, followed by green leaf volatiles, and aromatic compounds. The PTR-ToF-MS identified 10 additional compounds and established their diel emission rhythms. The most abundant volatiles displaying a diel rhythm included methanol and dimethyl sulfide in both plants, acetone in grape, and mono-, homo- and sesquiterpenes in apple. The majority of volatiles were released from both plants during the photophase; whereas methanol, CO 2 , methyl-butenol and benzeneacetaldehyde were released at significantly higher levels during the scotophase. Acetaldehyde, ethanol, and some green leaf volatiles showed distinct emission bursts in both plants following the daily light switch-off. These new results obtained with a combined analytical approach broaden our understanding of the rhythms of constitutive volatile release from two important horticultural crops. In particular, diel emission of sulfur and nitrogen-containing volatiles are reported here for the first time in these two crops. Copyright © 2017. Published by Elsevier Ltd.

Antennal olfactory responses of adult meadow spittlebug, Philaenus spumarius, to volatile organic compounds (VOCs)

PubMed Central

Ganassi, Sonia; Pistillo, Marco O.; Di Domenico, Carmela; De Cristofaro, Antonio; Di Palma, Antonella Marta

2017-01-01

The meadow spittlebug, Philaenus spumarius L. (Hemiptera, Aphrophoridae) is a commonly found vector of Xylella fastidiosa Wells et al. (1987) strain subspecies pauca associated with the “Olive Quick Decline Syndrome” in Italy. To contribute to the knowledge of the adult P. spumarius chemoreceptivity, electroantennographic (EAG) responses of both sexes to 50 volatile organic compounds (VOCs) including aliphatic aldehydes, alcohols, esters, and ketones, terpenoids, and aromatics were recorded. Measurable EAG responses were elicited by all compounds tested. In both sexes, octanal, 2-octanol, 2-decanone, (E)-2-hexenyl acetate, and vanillin elicited the strongest antennal amplitude within the chemical groups of aliphatic saturated aldehydes, aliphatic alcohols, aliphatic acetates and aromatics, respectively. Male and female EAG responses to sulcatol, (±)linalool, and sulcatone were higher than those to other terpenoinds. In both sexes, the weakest antennal stimulants were phenethyl alcohol and 2-pentanone. Sexual differences in the EAG amplitude were found only for four of test compounds suggesting a general similarity between males and females in antennal sensitivity. The olfactory system of both sexes proved to be sensitive to changes in stimulus concentration, carbon chain length, and compound structure. Compounds with short carbon chain length (C5—C6) elicited lower EAG amplitudes than compounds with higher carbon chain length (C9—C10) in all classes of aliphatic hydrocarbons with different functional groups. The elucidation of the sensitivity profile of P. spumarius to a variety of VOCs provides a basis for future identification of behaviorally-active compounds useful for developing semiochemical-based control strategies of this pest. PMID:29287108

Computational and experimental study of the interactions between ionic liquids and volatile organic compounds.

PubMed

Gao, Tingting; Andino, Jean M; Alvarez-Idaboy, J Raul

2010-09-07

Computational chemistry calculations were performed to investigate the interactions of ionic liquids with different classes of volatile organic compounds (VOCs), including alcohols, aldehydes, ketones, alkanes, alkenes, alkynes and aromatic compounds. At least one VOC was studied to represent each class. Initially, 1-butyl-3-methylimindazolium chloride (abbreviated as C(4)mimCl) was used as the test ionic liquid compound. Calculated interaction lengths between atoms in the ionic liquid and the VOC tested as well as thermodynamic data suggest that C(4)mimCl preferentially interacts with alcohols as compared to other classes of volatile organic compounds. The interactions of methanol with different kinds of ionic liquids, specifically 1-butyl-3-methylimidazolium bromine (C(4)mimBr) and 1-butyl-3-methylimidazolium tetrafluoroborate (C(4)mimBF(4)) were also studied. In comparing C(4)mimCl, C(4)mimBr, and C(4)mimBF(4), the computational results suggest that C(4)mimCl is more likely to interact with methanol. Laboratory experiments were performed to provide further evidence for the interaction between C(4)mimCl and different classes of VOCs. Fourier transform infrared spectroscopy was used to probe the ionic liquid surface before and after exposure to the VOCs that were tested. New spectral features were detected after exposure of C(4)mimCl to various alcohols. The new features are characteristic of the alcohols tested. No new IR features were detected after exposure of the C(4)mimCl to the aldehyde, ketone, alkane, alkene, alkyne or aromatic compounds studied. In addition, after exposing the C(4)mimCl to a multi-component mixture of various classes of compounds (including an alcohol), the only new peaks that were detected were characteristic of the alcohol that was tested. These experimental results demonstrated that C(4)mimCl is selective to alcohols, even in complex mixtures. The findings in this work provide information for future gas-phase alcohol sensor design.

Lactobacillus and Leuconostoc volatilomes in cheese conditions.

PubMed

Pogačić, Tomislav; Maillard, Marie-Bernadette; Leclerc, Aurélie; Hervé, Christophe; Chuat, Victoria; Valence, Florence; Thierry, Anne

2016-03-01

New strains are desirable to diversify flavour of fermented dairy products. The objective of this study was to evaluate the potential of Leuconostoc spp. and Lactobacillus spp. in the production of aroma compounds by metabolic fingerprints of volatiles. Eighteen strains, including five Lactobacillus species (Lactobacillus fermentum, Lactobacillus helveticus, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus sakei) and three Leuconostoc species (Leuconostoc citreum, Leuconostoc lactis, and Leuconostoc mesenteroides) were incubated for 5 weeks in a curd-based slurry medium under conditions mimicking cheese ripening. Populations were enumerated and volatile compounds were analysed by headspace trap gas chromatography-mass spectrometry (GC-MS). A metabolomics approach followed by multivariate statistical analysis was applied for data processing and analysis. In total, 12 alcohols, 10 aldehydes, 7 esters, 11 ketones, 5 acids and 2 sulphur compounds were identified. Very large differences in concentration of volatile compounds between the highest producing strains and the control medium were observed in particular for diacetyl, 2-butanol, ethyl acetate, 3-methylbutanol, 3-methylbutanoic acid and 2-methylbutanoic acid. Some of the characterized strains demonstrated an interesting aromatizing potential to be used as adjunct culture.

Participant-Based Monitoring of Indoor and Outdoor Nitrogen Dioxide, Volatile Organic Compounds, and Polycyclic Aromatic Hydrocarbons among MICA-Air Households

EPA Science Inventory

The Mechanistic Indicators of Childhood Asthma (MICA) study in Detroit, Michigan introduced a participant-based approach to reduce the resource burden associated with collection of indoor and outdoor residential air sampling data. A subset of participants designated as MICA-Air c...

RELATIVE CONGENER SCALING OF POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS TO ESTIMATE BUILDING FIRE CONTRIBUTIONS IN AIR, SURFACE WIPES, AND DUST SAMPLES

EPA Science Inventory

EPA collected ambient air samples in lower Manhattan for about nine months following the September 11, 2001 (9/11) World Trade Center (WTC) attacks. Measurements were made of a host of airborne contaminants including volatile organic compounds (VOCs), polycyclic aromatic hydroca...

Toxic Remediation System And Method

DOEpatents

Matthews, Stephen M.; Schonberg, Russell G.; Fadness, David R.

1996-07-23

What is disclosed is a novel toxic waste remediation system designed to provide on-site destruction of a wide variety of hazardous organic volatile hydrocarbons, including but not limited to halogenated and aromatic hydrocarbons in the vapor phase. This invention utilizes a detoxification plenum and radiation treatment which transforms hazardous organic compounds into non-hazardous substances.

Indole is an essential herbivore-induced volatile priming signal in maize

PubMed Central

Erb, Matthias; Veyrat, Nathalie; Robert, Christelle A. M.; Xu, Hao; Frey, Monika; Ton, Jurriaan; Turlings, Ted C. J.

2015-01-01

Herbivore-induced volatile organic compounds prime non-attacked plant tissues to respond more strongly to subsequent attacks. However, the key volatiles that trigger this primed state remain largely unidentified. In maize, the release of the aromatic compound indole is herbivore-specific and occurs earlier than other induced responses. We therefore hypothesized that indole may be involved in airborne priming. Using indole-deficient mutants and synthetic indole dispensers, we show that herbivore-induced indole enhances the induction of defensive volatiles in neighbouring maize plants in a species-specific manner. Furthermore, the release of indole is essential for priming of mono- and homoterpenes in systemic leaves of attacked plants. Indole exposure markedly increases the herbivore-induced production of the stress hormones jasmonate-isoleucine conjugate and abscisic acid, which represents a likely mechanism for indole-dependent priming. These results demonstrate that indole functions as a rapid and potent aerial priming agent that prepares systemic tissues and neighbouring plants for incoming attacks. PMID:25683900

Climatic factors directly impact the volatile organic compound fingerprint in green Arabica coffee bean as well as coffee beverage quality.

PubMed

Bertrand, B; Boulanger, R; Dussert, S; Ribeyre, F; Berthiot, L; Descroix, F; Joët, T

2012-12-15

Coffee grown at high elevations fetches a better price than that grown in lowland regions. This study was aimed at determining whether climatic conditions during bean development affected sensory perception of the coffee beverage and combinations of volatile compounds in green coffee. Green coffee samples from 16 plots representative of the broad range of climatic variations in Réunion Island were compared by sensory analysis. Volatiles were extracted by solid phase micro-extraction and the volatile compounds were analysed by GC-MS. The results revealed that, among the climatic factors, the mean air temperature during seed development greatly influenced the sensory profile. Positive quality attributes such as acidity, fruity character and flavour quality were correlated and typical of coffees produced at cool climates. Two volatile compounds (ethanal and acetone) were identified as indicators of these cool temperatures. Among detected volatiles, most of the alcohols, aldehydes, hydrocarbons and ketones appeared to be positively linked to elevated temperatures and high solar radiation, while the sensory profiles displayed major defects (i.e. green, earthy flavour). Two alcohols (butan-1,3-diol and butan-2,3-diol) were closely correlated with a reduction in aromatic quality, acidity and an increase in earthy and green flavours. We assumed that high temperatures induce accumulation of these compounds in green coffee, and would be detected as off-flavours, even after roasting. Climate change, which generally involves a substantial increase in average temperatures in mountainous tropical regions, could be expected to have a negative impact on coffee quality. Copyright © 2012 Elsevier Ltd. All rights reserved.

Characterization of aromatic properties of old-style cheese starters.

PubMed

Lacroix, N; St-Gelais, D; Champagne, C P; Fortin, J; Vuillemard, J-C

2010-08-01

Old-style cheese starters were evaluated to determine their ability to produce cheese aroma compounds. Detailed analyses of the aroma-producing potential of 13 old-style starter cultures were undertaken. The proteolytic profile of the starters was established by an accelerated ripening study using a model cheese slurry and compared with those of a commercial aromatic starter and commercial Cheddar cheeses. To evaluate the aromatic potential of the starter cultures, quantification of free amino acids liberated and volatile compounds after 15 d of ripening at 30 degrees C as well as sensory analysis were carried out. Results showed that proteolysis patterns of all 13 starter cultures in the curd model were comparable to those of commercial Cheddar cheeses. All tested cultures demonstrated the ability to produce high amounts of amino acids recognized as precursors of aroma compounds. Several differences were observed between the starters and commercial Cheddar cheeses regarding some amino acids such as glutamate, leucine, phenylalanine, proline, and ornithine, reflecting the various enzymatic systems present in the starters. Starters Bt (control) and ULAAC-E exhibited various significant differences regarding their free amino acid profiles, as confirmed by sensory analysis. In addition, identification of volatile compounds confirmed the presence of several key molecules related to aroma, such as 3-methylbutanal and diacetyl. Besides the aroma-producing aspect, 2 starters (ULAAC-A and ULAAC-H) seem to possess an important ability to generate large amounts of gamma-aminobutyric acid, which contributed up to 15% of the total amino acids present in the model curd after 15 d ripening. gamma-Aminobutyric acid is an amine well-known for its antihypertensive and calming effects. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The impact of the fuel chemical composition on volatile organic compounds emitted by an in-service aircraft gas turbine engine

NASA Astrophysics Data System (ADS)

Setyan, A.; Kuo, Y. Y.; Brem, B.; Durdina, L.; Gerecke, A. C.; Heeb, N. V.; Haag, R.; Wang, J.

2017-12-01

Aircraft emissions received increased attention recently because of the steady growth of aviation transport in the last decades. Aircraft engines substantially contribute to emissions of particulate matter and gaseous pollutants in the upper and lower troposphere. Among all the pollutants emitted by aircrafts, volatile organic compounds (VOCs) are particularly important because they are mainly emitted at ground level, posing a serious health risk for people living or working near airports. A series of measurements was performed at the aircraft engine testing facility of SR Technics (Zürich airport, Switzerland). Exhausts from an in-service turbofan engine were sampled at the engine exit plane by a multi-point sampling probe. A wide range of instruments was connected to the common sampling line to determine physico-chemical characteristics of non-volatile particulate matter and gaseous pollutants. Conventional Jet A-1 fuel was used as the base fuel, and measurements were performed with the base fuel doped with two different mixtures of aromatic compounds (Solvesso 150 and naphthalene-depleted Solvesso 150) and an alternative fuel (hydro-processed esters and fatty acids [HEFA] jet fuel). During this presentation, we will show results obtained for VOCs. These compounds were sampled with 3 different adsorbing cartridges, and analyzed by thermal desorption gas chromatography/mass spectrometry (TD-GC/MS, for Tenax TA and Carboxen 569) and by ultra-performance liquid chromatography/ mass spectrometry (UPLC/MS, for DNPH). The total VOC concentration was also measured with a flame ionization detector (FID). In addition, fuel samples were also analyzed by GC/MS, and their chemical compositions were compared to the VOCs emitted via engine exhaust. Total VOCs concentrations were highest at ground idle (>200 ppm C at 4-7% thrust), and substantially lower at high thrust (<3 ppm C during take-off, 100% thrust). Fuel samples were dominated by alkanes, whereas VOCs emitted by the aircraft engine were mainly constituted of alkanes, oxygenated compounds, and aromatics. More than 50 % of the compounds identified in the exhaust were not present in the fuel, and thus were formed during combustion. The impact of the fuel doping with aromatics and the alternative fuel on VOCs emitted by the engine will also be discussed.

Hydrocarbon emissions speciation in diesel and biodiesel exhausts

NASA Astrophysics Data System (ADS)

Payri, Francisco; Bermúdez, Vicente R.; Tormos, Bernardo; Linares, Waldemar G.

Diesel engine emissions are composed of a long list of organic compounds, ranging from C 2 to C 12+, and coming from the hydrocarbons partially oxidized in combustion or produced by pyrolisis. Many of these are considered as ozone precursors in the atmosphere, since they can interact with nitrogen oxides to produce ozone under atmospheric conditions in the presence of sunlight. In addition to problematic ozone production, Brookes, P., and Duncan, M. [1971. Carcinogenic hydrocarbons and human cells in culture. Nature.] and Heywood, J. [1988. Internal Combustion Engine Fundamentals.Mc Graw-Hill, ISBN 0-07-1000499-8.] determined that the polycyclic aromatic hydrocarbons present in exhaust gases are dangerous to human health, being highly carcinogenic. The aim of this study was to identify by means of gas chromatography the amount of each hydrocarbon species present in the exhaust gases of diesel engines operating with different biodiesel blends. The levels of reactive and non-reactive hydrocarbons present in diesel engine exhaust gases powered by different biodiesel fuel blends were also analyzed. Detailed speciation revealed a drastic change in the nature and quantity of semi-volatile compounds when biodiesel fuels are employed, the most affected being the aromatic compounds. Both aromatic and oxygenated aromatic compounds were found in biodiesel exhaust. Finally, the conservation of species for off-side analysis and the possible influence of engine operating conditions on the chemical characterization of the semi-volatile compound phase are discussed. The use of oxygenated fuel blends shows a reduction in the Engine-Out emissions of total hydrocarbons. But the potential of the hydrocarbon emissions is more dependent on the compositions of these hydrocarbons in the Engine-Out, to the quantity; a large percent of hydrocarbons existing in the exhaust, when biodiesel blends are used, are partially burned hydrocarbons, and are interesting as they have the maximum reactivity, but with the use of pure biodiesel and diesel, the most hydrocarbons are from unburned fuel and they have a less reactivity. The best composition in the fuel, for the control of the hydrocarbon emissions reactivity, needs to be a fuel with high-saturated fatty acid content.

Volatiles from the fungal microbiome of the marine sponge Callyspongia cf. flammea.

PubMed

Barra, Lena; Barac, Paul; König, Gabriele M; Crüsemann, Max; Dickschat, Jeroen S

2017-09-13

The volatiles emitted by five fungal strains previously isolated from the marine sponge Callyspongia cf. flammea were captured with a closed-loop stripping apparatus (CLSA) and analyzed by GC-MS. Besides several widespread compounds, a series of metabolites with interesting bioactivities were found, including the quorum sensing inhibitor protoanemonin, the fungal phytotoxin 3,4-dimethylpentan-4-olide, and the insect attractant 1,2,4-trimethoxybenzene. In addition, the aromatic polyketides isotorquatone and chartabomone that are both known from Eucalyptus and a new O-desmethyl derivative were identified. The biosynthesis of isotorquatone was studied by feeding experiments with isotopically labeled precursors and its absolute configuration was determined by enantioselective synthesis of a reference compound. Bioactivity testings showed algicidal activity for some of the identified compounds, suggesting a potential ecological function in sponge defence.

HS/GC-MS analyzed chemical composition of the aroma of fruiting bodies of two species of genus Lentinus (Higher Basidiomycetes).

PubMed

Mata, Gerardo; Valdez, Karina; Mendoza, Remedios; Trigos, Ángel

2014-01-01

The chemical composition of the aroma of fresh fruiting bodies of the cultivated mushroom Lentinus boryanus is described here and compared with medicinal shiitake mushroom L. edodes. Volatile compounds were analyzed through headspace sampling coupled with gas chromatography-mass spectrometry. The mushrooms under study were grown on different substrates based on barley straw, sugarcane bagasse, oak wood sawdust, and beech leaf litter. It was determined that L. boryanus as well as L. edodes contain an abundant amount of a volatile compound identified as 3-octanone with a sweet fruity aroma. On the other hand, only L. boryanus produced 3-octanol a characteristic aroma of cod liver oil. In total, 10 aromatic compounds were identified, some of which were obtained exclusively in one species or substrate.

Aroma characterization based on aromatic series analysis in table grapes

PubMed Central

Wu, Yusen; Duan, Shuyan; Zhao, Liping; Gao, Zhen; Luo, Meng; Song, Shiren; Xu, Wenping; Zhang, Caixi; Ma, Chao; Wang, Shiping

2016-01-01

Aroma is an important part of quality in table grape, but the key aroma compounds and the aroma series of table grapes remains unknown. In this paper, we identified 67 aroma compounds in 20 table grape cultivars; 20 in pulp and 23 in skin were active compounds. C6 compounds were the basic background volatiles, but the aroma contents of pulp juice and skin depended mainly on the levels of esters and terpenes, respectively. Most obviously, ‘Kyoho’ grapevine series showed high contents of esters in pulp, while Muscat/floral cultivars showed abundant monoterpenes in skin. For the aroma series, table grapes were characterized mainly by herbaceous, floral, balsamic, sweet and fruity series. The simple and visualizable aroma profiles were established using aroma fingerprints based on the aromatic series. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) showed that the aroma profiles of pulp juice, skin and whole berries could be classified into 5, 3, and 5 groups, respectively. Combined with sensory evaluation, we could conclude that fatty and balsamic series were the preferred aromatic series, and the contents of their contributors (β-ionone and octanal) may be useful as indicators for the improvement of breeding and cultivation measures for table grapes. PMID:27487935

Distribution of volatile organic compounds over a semiconductor Industrial Park in Taiwan.

PubMed

Chiu, Kong-Hwa; Wu, Ben-Zen; Chang, Chih-Chung; Sree, Usha; Lo, Jiunn-Guang

2005-02-15

This study examined volatile organic compounds (VOC) concentration in ambient air collected during the years 2000--2003 at several different locations of Hsinchu Science-based Industrial Park (HSIP) in Taiwan. A canister automated GC-MS system analyzed the volatile organics in ambient air grasp samples according to T0-15 method. Oxygenated volatiles were the most abundant VOC detected in HSIP followed by aromatics that are commonly used as solvents in the semiconductor industries. The major components measured in the ambient air are 2-propanol (29-135 ppbv), acetone (12-164 ppbv), benzene (0.7-1.7 ppbv), and toluene (13-20 ppbv). At some of the sampling locations, odorous compounds such as carbon disulfide and dimethyl sulfide levels exceed threshold values. The estimated toluene/benzene ratio is very high at most of the sites. However, the total amount of VOC is reduced over the years from 2000 to 2003 due to strict implementation on use and discharge of solvents in industries. There exists no definite seasonal pattern for sporadic occurrence of high levels of some of the volatile organics. Stagnant weather conditions with low wind speeds aid accumulation of toxic species at ground level. The results entail that hi-tech semiconductor industries are still a potential source for harmful organic substances to surrounding microenvironment.

Flavor characteristics of seven grades of black tea produced in Turkey.

PubMed

Alasalvar, Cesarettin; Topal, Bahar; Serpen, Arda; Bahar, Banu; Pelvan, Ebru; Gökmen, Vural

2012-06-27

Seven grades of black tea [high-quality black tea (grades 1-3) and low-quality black tea (grades 4-7)], processed by ÇAYKUR Tea Processing Plant (Rize, Turkey), were compared for their differences in descriptive sensory analysis (DSA), aroma-active compounds (volatile compounds), and taste-active compounds (sugar, organic acid, and free amino acid compositions). Ten flavor attributes such as 'after taste', 'astringency', 'bitter', 'caramel-like', 'floral/sweet', 'green/grassy', 'hay-like', 'malty', 'roasty', and 'seaweed' were identified. Intensities for a number of flavor attributes ('after taste', 'caramel-like', 'malty', and 'seaweed') were not significantly different (p > 0.05) among seven grades of black tea. A total of 57 compounds in seven grades of black tea (14 aldehydes, eight alcohols, eight ketones, two esters, four aromatic hydrocarbons, five aliphatic hydrocarbons, nine terpenes, two pyrazines, one furan, two acids, and two miscellaneous compounds) were tentatively identified. Of these, aldeyhdes comprised more than 50% to the total volatile compounds identified. In general, high-grade quality tea had more volatiles than low-grade quality tea. With respect to taste-active compounds, five sugars, six organic acids, and 18 free amino acids were positively identified in seven grades of black tea, of which fructose, tannic acid, and theanine predominated, respectively. Some variations (p < 0.05), albeit to different extents, were observed among volatile compounds, sugars, organic acids, and free amino acids in seven grades of black tea. The present study suggests that a certain flavor attributes correlate well with taste- and aroma-active compounds. High- and low-quality black teas should not be distinguished solely on the basis of their DSA and taste- and aroma-active compounds. The combination of taste-active compounds together with aroma-active compounds renders combination effects that provide the characteristic flavor of each grade of black tea.

Characterization and treatment of dissolved organic matter from oilfield produced waters.

PubMed

Wang, Xiaojing; Goual, Lamia; Colberg, Patricia J S

2012-05-30

Dissolved organic matter (DOM) has been studied intensively in streams, lakes and oceans due to its role in the global carbon cycle and because it is a precursor of carcinogenic disinfection by-products in drinking water; however, relatively little research has been conducted on DOM in oilfield produced waters. In this study, recovery of DOM from two oilfield produced waters was relatively low (~34%), possibly due to the presence of high concentrations of volatile organic compounds (VOCs). A van Krevelen diagram of the extracted DOM suggested the presence of high concentrations of lipids, lignin, and proteins, but low concentrations of condensed hydrocarbons. Most of the compounds in the oilfield DOM contained sulfur in their structures. Fourier transform infrared (FTIR) spectra indicated the presence of methyl groups, amides, carboxylic acids, and aromatic compounds, which is in agreement with results of Fourier transform ion cyclotron resonance (FT-ICR) analysis. Qualitatively, DOM in oilfield produced waters is similar to that reported in oceans and freshwater, except that it contains much more sulfur and is less aromatic. Treatment studies conducted in a fluidized bed reactor suggested that volatilization of organics may be a more important mechanism of DOM removal than microbial degradation. Copyright © 2012 Elsevier B.V. All rights reserved.

Emissions of volatile organic compounds from maize residue open burning in the northern region of Thailand

NASA Astrophysics Data System (ADS)

Sirithian, Duanpen; Thepanondh, Sarawut; Sattler, Melanie L.; Laowagul, Wanna

2018-03-01

Emission factors for speciated volatile organic compounds (VOCs) from maize residue burning were determined in this study based on chamber experiments. Thirty-six VOC species were identified by Gas Chromatography/Mass Spectrometer (GC/MS). They were classified into six groups, including alkanes, alkenes, oxygenated VOCs, halogenated VOCs, aromatics and other. The emission factor for total VOCs was estimated as about 148 mg kg-1 dry mass burned. About 68.4% of the compounds were aromatics. Field samplings of maize residues were conducted to acquire the information of fuel characteristics including fuel loading, fraction of maize residues that were actually burned as well as proximate and elemental analysis of maize residues. The emission factors were then applied to estimate speciated VOC emissions from maize residue open burning at the provincial level in the upper-northern region of Thailand for the year 2014. Total burned area of maize covered an area of about 500,000 ha which was about 4.7% of the total area of upper-northern region of the country. It was found that total VOC emissions released during the burning season (January-April) was about 79.4 tons. Ethylbenzene, m,p-xylene, 1,2,4-trimethylbenzene, acetaldehyde and o-xylene were the major contributors, accounting for more than 65% of total speciated VOC emissions.

Constituents of volatile organic compounds of evaporating essential oil

NASA Astrophysics Data System (ADS)

Chiu, Hua-Hsien; Chiang, Hsiu-Mei; Lo, Cho-Ching; Chen, Ching-Yen; Chiang, Hung-Lung

2009-12-01

Essential oils containing aromatic compounds can affect air quality when used indoors. Five typical and popular essential oils—rose, lemon, rosemary, tea tree and lavender—were investigated in terms of composition, thermal characteristics, volatile organic compound (VOC) constituents, and emission factors. The activation energy was 6.3-8.6 kcal mol -1, the reaction order was in the range of 0.6-0.8, and the frequency factor was 0.01-0.24 min -1. Toluene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, n-undecane, p-diethylbenzene and m-diethylbenzene were the predominant VOCs of evaporating gas of essential oils at 40 °C. In addition, n-undecane, p-diethylbenzene, 1,2,4-trimethylbenzene, m-diethylbenzene, and 1,2,3-trimethylbenzene revealed high emission factors during the thermogravimetric (TG) analysis procedures. The sequence of the emission factors of 52 VOCs (137-173 mg g -1) was rose ≈ rosemary > tea tree ≈ lemon ≈ lavender. The VOC group fraction of the emission factor of aromatics was 62-78%, paraffins were 21-37% and olefins were less than 1.5% during the TG process. Some unhealthy VOCs such as benzene and toluene were measured at low temperature; they reveal the potential effect on indoor air quality and human health.

[Study on composition, antibiotic activity and antioxidant activity of volatile oils from uyghur medicine Althaea rosea].

PubMed

Munira, Abudukeremu; Muheta'er, Tu'erhong; Resalat, Yimin; Xia, Na

2015-04-01

Althaea rosea is a type of mallow plant. Its dry flowers are one of common herb in Uyghur medicines and recorded to have several efficacies such as external application for detumescence, moistening lung and arresting cough, sweating and relieving asthma, diminishing swelling and promoting eruption, soothing the nerves and strengthening heart. However, there are only fewer studies on effective components of A. rosea and no literature about its volatile oil and pharmacological activity. In this paper, the volatile oil of A. rosea was obtained by using the chemical distillation and extraction method. The individual chemical components were separated from the volatile oil and identified by the Gas Chromatograph-Mass Spectrometer technique (GC-MS). The antioxidant activity against free radicals was detected by the'ultraviolet and visible spectrophotometer method. The antibiotic activity was detected by the filter paper diffusion method. The experimental results showed nearly 70 compounds in the volatile oil, with complex chemical components. With a low content, most of the compounds were aromatic and aliphatic compounds and their derivatives. A. rosea had a better antibiotic activity for common microorganisms, with a wide antibacterial spectrum. According to the results, the volatile oil of A. rosea will have a good application value in medicine, food and cosmetic industries, which provided a scientific basis for the development of natural A. rosea resources.

Characteristics of Milk Fermented by Streptococcus thermophilus MGA45-4 and the Profiles of Associated Volatile Compounds during Fermentation and Storage.

PubMed

Dan, Tong; Jin, Rulin; Ren, Weiyi; Li, Ting; Chen, Haiyan; Sun, Tiansong

2018-04-11

The lactic acid bacterium Streptococcus thermophilus is a major starter culture for the production of dairy products. In this study, the physiochemical characteristics of milk fermented by the MGA45-4 isolate of S. thermophilus were analyzed. Our data indicate that milk fermented using S. thermophilus MGA45-4 maintained a high viable cell count (8.86 log10 colony-forming units/mL), and a relatively high pH (4.4), viscosity (834.33 mPa·s), and water holding capacity (40.85%) during 14 days of storage. By analyzing the volatile compound profile using solid-phase microextraction and gas chromatography/mass spectrometry, we identified 73 volatile compounds in the fermented milk product, including five carboxylic acids, 21 aldehydes, 13 ketones, 16 alcohols, five esters, and 13 aromatic carbohydrates. According to the odor activity values, 11 of these volatile compounds were found to play a key role in producing the characteristic flavor of fermented milk, particularly octanal, nonanal, hexanal, 2,3-butanedione, and 1-octen-3-ol, which had the highest odor activity values among all compounds analyzed. These findings thus provide more insights in the chemical/molecular characteristics of milk fermented using S. thermophilus , which may provide a basis for improving dairy product flavor/odor during the process of fermentation and storage.

Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants.

PubMed

Jumpponen, M; Rönkkömäki, H; Pasanen, P; Laitinen, J

2013-01-01

The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

Characteristic analysis for odor gas emitted from food waste anaerobic fermentation in the pretreatment workshop.

PubMed

Di, Yanqiang; Liu, Jiemin; Liu, Jianguo; Liui, Siyuan; Yan, Luchun

2013-10-01

Gas chromatography-mass spectrometry, olfactometry, and other related methods were applied for the qualitative and quantitative analysis of the characteristics of odorous gases in the pretreatment workshop. The composition of odorous gases emitted from municipal food waste was also investigated in this study. The results showed that the tested gases are mainly composed of aromatic gases, which account for 49% of the total volatile organic compounds (VOC) concentrations. The nitrogenous compounds comprise 15% of the total concentration and the other gases comprise the remaining 36%. The level of odor concentration ranged from 2523 odor units (OU) m(-3) to 3577 OU m(-3). The variation of the total chemical composition ranged from 19,725 microg m(-3) to 24,184 microg m(-3). Among the selected four sampling points, the discharge outlet was detected to have the highest concentration in terms of odor, total chemical, sulfur compounds, and aromatics. The correlation analysis showed that the odor concentrations were evidently related to the total chemical composition, sulfur compounds, and aromatics (P < 0.05, n = 5). The odor activity value analysis identified the top three compounds, hydrogen sulfide (91.8), ethyl sulfide (35.8), and trimethylamine (70.6), which contribute to air pollution complaint of waste materials.

REAL TIME, ON-LINE CHARACTERIZATION OF DIESEL GENERATOR AIR TOXIC EMISSIONS BY RESONANCE ENHANCED MULTI-PHOTON IONIZATION TIME OF FLIGHT MASS SPECTROMETRY

EPA Science Inventory

The laser based resonance, enhanced multi-photon ionization time-of-flight mass spectrometry (REMPI-TOFMS) technique has been applied to the exhaust gas stream of a diesel generator to measure, in real time, concentration levels of aromatic air toxics. Volatile organic compounds ...

Impact of aromatics and monoterpenes on simulated tropospheric ozone and total OH reactivity

NASA Astrophysics Data System (ADS)

Porter, William C.; Safieddine, Sarah A.; Heald, Colette L.

2017-11-01

The accurate representation of volatile organic compounds (VOCs) in models is an important step towards the goal of understanding and predicting many changes in atmospheric constituents relevant to climate change and human health. While isoprene is the most abundant non-methane VOC, many other compounds play a large role in governing pollutant formation and the overall oxidative capacity of the atmosphere. We quantify the impacts of aromatics and monoterpenes, two classes of VOC not included in the standard gas-phase chemistry of the chemical transport model GEOS-Chem, on atmospheric composition. We find that including these compounds increases mean total summer OH reactivity by an average of 11% over the United States, Europe, and Asia. This increased reactivity results in higher simulated levels of O3, raising maximum daily 8-h average O3 in the summer by up to 14 ppb at some NOx-saturated locations.

Proton-transfer-reaction mass spectrometry for the study of the production of volatile compounds by bakery yeast starters.

PubMed

Makhoul, Salim; Romano, Andrea; Cappellin, Luca; Spano, Giuseppe; Capozzi, Vittorio; Benozzi, Elisabetta; Märk, Tilmann D; Aprea, Eugenio; Gasperi, Flavia; El-Nakat, Hanna; Guzzo, Jean; Biasioli, Franco

2014-09-01

The aromatic impact of bakery yeast starters is currently receiving considerable attention. The flavor characteristics of the dough and the finished products are usually evaluated by gas chromatography and sensory analysis. The limit of both techniques resides in their low-throughput character. In the present work, proton-transfer-reaction mass spectrometry (PTR-MS), coupled to a time-of-flight mass analyzer, was employed, for the first time, to measure the volatile fractions of dough and bread, and to monitor Saccharomyces cerevisiae volatile production in a fermented food matrix. Leavening was performed on small-scale (1 g) dough samples inoculated with different commercial yeast strains. The leavened doughs were then baked, and volatile profiles were determined during leavening and after baking. The experimental setup included a multifunctional autosampler, which permitted the follow-up of the leavening process on a small scale with a typical throughput of 500 distinct data points in 16 h. The system allowed to pinpoint differences between starter yeast strains in terms of volatile emission kinetics, with repercussions on the final product (i.e. the corresponding micro-loaves). This work demonstrates the applicability of PTR-MS for the study of volatile organic compound production during bread-making, for the automated and online real-time monitoring of the leavening process, and for the characterization and selection of bakery yeast starters in view of their production of volatile compounds. Copyright © 2014 John Wiley & Sons, Ltd.

Condensed milk storage and evaporation affect the flavor of nonfat dry milk.

PubMed

Park, Curtis W; Drake, MaryAnne

2016-12-01

Unit operations in nonfat dry milk (NFDM) manufacture influence sensory properties, and consequently, its use and acceptance in ingredient applications. Condensed skim milk may be stored at refrigeration temperatures for extended periods before spray drying due to shipping or lack of drying capacity. Currently, NFDM processors have 2 options for milk concentration up to 30% solids: evaporation (E) or reverse osmosis (RO). The objective of this study was to determine the effect of condensed milk storage and milk concentration method (E vs. RO) on the flavor of NFDM and investigate mechanisms behind flavor differences. For experiment 1, skim milk was pasteurized and concentrated to 30% solids by E or RO and then either stored for 24h at 4°C or concentrated to 50% solids by E and spray dried immediately. To investigate mechanisms behind the results from experiment 1, experiment 2 was constructed. In experiment 2, pasteurized skim milk was subjected to 1 of 4 treatments: control (no E), heated in the evaporator without vacuum, E concentration to 30% solids, or E concentration to 40% solids. The milks were then diluted to the same solids content and evaluated. Volatile compounds were also measured during concentration in the vapor separator of the evaporator. Sensory properties were evaluated by descriptive sensory analysis and instrumental volatile compound analysis was conducted to evaluate volatile compounds. Interaction effects between storage and method of concentration were investigated. In experiment 1, E decreased sweet aromatic flavor and many characteristic milk flavor compounds and increased cardboard and cooked flavors in NFDM compared with RO. Liquid storage increased cardboard flavor and hexanal and octanal and decreased sweet aromatic flavors and vanillin concentration. Results from experiment 2 indicated that the characteristic milk flavors and their associated volatile compounds were removed by the vapor separator in the evaporator due to the heat and vacuum applied during concentration. These results demonstrate that off-flavors are significantly reduced when RO is used in place of E and storage of condensed milk is avoided. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Secondary organic aerosol formation through cloud processing of aromatic VOCs

NASA Astrophysics Data System (ADS)

Herckes, P.; Hutchings, J. W.; Ervens, B.

2010-12-01

Field observations have shown substantial concentrations (20-5,500 ng L-1) of aromatic volatile organic compounds (VOC) in cloud droplets. The potential generation of secondary organic aerosol mass through the processing of these anthropogenic VOCs was investigated through laboratory and modeling studies. Under simulated atmospheric laboratory conditions, in idealized solutions, benzene, toluene, ethylbenzene, and xylene (BTEX) degraded quickly in the aqueous phase. The degradation process yielded less volatile products which would contribute to new aerosol mass upon cloud evaporation. However, when realistic cloud solutions containing natural organic matter were used in the experiments, the reaction rates decreased with increasing organic carbon content. Kinetic data derived from these experiments were used as input to a multiphase box model in order to evaluate the secondary organic aerosol (SOA) mass formation potential of cloud processing of BTEX. Model results will be presented that quantify the SOA amounts from these aqueous phase pathways. The efficiency of this multiphase SOA source will be compared to SOA yields from the same aromatics as treated in traditional SOA models that are restricted to gas phase oxidation and subsequent condensation on particles.

Volatile compounds and odor traits of dry-cured ham (Prosciutto crudo) irradiated by electron beam and gamma rays

NASA Astrophysics Data System (ADS)

Kong, Qiulian; Yan, Weiqiang; Yue, Ling; Chen, Zhijun; Wang, Haihong; Qi, Wenyuan; He, Xiaohua

2017-01-01

Prosciutto crudo samples were irradiated at 0, 3 and 6 kGy by gamma rays (GR) and electron beam (EB), respectively. The odor scores and volatile compounds were examined after 7 days storage at 4 °C. Volatile compounds from samples without and with irradiation at 6 kGy were analyzed by GC-MS. Fifty-nine compounds were identified, including terpenes, aldehydes, alcohols, ketones, alkanes, esters, aromatic hydrocarbons and acids. Both GR and EB irradiation resulted in formation of (Z)-7-Hexadecenal, cis-9-hexadecenal, tetradecane, E-9-tetradecen-1-ol formate, and losing of hexadecamethyl-heptasiloxane and decanoic acid-ethyl ester in hams. However, GR irradiation caused additional changes, such as formation of undecane and phthalic acid-2-cyclohexylethyl butyl ester, significantly higher level of 1-pentadecene, and losing of (E, E)-2,4-decadienal and octadecane. EB was shown to be better in maintaining ham's original odor than GR. Our results suggest that EB irradiation is a promising method for treatment of ready to eat hams as it exerts much less negative effect on the flavor of hams compared to GR irradiation.

Influence of processing on the volatile profile of strawberry spreads made with isomaltulose.

PubMed

Peinado, I; Rosa, E; Heredia, A; Escriche, I; Andrés, A

2013-05-01

A new strawberry spread formulated with fructose and isomaltulose (replacing sucrose partially or totally) and a high percentage of fruit was developed in line with the new trend of healthier products. This work studies the influence of some process variables (percentage of sugar, pectin and citric acid, and time of thermal treatment) on the volatile profile of these spreads with different formulations. The ripeness of the raw strawberries influences the concentrations of some of the compounds in the spreads, such as isobutyl acetate, butyl butyrate, 3-hexen-1-yl acetate or propan-2-ol. The process conditions have an important effect on the volatile profiles. Most of the esters and alcohols decreased whereas 13 new compounds appear, mostly furans (furfural, 2-acetylfurane, 5-methyl furfural, mesifurane) and aldehydes (octanal, nonanal, decanal and benzaldeyhde). In general, the spreads formulated with sucrose-isomaltulose that contained higher levels of pectin and citric acid gave better results in the preservation of the original aromatic compounds in raw strawberries. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of ultrasound-assisted freezing on the physico-chemical properties and volatile compounds of red radish.

PubMed

Xu, Bao-Guo; Zhang, Min; Bhandari, Bhesh; Cheng, Xin-Feng; Islam, Md Nahidul

2015-11-01

Power ultrasound, which can enhance nucleation rate and crystal growth rate, can also affect the physico-chemical properties of immersion frozen products. In this study, the influence of slow freezing (SF), immersion freezing (IF) and ultrasound-assisted freezing (UAF) on physico-chemical properties and volatile compounds of red radish was investigated. Results showed that ultrasound application significantly improved the freezing rate; the freezing time of ultrasound application at 0.26 W/cm(2) was shorten by 14% and 90%, compared to IF and SF, respectively. UAF products showed significant (p<0.05) reduction in drip loss and phytonutrients (anthocyanins, vitamin C and phenolics) loss. Compared to SF products, IF and UAF products showed better textural preservation and higher calcium content. The radish tissues exhibited better cellular structures under ultrasonic power intensities of 0.17 and 0.26 W/cm(2) with less cell separation and disruption. Volatile compound data revealed that radish aromatic profile was also affected in the freezing process. Copyright © 2015 Elsevier B.V. All rights reserved.

Volatile and key odourant compounds of Turkish Berberis crataegina fruit using GC-MS-Olfactometry.

PubMed

Sonmezdag, Ahmet Salih; Kelebek, Hasim; Selli, Serkan

2018-04-01

This research was conducted to identify the aroma and aroma-active compounds of Berberis crataegina for the first time. Volatile profile of B. crataegina was obtained using the purge and trap extraction method with dichloromethane. Gas chromatography was coupled to mass spectrometry (GC-MS) allowed the quantitative and qualitative detection of 22 compounds in the sample. Aldehydes were the main chemical group in the sample and followed by aromatic alcohols and lactone. Aroma extract dilution analysis was implemented for the specification of key odourants of B. crataegina. In total, eight key odourants were detected in the extract of the sample, using GC-MS-Olfactometry and aldehydes were the leading chemical group. The key odourants, found to be contributing to the overall aroma in B. crataegina, were nonanal (FD = 1024; green, flowery), hexanal (FD = 512; green) and linalool (FD = 256; flowery, rose) because of high FD factors.

The evolution of floral scent and insect chemical communication.

PubMed

Schiestl, Florian P

2010-05-01

Plants have evolved a range of strategies to manipulate the behaviour of their insect partners. One powerful strategy is to produce signals that already have a role in the animals' own communication systems. To investigate to what extent the evolution of floral scents is correlated with chemical communication in insects, I analyse the occurrence, commonness, and evolutionary patterns of the 71 most common 'floral' volatile organic compounds (VOCs) in 96 plant families and 87 insect families. I found an overlap of 87% in VOCs produced by plants and insects. 'Floral' monoterpenes showed strong positive correlation in commonness between plants (both gymnosperms and angiosperms) and herbivores, whereas the commonness of 'floral' aromatics was positively correlated between angiosperms and both pollinators and herbivores. According to a multivariate regression analysis the commonness of 'floral' aromatics was best explained by their commonness in pollinators, whereas monoterpenes were best explained by herbivores. Among pollinator orders, aromatics were significantly more common in Lepidoptera than in Hymenoptera, whereas monoterpenes showed no difference among the two orders. Collectively, these patterns suggest that plants and insects converge in overall patterns of volatile production, both for attraction and defence. Monoterpenes seem to have evolved primarily for defence under selection by herbivores, whereas aromatics evolved signalling functions in angiosperms, primarily for pollinator attraction.

NHEXAS PHASE I MARYLAND STUDY--STANDARD OPERATING PROCEDURE FOR COLLECTION, STORAGE, AND SHIPMENT OF BLOOD SAMPLES FOR METAL, PESTICIDE, PAH, VOC, AND LIPID ANALYSIS (F11)

EPA Science Inventory

The purpose of this SOP is to describe collection, storage, and shipment requirements of blood samples for metal, pesticide, polynuclear aromatic hydrocarbons (PAHs), volatile organic compound (VOC), and lipid analysis. Seven samples were taken from a single puncture: two 3-mL t...

Through oven transfer adsorption-desorption interface for the analysis of methyl jasmonate in aromatic samples by on-line RPLC-GC.

PubMed

Flores, Gema; Blanch, Gracia Patricia; Ruiz del Castillo, Maria Luisa

2008-04-01

A fully automated method for the determination of medium volatility compounds in aromatic samples was developed. Specifically, the determination of methyl jasmonate in jasmine fragrances was performed by using the through oven transfer adsorption-desorption (TOTAD) interface for the on-line coupling between RPLC-GC. A study of the most relevant variables involved in the performance of the TOTAD interface for medium volatility compounds was carried out by testing different values of helium flow (100, 300, 400, and 500 mL/min), transfer speed (0.1, 0.3, 0.5, and 2.0 mL/min), and methanol/water percentages (86:14, 85:15, 83:17, 80:20, and 70:30). The method developed provided satisfactory repeatability (RSD for retention times of 0.15% and for peak areas of 9.4%) and recovery (71%) as well as excellent LOD (0.01 mg/L) for methyl jasmonate in commercial jasmine essence under the experimental conditions selected as optimum. Additional advantages of the automated RPLC-TOTAD-GC method proposed in the present work are its rapidness, reliability, and the possibility of directly introducing the sample with no further pretreatment.

Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds.

PubMed

Schantz, Michele M; Benner, Bruce A; Heckert, N Alan; Sander, Lane C; Sharpless, Katherine E; Vander Pol, Stacy S; Vasquez, Y; Villegas, M; Wise, Stephen A; Alwis, K Udeni; Blount, Benjamin C; Calafat, Antonia M; Li, Zheng; Silva, Manori J; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G; Sjödin, Andreas

2015-04-01

Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers' Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers' Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants.

Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds

PubMed Central

Schantz, Michele M.; Benner, Bruce A.; Heckert, N. Alan; Sander, Lane C.; Sharpless, Katherine E.; Vander Pol, Stacy S.; Vasquez, Y.; Villegas, M.; Wise, Stephen A.; Alwis, K. Udeni; Blount, Benjamin C.; Calafat, Antonia M.; Li, Zheng; Silva, Manori J.; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G.; Sjödin, Andreas

2016-01-01

Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers’ Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers’ Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants. PMID:25651899

Volatile chemicals identified in extracts from leaves of Japanese mugwort (Artemisia princeps pamp.).

PubMed

Umano, K; Hagi, Y; Nakahara, K; Shoji, A; Shibamoto, T

2000-08-01

Extracts from leaves of Japanese mugwort (Artemisia princeps Pamp.) were obtained using two methods: steam distillation under reduced pressure followed by dichloromethane extraction (DRP) and simultaneous purging and extraction (SPSE). A total of 192 volatile chemicals were identified in the extracts obtained by both methods using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). They included 47 monoterpenoids (oxygenated monoterpenes), 26 aromatic compounds, 19 aliphatic esters, 18 aliphatic alcohols, 17 monoterpenes (hydrocarbon monoterpenes), 17 sesquiterpenes (hydrocarbon sesquiterpenes), 13 sesquiterpenoids (oxygenated sesquiterpenes), 12 aliphatic aldehydes, 8 aliphatic hydrocarbons, 7 aliphatic ketones, and 9 miscellaneous compounds. The major volatile constituents of the extract by DRP were borneol (10.27 ppm), alpha-thujone (3.49 ppm), artemisia alcohol (2.17 ppm), verbenone (1.85 ppm), yomogi alcohol (1.50 ppm), and germacren-4-ol (1.43 ppm). The major volatile constituents of the extract by SPSE were 1,8-cineole (8.12 ppm), artemisia acetate (4.22 ppm), alpha-thujone (3.20 ppm), beta-caryophyllene (2.39 ppm), bornyl acetate (2.05 ppm), borneol (1.80 ppm), and trans-beta-farnesene (1. 78 ppm).

Methodology for exposing avian embryos to quantified levels of airborne aromatic compounds associated with crude oil spills.

PubMed

Dubansky, Benjamin; Verbeck, Guido; Mach, Phillip; Burggren, Warren

2018-03-01

Oil spills on birds and other organisms have focused primarily on direct effects of oil exposure through ingestion or direct body fouling. Little is known of indirect effects of airborne volatiles from spilled oil, especially on vulnerable developing embryos within the bird egg. Here a technique is described for exposing bird embryos in the egg to quantifiable amounts of airborne volatile toxicants from Deepwater Horizon crude oil. A novel membrane inlet mass spectrometry system was used to measure major classes of airborne oil-derived toxicants and correlate these exposures with biological endpoints. Exposure induced a reduction in platelet number and increase in osmolality of the blood of embryos of the chicken (Gallus gallus). Additionally, expression of cytochrome P4501A, a protein biomarker of oil exposure, occurred in renal, pulmonary, hepatic and vascular tissues. These data confirm that this system for generating and measuring airborne volatiles can be used for future in-depth analysis of the toxicity of volatile organic compounds in birds and potentially other terrestrial organisms. Copyright © 2018 Elsevier B.V. All rights reserved.

Power-dependent speciation of volatile organic compounds in aircraft exhaust

NASA Astrophysics Data System (ADS)

Beyersdorf, Andreas J.; Thornhill, K. Lee; Winstead, Edward L.; Ziemba, Luke D.; Blake, Donald R.; Timko, Michael T.; Anderson, Bruce E.

2012-12-01

As part of the third NASA Aircraft Particle Emissions Experiment (APEX-3, November 2005), whole air samples were collected to determine the emission rates of volatile organic compounds (VOCs) from aircraft equipped with three different gas-turbine engines (an Allison Engine 3007-A1E, a Pratt-Whitney 4158, and a Rolls-Royce RB211-535E4B). Samples were collected 1 m behind the engine exhaust plane of the engines while they were operated at powers ranging from idle up to 30% of maximum rated thrust. Exhaust emission indices (mass emitted per kilogram of fuel used) for CO and non-methane hydrocarbons (NMHCs) were calculated based on enhancements over background relative to CO2. Emissions of all NMHCs were greatest at low power with values decreasing by an order of magnitude with increasing power. Previous studies have shown that scaling idle hydrocarbon emissions to formaldehyde or ethene (which are typically emitted at a ratio of 1-to-1 at idle) reduces variability amongst engine types. NMHC emissions were found to scale at low power, with alkenes contributing over 50% of measured NMHCs. However, as the power increases hydrocarbon emissions no longer scale to ethene, as the aromatics become the dominant species emitted. This may be due in part to a shift in combustion processes from thermal cracking (producing predominantly alkenes) to production of new molecules (producing proportionally more aromatics) as power increases. The formation of these aromatics is an intermediate step in the production of soot, which also increases with increasing power. The increase in aromatics relative to alkenes additionally results in a decrease in the hydroxyl radical reactivity and ozone formation potential of aircraft exhaust. Samples collected 30 m downwind of the engine were also analyzed for NMHCs and carbonyl compounds (acetone, 2-butanone and C1-C9 aldehydes). Formaldehyde was the predominant carbonyl emitted; however, the ratio of ethene-to-formaldehyde varied between the aircraft, possibly due to the sampling of transient emissions such as engine start-up and power changes. A large portion of the measured emissions (27-42% by mass) in the plume samples was made up of hazardous air pollutants (HAPs) with oxygenated compounds being most significant.

Chemical composition, bioactive compounds, and volatiles of six table grape varieties (Vitis vinifera L.).

PubMed

Aubert, Christophe; Chalot, Guillaume

2018-02-01

Six table grape cultivars (Centennial Seedless, Chasselas, Italia, Italia Rubi, Alphonse Lavallée, and Muscat de Hambourg) were analyzed for their levels of soluble solids, titratable acidity, sugars, organic acids, vitamin C and E, carotenoids, polyphenolics and volatile compounds during two successive years. Descriptive sensory analyses of the six table grape varieties were also performed. Mainly due to anthocyanins, black cultivars had the highest total phenolic contents. Alphonse Lavallée had also both the highest levels of trans-resveratrol and piceid, and Muscat de Hambourg the highest levels of α-tocopherol, β-carotene and monoterpenols, well-known key aroma compounds in Muscat varieties having also interesting pharmacological properties. This study shows that the two traditional black French cultivars, Muscat de Hambourg and Alphonse Lavallée, are particularly rich in bioactive compounds and have a great potential for human health. Finally, Muscat de Hambourg was significantly rated sweeter, juicier and more aromatic than the others cultivars. Copyright © 2017 Elsevier Ltd. All rights reserved.

Catalytic pyrolysis of wheat bran for hydrocarbons production in the presence of zeolites and noble-metals by using TGA-FTIR method.

PubMed

Lazdovica, K; Liepina, L; Kampars, V

2016-05-01

Pyrolysis of wheat bran with or without catalysts was investigated using TGA-FTIR method in order to determine the influence of zeolite and noble metal catalysts on the evolution profile and relative yield of the volatile compounds. The addition of all catalysts decreased the volatile matter of wheat bran from 76.3% to 75.9%, 73.9%, 73.5%, 69.7% and increased the solid residue from 18.0% to 18.4%, 20.4%, 20.8%, 24.6% under the catalyst of ZSM-5, 5% Pd/C, MCM-41, and 5% Pt/C. Noble-metal catalysts had higher activity for deoxygenation of compounds containing carbonyl, carboxyl, and hydroxyl groups than zeolites. Degradation of nitrogen containing compounds atom proceeded better in presence of zeolites. Noble-metal catalysts promoted formation of aromatics and changed the profiles of evolved compounds whereas zeolites advanced formation of aliphatics and olefins. Copyright © 2016 Elsevier Ltd. All rights reserved.

[The composition of volatile components of cepe (Boletus edulis) and oyster mushrooms (Pleurotus ostreatus)].

PubMed

Misharina, T A; Mukhutdinova, S M; Zharikova, G G; Terenina, M B; Krikunova, N I

2009-01-01

The composition of aroma compounds in cooked and canned cepe (Boletus edulis) and in cooked oyster mushrooms (Pleurotus ostreatus) is studied using capillary gas chromatography and chromatography-mass spectrometry. It is found that unsaturated alcohols and ketones containing eight atoms of carbon determine the aroma of raw mushrooms and take part in the formation of the aroma of cooked mushrooms as well. The content of these compounds was the highest in canned cepes. In oyster mushrooms, the concentration of these alcohols and ketones was lower in comparison with cepes. The content of aliphatic and aromatic aldehydes was much higher in oyster mushrooms. Volatile aliphatic and heterocyclic Maillard reaction products and isomeric octenols and octenones formed the aroma of cooked and canned mushrooms.

Analytical procedures for environmental quality control. Volume 2. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, L.K.; Wang, M.H.S.

1989-01-15

This report covers sixteen important documents. Some examples are: The determination of the maximum total trihalomethane potential; Nationwide approval of alternative test procedure for analysis of trihalomethanes; Volatile organic compounds in eater by purge and trap capillary column gas chromatography with photoionization and electrolytic conductivity detectors in series; Analysis of organohalide pesticides and arclors in drinking water by microextraction and gas chromatography; Testing for lead in school drinking water; Simplified methods for food and feed testing; Determination of nitroaromatic compounds and isophorone in industrial and municipal wastewaters; Sampling for giardia and/or cryptosporidium; determination of TCDD in industrial and municipal wastewaters;more » Determination of volatile organics in industrial and municipal wastewaters; Determination of polynuclear aromatic hydrocarbons in industrial and municipal wastewaters.« less

Comparative Study of the Volatile Components of Fresh and Fermented Flowers of Alnus sieboldiana (Betulaceae).

PubMed

Ab Ghani, Nurunajah; Ismail, Nor Hadiani; Asakawa, Yoshinori

2016-02-01

Analysis of the volatile components present in the fresh male and female flowers and young leaves shows that 2-phenylethanol is the major component in all these three organs, which play a significant role in the strong resinous aromatic odor. The male flowers contained styrene as a second major compound. The level of styrene does not affect the male flowers odor concentration. The level of β-phenylethyl cinnamate and trans-methyl cinnamate in the fermented male flowers decreased as the fermentation time increased. This was due to the Penicillium enzymatic action on the fermented male flowers.

Characterization of volatile compounds produced by Lactobacillus helveticus strains in a hard cheese model.

PubMed

Cuffia, Facundo; Bergamini, Carina V; Wolf, Irma V; Hynes, Erica R; Perotti, María C

2018-01-01

Starter cultures of Lactobacillus helveticus used in hard cooked cheeses play an important role in flavor development. In this work, we studied the capacity of three strains of L. helveticus, two autochthonous (Lh138 and Lh209) and one commercial (LhB02), to grow and to produce volatile compounds in a hard cheese extract. Bacterial counts, pH, profiles of organic acids, carbohydrates, and volatile compounds were analyzed during incubation of extracts for 14 days at 37 ℃. Lactobacilli populations were maintained at 10 6 CFU ml -1 for Lh138, while decreases of approx. 2 log orders were found for LhB02 and Lh209. Both Lh209 and LhB02 slightly increased the acetic acid content whereas mild increase in lactic acid was produced by Lh138. The patterns of volatiles were dependent on the strain which reflect their distinct enzymatic machineries: LhB02 and Lh209 produced a greater diversity of compounds, while Lh138 was the least producer strain. Extracts inoculated with LhB02 and Lh 209 were characterized by ketones, esters, alcohols, aldehydes, and acids, whereas in the extracts with Lh138 the main compounds belonged to aromatic, aldehydes, and ketones groups. Therefore, Lh209 and LhB02 could represent the best cheese starters to improve and intensify the flavor, and even a starter composed by combinations of LhB02 or Lh209 with Lh138 could also be a strategy to diversify cheese flavor.

Yeast-yeast interactions revealed by aromatic profile analysis of Sauvignon Blanc wine fermented by single or co-culture of non-Saccharomyces and Saccharomyces yeasts.

PubMed

Sadoudi, Mohand; Tourdot-Maréchal, Raphaëlle; Rousseaux, Sandrine; Steyer, Damien; Gallardo-Chacón, Joan-Josep; Ballester, Jordi; Vichi, Stefania; Guérin-Schneider, Rémi; Caixach, Josep; Alexandre, Hervé

2012-12-01

There has been increasing interest in the use of selected non-Saccharomyces yeasts in co-culture with Saccharomyces cerevisiae. The main reason is that the multistarter fermentation process is thought to simulate indigenous fermentation, thus increasing wine aroma complexity while avoiding the risks linked to natural fermentation. However, multistarter fermentation is characterised by complex and largely unknown interactions between yeasts. Consequently the resulting wine quality is rather unpredictable. In order to better understand the interactions that take place between non-Saccharomyces and Saccharomyces yeasts during alcoholic fermentation, we analysed the volatile profiles of several mono-culture and co-cultures. Candida zemplinina, Torulaspora delbrueckii and Metschnikowia pulcherrima were used to conduct fermentations either in mono-culture or in co-culture with S. cerevisiae. Up to 48 volatile compounds belonging to different chemical families were quantified. For the first time, we show that C. zemplinina is a strong producer of terpenes and lactones. We demonstrate by means of multivariate analysis that different interactions exist between the co-cultures studied. We observed a synergistic effect on aromatic compound production when M. pulcherrima was in co-culture with S. cerevisiae. However a negative interaction was observed between C. zemplinina and S. cerevisiae, which resulted in a decrease in terpene and lactone content. These interactions are independent of biomass production. The aromatic profiles of T. delbrueckii and S. cerevisiae in mono-culture and in co-culture are very close, and are biomass-dependent, reflecting a neutral interaction. This study reveals that a whole family of compounds could be altered by such interactions. These results suggest that the entire metabolic pathway is affected by these interactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Health risk assessment and personal exposure to Volatile Organic Compounds (VOCs) in metro carriages - A case study in Shanghai, China.

PubMed

Gong, Yu; Wei, Yijie; Cheng, Jinghui; Jiang, Tianyao; Chen, Ling; Xu, Bin

2017-01-01

Air pollution in transportation cabins has recently become a public concern. However, few studies assessed the exposure levels of suspected air pollutants including Volatile Organic Compounds (VOCs). This paper studied the exposure levels of in-carriage VOCs (benzene, toluene, ethylbenzene, xylene, styrene, formaldehyde, acetaldehyde, acetone and acrolein) in Shanghai, China and estimated the health risk in different conditions. The results indicated that VOCs concentrations in metro carriages varied from different train models, due to the difference in carriage size and ventilation system. The concentrations of aromatic VOCs in old metro carriage were 1-2 times higher than the new ones, as better paintings were used in new trains. Poor air circulation and ventilation in the underground track was likely to be the cause of higher VOCs levels (~10%) than the above-ground track. Lower aromatic compounds levels and higher carbonyls levels were observed in metro carriages at suburban areas than those at urban areas, likely due to less aromatic emission sources and more carbonyls emission sources in suburban areas. Acetone and acrolein were found to increase from 7.71 to 26.28μg/m 3 with number of commuters increasing from 40 to 200 in the carriages. According to the acceptable level proposed by the World Health Organization (1×10 -6 -1×10 -5 ), the life carcinogenic risk of commuters by subway (8.5×10 -6 -4.8×10 -5 ) was little above the acceptable level in Shanghai. Further application of our findings is possible to act as a reference in facilitating regulations for metro systems in other cities around world, so that in-carriage air quality might be improved. Copyright © 2016 Elsevier B.V. All rights reserved.

Volatile organic compounds and isoprene oxidation products at a temperate deciduous forest site

NASA Astrophysics Data System (ADS)

Helmig, Detlev; Greenberg, Jim; Guenther, Alex; Zimmerman, Pat; Geron, Chris

1998-09-01

Biogenic volatile organic compounds (BVOCs) and their role in atmospheric oxidant formation were investigated at a forest site near Oak Ridge, Tennessee, as part of the Nashville Southern Oxidants Study (SOS) in July 1995. Of 98 VOCs detected, a major fraction were anthropogenic VOCs such as chlorofluorocarbons (CFCs), alkanes, alkenes and aromatic compounds. Isoprene was the dominant BVOC during daytime. Primary products from BVOC oxidation were methylvinylketone, methacrolein and 3-methylfuran. Other compounds studied include the BVOCs α-pinene, camphene, β-pinene, p-cymene, limonene and cis-3-hexenyl acetate and a series of light alkanes, aromatic hydrocarbons and seven of the CFCs. The correlation of meteorological parameters, with the mixing ratios of these different compounds, reveals information on atmospheric oxidation processes and transport. Long-lived VOCs show very steady mixing ratio time series. Regionally and anthropogenically emitted VOCs display distinct diurnal cycles with a strong mixing ratio decrease in the morning from the breakup of the nocturnal boundary layer. Nighttime mixing ratio increases of CFCs and anthropogenic VOCs are suspected to derive from emissions within the Knoxville urban area into the shallow nocturnal boundary layer. In contrast, the time series of BVOCs and their oxidation products are determined by a combination of emission control, atmospheric oxidation and deposition, and boundary layer dynamics. Mixing ratio time series data for monoterpenes and cis-3-hexenyl acetate suggest a temporarily emission rate increase during and after heavy rain events. The isoprene oxidation products demonstrate differences in the oxidation pathways during night and day and in their dry and wet deposition rates.

Influence of Fruit Ripening on Color, Organic Acid Contents, Capsaicinoids, Aroma Compounds, and Antioxidant Capacity of Shimatogarashi (Capsicum frutescens).

PubMed

Manikharda; Takahashi, Makoto; Arakaki, Mika; Yonamine, Kaoru; Hashimoto, Fumio; Takara, Kensaku; Wada, Koji

2018-01-01

Shimatogarashi (Capsicum frutescens) is a typical chili pepper domesticated in southern Japan. Important traits of Shimatogarashi peppers, such as color; proportion of organic acids, capsaicinoids, and aromatic compounds; and antioxidant activity in three stages of maturity (green (immature), orange (turning), and red (mature) stages) were characterized. The results indicated that the concentration of organic acids, including ascorbic, citric, and malic acid, increased during ripening. In addition, the amount of capsaicinoids, which are responsible for the pungent taste of chili peppers, increased as the fruit matured to the orange and red stages. The volatile compound profile of Shimatogarashi was dominated by the presence of esters, which mainly contributed to fruity notes. The total amount of volatile compounds analyzed by gas chromatography-headspace solid-phase microextraction (GC-HS-SPME), especially esters, decreased as the fruit changed in color from green to red. This was in contrast to the amount of terpenoids, especially limonene, which increased at the red stage, denoting a change in flavor from fruity to a more citrus-like aroma. Based on the total phenolic content (TPC), the oxygen radical absorbance capacity (ORAC) and the diphenylpicrylhydrazyl (DPPH) free radical method, the antioxidant capacity of Shimatogarashi showed an increase at the mature red stage. However, while the red stage showed higher pungency and antioxidant capacity as well as an attractive color, the results of aromatic compound analysis revealed that the immature green stage had the advantages of having pleasant fruity smell, making it suitable for use in condiments.

Volatile organic compounds in stormwater from a community of Beijing, China.

PubMed

Li, Haiyan; Wang, Youshu; Liu, Fei; Tong, Linlin; Li, Kun; Yang, Hua; Zhang, Liang

2018-08-01

Stormwater samples were collected from six different land use sites with three time-intervals during a precipitation event on August 12, 2016, from a community of Beijing, China. A total of 46 species volatile organic compounds (VOCs) were detected in these stormwater samples, including methyl tertiary-butyl ether (MTBE), aromatic hydrocarbons, halogenated aromatics, Halogenated alkanes, and alkenes. The total VOC concentrations varied in the six sites following order: highway junction > city road > gas station > park > campus > residential area, except for MTBE, which was much higher at gas station compared to other land use sites. ANOVA results indicated both land use and precipitation time intervals could significantly affect the VOC concentrations even in the small area. The Beijing atmospheric VOC concentrations were too low to explain the high concentrations in stormwater, suggesting that land surfaces may be the main sources of VOC other than the ambient atmosphere. MTBE and other VOCs correlation analysis indicated that MTBE mostly came from gasoline emissions, spills or vehicle exhausts, whereas the BTEX (benzene, toluene, ethylbenzene, Xylenes) and the halogenated aromatics were transferred from chemical plants through land surfaces accumulating and the wind blowing atmospheric VOCs. Xylenes/ethylbenzene (X/E) ratios variations indicated that stormwater incorporated larger amount of fresh emitted air during the precipitation event than prior to it. Information of these stormwater VOCs in this study could be used in the community pollution reduction strategies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Vehicle occupants' exposure to aromatic volatile organic compounds while commuting on an urban-suburban route in Korea.

PubMed

Jo, W K; Choi, S J

1996-08-01

This study identified in-auto and in-bus exposures to six selected aromatic volatile organic compounds (VOCs) for commutes on an urban-suburban route in Korea. A bus-service route was selected to include three segments of Taegu and one suburban segment (Hayang) to satisfy the criteria specified for this study. This study indicates that motor vehicle exhaust and evaporative emissions are major sources of both auto and bus occupants' exposures to aromatic VOCs in both Taegu and Hayang. A nonparametric statistical test (Wilcoxon test) showed that in-auto benzene levels were significantly different from in-bus benzene levels for both urban-segment and suburban-segment commutes. The test also showed that the benzene-level difference between urban-segment and suburban-segment commutes was significant for both autos and buses. An F-test showed the same statistical results for the comparison of the summed in-vehicle concentration of the six target VOCs (benzene, toluene, ethylbenzene, and o,m,p-xylenes) as those for the comparison of the in-vehicle benzene concentration. On the other hand, the in-vehicle benzene level only and the sum were not significantly different among the three urban-segment commutes and between the morning and evening commutes. The in-auto VOC concentrations were intermediate between the results for the Los Angeles and Boston. The in-bus VOC concentrations were about one-tenth of the Taipei, Taiwan results.

The contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect.

PubMed

Amitsuka, Takahiko; Okamura, Maya; Mukuta, Kei; Shiibashi, Hiroko; Haraguchi, Kenji; Saito, Tsukasa; Inoue, Kazuo; Fushiki, Tohru

2017-08-01

Katsuodashi, a dried bonito broth, is very basic and indispensable in Japanese cuisine and contains taste-exhibiting components and unique aroma. We previously reported that its unique aroma contributes to the preference and reinforcement effect associated with dried bonito. This study aims to elucidate the contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect. Volatile components obtained from dried bonito were fractionated and the fractions were subjected to two-bottle choice test. The fractionation test suggested that the component responsible for the preference is not one but comprises multiple components. In the GC-MS analysis/reconstruction test, solution with aromatic flavor narrowed down to 125 compounds had preference, and also had reinforcement effect. Moreover, GC-MS-olfactometry analysis narrowed down the candidate components to 28 out of 125. Mice showed preference for the test solution with aromatic flavor reconstructed with 28 components but did not show reinforcement behavior.

Radiolysis of N-acetyl amino acids as model compounds for radiation degradation of polypeptides

NASA Astrophysics Data System (ADS)

Wayne Garrett, R.; Hill, David J. T.; Ho, Sook-Ying; O'Donnell, James H.; O'Sullivan, Paul W.; Pomery, Peter J.

Radiation chemical yields of (i) the volatile radiolysis products and (ii) the trapped free radicals from the y-radiolysis of the N-acetyl derivatives of glycine, L-valine, L-phenylalanine and L-tyrosine in the polycrystalline state have been determined at room temperature (303 K). Carbon dioxide was found to be the major molecular product for all these compounds with G(CO 2) varying from 0.36 for N-acetyl-L-tyrosine to 8 for N-acetyl-L-valine. There was evidence for some scission of the N-C α bond, indicated by the production of acetamide and the corresponding aliphatic acid, but the determination reaction was found to be of much lesser importance than the decarboxylation reaction. A protective effect of the aromatic ring in N-acetyl-L-phenylalanine and in N-acetyl-L-tyrosine was indicated by the lower yields of volatile products for these compounds. The yields of trapped free radicals were found to vary with the nature of the amino acid side chain, increasing with chain length and chain branching. The radical yields were decreased by incorporation of an aromatic moiety in the side chain, this effect being greater for the tyrosyl side chain than for the phenyl side chain. The G(R·) values showed a good correlation with G(CO 2) indicating that a common reaction may be involved in radical production and carbon dioxide formation.

Microbial communities related to volatile organic compound emission in automobile air conditioning units.

PubMed

Diekmann, Nina; Burghartz, Melanie; Remus, Lars; Kaufholz, Anna-Lena; Nawrath, Thorben; Rohde, Manfred; Schulz, Stefan; Roselius, Louisa; Schaper, Jörg; Mamber, Oliver; Jahn, Dieter; Jahn, Martina

2013-10-01

During operation of mobile air conditioning (MAC) systems in automobiles, malodours can occur. We studied the microbial communities found on contaminated heat exchanger fins of 45 evaporators from car MAC systems which were operated in seven different regions of the world and identified corresponding volatile organic compounds. Collected biofilms were examined by scanning electron microscopy and fluorescent in situ hybridization. The detected bacteria were loosely attached to the metal surface. Further analyses of the bacteria using PCR-based single-strand conformation polymorphism and sequencing of isolated 16S rRNA gene fragments identified highly divergent microbial communities with multiple members of the Alphaproteobacteriales, Methylobacteria were the prevalent bacteria. In addition, Sphingomonadales, Burkholderiales, Bacillales, Alcanivorax spp. and Stenotrophomonas spp. were found among many others depending on the location the evaporators were operated. Interestingly, typical pathogenic bacteria related to air conditioning systems including Legionella spp. were not found. In order to determine the nature of the chemical compounds produced by the bacteria, the volatile organic compounds were examined by closed loop stripping analysis and identified by combined gas chromatography/mass spectrometry. Sulphur compounds, i.e. di-, tri- and multiple sulphides, acetylthiazole, aromatic compounds and diverse substituted pyrazines were detected. Mathematical clustering of the determined microbial community structures against their origin identified a European/American/Arabic cluster versus two mainly tropical Asian clusters. Interestingly, clustering of the determined volatiles against the origin of the corresponding MAC revealed a highly similar pattern. A close relationship of microbial community structure and resulting malodours to the climate and air quality at the location of MAC operation was concluded.

Electric-field triggered controlled release of bioactive volatiles from imine-based liquid crystalline phases.

PubMed

Herrmann, Andreas; Giuseppone, Nicolas; Lehn, Jean-Marie

2009-01-01

Application of an electric field to liquid crystalline film forming imines with negative dielectric anisotropy, such as N-(4-methoxybenzylidene)-4-butylaniline (MBBA, 1), results in the expulsion of compounds that do not participate in the formation of the liquid crystalline phase. Furthermore, amines and aromatic aldehydes undergo component exchange with the imine by generating constitutional dynamic libraries. The strength of the electric field and the duration of its application to the liquid crystalline film influence the release rate of the expelled compounds and, at the same time, modulate the equilibration of the dynamic libraries. The controlled release of volatile organic molecules with different chemical functionalities from the film was quantified by dynamic headspace analysis. In all cases, higher headspace concentrations were detected in the presence of an electric field. These results point to the possibility of using imine-based liquid crystalline films to build devices for the controlled release of a broad variety of bioactive volatiles as a direct response to an external electric signal.

Laboratory measurements of emissions of nonmethane volatile organic compounds from biomass burning in Chinese crop residues

NASA Astrophysics Data System (ADS)

Inomata, S.; Tanimoto, H.; PAN, X.; Taketani, F.; Komazaki, Y.; Miyakawa, T.; Kanaya, Y.; Wang, Z.

2014-12-01

The emission factors (EFs) of volatile organic compounds (VOCs) from the burning of Chinese crop residue were investigated as a function of modified combustion efficiency by the laboratory experiments. The VOCs including acetonitrile, aldehydes/ketones, furan, and aromatic hydrocarbons were monitored by proton-transfer-reaction mass spectrometry. Two samples, wheat straw and rape plant, were burned in dry conditions and for some experiments wheat straw was burned under wet conditions. We compared the present data to the field data reported by Kudo et al. [2014]. The agreement between the field and laboratory data was obtained for aromatics for relatively more smoldering data of dry samples but the field data were slightly underestimated compared with the laboratory data for oxygenated VOCs (OVOCs) and acetonitrile. When the EFs from the burning of wet samples were investigated, the underestimations for OVOCs and acetonitrile were improved compared with the data of dry samples. It may be a property of the burning of crop residue in the region of high temperature and high humidity that some inside parts of piled crop residue and/or the crop residue facing on the ground are still wet. But the ratios for acetic acid/glycolaldehyde was still lower than 1. This may suggest that strong loss processes of acetic acid/glycolaldehyde are present in the fresh plume.Kudo S., H. Tanimoto, S. Inomata, S. Saito, X. L. Pan, Y. Kanaya, F. Taketani, Z. F. Wang, H. Chen, H. Dong, M. Zhang, and K. Yamaji (2014), Emissions of nonmethane volatile organic compounds from open crop residue burning in Yangtze River Delta region, China, J. Geophys. Res. Atmos., 119, 7684-7698, doi: 10.1002/2013JD021044.

Concentrations in human blood of petroleum hydrocarbons associated with the BP/Deepwater Horizon oil spill, Gulf of Mexico.

PubMed

Sammarco, Paul W; Kolian, Stephan R; Warby, Richard A F; Bouldin, Jennifer L; Subra, Wilma A; Porter, Scott A

2016-04-01

During/after the BP/Deepwater Horizon oil spill, cleanup workers, fisherpersons, SCUBA divers, and coastal residents were exposed to crude oil and dispersants. These people experienced acute physiological and behavioral symptoms and consulted a physician. They were diagnosed with petroleum hydrocarbon poisoning and had blood analyses analyzed for volatile organic compounds; samples were drawn 5-19 months after the spill had been capped. We examined the petroleum hydrocarbon concentrations in the blood. The aromatic compounds m,p-xylene, toluene, ethylbenzene, benzene, o-xylene, and styrene, and the alkanes hexane, 3-methylpentane, 2-methylpentane, and iso-octane were detected. Concentrations of the first four aromatics were not significantly different from US National Health and Nutritional Examination Survey/US National Institute of Standards and Technology 95th percentiles, indicating high concentrations of contaminants. The other two aromatics and the alkanes yielded equivocal results or significantly low concentrations. The data suggest that single-ring aromatic compounds are more persistent in the blood than alkanes and may be responsible for the observed symptoms. People should avoid exposure to crude oil through avoidance of the affected region, or utilizing hazardous materials suits if involved in cleanup, or wearing hazardous waste operations and emergency response suits if SCUBA diving. Concentrations of alkanes and PAHs in the blood of coastal residents and workers should be monitored through time well after the spill has been controlled.

Evaluation of quicklime mixing for the remediation of petroleum contaminated soils.

PubMed

Schifano, V; Macleod, C; Hadlow, N; Dudeney, R

2007-03-15

Quicklime mixing is an established solidification/stabilization technique to improve mechanical properties and immobilise contaminants in soils. This study examined the effects of quicklime mixing on the concentrations and leachability of petroleum hydrocarbon compounds, in two natural soils and on a number of artificial sand/kaolinite mixtures. Several independent variables, such as clay content, moisture content and quicklime content were considered in the study. After mixing the soils with the quicklime, pH, temperature, moisture content, Atterberg limits and concentrations of petroleum hydrocarbon compounds were determined on soil and leachate samples extracted from the treated soils. Significant decreases in concentrations of petroleum hydrocarbon compounds were measured in soils and leachates upon quicklime mixing, which may be explained by a number of mechanisms such as volatilization, degradation and encapsulation of the hydrocarbon compounds promoted by the quicklime mixing. The increase in temperature due to the exothermic hydration reaction of quicklime when in contact with porewater helps to volatilize the light compounds but may not be entirely responsible for their concentration decreases and for the decrease of heavy aliphatics and aromatics concentrations.

Metal organic frameworks as sorption media for volatile and semi-volatile organic compounds at ambient conditions

PubMed Central

Vellingiri, Kowsalya; Szulejko, Jan E.; Kumar, Pawan; Kwon, Eilhann E.; Kim, Ki-Hyun; Deep, Akash; Boukhvalov, Danil W.; Brown, Richard J. C.

2016-01-01

In this research, we investigated the sorptive behavior of a mixture of 14 volatile and semi-volatile organic compounds (four aromatic hydrocarbons (benzene, toluene, p-xylene, and styrene), six C2-C5 volatile fatty acids (VFAs), two phenols, and two indoles) against three metal-organic frameworks (MOFs), i.e., MOF-5, Eu-MOF, and MOF-199 at 5 to 10 mPa VOC partial pressures (25 °C). The selected MOFs exhibited the strongest affinity for semi-volatile (polar) VOC molecules (skatole), whereas the weakest affinity toward was volatile (non-polar) VOC molecules (i.e., benzene). Our experimental results were also supported through simulation analysis in which polar molecules were bound most strongly to MOF-199, reflecting the presence of strong interactions of Cu2+ with polar VOCs. In addition, the performance of selected MOFs was compared to three well-known commercial sorbents (Tenax TA, Carbopack X, and Carboxen 1000) under the same conditions. The estimated equilibrium adsorption capacity (mg.g−1) for the all target VOCs was in the order of; MOF-199 (71.7) >Carboxen-1000 (68.4) >Eu-MOF (27.9) >Carbopack X (24.3) >MOF-5 (12.7) >Tenax TA (10.6). Hopefully, outcome of this study are expected to open a new corridor to expand the practical application of MOFs for the treatment diverse VOC mixtures. PMID:27324522

Chemical and biological characterization of products of incomplete combustion from the simulated field burning of agricultural plastic.

PubMed

Linak, W P; Ryan, J V; Perry, E; Williams, R W; DeMarini, D M

1989-06-01

Chemical and biological analyses were performed to characterize products of incomplete combustion emitted during the simulated open field burning of agricultural plastic. A small utility shed equipped with an air delivery system was used to simulate pile burning and forced-air-curtain incineration of a nonhalogenated agricultural plastic that reportedly consisted of polyethylene and carbon black. Emissions were analyzed for combustion gases; volatile, semi-volatile, and particulate organics; and toxic and mutagenic properties. Emission samples, as well as samples of the used (possibly pesticide-contaminated) plastic, were analyzed for the presence of several pesticides to which the plastic may have been exposed. Although a variety of alkanes, alkenes, and aromatic and polycyclic aromatic hydrocarbon (PAH) compounds were identified in the volatile, semi-volatile, and particulate fractions of these emissions, a substantial fraction of higher molecular weight organic material was not identified. No pesticides were identified in either combustion emission samples or dichloromethane washes of the used plastic. When mutagenicity was evaluated by exposing Salmonella bacteria (Ames assay) to whole vapor and vapor/particulate emissions, no toxic or mutagenic effects were observed. However, organic extracts of the particulate samples were moderately mutagenic. This mutagenicity compares approximately to that measured from residential wood heating on a revertant per unit heat release basis. Compared to pile burning, forced air slightly decreased the time necessary to burn a charge of plastic. There was not a substantial difference, however, in the variety or concentrations of organic compounds identified in samples from these two burn conditions. This study highlights the benefits of a combined chemical/biological approach to the characterization of complex, multi-component combustion emissions. These results may not reflect those of other types of plastic that may be used for agricultural purposes, especially those containing halogens.

Speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) in a pine forest during BEACHON-RoMBAS 2011

DOE PAGES

Chan, A. W. H.; Kreisberg, N. M.; Hohaus, T.; ...

2016-02-02

Understanding organic composition of gases and particles is essential to identifying sources and atmospheric processing leading to organic aerosols (OA), but atmospheric chemical complexity and the analytical techniques available often limit such analysis. Here we present speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) using a novel dual-use instrument (SV-TAG-AMS) deployed at Manitou Forest, CO, during the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H 2O, Organics & Nitrogen – Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS) 2011 campaign. This instrument provides on-line speciation of ambient organic compounds with 2 h time resolution. The species in this volatility range aremore » complex in composition, but their chemical identities reveal potential sources. Observed compounds of biogenic origin include sesquiterpenes with molecular formula C 15H 24 (e.g., β-caryophyllene and longifolene), which were most abundant at night. A variety of other biogenic compounds were observed, including sesquiterpenoids with molecular formula C 15H 22, abietatriene and other terpenoid compounds. Many of these compounds have been identified in essential oils and branch enclosure studies but were observed in ambient air for the first time in our study. Semivolatile polycyclic aromatic hydrocarbons (PAHs) and alkanes were observed with highest concentrations during the day and the dependence on temperature suggests the role of an evaporative source. Using statistical analysis by positive matrix factorization (PMF), we classify observed S/IVOCs by their likely sources and processes, and characterize them based on chemical composition. The total mass concentration of elutable S/IVOCs was estimated to be on the order of 0.7 µg m –3 and their volatility distributions are estimated for modeling aerosol formation chemistry.« less

Speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) in a pine forest during BEACHON-RoMBAS 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chan, A. W. H.; Kreisberg, N. M.; Hohaus, T.

Understanding organic composition of gases and particles is essential to identifying sources and atmospheric processing leading to organic aerosols (OA), but atmospheric chemical complexity and the analytical techniques available often limit such analysis. Here we present speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) using a novel dual-use instrument (SV-TAG-AMS) deployed at Manitou Forest, CO, during the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H 2O, Organics & Nitrogen – Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS) 2011 campaign. This instrument provides on-line speciation of ambient organic compounds with 2 h time resolution. The species in this volatility range aremore » complex in composition, but their chemical identities reveal potential sources. Observed compounds of biogenic origin include sesquiterpenes with molecular formula C 15H 24 (e.g., β-caryophyllene and longifolene), which were most abundant at night. A variety of other biogenic compounds were observed, including sesquiterpenoids with molecular formula C 15H 22, abietatriene and other terpenoid compounds. Many of these compounds have been identified in essential oils and branch enclosure studies but were observed in ambient air for the first time in our study. Semivolatile polycyclic aromatic hydrocarbons (PAHs) and alkanes were observed with highest concentrations during the day and the dependence on temperature suggests the role of an evaporative source. Using statistical analysis by positive matrix factorization (PMF), we classify observed S/IVOCs by their likely sources and processes, and characterize them based on chemical composition. The total mass concentration of elutable S/IVOCs was estimated to be on the order of 0.7 µg m –3 and their volatility distributions are estimated for modeling aerosol formation chemistry.« less

Discrimination of cherry wines based on their sensory properties and aromatic fingerprinting using HS-SPME-GC-MS and multivariate analysis.

PubMed

Xiao, Zuobing; Liu, Shengjiang; Gu, Yongbo; Xu, Na; Shang, Yi; Zhu, Jiancai

2014-03-01

Volatiles of cherry wines were extracted by headspace solid phase microextraction (HS-SPME) and analyzed by gas chromatography mass spectrometry (GC-MS), multivariate statistical techniques (such as principal component analysis (PCA) and cluster analysis (CA) and correlation analysis) to differentiate sensory attributes of 3 groups of the wines through characterization of volatiles of cherry wine. Seventy-five volatiles were identified in 9 samples, including 29 esters, 22 alcohols, 8 acids, 3 ketones, 5 aldehydes, and 8 miscellaneous compounds. The PCA results showed that the cherry wines were mainly differentiated by 8 sensory attributes. The samples W2, W4, and W7 were grouped around sweet aromatic and the samples W1, W5, and W9 were highly associated with the sweet, esters, green, bitter, and fermented. Nevertheless, the samples W3, W6, and W8 were located close to the sour, alcoholic, and fruity. The final result of correlation analysis was in conformity with the conclusion of PCA. The CA results showed that the group of W2, W4, and W7, and the group of W1, W5, and W9 had less difference than the group of W3, W6, and W8. The reason should be that esterification reactions and fermentation process during the ageing period was more extended. The results of analyzing revealed that HS-SPME-GC-MS coupled with chemometrics could give an appropriate way of characterizing and classifying the cherry wines. Attributes that represent and discriminate among cherry wines might be made use of a better comprehending of the wines and for being utilized in future work. In addition, several chemometrics were used to classify the type of wines and try to install the relationship between volatiles and sensory property. Especially, PCA clearly revealed that the most contributing compounds for sensory attributes of cherry wines, CA was a more applicable way to distinguish types of cherry wines. Therefore, a feasible method that would be helpful to promote the quality of the wines by improving the winemaking process and analyzing aromatic characteristics of wines. © 2014 Institute of Food Technologists®

Cumulative Exposure Assessment for Trace-Level Polycyclic Aromatic Hydrocarbons (PAHs) using Human Blood and Plasma Analysis

EPA Science Inventory

Humans experience chronic cumulative trace-level exposure to mixtures of volatile, semi-volatile, and non-volatile polycyclic aromatic hydrocarbons (PAHs) present in the environment as by-products of combustion processes. Certain PAHs are known or suspected human carcinogens and ...

Modelling bioaccumulation of semi-volatile organic compounds (SOCs) from air in plants based on allometric principles.

PubMed

Steyaert, Nils L L; Hauck, Mara; Van Hulle, Stijn W H; Hendriks, A Jan

2009-10-01

A model was developed for gaseous plant-air exchange of semi-volatile organic compounds. Based on previous soil-plant modelling, uptake and elimination kinetics were scaled as a function of plant mass and octanol-air partition ratios. Exchange of chemicals was assumed to be limited by resistances encountered during diffusion through a laminar boundary layer of air and permeation through the cuticle of the leaf. The uptake rate constant increased and the elimination rate constant decreased with the octanol-air partition ratio both apparently levelling off at high values. Differences in kinetics between species could be explained by their masses. Validation on independent data showed that bio-concentration factors of PCBs, chlorobenzenes and other chemicals were predicted well by the model. For pesticides, polycyclic aromatic hydrocarbons and dioxins deviations occurred.

JEM Spotlight: Fungi, mycotoxins and microbial volatile organic compounds in mouldy interiors from water-damaged buildings.

PubMed

Polizzi, Viviana; Delmulle, Barbara; Adams, An; Moretti, Antonio; Susca, Antonia; Picco, Anna Maria; Rosseel, Yves; Kindt, Ruben't; Van Bocxlaer, Jan; De Kimpe, Norbert; Van Peteghem, Carlos; De Saeger, Sarah

2009-10-01

Concerns have been raised about exposure to mycotoxin producing fungi and the microbial volatile organic compounds (MVOCs) they produce in indoor environments. Therefore, the presence of fungi and mycotoxins was investigated in 99 samples (air, dust, wallpaper, mycelium or silicone) collected in the mouldy interiors of seven water-damaged buildings. In addition, volatile organic compounds (VOCs) were sampled. The mycotoxins were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) (20 target mycotoxins) and quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS). Morphological and molecular identifications of fungi were performed. Of the 99 samples analysed, the presence of one or more mycotoxins was shown in 62 samples by means of LC-MS/MS analysis. The mycotoxins found were mainly roquefortine C, chaetoglobosin A and sterigmatocystin but also roridin E, ochratoxin A, aflatoxin B(1) and aflatoxin B(2) were detected. Q-TOF-MS analysis elucidated the possible occurrence of another 42 different fungal metabolites. In general, the fungi identified matched well with the mycotoxins detected. The most common fungal species found were Penicillium chrysogenum, Aspergillus versicolor (group), Chaetomium spp. and Cladosporium spp. In addition, one hundred and seventeen (M)VOCs were identified, especially linear alkanes (C(9)-C(17)), aldehydes, aromatic compounds and monoterpenes.

Effect of sequential fermentations and grape cultivars on volatile compounds and sensory profiles of Danish wines.

PubMed

Liu, Jing; Arneborg, Nils; Toldam-Andersen, Torben B; Petersen, Mikael A; Bredie, Wender Lp

2017-08-01

There has been an increasing interest in the use of selected non-Saccharomyces yeasts in co-culture with Saccharomyces cerevisiae. In this work, three non-Saccharomyces yeast strains (Metschnikowia viticola, Metschnikowia fructicola and Hanseniaspora uvarum) indigenously isolated in Denmark were used in sequential fermentations with S. cerevisiae on three cool-climate grape cultivars, Bolero, Rondo and Regent. During the fermentations, the yeast growth was determined as well as key oenological parameters, volatile compounds and sensory properties of finished rosé wines. The different non-Saccharomyces strains and cool-climate grape cultivars produced wines with a distinctive aromatic profile. A total of 67 volatile compounds were identified, including 43 esters, 14 alcohols, five acids, two ketones, a C13-norisoprenoid, a lactone and a sulfur compound. The use of M. viticola in sequential fermentation with S. cerevisiae resulted in richer berry and fruity flavours in wines. The sensory plot showed a more clear separation among wine samples by grape cultivars compared with yeast strains. Knowledge on the influence of indigenous non-Saccharomyces strains and grape cultivars on the flavour generation contributed to producing diverse wines in cool-climate wine regions. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Manmade organic compounds in the surface waters of the United States: a review of current understanding

USGS Publications Warehouse

Smith, James A.; Witkowski, Patrick J.; Fusillo, Thomas V.

1987-01-01

This report reviews the occurrence and distribution of manmade organic compounds in the surface waters of the United States. On the basis of their aqueous solubilities, nonionic organic compounds partition themselves between water, dissolved organic matter, particulate organic matter, and the lipid reservoirs of aquatic organisms. Ionized organic compounds can be absorbed to sediments, thereby reducing their aqueous concentrations. Transformation processes of photolysis, hydrolysis, biodegradation, and volatilization can attenuate organic compounds, and attenuation rate commonly follow a first-order kinetic process. Eight groups of manmade organic compounds are discussed: 1. Polychlorinated biphenyls and organochlorine insecticides, 2. Carbamate and organophosphorus insecticides, 3. Herbicides, 4. Phenols, 5. Halogenated aliphatic and monocyclic aromatic hydrocarbons, 6. Phthalate esters, 7. Polychlorinated dibenzo-p-dioxins, and 8. Polycyclic aromatic hydrocarbons. For each compound group, data pertaining to use, production, and properties are presented and discussed. Processes that influence that the environmental fate of each group, as determined primarily through laboratory studies, are reviewed, and important fate processes are identified. Environmental concentrations of compounds from each group in water, biota, and sediment are given to demonstrate representative values for comparison to concentrations determined during ongoing research. Finally, where sufficient data exist, regional and temporal contamination trends in the United States are discussed.

Manmade organic compounds in the surface waters of the United States; a review of current understanding

USGS Publications Warehouse

Smith, James A.; Witkowski, P.J.; Fusillo, Thomas V.

1988-01-01

This report reviews the occurrence and distribution of manmade organic compounds in the surface waters of the United States. On the basis of their aqueous solubilities, nonionic organic compounds partition themselves among water, dissolved organic matter, particulate organic matter, and the lipid reservoirs of aquatic organisms. Ionized organic compounds can be adsorbed to sediments, thereby reducing their aqueous concentrations. Transformation processes of photolysis, hydrolysis, biodegradation, and volatilization can attenuate organic compounds, and attenuation rates commonly follow a first-order kinetic process. Eight groups of manmade organic compounds are discussed: 1. Polychlorinated biphenyls and organochlorine insecticides, 2. Carbamate and organophosphorus insecticides, 3. Herbicides, 4. Phenols, 5. Halogenated aliphatic and monocyclic aromatic hydrocarbons, 6. Phthalate esters, 7. Polychlorinated dibenzo-p-dioxins, and 8. Polycyclic aromatic hydrocarbons. For each compound group, data pertaining to use, production, and properties are presented and discussed. Processes that influence the environmental fate of each group, as determined primarily through laboratory studies, are reviewed, and important fate processes are identified. Environmental concentrations of compounds from each group in water, biota, and sediment are given to demonstrate representative values for comparison with concentrations determined during ongoing research. Finally, where data are sufficient, regional and temporal contamination trends in the United States are discussed.

Volatile metabolites of higher plant crops as a photosynthesizing life support system component under temperature stress at different light intensities

NASA Astrophysics Data System (ADS)

Gitelson, I. I.; Tikhomirov, A. A.; Parshina, O. V.; Ushakova, S. A.; Kalacheva, G. S.

The effect of elevated temperatures of 35 and 45°C (at the intensities of photosynthetically active radiation 322, 690 and 1104 μmol·m -2·s -1) on the photosynthesis, respiration, and qualitative and quantitative composition of the volatiles emitted by wheat ( Triticum aestuvi L., cultivar 232) crops was investigated in growth chambers. Identification and quantification of more than 20 volatile compounds (terpenoids-α-pinene, Δ3 carene, limonene, benzene, α-and trans-caryophyllene, α- and γ-terpinene, their derivatives, aromatic hydrocarbons, etc.) were conducted by gas chromatograph/mass spectrometry. Under light intensity of 1104 μmol·m -2·s -1 heat resistance of photosynthesis and respiration increased at 35°C and decreased at 45°C. The action of elevated temperatures brought about variations in the rate and direction of the synthesis of volatile metabolites. The emission of volatile compounds was the greatest under a reduced irradiation of 322 μmol·m -2·s -1 and the smallest under 1104 μmol·m -2·s -1, at 35°C. During the repair period, the contents and proportions of volatile compounds were different from their initial values, too. The degree of disruption and the following recovery of the functional state depended on the light intensity during the exposure to elevated temperatures. The investigation of the atmosphere of the growth chamber without plants has revaled the substances that were definitely technogenic in origin: tetramethylurea, dimethylsulfide, dibutylsulfide, dibutylphthalate, and a number of components of furan and silane nature.

Short communication: The effect of liquid storage on the flavor of whey protein concentrate.

PubMed

Park, Curtis W; Parker, Megan; Drake, MaryAnne

2016-06-01

Unit operations in dried dairy ingredient manufacture significantly influence sensory properties and, consequently, their use and consumer acceptance in a variety of ingredient applications. In whey protein concentrate (WPC) manufacture, liquid can be stored as whey or WPC before spray drying. The objective of this study was to determine the effect of storage, composition, and bleaching on the flavor of spray-dried WPC80. Liquid whey was manufactured and subjected to the following treatments: bleached or unbleached and liquid whey or liquid WPC storage. The experiment was replicated 3 times and included a no-storage control. All liquid storage was performed at 4°C for 24h. Flavor of the final spray-dried WPC80 was evaluated by a trained panel and volatile compound analyses. Storage of liquids increased cardboard flavor, decreased sweet aromatic flavor, and resulted in increased volatile lipid oxidation products. Bleaching altered the effect of liquid storage. Storage of unbleached liquid whey decreased sweet aromatic flavor and increased cardboard flavor and volatile lipid oxidation products compared with liquid WPC80 and no storage. In contrast, storage of bleached liquid WPC decreased sweet aromatic flavor and increased cardboard flavor and associated volatile lipid oxidation products compared with bleached liquid whey or no storage. These results confirm that liquid storage increases off-flavors in spray-dried protein but to a variable degree, depending on whether bleaching has been applied. If liquid storage is necessary, bleached WPC80 should be stored as liquid whey and unbleached WPC80 should be stored as liquid WPC to mitigate off-flavors. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Temporal trends and identification of the sources of volatile organic compounds in coastal seawater.

PubMed

Bravo-Linares, Claudio M; Mudge, Stephen M

2009-03-01

Volatile Organic Compounds (VOCs) in the marine environment are produced by biogenic sources (marine macroalgae, phytoplankton, sediments, etc.) as well from anthropogenic sources. The temporal variation of such VOCs was studied together with their relationship to biological, meteorological and physico-chemical factors. Sixty four different VOCs were quantified including halogenated (

Himalayan Aromatic Medicinal Plants: A Review of their Ethnopharmacology, Volatile Phytochemistry, and Biological Activities

PubMed Central

Joshi, Rakesh K.; Satyal, Prabodh; Setzer, Wiliam N.

2016-01-01

Aromatic plants have played key roles in the lives of tribal peoples living in the Himalaya by providing products for both food and medicine. This review presents a summary of aromatic medicinal plants from the Indian Himalaya, Nepal, and Bhutan, focusing on plant species for which volatile compositions have been described. The review summarizes 116 aromatic plant species distributed over 26 families. PMID:28930116

Biotransformation and biodegradation of selected nitroaromatics under anaerobic conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Razo-Flores, E.; Lettinga, G.; Field, J.A.

The fate of four nitroaromatic compounds (5-nitrosalicylate, 5NSA; 4-nitrobenzoate, 4NBc; 2,4-dinitrotoluene, 2,4DNT; nitrobenzene, NB) was studied in 160 mL laboratory-scale upward-flow anaerobic sludge bed reactors supplied with a mixture of volatile fatty acids and/or glucose as electron donors. All the nitroaromatics were transformed stoichiometrically to their corresponding aromatic amines. After prolonged reactor operation, 5NSA and 4NBc were completely mineralized to CH[sub 4] and CO[sub 2], whereas 2,4DNT was partially transformed to a nonidentified and nondegradable metabolite. Batch nitro-reduction experiments indicated that the position of the nitro group in relation to the other substituents in the aromatic ring plays a keymore » role in the rate of the nitro-group reduction. The results obtained indicate that certain nitroaromatic compounds can be completely mineralized and serve as a carbon and energy source for anaerobic bacteria.« less

Ellagitannin content, volatile composition and sensory profile of wines from different countries matured in oak barrels subjected to different toasting methods.

PubMed

González-Centeno, M R; Chira, K; Teissedre, P-L

2016-11-01

Ellagitannins and aromatic compounds evolution in Cabernet Sauvignon wines macerated in oak barrels for a year was studied. Identical barrels with different toastings (medium toasting, medium toasting with watering, Noisette) were used in French, Italian and USA cellars. Ellagitannins increased by 84-96% with aging time, as did woody volatiles, by 86-91% in French wines and 23-35% in Italian wines, while fruity aroma compounds declined by 50-57% in the French and Italian wines over a 12-months period. Nevertheless, other behaviors and different kinetics rates for these compounds were observed depending on barrel toasting, wine matrix and their interactions. Perceived overall woody intensity was closely related to trans-whiskey lactone, guaiacol and vanillin, whereas astringency and bitterness were significantly linked to ellagitannins (p<0.05). This is the first study that evaluates the toasting effect on wines from different countries matured in the same oak barrels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Volatile Organic Compounds in the Atmosphere of the Botanical Garden of the City of Rio de Janeiro: A Preliminary Study.

PubMed

da Silva, Cleyton Martins; Souza, Elaine Cesar C A; da Silva, Luane Lima; Oliveira, Rafael Lopes; Corrêa, Sergio Machado; Arbilla, Graciela

2016-11-01

Volatile organic compounds (VOCs) play a central role in atmospheric chemistry. In this work, VOCs in the Botanical Garden of Rio de Janeiro were determined using the TO-15 Method. The park occupies 1,370,000 m 2 in the southern area of the city and is next to the Tijuca Forest, which is considered the largest secondary urban forest in the world. The total VOC concentrations ranged from 43.52 to 168.75 µg m -3 , depending on the sampling site and dates. In terms of concentration isoprene represented 4 %-14 % of the total VOC masses. The results suggested that the differences in biomass, distance from the street and activities within the park affected the concentrations of VOCs. The ratios of isoprene/aromatic compounds were higher than those determined in other areas of the city, confirming that the atmosphere of this green area has the contribution of other sources. Kinetic and mechanistic reactivities were also evaluated.

Search for Chemical Biomarkers on Mars Using the Sample Analysis at Mars Instrument Suite on the Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Glavin, D. P.; Conrad, P.; Dworkin, J. P.; Eigenbrode, J.; Mahaffy, P. R.

2011-01-01

One key goal for the future exploration of Mars is the search for chemical biomarkers including complex organic compounds important in life on Earth. The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) will provide the most sensitive measurements of the organic composition of rocks and regolith samples ever carried out in situ on Mars. SAM consists of a gas chromatograph (GC), quadrupole mass spectrometer (QMS), and tunable laser spectrometer to measure volatiles in the atmosphere and released from rock powders heated up to 1000 C. The measurement of organics in solid samples will be accomplished by three experiments: (1) pyrolysis QMS to identify alkane fragments and simple aromatic compounds; pyrolysis GCMS to separate and identify complex mixtures of larger hydrocarbons; and (3) chemical derivatization and GCMS extract less volatile compounds including amino and carboxylic acids that are not detectable by the other two experiments.

Environmental Pollutant Benzo[a]Pyrene Impacts the Volatile Metabolome and Transcriptome of the Human Gut Microbiota.

PubMed

Defois, Clémence; Ratel, Jérémy; Denis, Sylvain; Batut, Bérénice; Beugnot, Réjane; Peyretaillade, Eric; Engel, Erwan; Peyret, Pierre

2017-01-01

Benzo[ a ]pyrene (B[ a ]P) is a ubiquitous, persistent, and carcinogenic pollutant that belongs to the large family of polycyclic aromatic hydrocarbons. Population exposure primarily occurs via contaminated food products, which introduces the pollutant to the digestive tract. Although the metabolism of B[ a ]P by host cells is well known, its impacts on the human gut microbiota, which plays a key role in health and disease, remain unexplored. We performed an in vitro assay using 16S barcoding, metatranscriptomics and volatile metabolomics to study the impact of B[ a ]P on two distinct human fecal microbiota. B[ a ]P exposure did not induce a significant change in the microbial structure; however, it altered the microbial volatolome in a dose-dependent manner. The transcript levels related to several metabolic pathways, such as vitamin and cofactor metabolism, cell wall compound metabolism, DNA repair and replication systems, and aromatic compound metabolism, were upregulated, whereas the transcript levels related to the glycolysis-gluconeogenesis pathway and bacterial chemotaxis toward simple carbohydrates were downregulated. These primary findings show that food pollutants, such as B[ a ]P, alter human gut microbiota activity. The observed shift in the volatolome demonstrates that B[ a ]P induces a specific deviation in the microbial metabolism.

Environmental Pollutant Benzo[a]Pyrene Impacts the Volatile Metabolome and Transcriptome of the Human Gut Microbiota

PubMed Central

Defois, Clémence; Ratel, Jérémy; Denis, Sylvain; Batut, Bérénice; Beugnot, Réjane; Peyretaillade, Eric; Engel, Erwan; Peyret, Pierre

2017-01-01

Benzo[a]pyrene (B[a]P) is a ubiquitous, persistent, and carcinogenic pollutant that belongs to the large family of polycyclic aromatic hydrocarbons. Population exposure primarily occurs via contaminated food products, which introduces the pollutant to the digestive tract. Although the metabolism of B[a]P by host cells is well known, its impacts on the human gut microbiota, which plays a key role in health and disease, remain unexplored. We performed an in vitro assay using 16S barcoding, metatranscriptomics and volatile metabolomics to study the impact of B[a]P on two distinct human fecal microbiota. B[a]P exposure did not induce a significant change in the microbial structure; however, it altered the microbial volatolome in a dose-dependent manner. The transcript levels related to several metabolic pathways, such as vitamin and cofactor metabolism, cell wall compound metabolism, DNA repair and replication systems, and aromatic compound metabolism, were upregulated, whereas the transcript levels related to the glycolysis-gluconeogenesis pathway and bacterial chemotaxis toward simple carbohydrates were downregulated. These primary findings show that food pollutants, such as B[a]P, alter human gut microbiota activity. The observed shift in the volatolome demonstrates that B[a]P induces a specific deviation in the microbial metabolism. PMID:28861070

Source profiles of volatile organic compounds associated with solvent use in Beijing, China

NASA Astrophysics Data System (ADS)

Yuan, Bin; Shao, Min; Lu, Sihua; Wang, Bin

2010-05-01

Compositions of volatile organic compound (VOC) emissions from painting applications and printing processes were sampled and measured by gas chromatography-mass spectrometry/flame ionization detection (GC-MS/FID) in Beijing. Toluene and C8 aromatics were the most abundant species, accounting for 76% of the total VOCs emitted from paint applications. The major species in printing emissions included heavier alkanes and aromatics, such as n-nonane, n-decane, n-undecane, toluene, and m/p-xylene. Measurements of VOCs obtained from furniture paint emissions in 2003 and 2007 suggest a quick decline in benzene levels associated with formulation changes in furniture paints during these years. A comparison of VOC source profiles for painting and printing between Beijing and other parts of the world showed significant region-specific discrepancies, probably because of different market demands and environmental standards. We conducted the evaluation of the source reactivities for various VOC emission sources. The ozone formation potential (OFP) for unit mass of VOCs source emissions is the highest for paint applications. Substituting solvent-based paints by water-based in Beijing will lead to an OFP reduction of 152,000 tons per year, which is more than 1/4 of the OFPs for VOCs emissions from vehicle exhaust in the city.

Laboratory measurements of emission factors of nonmethane volatile organic compounds from burning of Chinese crop residues

NASA Astrophysics Data System (ADS)

Inomata, Satoshi; Tanimoto, Hiroshi; Pan, Xiaole; Taketani, Fumikazu; Komazaki, Yuichi; Miyakawa, Takuma; Kanaya, Yugo; Wang, Zifa

2015-05-01

The emission factors (EFs) of nonmethane volatile organic compounds (NMVOCs) emitted during the burning of Chinese crop residue were investigated as a function of modified combustion efficiency in laboratory experiments. NMVOCs, including acetonitrile, aldehydes/ketones, furan, and aromatic hydrocarbons, were monitored by proton-transfer-reaction mass spectrometry. Rape plant was burned in dry conditions and wheat straw was burned in both wet and dry conditions to simulate the possible burning of damp crop residue in regions of high temperature and humidity. We compared the present data to field data reported by Kudo et al. (2014). Good agreement between field and laboratory data was obtained for aromatics under relatively more smoldering combustion of dry samples, but laboratory data were slightly overestimated compared to field data for oxygenated VOC (OVOC). When EFs from the burning of wet samples were investigated, the consistency between the field and laboratory data for OVOCs was stronger than for dry samples. This may be caused by residual moisture in crop residue that has been stockpiled in humid regions. Comparison of the wet laboratory data with field data suggests that Kudo et al. (2014) observed the biomass burning plumes under relatively more smoldering conditions in which approximately a few tens of percentages of burned fuel materials were wet.

Farmed and wild sea bass (Dicentrarchus labrax) volatile metabolites: a comparative study by SPME-GC/MS.

PubMed

Vidal, Natalia P; Manzanos, María J; Goicoechea, Encarnación; Guillén, María D

2016-03-15

Farmed and wild European sea bass (Dicentrarchus labrax) could be distinguished by its volatile metabolites, an issue not addressed until now. The aim of this work was to study these metabolites by solid-phase microextraction followed by gas chromatography/mass spectrometry (SPME-GC/MS). Both farmed and wild sea bass have a great number of volatile metabolites, most of them being in low concentrations. These include alcohols, aldehydes, ketones, alkylfurans, acids, aliphatic and aromatic hydrocarbons, terpenes, sulfur and nitrogen derivatives, 2,6-di-tert-butyl-4-methylphenol and one derived compound, as well as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, this latter compound presumably resulting from environmental contamination. Important differences have been detected between both types of sea bass, and also among individuals inside each group. Farmed specimens are richer in volatile metabolites than the wild counterparts; however, these latter, in general, contain a high number and abundance of metabolites resulting from microbial and enzymatic non-oxidative activity than the former. Clear differences in the volatile metabolites of wild and farmed sea bass have been found. A great deal of valuable information on sea bass volatile metabolites has been obtained, which can be useful in understanding certain aspects of the quality and safety of raw and processed sea bass. © 2015 Society of Chemical Industry.

Fennel (Foeniculum vulgare Mill. subsp. piperitum) florets, a traditional culinary spice in Italy: evaluation of phenolics and volatiles in local populations, and comparison with the composition of other plant parts.

PubMed

Ferioli, Federico; Giambanelli, Elisa; D'Antuono, L Filippo

2017-12-01

Wild fennel (Foeniculum vulgare Mill. subsp. piperitum) florets are used as a typical spice in central and southern Italy. Although fennel (Foeniculum vulgare Mill.), belonging to the Apiaceae (syn. Umbelliferae) family, is a well-known vegetable and aromatic plant, whose main phytochemical compounds have been extensively analysed and investigated as flavouring agents and for their putative health promoting functions, its florets have not been specifically considered up to now. Therefore, the volatile and phenolic composition of florets from an Italian wild fennel crop was determined at different developmental stages, and compared to that of leaves and fruits. Moreover, florets of nine Italian wild fennel populations of different geographical origin from northern-central Italy were also analysed. The total phenolic amount increased from leaves to florets, reaching its highest value in early florets, at 58 012 mg kg -1 of dry matter (DM), then constantly decreased in fruits. In florets of wild populations, phenolics ranged from 6666 to 43 368 mg kg -1 DM. The total amount of volatile compounds was more than twice higher in florets (21 449 mg kg -1 DM) than in leaves (10 470 mg kg -1 DM), reaching its highest value in fruits (50 533 mg kg -1 DM). Estragole and trans-anethole were the main compounds of the volatile fraction. Total volatiles ranged from 24 367 to 60 468 mg kg -1 DM in florets of local populations. Significant changes in the total amount and profile of both phenolic and volatile compounds occurred during plant development. The consistent increase of estragole at later developmental stages supported the claim of different sensory properties of florets and fruits. Geographical origin significantly affected phenolic and volatile composition of wild fennel florets. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Volatile organic compounds and particulates as components of diesel engine exhaust gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulz, H.; Bandeira de Melo, G.; Ousmanov, F.

1999-07-01

Volatile organic compounds (VOC) and soot particles have been determined in a Diesel`s exhaust gas. A new sampling method allowed the measurement of emissions of organic compounds (C{sub 1} to C{sub 20}) in a gas chromatogram at a detection limit of ca. 0.2 mg/m{sup 3}. Particles were collected with a filter bed of ceramic particles and characterized by temperature programmed desorption (TPD) and oxidation (TPO). Engine runs were always performed at a fixed and constant air to fuel equivalence ratio ({lambda}) and with a constant volumetric efficiency, because these parameters strongly influenced the emissions in terms of both composition andmore » order of magnitude. The effective combustion temperature again strongly governed the nature of the emissions. Model fuels, composed of individual paraffins and aromatics and additions of sulfur compounds and an organic nitrate (for cetane number enhancement) were used. The results contribute to the understanding of the origin of specific emissions from Diesel engines. These newly developed methods are recommended for further application.« less

Catalytic oxidation of volatile organic compounds (VOCs) - A review

NASA Astrophysics Data System (ADS)

Kamal, Muhammad Shahzad; Razzak, Shaikh A.; Hossain, Mohammad M.

2016-09-01

Emission of volatile organic compounds (VOCs) is one of the major contributors to air pollution. The main sources of VOCs are petroleum refineries, fuel combustions, chemical industries, decomposition in the biosphere and biomass, pharmaceutical plants, automobile industries, textile manufacturers, solvents processes, cleaning products, printing presses, insulating materials, office supplies, printers etc. The most common VOCs are halogenated compounds, aldehydes, alcohols, ketones, aromatic compounds, and ethers. High concentrations of these VOCs can cause irritations, nausea, dizziness, and headaches. Some VOCs are also carcinogenic for both humans and animals. Therefore, it is crucial to minimize the emission of VOCs. Among the available technologies, the catalytic oxidation of VOCs is the most popular because of its versatility of handling a range of organic emissions under mild operating conditions. Due to that fact, there are numerous research initiatives focused on developing advanced technologies for the catalytic destruction of VOCs. This review discusses recent developments in catalytic systems for the destruction of VOCs. Review also describes various VOCs and their sources of emission, mechanisms of catalytic destruction, the causes of catalyst deactivation, and catalyst regeneration methods.

A multi-residue method for characterization of endocrine disruptors in gaseous and particulate phases of ambient air

NASA Astrophysics Data System (ADS)

Alliot, Fabrice; Moreau-Guigon, Elodie; Bourges, Catherine; Desportes, Annie; Teil, Marie-Jeanne; Blanchard, Martine; Chevreuil, Marc

2014-08-01

A number of semi-volatile compounds occur in indoor air most of them being considered as potent endocrine disruptors and thus, exerting a possible impact upon health. To assess their concentration levels in indoor air, we developed and validated a method for sampling and multi-residue analysis of 58 compounds including phthalates, polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), parabens, bisphenol A (BPA) and tetrabromobisphenol A (TBBPA) in gaseous and particulate phases of air. We validated each step of procedures from extraction until analysis. Matrice spiking were performed at extraction, fractionation and purification stages. The more volatile compounds were analyzed with a gas chromatography system coupled with a mass spectrometer (GC/MS) or with a tandem mass spectrometer (GC/MS/MS). The less volatile compounds were analyzed with a liquid chromatography system coupled with a tandem mass spectrometer (LC/MS/MS). Labeled internal standard method was used ensuring high quantification accuracy. The instrumental detection limits were under 1 pg for all compounds and therefore, a limit of quantification averaging 1 pg m-3 for the gaseous and the particulate phases and a volume of 150 m3, except for phthalates, phenol compounds and BDE-209. Satisfactory recoveries were found except for phenol compounds. That method was successfully applied to several indoor air samples (office, apartment and day nursery) and most of the targeted compounds were quantified, mainly occurring in the gaseous phase. The most abundant were phthalates (up to 918 ng m-3 in total air), followed by PCBs > parabens > BPA > PAHs > PBDEs.

Compound Specific Concentration and Stable Isotope Ratio Measurements of Atmospheric Particulate Organic Matter and Gas Phase Nitrophenols

NASA Astrophysics Data System (ADS)

Busca, R.; Saccon, M.; Moukhtar, S.; Rudolph, J.

2009-05-01

Atmospheric particulate organic matter (POM) adversely affects health and climate. One of the still poorly understood sources of secondary organic matter (SOM) is the formation of secondary POM from the photo- oxidation of atmospheric volatile organic compounds (VOC). Nitrophenols, which are toxic semi-volatile compounds, are formed in the atmosphere by OH-radical initiated photo-oxidation of aromatic hydrocarbons, such as toluene. A method was developed to determine concentrations and stable carbon isotope ratios of particulate methyl nitrophenols in the atmosphere. This method has been used to quantify methyl nitrophenols, specifically 2-methyl-4-nitrophenol and 4-methyl-2-nitrophenol, found in atmospheric PM samples in trace quantities. Using this method, we conducted measurements of methyl nitrophenols in atmospheric PM in rural and suburban areas in Southern Ontario. The results of these measurements showed that the concentration of methyl nitrophenols in atmospheric PM is much lower than expected from the extrapolation of laboratory experiments and measured atmospheric toluene concentrations. In order to better understand the reasons for these findings, an analytical method for the analysis of nitrophenols in the gas phase is currently being developed. Similarly, the measurement technique is modified to allow analysis of other phenolic products of the oxidation of aromatic hydrocarbons in PM as well as in the gas phase. In this poster, sampling techniques for collection and GC-MS analysis of nitrophenols in gas phase and PM will be presented along with preliminary results from summer 2008 and spring 2009 studies.

Wine aromatic compound production and fermentative behaviour within different non-Saccharomyces species and clones.

PubMed

Escribano, R; González-Arenzana, L; Portu, J; Garijo, P; López-Alfaro, I; López, R; Santamaría, P; Gutiérrez, A R

2018-06-01

Twenty-five enological yeasts belonging to nine different species (Candida zeylanoides, Cryptococcus uzbekistanensis, Debaryomyces hansenii, Lachancea thermotolerans, Metschnikowia pulcherrima, Torulaspora delbrueckii, Williopsis pratensis, Zygosaccharomyces bailii and Saccharomyces cerevisiae) were screened for aroma formation and fermentative behaviour as part of a non-Saccharomyces yeast selection programme. Pure cultures were inoculated in pasteurized grape juice in order to perform alcoholic fermentations. Some non-Saccharomyces species did not ferment, others did not get established and none of them completed alcoholic fermentations. The physico-chemical parameters of the wines and the abundance of aromatic compounds at the end of alcoholic fermentation highlighted the notable differences in the aroma-forming ability and fermentative behaviour of the different non-Saccharomyces species, but not within clones. Lower diversity was detected within non-Saccharomyces species than that reported in S. cerevisiae with regard to enological behaviour and aromatic profiles. Metschnikowia pulcherrima and L. thermotolerans are the two species with higher possibilities to become an inoculum. Few significant differences were found within clones of the same species, but very important parameters in wine quality, such as volatile acidity, ethyl acetate and acetoin, which would justify selection programmes within those species. The results also demonstrated that T. delbrueckii and L. thermotolerans are two close species in their aromatic profiles. © 2018 The Society for Applied Microbiology.

Molecular characterization of nitrogen and sulfur containing compounds in night-time SOA

NASA Astrophysics Data System (ADS)

Iinuma, Yoshiteru; Mutzel, Anke; Rodigast, Maria; Böge, Olaf; Herrmann, Hartmut

2014-05-01

The oxidation of volatile organic compounds (VOCs) leads to the formation of low volatile organic compounds that can form secondary organic aerosol (SOA). Studies in the past showed that laboratory generated and ambient SOA are made of polar molecules with O/C ratios generally greater than 0.5. More recent studies have shown that SOA compounds can contain heteroatoms mainly sulfur and nitrogen atoms. Offline chemical analysis with high-resolution mass spectrometers and fragmentation experiments has shown that sulphur containing compounds are mainly organosulfates and nitrogen containing species are aromatic heterocyclic compounds such as imidazole and nitrated aromatic compounds such as nitrophenols. In addition to these, SOA compounds containing both sulfur and nitrogen have been reported from the analysis of ambient organic aerosol, rainwater, fog and cloud samples. Based on the mass spectrometric evidence these compounds are attributed to nitrooxy-organosulfates originating from isoprene and monoterpenes. Although these compounds are ubiquitously detected in the ambient samples, reports about their detection in laboratory generated SOA are scares and their formation mechanisms are not well understood. In the present study, we investigated the formation of sulfur and nitrogen containing SOA species in the oxidation of biogenic VOCs. Photooxidation and night-time oxidation experiments were performed in a smog chamber to produce SOA samples. The laboratory generated SOA samples were analysed with UPLC-IMS-TOFMS (Ultra Performance Liquid Chromatography coupled to Ion Mobility Spectrometry and Time of Flight Mass Spectrometry). The presence of highly acidic sulphate seed particles (pH0) did not promote the formation of compounds with chemical formula of C10H17NO7S- and m/z value of 294.0653, indicating that the formation mechanisms of these compounds unlikely involve the ring opening reactions of epoxides and subsequent sulfation reactions. On the other hand, their formation was significantly enhanced when the night-time oxidation was performed in the presence of both neutral seed particle and gas-phase SO2, suggesting that the presence of gas-phase SO2 is a key for their formation.

Health assessment for Lang Property National Priorities List (NPL) site, Pemberton Township, Burlington County, New Jersey, Region 2. CERCLIS No. NJD980505382. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1989-04-17

The Lang Property National Priorities List Site is located in Pemberton Township, Burlington County, New Jersey. Unauthorized disposal of hazardous wastes occurred on approximately two acres of the 40-acre site. The contaminant classes that were identified on the site are volatile organic compounds (VOCs), semi-volatile organic compounds (semi-VOCs), polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, and metals. The contaminant classes of concern are PCBs, VOCs, and semi-VOCs for on-site ground water. VOCs is the contaminant class of concern for sediments and surface water. The on-site ground water is highly contaminated; at the maximum chemical concentrations detected, use of thismore » water without treatment would pose a human health concern. The potential does exist for human exposure to ground water contaminants by ingestion, inhalation of volatilized VOCs from ground water, and dermal absorption. The surface soils are also highly contaminated and represent a current possible as well as future human health concern for trespassers, blueberry farm workers and harvesters, and construction and remedial workers.« less

Effect of Raw Material, Pressing and Glycosidase on the Volatile Compound Composition of Wine Made From Goji Berries.

PubMed

Yuan, Guanshen; Ren, Jie; Ouyang, Xiaoyu; Wang, Liying; Wang, Mengze; Shen, Xiaodong; Zhang, Bolin; Zhu, Baoqing

2016-10-02

This study investigated the effect of raw material, pressing, and glycosidase on the aromatic profile of goji berry wine. The free-run and the pressed juice of dried and fresh goji berries were used for wine production, whereas glycosidase was applied to wine after fermentation. Dried goji berry fermented wine exhibited much stronger fruity, floral, caramel, and herbaceous odors due to higher levels of esters, β-ionone and methionol. However, fresh berry fermented wine possessed stronger chemical notes due to higher levels of 4-ethylphenol. Pressing treatment reduced the fruity and caramel odors in these fermented wines, and fresh berry free-run juice fermented wine exhibited the least floral aroma. Glycosidase addition did not alter the aromatic composition of wines. The principal component analysis indicated that goji raw material played a primary role in differentiating the aromatic profiles of the wines due to the difference on the content of 20 esters, nine benzenes, eight aldehydes/ketones, three acids, two alcohols and six other volatiles. The content differences on isopentyl alcohol, styrene, benzyl alcohol, 1-octanol, ( E )-5-decen-1-ol, 1-hexanol, and β-cyclocitral resulted in the segregation of the wines with and without the pressing treatment, especially for fresh berry fermented wine.

High-field FT-ICR-MS and aromaticity equivalent approach for structural identification of water soluble organic compounds (WSOC)

NASA Astrophysics Data System (ADS)

Harir, Mourad; Yassine, Mahmoud M.; Dabek-Zlotorzynska, Ewa; Hertkorn, Norbert; Schmitt-Kopplin, Philippe

2015-04-01

Organic aerosol (OA) makes up a large and often dominant fraction, (20 to 90%) of the submicron atmospheric particulate mass, and its effects are becoming increasingly important in determining climatic and health effects of atmospheric aerosols. Despite the abundance of OA, our understanding of the sources, formation processes and atmospheric properties of OA is limited. Atmospheric OA has both primary (directly emitted) and secondary (formed in the atmosphere from precursor gases) sources, which can be natural (e.g. vegetation) and/or anthropogenic (e.g. fossil-based vehicle exhaust or biomass burning). A significant fraction of OA contains as much as 20-70% of water soluble organic compounds (WSOC). The WSOC fraction is a very complex mixture of low volatility, polyfunctional aliphatic and aromatic compounds containing carboxyl, alcohol, carbonyl, sulfo, nitro, and other functionalities. This high degree of chemical complexity of atmospheric organics has inspired a number of sophisticated approaches that are capable of identifying and detecting a variety of different analytes in OA. Accordingly, one of the most challenging areas of atmospheric particulate matter (PM) analysis is to comprehend the molecular complexity of the OA, especially WSOC fraction, a significant component of atmospheric fine PM (PM2.5). The sources of WSOC are not well understood, especially the relative contributions of primary vs. secondary organic aerosol. Therefore, the molecular characterization of WSOC is important because it allows gaining insight into aerosol sources and underlying mechanisms of secondary organic aerosols (SOA) formation and transformation. In this abstract, molecular characterization of WSOC was achieved using high-field mass spectrometry FT-ICR-MS and aromaticity equivalent approach. Aromaticity equivalent (Xc), defined recently as a new parameter calculated from the assigned molecular formulas (complementary to the aromaticity index [1]), is introduced to improve identification and characterization of aromatic and condensed aromatic compounds in WSOC [2]. We proposed threshold values of Xc≥ 2.5000 and Xc≥ 2.7143 as ambiguous minimum criteria for the presence of aromatic structure and condensed aromatic compounds, respectively. The advantage of employing this parameter is that Xc would have a constant value for each proposed core structure regardless the degree of alkylation, and thus visual representation and structural interpretations of the spectra become advantageous for characterizing and comparing complex samples. Diesel particulate matter (DPM) and two atmospheric aerosols collected in the industrial area affected by biomass burning events were used to study the applicability of the proposed criteria for the improved identification of aromatic and condensed aromatic structures in complex mixtures in the FT-ICR mass spectra. References [1] Koch.BP, Dittmar.T. From mass to structure: an aromaticity index for high-resolution mass data of natural organic matter. Rapid Commun. Mass Spectrom. 2006, 20, 926-932 [2] Yassine.MM, Harir.M, Dabek-Zlotorzynska.E, Schmitt-Kopplin.Ph. Structural characterization of organic aerosol using Fourier transform ion cyclotron resonance mass spectrometry: Aromaticity equivalent approach. Rapid Commun. Mass Spectrom. 2014. 28. 2445-2454

Optimisation of solid-phase microextraction combined with gas chromatography-mass spectrometry based methodology to establish the global volatile signature in pulp and skin of Vitis vinifera L. grape varieties.

PubMed

Perestrelo, Rosa; Barros, António S; Rocha, Sílvia M; Câmara, José S

2011-09-15

The volatiles (VOCs) and semi-volatile organic compounds (SVOCs) responsible for aroma are mainly present in skin of grape varieties. Thus, the present investigation is directed towards the optimisation of a solvent free methodology based on headspace-solid-phase microextraction (HS-SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-qMS) in order to establish the global volatile composition in pulp and skin of Bual and Bastardo Vitis vinifera L. varieties. A deep study on the extraction-influencing parameters was performed, and the best results, expressed as GC peak area, number of identified compounds and reproducibility, were obtained using 4 g of sample homogenised in 5 mL of ultra-pure Milli-Q water in a 20 mL glass vial with addition of 2g of sodium chloride (NaCl). A divinylbenzene/carboxen/polydimethylsiloxane fibre was selected for extraction at 60°C for 45 min under continuous stirring at 800 rpm. More than 100 VOCs and SVOCs, including 27 monoterpenoids, 27 sesquiterpenoids, 21 carbonyl compounds, 17 alcohols (from which 2 aromatics), 10 C(13) norisoprenoids and 5 acids were identified. The results showed that, for both grape varieties, the levels and number of volatiles in skin were considerably higher than those observed in pulp. According to the data obtained by principal component analysis (PCA), the establishment of the global volatile signature of grape and the relationship between different part of grapes-pulp and skin, may be an useful tool to winemaker decision to define the vinification procedures that improves the organoleptic characteristics of the corresponding wines and consequently contributed to an economic valorization and consumer acceptance. Copyright © 2011 Elsevier B.V. All rights reserved.

Changes on physico-chemical, textural, lipolysis and volatile compounds during the manufacture of dry-cured foal "cecina".

PubMed

Lorenzo, José M

2014-01-01

The changes in the physico-chemical and textural properties, lipolysis and volatile compounds during the manufacture of dry-cured foal "cecina" were studied. The pH increased during the last stages of processing but gradually declined over the curing period. TBARS values, hardness and chewiness increased with processing time from 0.14, 2.74 and 0.83 to 3.49 mg malonaldehyde/kg, 20.33 kg and 5.05 kg∗mm, respectively. Ripening time also affected the colour parameters: lightness (L*), redness (a*) and yellowness (b*) (P<0.001). The total average content of free fatty acid (FFA) increased significantly from 433.7 mg/100 g of fat in the raw pieces to 2655.5 mg/100 g of fat at the end of the drying-ripening stage. The main FFA at the end of the manufacturing process was palmitic acid (C16:0), followed by oleic (C18:1cis9), stearic (C18:0) and linoleic (C18:2n-6). A total of fifty five volatile compounds were identified during the manufacture of dry-cured foal "cecina", including esters, aldehydes, aliphatic hydrocarbons, branched hydrocarbons, alcohols, aromatic hydrocarbons, furans, ketones. Aldehydes reached their maximum level at the end of the post-salting stage. In the final product, esters became the dominant chemical compounds. © 2013.

Native Fluorescence Detection Methods and Detectors for Naphthalene and/or Other Volatile Organic Compound Vapors

NASA Technical Reports Server (NTRS)

Hug, William F. (Inventor); Bhartia, Rohit (Inventor); Reid, Ray D. (Inventor); Lane, Arthur L. (Inventor)

2014-01-01

Naphthalene, benzene, toluene, xylene, and other volatile organic compounds have been identified as serious health hazards. This is especially true for personnel working with JP8 jet fuel and other fuels containing naphthalene as well as other hazardous volatile organic compounds (VOCs). Embodiments of the invention are directed to methods and apparatus for near-real-time in-situ detection and accumulated dose measurement of exposure to naphthalene vapor and other hazardous gaseous VOCs. The methods and apparatus employ excitation of fluorophors native or endogenous to compounds of interest using light sources emitting in the ultraviolet below 300 nm and measurement of native fluorescence emissions in distinct wavebands above the excitation wavelength. The apparatus of some embodiments are cell-phone-sized sensor/dosimeter "badges" to be worn by personnel potentially exposed to naphthalene or other hazardous VOCs. The badge sensor of some embodiments provides both real time detection and data logging of exposure to naphthalene or other VOCs of interest from which both instantaneous and accumulated dose can be determined. The badges employ a new native fluorescence based detection method to identify and differentiate VOCs. The particular focus of some embodiments are the detection and identification of naphthalene while other embodiments are directed to detection and identification of other VOCs like aromatic hydrocarbons such as benzene, toluene, and xylene.

Measurement of in-vehicle volatile organic compounds under static conditions.

PubMed

You, Ke-wei; Ge, Yun-shan; Hu, Bin; Ning, Zhan-wu; Zhao, Shou-tang; Zhang, Yan-ni; Xie, Peng

2007-01-01

The types and quantities of volatile organic compounds (VOCs) inside vehicles have been determined in one new vehicle and two old vehicles under static conditions using the Thermodesorber-Gas Chromatograph/Mass Spectrometer (TD-GC/MS). Air sampling and analysis was conducted under the requirement of USEPA Method TO-17. A room-size, environment test chamber was utilized to provide stable and accurate control of the required environmental conditions (temperature, humidity, horizontal and vertical airflow velocity, and background VOCs concentration). Static vehicle testing demonstrated that although the amount of total volatile organic compounds (TVOC) detected within each vehicle was relatively distinct (4940 microg/m3 in the new vehicle A, 1240 microg/m3 in used vehicle B, and 132 microg/m3 in used vehicle C), toluene, xylene, some aromatic compounds, and various C7-C12 alkanes were among the predominant VOC species in all three vehicles tested. In addition, tetramethyl succinonitrile, possibly derived from foam cushions was detected in vehicle B. The types and quantities of VOCs varied considerably according to various kinds of factors, such as, vehicle age, vehicle model, temperature, air exchange rate, and environment airflow velocity. For example, if the airflow velocity increases from 0.1 m/s to 0.7 m/s, the vehicle's air exchange rate increases from 0.15 h(-1) to 0.67 h(-1), and in-vehicle TVOC concentration decreases from 1780 to 1201 microg/m3.

Using chromatography – desorption method of manufacturing gas mixtures for analytical instruments calibration

NASA Astrophysics Data System (ADS)

Platonov, I. A.; Kolesnichenko, I. N.; Lange, P. K.

2018-05-01

In this paper, the chromatography desorption method of obtaining gas mixtures of known compositions stable for a time sufficient to calibrate analytical instruments is considered. The comparative analysis results of the preparation accuracy of gas mixtures with volatile organic compounds using diffusion, polyabarbotage and chromatography desorption methods are presented. It is shown that the application of chromatography desorption devices allows one to obtain gas mixtures that are stable for 10...60 hours in a dynamic condition. These gas mixtures contain volatile aliphatic and aromatic hydrocarbons with a concentration error of no more than 7%. It is shown that it is expedient to use such gas mixtures for analytical instruments calibration (chromatographs, spectrophotometers, etc.)

Comparison of fortified, sfursat, and passito wines produced from fresh and dehydrated grapes of aromatic black cv. Moscato nero (Vitis vinifera L.).

PubMed

Ossola, Carolina; Giacosa, Simone; Torchio, Fabrizio; Río Segade, Susana; Caudana, Alberto; Cagnasso, Enzo; Gerbi, Vincenzo; Rolle, Luca

2017-08-01

Moscato nero d'Acqui is an Italian aromatic black winegrape variety characterized by a low content of anthocyanins (mostly tri-substituted), a satisfactory content of high molecular mass tannins, and a fair amount of terpenes. The grapes were subjected to a postharvest dehydration process under controlled thermohygrometric conditions (16-18°C, 55-70 RH%, 0.6m/s air speed) with the aim to produce three different special wine types (fortified, sfursat, and passito) from fresh, partially dehydrated (27°Brix), and withered (36°Brix) grapes, respectively. Chemical traits of produced grapes and wines were then evaluated through spectrophotometric, HPLC, and GC-MS methods. Increased contents of skin phenolic compounds and reduced extractable contents of seed phenolic compounds were observed as dehydration progressed. Few significant differences were found in the anthocyanin profile of grapes, although the relative abundance of coumaroylated anthocyanins was higher in dehydrated grapes. The predominant free volatile compound found in grapes was geraniol, which decreased with increasing water loss, whereas the contents of major glycosylated volatile compounds increased even above the concentration effect. The changes in the phenolic composition among wines agreed with those among grape skins. Fortified wines were chromatically unsatisfactory probably due to the low content of total anthocyanins, whereas sfursat and passito wines meet good chromatic characteristics as a result of the concentration effect during grape dehydration. Fortified and sfursat wines had free aroma profiles richer in 2-phenylethanol and citronellol, whereas passito wines were mainly composed of 2-phenylethanol and 2-phenylethyl acetate, citronellol being the predominant terpenol in all the wine types studied. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristics of volatile organic compounds (VOCs) from the evaporative emissions of modern passenger cars

NASA Astrophysics Data System (ADS)

Yue, Tingting; Yue, Xin; Chai, Fahe; Hu, Jingnan; Lai, Yitu; He, Liqang; Zhu, Rencheng

2017-02-01

Volatile organic compounds (VOCs) from vehicle evaporative emissions contribute substantially to photochemical air pollution. Yet, few studies of the characteristics of VOCs emitted from vehicle evaporative emissions have been published. We investigate the characteristics of 57 VOCs in hot soak, 24 h diurnal and 48 h diurnal emissions by applying the Sealed Housing Evaporative Determination unit (SHED) test to three modern passenger cars (one US Tier 2 and two China IV vehicles) using two different types of gasoline. The characteristics of the VOCs from the hot soak, 24 h diurnal and 48 h diurnal emissions were different due to their different emission mechanisms. In the hot soak emissions, toluene, isopentane/n-pentane, and 2,2,4-trimethylpentane were dominant species. In the 24 h and 48 h diurnal emissions, isopentane and n-pentane were dominant species. Toluene was the third most dominant component in the 24 h diurnal emissions but decreased by a mass of 42%-80% in the 48 h diurnal emissions. In the hot soak, 24 h diurnal and 48 h diurnal emissions, alkanes were generally the dominant hydrocarbons, followed by aromatics and olefins. However, owing to different evaporative emission mechanisms, the weight percentages of the aromatic hydrocarbons decreased and the weight percentages of the alkanes increased from the hot soak test to the 24 h diurnal and 48 h diurnal tests for each vehicle. The dominant contributors to the ozone formation potentials (OFPs) were also different in the hot soak, 24 h diurnal and 48 h diurnal emissions. The OFPs (g O3/g VOC) of the hot soak emissions were higher than those of the 24 h and 48 h diurnal emissions. In addition, the combined effect of decreasing the olefin and aromatic contents of gasoline on vehicle evaporative emissions was investigated. The aromatics all decreased substantially in the hot soak, 24 h and 48 h diurnal emissions, and the total masses of the VOCs and OFPs decreased, with the greatest reduction occurring in the hot soak emissions when the fuel aromatic and olefin contents were reduced.

Aromatic acids in a Eurasian Arctic ice core: a 2600-year proxy record of biomass burning

NASA Astrophysics Data System (ADS)

Grieman, Mackenzie M.; Aydin, Murat; Fritzsche, Diedrich; McConnell, Joseph R.; Opel, Thomas; Sigl, Michael; Saltzman, Eric S.

2017-04-01

Wildfires and their emissions have significant impacts on ecosystems, climate, atmospheric chemistry, and carbon cycling. Well-dated proxy records are needed to study the long-term climatic controls on biomass burning and the associated climate feedbacks. There is a particular lack of information about long-term biomass burning variations in Siberia, the largest forested area in the Northern Hemisphere. In this study we report analyses of aromatic acids (vanillic and para-hydroxybenzoic acids) over the past 2600 years in the Eurasian Arctic Akademii Nauk ice core. These compounds are aerosol-borne, semi-volatile organic compounds derived from lignin combustion. The analyses were made using ion chromatography with electrospray mass spectrometric detection. The levels of these aromatic acids ranged from below the detection limit (0.01 to 0.05 ppb; 1 ppb = 1000 ng L-1) to about 1 ppb, with roughly 30 % of the samples above the detection limit. In the preindustrial late Holocene, highly elevated aromatic acid levels are observed during three distinct periods (650-300 BCE, 340-660 CE, and 1460-1660 CE). The timing of the two most recent periods coincides with the episodic pulsing of ice-rafted debris in the North Atlantic known as Bond events and a weakened Asian monsoon, suggesting a link between fires and large-scale climate variability on millennial timescales. Aromatic acid levels also are elevated during the onset of the industrial period from 1780 to 1860 CE, but with a different ratio of vanillic and para-hydroxybenzoic acid than is observed during the preindustrial period. This study provides the first millennial-scale record of aromatic acids. This study clearly demonstrates that coherent aromatic acid signals are recorded in polar ice cores that can be used as proxies for past trends in biomass burning.

Characterisation of the volatile profile of coconut water from five varieties using an optimised HS-SPME-GC analysis.

PubMed

Prades, Alexia; Assa, Rebecca Rachel Ablan; Dornier, Manuel; Pain, Jean-Pierre; Boulanger, Renaud

2012-09-01

Coconut (Cocos nucifera L.) water is a refreshing tropical drink whose international market has recently been growing. However, little is yet known about its physicochemical composition, particularly its aroma. This study set out to characterise the volatile profile of water from five coconut varieties. Aroma compounds were characterised by headspace solid phase microextraction gas chromatography (HS-SPME-GC) analysis. An experimental design was established to optimise SPME conditions, leading to an equilibration time of 10 min followed by an extraction time of 60 min at 50 °C. Accordingly, immature coconut water from WAT (West African Tall), PB121 (MYD × WAT Hybrid), MYD (Malayan Yellow Dwarf), EGD (Equatorial Guinea Green Dwarf) and THD (Thailand Aromatic Green Dwarf) palms was analysed and described. Ketones were mainly present in the Tall and Hybrid varieties, whereas aldehydes were most abundant in the Dwarf palms. Tall coconut water was characterised by a high lactone content. THD exhibited a high ethyl octanoate level. The cluster analysis of the volatile fraction from the five coconut cultivars was found to be related to their genetic classification. The volatile compounds of immature coconut water from five varieties were characterised for the first time. Volatile profile analysis could be a useful tool for the selection of Dwarf coconut varieties, which are mainly consumed as a beverage. Copyright © 2012 Society of Chemical Industry.

Identification of Key Odorants in Used Disposable Absorbent Incontinence Products

PubMed Central

Hall, Gunnar; Forsgren-Brusk, Ulla

2017-01-01

PURPOSE: The purpose of this study was to identify key odorants in used disposable absorbent incontinence products. DESIGN: Descriptive in vitro study SUBJECTS AND SETTING: Samples of used incontinence products were collected from 8 residents with urinary incontinence living in geriatric nursing homes in the Gothenburg area of Sweden. Products were chosen from a larger set of products that had previously been characterized by descriptive odor analysis. METHODS: Pieces of the used incontinence products were cut from the wet area, placed in glass bottles, and kept frozen until dynamic headspace sampling of volatile compounds was completed. Gas chromatography–olfactometry was used to identify which compounds contributed most to the odors in the samples. Compounds were identified by gas chromatography–mass spectrometry. RESULTS: Twenty-eight volatiles were found to be key odorants in the used incontinence products. Twenty-six were successfully identified. They belonged to the following classes of chemical compounds: aldehydes (6); amines (1); aromatics (3); isothiocyanates (1); heterocyclics (2); ketones (6); sulfur compounds (6); and terpenes (1). CONCLUSION: Nine of the 28 key odorants were considered to be of particular importance to the odor of the used incontinence products: 3-methylbutanal, trimethylamine, cresol, guaiacol, 4,5-dimethylthiazole-S-oxide, diacetyl, dimethyl trisulfide, 5-methylthio-4-penten-2-ol, and an unidentified compound. PMID:28328644

Primary Emission and the Potential of Secondary Aerosol Formation from Chinese Gasoline Engine Exhaust

NASA Astrophysics Data System (ADS)

Hu, Min; Peng, Jianfei; Qin, Yanhong; Du, Zhuofei; Li, Mengjin; Zheng, Rong; Zheng, Jing; Shang, Dongjie; Lu, Sihua; Wu, Yusheng; Zeng, Limin; Guo, Song; Shao, Min; Wang, Yinhui; Shuai, Shijin

2017-04-01

Along with the urbanization and economic growth, vehicle population in China reached 269 million, ranked the second in the world in 2015. Gasoline vehicle is identified to be the main source for urban PM2.5 in China, accounting for 15%-31%. In this study the impact of fuel components on PM2.5 and volatile organic compounds (VOCs) emissions from a gasoline port fuel injection (PFI) engine and a gasoline direct injection (GDI) engine are discussed. Results show that, higher proportion of aromatics, alkenes or sulfur in gasoline fuel will lead to higher PM emissions. The PM from the PFI engine mainly consists of OC and a small amount of EC and inorganic ions, while the PM discharge from the GDI engine mainly consists of EC, OM and a small amount of inorganic ions. Since the GDI engines can reduce fuel consumption and CO2 emissions, and it would become more and more popular in the near future. The characteristics of POM component, emission factors and source profile were investigated from GDI engine, particularly focused on the effect of engine speed, load and the catalyst, which will be very much helpful for source identification as source indicators. Chamber experiments were conducted to quantify the potential of secondary aerosol formation from exhaust of a PFI gasoline engine and China V gasoline fuel. During 4-5 h simulation, equivalent to10 days of atmospheric photo-oxidation in Beijing, the extreme SOA production was 426 ± 85 mg/kg fuel, with high precursors and OH exposure. 14% of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatility organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reduction of emissions of aerosol precursor gases from vehicles is essential to mediate pollution in China.

The effects of evaporating essential oils on indoor air quality

NASA Astrophysics Data System (ADS)

Su, Huey-Jen; Chao, Chung-Jen; Chang, Ho-Yuan; Wu, Pei-Chih

Essential oils, predominantly comprised of a group of aromatic chemicals, have attracted increasing attention as they are introduced into indoor environments through various forms of consumer products via different venues. Our study aimed to characterize the profiles and concentrations of emitted volatile organic compounds (VOCs) when evaporating essential oils indoors. Three popular essential oils in the market, lavender, eucalyptus, and tea tree, based on a nation-wide questionnaire survey, were tested. Specific aromatic compounds of interest were sampled during evaporating the essential oils, and analyzed by GC-MS. Indoor carbon monoxide (CO), carbon dioxide (CO 2), total volatile organic compounds (TVOCs), and particulate matters (PM 10) were measured by real-time, continuous monitors, and duplicate samples for airborne fungi and bacteria were collected in different periods of the evaporation. Indoor CO (average concentration 1.48 vs. 0.47 ppm at test vs. background), CO 2 (543.21 vs. 435.47 ppm), and TVOCs (0.74 vs. 0.48 ppm) levels have increased significantly after evaporating essential oils, but not the PM 10 (2.45 vs. 2.42 ppm). The anti-microbial activity on airborne microbes, an effect claimed by the use of many essential oils, could only be found at the first 30-60 min after the evaporation began as the highest levels of volatile components in these essential oils appeared to emit into the air, especially in the case of tea tree oil. High emissions of linalool (0.092-0.787 mg m -3), eucalyptol (0.007-0.856 mg m -3), D-limonene (0.004-0.153 mg m -3), ρ-cymene (0.019-0.141 mg m -3), and terpinene-4-ol-1 (0.029-0.978 mg m -3), all from the family of terpenes, were observed, and warranted for further examination for their health implications, especially for their potential contribution to the increasing indoor levels of secondary pollutants such as formaldehyde and secondary organic aerosols (SOAs) in the presence of ozone.

Non-methane organic gas emissions from biomass burning: identification, quantification, and emission factors from PTR-ToF during the FIREX 2016 laboratory experiment

NASA Astrophysics Data System (ADS)

Koss, Abigail R.; Sekimoto, Kanako; Gilman, Jessica B.; Selimovic, Vanessa; Coggon, Matthew M.; Zarzana, Kyle J.; Yuan, Bin; Lerner, Brian M.; Brown, Steven S.; Jimenez, Jose L.; Krechmer, Jordan; Roberts, James M.; Warneke, Carsten; Yokelson, Robert J.; de Gouw, Joost

2018-03-01

Volatile and intermediate-volatility non-methane organic gases (NMOGs) released from biomass burning were measured during laboratory-simulated wildfires by proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF). We identified NMOG contributors to more than 150 PTR ion masses using gas chromatography (GC) pre-separation with electron ionization, H3O+ chemical ionization, and NO+ chemical ionization, an extensive literature review, and time series correlation, providing higher certainty for ion identifications than has been previously available. Our interpretation of the PTR-ToF mass spectrum accounts for nearly 90 % of NMOG mass detected by PTR-ToF across all fuel types. The relative contributions of different NMOGs to individual exact ion masses are mostly similar across many fires and fuel types. The PTR-ToF measurements are compared to corresponding measurements from open-path Fourier transform infrared spectroscopy (OP-FTIR), broadband cavity-enhanced spectroscopy (ACES), and iodide ion chemical ionization mass spectrometry (I- CIMS) where possible. The majority of comparisons have slopes near 1 and values of the linear correlation coefficient, R2, of > 0.8, including compounds that are not frequently reported by PTR-MS such as ammonia, hydrogen cyanide (HCN), nitrous acid (HONO), and propene. The exceptions include methylglyoxal and compounds that are known to be difficult to measure with one or more of the deployed instruments. The fire-integrated emission ratios to CO and emission factors of NMOGs from 18 fuel types are provided. Finally, we provide an overview of the chemical characteristics of detected species. Non-aromatic oxygenated compounds are the most abundant. Furans and aromatics, while less abundant, comprise a large portion of the OH reactivity. The OH reactivity, its major contributors, and the volatility distribution of emissions can change considerably over the course of a fire.

Characterisation of nano- and micron-sized airborne and collected subway particles, a multi-analytical approach.

PubMed

Midander, Klara; Elihn, Karine; Wallén, Anna; Belova, Lyuba; Karlsson, Anna-Karin Borg; Wallinder, Inger Odnevall

2012-06-15

Continuous daily measurements of airborne particles were conducted during specific periods at an underground platform within the subway system of the city center of Stockholm, Sweden. Main emphasis was placed on number concentration, particle size distribution, soot content (analyzed as elemental and black carbon) and surface area concentration. Conventional measurements of mass concentrations were conducted in parallel as well as analysis of particle morphology, bulk- and surface composition. In addition, the presence of volatile and semi volatile organic compounds within freshly collected particle fractions of PM(10) and PM(2.5) were investigated and grouped according to functional groups. Similar periodic measurements were conducted at street level for comparison. The investigation clearly demonstrates a large dominance in number concentration of airborne nano-sized particles compared to coarse particles in the subway. Out of a mean particle number concentration of 12000 particles/cm(3) (7500 to 20000 particles/cm(3)), only 190 particles/cm(3) were larger than 250 nm. Soot particles from diesel exhaust, and metal-containing particles, primarily iron, were observed in the subway aerosol. Unique measurements on freshly collected subway particle size fractions of PM(10) and PM(2.5) identified several volatile and semi-volatile organic compounds, the presence of carcinogenic aromatic compounds and traces of flame retardants. This interdisciplinary and multi-analytical investigation aims to provide an improved understanding of reported adverse health effects induced by subway aerosols. Copyright © 2012 Elsevier B.V. All rights reserved.

Atmospheric Chemistry of Micrometeoritic Organic Compounds

NASA Technical Reports Server (NTRS)

Kress, M. E.; Belle, C. L.; Pevyhouse, A. R.; Iraci, L. T.

2011-01-01

Micrometeorites approx.100 m in diameter deliver most of the Earth s annual accumulation of extraterrestrial material. These small particles are so strongly heated upon atmospheric entry that most of their volatile content is vaporized. Here we present preliminary results from two sets of experiments to investigate the fate of the organic fraction of micrometeorites. In the first set of experiments, 300 m particles of a CM carbonaceous chondrite were subject to flash pyrolysis, simulating atmospheric entry. In addition to CO and CO2, many organic compounds were released, including functionalized benzenes, hydrocarbons, and small polycyclic aromatic hydrocarbons. In the second set of experiments, we subjected two of these compounds to conditions that simulate the heterogeneous chemistry of Earth s upper atmosphere. We find evidence that meteor-derived compounds can follow reaction pathways leading to the formation of more complex organic compounds.

Does oolong tea (Camellia sinensis) made from a combination of leaf and stem smell more aromatic than leaf-only tea? Contribution of the stem to oolong tea aroma.

PubMed

Zeng, Lanting; Zhou, Ying; Fu, Xiumin; Mei, Xin; Cheng, Sihua; Gui, Jiadong; Dong, Fang; Tang, Jinchi; Ma, Shengzhou; Yang, Ziyin

2017-12-15

The raw materials used to make oolong tea (Camellia sinensis) are a combination of leaf and stem. Oolong tea made from leaf and stem is thought to have a more aromatic smell than leaf-only tea. However, there is no available evidence to support the viewpoint. In this study, sensory evaluation and detailed characterization of emitted and internal volatiles (not readily emitted, but stored in samples) of dry oolong teas and infusions indicated that the presence of stem did not significantly improve the total aroma characteristics. During the enzyme-active processes, volatile monoterpenes and theanine were accumulated more abundantly in stem than in leaf, while jasmine lactone, indole, and trans-nerolidol were lower in stem than in leaf. Tissue-specific aroma-related gene expression and availability of precursors of aroma compounds resulted in different aroma distributions in leaf and stem. This study presents the first determination of the contribution of stem to oolong tea aroma. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improving the conversion of biomass in catalytic fast pyrolysis via white-rot fungal pretreatment.

PubMed

Yu, Yanqing; Zeng, Yelin; Zuo, Jiane; Ma, Fuying; Yang, Xuewei; Zhang, Xiaoyu; Wang, Yujue

2013-04-01

This study investigated the effect of white-rot fungal pretreatment on corn stover conversion in catalytic fast pyrolysis (CFP). Corn stover pretreated by white-rot fungus Irpex lacteus CD2 was fast pyrolyzed alone (non-CFP) and with ZSM-5 zeolite (CFP) in a semi-batch pyroprobe reactor. The fungal pretreatment considerably increased the volatile product yields (predominantly oxygenated compounds) in non-CFP, indicating that fungal pretreatment enhances the corn stover conversion in fast pyrolysis. In the presence of ZSM-5 zeolite, these oxygenated volatiles were further catalytically converted to aromatic hydrocarbons, whose yield increased from 10.03 wt.% for the untreated corn stover to 11.49 wt.% for the pretreated sample. In contrast, the coke yield decreased from 14.29 to 11.93 wt.% in CFP following the fungal pretreatment. These results indicate that fungal pretreatment can enhance the production of valuable aromatics and decrease the amount of undesired coke, and thus has a beneficial effect on biomass conversion in CFP. Copyright © 2013 Elsevier Ltd. All rights reserved.

Superfund Record of Decision (EPA Region 6): Lincoln Creosote Site, Bossier City, LA, November 26, 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-10-01

The Lincoln Creosote Site (Site) is located in Bossier City, Louisiana, and consists of a 20-acre industrial area that includes the former location of a wood treatment plant. Wood products such as railroad ties and utility poles were pressure treated at the plant, using creosote, chromated copper-arsenate (CCA) and pentachlorophenol (PCP) as wood preservatives. The compounds used for wood treatment contained metals, a number of semi-volatile organic base-neutral extractable compounds such as polynuclear aromatic hydrocarbon (PAHs). EPA`s selected removal action called for excavation of residential soils containing concentrations of wood treatment product residuals.

Lithographic dry development using optical absorption

DOEpatents

Olynick, Deirdre; Schuck, P. James; Schmidt, Martin

2013-08-20

A novel approach to dry development of exposed photo resist is described in which a photo resist layer is exposed to a visible light source in order to remove the resist in the areas of exposure. The class of compounds used as the resist material, under the influence of the light source, undergoes a chemical/structural change such that the modified material becomes volatile and is thus removed from the resist surface. The exposure process is carried out for a time sufficient to ablate the exposed resist layer down to the layer below. A group of compounds found to be useful in this process includes aromatic calixarenes.

Screening of oil sources by using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry and multivariate statistical analysis.

PubMed

Zhang, Wanfeng; Zhu, Shukui; He, Sheng; Wang, Yanxin

2015-02-06

Using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOFMS), volatile and semi-volatile organic compounds in crude oil samples from different reservoirs or regions were analyzed for the development of a molecular fingerprint database. Based on the GC×GC/TOFMS fingerprints of crude oils, principal component analysis (PCA) and cluster analysis were used to distinguish the oil sources and find biomarkers. As a supervised technique, the geological characteristics of crude oils, including thermal maturity, sedimentary environment etc., are assigned to the principal components. The results show that tri-aromatic steroid (TAS) series are the suitable marker compounds in crude oils for the oil screening, and the relative abundances of individual TAS compounds have excellent correlation with oil sources. In order to correct the effects of some other external factors except oil sources, the variables were defined as the content ratio of some target compounds and 13 parameters were proposed for the screening of oil sources. With the developed model, the crude oils were easily discriminated, and the result is in good agreement with the practical geological setting. Copyright © 2014 Elsevier B.V. All rights reserved.

Grape cluster microclimate influences the aroma composition of Sauvignon blanc wine.

PubMed

Martin, Damian; Grose, Claire; Fedrizzi, Bruno; Stuart, Lily; Albright, Abby; McLachlan, Andrew

2016-11-01

New Zealand Sauvignon blanc (SB) wines are characterised by a distinctive combination of tropical-fruity and green-herbaceous aromatic compounds. The influence of sunlight exposure of grape clusters on juice and wine composition was investigated, with the aim of manipulating aromatic compounds in SB wine. In the absence of basal leaf removal SB clusters naturally exposed to sunlight were riper than shaded clusters, evidenced by higher total soluble solids (TSS) and proline, and lower malic acid, 3-isobutyl-2-methoxypyrazine (IBMP) and arginine. Volatile thiols in wines did not differ between shaded and exposed clusters. At equivalent TSS, cluster exposure had little or no effect on malic acid concentration. Conversely, wine from shaded clusters had almost double the IBMP concentration of wine from exposed clusters at equivalent TSS. The effects on SB juice and wine composition of natural variations in cluster microclimate are not comparable with the effects of cluster exposure created through leaf removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of a Zeolite Filter for Removing Polycyclic Aromatic Hydrocarbons (PAHs) from Smoke and Smoked Ingredients while Retaining the Smoky Flavor.

PubMed

Parker, Jane K; Lignou, Stella; Shankland, Kenneth; Kurwie, Phillipa; Griffiths, Huw D; Baines, David A

2018-03-14

The popularity of smoked foodstuffs such as sauces, marinades, and rubs is on the rise. However, during the traditional smoking process, in addition to the desirable smoky aroma compounds, harmful polycyclic aromatic hydrocarbons (PAHs) are also generated. In this work, a selective filter was developed that reduces PAH concentrations in a smoke by up to 90% while maintaining a desirable smoky flavor. Preliminary studies using a cocktail of 12 PAHs stirred with a zeolite showed the potential for this zeolite to selectively remove PAHs from a simple solution. However, pretreatment of the smoke prior to application removed the PAHs more efficiently and is more widely applicable to a range of food ingredients. Although volatile analysis showed that there was a concomitant reduction in the concentration of the smoky compounds such as 2-methoxyphenol (guaiacol), 2-methylphenol ( o-cresol), and the isoeugenols, sensory profiling showed that the difference in perception of flavor was minimal.

Derived Emission Rates and Photochemical Production Rates of Volatile Organic Compounds (VOCs) Associated with Oil and Natural Gas Operations in the Uintah Basin, UT During a Wintertime Ozone Formation Event

NASA Astrophysics Data System (ADS)

Koss, A.; De Gouw, J. A.; Warneke, C.; Gilman, J.; Lerner, B. M.; Graus, M.; Yuan, B.; Edwards, P. M.; Brown, S. S.; Wild, R. J.; Roberts, J. M.; Bates, T. S.; Quinn, P.

2014-12-01

The Uintah Basin, an oil and natural gas extraction field in Utah, experienced extremely high levels of volatile organic compounds (VOCs) and ozone during the winter of 2013 - up to 100 ppmv carbon and 150 ppbv O3. Here we interpret VOCs measured during an ozone formation event from 31 Jan 2013 to 8 Feb 2013. Ratios of VOCs show strong diurnal cycles and week-long trends. A simple analysis was applied to ratios of aromatic VOCs measured by proton transfer reaction mass spectrometer (PTR-MS) to explain these trends and to estimate emission rates of aromatic VOCs from oil and natural gas extraction, VOC emission ratios relative to benzene, and ambient [OH]. The analysis incorporates the following assumptions: (1) the source composition of emitted VOCs and their emission rates were temporally and spatially constant, and (2) the removal of VOCs was governed by reaction with OH, diurnal profile of which is constrained by measured photolysis rates. The main findings are (1) the emission rate of methane, extrapolated from the emission rate of benzene, is on the same order as an independent estimate from aircraft measurements of methane in 2012, (2) the derived aromatic emission ratios are consistent with source contributions from both oil and gas producing wells, and (3) calculated daily OH concentrations are low, peaking at 1x106 molecules cm-3. The analysis was extended to investigate secondary production of oxygenated VOCs measured by PTR-MS. The analysis is able to explain daytime production, but it does not adequately explain nighttime behavior, which may be affected by complex deposition to snow and ice surfaces. The relative carbon mass of primary and secondary compounds was calculated and compared to observations. At the end of the ozone formation event (day 6), our analysis predicts that secondary (oxidized) VOCs should comprise about 40% of total carbon mass. However, only 12% of these compounds are accounted for by measured oxygenated VOCs and organic aerosol. Additionally, formation rates of measured oxygenated VOCs did not sum to the total primary compound oxidation rate. The disparity is likely due to both incomplete measurements of oxygenated products and VOC loss to deposition.

Relations between Land Use and Organochlorine Pesticides, PCBs, and Semi-Volatile Organic Compounds in Streambed Sediment and Fish on the Island of Oahu, Hawaii

USGS Publications Warehouse

Brasher, A.M.D.; Wolff, R.H.

2004-01-01

Bed-sediment and/or fish samples were collected from 27 sites around the island of Oahu (representing urban, agricultural, mixed, and forested land use) to determine the occurrence and distribution of hydrophobic organic compounds including organochlorine pesticides, polychlorinated biphenyls (PCBs), and semi-volatile organic compounds (SVOCs). Of the 28 organochlorine compounds analyzed in the fish, 14 were detected during this study. Nineteen of the 31 organochlorine compounds and 40 of the 65 SVOCs were detected in the sediment. Urban sites had the highest number of detections and tended to have the highest concentrations of pesticides. Chlordane compounds were the most frequently detected constituents at urban sites, followed by dieldrin, polycyclic aromatic hydrocarbons (PAHs), and DDT compounds. PAHs were the most frequently detected constituents in watersheds with mixed (urban and agricultural) land use. The only pesticides detected at agricultural sites were DDT and its degradation products, DDD and DDE. No pesticides or PCBs were detected at the forested sites, but a few ubiquitous SVOCs were found in sediments at some forested sites. In general, concentrations of the most frequently detected pesticides were higher in fish than in sediment. Following a trend that has been observed elsewhere in the nation, concentrations of most organochlorine pesticides and PCBs are decreasing in Hawaii.

Ventilation Control of Volatile Organic Compounds in New U.S. Homes: Results of a Controlled Field Study in Nine Residential Units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willem, Henry; Hult, Erin L.; Hotchi, Toshifumi

2013-01-01

In order to optimize strategies to remove airborne contaminants in residences, it is necessary to determine how contaminant concentrations respond to changes in the air exchange rate. The impact of air exchange rate on the indoor concentrations of 39 target volatile organic compounds (VOCs) was assessed by measuring air exchange rates and VOC concentrations at three ventilation settings in nine residences. Active sampling methods were used for VOC concentration measurements, and passive perfluorocarbon tracer gas emitters with active sampling were used to determine the overall air exchange rate corresponding to the VOC measurements at each ventilation setting. The concentration levelsmore » and emission rates of the target VOCs varied by as much as two orders of magnitude across sites. Aldehyde and terpene compounds were typically the chemical classes with highest concentrations, followed by alkanes, aromatics, and siloxanes. For each home, VOC concentrations tended to decrease as the air exchange rate was increased, however, measurement uncertainty was significant. The indoor concentration was inversely proportional to air exchange rate for most compounds. For a subset of compounds including formaldehyde, however, the indoor concentration exhibited a non-linear dependence on the timescale for air exchange« less

Ventilation Control of Volatile Organic Compounds in New U.S. Homes: Results of a Controlled Field Study in Nine Residential Units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willem, Henry; Hult, Erin L.; Hotchi, Toshifumi

2013-01-23

In order to optimize strategies to remove airborne contaminants in residences, it is necessary to determine how contaminant concentrations respond to changes in the air exchange rate. The impact of air exchange rate on the indoor concentrations of 39 target volatile organic compounds (VOCs) was assessed by measuring air exchange rates and VOC concentrations at three ventilation settings in nine residences. Active sampling methods were used for VOC concentration measurements, and passive perfluorocarbon tracer gas emitters with active sampling were used to determine the overall air exchange rate corresponding to the VOC measurements at each ventilation setting. The concentration levelsmore » and emission rates of the target VOCs varied by as much as two orders of magnitude across sites. Aldehyde and terpene compounds were typically the chemical classes with highest concentrations, followed by alkanes, aromatics, and siloxanes. For each home, VOC concentrations tended to decrease as the air exchange rate was increased, however, measurement uncertainty was significant. The indoor concentration was inversely proportional to air exchange rate for most compounds. For a subset of compounds including formaldehyde, however, the indoor concentration exhibited a non-linear dependence on the timescale for air exchange.« less

Volatile Organic Compounds from Logwood Combustion: Emissions and Transformation under Dark and Photochemical Aging Conditions in a Smog Chamber.

PubMed

Hartikainen, Anni; Yli-Pirilä, Pasi; Tiitta, Petri; Leskinen, Ari; Kortelainen, Miika; Orasche, Jürgen; Schnelle-Kreis, Jürgen; Lehtinen, Kari E J; Zimmermann, Ralf; Jokiniemi, Jorma; Sippula, Olli

2018-04-17

Residential wood combustion (RWC) emits high amounts of volatile organic compounds (VOCs) into ambient air, leading to formation of secondary organic aerosol (SOA), and various health and climate effects. In this study, the emission factors of VOCs from a logwood-fired modern masonry heater were measured using a Proton-Transfer-Reactor Time-of-Flight Mass Spectrometer. Next, the VOCs were aged in a 29 m 3 Teflon chamber equipped with UV black lights, where dark and photochemical atmospheric conditions were simulated. The main constituents of the VOC emissions were carbonyls and aromatic compounds, which accounted for 50%-52% and 30%-46% of the detected VOC emission, respectively. Emissions were highly susceptible to different combustion conditions, which caused a 2.4-fold variation in emission factors. The overall VOC concentrations declined considerably during both dark and photochemical aging, with simultaneous increase in particulate organic aerosol mass. Especially furanoic and phenolic compounds decreased, and they are suggested to be the major precursors of RWC-originated SOA in all aging conditions. On the other hand, dark aging produced relatively high amounts of nitrogen-containing organic compounds in both gas and particulate phase, while photochemical aging increased especially the concentrations of certain gaseous carbonyls, particularly acid anhydrides.

Secondary organic aerosol formation and composition from the photo-oxidation of methyl chavicol (estragole)

NASA Astrophysics Data System (ADS)

Pereira, K. L.; Hamilton, J. F.; Rickard, A. R.; Bloss, W. J.; Alam, M. S.; Camredon, M.; Muñoz, A.; Vásquez, M.; Borrás, E.; Ródenas, M.

2013-12-01

The increasing demand for palm oil for uses in biofuel and food products is leading to rapid expansion of oil palm agriculture. Methyl chavicol (also known as estragole and 1-allyl-4-methoxybenzene) is an oxygenated biogenic volatile organic compound that was recently identified as the main floral emission from an oil palm plantation in Malaysian Borneo. The emissions of methyl chavicol observed may impact regional atmospheric chemistry, but little is known of its ability to form secondary organic aerosol (SOA). The photo-oxidation of methyl chavicol was investigated at the European Photoreactor chamber as a part of the atmospheric chemistry of methyl chavicol (ATMECH) project. Aerosol samples were collected using a particle into liquid sampler (PILS) and analysed offline using an extensive range of instruments including; high performance liquid chromatography mass spectrometry (HPLC-ITMS), high performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The SOA yield was determined as 18-29% depending on initial precursor (VOC : NOx) mixing ratios. In total, 59 SOA compounds were observed and the structures of 10 compounds have been identified using high resolution tandem mass spectrometry. The addition of hydroxyl and/or nitro functional groups to the aromatic ring appears to be an important mechanistic pathway for aerosol formation. This results in the formation of compounds with both low volatility and high O : C ratios, where functionalisation rather than fragmentation is mainly observed as a~result of the stability of the ring. The SOA species observed can be characterized as semi-volatile to low volatile oxygenated organic aerosol (SVOOA and LVOOA) components and therefore may be important in aerosol formation and growth.

[High-performance liquid-liquid chromatography in beverage analysis].

PubMed

Bricout, J; Koziet, Y; de Carpentrie, B

1978-01-01

Liquid liquid chromatography was performed with columns packed with stationary phases chemically bonded to silica microparticules. These columns show a high efficiency and are used very easily. Flavouring compounds like aromatic aldehydes which have a low volatility were analyzed in brandy using a polar phase alkylnitrile. Sapid substances like amarogentin in Gentiana lutea or glyryrrhizin in Glycyrrhiza glabra were determined by reversed phase chromatography. Finally ionizable substances like synthetic dyes can be analyzed by paired ion chromatography witha non polar stationary phase.

Simulation of SOA formation and composition from oxidation of toluene and m-xylene in chamber experiments

NASA Astrophysics Data System (ADS)

Xu, J.; Liu, Y.; Nakao, S.; Cocker, D.; Griffin, R. J.

2013-12-01

Aromatic hydrocarbons contribute an important fraction of anthropogenic reactive volatile organic compounds (VOCs) in the urban atmosphere. Photo-oxidation of aromatic hydrocarbons leads to secondary organic products that have decreased volatilities or increased solubilities and can form secondary organic aerosol (SOA). Despite the crucial role of aromatic-derived SOA in deteriorating air quality and harming human health, its formation mechanism is not well understood and model simulation of SOA formation still remains difficult. The dependence of aromatic SOA formation on nitrogen oxides (NOx) is not captured fully by most SOA formation models. Most models predict SOA formation under high NOx levels well but underestimate SOA formation under low NOx levels more representative of the ambient atmosphere. Thus, it is crucial to investigate the NOx-dependent chemistry in aromatic photo-oxidation systems and correspondingly update SOA formation models. In this study, NOx-dependent mechanisms of toluene and m-xylene SOA formation are updated using the gas-phase Caltech Atmospheric Chemistry Mechanism (CACM) coupled to a gas/aerosol partitioning model. The updated models were optimized by comparing to eighteen University of California, Riverside United States Environmental Protection Agency (EPA) chamber experiment runs under both high and low NOx conditions. Correction factors for vapor pressures imply uncharacterized aerosol-phase association chemistry. Simulated SOA speciation implies the importance of ring-opening products in governing SOA formation (up to 40%~60% for both aromatics). The newly developed model can predict strong decreases of m-xylene SOA yield with increasing NOx. Speciation distributions under varied NOx levels implies that the well-known competition between RO2 + HO2 and RO2 + NO (RO2 = peroxide bicyclic radical) may not be the only factor influencing SOA formation. The reaction of aromatic peroxy radicals with NO competing with its self-cyclization also affects NOx-dependence of SOA formation. Comparison of SOA formation yield and composition between two aromatics implies aldehyde/ketone chemistry from ring-opening route and chemistry for phenolic route play important roles in governing SOA formation and that ring-opening aldehydes and phenolic nitrates are produced to a greater extent in the toluene system, leading to higher SOA yields for toluene than for m-xylene.

Aroma profile and sensory characteristics of a sulfur dioxide-free mulberry (Morus nigra) wine subjected to non-thermal accelerating aging techniques.

PubMed

Tchabo, William; Ma, Yongkun; Kwaw, Emmanuel; Zhang, Haining; Xiao, Lulu; Tahir, Haroon Elrasheid

2017-10-01

The present study was undertaken to assess accelerating aging effects of high pressure, ultrasound and manosonication on the aromatic profile and sensorial attributes of aged mulberry wines (AMW). A total of 166 volatile compounds were found amongst the AMW. The outcomes of the investigation were presented by means of geometric mean (GM), cluster analysis (CA), principal component analysis (PCA), partial least squares regressions (PLSR) and principal component regression (PCR). GM highlighted 24 organoleptic attributes responsible for the sensorial profile of the AMW. Moreover, CA revealed that the volatile composition of the non-thermal accelerated aged wines differs from that of the conventional aged wines. Besides, PCA discriminated the AMW on the basis of their main sensorial characteristics. Furthermore, PLSR identified 75 aroma compounds which were mainly responsible for the olfactory notes of the AMW. Finally, the overall quality of the AMW was noted to be better predicted by PLSR than PCR. Copyright © 2017 Elsevier Ltd. All rights reserved.

Generation of volatile compounds in litchi wine during winemaking and short-term bottle storage.

PubMed

Wu, Yuwen; Zhu, Baoqing; Tu, Cui; Duan, Changqing; Pan, Qiuhong

2011-05-11

Evolution of volatile components during litchi (Litchi chinensis Sonn.) winemaking was monitored, and aroma profiles of litchi wines bottle aged for 5 months at ambient temperature (25-28 °C) and low temperature (8-10 °C) were compared via headspace solid phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The majority of terpenoids deriving from litchi juice decreased, even disappeared along with alcoholic fermentation, while terpenol oxides, ethers, and acetates came into being and increased. Ethyl octanote, isoamyl acetate, ethyl hexanoate, ethyl butanoate, cis-rose oxide, and trans-rose oxide had the highest odor activity values (OAVs) in young litchi wines. Six aromatic series were obtained by grouping OAVs of odor-active compounds with similar odor descriptions to establish the aroma profile for young litchi wines, and floral and fruity attributes were two major aroma series. Compared to ambient temperature when bottle aging, lower temperature benefited key aroma retention and expectantly extended the shelf life of young litchi wines.

Improvement of wine aromatic quality using mixtures of lysozyme and dimethyl dicarbonate, with low SO2 concentration.

PubMed

Nieto-Rojo, Rodrigo; Luquin, Asuncion; Ancín-Azpilicueta, Carmen

2015-01-01

The use of sulphur dioxide (SO2) in the treatment of foodstuffs presents some problems as it could lead to pseudo-allergies in some people. The aim of this research work was to study the addition of different preservative mixtures and their influence on the concentration of volatile compounds and sensorial quality in wine. To do so, vinifications were carried out using Garnacha must to which lysozyme, dimethyl dicarbonate (DMDC) and mixtures of these with SO2 were added at different doses (25 and 50 mg l(-1)). The results were compared with a control sample to which only SO2 had been added (50 mg l(-1)). In general, mixtures of SO2 with lysozyme and DMDC favoured the formation of volatile compounds in the wines. Wines obtained from the mixtures of lysozyme and DMDC with 25 mg l(-1) of SO2 had better sensorial quality than the wines obtained with 50 mg l(-1) as the only preservative used.

Analysis of Floral Volatile Components and Antioxidant Activity of Different Varieties of Chrysanthemum morifolium.

PubMed

Yang, Lu; Cheng, Ping; Wang, Jin-Hui; Li, Hong

2017-10-23

This study investigated the volatile flavor compounds and antioxidant properties of the essential oil of chrysanthemums that was extracted from the fresh flowers of 10 taxa of Chrysanthemum morifolium from three species; namely Dendranthema morifolium (Ramat.) Yellow, Dendranthema morifolium (Ramat.) Red, Dendranthema morifolium (Ramat.) Pink, Dendranthema morifolium (Ramat.) White, Pericallis hybrid Blue, Pericallis hybrid Pink, Pericallis hybrid Purple, Bellis perennis Pink, Bellis perennis Yellow, and Bellis perennis White. The antioxidant capacity of the essential oil was assayed by spectrophotometric analysis. The volatile flavor compounds from the fresh flowers were collected using dynamic headspace collection, analyzed using auto thermal desorber-gas chromatography/mass spectrometry, and identified with quantification using the external standard method. The antioxidant activities of Chrysanthemum morifolium were evaluated by DPPH and FRAP assays, and the results showed that the antioxidant activity of each sample was not the same. The different varieties of fresh Chrysanthemum morifolium flowers were distinguished and classified by fingerprint similarity evaluation, principle component analysis (PCA), and cluster analysis. The results showed that the floral volatile component profiles were significantly different among the different Chrysanthemum morifolium varieties. A total of 36 volatile flavor compounds were identified with eight functional groups: hydrocarbons, terpenoids, aromatic compounds, alcohols, ketones, ethers, aldehydes, and esters. Moreover, the variability among Chrysanthemum morifolium in basis to the data, and the first three principal components (PC1, PC2, and PC3) accounted for 96.509% of the total variance (55.802%, 30.599%, and 10.108%, respectively). PCA indicated that there were marked differences among Chrysanthemum morifolium varieties. The cluster analysis confirmed the results of the PCA analysis. In conclusion, the results of this study provide a basis for breeding Chrysanthemum cultivars with desirable floral scents, and they further support the view that some plants are promising sources of natural antioxidants.

Detection of semi-volatile organic compounds (SVOCs) in surface water, soil, and groundwater in a chemical industrial park in Eastern China.

PubMed

Liu, Benhua; Li, Yuehua; Ma, Jianfeng; Huang, Linxian; Chen, Liang

2016-01-01

China is suffering from serious water and soil pollution, especially in the North China Plain. This work investigated semi-volatile organic compounds (SVOCs) in surface water, groundwater and soil within a chemical industrial park in Eastern China, for which the volatile organic compound (VOC) results have been previously reported. A total of 20 samples were collected from the field, and analyzed in the laboratory. A 100% detection frequency of SVOCs in samples from this chemical industrial park was observed (same as VOCs). Moreover, the detection frequency of 113 SVOCs in each sample reached 15.93, 12.39 and 20.35% for surface water, groundwater and soil, respectively. The most detected SVOCs in the park included N-containing SVOCs, polycyclic aromatic hydrocarbons, phthalates, organic pesticides and polychlorodiphenyls. The elevated detecting frequencies and concentration levels of SVOCs identified in the groundwater were attributed to the intensive chemical production activities in the park. In addition, the agricultural activities in the area might also have contributed to the SVOCs to the groundwater. The results of VOCs and SVOCs from this and previous studies suggest that the groundwater in this industrial park has been severely contaminated, and the contamination likely spreads beyond the park. Imminent hydrogeological assessments and remedial actions are warranted to eliminate the source and mitigate the potential plume expansion beyond the park boundary.

Potential of secondary aerosol formation from Chinese gasoline engine exhaust.

PubMed

Du, Zhuofei; Hu, Min; Peng, Jianfei; Guo, Song; Zheng, Rong; Zheng, Jing; Shang, Dongjie; Qin, Yanhong; Niu, He; Li, Mengren; Yang, Yudong; Lu, Sihua; Wu, Yusheng; Shao, Min; Shuai, Shijin

2018-04-01

Light-duty gasoline vehicles have drawn public attention in China due to their significant primary emissions of particulate matter and volatile organic compounds (VOCs). However, little information on secondary aerosol formation from exhaust for Chinese vehicles and fuel conditions is available. In this study, chamber experiments were conducted to quantify the potential of secondary aerosol formation from the exhaust of a port fuel injection gasoline engine. The engine and fuel used are common in the Chinese market, and the fuel satisfies the China V gasoline fuel standard. Substantial secondary aerosol formation was observed during a 4-5hr simulation, which was estimated to represent more than 10days of equivalent atmospheric photo-oxidation in Beijing. As a consequence, the extreme case secondary organic aerosol (SOA) production was 426±85mg/kg-fuel, with high levels of precursors and OH exposure. The low hygroscopicity of the aerosols formed inside the chamber suggests that SOA was the dominant chemical composition. Fourteen percent of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatile organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reductions of emissions of aerosol precursor gases from vehicles are essential to mediate pollution in China. Copyright © 2017. Published by Elsevier B.V.

Bio-Based Aromatic Epoxy Monomers for Thermoset Materials.

PubMed

Ng, Feifei; Couture, Guillaume; Philippe, Coralie; Boutevin, Bernard; Caillol, Sylvain

2017-01-18

The synthesis of polymers from renewable resources is a burning issue that is actively investigated. Polyepoxide networks constitute a major class of thermosetting polymers and are extensively used as coatings, electronic materials, adhesives. Owing to their outstanding mechanical and electrical properties, chemical resistance, adhesion, and minimal shrinkage after curing, they are used in structural applications as well. Most of these thermosets are industrially manufactured from bisphenol A (BPA), a substance that was initially synthesized as a chemical estrogen. The awareness on BPA toxicity combined with the limited availability and volatile cost of fossil resources and the non-recyclability of thermosets implies necessary changes in the field of epoxy networks. Thus, substitution of BPA has witnessed an increasing number of studies both from the academic and industrial sides. This review proposes to give an overview of the reported aromatic multifunctional epoxide building blocks synthesized from biomass or from molecules that could be obtained from transformed biomass. After a reminder of the main glycidylation routes and mechanisms and the recent knowledge on BPA toxicity and legal issues, this review will provide a brief description of the main natural sources of aromatic molecules. The different epoxy prepolymers will then be organized from simple, mono-aromatic di-epoxy, to mono-aromatic poly-epoxy, to di-aromatic di-epoxy compounds, and finally to derivatives possessing numerous aromatic rings and epoxy groups.

Dominierende Prozesse bei der thermischen In-situ-Sanierung (TISS) kontaminierter Geringleiter

NASA Astrophysics Data System (ADS)

Hiester, Uwe; Bieber, Laura

2017-09-01

Contaminants such as chlorinated, aromatic or polycyclic aromatic hydrocarbons (CHC, BTEX, PAH) or mineral oil hydrocarbons (TPH) constitute a prevalent threat to water resources. The significant storage capacity of low permeable soils (aquitards) leads to their long-term contamination. In situ thermal remediation (ISTR) proved to work successfully in treating these soils. Thus, the area of ISTR application grew continuously over the past 10 years. The dominating processes during the remediation can vary considerably, depending on hydrogeological and geological boundary conditions and the contamination itself. This article summarizes the application for in-situ thermal remediation (ISTR) in low permeable soils and aquitards for soil and groundwater treatment. Dominating remediation processes during volatile organic compound (VOC) and residual oil phase recovery are presented. The processes are illustrated by project examples.

Personal exposure to volatile organic compounds. I. Direct measurements in breathing-zone air, drinking water, food, and exhaled breath

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallace, L.A.; Pellizzari, E.; Hartwell, T.

A pilot study to test methods of estimating personal exposures to toxic substances and corresponding body burdens was carried out between July and December 1980. Individual exposures to about a dozen volatile organic compounds in air and drinking water were measured for volunteers in New Jersey and North Carolina. Breath samples were also collected from all subjects. About 230 personal air samples, 170 drinking water samples, 66 breath samples, and 4 food samples (16 composites) were analyzed for the target chemicals. Ten compounds were present in air and eight were transmitted mainly through that medium. Chloroform and bromodichloromethane were predominantlymore » transmitted through water and beverages. Food appeared to be a miner route of exposure, except possibly for trichloroethylene in margarine. Seven compounds were present in more than half of the breath samples. Diurnal and seasonal variations were noted in air and water concentrations of some compounds. Some, but not all, of the potentially occupationally exposed individuals had significantly higher workplace exposures to several chemicals. Distributions of air exposures were closer to log normal than normal for most chemicals. Several chemicals were highly correlated with each other in personal air samples, indicating possible common sources of exposures. Compounds detected included benzene, chlorinated aromatic hydrocarbons, chlorinated aliphatic hydrocarbons, halogens and vinyl chloride.« less

Effects of addition of alpha-cyclodextrin on the sensory quality, volatile compounds, and color parameters of fresh pear juice.

PubMed

López-Nicolás, José M; Andreu-Sevilla, Antonio J; Carbonell-Barrachina, Angel A; García-Carmona, Francisco

2009-10-28

Cyclodextrins (CDs) are widely used as browning inhibitors in different fruit juices. However, pear juice quality is affected by many properties, such as odor and aroma, and to date, no paper has reported the effect of the addition of CDs on the flavor profile of a fruit juice. In this study, the aroma profile of pear juice was mainly formed by volatile compounds from four chemical families: esters, aldehydes, alcohols, and hydrocarbons. Even though the addition of alpha-CD had a significant effect on both the concentration of individual volatile compounds and their grouping, only the highest concentration, 90 mM, prevented the oxidation of the volatile precursors present in freshly squeezed juice. Moreover, correlation of these results, concerning the color and aroma of pear juice in the presence of CDs, with the consumer preferences has not been reported. A descriptive sensory analysis of pear juices in both the presence and the absence of CDs was carried out, and odor/aroma attributes (fresh, fruity, pear-like, unnatural, etc.), plus global color, odor, aroma, and quality, were quantified using a trained panel of judges. The addition of alpha-CD at 90 mM resulted in pear juices with the best color but with low aromatic intensity and low sensory quality. On the other hand, the addition of alpha-CD at 15 mM led to a pear juice also with an acceptable color but at the same time with a high intensity of fruity and pear-like odors/aromas, making it the best appreciated juice by the panel.

Effects of maltose and lysine treatment on coffee aroma by flash gas chromatography electronic nose and gas chromatography-mass spectrometry.

PubMed

He, Yuqin; Zhang, Haide; Wen, Nana; Hu, Rongsuo; Wu, Guiping; Zeng, Ying; Li, Xiong; Miao, Xiaodan

2018-01-01

Arabica coffee is a sub-tropical agricultural product in China. Coffee undergoes a series of thermal reactions to form abundant volatile profiles after roasting, so it loses a lot of reducing sugars and amino acids. Adding carbonyl compounds with amino acids before roasting could ensure the nutrition and flavour of coffee. The technology is versatile for the development of coffee roasting process. This investigation evaluates the effects of combining maltose and lysine (Lys) to modify coffee aroma and the possibly related mechanisms. Arabica coffee was pretreated with a series of solvent ratios of maltose and Lys with an identical concentration (0.25 mol L -1 ) before microwave heating. It was found that the combination of maltose and Lys significantly (P ≤ 0.05) influenced quality indices of coffee (pH and browning degree). Ninety-six aromatic volatiles have been isolated and identified. Twelve volatile profiles revealed the relationship between fragrance difference and compound content in coffee. Moreover, coffee aroma was modified by a large number of volatiles with different chemical classes and character. Thus, our results suggest that the combination of reagents changed overall aroma quality through a series of complex thermal reactions, especially the ratio of Lys/maltose over 2:1. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Solvent-free microwave extraction of essential oil from aromatic herbs: from laboratory to pilot and industrial scale.

PubMed

Filly, Aurore; Fernandez, Xavier; Minuti, Matteo; Visinoni, Francesco; Cravotto, Giancarlo; Chemat, Farid

2014-05-01

Solvent-free microwave extraction (SFME) has been proposed as a green method for the extraction of essential oil from aromatic herbs that are extensively used in the food industry. This technique is a combination of microwave heating and dry distillation performed at atmospheric pressure without any added solvent or water. The isolation and concentration of volatile compounds is performed in a single stage. In this work, SFME and a conventional technique, hydro-distillation HD (Clevenger apparatus), are used for the extraction of essential oil from rosemary (Rosmarinus officinalis L.) and are compared. This preliminary laboratory study shows that essential oils extracted by SFME in 30min were quantitatively (yield and kinetics profile) and qualitatively (aromatic profile) similar to those obtained using conventional hydro-distillation in 2h. Experiments performed in a 75L pilot microwave reactor prove the feasibility of SFME up scaling and potential industrial applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Integrated exposure assessment of sewage workers to genotoxicants: an urinary biomarker approach and oxidative stress evaluation

PubMed Central

2011-01-01

Background Sewage workers are exposed to multiple chemicals among which many are suspected genotoxicants. Therefore, they might incur DNA damage and oxidative stress. We aimed to explore integrated urinary biomarkers, assessing the overall urine genotoxicity by in vitro comet and micronucleus assays and measuring urinary 8-oxo-2'-deoxyguanosine. Methods During three consecutive working days, polycyclic aromatic hydrocarbons and volatile organic compounds were sampled in workplace air of 34 sewage and 30 office workers, as indicators of airborne exposure. The last day, subjects collected their 24 hours urine. Genotoxicity of urinary extracts was assessed by comet and micronucleus assays on a HepG2 cell line. Using competitive enzymatic immunoassay we evaluated the 24 hours urinary 8-oxo-2'-deoxyguanosine excretion. Benzo(a)pyrene toxicity equivalent factors and inhalation unit risk for Benzo(a)pyrene and benzene were used to give an estimate of cancer risk levels. Results Workplace air concentrations of polycyclic aromatic hydrocarbons (e.g. 23.7 [range 2.4-104.6] ng.m-3 for fluoranthene) and volatile organic compounds (e.g. 19.1 ± 2.9 [standard error] μ.m-3 for benzene) were elevated in sewage compared to office workplaces (P < 0.01) and corresponded to an increased lifetime cancer risk. The urinary extracts of sewage workers showed higher genotoxicity (P < 0.001) than office workers. Conclusions The integrated and non-specific urinary biomarkers of exposure showed that sewage workers experience exposure to mixtures of genotoxicants in the workplace. PMID:21435260

Integrated exposure assessment of sewage workers to genotoxicants: an urinary biomarker approach and oxidative stress evaluation.

PubMed

Al Zabadi, Hamzeh; Ferrari, Luc; Sari-Minodier, Irène; Kerautret, Marie-Aude; Tiberguent, Aziz; Paris, Christophe; Zmirou-Navier, Denis

2011-03-24

Sewage workers are exposed to multiple chemicals among which many are suspected genotoxicants. Therefore, they might incur DNA damage and oxidative stress. We aimed to explore integrated urinary biomarkers, assessing the overall urine genotoxicity by in vitro comet and micronucleus assays and measuring urinary 8-oxo-2'-deoxyguanosine. During three consecutive working days, polycyclic aromatic hydrocarbons and volatile organic compounds were sampled in workplace air of 34 sewage and 30 office workers, as indicators of airborne exposure. The last day, subjects collected their 24 hours urine. Genotoxicity of urinary extracts was assessed by comet and micronucleus assays on a HepG2 cell line. Using competitive enzymatic immunoassay we evaluated the 24 hours urinary 8-oxo-2'-deoxyguanosine excretion. Benzo(a)pyrene toxicity equivalent factors and inhalation unit risk for Benzo(a)pyrene and benzene were used to give an estimate of cancer risk levels. Workplace air concentrations of polycyclic aromatic hydrocarbons (e.g. 23.7 [range 2.4-104.6] ng.m-3 for fluoranthene) and volatile organic compounds (e.g. 19.1 ± 2.9 [standard error] μ.m-3 for benzene) were elevated in sewage compared to office workplaces (P < 0.01) and corresponded to an increased lifetime cancer risk. The urinary extracts of sewage workers showed higher genotoxicity (P < 0.001) than office workers. The integrated and non-specific urinary biomarkers of exposure showed that sewage workers experience exposure to mixtures of genotoxicants in the workplace.

A dynamic dilution system-based evaluation of the procedure adopted for determining ozone precursor volatile compounds.

PubMed

Palluau, Fabienne; Mirabel, Philippe; Millet, Maurice

2005-02-01

A dynamic dilution system was created to evaluate the performance and the reliability of ozone precursor volatile organic compound (VOC) sampling ("TO-Can" canisters) and analysis (thermal desorption/gas chromatography/flame ionisation detection) techniques used by the "Laboratoire Interregional de Chimie du Grand Est (LIC)". Different atmospheres of VOCs were generated at concentrations between 0.8 and 25 ppb, with temperatures of 0, 10, 20 and 30 degrees C, and with relative humidities of 0, 30, 50, 70 and 90%. These conditions are generally representative of those commonly observed in ambient air in the eastern France. This dynamic dilution allows the simulation of a wide range of scenarios (concentrations, temperatures and relative humidities). After assessing the capacity and performance of the system, it was applied in order to evaluate the recoveries and stabilities of VOCs from canisters used for the collection and analysis of two mixtures of VOCs. The first mixture contained six alkanes (ethane, propane, butane, pentane, hexane and heptane), and the second contained five alkenes (ethene, propene, butene, 1-pentene and 1-hexene), five aromatics (benzene, toluene, ethylbenzene, m-xylene and o-xylene), acetylene, and 1,3-butadiene. No significant losses of alkanes from the canisters were observed after 21 days of storage, and good recoveries of alkanes from the canisters (>80%) were obtained regardless of the concentration, the temperature and the relative humidity. However, losses of certain aromatics were noted at low relative humidity.

Influence of extraction methodologies on the analysis of five major volatile aromatic compounds of citronella grass (Cymbopogon nardus) and lemongrass (Cymbopogon citratus) grown in Thailand.

PubMed

Chanthai, Saksit; Prachakoll, Sujitra; Ruangviriyachai, Chalerm; Luthria, Devanand L

2012-01-01

This paper deals with the systematic comparison of extraction of major volatile aromatic compounds (VACs) of citronella grass and lemongrass by classical microhydrodistillation (MHD), as well as modern accelerated solvent extraction (ASE). Sixteen VACs were identified by GC/MS. GC-flame ionization detection was used for the quantification of five VACs (citronellal, citronellol, geraniol, citral, and eugenol) to compare the extraction efficiency of the two different methods. Linear range, LOD, and LOQ were calculated for the five VACs. Intraday and interday precisions for the analysis of VACs were determined for each sample. The extraction recovery, as calculated by a spiking experiment with known standards of VACs, by ASE and MHD ranged from 64.9 to 91.2% and 74.3 to 95.2%, respectively. The extraction efficiency of the VACs was compared for three solvents of varying polarities (hexane, dichloromethane, and methanol), seven different temperatures (ranging from 40 to 160 degrees C, with a gradual increment of 20 degrees C), five time periods (from 1 to 10 min), and three cycles (1, 2, and 3 repeated extractions). Optimum extraction yields of VACs were obtained when extractions were carried out for 7 min with dichloromethane and two extraction cycles at 120 degrees C. The results showed that the ASE technique is more efficient than MHD, as it results in improved yields and significant reduction in extraction time with automated extraction capabilities.

Partially oxidised organic components in urban aerosol using GCXGC-TOF/MS

NASA Astrophysics Data System (ADS)

Hamilton, J. F.; Webb, P. J.; Lewis, A. C.; Hopkins, J. R.; Smith, S.; Davy, P.

2004-08-01

Partially oxidised organic compounds associated with PM2.5 aerosol collected in London, England, have been analysed using direct thermal desorption coupled to comprehensive gas chromatography-time of flight mass spectrometry (GCXGC-TOF/MS). Over 10000 individual organic components were isolated from around 10µg of aerosol material in a single procedure and with no sample pre-treatment. Chemical functionalities observed using this analytical technique ranged from alkanes to poly-oxygenated species. The chemical band structures commonly used in GCXGC for group type identifications overlap for this sample type, and have required mass spectrometry as an additional level of instrument dimensionality. An investigation of oxygenated volatile organic compounds (o-VOC) contained within urban aerosol has been performed and in a typical sample around 130 o-VOCs were identified based on retention behaviour and spectral match. In excess of 100 other oxygenated species were also observed but lack of mass spectral library or pure components prevents positive identification. Many of the carbonyl species observed could be mechanistically linked to gas phase aromatic hydrocarbon oxidation and there is good agreement in terms of speciation between the urban samples analysed here and those degradation products observed in smog chamber experiments of aromatic oxidation. The presence of partially oxidised species such as linear chain aldehydes and ketones and cyclic products such as furanones suggests that species generated early in the oxidative process may undergo gas to particle partitioning despite their relatively high volatility.

Partially oxidised organic components in urban aerosol using GCXGC-TOF/MS

NASA Astrophysics Data System (ADS)

Hamilton, J.; Webb, P.; Lewis, A.; Hopkins, J.; Smith, S.; Davy, P.

2004-03-01

Partially oxidised organic compounds associated with PM2.5 aerosol collected in London, England, have been analysed using direct thermal desorption coupled to comprehensive gas chromatography-time of flight mass spectrometry (GCXGC-OF/MS). Over 10 000 individual organic components were isolated from around 10 μg of aerosol material in a single procedure and with no sample pre-treatment. Chemical functionalities observed using this analytical technique ranged from alkanes to poly-oxygenated species. The chemical band structures commonly used in GCXGC for group type identifications overlap for this sample type, and have required mass spectrometry as an additional level of instrument dimensionality. An investigation of oxygenated volatile organic compounds (o-VOC) contained within urban aerosol has been performed and in a typical sample around 130 o-VOCs were identified based on retention behaviour and spectral match. In excess of 100 other oxygenated species were also observed but lack of mass spectral library or pure components prevents positive identification. Many of the carbonyl species observed could be mechanistically linked to gas phase aromatic hydrocarbon oxidation and there is good agreement in terms of speciation between the urban samples analysed here and those degradation products observed in smog chamber experiments of aromatic oxidation. The presence of partially oxidised species such as linear chain aldehydes and ketones and cyclic products such as furanones suggests that species generated relatively early in the oxidative process may undergo gas to particle partitioning despite their relatively high volatility.

Generation of standard gas mixtures of halogenated, aliphatic, and aromatic compounds and prediction of the individual output rates based on molecular formula and boiling point.

PubMed

Thorenz, Ute R; Kundel, Michael; Müller, Lars; Hoffmann, Thorsten

2012-11-01

In this work, we describe a simple diffusion capillary device for the generation of various organic test gases. Using a set of basic equations the output rate of the test gas devices can easily be predicted only based on the molecular formula and the boiling point of the compounds of interest. Since these parameters are easily accessible for a large number of potential analytes, even for those compounds which are typically not listed in physico-chemical handbooks or internet databases, the adjustment of the test gas source to the concentration range required for the individual analytical application is straightforward. The agreement of the predicted and measured values is shown to be valid for different groups of chemicals, such as halocarbons, alkanes, alkenes, and aromatic compounds and for different dimensions of the diffusion capillaries. The limits of the predictability of the output rates are explored and observed to result in an underprediction of the output rates when very thin capillaries are used. It is demonstrated that pressure variations are responsible for the observed deviation of the output rates. To overcome the influence of pressure variations and at the same time to establish a suitable test gas source for highly volatile compounds, also the usability of permeation sources is explored, for example for the generation of molecular bromine test gases.

Volatile profile of aromatic and non-aromatic rice cultivars using SPME/GC-MS

USDA-ARS?s Scientific Manuscript database

Rice (Oryza sativa L.) is enjoyed by many people as a staple food because of its flavor and texture. Some cultivars, like scented rice, are preferred over others due to their distinctive aroma and flavor. The volatile profile of rice has been explored by many investigators, some of whom have also ...

Volatile profile of aromatic and non-aromatic rice cultivars using SPME/GC-MS

USDA-ARS?s Scientific Manuscript database

Rice (Oryza sativa L.) is enjoyed by many people as a staple food because of its flavor and texture. Some cultivars, like scented rice, are preferred over others due to their distinctive aroma and flavor. The volatile profile of rice has been explored by many investigators, some of whom have deter...

Comparative study of aromatic compounds in fruit wines from raspberry, strawberry, and mulberry in central Shaanxi area

PubMed Central

Feng, Yiming; Liu, Min; Ouyang, Yanan; Zhao, Xianfang; Ju, Yanlun; Fang, Yulin

2015-01-01

Background Although grape wines have firmly dominated the production and consumption markets of fruit wines, raspberry, strawberry, and mulberry have been utilized to make wines because of their joyful aroma and high contents of polyphenolic phytochemicals and essential fatty acids. However, little is known about aromatic compounds of the wines produced from these three fruits. Methods The aromatic composition of fruit wines produced from raspberry, strawberry, mulberry, and red grape was analyzed by GC-MS. Odor activity values (OAVs) and relative odor contributions (ROCs) were used to estimate the sensory contribution of the aromatic compounds to the overall flavor of the wines. Results In strawberry, raspberry, and mulberry wines, 27, 30, and 31 odorants were detected, respectively. Alcohols formed the most abundant group, followed by esters and acids. The grape wine contained a wider variety (16 types) of alcohols, and 4-methyl-2-pentanol and 2,3-butanediol were not present in the three fruit wines. The quantity of esters in raspberry (1.54%) and mulberry wines (2.08%) were higher than those of strawberry wine (0.78%), and mulberry wine contained more types of esters. There were no significant differences of acids between the three fruit wines and the control wine. In addition, 2-heptanone, 2-octanone, 2-nonanone, and 2-undecanone were unique to raspberry wine, and nonanal was present only in mulberry wine. The indistinguishable aroma of the three fruit wines was attributed to the dominance of fruity and floral odor components derived from ethyl esters of fatty acids and their contributions to the global aroma of the three fruit wines. Conclusion The present study demonstrated that there were significant differences in the volatile components of fruit wines made from raspberry, strawberry, and mulberry. The aroma compounds were more abundant in the raspberry and mulberry wines than in the strawberry wine, but the quality of strawberry wine was superior to raspberry and mulberry wines. PMID:26617387

Effect of infusion of spices into the oil vs. combined malaxation of olive paste and spices on quality of naturally flavoured virgin olive oils.

PubMed

Caponio, Francesco; Durante, Viviana; Varva, Gabriella; Silletti, Roccangelo; Previtali, Maria Assunta; Viggiani, Ilaria; Squeo, Giacomo; Summo, Carmine; Pasqualone, Antonella; Gomes, Tommaso; Baiano, Antonietta

2016-07-01

Olive oil flavouring with aromatic plants and spices is a traditional practice in Mediterranean gastronomy. The aim of this work was to compare the influence of two different flavouring techniques (infusion of spices into the oil vs. combined malaxation of olives paste and spices) on chemical and sensory quality of flavoured olive oil. In particular, oxidative and hydrolytic degradation (by routine and non-conventional analyses), phenolic profiles (by HPLC), volatile compounds (by SPME-GC/MS), antioxidant activity, and sensory properties (by a trained panel and by consumers) of the oils were evaluated. The obtained results evidenced that the malaxation method was more effective in extracting the phenolic compounds, with a significantly lower level of hydrolysis of secoiridoids. As a consequence, antioxidant activity was significantly lower in the oils obtained by infusion, which were characterized by a higher extent of the oxidative degradation. The volatile compounds were not significantly influenced by changing the flavouring method, apart for sulfur compounds that were more abundant in the oils obtained by the combined malaxation method. From a sensory point of view, more intense bitter and pungent tastes were perceived when the infusion method was adopted. Copyright © 2016 Elsevier Ltd. All rights reserved.

Volatile organic compound constituents from an integrated iron and steel facility.

PubMed

Tsai, Jiun-Horng; Lin, Kuo-Hsiung; Chen, Chih-Yu; Lai, Nina; Ma, Sen-Yi; Chiang, Hung-Lung

2008-09-15

This study measured the volatile organic compound (VOC) constituents of four processes in an integrated iron and steel industry; cokemaking, sintering, hot forming, and cold forming. Toluene, 1,2,4-trimethylbenzene, isopentane, m,p-xylene, 1-butene, ethylbenzene, and benzene were the predominant VOC species in these processes. However, some of the chlorinated compounds were high (hundreds ppbv), i.e., trichloroethylene in all four processes, carbon tetrachloride in the hot forming process, chlorobenzene in the cold forming process, and bromomethane in the sintering process. In the sintering process, the emission factors of toluene, benzene, xylene, isopentane, 1,2,4-trimethylbenzene, and ethylbenzene were over 9 g/tonne-product. In the vicinity of the manufacturing plant, toluene, isopentane, 1,2,4-trimethylbenzene, xylene and ethylbenzene were high. Toluene, 1,2,4-trimethylbenzene, xylene, 1-butene and isopentane were the major ozone formation species. Aromatic compounds were the predominant VOC groups, constituting 45-70% of the VOC concentration and contributing >70% to the high ozone formation potential in the stack exhaust and workplace air. The sequence of VOC concentration and ozone formation potential was as follows: cold forming>sintering>hot forming>cokemaking. For the workplace air, cokemaking was the highest producer, which was attributed to the fugitive emissions of the coke oven and working process release.

Sensory and analytical evaluations of paints with and without texanol.

PubMed

Gallagher, Michelle; Dalton, Pamela; Sitvarin, Laura; Preti, George

2008-01-01

Perception of odor can figure prominently in complaints about indoor air,yet identification of the responsible compound(s) is often difficult. For example, paint emissions contain a variety of odorous volatile organic compounds (VOCs) which maytrigger reports of irritation and upper respiratory health effects. Texanol ester alcohol (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), a paint coalescing agent, is frequently associated with the "persistent, characteristic odor" of water-based paint. To evaluate the sensory impact of Texanol, naive (unfamiliar with paint constituents) and experienced (familiar with paint constituents) subjects evaluated the odor properties of paints with and without Texanol. VOC emissions from neat paint and paint applied to gypsum wallboard were collected via solid-phase microextraction and analyzed by gas chromatography/ mass spectrometry and gas chromatography/olfactometry. Regardless of subjects' prior experience, aromatic hydrocarbons and oxygenated compounds, introduced from other paint additives and not Texanol, were most commonly associated with paint odor. However, quantitative sensory techniques demonstrated that addition of Texanol to paints led to an overall increase in the perceived intensity of the coating. The combined use of these techniques proved to be an effective methodology for analyzing the structure of paint volatiles and their sensory properties and holds promise for solving many odorous indoor air problems.

Analysis of particle-associated semi-volatile aromatic and aliphatic hydrocarbons in urban particulate matter on a daily basis

NASA Astrophysics Data System (ADS)

Schnelle-Kreis, Jürgen; Sklorz, Martin; Peters, Anette; Cyrys, Josef; Zimmermann, Ralf

PM 2.5 Particle-associated semi-volatile organic compounds (SVOC) were determined in the city of Augsburg, Germany. Daily samples were collected at a central monitoring station from late summer to late autumn 2002. The concentrations of polycyclic aromatic hydrocarbons (PAH), oxidized PAH (O-PAH), n-alkanes, hopanes and long chain linear alkylbenzenes were determined by direct thermal desorption-gas chromatography-time of flight mass spectrometry (DTD-GC-TOFMS). Additionally, PM 2.5 particle mass and number concentrations were measured. The sampling campaign can be divided into two parts, distinguished by a lower temperature level in the second part of the campaign. The particulate mass concentration showed no significant changes, whereas most of the SVOC had significant higher mean and peak concentrations in the colder period. The analysis of the data showed an increased influence of non-traffic sources in the colder period, reflected by a weak shift in the PAH profile and a significant shift in the hopane pattern. Statistical analysis of the inter-group correlations was carried out. Eight clusters partly representing different sources of the aerosol have been identified.

Formation and aging of secondary organic aerosol from toluene: Changes in chemical composition, volatility, and hygroscopicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hildebrandt Ruiz, L.; Paciga, A. L.; Cerully, K. M.

Secondary organic aerosol (SOA) is transformed after its initial formation, but this chemical aging of SOA is poorly understood. Experiments were conducted in the Carnegie Mellon environmental chamber to form secondary organic aerosol (SOA) from the photo-oxidation of toluene and other small aromatic volatile organic compounds (VOCs) in the presence of NO x under different oxidizing conditions. The effects of the oxidizing condition on organic aerosol (OA) composition, mass yield, volatility, and hygroscopicity were explored. Higher exposure to the hydroxyl radical resulted in different OA composition, average carbon oxidation state (OS c), and mass yield. The OA oxidation state generallymore » increased during photo-oxidation, and the final OA OS c ranged from –0.29 to 0.16 in the performed experiments. The volatility of OA formed in these different experiments varied by as much as a factor of 30, demonstrating that the OA formed under different oxidizing conditions can have a significantly different saturation concentration. In conclusion, there was no clear correlation between hygroscopicity and oxidation state for this relatively hygroscopic SOA.« less

Emission of floral volatiles from Mahonia japonica (Berberidaceae).

PubMed

Picone, Joanne M; MacTavish, Hazel S; Clery, Robin A

2002-07-01

Flowering Mahonia japonica plants were subjected to controlled environments and the floral volatiles emitted from whole racemes (laterals) were trapped by Porapak Q adsorbent and analysed by GC-FID. An experiment with photoperiods of 6 and 9 h at constant temperature (10+/-1 degrees C) demonstrated that photoperiod was the stimulus for enhanced emission of most volatiles. Small quantitative differences in emitted fragrance composition were observed between light and dark periods and between plants acclimatised to different photoperiods. Maximum rates of emission occurred in the middle of the light period; aromatic compounds (benzaldehyde, benzyl alcohol and indole) displayed a more rapid increase and subsequent decline compared with monoterpenes (cis- and trans-ocimene and linalool). When the photoperiod was extended from 6 to 9 h, maximum rates of emission continued throughout the additional 3 h. Total emission (microg/h) of volatiles was 2-fold greater in the day-time (DT) (39.7 microg/h) compared with the night-time (NT) (19.8 microgg/h) under a 6 h photoperiod and was not significantly different from total emission under a 9 h photoperiod.

Formation and aging of secondary organic aerosol from toluene: Changes in chemical composition, volatility, and hygroscopicity

DOE PAGES

Hildebrandt Ruiz, L.; Paciga, A. L.; Cerully, K. M.; ...

2015-07-24

Secondary organic aerosol (SOA) is transformed after its initial formation, but this chemical aging of SOA is poorly understood. Experiments were conducted in the Carnegie Mellon environmental chamber to form secondary organic aerosol (SOA) from the photo-oxidation of toluene and other small aromatic volatile organic compounds (VOCs) in the presence of NO x under different oxidizing conditions. The effects of the oxidizing condition on organic aerosol (OA) composition, mass yield, volatility, and hygroscopicity were explored. Higher exposure to the hydroxyl radical resulted in different OA composition, average carbon oxidation state (OS c), and mass yield. The OA oxidation state generallymore » increased during photo-oxidation, and the final OA OS c ranged from –0.29 to 0.16 in the performed experiments. The volatility of OA formed in these different experiments varied by as much as a factor of 30, demonstrating that the OA formed under different oxidizing conditions can have a significantly different saturation concentration. In conclusion, there was no clear correlation between hygroscopicity and oxidation state for this relatively hygroscopic SOA.« less

Release of volatile and semi-volatile toxicants during house fires.

PubMed

Hewitt, Fiona; Christou, Antonis; Dickens, Kathryn; Walker, Richard; Stec, Anna A

2017-04-01

Qualitative results are presented from analysis of volatile and semi-volatile organic compounds (VOCs/SVOCs) obtained through sampling of gaseous effluent and condensed particulates during a series of experimental house fires conducted in a real house. Particular emphasis is given to the 16 polycyclic aromatic hydrocarbons (PAHs) listed by the Environmental Protection Agency due to their potentially carcinogenic effects. The initial fuel packages were either cooking oil or a single sofa; these were burned both alone, and in furnished surroundings. Experiments were performed at different ventilation conditions. Qualitative Gas Chromatography-Mass Spectrometry (GC-MS) analysis found VOC/SVOC releases in the developing stages of the fires, and benzo(a)pyrene - the most carcinogenic PAH - was found in at least one sampling interval in the majority of fires. A number of phosphorus fire retardants were detected, in both the gaseous effluent and particulates, from fires where the initial fuel source was a sofa. Their release during the fire is significant as they pose toxicological concerns separate from those presented by the PAHs. Copyright © 2016. Published by Elsevier Ltd.

Organic emissions from coal pyrolysis: mutagenic effects.

PubMed Central

Braun, A G; Wornat, M J; Mitra, A; Sarofim, A F

1987-01-01

Four different types of coal have been pyrolyzed in a laminar flow, drop tube furnace in order to establish a relationship between polycyclic aromatic compound (PAC) evolution and mutagenicity. Temperatures of 900K to 1700K and particle residence times up to 0.3 sec were chosen to best simulate conditions of rapid rate pyrolysis in pulverized (44-53 microns) coal combustion. The specific mutagenic activity (i.e., the activity per unit sample weight) of extracts from particulates and volatiles captured on XAD-2 resin varied with coal type according to the order: subbituminous greater than high volatile bituminous greater than lignite greater than anthracite. Total mutagenic activity (the activity per gram of coal pyrolyzed), however, varied with coal type according to the order: high volatile bituminous much greater than subbituminous = lignite much greater than anthracite, due primarily to high organic yield during high volatile bituminous coal pyrolysis. Specific mutagenic activity peaked in a temperature range of 1300K to 1500K and generally appeared at higher temperatures and longer residence times than peak PAC production. PMID:3311724

Evaluation of the glycoside hydrolase activity of a Brettanomyces strain on glycosides from sour cherry (Prunus cerasus L.) used in the production of special fruit beers.

PubMed

Daenen, Luk; Sterckx, Femke; Delvaux, Freddy R; Verachtert, Hubert; Derdelinckx, Guy

2008-11-01

The glycoside hydrolase activity of Saccharomyces cerevisiae and Brettanomyces custersii was examined on sour cherry (Prunus cerasus L.) glycosides with bound volatile compounds. Refermentations by the beta-glucosidase-negative S. cerevisiae strains LD25 and LD40 of sour cherry juice-supplemented beer demonstrated only a moderate increase of volatiles. In contrast, the beta-glucosidase-positive B. custersii strain LD72 showed a more pronounced activity towards glycosides with aliphatic alcohols, aromatic compounds and terpenoid alcohols. Important contributors to sour cherry aroma such as benzaldehyde, linalool and eugenol were released during refermentation as shown by analytical tools. A gradually increasing release was observed during refermentations by B. custersii when whole sour cherries, sour cherry pulp or juice were supplemented in the beer. Refermentations with whole sour cherries and with sour cherry stones demonstrated an increased formation of benzyl compounds. Thus, amygdalin was partially hydrolysed, and a large part of the benzaldehyde formed was mainly reduced to benzyl alcohol and some further esterified to benzyl acetate. These findings demonstrate the importance and interesting role of certain Brettanomyces species in the production of fruit lambic beers such as 'Kriek'.

Rendering plant emissions of volatile organic compounds during sterilization and cooking processes.

PubMed

Bhatti, Z A; Maqbool, F; Langenhove, H V

2014-01-01

The rendering process emits odorous volatile compounds in the atmosphere; if these volatile organic compounds (VOCs) are not handled properly they can cause a serious environmental problem. During this process not all emitted compounds are odorous and hazardous but some of them have been found associated with health problems. Samples were collected in the plastic bags from the Arnout rendering plant. In this study, VOCs emission from two different processes (cooking and sterilization) was compared. For the analysis of various emitted compounds, gas chromatograph and mass spectrophotometer were used. A sterilization process was added in the rendering plant to inactivate the prion protein from meat bone meal prepared during the rendering process. The identification of mass spectrum was performed by using a mass spectral database system. The most odorous classes of compounds identified were aliphatic hydrocarbons (HCs) (29.24%), furans (28.74%), aromatic HCs (18.32%), most important sulphur-containing compounds (12.15%), aldehyde (10.91%) and ketones (0.60%). Emissions released during cooking and sterilization were 32.73 x 10(2) and 36.85 x 10(2) mg m(-3), respectively. In this study, it was observed that after the addition of the sterilization process VOCs' emissions were increased. A total of 87 mg m(-3) dimethyl disulphide (DMS) was detected only during the cooking process, whereas dimethly trisulphide (DMTS) was detected in both cooking (300 mg m(-3)) and sterilization (301 mg m(-3)) processes. About 11 mg m3 of DMS was detected during the cooking process, which was a small concentration compared with 299 mg m(-3) found during the sterilization process. At high temperature and pressure, DMTS and DMS were released more than any other sulphur-containing compounds. A condenser was applied to control the combined emission and it was successful in the reduction of VOCs to 22.83 x 10(2) mg m(-3) (67% reduction).

Potential aromatic compounds as markers to differentiate between Tuber melanosporum and Tuber indicum truffles.

PubMed

Culleré, Laura; Ferreira, Vicente; Venturini, María E; Marco, Pedro; Blanco, Domingo

2013-11-01

The Tuber indicum (Chinese truffle) and Tuber melanosporum (Black truffle) species are morphologically very similar but their aromas are very different. The black truffle aroma is much more intense and complex, and it is consequently appreciated more gastronomically. This work tries to determine whether the differences between the aromatic compounds of both species are sufficiently significant so as to apply them to fraud detection. An olfactometric evaluation (GC-O) of T. indicum was carried out for the first time. Eight important odorants were identified. In order of aromatic significance, these were: 1-octen-3-one and 1-octen-3-ol, followed by two ethyl esters (ethyl isobutyrate and ethyl 2-methylbutyrate), 3-methyl-1-butanol, isopropyl acetate, and finally the two sulfides dimethyldisulfide (DMDS) and dimethylsulfide (DMS). A comparison of this aromatic profile with that of T. melanosporum revealed the following differences: T. indicum stood out for the significant aromatic contribution of 1-octen-3-one and 1-octen-3-ol (with modified frequencies (MF%) of 82% and 69%, respectively), while in the case of T. melanosporum both had modified frequencies of less than 30%. Ethyl isobutyrate, ethyl 2-methylbutyrate and isopropyl acetate were also significantly higher, while DMS and DMDS had low MF (30-40%) compared to T. melanosporum (>70%). The volatile profiles of both species were also studied by means of headspace solid-phase microextraction (HS-SPME-GC-MS). This showed that the family of C8 compounds (3-octanone, octanal, 1-octen-3-one, 3-octanol and 1-octen-3-ol) is present in T. indicum at much higher levels. The presence of 1-octen-3-ol was higher by a factor of about 100, while 1-octen-3-one was detected in T. indicum only (there was no chromatographic signal in T. melanosporum). As well as showing the greatest chromatographic differences, these two compounds were also the most powerful from the aromatic viewpoint in the T. indicum olfactometry. Therefore, either of the two chromatographic methods (GC-O or HS-SPME-GC-MS), together or separately, could be used as a screening technique to distinguish between T. indicum and T. melanosporum and thus avoid possible fraud. Copyright © 2013 Elsevier Ltd. All rights reserved.

Photochemical aging of volatile organic compounds associated with oil and natural gas extraction in the Uintah Basin, UT, during a wintertime ozone formation event

NASA Astrophysics Data System (ADS)

Koss, A. R.; de Gouw, J.; Warneke, C.; Gilman, J. B.; Lerner, B. M.; Graus, M.; Yuan, B.; Edwards, P.; Brown, S. S.; Wild, R.; Roberts, J. M.; Bates, T. S.; Quinn, P. K.

2015-05-01

High concentrations of volatile organic compounds (VOCs) associated with oil and natural gas extraction were measured during a strong temperature inversion in the winter of 2013 at a rural site in the Uintah Basin, Utah. During this period, photochemistry enhanced by the stagnant meteorological conditions and concentrated VOCs led to high ozone mixing ratios (150 ppbv). A simple analysis of aromatic VOCs measured by proton-transfer-reaction mass-spectrometry (PTR-MS) is used to estimate (1) VOC emission ratios (the ratio of two VOCs at the time of emission) relative to benzene, (2) aromatic VOC emission rates, and (3) ambient OH radical concentrations. These quantities are determined from a best fit to VOC : benzene ratios as a function of time. The main findings are that (1) emission ratios are consistent with contributions from both oil and gas producing wells; (2) the emission rate of methane (27-57 x 103 kg methane h-1), extrapolated from the emission rate of benzene (4.1 ± 0.4 x 105 molecules cm-3 s-1), agrees with an independent estimate of methane emissions from aircraft measurements in 2012; and (3) calculated daily OH concentrations are low, peaking at 1 x 106 molecules cm-3, and are consistent with Master Chemical Mechanism (MCM) modeling. The analysis is extended to photochemical production of oxygenated VOCs measured by PTR-MS and is able to explain daytime variability of these species. It is not able to completely reproduce nighttime behavior, possibly due to surface deposition. Using results from this analysis, the carbon mass of secondary compounds expected to have formed by the sixth day of the stagnation event was calculated, then compared to the measured mass of primary and secondary compounds. Only 17% of the expected secondary carbon mass is accounted for by gas phase, aerosol, and snow organic carbon measurements. The disparity is likely due to substantial amounts of unquantified oxygenated products.

Photochemical aging of volatile organic compounds associated with oil and natural gas extraction in the Uintah Basin, UT, during a wintertime ozone formation event

NASA Astrophysics Data System (ADS)

Koss, A. R.; de Gouw, J.; Warneke, C.; Gilman, J. B.; Lerner, B. M.; Graus, M.; Yuan, B.; Edwards, P.; Brown, S. S.; Wild, R.; Roberts, J. M.; Bates, T. S.; Quinn, P. K.

2015-03-01

High concentrations of volatile organic compounds (VOCs) associated with oil and natural gas extraction were measured during a strong temperature inversion in winter of 2013 at a rural site in the Uintah Basin, Utah. During this period, photochemistry enhanced by the stagnant meteorological conditions and concentrated VOCs led to high ozone mixing ratios (150 ppbv). A simple analysis of aromatic VOCs measured by proton-transfer-reaction mass-spectrometry (PTR-MS) is used to estimate (1) VOC emission ratios (the ratio of two VOCs at the time of emission) relative to benzene, (2) aromatic VOC emission rates, and (3) ambient OH radical concentrations. These quantities are determined from a best fit to VOC : benzene ratios as a function of time. The main findings are that (1) emission ratios are consistent with contributions from both oil and gas producing wells, (2) the emission rate of methane (27-57 × 103 kg methane h-1), extrapolated from the emission rate of benzene (4.1 ± 0.4 × 105 molecules cm-3 s-1), agrees with an independent estimate of methane emissions from aircraft measurements in 2012, and (3) calculated daily OH concentrations are low, peaking at 1× 106 molecules cm-3, and are consistent with Master Chemical Mechanism (MCM) modeling. The analysis is extended to photochemical production of oxygenated VOCs measured by PTRMS and is able to explain daytime variability of these species. It is not able to completely reproduce nighttime behavior, possibly due to surface deposition. Using results from this analysis, the carbon mass of secondary compounds expected to have formed by the sixth day of the stagnation event was calculated, then compared to the measured mass of primary and secondary compounds. Only 17% of the expected secondary carbon mass is accounted for by gas phase, aerosol, and snow organic carbon measurements. The disparity is likely due to substantial amounts of unquantified oxygenated products.

Chemosensory characterization of Chardonnay and Pinot Noir base wines of Champagne. Two very different varieties for a common product.

PubMed

Herrero, Paula; Sáenz-Navajas, Pilar; Culleré, Laura; Ferreira, Vicente; Chatin, Amelie; Chaperon, Vincent; Litoux-Desrues, François; Escudero, Ana

2016-09-15

Five different methodologies were applied for the quantitative analysis of 86 volatile molecules in 32 Chardonnay and 30 Pinot Noir Champagne white base wines. Sensory characterization was carried out by descriptive analysis. Pinot Noir wines had more constitutive compounds while Chardonnay wines had more discriminant compounds. Only four compounds predominated in Chardonnay wines: 4-vinylphenol, guaiacol, sotolon and 4-methyl-4-mercapto-2-pentanone. Correlation studies and PLSR models were calculated with sensory and chemical variables. For Pinot Noir wines, they were not as revealing as for Chardonnay base wines. Sulfur-related compounds were suggested to be involved in tropical fruit, dried fruit and citric sensory notes. This family of compounds seemed to be responsible for discriminant sensory terms in Champagne base wines. Fermentative compounds (aromatic buffer) were found at significantly higher levels in Pinot Noir wines, which would explain the fact that these wines were more difficult to describe in comparison with Chardonnay base wines. Copyright © 2016 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The Taylorville Central Illinois Public Service (CIPS) Company site is located on the south end of Taylorville, Christian County, Illinois. Past industrial activities at this site, 60-100 years ago, have resulted in subsurface soil and groundwater contamination by high levels of polynuclear aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Complete pathways at this site include exposure to sediments, surface water, air, and fish in the Seaman Estate Pond. The Illinois Department of Public Health (IDPH) concludes that exposure to site related contaminants to local residents does not pose a health hazard at this time.

High hydrostatic pressure treatments enhance volatile components of pre-germinated brown rice revealed by aromatic fingerprinting based on HS-SPME/GC-MS and chemometric methods.

PubMed

Xia, Qiang; Mei, Jun; Yu, Wenjuan; Li, Yunfei

2017-01-01

Germination favors to significantly enhance functional components and health attributes of whole-grain brown rice (BR), but the production of germinated BR (GBR) compromises the typical rice flavor perception due to soaking process. Simultaneously, high hydrostatic pressure (HHP) is considered as an effective processing technique to enhance micronutrients utilization efficiency of GBR and improve products flavor, but no information about the effects of HHP treatments on volatile fingerprinting of GBR has been reported. Therefore, the objective of this work was to apply HHP to improve the flavor and odor of GBR grains by exploring HHP-induced changes in aroma compounds. GBR grains were obtained by incubating at 37°C for 36h, and subsequently subjected to HHP treatments at pressures 100, 300 and 500MPa for 15min, using 0.1MPa as control. Headspace solid-phase micro extraction coupled to gas chromatography mass spectrometry was used to characterize process-induced shifts of volatile organic compounds fingerprinting, followed by multivariate analysis. Our results confirmed the significant reduction of total volatile fractions derived from germination process. Contrarily, the following HHP treatments greatly enhanced the flavor components of GBR, particularly characteristic odorants including aldehydes, ketones, and alcohols. Principal component analysis further indicated the different influence of germination and high pressure on the changes in volatile components. Partial least square-discrimination analysis suggested that 4-vinylguaiacol was closely linked to germination, whereas E,E-2,4-decadienal, E-2-hexenal, E,E-2,4-heptadienal and benzyl alcohol could be considered as volatile biomarkers of high pressure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparision of real waste (MSW and MPW) pyrolysis in batch reactor over different catalysts. Part I: product yields, gas and pyrolysis oil properties.

PubMed

Ateş, Funda; Miskolczi, Norbert; Borsodi, Nikolett

2013-04-01

Pyrolysis of municipal solid waste (MSW) and municipal plastic waste (MPW) have been investigated in batch reactor at 500, 550 and 600°C both in absence and presence of catalysts (Y-zeolite, β-zeolite, equilibrium FCC, MoO3, Ni-Mo-catalyst, HZSM-5 and Al(OH)3). The effect of the parameters on the product properties was investigated. Products were characterized using gas-chromatography, GC/MS, (13)C NMR. Yields of volatile fractions increased, while reaction time necessity for the total cracking decreased in the presence of catalysts. Catalysts have productivity and selectivity in converting aliphatic hydrocarbons to aromatic and cyclic compounds in oil products. Gases from MSW consisted of hydrogen CO, CO2, while exclusively hydrogen and hydrocarbons were detected from MPW. Catalyst efficiency was higher using MPW than MSW. Pyrolysis oils contained aliphatic hydrocarbons, aromatics, cyclic compounds and less ketones, alcohols, acids or esters depending on the raw materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization of VOC Sources during the Texas Air Quality Study 2000 Using Proton-Transfer-Reaction Mass Spectrometry

NASA Astrophysics Data System (ADS)

Karl, T.; Jobson, T.; William, K.; Williams, E.; Stutz, J.; Goldan, P.; Fall, R.; Fehsenfeld, F.; Lindinger, W.

2002-12-01

We used Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) for continuous real-time monitoring of volatile organic compounds (VOCs) at a site near the Houston Ship Channel during the Texas Air Quality Study 2000. Anthropogenic aromatics, alkenes, methanol, acetaldehyde, formaldehyde, acetone/propanal, a C7-Ketone, HCN and acrylonitrile were the most prominent compounds observed. Propene was the most abundant light-weight hydrocarbon detected by this technique, and was highly correlated with its oxidation products, formaldehyde and acetaldehyde, with typical propene-acetaldehyde ratios close to 1 in propene-dominated plumes. In the case of aromatic species the high time resolution of the obtained dataset helped in identifying different anthropogenic sources (e.g. industrial from urban emissions) and testing current emission inventories. In addition, a comparison with results from complimentary techniques (gas chromatography, differential optical absorption spectroscopy) was used to assess the selectivity of this on-line technique in a complex urban and industrial VOC matrix and give an interpretation of mass scans obtained by `soft' chemical ionization using proton-transfer via H3O+.

PTR-TOF-MS measurements of atmospheric VOCs during the CALNEX 2010 campaign

NASA Astrophysics Data System (ADS)

Vlasenko, A. L.; Li, S.; Bon, D.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.

2010-12-01

During the CALNEX 2010 study, in-situ volatile organic compounds (VOCs) measurements were made aboard the WHOI research vessel Atlantis by a high resolution proton transfer mass spectrometer (PTR-TOF-MS, Ionicon Analytik). The PTR-TOF-MS was deployed along with a GC-FID system during cruise along the California coast and inside port areas to characterize atmospheric levels and chemical transformation of the extensive set of VOCs in marine boundary layer, in particular, in situations where outflows of pollutants from the major urban centers along the coast occur, and to probe the interactions of the anthropogenic pollutants with marine atmosphere. One minute average scans were collected over a period of 24 days. Several offshore outflow episodes were identified by the increasing mixing ratios of aromatic compounds, such as benzene, toluene and C8-aromatics. Preliminary analysis suggests a relatively rapid removal of these species as a result of photochemical aging over a time scale of hours during sunrise. The observed rates of removal correspond reasonably well with those expected from OH photochemistry. Data demonstrating all of these conclusions will be shown.

Aerial Sampling of Emissions from Biomass Pile Burns in ...

EPA Pesticide Factsheets

Abstract (already cleared). Emissions from burning piles of post-harvest timber slash in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5 µm), black carbon, ultraviolet absorbing PM, elemental/organic carbon, semi-volatile organics (polycyclic aromatic hydrocarbons and polychlorinated dibenzodioxins/dibenzofurans), filter-based metals, and volatile organics were sampled for determination of emission factors. The effect on emissions from covering or not covering piles with polyethylene sheets to prevent fuel wetting was determined. Results showed that the uncovered (“wet”) piles burned with lower combustion efficiency and higher emissions of volatile organic compounds. Results for other pollutants will also be discussed. This work determines the first known in-field emission factors for burning of timber slash piles. The results also document the effect on emissions of covering the piles with polyethylene covers to reduce the moisture content of the biomass.

Outdoor passive air monitoring of semi volatile organic compounds (SVOCs): a critical evaluation of performance and limitations of polyurethane foam (PUF) disks.

PubMed

Bohlin, P; Audy, O; Škrdlíková, L; Kukučka, P; Přibylová, P; Prokeš, R; Vojta, Š; Klánová, J

2014-03-01

The most commonly used passive air sampler (PAS) (i.e. polyurethane foam (PUF) disk) is cheap, versatile, and capable of accumulating compounds present both in gas and particle phases. Its performance for particle associated compounds is however disputable. In this study, twelve sets of triplicate PUF-PAS were deployed outdoors for exposure periods of 1-12 weeks together with continuously operated active samplers, to characterize sampling efficiency and derive sampling rates (RS) for compounds belonging to 7 SVOC classes (including particle associated compounds). PUF-PAS efficiently and consistently sampled polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and eight novel brominated flame retardant (nBFR) compounds. Low accuracy and lack of sensitivity was observed for most polychlorinated dibenzo-p-dioxins/furans PCDD/Fs and polybrominated diphenyl ethers (PBDEs) (under the conditions of this study), with the exception of some congeners which may be used as qualitative markers for their respective classes. Application of compound specific RS was found crucial for all compounds except PCBs. Sampling efficiency of the particle associated compounds was often low.

Intermediate Volatility Organic Compound Emissions from On-Road Gasoline Vehicles and Small Off-Road Gasoline Engines.

PubMed

Zhao, Yunliang; Nguyen, Ngoc T; Presto, Albert A; Hennigan, Christopher J; May, Andrew A; Robinson, Allen L

2016-04-19

Dynamometer experiments were conducted to characterize the intermediate volatility organic compound (IVOC) emissions from a fleet of on-road gasoline vehicles and small off-road gasoline engines. IVOCs were quantified through gas chromatography/mass spectrometry analysis of adsorbent samples collected from a constant volume sampler. The dominant fraction (>80%, on average) of IVOCs could not be resolved on a molecular level. These unspeciated IVOCs were quantified as two chemical classes (unspeciated branched alkanes and cyclic compounds) in 11 retention-time-based bins. IVOC emission factors (mg kg-fuel(-1)) from on-road vehicles varied widely from vehicle to vehicle, but showed a general trend of lower emissions for newer vehicles that met more stringent emission standards. IVOC emission factors for 2-stroke off-road engines were substantially higher than 4-stroke off-road engines and on-road vehicles. Despite large variations in the magnitude of emissions, the IVOC volatility distribution and chemical characteristics were consistent across all tests and IVOC emissions were strongly correlated with nonmethane hydrocarbons (NMHCs), primary organic aerosol and speciated IVOCs. Although IVOC emissions only correspond to approximately 4% of NMHC emissions from on-road vehicles over the cold-start unified cycle, they are estimated to produce as much or more SOA than single-ring aromatics. Our results clearly demonstrate that IVOCs from gasoline engines are an important class of SOA precursors and provide observational constraints on IVOC emission factors and chemical composition to facilitate their inclusion into atmospheric chemistry models.

Changes in the Aromatic Profile, Sugars, and Bioactive Compounds When Purple Garlic Is Transformed into Black Garlic.

PubMed

Martínez-Casas, Lucía; Lage-Yusty, María; López-Hernández, Julia

2017-12-13

Black garlic is an elaborated product obtained from fresh garlic (Allium sativum L.) at a controlled high humidity and temperature, which leads to modifications in color, taste, and texture. To clarify the physicochemical changes that occur during the thermal process, this work aimed to evaluate and contrast the antioxidant capacity and that of other compounds between purple garlic ecotype "Purple from Las Pedroñeras" and its black garlic derivative. Our results showed numerous differences between both, because black garlic presented a significant divergence in its volatile profile, a decreased amount of ascorbic acid, an increment in sugar and polyphenol contents, a greater antioxidant capacity, and a different composition of phenolic acids and flavonoids.

Use of a heated graphite scrubber as a means of reducing interferences in UV-absorbance measurements of atmospheric ozone

NASA Astrophysics Data System (ADS)

Turnipseed, Andrew A.; Andersen, Peter C.; Williford, Craig J.; Ennis, Christine A.; Birks, John W.

2017-06-01

A new solid-phase scrubber for use in conventional ozone (O3) photometers was investigated as a means of reducing interferences from other UV-absorbing species and water vapor. It was found that when heated to 100-130 °C, a tubular graphite scrubber efficiently removed up to 500 ppb ozone and ozone monitors using the heated graphite scrubber were found to be less susceptible to interferences from water vapor, mercury vapor, and aromatic volatile organic compounds (VOCs) compared to conventional metal oxide scrubbers. Ambient measurements from a graphite scrubber-equipped photometer and a co-located Federal equivalent method (FEM) ozone analyzer showed excellent agreement over 38 days of measurements and indicated no loss in the scrubber's ability to remove ozone when operated at 130 °C. The use of a heated graphite scrubber was found to reduce the interference from mercury vapor to ≤ 3 % of that obtained using a packed-bed Hopcalite scrubber. For a series of substituted aromatic compounds (ranging in volatility and absorption cross section at 253.7 nm), the graphite scrubber was observed to consistently exhibit reduced levels of interference, typically by factors of 2.5 to 20 less than with Hopcalite. Conventional solid-phase scrubbers also exhibited complex VOC adsorption and desorption characteristics that were dependent upon the relative humidity (RH), volatility of the VOC, and the available surface area of the scrubber. This complex behavior involving humidity is avoided by use of a heated graphite scrubber. These results suggest that heated graphite scrubbers could be substituted in most ozone photometers as a means of reducing interferences from other UV-absorbing species found in the atmosphere. This could be particularly important in ozone monitoring for compliance with the United States (U.S.) Clean Air Act or for use in VOC-rich environments such as in smog chambers and monitoring indoor air quality.

EPDM plasticizers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Godail, M.J.

1983-08-01

The properties of paraffinic, naphthenic, and aromatic extender oils used as EPDM plasticizers are discussed in detail. Particular attention is given to viscosity, volatility, specific gravity, and aromatic content.

Characterization of volatile profile from ten different varieties of Chinese jujubes by HS-SPME/GC-MS coupled with E-nose.

PubMed

Chen, Qinqin; Song, Jianxin; Bi, Jinfeng; Meng, Xianjun; Wu, Xinye

2018-03-01

Volatile profile of ten different varieties of fresh jujubes was characterized by HS-SPME/GC-MS (headspace solid phase micro-extraction combined with gas chromatography-mass spectrometry) and E-nose (electronic nose). GC-MS results showed that a total of 51 aroma compounds were identified in jujubes, hexanoic acid, hexanal, (E)-2-hexenal, (Z)-2-heptenal, benzaldehyde and (E)-2-nonenal were the main aroma components with contributions that over 70%. Differentiation of jujube varieties was conducted by cluster analysis of GC-MS data and principal component analysis & linear discriminant analysis of E-nose data. Both results showed that jujubes could be mainly divided into two groups: group A (JZ, PDDZ, JSXZ and LWZZ) and group B (BZ, YZ, MZ, XZ and DZ). There were significant differences in contents of alcohols, acids and aromatic compounds between group A and B. GC-MS coupled with E-nose could be a fast and accurate method to identify the general flavor difference in different varieties of jujubes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of γ-irradiation on the physicochemical and sensory properties of hazelnuts ( Corylus avellana L.)

NASA Astrophysics Data System (ADS)

Mexis, S. F.; Kontominas, M. G.

2009-06-01

The present study evaluated the quality of hazelnuts as a function of irradiation dose to determine dose levels causing minimal undesirable changes to hazelnuts. Physicochemical (color, peroxide value (PV), hexanal content, fatty acid composition and volatile compounds) and sensory (color, texture, odor and taste) properties were determined. Results showed a twenty fold increase in peroxide value and twenty-eight fold increase in hexanal content after irradiation at a dose of 7 kGy. An increase was also observed in saturated fatty acids (10%-23%) with a parallel decrease in unsaturated fatty acids (90-77%). Volatile compounds such as ketones, alkanes, alcohols, aldehydes, furans, aromatic hydrocarbons, bicyclic monoterpenes and acids were produced mostly comprising secondary oxidation products of hazelnut lipids after irradiation. Color parameter b* increased ( p<0.05) after irradiation at a dose of ⩾5 kGy, while color parameters L* and a* remained unchanged by irradiation. Sensory evaluation showed that texture and color were not affected by irradiation. Taste, the most sensitive sensory attribute showed that hazelnuts retain acceptable sensory quality when irradiated up to a dose of 1.5 kGy.

Characterization of the volatile organic compounds present in the headspace of decomposing human remains.

PubMed

Hoffman, Erin M; Curran, Allison M; Dulgerian, Nishan; Stockham, Rex A; Eckenrode, Brian A

2009-04-15

Law enforcement agencies frequently use canines trained to detect the odor of human decomposition to aid in determining the location of clandestine burials and human remains deposited or scattered on the surface. However, few studies attempt to identify the specific volatile organic compounds (VOCs) that elicit an appropriate response from victim recovery (VR) canines. Solid-phase microextraction (SPME) was combined with gas chromatography-mass spectrometry (GC-MS) to identify the VOCs released into the headspace associated with 14 separate tissue samples of human remains previously used for VR canine training. The headspace was found to contain various classes of VOCs, including acids, alcohols, aldehydes, halogens, aromatic hydrocarbons, ketones, and sulfides. Analysis of the data indicates that the VOCs associated with human decomposition share similarities across regions of the body and across types of tissue. However, sufficient differences exist to warrant VR canine testing to identify potential mimic odor chemical profiles that can be used as training aids. The resulting data will assist in the identification of the most suitable mixture and relative concentrations of VOCs to appropriately train VR canines.

Emission Rates of Volatile Organic Compounds Released from Newly Produced Household Furniture Products Using a Large-Scale Chamber Testing Method

PubMed Central

Ho, Duy Xuan; Kim, Ki-Hyun; Ryeul Sohn, Jong; Hee Oh, Youn; Ahn, Ji-Won

2011-01-01

The emission rates of volatile organic compounds (VOCs) were measured to investigate the emission characteristics of five types of common furniture products using a 5 m3 size chamber at 25°C and 50% humidity. The results indicated that toluene and α-pinene are the most dominant components. The emission rates of individual components decreased constantly through time, approaching the equilibrium emission level. The relative ordering of their emission rates, if assessed in terms of total VOC (TVOC), can be arranged as follows: dining table > sofa > desk chair > bedside table > cabinet. If the emission rates of VOCs are examined between different chemical groups, they can also be arranged in the following order: aromatic (AR) > terpenes (TER) > carbonyl (CBN) > others > paraffin (PR) > olefin (HOL) > halogenated paraffin (HPR). In addition, if emission strengths are compared between coated and uncoated furniture, there is no significant difference in terms of emission magnitude. Our results indicate that the emission characteristics of VOC are greatly distinguished between different furniture products in terms of relative dominance between different chemicals. PMID:22125421

Can scooter emissions dominate urban organic aerosol?

NASA Astrophysics Data System (ADS)

El Haddad, Imad; Platt, Stephen; Huang, Ru-Jin; Zardini, Alessandro; Clairotte, Micheal; Pieber, Simone; Pfaffenberger, Lisa; Fuller, Steve; Hellebust, Stig; Temime-Roussel, Brice; Slowik, Jay; Chirico, Roberto; Kalberer, Markus; Marchand, Nicolas; Dommen, Josef; Astorga, Covadonga; Baltensperger, Urs; Prevot, Andre

2014-05-01

In urban areas, where the health impact of pollutants increases due to higher population density, traffic is a major source of ambient organic aerosol (OA). A significant fraction of OA from traffic is secondary, produced via the reaction of exhaust volatile organic compounds (VOCs) with atmospheric oxidants. Secondary OA (SOA) has not been systematically assessed for different vehicles and driving conditions and thus its relative importance compared to directly emitted, primary OA (POA) is unknown, hindering the design of effective vehicle emissions regulations. 2-stroke (2S) scooters are inexpensive and convenient and as such a popular means of transportation globally, particularly in Asia. European regulations for scooters are less stringent than for other vehicles and thus primary particulate emissions and SOA precursor VOCs from 2S engines are estimated to be much higher. Assessing the effects of scooters on public health requires consideration of both POA, and SOA production. Here, we quantify POA emission factors and potential SOA EFs from 2S scooters, and the effect of using aromatic free fuel instead of standard gasoline thereon. During the tests, Euro 1 and Euro 2 2S scooters were run in idle or simulated low power conditions. Emissions from a Euro 2 2S scooter were also sampled during regulatory driving cycles on a chassis dynamometer. Vehicle exhaust was introduced into smog chambers, where POA emission and SOA production were quantified using a high-resolution time-of-flight aerosol mass spectrometer. A high resolution proton transfer time-of-flight mass spectrometer was used to investigate volatile organic compounds and a suite of instruments was utilized to quantify CO, CO2, O3, NOX and total hydrocarbons. We show that the oxidation of VOCs in the exhaust emissions of 2S scooters produce significant SOA, exceeding by up to an order of magnitude POA emissions. By monitoring the decay of VOC precursors, we show that SOA formation from 2S scooter emissions essentially stems from the condensation of aromatic oxidation products. Further, we demonstrate that replacing the standard gasoline with an aromatic-free fuel mitigates SOA production, underlining the major role of aromatic compounds from 2S exhaust on SOA production. POA and potential SOA EFs determined here from 2S scooters will be presented and compared with EF from other vehicles, including 4-stroke scooters, gasoline cars and diesel cars to assess the contributions of 2S scooters in urban atmospheres.

Resolving the chemical structures of off-odorants and potentially harmful substances in toys-example of children's swords.

PubMed

Denk, Philipp; Velasco-Schön, Cristina; Buettner, Andrea

2017-09-01

Most children's toys on the market are primarily made out of plastic and other complex composite materials. Consumer complaints about offensive odors or irritating effects associated with toy products have increased in recent years. One example is the strongly perceivable negative odor reported for a particular series of toy swords. Characterizing the presence of contaminants, including those that have the potential to be deleterious to health, in such products is a significant analytical challenge due to the high baseline abundance of chemical constituents of the materials used in the products. In the present study, the nature of offensive odorants associated with toy sword products was examined by gas chromatography (GC). After initial sensory evaluations, the volatile compounds from the toy products were recovered using solvent extraction and solvent-assisted flavor evaporation. The extracts were analyzed using GC-olfactometry (GC-O) and two-dimensional GC-O coupled with mass spectrometry (GC-GC-MS/O). A total of 26 odor-active compounds, including aromatic hydrocarbons and phenols, were identified among numerous non-odorous volatile by-products. These substances also included polycyclic aromatic hydrocarbons, which were analyzed by GC-MS. Representative substances were naphthalene and 1,2-dihydronaphthalene that exhibited moldy, mothball-like odor impressions, and phenol derivatives with leather-like, phenolic, horse-stable-like smells. The odorants detected correlated with the assigned attributes from the sensory analyses. This study clearly shows that the detection and identification of such odorous contaminants can provide key indications of potentially harmful yet unknown substances in everyday products such as toys. Graphical abstract ᅟ.

Volatile organic compounds in Tijuana during the Cal-Mex 2010 campaign: Measurements and source apportionment

NASA Astrophysics Data System (ADS)

Zheng, Jun; Garzón, Jessica P.; Huertas, María E.; Zhang, Renyi; Levy, Misti; Ma, Yan; Huertas, José I.; Jardón, Ricardo T.; Ruíz, Luis G.; Tan, Haobo; Molina, Luisa T.

2013-05-01

As part of the Cal-Mex 2010 air quality study, a proton transfer reaction-mass spectrometer (PTR-MS) was deployed at the San Diego-Tijuana border area to measure volatile organic compounds (VOCs) from 15 May to 30 June 2010. The major VOCs identified during the study included oxygenated VOCs (e.g., methanol, acetaldehyde, acetone, and methyl ethyl ketone) and aromatics (e.g., benzene, toluene, C8- and C9-aromatics). Biogenic VOCs (e.g., isoprene) were scarce in this region because of the lack of vegetation in this arid area. Using an U.S. EPA positive matrix factorization model, VOCs together with other trace gases (NOx, NOz and SO2) observed in this border region were attributed to four types of sources, i.e., local industrial solvent usage (58% in ppbC), gasoline vehicle exhaust (19% in ppbC), diesel vehicle exhaust (14% in ppbC), and aged plume (9% in ppbC) due to regional background and/or long-range transport. Diesel vehicle emission contributed to 87% of SO2 and 75% of NOx, and aged plume contributed to 92% of NOz. An independent conditional probability function analysis of VOCs, wind direction, and wind speed indicated that the industrial source did not show a significant tendency with wind direction. Both gasoline and diesel engine emissions were associated with air masses passing through two busy cross-border ports. Aged plumes were strongly associated with NW wind, which likely brought in aged air masses from the populated San Diego area.

Phytochemical Profiles and Antimicrobial Activities of Allium cepa Red cv. and A. sativum Subjected to Different Drying Methods: A Comparative MS-Based Metabolomics.

PubMed

Farag, Mohamed A; Ali, Sara E; Hodaya, Rashad H; El-Seedi, Hesham R; Sultani, Haider N; Laub, Annegret; Eissa, Tarek F; Abou-Zaid, Fouad O F; Wessjohann, Ludger A

2017-05-08

Plants of the Allium genus produce sulphur compounds that give them a characteristic (alliaceous) flavour and mediate for their medicinal use. In this study, the chemical composition and antimicrobial properties of Allium cepa red cv. and A. sativum in the context of three different drying processes were assessed using metabolomics. Bulbs were dried using either microwave, air drying, or freeze drying and further subjected to chemical analysis of their composition of volatile and non-volatile metabolites. Volatiles were collected using solid phase micro-extraction (SPME) coupled to gas chromatography-mass spectrometry (GC/MS) with 42 identified volatiles including 30 sulphur compounds, four nitriles, three aromatics, and three esters. Profiling of the polar non-volatile metabolites via ultra-performance liquid chromatography coupled to high resolution MS (UPLC/MS) annotated 51 metabolites including dipeptides, flavonoids, phenolic acids, and fatty acids. Major peaks in GC/MS or UPLC/MS contributing to the discrimination between A. sativum and A. cepa red cv. were assigned to sulphur compounds and flavonoids. Whereas sulphur conjugates amounted to the major forms in A. sativum , flavonoids predominated in the chemical composition of A. cepa red cv. With regard to drying impact on Allium metabolites, notable and clear separations among specimens were revealed using principal component analysis (PCA). The PCA scores plot of the UPLC/MS dataset showed closer metabolite composition of microwave dried specimens to freeze dried ones, and distant from air dried bulbs, observed in both A. cepa and A. sativum . Compared to GC/MS, the UPLC/MS derived PCA model was more consistent and better in assessing the impact of drying on Allium metabolism. A phthalate derivative was found exclusively in a commercial garlic preparation via GC/MS, of yet unknown origin. The freeze dried samples of both Allium species exhibited stronger antimicrobial activities compared to dried specimens with A. sativum being in general more active than A. cepa red cv.

Secondary organic aerosol formation and composition from the photo-oxidation of methyl chavicol (estragole)

NASA Astrophysics Data System (ADS)

Pereira, K. L.; Hamilton, J. F.; Rickard, A. R.; Bloss, W. J.; Alam, M. S.; Camredon, M.; Muñoz, A.; Vázquez, M.; Borrás, E.; Ródenas, M.

2014-06-01

The increasing demand for palm oil for uses in biofuel and food products is leading to rapid expansion of oil palm agriculture. Methyl chavicol (also known as estragole and 1-allyl-4-methoxybenzene) is an oxygenated biogenic volatile organic compound (VOC) that was recently identified as the main floral emission from an oil palm plantation in Malaysian Borneo. The emissions of methyl chavicol observed may impact regional atmospheric chemistry, but little is known of its ability to form secondary organic aerosol (SOA). The photo-oxidation of methyl chavicol was investigated at the European Photoreactor chamber as a part of the atmospheric chemistry of methyl chavicol (ATMECH) project. Aerosol samples were collected using a particle into liquid sampler (PILS) and analysed offline using an extensive range of instruments including; high-performance liquid chromatography mass spectrometry (HPLC-ITMS), high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The SOA yield was determined as 18 and 29% for an initial VOC mixing ratio of 212 and 460 ppbv (parts per billion by volume) respectively; using a VOC:NOx ratio of ~5:1. In total, 59 SOA compounds were observed and the structures of 10 compounds have been identified using high-resolution tandem mass spectrometry. The addition of hydroxyl and/or nitro-functional groups to the aromatic ring appears to be an important mechanistic pathway for aerosol formation. This results in the formation of compounds with both low volatility and high O:C ratios, where functionalisation rather than fragmentation is mainly observed as a result of the stability of the ring. The SOA species observed can be characterised as semi-volatile to low-volatility oxygenated organic aerosol (SVOOA and LVOOA) components and therefore may be important in aerosol formation and growth.

Chemical quality of water, sediment, and fish in Mountain Creek Lake, Dallas, Texas, 1994-97

USGS Publications Warehouse

Van Metre, Peter C.; Jones, S.A.; Moring, J. Bruce; Mahler, B.J.; Wilson, Jennifer T.

2003-01-01

The occurrence, trends, and sources of numerous inorganic and organic contaminants were evaluated in Mountain Creek Lake, a reservoir in Dallas, Texas. The study, done in cooperation with the Southern Division Naval Facilities Engineering Command, was prompted by the Navy’s concern for potential off-site migration of contaminants from two facilities on the shore of Mountain Creek Lake, the Naval Air Station Dallas and the Naval Weapons Industrial Reserve Plant. Sampling of stormwater (including suspended sediment), lake water, bottom sediment (including streambed sediment), and fish was primarily in Mountain Creek Lake but also was in stormwater outfalls from the Navy facilities, nearby urban streams, and small streams draining the Air Station.Volatile organic compounds, predominantly solvents from the Reserve Plant and fuel-related compounds from the Air Station, were detected in stormwater from both Navy facilities. Fuel-related compounds also were detected in Mountain Creek Lake at two locations, one near the Air Station inlet where stormwater from a part of the Air Station enters the lake and one at the center of the lake. Concentrations of volatile organic compounds at the two lake sites were small, all less than 5 micrograms per liter.Elevated concentrations of cadmium, chromium, copper, lead, mercury, nickel, silver, and zinc, from 2 to 4 times concentrations at background sites and urban reference sites, were detected in surficial bottom sediments in Cottonwood Bay, near stormwater outfalls from the Reserve Plant. Elevated concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls, compared to background and urban reference sites, were detected in surficial sediments in Cottonwood Bay. Elevated concentrations of polycyclic aromatic hydrocarbons, indicative of urban sources, also were detected in Cottonwood Creek, which drains an urbanized area apart from the Navy facilities. Elevated concentrations of polychlorinated biphenyls were detected in two inlets near the Air Station shoreline. Polycyclic aromatic hydrocarbon and heavy metal concentrations near the Air Station shoreline were not elevated compared to urban reference sites.Much larger concentrations of selected heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls were detected in deeper, older sediments than in surficial sediments in Cottonwood Bay. The decreases in concentrations coincide with changes in wastewater discharge practices at the Reserve Plant. Elevated concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls also were detected in older sediments in the Air Station inlet.On the basis of dated sediment cores and contaminant discharge histories, contaminant accumulation rates in Cottonwood Bay were much greater historically than recently. Most heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls that accumulated in the central and eastern parts of Cottonwood Bay appear to have come from the west lagoon on the Reserve Plant. Treated sewage and industrial-process wastewater were discharged to the west lagoon from about 1941 to 1974. Estimated annual contaminant accumulation rates in Cottonwood Bay decreased by from 1 to 2 orders of magnitude after 1974, when most point-source discharges to the west lagoon ceased.Polychlorinated biphenyls were detected in 61 of 62 individual fish-tissue samples. The largest average concentrations were in eviscerated channel catfish and the smallest were in largemouth bass fillets. Polychlorinated biphenyl and selenium concentrations from analyses of this study were large enough to prompt the Texas State Department of Health to issue a fish-possession ban for Mountain Creek Lake in 1996.Suspended sediments in stormwater at the lagoon outfalls and at sites on Cottonwood Creek were sampled and analyzed for major and trace elements, polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls. The suspended sediments from the outfalls contained about the same mixture of heavy metals and organic compounds, in elevated concentrations compared to reference sites, as bottom sediments from the lagoons and surficial bottom sediments in Cottonwood Bay.Diagnostic ratios of polycyclic aromatic hydrocarbons indicate that uncombusted fuel sources contribute to older sediments and that pyrogenic sources of polycyclic aromatic hydrocarbons dominate recently deposited sediments in Cottonwood Bay and along the Air Station shoreline.

Aromatic VOCs global influence in the ozone production

NASA Astrophysics Data System (ADS)

Cabrera-Perez, David; Pozzer, Andrea

2016-04-01

Aromatic hydrocarbons are a subgroup of Volatile Organic Compounds (VOCs) of special interest in the atmosphere of urban and semi-urban areas. Aromatics form a high fraction of VOCs, are highly reactive and upon oxidation they are an important source of ozone. These group of VOCs are released to the atmosphere by processes related to biomass burning and fossil fuel consumption, while they are removed from the atmosphere primarily by OH reaction and by dry deposition. In addition, a branch of aromatics (ortho-nitrophenols) produce HONO upon photolysis, which is responsible of certain amount of the OH recycling. Despite their importance in the atmosphere in anthropogenic polluted areas, the influence of aromatics in the ozone production remains largely unknown. This is of particular relevance, being ozone a pollutant with severe side effects on air quality, health and climate. In this work the atmospheric impacts at global scale of the most emitted aromatic VOCs in the gas phase (benzene, toluene, xylenes, ethylbenzene, styrene, phenol, benzaldehyde and trimethylbenzenes) are analysed and assessed. Specifically, the impact on ozone due to aromatic oxidation is estimated, as this is of great interest in large urban areas and can be helpful for developing air pollution control strategies. Further targets are the quantification of the NOx loss and the OH recycling due to aromatic oxidation. In order to investigate these processes, two simulations were performed with the numerical chemistry and climate simulation ECHAM/MESSy Atmospheric Chemistry (EMAC) model. The simulations compare two cases, one with ozone concentrations when aromatics are present or the second one when they are missing. Finally, model simulated ozone is compared against a global set of observations in order to better constrain the model accuracy.

Degradation of polycyclic aromatic hydrocarbons (PAHs) present in used motor oil and implications for urban runoff quality

NASA Astrophysics Data System (ADS)

Ferreira, M.; Stenstrom, M. K.; Lau, S.

2013-12-01

Polycyclic aromatic hydrocarbons (PAHs) are common organic pollutants of urban stormwater runoff due to atmospheric deposition, vehicle-related discharges, and coal tar pavement sealants. The US EPA lists sixteen PAHs as priority pollutants and seven of those are potential carcinogenic compounds. Due to their molecular structure, PAHs tend to attach to particles that will subsequently be deposited as sediments in waterways. This study focuses on the degradation of PAHs present in used motor oil. Four experimental setups were used to simulate volatilization and photooxidation in the degradation of sixteen PAHs as observed for up to 54 days. The volatilization-only experiment showed substantial reduction only in the concentration of Napthalene (Nap). However, photooxidation-only was more efficient in degrading PAHs. In this process, substantial reduction in the concentrations of Nap, Acenapthene (Anthe), Anthracene (ANT), Fluoranthene (FLT), Pyrene (PYR), Benz[a]anthracene (BaA), Benzo[a]pyrene (BaP), Indeno[1,2,3,cd]pyrene (INP), and Benz[g,h,i]perylene (BghiP) were observed as early as five days. The two volatilization-photooxidation experiments exhibited substantial reduction in the concentrations of Fluorene (FLU), Chrysene (CHR) and Benzo[b]fluoranthene (BbF), in addition to the PAHs reduced by photooxidation-only. Phenanthrene (PHE), Fluoranthene (FLT), and Benzo[b]fluoranthene (BbF) only exhibited substantial decreased concentrations after 20 days in the volatilization-photooxidation experiment. One PAH, acenapthylene (Anthy), was not detected in the original sample of used motor oil. The highest degradations were observed in the combined volatilization-photooxidation experiment. In regions with infrequent rainfall, such as Southern California, molecules of PAHs attached to highway particles will have time to undergo degradation prior to transport. Therefore, PAHs may be present in lower concentrations in highway runoff in dry climates than in rainy climates. To support this hypothesis, a review of highway-related PAHs concentrations is presented.

40 CFR 721.775 - Brominated aromatic com-pound (generic name).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated aromatic com-pound (generic... Specific Chemical Substances § 721.775 Brominated aromatic com-pound (generic name). (a) Chemical... as a brominated aromatic compound (PMN P-84-824) is subject to reporting under this section for the...

A Comparison of Parameterizations of Secondary Organic Aerosol Production: Global Budget and Spatiotemporal Variability

NASA Astrophysics Data System (ADS)

Liu, J.; Chen, Z.; Horowitz, L. W.; Carlton, A. M. G.; Fan, S.; Cheng, Y.; Ervens, B.; Fu, T. M.; He, C.; Tao, S.

2014-12-01

Secondary organic aerosols (SOA) have a profound influence on air quality and climate, but large uncertainties exist in modeling SOA on the global scale. In this study, five SOA parameterization schemes, including a two-product model (TPM), volatility basis-set (VBS) and three cloud SOA schemes (Ervens et al. (2008, 2014), Fu et al. (2008) , and He et al. (2013)), are implemented into the global chemical transport model (MOZART-4). For each scheme, model simulations are conducted with identical boundary and initial conditions. The VBS scheme produces the highest global annual SOA production (close to 35 Tg·y-1), followed by three cloud schemes (26-30 Tg·y-1) and TPM (23 Tg·y-1). Though sharing a similar partitioning theory to the TPM scheme, the VBS approach simulates the chemical aging of multiple generations of VOCs oxidation products, resulting in a much larger SOA source, particularly from aromatic species, over Europe, the Middle East and Eastern America. The formation of SOA in VBS, which represents the net partitioning of semi-volatile organic compounds from vapor to condensed phase, is highly sensitivity to the aging and wet removal processes of vapor-phase organic compounds. The production of SOA from cloud processes (SOAcld) is constrained by the coincidence of liquid cloud water and water-soluble organic compounds. Therefore, all cloud schemes resolve a fairly similar spatial pattern over the tropical and the mid-latitude continents. The spatiotemporal diversity among SOA parameterizations is largely driven by differences in precursor inputs. Therefore, a deeper understanding of the evolution, wet removal, and phase partitioning of semi-volatile organic compounds, particularly above remote land and oceanic areas, is critical to better constrain the global-scale distribution and related climate forcing of secondary organic aerosols.

Emissions of organic compounds from produced water ponds I: Characteristics and speciation.

PubMed

Lyman, Seth N; Mansfield, Marc L; Tran, Huy N Q; Evans, Jordan D; Jones, Colleen; O'Neil, Trevor; Bowers, Ric; Smith, Ann; Keslar, Cara

2018-04-01

We measured fluxes of methane, a suite of non-methane hydrocarbons (C2-C11), light alcohols, and carbon dioxide from oil and gas produced water storage and disposal ponds in Utah (Uinta Basin) and Wyoming (Upper Green River Basin) United States during 2013-2016. In this paper, we discuss the characteristics of produced water composition and air-water fluxes, with a focus on flux chamber measurements. In companion papers, we will (1) report on inverse modeling methods used to estimate emissions from produced water ponds, including comparisons with flux chamber measurements, and (2) discuss the development of mass transfer coefficients to estimate emissions and place emissions from produced water ponds in the context of all regional oil and gas-related emissions. Alcohols (made up mostly of methanol) were the most abundant organic compound group in produced water (91% of total volatile organic concentration, with upper and lower 95% confidence levels of 89 and 93%) but accounted for only 34% (28 to 41%) of total organic compound fluxes from produced water ponds. Non-methane hydrocarbons, which are much less water-soluble than methanol and less abundant in produced water, accounted for the majority of emitted organics. C6-C9 alkanes and aromatics dominated hydrocarbon fluxes, perhaps because lighter hydrocarbons had already volatilized from produced water prior to its arrival in storage or disposal ponds, while heavier hydrocarbons are less water soluble and less volatile. Fluxes of formaldehyde and other carbonyls were low (1% (1 to 2%) of total organic compound flux). The speciation and magnitude of fluxes varied strongly across the facilities measured and with the amount of time water had been exposed to the atmosphere. The presence or absence of ice also impacted fluxes. Copyright © 2017 Elsevier B.V. All rights reserved.

Volatile Organic Compounds (VOCs) in Conventional and High Performance School Buildings in the U.S.

PubMed

Zhong, Lexuan; Su, Feng-Chiao; Batterman, Stuart

2017-01-21

Exposure to volatile organic compounds (VOCs) has been an indoor environmental quality (IEQ) concern in schools and other buildings for many years. Newer designs, construction practices and building materials for "green" buildings and the use of "environmentally friendly" products have the promise of lowering chemical exposure. This study examines VOCs and IEQ parameters in 144 classrooms in 37 conventional and high performance elementary schools in the U.S. with the objectives of providing a comprehensive analysis and updating the literature. Tested schools were built or renovated in the past 15 years, and included comparable numbers of conventional, Energy Star, and Leadership in Energy and Environmental Design (LEED)-certified buildings. Indoor and outdoor VOC samples were collected and analyzed by thermal desorption, gas chromatography and mass spectroscopy for 94 compounds. Aromatics, alkanes and terpenes were the major compound groups detected. Most VOCs had mean concentrations below 5 µg/m³, and most indoor/outdoor concentration ratios ranged from one to 10. For 16 VOCs, the within-school variance of concentrations exceeded that between schools and, overall, no major differences in VOC concentrations were found between conventional and high performance buildings. While VOC concentrations have declined from levels measured in earlier decades, opportunities remain to improve indoor air quality (IAQ) by limiting emissions from building-related sources and by increasing ventilation rates.

Volatile Organic Compounds (VOCs) in Conventional and High Performance School Buildings in the U.S.

PubMed Central

Zhong, Lexuan; Su, Feng-Chiao; Batterman, Stuart

2017-01-01

Exposure to volatile organic compounds (VOCs) has been an indoor environmental quality (IEQ) concern in schools and other buildings for many years. Newer designs, construction practices and building materials for “green” buildings and the use of “environmentally friendly” products have the promise of lowering chemical exposure. This study examines VOCs and IEQ parameters in 144 classrooms in 37 conventional and high performance elementary schools in the U.S. with the objectives of providing a comprehensive analysis and updating the literature. Tested schools were built or renovated in the past 15 years, and included comparable numbers of conventional, Energy Star, and Leadership in Energy and Environmental Design (LEED)-certified buildings. Indoor and outdoor VOC samples were collected and analyzed by thermal desorption, gas chromatography and mass spectroscopy for 94 compounds. Aromatics, alkanes and terpenes were the major compound groups detected. Most VOCs had mean concentrations below 5 µg/m3, and most indoor/outdoor concentration ratios ranged from one to 10. For 16 VOCs, the within-school variance of concentrations exceeded that between schools and, overall, no major differences in VOC concentrations were found between conventional and high performance buildings. While VOC concentrations have declined from levels measured in earlier decades, opportunities remain to improve indoor air quality (IAQ) by limiting emissions from building-related sources and by increasing ventilation rates. PMID:28117727

Structural characterization of graphene layers in various Indian coals by X-Ray Diffraction technique

NASA Astrophysics Data System (ADS)

Manoj, B.; Kunjomana, A. G.

2015-02-01

The results of the structural investigation of three Indian coals showed that, the structural parameters like fa & Lc increased where as interlayer spacing d002 decreased with increase in carbon content, aromaticity and coal rank. These structural parameters change just opposite with increase in volatile matter content. Considering the 'turbostratic' structure for coals, the minimum separation between aromatic lamellae was found to vary between 3.34 to 3.61 A° for these coals. As the aromaticity increased, the interlayer spacing decreased an indication of more graphitization of the sample. Volatile matter and carbon content had a strong influence on the aromaticity, interlayer spacing and stacking height on the sample. The average number of carbon atoms per aromatic lamellae and number of layers in the lamellae was found to be 16-21 and 7-8 for all the samples.

Small-scale hydrous pyrolysis of macromolecular material in meteorites

NASA Astrophysics Data System (ADS)

Sephton, M. A.; Pillinger, C. T.; Gilmour, I.

1998-12-01

The hydrous pyrolysis method, usually performed on several hundred grams of terrestrial rock sample, has been scaled down to accommodate less than two grams of meteorite sample. This technique makes full use of the high yields associated with hydrous pyrolysis experiments and permits the investigation of the meteorite macromolecular material, the major organic component in carbonaceous meteorites. The hydrous pyrolysis procedure transforms the high molecular weight macromolecular material into low molecular weight fragments. The released entities can then be extracted with supercritical fluid extraction. In contrast to the parent structure, the pyrolysis products are amenable for analysis by gas chromatography-based techniques. When subjected to hydrous pyrolysis, two carbonaceous chondrites (Orgueil and Cold Bokkeveld) released generally similar products, which consisted of abundant volatile aromatic and alkyl-substituted aromatic compounds. These results revealed the ability of small-scale hydrous pyrolysis to dissect extraterrestrial macromolecular material and thereby reveal its organic constitution.

Sources of SOA gaseous precursors in contrasted urban environments: a focus on mono-aromatic compounds and intermediate volatility compounds

NASA Astrophysics Data System (ADS)

Salameh, Therese; Borbon, Agnès; Ait-Helal, Warda; Afif, Charbel; Sauvage, Stéphane; Locoge, Nadine; Bonneau, Stéphane; Sanchez, Olivier

2016-04-01

Among Volatile Organic Compounds (VOC), the mono-aromatic compounds so-called BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) and the intermediate volatility organic compounds (IVOC) with C>12 are two remarkable chemical families having high impact on health, as well as on the production of secondary pollutants like secondary organic aerosols (SOA) and ozone. However, the nature and relative importance of their sources and, consequently, their impact on SOA formation at urban scale is still under debate. On the one hand, BTEX observations in urban areas of northern mid-latitudes do not reconcile with emission inventories; the latter pointing to solvent use as the dominant source compared to traffic. Moreover, a recent study by Borbon et al. (2013) has shown an enrichment in the C7-C9 aromatic fraction in Paris atmosphere by a factor of 3 compared to other cities. Causes would be: (i) differences in gasoline composition, (ii) differences in vehicle fleet composition, and (iii) differences in solvent use related sources. On the other hand, many smog chamber studies have highlighted IVOCs as important SOA precursors over the last decade but their origin and importance in urban areas relative to other precursors like BTEX is still poorly addressed. Here we combined large VOC datasets to investigate sources of BTEX and IVOC in contrasted urban areas by source-receptor approaches and laboratory experiments. Ambient data include multi-site speciated ambient measurements of C2 to C17 VOCs (traffic, urban background, and tunnel) from air quality networks (ie. AIRPARIF in Paris) and intensive field campaigns (MEGAPOLI-Paris, TRANSEMED in Beirut and Istanbul, PHOTOPAQ in Brussels). Preliminary results for Paris suggest that traffic dominates BTEX concentrations while traffic and domestic heating for IVOC (>70%). In parallel, the detailed composition of the fuel liquid phase was determined at the laboratory for typical fuels distributed in Ile de France region (diesel, SP95, SP95 E10, and SP98) and was used to constraint evaporative emissions in order to predict the headspace vapour composition (Harley and Coulter-Burke, 2000). Modelled and observed compositions are in good agreement (differences up to 20%). Therefore, the implemented model is a relevant tool to test the sensitivity of BTEX and other VOCs ambient composition to evaporative emissions of fuels with regards to their composition. Such analysis will be extended to other target cities and similarities/differences will be presented regarding regional characteristics. This work was supported by the Ile de France region, Life and PHOTOPAQ grant, PICS-CNRS, ENVIMED and ChArMEx. We would like to thank Laurence Dépelchin and Thierry Léonardis for technical support and AIRPARIF for providing the data. Borbon, A., et al. (2013) Emission ratios of anthropogenic VOC in northern mid-latitude megacities: observations vs. emission inventories in Los Angeles and Paris, J. Geophys. Res. 118, 2041 - 2057. Harley, R. and Coulter-Burke, S. (2000) Relating Liquid Fuel and Headspace Vapor Composition for California Reformulated Gasoline Samples Containing Ethanol, Environ. Sci. Technol. 34, 4088-4094. Ait-Helal, W.; Borbon, A.; Sauvage, S.; et al., Atmos. Chem. Phys. vol. 14 , No. 19 , p. 10439-10464

Polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) mitigation in the pyrolysis process of waste tires using CO₂ as a reaction medium.

PubMed

Kwon, Eilhann E; Oh, Jeong-Ik; Kim, Ki-Hyun

2015-09-01

Our work reported the CO2-assisted mitigation of PAHs and VOCs in the thermo-chemical process (i.e., pyrolysis). To investigate the pyrolysis of used tires to recover energy and chemical products, the experiments were conducted using a laboratory-scale batch-type reactor. In particular, to examine the influence of the CO2 in pyrolysis of a tire, the pyrolytic products including C1-5-hydrocarbons (HCs), volatile organic carbons (VOCs), and polycyclic aromatic hydrocarbons (PAHs) were evaluated qualitatively by gas chromatography (GC) with mass spectroscopy (MS) as well as with a thermal conductivity detector (TCD). The mass balance of the pyrolytic products under various pyrolytic conditions was established on the basis of their weight fractions of the pyrolytic products. Our experimental work experimentally validated that the amount of gaseous pyrolytic products increased when using CO2 as a pyrolysis medium, while substantially altering the production of pyrolytic oil in absolute content (7.3-17.2%) and in relative composition (including PAHs and VOCs). Thus, the co-feeding of CO2 in the pyrolysis process can be considered an environmentally benign and energy efficient process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Indoor air quality in two French hospitals: Measurement of chemical and microbiological contaminants.

PubMed

Baurès, Estelle; Blanchard, Olivier; Mercier, Fabien; Surget, Emilie; le Cann, Pierre; Rivier, Alexandre; Gangneux, Jean-Pierre; Florentin, Arnaud

2018-06-09

In addition to being influenced by the environment, the indoor air pollution in hospitals may be associated with specific compounds emitted from various products used, health care activities and building materials. This study has enabled assessment of the chemical and microbiological concentrations of indoor air in two French hospitals. Based on an integrated approach, the methodology defined aims to measure concentrations of a wide range of chemical compounds (>50 volatile and semi-volatile organic compounds), particle concentrations (PM 10 and PM 2.5 ), microorganisms (fungi, bacteria and viruses) and ambient parameters (temperature, relative humidity, pressure and carbon dioxide). Chemical and microbiological air concentrations were measured during two campaigns (winter and summer) and across seven rooms (for spatial variability). The results have shown that indoor air contains a complex mixture of chemical, physical and microbiological compounds. Concentrations in the same order of magnitude were found in both hospitals. Compared to dwelling indoor air, our study shows low, at least equivalent, contamination for non-hospital specific parameters (aldehydes, limonene, phthalates, aromatic hydrocarbons), which is related to ventilation efficiency. Chemical compounds retrieved at the highest concentration and frequencies are due to healthcare activities, for example alcohol - most commonly ethanol - and hand rubbing (median concentration: ethanol 245.7 μg/m 3 and isopropanol 13.6 μg/m 3 ); toluene and staining in parasitology (highest median concentration in Nancy laboratory: 2.1 μg/m 3 )). Copyright © 2018. Published by Elsevier B.V.

Dibasic Ammonium Phosphate Application Enhances Aromatic Compound Concentration in Bog Bilberry Syrup Wine.

PubMed

Wang, Shao-Yang; Li, Yi-Qing; Li, Teng; Yang, Hang-Yu; Ren, Jie; Zhang, Bo-Lin; Zhu, Bao-Qing

2016-12-29

A nitrogen deficiency always causes bog bilberry syrup wine to have a poor sensory feature. This study investigated the effect of nitrogen source addition on volatile compounds during bog bilberry syrup wine fermentation. The syrup was supplemented with 60, 90, 120 or 150 mg/L dibasic ammonium phosphate (DAP) before fermentation. Results showed that an increase of DAP amounts accelerated fermentation rate, increased alcohol content, and decreased sugar level. Total phenol and total flavonoid content were also enhanced with the increase of DAP amounts. A total of 91 volatile compounds were detected in the wine and their concentrations were significantly enhanced with the increase of DAP. Ethyl acetate, isoamyl acetate, phenethyl acetate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, isobutanol, isoamyl alcohol, levo -2,3-butanediol, 2-phenylethanol, meso -2,3-butanediol, isobutyric acid, hexanoic acid, and octanoic acid exhibited a significant increase of their odor activity value (OAV) with the increase of DAP amounts. Bog bilberry syrup wine possessed fruity, fatty, and caramel flavors as its major aroma, whereas a balsamic note was the least present. The increase of DAP amounts significantly improved the global aroma attributes, thereby indicating that DAP supplementation could promote wine fermentation performance and enhance the sensory quality of bog bilberry syrup wine.

Impact of Marcellus Shale natural gas development in southwest Pennsylvania on volatile organic compound emissions and regional air quality.

PubMed

Swarthout, Robert F; Russo, Rachel S; Zhou, Yong; Miller, Brandon M; Mitchell, Brittney; Horsman, Emily; Lipsky, Eric; McCabe, David C; Baum, Ellen; Sive, Barkley C

2015-03-03

The Marcellus Shale is the largest natural gas deposit in the U.S. and rapid development of this resource has raised concerns about regional air pollution. A field campaign was conducted in the southwestern Pennsylvania region of the Marcellus Shale to investigate the impact of unconventional natural gas (UNG) production operations on regional air quality. Whole air samples were collected throughout an 8050 km(2) grid surrounding Pittsburgh and analyzed for methane, carbon dioxide, and C1-C10 volatile organic compounds (VOCs). Elevated mixing ratios of methane and C2-C8 alkanes were observed in areas with the highest density of UNG wells. Source apportionment was used to identify characteristic emission ratios for UNG sources, and results indicated that UNG emissions were responsible for the majority of mixing ratios of C2-C8 alkanes, but accounted for a small proportion of alkene and aromatic compounds. The VOC emissions from UNG operations accounted for 17 ± 19% of the regional kinetic hydroxyl radical reactivity of nonbiogenic VOCs suggesting that natural gas emissions may affect compliance with federal ozone standards. A first approximation of methane emissions from the study area of 10.0 ± 5.2 kg s(-1) provides a baseline for determining the efficacy of regulatory emission control efforts.

Methanogenic biodegradation of charcoal production wastes in groundwater at Kingsford, Michigan, USA

USGS Publications Warehouse

Michael, Godsy E.; Warren, E.; Westjohn, D.B.

2001-01-01

A house exploded in the City of Kingsford, Michigan USA. The explosion was caused by CH4 that leaked into the basement from the surrounding soil. Evidence suggests that biodegradation of products from the distillation and spillage at or near a former wood carbonization plant site was the major source of CH4 and CO2 in the groundwater system. The plant area is directly upgradient from deep groundwater, samples of which are green-yellow in colour, have a very strong odour of burnt wood, contain high concentrations of mononuclear aromatic and phenolic compounds, and extremely high concentrations of volatile fatty acids. The majority of the dissolved compounds in these groundwater samples have been shown, using laboratory microcosms, to be anaerobically biodegradable to CH4 and CO2. The biodegradable compounds, and the amounts of CH4 and CO2 produced in the microcosms, are consistent with observations from field samples.

Synthetic organic compounds and their transformation products in groundwater: occurrence, fate and mitigation.

PubMed

Postigo, Cristina; Barceló, Damià

2015-01-15

Groundwater constitutes the main source of public drinking water supply in many regions. Thus, the contamination of groundwater resources by organic chemicals is a matter of growing concern because of its potential effects on public health. The present manuscript compiles the most recent works related to the study of synthetic organic compounds (SOCs) in groundwater, with special focus on the occurrence of contaminants not or barely covered by previously published reviews, e.g., pesticide and pharmaceutical transformation products, lifestyle products, and industrial chemicals such as corrosion inhibitors, brominated and organophosphate flame retardants, plasticizers, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Moreover, the main challenges in managed aquifer recharge, i.e., reclaimed water injection and infiltration, and riverbank filtration, regarding natural attenuation of organic micropollutants are discussed, and insights into the future chemical quality of groundwater are provided. Copyright © 2014 Elsevier B.V. All rights reserved.

CYP79D enzymes contribute to jasmonic acid-induced formation of aldoximes and other nitrogenous volatiles in two Erythroxylum species.

PubMed

Luck, Katrin; Jirschitzka, Jan; Irmisch, Sandra; Huber, Meret; Gershenzon, Jonathan; Köllner, Tobias G

2016-10-04

Amino acid-derived aldoximes and nitriles play important roles in plant defence. They are well-known as precursors for constitutive defence compounds such as cyanogenic glucosides and glucosinolates, but are also released as volatiles after insect feeding. Cytochrome P450 monooxygenases (CYP) of the CYP79 family catalyze the formation of aldoximes from the corresponding amino acids. However, the majority of CYP79s characterized so far are involved in cyanogenic glucoside or glucosinolate biosynthesis and only a few have been reported to be responsible for nitrogenous volatile production. In this study we analysed and compared the jasmonic acid-induced volatile blends of two Erythroxylum species, the cultivated South American crop species E. coca and the African wild species E. fischeri. Both species produced different nitrogenous compounds including aliphatic aldoximes and an aromatic nitrile. Four isolated CYP79 genes (two from each species) were heterologously expressed in yeast and biochemically characterized. CYP79D62 from E. coca and CYP79D61 and CYP79D60 from E. fischeri showed broad substrate specificity in vitro and converted L-phenylalanine, L-isoleucine, L-leucine, L-tryptophan, and L-tyrosine into the respective aldoximes. In contrast, recombinant CYP79D63 from E. coca exclusively accepted L-tryptophan as substrate. Quantitative real-time PCR revealed that CYP79D60, CYP79D61, and CYP79D62 were significantly upregulated in jasmonic acid-treated Erythroxylum leaves. The kinetic parameters of the enzymes expressed in vitro coupled with the expression patterns of the corresponding genes and the accumulation and emission of (E/Z)-phenylacetaldoxime, (E/Z)-indole-3-acetaldoxime, (E/Z)-3-methylbutyraldoxime, and (E/Z)-2-methylbutyraldoxime in jasmonic acid-treated leaves suggest that CYP79D60, CYP79D61, and CYP79D62 accept L-phenylalanine, L-leucine, L-isoleucine, and L-tryptophan as substrates in vivo and contribute to the production of volatile and semi-volatile nitrogenous defence compounds in E. coca and E. fischeri.

Effects of vehicle type and fuel quality on real world toxic emissions from diesel vehicles

NASA Astrophysics Data System (ADS)

Nelson, Peter F.; Tibbett, Anne R.; Day, Stuart J.

Diesel vehicles are an important source of emissions of air pollutants, particularly oxides of nitrogen (NO x), particulate matter (PM), and toxic compounds with potential health impacts including volatile organic compounds (VOCs) such as benzene and aldehydes, and polycyclic aromatic hydrocarbons (PAHs). Current developments in engine design and fuel quality are expected to reduce these emissions in the future, but many vehicles exceed 10 years of age and may make a major contribution to urban pollutant concentrations and related health impacts for many years. In this study, emissions of a range of toxic compounds are reported using in-service vehicles which were tested using urban driving cycles developed for Australian conditions. Twelve vehicles were chosen from six vehicle weight classes and, in addition, two of these vehicles were driven through the urban drive cycle using a range of diesel fuel formulations. The fuels ranged in sulphur content from 24 to 1700 ppm, and in total aromatics from 7.7 to 33 mass%. Effects of vehicle type and fuel composition on emissions are reported. The results show that emissions of these toxic species were broadly comparable to those observed in previous dynamometer and tunnel studies. Emissions of VOCs and smaller PAHs such as naphthalene, which are derived largely from the combustion process, appear to be related, and show relatively little variability when compared with the variability in emissions of aldehydes and larger PAHs. In particular, aldehyde emissions are highly variable and may be related to engine operating conditions. Fuels of lower sulphur and aromatic content did not have a significant influence on emissions of VOCs and aldehydes, but tended to result in lower emissions of PAHs. The toxicity of vehicle exhaust, as determined by inhalation risk and toxic equivalency factor (TEF)-weighted PAH emissions, was reduced with fuels of lower aromatic content.

Analysis of factors affecting volatile compound formation in roasted pumpkin seeds with selected ion flow tube-mass spectrometry (SIFT-MS) and sensory analysis.

PubMed

Bowman, T; Barringer, S

2012-01-01

Pumpkin (Cucurbita pepo and maxima) seeds are uniquely flavored and commonly consumed as a healthy roasted snack. The objective was to determine dominant volatiles in raw and roasted pumpkin seeds, and the effect of seed coat, moisture content, fatty acid ratio, total lipids, reducing sugars, and harvest year on volatile formation. Sensory was conducted to evaluate overall liking of seed variety and texture. Seed processing included extraction from the fruit, dehydration, and roasting (150 °C). Oil extraction was done using soxhlet, fatty acid profile using Gas Chromatography Flame Ionization Detector, and reducing sugars using 3,5-dinitrosalicylic acid and UV-spectroscopy. Headspace analysis of seeds was performed by selected ion flow tube-mass spectrometry (SIFT-MS). Volatiles dominating in raw pumpkin seeds were lipid aldehydes, ethyl acetate, 2,3-butandione, and dimethylsulfide. Compounds contributing to roasted aroma include alkylpyrazines and Strecker and lipid aldehydes. Overall, hull-less seeds had higher volatile lipid aldehydes and Strecker aldehydes. Seeds dehydrated to a moisture content of 6.5% before roasting had higher initial and final volatile concentrations than seeds starting at 50% moisture. Higher oil content resulted in higher lipid aldehyde formation during roasting with a moderate correlation between free fatty acid ratio and corresponding lipid aldehyde. Harvest year (2009 compared with 2010) had a significant impact on volatile formation in hull-less seeds, but not as much as variety differences. No significant correlation was found between reducing sugars and volatile formation. Sensory showed that hull-less seeds were liked significantly more than hulled seeds. Elucidation of aromatic flavor development during roasting with SIFT-MS provides information on flavor release and offers better control during processing. Knowledge of volatiles in raw and roasted pumpkin seeds and effects of seed coat, moisture content, seed composition, and harvest date will allow for better control over the production/storage/transportation process and a more educated decision during selection of a variety for production of pumpkin seeds in the snack food industry. © 2011 Institute of Food Technologists®

Method of upgrading oils containing hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline

DOEpatents

Baker, E.G.; Elliott, D.C.

1993-01-19

The present invention is a multi-stepped method of converting an oil which is produced by various biomass and coal conversion processes and contains primarily single and multiple ring hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline. The single and multiple ring hydroxyaromatic hydrocarbon compounds in a raw oil material are first deoxygenated to produce a deoxygenated oil material containing single and multiple ring aromatic compounds. Then, water is removed from the deoxygenated oil material. The next step is distillation to remove the single ring aromatic compounds as gasoline. In the third step, the multiple ring aromatics remaining in the deoxygenated oil material are cracked in the presence of hydrogen to produce a cracked oil material containing single ring aromatic compounds. Finally, the cracked oil material is then distilled to remove the single ring aromatics as gasoline.

Influence of different yeast/lactic acid bacteria combinations on the aromatic profile of red Bordeaux wine.

PubMed

Gammacurta, Marine; Marchand, Stéphanie; Moine, Virginie; de Revel, Gilles

2017-09-01

The typical fruity aroma of red Bordeaux wines depends on the grape variety but also on microbiological processes, such as alcoholic and malolactic fermentations. These transformations involve respectively the yeast Saccharomyces cerevisiae and the lactic acid bacterium Oenococcus oeni. Both species play a central role in red winemaking but their quantitative and qualitative contribution to the revelation of the organoleptic qualities of wine has not yet been fully described. The aim of this study was to elucidate the influence of sequential inoculation of different yeast and bacteria strains on the aromatic profile of red Bordeaux wine. All microorganisms completed fermentations and no significant difference was observed between tanks regarding the main oenological parameters until 3 months' aging. Regardless of the yeast strain, B28 bacteria required the shortest period to completely degrade the malic acid, compared to the other strain. Quantification of 73 major components highlighted a specific volatile profile corresponding to each microorganism combination. However, the yeast strain appeared to have a predominant effect on aromatic compound levels, as well as on fruity aroma perception. Yeasts had a greater impact on wine quality and have more influence on the aromatic style of red wine than bacteria. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Evaluation of sediment contamination by monoaromatic hydrocarbons in the coastal lagoons of Gulf of Saros, NE Aegean Sea.

PubMed

Ünlü, Selma; Alpar, Bedri

2017-05-15

The concentrations and distribution of monoaromatic hydrocarbons (benzene, toluene, ethyl benzene and the sum of m-, p- and o-, xylenes) were determined in the sediments of coastal lagoons of the Gulf of Saros, using a static headspace GC-MS. The total concentrations of BTEX compounds ranged from 368.5 to below detection limit 0.6μgkg -1 dw, with a mean value of 61.5μgkg -1 dw. The light aromatic fraction of m-, p-xylene was the most abundant compound (57.1% in average), and followed by toluene (38.1%)>ethylbenzene (4.1%)>o-xylene (2.5%)>benzene (1.1%). The factor analysis indicated that the levels and distribution of BTEX compounds depend on the type of contaminant source (mobile/point), absorbance of compounds in sediment, and mobility of benzene compound and degradation processes. Point sources are mainly related to agricultural facilities and port activities while the dispersion of compounds are related with their solubility, volatility and effect of sea/saline waters on lagoons. Copyright © 2017. Published by Elsevier Ltd.

Simultaneous flame ionization and absorbance detection of volatile and nonvolatile compounds by reversed-phase liquid chromatography with a water mobile phase.

PubMed

Bruckner, C A; Ecker, S T; Synovec, R E

1997-09-01

A flame ionization detector (FID) is used to detect volatile organic compounds that have been separated by water-only reversed-phase liquid chromatography (WRP-LC). The mobile phase is 100% water at room temperature, without use of organic solvent modifiers. An interface between the LC and detector is presented, whereby a helium stream samples the vapor of volatile components from individual drops of the LC eluent, and the vapor-enriched gas stream is sent to the FID. The design of the drop headspace cell is simple because the water-only nature of the LC separation obviates the need to do any organic solvent removal prior to gas phase detection. Despite the absence of organic modifier, hydrophobic compounds can be separated in a reasonable time due to the low phase volume ratio of the WRP-LC columns. The drop headspace interface easily handles LC flows of 1 mL/min, and, in fact, compound detection limits are improved at faster liquid flow rates. The transfer efficiency of the headspace interface was estimated at 10% for toluene in water at 1 mL/min but varies depending on the volatility of each analyte. The detection system is linear over more than 5 orders of 1-butanol concentration in water and is able to detect sub-ppb amounts of o-xylene and other aromatic compounds in water. In order to analyze volatile and nonvolatile analytes simultaneously, the FID is coupled in series to a WRP-LC system with UV absorbance detection. WRP-LC improves UV absorbance detection limits because the absence of organic modifier allows the detector to be operated in the short-wavelength UV region, where analytes generally have significantly larger molar absorptivities. The selectivity the headspace interface provides for flame ionization detection of volatiles is demonstrated with a separation of 1-butanol, 1,1,2-trichloroethane (TCE), and chlorobenzene in a mixture of benzoic acid in water. Despite coelution of butanol and TCE with the benzoate anion, the nonvolatile benzoate anion does not appear in the FID signal, allowing the analytes of interest to be readily detected. The complementary selectivity of UV-visible absorbance detection and this implementation of flame ionization detection allows for the analysis of volatile and nonvolatile components of complex samples using WRP-LC without the requirement that all the components of interest be fully resolved, thus simplifying the sample preparation and chromatographic requirements. This instrument should be applicable to routine automated water monitoring, in which repetitive injection of water samples onto a gas chromatograph is not recommended.

Influence of microwave frequency electromagnetic radiation on terpene emission and content in aromatic plants.

PubMed

Soran, Maria-Loredana; Stan, Manuela; Niinemets, Ülo; Copolovici, Lucian

2014-09-15

Influence of environmental stress factors on both crop and wild plants of nutritional value is an important research topic. The past research has focused on rising temperatures, drought, soil salinity and toxicity, but the potential effects of increased environmental contamination by human-generated electromagnetic radiation on plants have little been studied. Here we studied the influence of microwave irradiation at bands corresponding to wireless router (WLAN) and mobile devices (GSM) on leaf anatomy, essential oil content and volatile emissions in Petroselinum crispum, Apium graveolens and Anethum graveolens. Microwave irradiation resulted in thinner cell walls, smaller chloroplasts and mitochondria, and enhanced emissions of volatile compounds, in particular, monoterpenes and green leaf volatiles (GLV). These effects were stronger for WLAN-frequency microwaves. Essential oil content was enhanced by GSM-frequency microwaves, but the effect of WLAN-frequency microwaves was inhibitory. There was a direct relationship between microwave-induced structural and chemical modifications of the three plant species studied. These data collectively demonstrate that human-generated microwave pollution can potentially constitute a stress to the plants. Copyright © 2014 Elsevier GmbH. All rights reserved.

Aerial sampling of emissions from biomass pile burns in ...

EPA Pesticide Factsheets

Emissions from burning piles of post-harvest timber slash in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5 µm), black carbon, ultraviolet absorbing PM, elemental/organic carbon, semi-volatile organics (polycyclic aromatic hydrocarbons and polychlorinated dibenzodioxins/dibenzofurans), filter-based metals, and volatile organics were sampled for determination of emission factors. The effect on emissions from covering or not covering piles with polyethylene sheets to prevent fuel wetting was determined. Results showed that the uncovered (“wet”) piles burned with lower combustion efficiency and higher emissions of volatile organic compounds. Results for other pollutants will also be discussed. This work determined the emissions from open burning of forest slash wood, with and without plastic sheeting. The foresters advocate the use of plastic to keep the slash wood dry and aid in the controlled combustion of the slash to reduce fuel loading. Concerns about the emissions from the burning plastic prompted this work which conducted an extensive characterization of dry, wet, and dry with plastic slash pile emissions.

Influence of microwave frequency electromagnetic radiation on terpene emission and content in aromatic plants

PubMed Central

Soran, Maria-Loredana; Stan, Manuela; Niinemets, Ülo; Copolovici, Lucian

2015-01-01

Influence of environmental stress factors on both crop and wild plants of nutritional value is an important research topic. The past research has focused on rising temperatures, drought, soil salinity and toxicity, but the potential effects of increased environmental contamination by human-generated electromagnetic radiation on plants have little been studied. Here we studied the influence of microwave irradiation at bands corresponding to wireless router (WLAN) and mobile devices (GSM) on leaf anatomy, essential oil content and volatile emissions in Petroselinum crispum, Apium graveolens and Anethum graveolens. Microwave irradiation resulted in thinner cell walls, smaller chloroplasts and mitochondria, and enhanced emissions of volatile compounds, in particular, monoterpenes and green leaf volatiles. These effects were stronger for WLAN-frequency microwaves. Essential oil content was enhanced by GSM-frequency microwaves, but the effect of WLAN-frequency microwaves was inhibitory. There was a direct relationship between microwave-induced structural and chemical modifications of the three plant species studied. These data collectively demonstrate that human-generated microwave pollution can potentially constitute a stress to the plants. PMID:25050479

Antibacterial and antioxidant activities and chemical compositions of volatile oils extracted from Schisandra chinensis Baill. seeds using simultaneous distillation extraction method, and comparison with Soxhlet and microwave-assisted extraction.

PubMed

Teng, Hui; Lee, Won Y

2014-01-01

The volatile oils were isolated from dried Schisandra chinensis Baill. seeds by Soxhlet extraction (SE), microwave-assisted extraction (MAE), and simultaneous distillation extraction (SDE), and fractions were identified by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). The essential oils were assessed for their antioxidant and antibacterial activities. GC-MS results also revealed that the major ingredients in the oil extracted by SDE were terpenoids compounds such as ylangene (15.01%), α-phellandrene (8.23%), β-himachalene (6.95%), and cuparene (6.74), and the oil extracts of MAE and SE mainly contained aromatics such as schizandrins, wuweizisu C, and gomisin A. HPLC analysis results confirmed that more schizandrin was obtained through extraction by MAE (996.64 μg/g) and SE (722.13 μg/g). SDE oil extract showed more significant antioxidant activity than MAE or SE oil. Only volatile oil from SDE showed good antibacterial activity against all tested strains.

Air quality assessment in Southern Kuwait using diffusive passive samplers.

PubMed

Ramadan, A A

2010-01-01

Measurements of fortnightly average concentrations of NO, NO2, SO2, H2S, NH3, and volatile organic compounds (VOCs) (aromatics=benzene, toluene, o-xylene, m+p-xylene, ethyl benzene; non-aromatics=nonane and octane) were carried out in the period from 26/10/05 to 24/11/05 at 20 points in the southern part of Kuwait as part of a baseline environmental impact assessment study requested by Kuwait National Petroleum Company. Two waves of triplicate diffusive passive samplers were used. A high volume air sampler was used to measure PM10 too. During the sampling period, the wind was observed to be mainly from the west and northwest with an average of 4.28 m/s. The consistency of the results allowed the production of spatial distribution maps of the pollutants measured and consequently the comparison between levels of air pollution at different locations. A comparison between the measured concentrations and the applicable air quality standards promulgated by Kuwait Environment Public Authority (KEPA) showed that those compounds had low concentrations compared to both industrial and residential KEPA standards. For other compounds which are not covered by KEPA standards, the results were compared with relevant limits of US Environment Protect Agency (USEPA) and US Department of Labor, Occupational Safety and Health Administration. The comparison showed that the measured compounds had low concentrations compared to the existing standards and, accordingly, no violation of air quality standards is reported.

First results from the oil sands passive air monitoring network for polycyclic aromatic compounds.

PubMed

Schuster, Jasmin K; Harner, Tom; Su, Ky; Mihele, Cristian; Eng, Anita

2015-03-03

Results are reported from an ongoing passive air monitoring study for polycyclic aromatic compounds (PACs) in the Athabasca oil sands region in Alberta, Canada. Polyurethane foam (PUF) disk passive air samplers were deployed for consecutive 2-month periods from November 2010 to June 2012 at 17 sites. Samples were analyzed for polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, dibenzothiophene and its alkylated derivatives (DBTs). Relative to parent PAHs, alkylated PAHs and DBTs are enriched in bitumen and therefore considered to be petrogenic markers. Concentrations in air were in the range 0.03-210 ng/m(3), 0.15-230 ng/m(3) and 0.01-61 ng/m(3) for ∑PAHs, ∑alkylated PAHs and ΣDBTs, respectively. An exponential decline of the PAC concentrations in air with distance from mining areas and related petrogenic sources was observed. The most significant exponential declines were for the alkylated PAHs and DBTs and attributed to their association with mining-related emissions and near-source deposition, due to their lower volatility and greater association with depositing particles. Seasonal trends in concentrations in air for PACs were not observed for any of the compound classes. However, a forest fire episode during April to July 2011 resulted in greatly elevated PAH levels at all passive sampling locations. Alkylated PAHs and DBTs were not elevated during the forest fire period, supporting their association with petrogenic sources. Based on the results of this study, an "Athabasca PAC profile" is proposed as a potential source marker for the oil sands region. The profile is characterized by ∑PAHs/∑Alkylated PAHs = ∼0.2 and ∑PAHs/∑DBTs = ∼5.

Molecular Characterization of Brown Carbon in Biomass Burning Aerosol Particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Peng; Aiona, Paige K.; Li, Ying

Emissions from biomass burning are a significant source of brown carbon (BrC) in the atmosphere. In this study, we investigate the molecular composition of freshly-emitted biomass burning organic aerosol (BBOA) samples collected during test burns of selected biomass fuels: sawgrass, peat, ponderosa pine, and black spruce. We characterize individual BrC chromophores present in these samples using high performance liquid chromatography coupled to a photodiode array detector and a high-resolution mass spectrometer. We demonstrate that both the overall BrC absorption and the chemical composition of light-absorbing compounds depend significantly on the type of biomass fuels and burning conditions. Common BrC chromophoresmore » in the selected BBOA samples include nitro-aromatics, polycyclic aromatic hydrocarbon derivatives, and polyphenols spanning a wide range of molecular weights, structures, and light absorption properties. A number of biofuel-specific BrC chromophores are observed, indicating that some of them may be used as potential markers of BrC originating from different biomass burning sources. On average, ~50% of the light absorption above 300 nm can be attributed to a limited number of strong BrC chromophores, which may serve as representative light-absorbing species for studying atmospheric processing of BrC aerosol. The absorption coefficients of BBOA are affected by solar photolysis. Specifically, under typical atmospheric conditions, the 300 nm absorbance decays with a half-life of 16 hours. A “molecular corridors” analysis of the BBOA volatility distribution suggests that many BrC compounds in the fresh BBOA have low volatility (<1 g m-1) and will be retained in the particle phase under atmospherically relevant conditions.« less

VOC species and emission inventory from vehicles and their SOA formation potentials estimation in Shanghai, China

NASA Astrophysics Data System (ADS)

Huang, C.; Wang, H. L.; Li, L.; Wang, Q.; Lu, Q.; de Gouw, J. A.; Zhou, M.; Jing, S. A.; Lu, J.; Chen, C. H.

2015-10-01

Volatile organic compound (VOC) species from vehicle exhausts and gas evaporation were investigated by chassis dynamometer and on-road measurements of nine gasoline vehicles, seven diesel vehicles, five motorcycles, and four gas evaporation samples. The secondary organic aerosol (SOA) mass yields of gasoline, diesel, motorcycle exhausts, and gas evaporation were estimated based on the mixing ratio of measured C2-C12 VOC species and inferred carbon number distributions. High aromatic contents were measured in gasoline exhausts and contributed comparatively more SOA yield. A vehicular emission inventory was compiled based on a local survey of on-road traffic in Shanghai and real-world measurements of vehicle emission factors from previous studies in the cities of China. The inventory-based vehicular organic aerosol (OA) productions to total CO emissions were compared with the observed OA to CO concentrations (ΔOA / ΔCO) in the urban atmosphere. The results indicate that vehicles dominate the primary organic aerosol (POA) emissions and OA production, which contributed about 40 and 60 % of OA mass in the urban atmosphere of Shanghai. Diesel vehicles, which accounted for less than 20 % of vehicle kilometers of travel (VKT), contribute more than 90 % of vehicular POA emissions and 80-90 % of OA mass derived by vehicles in urban Shanghai. Gasoline exhaust could be an important source of SOA formation. Tightening the limit of aromatic content in gasoline fuel will be helpful to reduce its SOA contribution. Intermediate-volatile organic compounds (IVOCs) in vehicle exhausts greatly contribute to SOA formation in the urban atmosphere of China. However, more experiments need to be conducted to determine the contributions of IVOCs to OA pollution in China.

Volatile organic compound (VOC) emissions characterization during the flow-back phase of a hydraulically refractured well in the Uintah Basin, Utah using mobile PTR-MS measurements

NASA Astrophysics Data System (ADS)

Geiger, F.; Warneke, C.; Brown, S. S.; De Gouw, J. A.; Dube, W. P.; Edwards, P.; Gilman, J.; Graus, M.; Helleis, F.; Kofler, J.; Lerner, B. M.; Orphal, J.; Petron, G.; Roberts, J. M.; Zahn, A.

2014-12-01

Ongoing improvements in advanced technologies for crude oil and natural gas extraction from unconventional reserves, such as directional drilling and hydraulic fracturing, have greatly increased the production of fossil fuels within recent years. The latest forecasts even estimate an enhancement of 56% in total natural gas production due to increased development of shale gas, tight gas and offshore natural gas resources from 2012 to 2040 with the largest contribution from shale formations [US EIA: Annual Energy Outlook 2014]. During the field intensive 'Energy and Environment - Uintah Basin Winter Ozone Study (UBWOS)', measurements of volatile organic compounds (VOCs) were made using proton-transfer-reactions mass spectrometry (PTR-MS) at the ground site Horse Pool and using a mobile laboratory in the Uintah Basin, Utah, which is a region well known for intense fossil fuel production. A reworked gas well in the Red Wash fields was sampled regularly within two weeks performing mobile laboratory measurements downwind of the well site. The well had been recently hydraulically refractured at that time and waste water was collected into an open flow-back pond. Very high mixing ratios of aromatic hydrocarbons (C6-C13) up to the ppm range were observed coming from condensate and flow-back reservoirs. The measurements are used to determine sources of specific VOC emissions originating from the different parts of the well site and mass spectra are used to classify the air composition in contrast to samples taken at the Horse Pool field site and crude oil samples from South Louisiana. Enhancement ratios and time series of measured peak values for aromatics showed no clear trend, which indicates changes in emissions with operations at the site.

Characterization of Emissions of Volatile Organic Compounds from Interior Alkyd Paint.

PubMed

Fortmann, Roy; Roache, Nancy; Chang, John C S; Guo, Zhishi

1998-10-01

Alkyd paint continues to be used indoors for application to wood trim, cabinet surfaces, and some kitchen and bathroom walls. Alkyd paint may represent a significant source of volatile organic compounds (VOCs) indoors because of the frequency of use and amount of surface painted. The U.S. Environmental Protection Agency (EPA) is conducting research to characterize VOC emissions from paint and to develop source emission models that can be used for exposure assessment and risk management. The technical approach for this research involves both analysis of the liquid paint to identify and quantify the VOC contents and dynamic small chamber emissions tests to characterize the VOC emissions after application. The predominant constituents of the primer and two alkyd paints selected for testing were straight-chain alkanes (C9-C12); C8-C9 aromatics were minor constituents. Branched chain alkanes were the predominant VOCs in a third paint. A series of tests were performed to evaluate factors that may affect emissions following application of the coatings. The type of substrate (glass, wallboard, or pine board) did not have a substantial impact on the emissions with respect to peak concentrations, the emissions profile, or the amount of VOC mass emitted from the paint. Peak concentrations of total volatile organic compounds (TVOCs) as high as 10,000 mg/m 3 were measured during small chamber emissions tests at 0.5 air exchanges per hour (ACH). Over 90% of the VOCs were emitted from the primer and paints during the first 10 hr following application. Emissions were similar from paint applied to bare pine board, a primed board, or a board previously painted with the same paint. The impact of other variables, including film thickness, air velocity at the surface, and air-exchange rate (AER) were consistent with theoretical predictions for gas-phase, mass transfer-controlled emissions. In addition to the alkanes and aromatics, aldehydes were detected in the emissions during paint drying. Hexanal, the predominant aldehyde in the emissions, was not detected in the liquid paint and was apparently an oxidation product formed during drying. This paper summarizes the results of the product analyses and a series of small chamber emissions tests. It also describes the use of a mass balance approach to evaluate the impact of test variables and to assess the quality of the emissions data.

Characterization of emissions of volatile organic compounds from interior alkyd paint.

PubMed

Fortmann, R; Roache, N; Chang, J C; Guo, Z

1998-10-01

Alkyd paint continues to be used indoors for application to wood trim, cabinet surfaces, and some kitchen and bathroom walls. Alkyd paint may represent a significant source of volatile organic compounds (VOCs) indoors because of the frequency of use and amount of surface painted. The U.S. Environmental Protection Agency (EPA) is conducting research to characterize VOC emissions from paint and to develop source emission models that can be used for exposure assessment and risk management. The technical approach for this research involves both analysis of the liquid paint to identify and quantify the VOC contents and dynamic small chamber emissions tests to characterize the VOC emissions after application. The predominant constituents of the primer and two alkyd paints selected for testing were straight-chain alkanes (C9-C12); C8-C9 aromatics were minor constituents. Branched chain alkanes were the predominant VOCs in a third paint. A series of tests were performed to evaluate factors that may affect emissions following application of the coatings. The type of substrate (glass, wallboard, or pine board) did not have a substantial impact on the emissions with respect to peak concentrations, the emissions profile, or the amount of VOC mass emitted from the paint. Peak concentrations of total volatile organic compounds (TVOCs) as high as 10,000 mg/m3 were measured during small chamber emissions tests at 0.5 air exchanges per hour (ACH). Over 90% of the VOCs were emitted from the primer and paints during the first 10 hr following application. Emissions were similar from paint applied to bare pine board, a primed board, or a board previously painted with the same paint. The impact of other variable, including film thickness, air velocity at the surface, and air-exchange rate (AER) were consistent with theoretical predictions for gas-phase, mass transfer-controlled emissions. In addition to the alkanes and aromatics, aldehydes were detected in the emissions during paint drying. Hexanal, the predominant aldehyde in the emissions, was not detected in the liquid paint and was apparently an oxidation product formed during drying. This paper summarizes the results of the product analyses and a series of small chamber emissions tests. It also describes the use of a mass balance approach to evaluate the impact of test variables and to assess the quality of the emissions data.

Observations of VOC Emissions and Photochemical Products over US Oil- and Gas-Producing Regions Using High-Resolution H3O+ CIMS (PTR-ToF-MS)

NASA Technical Reports Server (NTRS)

Koss, Abigail; Yuan, Bin; Warneke, Carsten; Gilman, Jessica B.; Lerner, Brian M.; Veres, Patrick R.; Peischl, Jeff; Eilerman, Scott; Wild, Rob; Brown, Steven S.;

Trypanosoma brucei Inhibition by Essential Oils from Medicinal and Aromatic Plants Traditionally Used in Cameroon (Azadirachta indica, Aframomum melegueta, Aframomum daniellii, Clausena anisata, Dichrostachys cinerea and Echinops giganteus).

PubMed

Kamte, Stephane L Ngahang; Ranjbarian, Farahnaz; Campagnaro, Gustavo Daniel; Nya, Prosper C Biapa; Mbuntcha, Hélène; Woguem, Verlaine; Womeni, Hilaire Macaire; Ta, Léon Azefack; Giordani, Cristiano; Barboni, Luciano; Benelli, Giovanni; Cappellacci, Loredana; Hofer, Anders; Petrelli, Riccardo; Maggi, Filippo

2017-07-06

Essential oils are complex mixtures of volatile components produced by the plant secondary metabolism and consist mainly of monoterpenes and sesquiterpenes and, to a minor extent, of aromatic and aliphatic compounds. They are exploited in several fields such as perfumery, food, pharmaceutics, and cosmetics. Essential oils have long-standing uses in the treatment of infectious diseases and parasitosis in humans and animals. In this regard, their therapeutic potential against human African trypanosomiasis (HAT) has not been fully explored. In the present work, we have selected six medicinal and aromatic plants ( Azadirachta indica , Aframomum melegueta , Aframomum daniellii , Clausena anisata , Dichrostachys cinerea , and Echinops giganteus ) traditionally used in Cameroon to treat several disorders, including infections and parasitic diseases, and evaluated the activity of their essential oils against Trypanosma brucei TC221. Their selectivity was also determined with Balb/3T3 (mouse embryonic fibroblast cell line) cells as a reference. The results showed that the essential oils from A. indica , A . daniellii , and E. giganteus were the most active ones, with half maximal inhibitory concentration (IC 50 ) values of 15.21, 7.65, and 10.50 µg/mL, respectively. These essential oils were characterized by different chemical compounds such as sesquiterpene hydrocarbons, monoterpene hydrocarbons, and oxygenated sesquiterpenes. Some of their main components were assayed as well on T. brucei TC221, and their effects were linked to those of essential oils.

Trypanosoma brucei Inhibition by Essential Oils from Medicinal and Aromatic Plants Traditionally Used in Cameroon (Azadirachta indica, Aframomum melegueta, Aframomum daniellii, Clausena anisata, Dichrostachys cinerea and Echinops giganteus)

PubMed Central

Ngahang Kamte, Stephane L.; Ranjbarian, Farahnaz; Campagnaro, Gustavo Daniel; Biapa Nya, Prosper C.; Mbuntcha, Hélène; Woguem, Verlaine; Womeni, Hilaire Macaire; Tapondjou, Léon Azefack; Giordani, Cristiano; Benelli, Giovanni; Hofer, Anders

2017-01-01

Essential oils are complex mixtures of volatile components produced by the plant secondary metabolism and consist mainly of monoterpenes and sesquiterpenes and, to a minor extent, of aromatic and aliphatic compounds. They are exploited in several fields such as perfumery, food, pharmaceutics, and cosmetics. Essential oils have long-standing uses in the treatment of infectious diseases and parasitosis in humans and animals. In this regard, their therapeutic potential against human African trypanosomiasis (HAT) has not been fully explored. In the present work, we have selected six medicinal and aromatic plants (Azadirachta indica, Aframomum melegueta, Aframomum daniellii, Clausena anisata, Dichrostachys cinerea, and Echinops giganteus) traditionally used in Cameroon to treat several disorders, including infections and parasitic diseases, and evaluated the activity of their essential oils against Trypanosma brucei TC221. Their selectivity was also determined with Balb/3T3 (mouse embryonic fibroblast cell line) cells as a reference. The results showed that the essential oils from A. indica, A. daniellii, and E. giganteus were the most active ones, with half maximal inhibitory concentration (IC50) values of 15.21, 7.65, and 10.50 µg/mL, respectively. These essential oils were characterized by different chemical compounds such as sesquiterpene hydrocarbons, monoterpene hydrocarbons, and oxygenated sesquiterpenes. Some of their main components were assayed as well on T. brucei TC221, and their effects were linked to those of essential oils. PMID:28684709

Method of upgrading oils containing hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline

DOEpatents

Baker, Eddie G.; Elliott, Douglas C.

1993-01-01

The present invention is a multi-stepped method of converting an oil which is produced by various biomass and coal conversion processes and contains primarily single and multiple ring hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline. The single and multiple ring hydroxyaromatic hydrocarbon compounds in a raw oil material are first deoxygenated to produce a deoxygenated oil material containing single and multiple ring aromatic compounds. Then, water is removed from the deoxygenated oil material. The next step is distillation to remove the single ring aromatic compouns as gasoline. In the third step, the multiple ring aromatics remaining in the deoxygenated oil material are cracked in the presence of hydrogen to produce a cracked oil material containing single ring aromatic compounds. Finally, the cracked oil material is then distilled to remove the single ring aromatics as gasoline.

Chemical composition and antimicrobial activity of the essential oil from the edible aromatic plant Aristolochia delavayi.

PubMed

Li, Zhi-Jian; Njateng, Guy S S; He, Wen-Jia; Zhang, Hong-Xia; Gu, Jian-Long; Chen, Shan-Na; Du, Zhi-Zhi

2013-11-01

The essential oil obtained by hydrodistillation from the aerial parts of Aristolochia delavayi Franch. (Aristolochiaceae), a unique edible aromatic plant consumed by the Nakhi (Naxi) people in Yunnan, China, was investigated using GC/MS analysis. In total, 95 components, representing more than 95% of the oil composition, were identified, and the main constituents found were (E)-dec-2-enal (52.0%), (E)-dodec-2-enal (6.8%), dodecanal (3.35%), heptanal (2.88%), and decanal (2.63%). The essential oil showed strong inhibitory activity (96% reduction) of the production of bacterial volatile sulfide compounds (VSC) by Klebsiella pneumoniae, an effect that was comparable with that of the reference compound citral (91% reduction). Moreover, the antimicrobial activity of the essential oil and the isolated major compound against eight bacterial and six fungal strains were evaluated. The essential oil showed significant antibacterial activity against Providencia stuartii and Escherichia coli, with minimal inhibitory concentrations (MIC) ranging from 3.9 to 62.5 μg/ml. The oil also showed strong inhibitory activity against the fungal strains Trichophyton ajelloi, Trichophyton terrestre, Candida glabrata, Candida guilliermondii, and Cryptococcus neoformans, with MIC values ranging from 3.9 to 31.25 μg/ml, while (E)-dec-2-enal presented a lower antifungal activity than the essential oil. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

[Estimate of the formation potential of secondary organic aerosol in Beijing summertime].

PubMed

Lü, Zi-Feng; Hao, Ji-Ming; Duan, Jing-Chun; Li, Jun-Hua

2009-04-15

Fractional aerosol coefficients (FAC) are used in conjunction with measurements of volatile organic compounds (VOC) during ozone episodes to estimate the formation potential of secondary organic aerosols (SOA) in the summertime of Beijing. The estimation is based on the actual atmospheric conditions of Beijing, and benzene and isoprene are considered as the precursors of SOA. The results show that 31 out of 70 measured VOC species are SOA precursors, and the total potential SOA formation is predicted to be 8.48 microg/m3, which accounts for 30% of fine organic particle matter. Toluene, xylene, pinene, ethylbenzene and n-undecane are the 5 largest contributors to SOA production and account for 20%, 22%, 14%, 9% and 4% of total SOA production, respectively. The anthropogenic aromatic compounds, which yield 76% of the calculated SOA, are the major source of SOA. The biogenic alkenes, alkanes and carbonyls produce 16%, 7% and 1% of SOA formation, respectively. The major components of produced SOA are expected to be aromatic compounds, aliphatic acids, carbonyls and aliphatic nitrates, which contribute to 72%, 14%, 11% and 3% of SOA mass, respectively. The SOA precursors have relatively low atmospheric concentrations and low ozone formation potential. Hence, SOA formation potential of VOC species, in addition to their atmospheric concentrations and ozone formation potential, should be considered in policy making process of VOCs control.

Evaluation of in vitro anti-proliferative and immunomodulatory activities of compounds isolated from Curcuma longa

PubMed Central

Yue, Grace G. L.; Chan, Ben C. L.; Hon, Po-Ming; Lee, Mavis Y. H.; Fung, Kwok-Pui; Leung, Ping-Chung; Lau, Clara B. S.

2010-01-01

The rhizome of Curcuma longa (CL) has been commonly used in Asia as a potential candidate for the treatment of different diseases, including inflammatory disorders and cancers. The present study evaluated the anti-proliferative activities of the isolated compounds (3 curcuminoids and 2 turmerones) from CL, using human cancer cell lines HepG2, MCF-7 and MDA-MB-231. The immunomodulatory activities of turmerones (α and aromatic) isolated from CL were also examined using human peripheral blood mononuclear cells (PBMC). Our results showed that the curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin) and α-turmerone significantly inhibited proliferation of cancer cells in dose-dependent manner. The IC50 values of these compounds in cancer cells ranged from 11.0–41.8 μg/ml. Alpha-turmerone induced MDA-MB-231 cells to undergo apoptosis, which was confirmed by annexin-V & propidium iodide staining, and DNA fragmentation assay. The caspase cascade was activated as shown by a significant decrease of procaspases-3, -8 and -9 in α-turmerone treated cells. Both α-turmerone and aromatic-turmerone showed stimulatory effects on PBMC proliferation and cytokine production. The anti-proliferative effect of α-turmerone and immunomodulatory activities of ar-turmerone were shown for the first time. The findings revealed the potential use of CL crude extract (containing curcuminoids and volatile oil including turmerones) as chemopreventive agent. PMID:20438793

Anaerobic Catabolism of Aromatic Compounds: a Genetic and Genomic View

PubMed Central

Carmona, Manuel; Zamarro, María Teresa; Blázquez, Blas; Durante-Rodríguez, Gonzalo; Juárez, Javier F.; Valderrama, J. Andrés; Barragán, María J. L.; García, José Luis; Díaz, Eduardo

2009-01-01

Summary: Aromatic compounds belong to one of the most widely distributed classes of organic compounds in nature, and a significant number of xenobiotics belong to this family of compounds. Since many habitats containing large amounts of aromatic compounds are often anoxic, the anaerobic catabolism of aromatic compounds by microorganisms becomes crucial in biogeochemical cycles and in the sustainable development of the biosphere. The mineralization of aromatic compounds by facultative or obligate anaerobic bacteria can be coupled to anaerobic respiration with a variety of electron acceptors as well as to fermentation and anoxygenic photosynthesis. Since the redox potential of the electron-accepting system dictates the degradative strategy, there is wide biochemical diversity among anaerobic aromatic degraders. However, the genetic determinants of all these processes and the mechanisms involved in their regulation are much less studied. This review focuses on the recent findings that standard molecular biology approaches together with new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, and metagenomics) have provided regarding the genetics, regulation, ecophysiology, and evolution of anaerobic aromatic degradation pathways. These studies revealed that the anaerobic catabolism of aromatic compounds is more diverse and widespread than previously thought, and the complex metabolic and stress programs associated with the use of aromatic compounds under anaerobic conditions are starting to be unraveled. Anaerobic biotransformation processes based on unprecedented enzymes and pathways with novel metabolic capabilities, as well as the design of novel regulatory circuits and catabolic networks of great biotechnological potential in synthetic biology, are now feasible to approach. PMID:19258534

Factors controlling volatile organic compounds in dwellings in Melbourne, Australia.

PubMed

Cheng, M; Galbally, I E; Molloy, S B; Selleck, P W; Keywood, M D; Lawson, S J; Powell, J C; Gillett, R W; Dunne, E

2016-04-01

This study characterized indoor volatile organic compounds (VOCs) and investigated the effects of the dwelling characteristics, building materials, occupant activities, and environmental conditions on indoor VOC concentrations in 40 dwellings located in Melbourne, Australia, in 2008 and 2009. A total of 97 VOCs were identified. Nine VOCs, n-butane, 2-methylbutane, toluene, formaldehyde, acetaldehyde, d-limonene, ethanol, 2-propanol, and acetic acid, accounted for 68% of the sum of all VOCs. The median indoor concentrations of all VOCs were greater than those measured outdoors. The occupant density was positively associated with indoor VOC concentrations via occupant activities, including respiration and combustion. Terpenes were associated with the use of household cleaning and laundry products. A petroleum-like indoor VOC signature of alkanes and aromatics was associated with the proximity of major roads. The indoor VOC concentrations were negatively correlated (P < 0.05) with ventilation. Levels of VOCs in these Australian dwellings were lower than those from previous studies in North America and Europe, probably due to a combination of an ongoing temporal decrease in indoor VOC concentrations and the leakier nature of Australian dwellings. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Characterization of inhalable particulate matter, volatile organic compounds and other chemical species measured in urban areas in New Jersey—I. Summertime episodes

NASA Astrophysics Data System (ADS)

Lioy, Paul J.; Daisey, Joan M.; Reiss, Nathan M.; Harkov, Ronald

The 1981 Summer Campaign results of the New Jersey Project on Airborne Toxic Elements and Organic Substances (ATEOS) have been examined for the accumulation of various pollutants during photochemical smog type episodes in Newark, Elizabeth and Camden, N.J. Background data were provided from a rural site in Ringwood, N.J. The interrelationships among inhalable particulate matter (IPM), particulate organic matter (POM), polycyclic aromatic hydrocarbons (PAH), SO 2-4, V, Pb, O 3, volatile organic compounds and alkylating agents are described. In addition, the prevailing synoptic meteorology was examined to characterize the episodes and define situations that significantly affected the accumulation patterns. The concentrations of PAH, toluene, benzene, V and Pb usually varied independently of the episodes indicating primary source contributions. The alkylating agent concentrations appeared to increase in association with episode periods. The results also indicated that 50-60% of the IPM mass in the urban areas was composed of the sum of SO 2-4 and POM. Between site analysis of the SO 2-4 indicated primarily a regional distribution pattern, while the POM appeared to be related to contributions from both local and regional sources.

Occupational hygiene in terms of volatile organic compounds (VOCs) and bioaerosols at two solid waste management plants in Finland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lehtinen, Jenni, E-mail: jenni.k.lehtinen@jyu.fi; Tolvanen, Outi; Nivukoski, Ulla

Highlights: ► Odorous VOCs: acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene. ► VOC concentrations did not exceed occupational exposure limit concentrations. ► 2,3-Butanedione as the health effecting compound is discussed. ► Endotoxin concentrations may cause health problems in waste treatment. - Abstract: Factors affecting occupational hygiene were measured at the solid waste transferring plant at Hyvinkää and at the optic separation plant in Hämeenlinna. Measurements consisted of volatile organic compounds (VOCs) and bioaerosols including microbes, dust and endotoxins. The most abundant compounds in both of the plants were aliphatic and aromatic hydrocarbons, esters of carboxylic acids, ketones and terpenes.more » In terms of odour generation, the most important emissions were acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene due to their low threshold odour concentrations. At the optic waste separation plant, limonene occurred at the highest concentration of all single compounds of identified VOCs. The concentration of any single volatile organic compound did not exceed the occupational exposure limit (OEL) concentration. However, 2,3-butanedione as a health risk compound is discussed based on recent scientific findings linking it to lung disease. Microbe and dust concentrations were low at the waste transferring plant. Only endotoxin concentrations may cause health problems; the average concentration inside the plant was 425 EU/m{sup 3} which clearly exceeded the threshold value of 90 EU/m{sup 3}. In the wheel loader cabin the endotoxin concentrations were below 1 EU/m{sup 3}. High microbial and endotoxin concentrations were measured in the processing hall at the optic waste separation plant. The average concentration of endotoxins was found to be 10,980 EU/m{sup 3}, a concentration which may cause health risks. Concentrations of viable fungi were quite high in few measurements in the control room. The most problematic factor was endotoxins whose average measured concentrations was 4853 EU/m{sup 3}.« less

Impact of fruit texture on the release and perception of aroma compounds during in vivo consumption using fresh and processed mango fruits.

PubMed

Bonneau, Adeline; Boulanger, Renaud; Lebrun, Marc; Maraval, Isabelle; Valette, Jérémy; Guichard, Élisabeth; Gunata, Ziya

2018-01-15

Two fresh (fresh cubic pieces, fresh puree) and two dried (dried cubic pieces, dried powder) products were prepared from a homogenous mango fruit batch to obtain four samples differing in texture. The aromatic profiles were determined by SAFE extraction technique and GC-MS analysis. VOCs released during consumption were trapped by a retronasal aroma-trapping device (RATD) and analysed by GC-MS. Twenty-one terpenes and one ester were identified from the exhaled nose-space. They were amongst the major mango volatile compounds, 10 of which were already reported as being potential key flavour compounds in mango. The in vivo release of aroma compounds was affected by the matrix texture. The intact samples (fresh and dried cubic pieces) released significantly more aroma compounds than disintegrated samples (fresh puree, dried powder). The sensory descriptive analysis findings were in close agreement with the in vivo aroma release data regarding fresh products, in contrast to the dried products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biotechnological production of aromatic compounds of the extended shikimate pathway from renewable biomass.

PubMed

Lee, Jin-Ho; Wendisch, Volker F

2017-09-10

Aromatic chemicals that contain an unsaturated ring with alternating double and single bonds find numerous applications in a wide range of industries, e.g. paper and dye manufacture, as fuel additives, electrical insulation, resins, pharmaceuticals, agrochemicals, in food, feed and cosmetics. Their chemical production is based on petroleum (BTX; benzene, toluene, and xylene), but they can also be obtained from plants by extraction. Due to petroleum depletion, health compliance, or environmental issues such as global warming, the biotechnological production of aromatics from renewable biomass came more and more into focus. Lignin, a complex polymeric aromatic molecule itself, is a natural source of aromatic compounds. Many microorganisms are able to catabolize a plethora of aromatic compounds and interception of these pathways may lead to the biotechnological production of value-added aromatic compounds which will be discussed for Corynebacterium glutamicum. Biosynthesis of aromatic amino acids not only gives rise to l-tryptophan, L-tyrosine and l-phenylalanine, but also to aromatic intermediates such as dehydroshikimate or chorismate from which value-added aromatic compounds can be derived. In this review, we will summarize recent strategies for the biotechnological production of aromatic and related compounds from renewable biomass by Escherichia coli, Pseudomonas putida, C. glutamicum and Saccharomyces cerevisiae. In particular, we will focus on metabolic engineering of the extended shikimate pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

PERFLUORINATED AROMATIC COMPOUND

DTIC Science & Technology

octafluorobiphenyl, and perfluoroaliphatic aldehydes. Synthetic routes to perfluoro cyclohexyls via reactions of phenyl and pentafluorphenyl lithium with...other perfluorinated aromatic compounds were employed in the synthesis of perfluorinated aromatic model compounds and polymers. The hydrogenic analogues...hydrazides, and imides. Synthetic routes to perfluoro aralkyl compounds are being investigated. Starting materials are tetrafluorobenzene

Modeling the formation and properties of traditional and non-traditional secondary organic aerosol: problem formulation and application to aircraft exhaust

NASA Astrophysics Data System (ADS)

Jathar, S. H.; Miracolo, M. A.; Presto, A. A.; Adams, P. J.; Robinson, A. L.

2012-04-01

We present a methodology to model secondary organic aerosol (SOA) formation from the photo-oxidation of low-volatility organics (semi-volatile and intermediate volatility organic compounds). The model is parameterized and tested using SOA data collected during two field campaigns that characterized the atmospheric evolution of dilute gas-turbine engine emissions using a smog chamber. Photo-oxidation formed a significant amount of SOA, much of which cannot be explained based on the emissions of traditional, speciated precursors; we refer to this as non-traditional SOA (NT-SOA). The NT-SOA can be explained by emissions of low-volatility organic vapors measured using sorbents. Since these vapors could not be speciated, we employ a volatility-based approach to model NT-SOA formation. We show that the method proposed by Robinson et al. (2007) is unable to explain the timing of NT-SOA formation because it assumes a very modest reduction in volatility of the precursors with every oxidation reaction. In contrast, a Hybrid method, similar to models of traditional SOA formation, assumes a larger reduction in volatility with each oxidation step and results in a better reproduction of NT-SOA formation. The NT-SOA yields estimated for the low-volatility organic vapor emissions are similar to literature data for large n-alkanes and other low-volatility organics. The yields vary with fuel composition (JP8 versus Fischer-Tropsch) and engine load (idle versus non-idle). These differences are consistent with the expected contribution of high (aromatics and n-alkanes) and low (branched alkanes and oxygenated species) SOA forming species to the exhaust.

Seasonal fate and gas/particle partitioning of semi-volatile organic compounds in indoor and outdoor air

NASA Astrophysics Data System (ADS)

Moreau-Guigon, Elodie; Alliot, Fabrice; Gaspéri, Johnny; Blanchard, Martine; Teil, Marie-Jeanne; Mandin, Corinne; Chevreuil, Marc

2016-12-01

Fifty-eight semi-volatile organic compounds (SVOCs) were investigated simultaneously in three indoor (apartment, nursery and office building) and one outdoor environment in the centre of Paris (France). All of these compounds except tetrabromobisphenol A were quantified in the gaseous and particulate phases in all three environments, and at a frequency of 100% for the predominant compounds of each SVOC class. Phthalic acid esters (PAEs) were the most abundant group (di-iso-butyl phthalate: 29-661 ng m-3, diethyl phthalate: 15-542 ng m-3), followed by 4-nonylphenol (1.4-81 ng m-3), parabens (methylparaben: 0.03-2.5 ng m-3), hexachlorobenzene (HCB) (0.002-0.26 ng m-3) and pentachlorobenzene (PeCB) (0.001-0.23 ng m-3). Polycyclic aromatic hydrocarbons (as ∑8PAHs) ranged from 0.17 to 5.40 ng m-3, polychlorinated biphenyls (as ∑7PCBi) from 0.06 to 4.70 ng.m3 and polybromodiphenyl ethers (as ∑8PBDEs) from 0.002 to 0.40 ng m-3. For most pollutants, significantly higher concentrations were observed in the nursery compared to the apartment and office. Overall, the indoor air concentrations were up to ten times higher than outdoor air concentrations. Seasonal variations were observed for PAEs, PCBs and PAHs. SVOCs were predominantly identified in the gaseous phase (>90%), except for some high-molecular-weight PAEs, PAHs and PCBs.

Emissions databases for polycyclic aromatic compounds in the Canadian Athabasca oil sands region - development using current knowledge and evaluation with passive sampling and air dispersion modelling data

NASA Astrophysics Data System (ADS)

Qiu, Xin; Cheng, Irene; Yang, Fuquan; Horb, Erin; Zhang, Leiming; Harner, Tom

2018-03-01

Two speciated and spatially resolved emissions databases for polycyclic aromatic compounds (PACs) in the Athabasca oil sands region (AOSR) were developed. The first database was derived from volatile organic compound (VOC) emissions data provided by the Cumulative Environmental Management Association (CEMA) and the second database was derived from additional data collected within the Joint Canada-Alberta Oil Sands Monitoring (JOSM) program. CALPUFF modelling results for atmospheric polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and dibenzothiophenes (DBTs), obtained using each of the emissions databases, are presented and compared with measurements from a passive air monitoring network. The JOSM-derived emissions resulted in better model-measurement agreement in the total PAH concentrations and for most PAH species concentrations compared to results using CEMA-derived emissions. At local sites near oil sands mines, the percent error of the model compared to observations decreased from 30 % using the CEMA-derived emissions to 17 % using the JOSM-derived emissions. The improvement at local sites was likely attributed to the inclusion of updated tailings pond emissions estimated from JOSM activities. In either the CEMA-derived or JOSM-derived emissions scenario, the model underestimated PAH concentrations by a factor of 3 at remote locations. Potential reasons for the disagreement include forest fire emissions, re-emissions of previously deposited PAHs, and long-range transport not considered in the model. Alkylated PAH and DBT concentrations were also significantly underestimated. The CALPUFF model is expected to predict higher concentrations because of the limited chemistry and deposition modelling. Thus the model underestimation of PACs is likely due to gaps in the emissions database for these compounds and uncertainties in the methodology for estimating the emissions. Future work is required that focuses on improving the PAC emissions estimation and speciation methodologies and reducing the uncertainties in VOC emissions which are subsequently used in PAC emissions estimation.

Combined effects of nutrients and temperature on the production of fermentative aromas by Saccharomyces cerevisiae during wine fermentation.

PubMed

Rollero, Stéphanie; Bloem, Audrey; Camarasa, Carole; Sanchez, Isabelle; Ortiz-Julien, Anne; Sablayrolles, Jean-Marie; Dequin, Sylvie; Mouret, Jean-Roch

2015-03-01

Volatile compounds produced by yeast during fermentation greatly influence the organoleptic qualities of wine. We developed a model to predict the combined effects of initial nitrogen and phytosterol content and fermentation temperature on the production of volatile compounds. We used a Box-Behnken design and response surface modeling to study the response of Lalvin EC1118® to these environmental conditions. Initial nitrogen content had the greatest influence on most compounds; however, there were differences in the value of fermentation parameters required for the maximal production of the various compounds. Fermentation parameters affected differently the production of isobutanol and isoamyl alcohol, although their synthesis involve the same enzymes and intermediate. We found differences in regulation of the synthesis of acetates of higher alcohols and ethyl esters, suggesting that fatty acid availability is the main factor influencing the synthesis of ethyl esters whereas the production of acetates depends on the activity of alcohol acetyltransferases. We also evaluated the effect of temperature on the total production of three esters by determining gas-liquid balances. Evaporation largely accounted for the effect of temperature on the accumulation of esters in liquid. Nonetheless, the metabolism of isoamyl acetate and ethyl octanoate was significantly affected by this parameter. We extended this study to other strains. Environmental parameters had a similar effect on aroma production in most strains. Nevertheless, the regulation of the synthesis of fermentative aromas was atypical in two strains: Lalvin K1M® and Affinity™ ECA5, which produces a high amount of aromatic compounds and was obtained by experimental evolution.

Tracing the link between plant volatile organic compound emissions and CO2 fluxes and by stable isotopes

NASA Astrophysics Data System (ADS)

Werner, Christiane; Wegener, Frederik; Jardine, Kolby

2015-04-01

The vegetation exerts a large influence on the atmosphere through the emission of volatile organic compounds (VOCs) and the emission and uptake of the greenhouse gas CO2. Despite the enormous importance, processes controlling plant carbon allocation into primary and secondary metabolism, such as photosynthetic carbon uptake, respiratory CO2 emission and VOC synthesis, remains unclear. Moreover, vegetation-atmosphere CO2 exchange is associated with a large isotopic imprint due to photosynthetic carbon isotope discrimination and 13C-fractionation during respiratory CO2 release1. The latter has been proposed to be related to carbon partitioning in the metabolic branching points of the respiratory pathways and secondary metabolism, which are linked via a number of interfaces including the central metabolite pyruvate. Notably, it is a known substrate in a large array of secondary pathways leading to the biosynthesis of many volatile organic compounds (VOCs), such as volatile isoprenoids, oxygenated VOCs, aromatics, fatty acid oxidation products, which can be emitted by plants. Here we investigate the linkage between VOC emissions, CO2 fluxes and associated isotope effects based on simultaneous real-time measurements of stable carbon isotope composition of branch respired CO2 (CRDS) and VOC fluxes (PTR-MS). We utilized positionally specific 13C-labeled pyruvate branch feeding experiments in the mediterranean shrub (Halimium halimifolium) to trace the partitioning of C1, C2, and C3 carbon atoms of pyruvate into VOCs versus CO2 emissions in the light and in the dark. In the light, we found high emission rates of a large array of VOC including volatile isoprenoids, oxygenated VOCs, green leaf volatiles, aromatics, sulfides, and nitrogen containing VOCs. These observations suggest that in the light, H. halimifolium dedicates a high carbon flux through secondary biosynthetic pathways including the pyruvate dehydrogenase bypass, mevalonic acid, MEP/DOXP, shikimic acid, and fatty acid pathways. Moreover, we found that high VOC emissions were closely related to 13CO2 decarboxylation from pyruvate-1-13C in the light, while mitochondrial respiration mas markedly down-regulated. Moreover, we found that in the dark, VOC emissions dramatically declined while respiration was stimulated with 13CO2 emissions under pyruvate-1-13C exceeding those under pyruvate-2-13C and pyruvate-2,3-13C during light-dark transitions. Our observations suggest VOC emissions are associated with significant pyruvate C1 decarboxylation. Moreover, the data suggests that light fundamentally controls the partitioning of assimilated carbon in leaves by regulating the competition for pyruvate between secondary biosynthetic reactions (e.g. VOC production) and mitochondrial respiration. Our investigation provides novel tool to better understand the mechanistic links between primary and secondary carbon metabolism in plants with important implications for a better understanding biosphere-atmosphere exchange of CO2 and VOCs. References 1. Werner C. & Gessler A. (2011) Diel variations in the carbon isotope composition of respired CO2 and associated carbon sources: a review of dynamics and mechanisms. Biogeosciences 8, 2437-2459 2. Jardine K, Wegener F, Abrell L, vonHaren J, Werner C (2014) Phytogenic biosynthesis and emission of methyl acetate. PCE 37, 414-424.

Public health assessment for Alcoa (Point Comfort)/Lavaca Bay, Point Comfort, Calhoun County, Texas, Region 6. Cerclis No. TXD008123168. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-08-24

The ALCOA (Point Comfort)/Lavaco Bay National Priorities List (NPL) site is in Calhoun County, Texas, approximately 1.5 miles south of Point Comfort and four miles northeast of Port Lavaca. Fish sampling data indicate that levels of mercury in fish are elevated. Mercury has been detected throughout the site in surface soil, shallow groundwater, air, bay sediments, fish and crabs. Other contaminants, including volatile organic compounds (VOCs) and lead, have been detected in shallow groundwater. Polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) have been detected in a limited number of sediment, fish, and oyster samples.

Groundwater quality from private domestic water-supply wells in the vicinity of petroleum production in southwestern Indiana

USGS Publications Warehouse

Risch, Martin R.; Silcox, Cheryl A.

2016-06-02

The U.S. Geological Survey provided technical support to the Agency for Toxic Substances and Disease Registry for site selection and sample collection and analysis in a 2012 investigation of groundwater quality from 29 private domestic water-supply wells in the vicinity of petroleum production in southwestern Indiana. Petroleum hydrocarbons, oil and grease, aromatic volatile organic compounds, methane concentrations greater than 8,800 micrograms per liter, chloride concentrations greater than 250 milligrams per liter, and gross alpha radioactivity greater than 15 picocuries per liter were reported in the analysis of groundwater samples from 11 wells.

Water-quality data of stormwater runoff from Davenport, Iowa, 1992 and 1994

USGS Publications Warehouse

Schaap, B.D.; Einhellig, R.F.

1996-01-01

During 1992 and 1994, stormwater runoff in Davenport, Iowa, was sampled from the following land use types: agricultural and vacant, residential, commercial, parks and wooded areas, and industrial. Grab samples collected within the first hour of the runoff event were analyzed for many constituents including volatile organic compounds. Flow-weighted composite samples, composed from discrete samples collected at 15-minute intervals during the first three hours of the event or until discharge returned to pre-event levels, also were analyzed for many constituents including major ions, nitrogen, phosphorus, metals, total organic carbon, acid/base-neutral organics, organochlorine pesticides, and polycyclic aromatic hydrocarbons.

An Efficient Extraction Method for Fragrant Volatiles from Jasminum sambac (L.) Ait.

PubMed

Ye, Qiuping; Jin, Xinyi; Zhu, Xinliang; Lin, Tongxiang; Hao, Zhilong; Yang, Qian

2015-01-01

The sweet smell of aroma of Jasminum sambac (L.) Ait. is releasing while the flowers are blooming. Although components of volatile oil have been extensively studied, there are problematic issues, such as low efficiency of yield, flavour distortion. Here, the subcritical fluid extraction (SFE) was performed to extract fragrant volatiles from activated carbon that had absorbed the aroma of jasmine flowers. This novel method could effectively obtain main aromatic compounds with quality significantly better than solvent extraction (SE). Based on the analysis data with response surface methodology (RSM), we optimized the extraction conditions which consisted of a temperature of 44°C, a solvent-to-material ratio of 3.5:1, and an extraction time of 53 min. Under these conditions, the extraction yield was 4.91%. Furthermore, the key jasmine essence oil components, benzyl acetate and linalool, increase 7 fold and 2 fold respectively which lead to strong typical smell of the jasmine oil. The new method can reduce spicy components which lead to the essential oils smelling sweeter. Thus, the quality of the jasmine essence oil was dramatically improved and yields based on the key component increased dramatically. Our results provide a new effective technique for extracting fragrant volatiles from jasmine flowers.

Zeolite-loaded poly(dimethylsiloxane) hybrid films for highly efficient thin-film microextraction of organic volatiles in water.

PubMed

Wang, Tao; Ansai, Toshihiro; Lee, Seung-Woo

2017-01-15

ZSM-5 zeolite-loaded poly(dimethylsiloxane) (PDMS) hybrid thin films were demonstrated for efficient thin-film microextraction (TFME) coupled with gas chromatography-mass spectrometry for analyzing organic volatiles in water. The extraction efficiency for a series of aliphatic alcohols and two aromatic compounds was significantly improved owing to the presence of ZSM-5 zeolites. The extraction efficiency of the hybrid films was increased in proportion to the content of ZSM-5 in the PDMS film, with 20wt% of ZSM-5 showing the best results. The 20wt% ZSM-5/PDMS hybrid film exhibited higher volatile organic content extraction compared with the single-component PDMS film or PDMS hybrid films containing other types of zeolite (e.g., SAPO-34). Limits of detection and limits of quantitation for individual analytes were in the range of 0.0034-0.049ppb and of 0.010-0.15 ppb, respectively. The effects of experimental parameters such as extraction time and temperature were optimized, and the molecular dispersion of the zeolites in/on the hybrid film matrix was confirmed with scanning electron microscopy and atomic force microscopy. Furthermore, the optimized hybrid film was preliminarily tested for the analysis of organic volatiles contained in commercially available soft drinks. Copyright © 2016 Elsevier B.V. All rights reserved.

Real-time and online screening method for materials emitting volatile organic compounds

NASA Astrophysics Data System (ADS)

Kim, Changhyuk; Sul, Yong Tae; Pui, David Y. H.

2016-09-01

In the semiconductor industry, volatile organic compounds (VOCs) in the cleanroom air work as airborne molecular contamination, which reduce the production yield of semiconductor chips by forming nanoparticles and haze on silicon wafers and photomasks under ultraviolet irradiation during photolithography processes. Even though VOCs in outdoor air are removed by gas filters, VOCs can be emitted from many kinds of materials used in cleanrooms, such as organic solvents and construction materials (e.g., adhesives, flame retardants and sealants), threatening the production of semiconductors. Therefore, finding new replacements that emit lower VOCs is now essential in the semiconductor industry. In this study, we developed a real-time and online method to screen materials for developing the replacements by converting VOCs into nanoparticles under soft X-ray irradiation. This screening method was applied to measure VOCs emitted from different kinds of organic solvents and adhesives. Our results showed good repeatability and high sensitivity for VOCs, which come from aromatic compounds, some alcohols and all tested adhesives (Super glue and cleanroom-use adhesives). In addition, the overall trend of measured VOCs from cleanroom-use adhesives was well matched with those measured by a commercial thermal desorption-gas chromatography-mass spectrometry, which is a widely used off-line method for analyzing VOCs. Based on the results, this screening method can help accelerate the developing process for reducing VOCs in cleanrooms.

Volatile organic compounds speciation and their influence on ozone formation potential in an industrialized urban area in Brazil.

PubMed

Galvão, Elson Silva; Santos, Jane Meri; Reis Junior, Neyval Costa; Stuetz, Richard Michael

2016-09-01

Speciation and the influence on the ozone formation potential (OFP) from volatile organic compounds (VOCs) have been studied between February June 2013 in Vitória, ES, Brazil. Passive samplers were installed at three air-quality monitoring stations and a total of 96 samplings were collected. A total of 78 VOCs were characterized by gas chromatograph-mass spectrometer. The predominant group was organic acids, followed by alcohols and substituted aromatics and 14 precursor species were quantified. An analysis correlating concentrations with wind direction was conducted to identify possible sources. The OFP was calculated applying the scale of maximum incremental reactivity proposed by Carter.[ 23 ] Ozone precursors with the greatest OFP such as undecane, toluene, ethylbenzene and m, p-xylene compounds were the most abundant with means of 0.855, 0.365, 0.259 and 0.289 µg m(-3), respectively. The benzene, toluene, ethylbenzene and xylene (BTEX) group was found below the limits considered harmful to the health of the population living in Vitória. The OFP calculated for the precursors group was 22.55 µg m(-3) for the rainy season and 32.11 µg m(-3) for the dry season. The VOC/NOx ratio in Vitória is approximately 1.71, indicating that the region has a VOC-limiting condition for the production of ozone.

Development of genetically engineered bacteria for production of selected aromatic compounds

DOEpatents

Ward, Thomas E.; Watkins, Carolyn S.; Bulmer, Deborah K.; Johnson, Bruce F.; Amaratunga, Mohan

2001-01-01

The cloning and expression of genes in the common aromatic pathway of E. coli are described. A compound for which chorismate, the final product of the common aromatic pathway, is an anabolic intermediate can be produced by cloning and expressing selected genes of the common aromatic pathway and the genes coding for enzymes necessary to convert chorismate to the selected compound. Plasmids carrying selected genes of the common aromatic pathway are also described.

Polydimethylsiloxane-air partition ratios for semi-volatile organic compounds by GC-based measurement and COSMO-RS estimation: Rapid measurements and accurate modelling.

PubMed

Okeme, Joseph O; Parnis, J Mark; Poole, Justen; Diamond, Miriam L; Jantunen, Liisa M

2016-08-01

Polydimethylsiloxane (PDMS) shows promise for use as a passive air sampler (PAS) for semi-volatile organic compounds (SVOCs). To use PDMS as a PAS, knowledge of its chemical-specific partitioning behaviour and time to equilibrium is needed. Here we report on the effectiveness of two approaches for estimating the partitioning properties of polydimethylsiloxane (PDMS), values of PDMS-to-air partition ratios or coefficients (KPDMS-Air), and time to equilibrium of a range of SVOCs. Measured values of KPDMS-Air, Exp' at 25 °C obtained using the gas chromatography retention method (GC-RT) were compared with estimates from a poly-parameter free energy relationship (pp-FLER) and a COSMO-RS oligomer-based model. Target SVOCs included novel flame retardants (NFRs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), organophosphate flame retardants (OPFRs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Significant positive relationships were found between log KPDMS-Air, Exp' and estimates made using the pp-FLER model (log KPDMS-Air, pp-LFER) and the COSMOtherm program (log KPDMS-Air, COSMOtherm). The discrepancy and bias between measured and predicted values were much higher for COSMO-RS than the pp-LFER model, indicating the anticipated better performance of the pp-LFER model than COSMO-RS. Calculations made using measured KPDMS-Air, Exp' values show that a PDMS PAS of 0.1 cm thickness will reach 25% of its equilibrium capacity in ∼1 day for alpha-hexachlorocyclohexane (α-HCH) to ∼ 500 years for tris (4-tert-butylphenyl) phosphate (TTBPP), which brackets the volatility range of all compounds tested. The results presented show the utility of GC-RT method for rapid and precise measurements of KPDMS-Air. Copyright © 2016. Published by Elsevier Ltd.

Determination of volatile organic hydrocarbons in water samples by solid-phase dynamic extraction.

PubMed

Jochmann, Maik A; Yuan, Xue; Schmidt, Torsten C

2007-03-01

In the present study a headspace solid-phase dynamic extraction method coupled to gas chromatography-mass spectrometry (HS-SPDE-GC/MS) for the trace determination of volatile halogenated hydrocarbons and benzene from groundwater samples was developed and evaluated. As target compounds, benzene as well as 11 chlorinated and brominated hydrocarbons (vinyl chloride, dichloromethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, bromoform) of environmental and toxicological concern were included in this study. The analytes were extracted using a SPDE needle device, coated with a poly(dimethylsiloxane) with 10% embedded activated carbon phase (50-microm film thickness and 56-mm film length) and were analyzed by GC/MS in full-scan mode. Parameters that affect the extraction yield such as extraction and desorption temperature, salting-out, extraction and desorption flow rate, extraction volume and desorption volume, the number of extraction cycles, and the pre-desorption time have been evaluated and optimized. The linearity of the HS-SPDE-GC/MS method was established over several orders of magnitude. Method detection limits (MDLs) for the compounds investigated ranged between 12 ng/L for cis-dichloroethylene and trans-dichloroethylene and 870 ng/L for vinyl chloride. The method was thoroughly validated, and the precision at two concentration levels (0.1 mg/L and a concentration 5 times above the MDL) was between 3.1 and 16% for the analytes investigated. SPDE provides high sensitivity, short sample preparation and extraction times and a high sample throughput because of full automation. Finally, the applicability to real environmental samples is shown exemplarily for various groundwater samples from a former waste-oil recycling facility. Groundwater from the site showed a complex contamination with chlorinated volatile organic compounds and aromatic hydrocarbons.

Volatile Organic Compounds Induced by Herbivory of the Soybean Looper Chrysodeixis includens in Transgenic Glyphosate-Resistant Soybean and the Behavioral Effect on the Parasitoid, Meteorus rubens.

PubMed

Strapasson, Priscila; Pinto-Zevallos, Delia M; Da Silva Gomes, Sandra M; Zarbin, Paulo H G

2016-08-01

Transgenic soybean plants (RR) engineered to express resistance to glyphosate harbor a variant of the enzyme EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) involved in the shikimic acid pathway, the biosynthetic route of three aromatic amino acids: phenylalanine, tyrosine, and tryptophan. The insertion of the variant enzyme CP4 EPSPS confers resistance to glyphosate. During the process of genetic engineering, unintended secondary effects are likely to occur. In the present study, we quantified volatile organic compounds (VOCs) emitted constitutively or induced in response to herbivory by the soybean looper Chrysodeixis includens in transgenic soybean and its isogenic (untransformed) line. Since herbivore-induced plant volatiles (HIPVs) are known to play a role in the recruitment of natural enemies, we assessed whether changes in VOC profiles alter the foraging behavior of the generalist endoparasitic larval parasitoid, Meteorus rubens in the transgenic line. Additionally, we assessed whether there was a difference in plant quality by measuring the weight gain of the soybean looper. In response to herbivory, several VOCs were induced in both the conventional and the transgenic line; however, larger quantities of a few compounds were emitted by transgenic plants. Meteorus rubens females were able to discriminate between the odors of undamaged and C. includens-damaged plants in both lines, but preferred the odors emitted by herbivore-damaged transgenic plants over those emitted by herbivore-damaged conventional soybean plants. No differences were observed in the weight gain of the soybean looper. Our results suggest that VOC-mediated tritrophic interactions in this model system are not negatively affected. However, as the preference of the wasps shifted towards damaged transgenic plants, the results also suggest that genetic modification affects that tritrophic interactions in multiple ways in this model system.

Volatile organic compounds obtained by in vitro callus cultivation of Plectranthus ornatus Codd. (Lamiaceae).

PubMed

Passinho-Soares, Helna C; Meira, Paloma R; David, Juceni P; Mesquita, Paulo R R; do Vale, Ademir E; de M Rodrigues, Frederico; de P Pereira, Pedro A; de Santana, José Raniere F; de Oliveira, Fabio S; de Andrade, Jailson B; David, Jorge M

2013-08-26

Plectranthus spp (Lamiaceae) are plants of economic importance because they are sources of aromatic essential oils and are also cultivated and several species of this genus are used as folk medicines. This paper describes the effects of different concentrations of the 2,4-dichlorophenoxyacetic acid (2,4-D) and 1-naphthaleneacetic acid (NAA) on the induction of callus from nodal segments of Plectranthus ornatus Codd and in the production of volatile organic compounds (monoterpenes and sesquiterpenes). The 20 and 40 day calli were subjected to solid phase micro extraction (HS-SPME) and submitted to GCMS analysis. Variations in VOCs between the samples were observed and, a direct relationship was observed between of the major constituent detected (α-terpinyl acetate) and the monoterpenes α-thujene, α-pinene, β-pinene, camphene, sabinene and α-limonene that were present in the volatile fractions. Besides α-terpinyl acetate, isobornyl acetate and α-limonene were also major constituents. Variations were observed in VOCs in the analyzed periods. The best cultivation media for the production of VOCs was found to be MS0 (control). Moderate success was achieved by treatment with 2.68 µM and 5:37 µM NAA (Group 2). With 2,4-D (9.0 µM), only the presence of α-terpinyl acetate and isocumene were detected and, with 2.26 µM of 2,4-D was produced mainly α-terpinyl acetate, α-thujene and β-caryophyllene (16.2%). The VOC profiles present in P. ornatus were interpreted using PCA and HCA. The results permitted us to determine the best cultivation media for VOC production and, the PCA and HCA analysis allowed us to recognize four groups among the different treatments from the compounds identified in this set of treatments.

Observations of volatile organic compounds over the North Atlantic Ocean: relationships to dominant cyanobacterial populations.

NASA Astrophysics Data System (ADS)

Swarthout, R.; Rossell, R.; Sive, B. C.; Zhou, Y.; Reddy, C. M.; Valentine, D. L.; Cox, D.

2017-12-01

Marine cyanobacteria are abundant primary producers that can have a major influence on the oceanic biogeochemical cycles. In particular, the prominent cyanobacterial genera Prochlorococcus, Synechococcus, and Trichodesmium can impact the air-sea flux of volatile organic compounds (VOCs) including reactive compounds, such as isoprene, that control the oxidative capacity of the atmosphere and climate-relevant compounds, such as dimethyl sulfide. These groups of cyanobacteria have been estimated to increase in abundance by up to 29% by the end of the century as a result of rising sea surface temperatures and dissolved carbon dioxide concentrations. Given their current and predicted future abundance, understanding the role of different cyanobacterial populations on VOC emissions from the ocean is critical in understanding the future oxidative capacity of the remote atmosphere and climate feedback cycles. During the May 2017 Phosphorus, Hydrocarbons, and Transcriptomics cruise aboard the R/V Neil Armstrong, 160 whole air canister samples were collected along a transect through the North Atlantic from Woods Hole, MA to Bermuda and back with 24-hour stops at nine stations encompassing different nutrient regimes and cyanobacterial populations. At each station, a diurnal time series of samples was collected and higher frequency sampling was conducted during transits of the north wall. Canister samples were analyzed on a five-detector gas chromatography system for over 80 individual VOCs including biogenics, aromatics, chlorinated and brominated compounds, and sulfur containing compounds. Trends in reactive and climate-relevant VOCs will be discussed as a function of the predominant cyanobacterial populations at each sample location. These data provide increased information on the spatial and diurnal variability of trace gases associated with these globally important photosynthetic cyanobacteria.

Indoor air quality in hair salons: Screening of volatile organic compounds and indicators based on health risk assessment

NASA Astrophysics Data System (ADS)

de Gennaro, Gianluigi; de Gennaro, Lucrezia; Mazzone, Antonio; Porcelli, Francesca; Tutino, Maria

2014-02-01

Volatile organic compounds (VOCs) are common ingredients in cosmetic products which can impact human health. This study monitored 12 hairdressing salons in order to assess the individual exposure of the people working in or frequenting these environments as well as identify the main products or activities responsible for the presence of these compounds. In each site halogenated, oxygenated, aliphatic and aromatic compounds were monitored during the work week with diffusive samplers suitable for thermal desorption and analysed using GC-MS. The study of indoor-outdoor concentration ratios and a knowledge of the composition of most of the products, whether ecological or traditional, used in the hair salons verified the presence of compounds linked to hairdressing activities. In particular, compounds widely used in products for hair care as spray lacquer and foam (butane), shampoo, balms, hair masks and oils (camphene, camphor, limonene, eucalyptol, alpha pinene, 1-methoxy-2-propanol, n-butanol and menthol), and hair dye (benzyl alcohol, isopropanol, limonene, hexane and methyl ethyl ketone) were found at much higher levels inside rather than outside the salons (mean I/O > 10). The importance of this finding is linked to the potential health hazards of some of the VOCs detected. Integrated indicators of health risk were proposed in this study to assess the criticality level and rank the investigated environments accordingly. The results of this study indicate that the level of VOC concentrations was most affected by the type of products used while the size of the environment, the efficiency of air exchange and the number of customers had less impact on those levels.

Effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds using a modified QSAR model.

PubMed

Lim, Seung Joo; Fox, Peter

2014-02-01

The effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds were investigated using a modified half life equation. The potential future pharmaceutical compounds investigated were approximately 2000 pharmaceutical drugs currently undergoing the United States Food and Drug Administration (US FDA) testing. EPI Suite (BIOWIN) model estimates the fates of compounds based on the biodegradability under aerobic conditions. While BIOWIN considered the biodegradability of a compound only, the half life equation used in this study was modified by biodegradability, sorption and cometabolic oxidation. It was possible that the potential future pharmaceutical compounds were more accurately estimated using the modified half life equation. The modified half life equation considered sorption and cometabolic oxidation of halogenated aromatic/aliphatics and nitrogen(N)-heterocyclic aromatics in the sub-surface, while EPI Suite (BIOWIN) did not. Halogenated aliphatics in chemicals were more persistent than halogenated aromatics in the sub-surface. In addition, in the sub-surface environment, the fates of organic chemicals were much more affected by halogenation in chemicals than by nitrogen(N)-heterocyclic aromatics. © 2013.

Insight into unresolved complex mixtures of aromatic hydrocarbons in heavy oil via two-dimensional gas chromatography coupled with time-of-flight mass spectrometry analysis.

PubMed

Weng, Na; Wan, Shan; Wang, Huitong; Zhang, Shuichang; Zhu, Guangyou; Liu, Jingfu; Cai, Di; Yang, Yunxu

2015-06-12

The aromatic hydrocarbon fractions of five crude oils representing a natural sequence of increasing degree of biodegradation from the Liaohe Basin, NE, China, were analyzed using conventional gas chromatography-mass spectrometry (GC-MS) and comprehensive two-dimensional gas chromatography (GC×GC). Because of the limited peak capability and low resolution, compounds in the aromatic fraction of a heavily biodegraded crude oil that were analyzed by GC-MS appeared as unresolved complex mixtures (UCMs) or GC "humps". They could be separated based on their polarity by GC×GC. UCMs are composed mainly of aromatic biomarkers and aromatic hydrocarbons with branched alkanes or cycloalkanes substituents. The quantitative results achieved by GC×GC-FID were shown that monoaromatic hydrocarbons account for the largest number and mass of UCMs in the aromatic hydrocarbon fraction of heavily biodegraded crude oil, at 45% by mass. The number and mass of diaromatic hydrocarbons ranks second at 33% by mass, followed by the aromatic biomarker compounds, triaromatic, tetraaromatic, and pentaaromatic hydrocarbons, that account for 10%, 6%, 1.5%, and 0.01% of all aromatic compounds by mass, respectively. In the heavily biodegraded oil, compounds with monocyclic cycloalkane substituents account for the largest proportion of mono- and diaromatic hydrocarbons, respectively. The C4-substituted compounds account for the largest proportion of naphthalenes and the C3-substituted compounds account for the largest proportion of phenanthrenes, which is very different from non-biodegraded, slightly biodegraded, and moderately biodegraded crude oil. It is inferred that compounds of monoaromatic, diaromatic and triaromatic hydrocarbons are affected by biodegradation, that compounds with C1-, C2-substituents are affected by the increase in degree of biodegradation, and that their relative content decreased, whereas compounds with C3-substituents or more were affected slightly or unaffected, and their relative content also increased. The varying regularity of relative content of substituted compounds may be used to reflect the degree of degradation of heavy oil. Moreover, biomarkers for the aromatic hydrocarbons of heavily biodegraded crude oil are mainly aromatic steranes, aromatic secohopanes, aromatic pentacyclotriterpanes, and benzohopanes. According to resultant data, aromatic secohopanes could be used as a specific marker because of their relatively high concentration. This aromatic compound analysis of a series of biodegraded crude oil is useful for future research on the quantitative characterization of the degree of biodegradation of heavy oil, unconventional oil maturity evaluation, oil source correlation, depositional environment, and any other geochemical problems. Copyright © 2015 Elsevier B.V. All rights reserved.

[Application characteristics and situation analysis of volatile oils in database of Chinese patent medicine].

PubMed

Wang, Sai-Jun; Wu, Zhen-Feng; Yang, Ming; Wang, Ya-Qi; Hu, Peng-Yi; Jie, Xiao-Lu; Han, Fei; Wang, Fang

2014-09-01

Aromatic traditional Chinese medicines have a long history in China, with wide varieties. Volatile oils are active ingredients extracted from aromatic herbal medicines, which usually contain tens or hundreds of ingredients, with many biological activities. Therefore, volatile oils are often used in combined prescriptions and made into various efficient preparations for oral administration or external use. Based on the sources from the database of Newly Edited National Chinese Traditional Patent Medicines (the second edition), the author selected 266 Chinese patent medicines containing volatile oils in this paper, and then established an information sheet covering such items as name, dosage, dosage form, specification and usage, and main functions. Subsequently, on the basis of the multidisciplinary knowledge of pharmaceutics, traditional Chinese pharmacology and basic theory of traditional Chinese medicine, efforts were also made in the statistics of the dosage form and usage, variety of volatile oils and main functions, as well as the status analysis on volatile oils in terms of the dosage form development, prescription development, drug instruction and quality control, in order to lay a foundation for the further exploration of the market development situations of volatile oils and the future development orientation.

Characterization of trace organic compounds associated with aged and diluted sidestream tobacco smoke in a controlled atmosphere—volatile organic compounds and polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Baek, Sung-Ok; Jenkins, Roger A.

In this study, a wide range of volatile organic constituents of aged and diluted sidestream tobacco smoke (ADSS) were determined in a controlled atmosphere, where ADSS is the sole source of target compounds. The ADSS was generated in a 30 m 3 environmental test chamber using a variety of cigarettes, including the Kentucky 1R4F reference cigarette and eight commercial brands, and a total of 24 experimental runs were conducted. Target analytes were divided into three groups, i.e. vapor and particulate phase markers for environmental tobacco smoke (ETS), volatile organic compounds (VOC) including carbonyls, and polycyclic aromatic hydrocarbons (PAH). The VOC samples were collected on triple sorbent traps, and then analyzed by thermal desorption coupled with gas chromatography/mass spectrometry (GC/MS), while the carbonyl compounds were sampled on DNPH cartridges, being analyzed by HPLC. ETS particles in the chamber were collected by high volume sampling, and then used for the determination of PAHs by GC/MS. Among more than 30 target VOCs, acetaldehyde appeared to be the most abundant compound, followed by 2-methyl-1,3-butadiene, and formaldehyde. The results from the chamber study were further used to generate characterized ratios of selected VOCs to 3-ethenyl pyridine (3-EP), a vapor phase ETS marker. The ratios appeared to be in generally good agreement with published values in the literature. This suggests that the characteristic ratios may be useful for quantifying the impact of ETS on the VOC concentrations in 'real world' indoor environments, which are affected by a complex mixture of components from multiple sources. The yields of ETS markers from this study are all slightly lower than those estimated by other studies, while VOC yields are in reasonable agreement in many cases with values in the literature. Among 16 target PAHs, chrysene appeared to be most abundant, followed by benzo(a)anthracene (BaA) and benzo(a)pyrene (BaP). The average contents of BaP and BaA in ADSS particles for the commercial brands were 12.8 and 21.5 μg g -1, respectively. These values are all approximately 1.5-3 times higher than those determined previously by other studies. The average yields of BaP per cigarette were estimated to be 209 and 215 ng for the reference and commercial cigarettes, respectively. Comparison of the PAH data from this study with literature values was complicated by a lack of consistency in cigarette smoke generating methodology among other studies. These data on the cigarette yields of ETS components may provide useful information to studies on the mathematical modeling of indoor air quality regarding tobacco smoke as a source of interest, or to studies on the assessment of human exposure to ETS.

Biodegradation of Aromatic Compounds by Escherichia coli

PubMed Central

Díaz, Eduardo; Ferrández, Abel; Prieto, María A.; García, José L.

2001-01-01

Although Escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. This review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by E. coli. After giving a general overview of the aromatic compounds that E. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on the genes and proteins involved in the catabolism of such compounds, namely, several aromatic acids (phenylacetic acid, 3- and 4-hydroxyphenylacetic acid, phenylpropionic acid, 3-hydroxyphenylpropionic acid, and 3-hydroxycinnamic acid) and amines (phenylethylamine, tyramine, and dopamine). Other enzymatic activities acting on aromatic compounds in E. coli are also reviewed and evaluated. The review also reflects the present impact of genomic research and how the analysis of the whole E. coli genome reveals novel aromatic catabolic functions. Moreover, evolutionary considerations derived from sequence comparisons between the aromatic catabolic clusters of E. coli and homologous clusters from an increasing number of bacteria are also discussed. The recent progress in the understanding of the fundamentals that govern the degradation of aromatic compounds in E. coli makes this bacterium a very useful model system to decipher biochemical, genetic, evolutionary, and ecological aspects of the catabolism of such compounds. In the last part of the review, we discuss strategies and concepts to metabolically engineer E. coli to suit specific needs for biodegradation and biotransformation of aromatics and we provide several examples based on selected studies. Finally, conclusions derived from this review may serve as a lead for future research and applications. PMID:11729263

Determination of a wide range of volatile organic compounds in ambient air using multisorbent adsorption/thermal desorption and gas chromatography/mass spectrometry

USGS Publications Warehouse

Pankow, J.F.; Luo, W.; Isabelle, L.M.; Bender, D.A.; Baker, R.J.

1998-01-01

Adsorption/thermal desorption with multisorbent air-sampling cartridges was developed for the determination of 87 method analytes including halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. The volatilities of the compounds ranged from that of dichlorofluoromethane (CFC12) to that of 1,2,3- trichlorobenzene. The eight most volatile compounds were determined using a 1.5-L air sample and a sample cartridge containing 50 mg of Carbotrap B and 280 mg of Carboxen 1000; the remaining 79 compounds were determined using a 5-L air sample and a cartridge containing 180 mg of Carbotrap B and 70 mg of Carboxen 1000. Analysis and detection were by gas chromatography/mass spectrometry. The minimum detectable level (MDL) concentration values ranged from 0.01 parts per billion by volume (ppbv) for chlorobenzene to 0.4 ppbv for bromomethane; most of the MDL values were in the range 0.02-0.06 ppbv. No breakthrough was detected with the prescribed sample volumes. Analyte stability on the cartridges was very good. Excellent recoveries were obtained with independent check standards. Travel spike recoveries ranged from 90 to 110% for 72 of the 87 compounds. The recoveries were less than 70% for bromomethane and chloroethene and for a few compounds such as methyl acetate that are subject to losses by hydrolysis; the lowest travel spike recovery was obtained for bromomethane (62%). Blank values for all compounds were either below detection or very low. Ambient atmospheric sampling was conducted in New Jersey from April to December, 1997. Three sites characterized by low, moderate, and high densities of urbanization/traffic were sampled. The median detected concentrations of the compounds were either similar at all three sites (as with the chlorofluorocarbon compounds) or increased with the density of urbanization/traffic (as with dichloromethane, MTBE, benzene, and toluene). For toluene, the median detected concentrations were 0.23, 0.42, and 0.70 ppbv at the three sites. Analytical precision was measured using duplicate sampling. As expected, the precision deteriorated with decreasing concentration. At concentrations greater than 0.2 ppbv, most duplicates differed by less than 20%; below the MDL values, the differences between the duplicates were larger, but they were still typically less than 40%.

User’s guide to the collection and analysis of tree cores to assess the distribution of subsurface volatile organic compounds

USGS Publications Warehouse

Vroblesky, Don A.

2008-01-01

Analysis of the volatile organic compound content of tree cores is an inexpensive, rapid, simple approach to examining the distribution of subsurface volatile organic compound contaminants. The method has been shown to detect several volatile petroleum hydrocarbons and chlorinated aliphatic compounds associated with vapor intrusion and ground-water contamination. Tree cores, which are approximately 3 inches long, are obtained by using an increment borer. The cores are placed in vials and sealed. After a period of equilibration, the cores can be analyzed by headspace analysis gas chromatography. Because the roots are exposed to volatile organic compound contamination in the unsaturated zone or shallow ground water, the volatile organic compound concentrations in the tree cores are an indication of the presence of subsurface volatile organic compound contamination. Thus, tree coring can be used to detect and map subsurface volatile organic compound contamination. For comparison of tree-core data at a particular site, it is important to maintain consistent methods for all aspects of tree-core collection, handling, and analysis. Factors affecting the volatile organic compound concentrations in tree cores include the type of volatile organic compound, the tree species, the rooting depth, ground-water chemistry, the depth to the contaminated horizon, concentration differences around the trunk related to variations in the distribution of subsurface volatile organic compounds, concentration differences with depth of coring related to volatilization loss through the bark and possibly other unknown factors, dilution by rain, seasonal influences, sorption, vapor-exchange rates, and within-tree volatile organic compound degradation.

Identification of a plastidial phenylalanine exporter that influences flux distribution through the phenylalanine biosynthetic network

PubMed Central

Widhalm, Joshua R.; Gutensohn, Michael; Yoo, Heejin; Adebesin, Funmilayo; Qian, Yichun; Guo, Longyun; Jaini, Rohit; Lynch, Joseph H.; McCoy, Rachel M.; Shreve, Jacob T.; Thimmapuram, Jyothi; Rhodes, David; Morgan, John A.; Dudareva, Natalia

2015-01-01

In addition to proteins, L-phenylalanine is a versatile precursor for thousands of plant metabolites. Production of phenylalanine-derived compounds is a complex multi-compartmental process using phenylalanine synthesized predominantly in plastids as precursor. The transporter(s) exporting phenylalanine from plastids, however, remains unknown. Here, a gene encoding a Petunia hybrida plastidial cationic amino-acid transporter (PhpCAT) functioning in plastidial phenylalanine export is identified based on homology to an Escherichia coli phenylalanine transporter and co-expression with phenylalanine metabolic genes. Radiolabel transport assays show that PhpCAT exports all three aromatic amino acids. PhpCAT downregulation and overexpression result in decreased and increased levels, respectively, of phenylalanine-derived volatiles, as well as phenylalanine, tyrosine and their biosynthetic intermediates. Metabolic flux analysis reveals that flux through the plastidial phenylalanine biosynthetic pathway is reduced in PhpCAT RNAi lines, suggesting that the rate of phenylalanine export from plastids contributes to regulating flux through the aromatic amino-acid network. PMID:26356302

Identification of a plastidial phenylalanine exporter that influences flux distribution through the phenylalanine biosynthetic network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Widhalm, Joshua R.; Gutensohn, Michael; Yoo, Heejin

In addition to proteins, L-phenylalanine is a versatile precursor for thousands of plant metabolites. Production of phenylalanine-derived compounds is a complex multi-compartmental process using phenylalanine synthesized predominantly in plastids as precursor. The transporter(s) exporting phenylalanine from plastids, however, remains unknown. Here, a gene encoding a Petunia hybrida plastidial cationic amino-acid transporter (PhpCAT) functioning in plastidial phenylalanine export is identified based on homology to an Escherichia coli phenylalanine transporter and co-expression with phenylalanine metabolic genes. Radiolabel transport assays show that PhpCAT exports all three aromatic amino acids. PhpCAT downregulation and overexpression result in decreased and increased levels, respectively, of phenylalanine-derived volatiles,more » as well as phenylalanine, tyrosine and their biosynthetic intermediates. Metabolic flux analysis reveals that flux through the plastidial phenylalanine biosynthetic pathway is reduced in PhpCAT RNAi lines, suggesting that the rate of phenylalanine export from plastids contributes to regulating flux through the aromatic amino-acid network.« less

Identification of a plastidial phenylalanine exporter that influences flux distribution through the phenylalanine biosynthetic network

DOE PAGES

Widhalm, Joshua R.; Gutensohn, Michael; Yoo, Heejin; ...

2015-09-10

In addition to proteins, L-phenylalanine is a versatile precursor for thousands of plant metabolites. Production of phenylalanine-derived compounds is a complex multi-compartmental process using phenylalanine synthesized predominantly in plastids as precursor. The transporter(s) exporting phenylalanine from plastids, however, remains unknown. Here, a gene encoding a Petunia hybrida plastidial cationic amino-acid transporter (PhpCAT) functioning in plastidial phenylalanine export is identified based on homology to an Escherichia coli phenylalanine transporter and co-expression with phenylalanine metabolic genes. Radiolabel transport assays show that PhpCAT exports all three aromatic amino acids. PhpCAT downregulation and overexpression result in decreased and increased levels, respectively, of phenylalanine-derived volatiles,more » as well as phenylalanine, tyrosine and their biosynthetic intermediates. Metabolic flux analysis reveals that flux through the plastidial phenylalanine biosynthetic pathway is reduced in PhpCAT RNAi lines, suggesting that the rate of phenylalanine export from plastids contributes to regulating flux through the aromatic amino-acid network.« less

Carbonyl atmospheric reaction products of aromatic hydrocarbons in ambient air

NASA Astrophysics Data System (ADS)

Obermeyer, Genevieve; Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

To convert gaseous carbonyls to oximes during sampling, an XAD-4 resin denuder system pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and followed by analysis with methane positive chemical ionization gas chromatography/mass spectrometry was used to measure carbonyls in ambient air samples in Riverside, CA. In conjunction with similar analyses of environmental chamber OH radical-initiated reactions of o- and p-xylene, 1,2,4-trimethylbenzene, ethylbenzene, 4-hydroxy-2-butanone and 1,4-butanediol, we identified benzaldehyde, o-, m- and p-tolualdehyde and acetophenone and the dicarbonyls glyoxal, methylglyoxal, biacetyl, ethylglyoxal, 1,4-butenedial, 3-hexene-2,5-dione, 3-oxo-butanal, 1,4-butanedial and malonaldehyde in the ambient air samples. As discussed, these carbonyls and dicarbonyls can be formed from the OH radical-initiated reactions of aromatic hydrocarbons and other volatile organic compounds emitted into the atmosphere, and we conclude that in situ atmospheric formation is a major source of these carbonyls in our Riverside, CA, ambient air samples.

FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND CARBONACEOUS SOLIDS IN GAS-PHASE CONDENSATION EXPERIMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaeger, C.; Huisken, F.; Henning, Th.

2009-05-01

Carbonaceous grains represent a major component of cosmic dust. In order to understand their formation pathways, they have been prepared in the laboratory by gas-phase condensation reactions such as laser pyrolysis and laser ablation. Our studies demonstrate that the temperature in the condensation zone determines the formation pathway of carbonaceous particles. At temperatures lower than 1700 K, the condensation by-products are mainly polycyclic aromatic hydrocarbons (PAHs) that are also the precursors or building blocks for the condensing soot grains. The low-temperature condensates contain PAH mixtures that are mainly composed of volatile three to five ring systems. At condensation temperatures highermore » than 3500 K, fullerene-like carbon grains and fullerene compounds are formed. Fullerene fragments or complete fullerenes equip the nucleating particles. Fullerenes can be identified as soluble components. Consequently, condensation products in cool and hot astrophysical environments such as cool and hot asymptotic giant branch stars or Wolf-Rayet stars should be different and should have distinct spectral properties.« less

Simple procedures for enrichment of chlorinated aromatic pollutants from fat, water and milk for subsequent analysis by high-resolution methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Egestad, B.; Curstedt, T.; Sjoevall, J.

1982-01-01

Procedures for enrichment of non-volatile chlorinated aromatic pollutants from fat, water and milk are described. /sup 14/C-DDT was used as a model compound in recovery experiments. A several thousand-fold enrichment of DDT added to butter was achieved by two consecutive straight-phase chromatographies on Lipidex 5000. Trace amounts of DDT in liter volumes of water could be quantitatively extracted by rapid filtration through 2 ml beds of Lipidex 1000. A batch extraction procedure permitted enrichment of DDT from milk after addition of n-pentylamine, methanol and water. DDT could then be eluted from the gel with retention of more than 90% ofmore » the lipids. A reversed-phase system with Lipidex 5000 could be used for separation of TCDD from DDT and PCBs. The liquid-gel chromatographic procedures are simple and suitable for clean-up of samples prior to application of high-resolution methods. 5 tables.« less

Composition and emission dynamics of migratory locust volatiles in response to changes in developmental stages and population density.

PubMed

Wei, Jianing; Shao, Wenbo; Wang, Xianhui; Ge, Jin; Chen, Xiangyong; Yu, Dan; Kang, Le

2017-02-01

Chemical communication plays an important role in density-dependent phase change in locusts. However, the volatile components and emission patterns of the migratory locust, Locusta migratoria, are largely unknown. In this study, we identified the chemical compositions and emission dynamics of locust volatiles from the body and feces and associated them with developmental stages, sexes and phase changes. The migratory locust shares a number of volatile components with the desert locust (Schistocerca gregaria), but the emission dynamics of the two locust species are significantly different. The body odors of the gregarious nymphs in the migratory locust consisted of phenylacetonitrile (PAN), benzaldehyde, guaiacol, phenol, aliphatic acids and 2,3-butanediol, and PAN was the dominant volatile. Volatiles from the fecal pellets of the nymphs primarily consist of guaiacol and phenol. Principal component analysis (PCA) showed significant differences in the volatile profiles between gregarious and solitary locusts. PAN and 4-vinylanisole concentrations were significantly higher in gregarious individuals than in solitary locusts. Gregarious mature males released significantly higher amounts of PAN and 4-vinylanisole during adulthood than mature females and immature adults of both sexes. Furthermore, PAN and 4-vinylanisole were completely lost in gregarious nymphs during the solitarization process, but were obtained by solitary nymphs during gregarization. The amounts of benzaldehyde, guaiacol and phenol only unidirectionally decreased from solitary to crowded treatment. Aliphatic aldehydes (C7 to C10), which were previously reported as locust volatiles, are now identified as environmental contaminants. Therefore, our results illustrate the precise odor profiles of migratory locusts during developmental stages, sexes and phase change. However, the function and role of PAN and other aromatic compounds during phase transition need further investigation. © 2016 Institute of Zoology, Chinese Academy of Sciences.

AGRONOMIC OPTIMIZATION FOR PHYTOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBONS

EPA Science Inventory

Phytoremediation is a low-cost method of using plants to degrade, volatilize or sequester organic and metal pollutants that has been used in efforts to remediate sites contaminated with polycyclic aromatic hydrocarbon (PAH) refinery wastes. Non-native plant species aggressivel...

Production of sensory compounds by means of the yeast Dekkera bruxellensis in different nitrogen sources with the prospect of producing cachaça.

PubMed

Castro Parente, Denise; Vidal, Esteban Espinosa; Leite, Fernanda Cristina Bezerra; de Barros Pita, Will; de Morais, Marcos Antonio

2015-01-01

The distilled spirit made from sugar cane juice, also known as cachaça, is a traditional Brazilian beverage that in recent years has increased its market share among international distilled beverages. Several volatile compounds produced by yeast cells during the fermentation process are responsible for the unique taste and aroma of this drink. The yeast Dekkera bruxellensis has acquired increasing importance in the fermented beverage production, as the different metabolites produced by this yeast may be either beneficial or harmful to the end-product. Since D. bruxellensis is often found in the fermentation processes carried out in ethanol fuel distillation in Brazil, we employed this yeast to analyse the physiological profile and production of aromatic compounds and to examine whether it is feasible to regard it as a cachaça-producing microorganism. The assays were performed on a small scale and simulated the conditions for the production of handmade cachaça. The results showed that the presence of aromatic and branched-chain amino acids in the medium has a strong influence on the metabolism and production of flavours by D. bruxellensis. The assimilation of these alternative nitrogen sources led to different fermentation yields and the production of flavouring compounds. The influence of the nitrogen source on the metabolism of fusel alcohols and esters in D. bruxellensis highlights the need for further studies of the nitrogen requirements to obtain the desired level of sensory compounds in the fermentation. Our results suggest that D. bruxellensis has the potential to play a role in the production of cachaça. Copyright © 2014 John Wiley & Sons, Ltd.

Determination of polar organic solutes in oil-shale retort water

USGS Publications Warehouse

Leenheer, J.A.; Noyes, T.I.; Stuber, H.A.

1982-01-01

A variety of analytical methods were used to quantitatively determine polar organic solutes in process retort water and a gas-condensate retort water produced in a modified in situ oil-shale retort. Specific compounds accounting for 50% of the dissolved organic carbon were identified in both retort waters. In the process water, 42% of the dissolved organic carbon consisted of a homologous series of fatty acids from C2 to C10. Dissolved organic carbon percentages for other identified compound classes were as follows: aliphatic dicarboxylic acids, 1.4%; phenols, 2.2%; hydroxypyridines, 1.1%; aliphatic amides, 1.2%. In the gas-condensate retort water, aromatic amines were most abundant at 19.3% of the dissolved organic carbon, followed by phenols (17.8%), nitriles (4.3%), aliphatic alcohols (3.5%), aliphatic ketones (2.4%), and lactones (1.3%). Steam-volatile organic solutes were enriched in the gas-condensate retort water, whereas nonvolatile acids and polyfunctional neutral compounds were predominant organic constituents of the process retort water.

[Analyze on volatile compounds of Antrodia camphorata using HS-SPME-GC-MS].

PubMed

He, Zhe; Lu, Zhen-Ming; Xu, Hong-Yu; Shi, Jing-Song; Xu, Zheng-Hong

2011-11-01

To analyze the volatile compounds of Antrodia camphorata in solid-state and submerged cultures. A headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry(GC-MS) were used to evaluate the profile of the volatile compounds. 49 volatile compounds were identified in A. camphorata mycelia in submerged culture, while 43 volatile compounds were identified in mycelia in solid-state culture. 1-octen-3-ol, 3-octanone, 1-octen-3-ylacetate, acetic acid octyl ester and ethanol were the main volatile compounds in A. camphorata mycelia in submerged culture, while 1-octen-3-ol, 3-octanone, 3-methyl-butyraldenhyde, gamma-podecalactone and methyl 2-furozte were the most potent key volatile compounds in mycelia in solid-state culture. The volatile compounds in the mycelia of A. camphorata in solid-state and submerged cultures are similar but their relative contents are different.

How the Addition of Spices and Herbs to Virgin Olive Oil to Produce Flavored Oils Affects Consumer Acceptance.

PubMed

Issaoui, Manel; Flamini, Guido; Souid, Sondess; Bendini, Alessandra; Barbieri, Sara; Gharbi, Ines; Toschi, Tullia Gallina; Cioni, Pier Luigi; Hammami, Mohamed

2016-06-01

With the aim to expand the olive oil market to a larger number of consumers who are not familiar with the sensory characteristics of virgin olive oil, the use of novel products known as "flavored olive oils", obtained by adding different kind of spices and aromatic herbs, is spreading in many countries. In order to test consumer acceptability of this type of product, in a country (Tunisia) in which virgin olive oil is regularly consumed, flavored olive oils were prepared by adding aromatic extracts of thyme, oregano, a mix of herbs (used as pizza seasoning), rosemary, and basil to a monovarietal Chemlali virgin olive oil and a consumer test on 206 subjects was performed. Selected quality parameters (free acidity, peroxide number, oxidative stability, specific absorption at K232 nm and K270 nm) were also measured and no significant variations were detected. Slight differences were found concerning the content of minor compounds (chlorophylls, carotenoids and total phenols). On the other hand, notable differences were seen in the profiles of volatile compounds, which appeared to be responsible for the observed variability in consumer acceptance. Although the unflavored oil was more appreciated than the flavored ones, among the latter, thyme flavored olive oil was the most appreciated.

Molecular Characterization of Brown Carbon in Biomass Burning Aerosol Particles.

PubMed

Lin, Peng; Aiona, Paige K; Li, Ying; Shiraiwa, Manabu; Laskin, Julia; Nizkorodov, Sergey A; Laskin, Alexander

2016-11-01

Emissions from biomass burning are a significant source of brown carbon (BrC) in the atmosphere. In this study, we investigate the molecular composition of freshly emitted biomass burning organic aerosol (BBOA) samples collected during test burns of sawgrass, peat, ponderosa pine, and black spruce. We demonstrate that both the BrC absorption and the chemical composition of light-absorbing compounds depend significantly on the type of biomass fuels. Common BrC chromophores in the selected BBOA samples include nitro-aromatics, polycyclic aromatic hydrocarbon derivatives, and polyphenols spanning a wide range of molecular weights, structures, and light absorption properties. A number of biofuel-specific BrC chromophores are observed, indicating that some of them may be used as source-specific markers of BrC. On average, ∼50% of the light absorption in the solvent-extractable fraction of BBOA can be attributed to a limited number of strong BrC chromophores. The absorption coefficients of BBOA are affected by solar photolysis. Specifically, under typical atmospheric conditions, the 300 nm absorbance decays with a half-life of ∼16 h. A "molecular corridor" analysis of the BBOA volatility distribution suggests that many BrC compounds in the fresh BBOA have low saturation mass concentration (<1 μg m -3 ) and will be retained in the particle phase under atmospherically relevant conditions.

Screening complex hazardous wastes for mutagenic activity using a modified version of the TLC/Salmonella assay.

PubMed

Houk, V S; Claxton, L D

1986-03-01

10 complex hazardous wastes were tested for mutagenic activity using a modified version of the TLC/Salmonella assay developed by Bjørseth et al. (1982). This fractionation/bioassay scheme couples thin-layer chromatography (TLC) with the Salmonella/mammalian-microsome (Ames) assay for the detection of mutagenic constituents in complex mixtures. Crude (unadulterated) hazardous wastes and selected hazardous waste extracts were fractionated on commercially available cellulose TLC plates. Mutagenicity testing was performed in situ by applying a single overlay of minimal growth agar, tester strain TA98 or TA100, and the optional metabolic activation system directly onto the developed chromatogram. A mutagenic effect was indicated either by the appearance of localized clusters of revertant colonies or by an increase in total revertant growth vis-à-vis control plates. 7 of 10 hazardous wastes (including tars, emulsions, sludges, and spent acids and caustics) demonstrated mutagenic activity when tested by this method. To assess the sensitivity of the modified TLC/Salmonella assay, 14 Salmonella mutagens from a wide range of chemical classes and polarities were tested. Selected compounds included heterocyclics, aromatic amines, alkylating agents, antitumor agents, a nitrosamine and a nitroaromatic. 11 of the 14 mutagens were positive in this test system. The 3 compounds refractory to analysis included a polycyclic aromatic hydrocarbon and two volatiles.

Employing CO2 as reaction medium for in-situ suppression of the formation of benzene derivatives and polycyclic aromatic hydrocarbons during pyrolysis of simulated municipal solid waste.

PubMed

Lee, Jechan; Choi, Dongho; Tsang, Yiu Fai; Oh, Jeong-Ik; Kwon, Eilhann E

2017-05-01

This study proposes a strategic principle to enhance the thermal efficiency of pyrolysis of municipal solid waste (MSW). An environmentally sound energy recovery platform was established by suppressing the formation of harmful organic compounds evolved from pyrolysis of MSW. Using CO 2 as reaction medium/feedstock, CO generation was enhanced through the following: 1) expediting the thermal cracking of volatile organic carbons (VOCs) evolved from the thermal degradation of the MSWs and 2) directly reacting VOCs with CO 2 . This particular influence of CO 2 on pyrolysis of the MSWs also led to the in-situ mitigation of harmful organic compounds (e.g., benzene derivatives and polycyclic aromatic hydrocarbons (PAHs)) considering that CO 2 acted as a carbon scavenger to block reaction pathways toward benzenes and PAHs in pyrolysis. To understand the fundamental influence of CO 2 , simulated MSWs (i.e., various ratios of biomass to polymer) were used to avoid any complexities arising from the heterogeneous matrix of MSW. All experimental findings in this study suggested the foreseeable environmental application of CO 2 to energy recovery from MSW together with disposal of MSW. Copyright © 2017 Elsevier Ltd. All rights reserved.

Origin and distribution of thiophenes and furans in gas discharges from active volcanoes and geothermal systems.

PubMed

Tassi, Franco; Montegrossi, Giordano; Capecchiacci, Francesco; Vaselli, Orlando

2010-03-31

The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C(2)-C(20) species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C(4)H(8)O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection.

Origin and Distribution of Thiophenes and Furans in Gas Discharges from Active Volcanoes and Geothermal Systems

PubMed Central

Tassi, Franco; Montegrossi, Giordano; Capecchiacci, Francesco; Vaselli, Orlando

2010-01-01

The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C2–C20 species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C4H8O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection. PMID:20480029

A volatolomic approach for studying plant variability: the case of selected Helichrysum species (Asteraceae).

PubMed

Giuliani, Claudia; Lazzaro, Lorenzo; Calamassi, Roberto; Calamai, Luca; Romoli, Riccardo; Fico, Gelsomina; Foggi, Bruno; Mariotti Lippi, Marta

2016-10-01

The species of Helichrysum sect. Stoechadina (Asteraceae) are well-known for their secondary metabolite content and the characteristic aromatic bouquets. In the wild, populations exhibit a wide phenotypic plasticity which makes critical the circumscription of species and infraspecific ranks. Previous investigations on Helichrysum italicum complex focused on a possible phytochemical typification based on hydrodistilled essential oils. Aims of this paper are three-fold: (i) characterizing the volatile profiles of different populations, testing (ii) how these profiles vary across populations and (iii) how the phytochemical diversity may contribute in solving taxonomic problems. Nine selected Helichrysum populations, included within the H. italicum complex, Helichrysum litoreum and Helichrysum stoechas, were investigated. H. stoechas was chosen as outgroup for validating the method. After collection in the wild, plants were cultivated in standard growing conditions for over one year. Annual leafy shoots were screened in the post-blooming period for the emissions of volatile organic compounds (VOCs) by means of headspace solid phase microextraction coupled with gas-chromatography and mass spectrometry (HS-SPME-GC/MS). The VOC composition analysis revealed the production of overall 386 different compounds, with terpenes being the most represented compound class. Statistical data processing allowed the identification of the indicator compounds that differentiate the single populations, revealing the influence of the geographical provenance area in determining the volatile profiles. These results suggested the potential use of VOCs as valuable diacritical characters in discriminating the Helichrysum populations. In addition, the cross-validation analysis hinted the potentiality of this volatolomic study in the discrimination of the Helichrysum species and subspecies, highlighting a general congruence with the current taxonomic treatment of the genus. The consistency between this phytochemical approach and the traditional morphometrical analysis in studying the Helichrysum populations supports the validity of the VOC profile in solving taxonomic problems. Copyright © 2016 Elsevier Ltd. All rights reserved.

A study revealing the key aroma compounds of steamed bread made by Chinese traditional sourdough*

PubMed Central

Zhang, Guo-hua; Wu, Tao; Sadiq, Faizan A.; Yang, Huan-yi; Liu, Tong-jie; Ruan, Hui; He, Guo-qing

2016-01-01

Aroma of Chinese steamed bread (CSB) is one of the important parameters that determines the overall quality attributes and consumer acceptance. However, the aroma profile of CSB still remains poorly understood, mainly because of relying on only a single method for aroma extraction in previous studies. Therefore, the objective of this study was to determine the volatile aroma compounds of five different samples of CSB using three different aroma extraction methods, namely solid-phase microextraction (SPME), simultaneous distillation–extraction (SDE), and purge and trap (P&T). All samples showed a unique aroma profile, which could be attributed to their unique microbial consortia. (E)-2-Nonenal and (E,E)-2,4-decadienal were the most prevalent aromatic compounds revealed by SDE, which have not been reported previously, while ethanol and acetic acid proved to be the most dominant compounds by both SPME and P&T. Our approach of combining three different aroma extraction methods provided better insights into the aroma profile of CSB, which had remained largely unknown in previous studies. PMID:27704748

Spectroscopic characterization of digestates obtained from sludge mixed to increasing amounts of fruit and vegetable wastes

NASA Astrophysics Data System (ADS)

Provenzano, Maria Rosaria; Cavallo, Ornella; Malerba, Anna Daniela; Di Maria, Francesco; Ricci, Anna; Gigliotti, Giovanni

2015-04-01

Anaerobic digestion (AD) represents an efficient waste-treatment technology during which microorganisms break down biodegradable material in absence of oxygen yielding a biogas containing methane. The aim of this work was to investigate the transformations occurring in the organic matter during the co-digestion of waste mixed sludge (WMS) with an increasing amount of fruit and vegetable wastes (FVW) in a pilot scale apparatus reproducing a full-scale digester in an existing wastewater treatment plant. Samples comprised: sludge, FVW, sludge mixed with 10-20-30-40% FVW. Ingestates and digestates were analyzed by means of emission fluorescence spectroscopy and FTIR associated to Fourier self deconvolution (FSD) of spectra. With increasing the amount of FVW from 10% to 20% at which percentage biogas production reached the maximum value, FTIR spectra and FSD traces of digestates exhibited a decrease of intensity of peaks assigned to polysaccharides and aliphatics and an increase of peak assigned to aromatics as a result of the biodegradation of rapidly degradable materials and concentration of aromatic recalcitrant compounds. Digestates with 30 and 40% FVW exhibited a relative increase of intensity of peaks assigned to aliphatics likely as a result of the increasing amount of rapidly degradable materials and the consequent reduction of the hydraulic retention time. This may cause inhibition of methanogenesis and accumulation of volatile fatty acids. The highest emission fluorescence intensity was observed for the digestate with 20% FVW confirming the concentration of aromatic recalcitrant compounds in the substrate obtained at the highest biogas production.

Characterization of the major fragance gene from an aromatic japonica rice and analysis of its diversity in Asian cultivated rice

PubMed Central

Bourgis, F.; Guyot, R.; Gherbi, H.; Tailliez, E.; Amabile, I.; Salse, J.; Lorieux, M.; Delseny, M.

2008-01-01

In Asian cultivated rice (Oryza sativa L.), aroma is one of the most valuable traits in grain quality and 2-ACP is the main volatile compound contributing to the characteristic popcorn-like odour of aromatic rices. Although the major locus for grain fragrance (frg gene) has been described recently in Basmati rice, this gene has not been characterised in true japonica varieties and molecular information available on the genetic diversity and evolutionary origin of this gene among the different varieties is still limited. Here we report on characterisation of the frg gene in the Azucena variety, one of the few aromatic japonica cultivars. We used a RIL population from a cross between Azucena and IR64, a non-aromatic indica, the reference genomic sequence of Nipponbare (japonica) and 93–11 (indica) as well as an Azucena BAC library, to identify the major fragance gene in Azucena. We thus identified a betaine aldehyde dehydrogenase gene, badh2, as the candidate locus responsible for aroma, which presented exactly the same mutation as that identified in Basmati and Jasmine-like rices. Comparative genomic analyses showed very high sequence conservation between Azucena and Nipponbare BADH2, and a MITE was identified in the promotor region of the BADH2 allele in 93–11. The badh2 mutation and MITE were surveyed in a representative rice collection, including traditional aromatic and non-aromatic rice varieties, and strongly suggested a monophylogenetic origin of this badh2 mutation in Asian cultivated rices. Altogether these new data are discussed here in the light of current hypotheses on the origin of rice genetic diversity. PMID:18491070

Inhibition of melanogenesis versus antioxidant properties of essential oil extracted from leaves of Vitex negundo Linn and chemical composition analysis by GC-MS.

PubMed

Huang, Huey-Chun; Chang, Tzu-Yun; Chang, Long-Zen; Wang, Hsiao-Fen; Yih, Kuang-Hway; Hsieh, Wan-Yu; Chang, Tsong-Min

2012-03-30

This study was aimed at investigating the antimelanogenic and antioxidative properties of the essential oil extracted from leaves of V. negundo Linn and the analysis of the chemical composition of this essential oil. The efficacy of the essential oil was evaluated spectrophotometrically, whereas the volatile chemical compounds in the essential oil were analyzed by gas chromatography-mass spectrometry (GC-MS). The results revealed that the essential oil effectively suppresses murine B16F10 tyrosinase activity and decreases the amount of melanin in a dose-dependent manner. Additionally, the essential oil significantly scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals, and showed potent reducing power versus metal-ion chelating properties in a dose-dependent pattern. The chemical constituents in the essential oil are sesquiterpenes (44.41%), monoterpenes (19.25%), esters (14.77%), alcohols (8.53%), aromatic compound (5.90%), ketone (4.96%), ethers (0.4%) that together account for 98.22% of its chemical composition. It is predicted that the aromatic compound in the essential oil may contribute to its antioxidant activities. The results indicated that essential oil extracted from V. negundo Linn leaves decreased melanin production in B16F10 melanoma cells and showed potent antioxidant activities. The essential oil can thereby serve as an inhibitor of melanin synthesis and could also act as a natural antioxidant.

An evaluation of electronic cigarette formulations and aerosols for harmful and potentially harmful constituents (HPHCs) typically derived from combustion.

PubMed

Wagner, Karl A; Flora, Jason W; Melvin, Matt S; Avery, Karen C; Ballentine, Regina M; Brown, Anthony P; McKinney, Willie J

2018-06-01

U.S. FDA draft guidance recommends reporting quantities of designated harmful and potentially harmful constituents (HPHCs) in e-cigarette e-liquids and aerosols. The HPHC list comprises potential matrix-related compounds, flavors, nicotine, tobacco-related impurities, leachables, thermal degradation products, and combustion-related compounds. E-cigarettes contain trace levels of many of these constituents due to tobacco-derived nicotine and thermal degradation. However, combustion-related HPHCs are not likely to be found due to the relatively low operating temperatures of most e-cigarettes. The purpose of this work was to use highly sensitive, selective, and validated analytical methods to determine if these combustion-related HPHCs (three aromatic amines, five volatile organic compounds, and the polycyclic aromatic hydrocarbon benzo[a]pyrene) are detectable in commercial refill e-liquids, reference e-cigarette e-liquids, and aerosols generated from rechargeable e-cigarettes with disposable cartridges (often referred to as "cig-a-likes"). In addition, the transfer efficiency of these constituents from e-liquid to aerosol was evaluated when these HPHCs were added to the e-liquids prior to aerosol formation. This work demonstrates that combustion-related HPHCs are not present at measurable levels in the commercial and reference e-liquids or e-cigarette aerosols tested. Additionally, when combustion-related HPHCs are added to the e-liquids, they transfer to the aerosol with transfer efficiencies ranging from 49% to 99%. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Process for removing halogenated aliphatic and aromatic compounds from petroleum products

DOEpatents

Googin, J.M.; Napier, J.M.; Travaglini, M.A.

1983-09-20

A process is described for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 1 fig.

Process for removing halogenated aliphatic and aromatic compounds from petroleum products

DOEpatents

Googin, John M.; Napier, John M.; Travaglini, Michael A.

1983-01-01

A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced.

Molecular Diversity of Brown Carbon Chromophores in Biomass Burning Aerosol

NASA Astrophysics Data System (ADS)

Lin, P.; Laskin, A.; Laskin, J.; Fleming, L.; Nizkorodov, S.

2017-12-01

Brown carbon (BrC) is ubiquitous in the atmosphere and significant contributor to climate forcing. Understanding the environmental effects of BrC, its sources, formation, and atmospheric transformation mechanisms requires identification of BrC chromophores and characterization of their light-absorption properties. In this study, we investigate the chemical composition, molecular identity and optical properties of BrC chromophores associated with biomass burning aerosols emitted from burns of different biofuels during the NOAA FIREX/FireLab experiment. The results show that BrC in the biomass burning smoke contains organic compounds of various molecular structures, polarities, and volatilities. The relative contributions to light absorption from different classes of chromophores such as nitro-phenols, polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs and heterocyclic PAHs are quantified and are shown to be diverse among aerosol samples from different biofuel sources. Despite complexity of BrC, grouping its chromophores according to their polarity and volatility may simplify the parameters for modelling input.

Sensing and capture of toxic and hazardous gases and vapors by metal-organic frameworks.

PubMed

Wang, Hao; Lustig, William P; Li, Jing

2018-03-13

Toxic and hazardous chemical species are ubiquitous, predominantly emitted by anthropogenic activities, and pose serious risks to human health and the environment. Thus, the sensing and subsequent capture of these chemicals, especially in the gas or vapor phase, are of extreme importance. To this end, metal-organic frameworks have attracted significant interest, as their high porosity and wide tunability make them ideal for both applications. These tailorable framework materials are particularly promising for the specific sensing and capture of targeted chemicals, as they can be designed to fit a diverse range of required conditions. This review will discuss the advantages of metal-organic frameworks in the sensing and capture of harmful gases and vapors, as well as principles and strategies guiding the design of these materials. Recent progress in the luminescent detection of aromatic and aliphatic volatile organic compounds, toxic gases, and chemical warfare agents will be summarized, and the adsorptive removal of fluorocarbons/chlorofluorocarbons, volatile radioactive species, toxic industrial gases and chemical warfare agents will be discussed.

Differentiation between Flavors of Sweet Orange (Citrus sinensis) and Mandarin (Citrus reticulata).

PubMed

Feng, Shi; Suh, Joon Hyuk; Gmitter, Frederick G; Wang, Yu

2018-01-10

Pioneering investigations referring to citrus flavor have been intensively conducted. However, the characteristic flavor difference between sweet orange and mandarin has not been defined. In this study, sensory analysis illustrated the crucial role of aroma in the differentiation between orange flavor and mandarin flavor. To study aroma, Valencia orange and LB8-9 mandarin were used. Their most aroma-active compounds were preliminarily identified by aroma extract dilution analysis (AEDA). Quantitation of key volatiles followed by calculation of odor activity values (OAVs) further detected potent components (OAV ≥ 1) impacting the overall aromatic profile of orange/mandarin. Follow-up aroma profile analysis revealed that ethyl butanoate, ethyl 2-methylbutanoate, octanal, decanal, and acetaldehyde were essential for orange-like aroma, whereas linalool, octanal, α-pinene, limonene, and (E,E)-2,4-decadienal were considered key components for mandarin-like aroma. Furthermore, an unreleased mandarin hybrid producing fruit with orange-like flavor was used to validate the identification of characteristic volatiles in orange-like aroma.

Evaluation of Beer Fermentation with a Novel Yeast
Williopsis saturnus.

PubMed

Liu, Shao-Quan; Quek, Althea Ying Hui

2016-12-01

The aim of this study is to evaluate the potential of a novel yeast Williopsis saturnus var. mrakii NCYC 500 to produce fruity beer. Fermentation performance of W. mrakii and beer volatile composition were compared against that fermented with Saccharomyces cerevisiae Safale US-05. o Brix, sugar and pH differed significantly between the two types of beer. A total of 8 alcohols, 11 acids, 41 esters, 9 aldehydes, 8 ketones, 21 terpenes and terpenoids, 5 Maillard reaction products and 2 volatile phenolic compounds were detected. Yeast strain Safale US-05 was more capable of producing a wider range of ethyl and other esters, while yeast strain NCYC 500 produced significantly higher amounts of acetate esters. Strain NCYC 500 retained more terpenes and terpenoids, suggesting that the resultant beer could possess more of the aromatic hint of hops. This study showed that W. saturnus var. mrakii NCYC 500 could ferment wort to produce low-alcohol beer with higher levels of acetate esters, terpenes and terpenoids than yeast S. cerevisiae Safale US-05.

Fermentative capabilities and volatile compounds produced by Kloeckera/Hanseniaspora and Saccharomyces yeast strains in pure and mixed cultures during Agave tequilana juice fermentation.

PubMed

González-Robles, Ivonne Wendolyne; Estarrón-Espinosa, Mirna; Díaz-Montaño, Dulce María

2015-09-01

The fermentative and aromatic capabilities of Kloeckera africana/Hanseniaspora vineae K1, K. apiculata/H. uvarum K2, and Saccharomyces cerevisiae S1 and S2 were studied in pure and mixed culture fermentations using Agave tequila juice as the culture medium. In pure and mixed cultures, Kloeckera/Hanseniaspora strains showed limited growth and sugar consumption, as well as low ethanol yield and productivity, compared to S. cerevisiae, which yielded more biomass, ethanol and viable cell concentrations. In pure and mixed cultures, S. cerevisiae presented a similar behaviour reaching high biomass production, completely consuming the sugar, leading to high ethanol production. Furthermore, the presence of S. cerevisiae strains in the mixed cultures promoted the production of higher alcohols, acetaldehyde and ethyl esters, whereas Kloeckera/Hanseniaspora strains stimulated the production of ethyl acetate and 2-phenyl ethyl acetate compounds.

Water- and air-quality monitoring of the Sweetwater Reservoir Watershed, San Diego County, California-Phase One results, continued, 1999-2001

USGS Publications Warehouse

Mendez, Gregory O.; Foreman, William T.; Sidhu, Jagdeep S.; Majewski, Michael S.

2007-01-01

In 1998, the U.S. Geological Survey, in cooperation with the Sweetwater Authority, began a study to assess the overall health of the Sweetwater watershed with respect to chemical contamination. The study included regular sampling of air and water at Sweetwater Reservoir for chemical contaminants, including volatile organic compounds, polycyclic aromatic hydrocarbons, pesticides, and major and trace elements. Background water samples were collected at Loveland Reservoir for volatile organic compounds and pesticides. The purpose of this study was to monitor changes in contaminant composition and concentration in the air and water resulting from the construction and operation of State Route 125 near Sweetwater Reservoir. To accomplish this, the study was divided into two phases. Phase One sampling was designed to establish baseline conditions for target compounds in terms of detection frequency and concentration in air and water. Phase Two sampling is planned to continue at the established monitoring sites during and after construction of State Route 125 to assess the chemical impact this roadway alignment project may have on the water quality in the reservoir. In addition to the ongoing data collection, several special studies were initiated to assess the occurrence of specific chemicals of concern, such as low-use pesticides, trace metals, and wastewater compounds. This report describes the study design, and the sampling and analytical methods, and presents the results for the second and third years of the study (October 1999 to September 2001). Data collected during the first year of sampling (October 1998 to September 1999) were published in 2002.

Cellular and molecular mechanisms in environmental and occupational inhalation toxicology

PubMed Central

Riechelmann, Herbert

2004-01-01

The central issue of this review are inflammatory changes that take place in the mucous membranes of the respiratory tract as a result of inhaled pollutants. Of particular relevance are dusts, SO2, ozone, aldehydes und volatile organic compounds. Bioorganic pollutants, especially fragments of bacteria and fungi, occur predominantly in indoor dusts. They activate the toll-like/IL-1 receptor and lead to the activation of the transcription factor NF-κB for the release of numerous proinflammatory cytokines. Metals are predominant in ambient air dust particles. They induce the release of reactive oxygen species that cause damage to lipids, proteins and the DNA of the cell. As well as NF-κB, transcription factors that foster proliferation are activated via stress activated protein kinases. Organic compounds such as polycyclic aromatic hydrocarbons and nitroso-compounds of incomplete combustion processes activate additional via the cytosolic arylhydrocarbon receptor for detoxification enzymes. Sulphur dioxide leads to acid stress, and ozone to oxidative stress of the cell. This is accompanied by the release of proinflammatory cytokines via stress activated protein kinases. Aldehydes and volatile organic compounds activate the vanilloid receptor of trigeminal nerve fibres and induce a hyperreactivity of the mucous membrane via the release of nerve growth factors. The mechanisms described work synergistically and lead to a chronic inflammatory reaction of the mucous membranes of the upper respiratory tract that is regularly demonstrable in inhabitants of western industrial nations. It is unclear whether we are dealing here with a physiological inflammation or with an at least partially avoidable result of chronic pollutant exposure. PMID:22073044

Analysis of volatile organic compounds released from the decay of surrogate human models simulating victims of collapsed buildings by thermal desorption-comprehensive two-dimensional gas chromatography-time of flight mass spectrometry.

PubMed

Agapiou, A; Zorba, E; Mikedi, K; McGregor, L; Spiliopoulou, C; Statheropoulos, M

2015-07-09

Field experiments were devised to mimic the entrapment conditions under the rubble of collapsed buildings aiming to investigate the evolution of volatile organic compounds (VOCs) during the early dead body decomposition stage. Three pig carcasses were placed inside concrete tunnels of a search and rescue (SAR) operational field terrain for simulating the entrapment environment after a building collapse. The experimental campaign employed both laboratory and on-site analytical methods running in parallel. The current work focuses only on the results of the laboratory method using thermal desorption coupled to comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (TD-GC×GC-TOF MS). The flow-modulated TD-GC×GC-TOF MS provided enhanced separation of the VOC profile and served as a reference method for the evaluation of the on-site analytical methods in the current experimental campaign. Bespoke software was used to deconvolve the VOC profile to extract as much information as possible into peak lists. In total, 288 unique VOCs were identified (i.e., not found in blank samples). The majority were aliphatics (172), aromatics (25) and nitrogen compounds (19), followed by ketones (17), esters (13), alcohols (12), aldehydes (11), sulfur (9), miscellaneous (8) and acid compounds (2). The TD-GC×GC-TOF MS proved to be a sensitive and powerful system for resolving the chemical puzzle of above-ground "scent of death". Copyright © 2015 Elsevier B.V. All rights reserved.

Oxidation of aromatic contaminants coupled to microbial iron reduction

USGS Publications Warehouse

Lovley, D.R.; Baedecker, M.J.; Lonergan, D.J.; Cozzarelli, I.M.; Phillips, E.J.P.; Siegel, D.I.

1989-01-01

THE contamination of sub-surface water supplies with aromatic compounds is a significant environmental concern1,2. As these contaminated sub-surface environments are generally anaerobic, the microbial oxidation of aromatic compounds coupled to nitrate reduction, sulphate reduction and methane production has been studied intensively1-7. In addition, geochemical evidence suggests that Fe(III) can be an important electron acceptor for the oxidation of aromatic compounds in anaerobic groundwater. Until now, only abiological mechanisms for the oxidation of aromatic compounds with Fe(III) have been reported8-12. Here we show that in aquatic sediments, microbial activity is necessary for the oxidation of model aromatic compounds coupled to Fe(III) reduction. Furthermore, a pure culture of the Fe(III)-reducing bacterium GS-15 can obtain energy for growth by oxidizing benzoate, toluene, phenol or p-cresol with Fe(III) as the sole electron acceptor. These results extend the known physiological capabilities of Fe(III)-reducing organisms and provide the first example of an organism of any type which can oxidize an aromatic hydrocarbon anaerobically. ?? 1989 Nature Publishing Group.

Process for removing halogenated aliphatic and aromatic compounds from petroleum products. [Polychlorinated biphenyls; methylene chloride; perchloroethylene; trichlorofluoroethane; trichloroethylene; chlorobenzene

DOEpatents

Googin, J.M.; Napier, J.M.; Travaglini, M.A.

1982-03-31

A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contracting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible polyhydroxy compound, such as, water, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds in the low polar or nonpolar solvent by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered for recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 2 tables.

Emission of volatile organic compounds from domestic coal stove with the actual alternation of flaming and smoldering combustion processes.

PubMed

Liu, Chengtang; Zhang, Chenglong; Mu, Yujing; Liu, Junfeng; Zhang, Yuanyuan

2017-02-01

Volatile organic compounds (VOCs) emissions from the chimney of a prevailing domestic stove fuelled with raw bituminous coal were measured under flaming and smoldering combustion processes in a farmer's house. The results indicated that the concentrations of VOCs quickly increased after the coal loading and achieved their peak values in a few minutes. The peak concentrations of the VOCs under the smoldering combustion process were significantly higher than those under the flaming combustion process. Alkanes accounted for the largest proportion (43.05%) under the smoldering combustion, followed by aromatics (28.86%), alkenes (21.91%), carbonyls (5.81%) and acetylene (0.37%). The emission factors of the total VOCs under the smoldering combustion processes (5402.9 ± 2031.8 mg kg -1 ) were nearly one order of magnitude greater than those under the flaming combustion processes (559.2 ± 385.9 mg kg -1 ). Based on the VOCs emission factors obtained in this study and the regional domestic coal consumption, the total VOCs emissions from domestic coal stoves was roughly estimated to be 1.25 × 10 8  kg a -1 in the Beijing-Tianjin-Hebei region. Copyright © 2016 Elsevier Ltd. All rights reserved.

A new sensor for the assessment of personal exposure to volatile organic compounds

NASA Astrophysics Data System (ADS)

Chen, Cheng; Driggs Campbell, Katherine; Negi, Indira; Iglesias, Rodrigo A.; Owens, Patrick; Tao, Nongjian; Tsow, Francis; Forzani, Erica S.

2012-07-01

To improve our understanding of indoor and outdoor personal exposures to common environmental toxicants released into the environment, new technologies that can monitor and quantify the toxicants anytime anywhere are needed. This paper presents a wearable sensor to provide such capabilities. The sensor can communicate with a common smart phone and provides accurate measurement of volatile organic compound concentration at a personal level in real-time, providing environmental toxicants data every three minutes. The sensor has high specificity and sensitivity to aromatic, alkyl, and chlorinated hydrocarbons with a resolution as low as 4 parts-per-billion (ppb), with a detection range of 4 ppb-1000 ppm (parts-per-million). The sensor's performance was validated using Gas Chromatography and Selected Ion Flow Tube - Mass Spectrometry reference methods in a variety of environments and activities with overall accuracy higher than 81% (r2 > 0.9). Field tests examined personal exposure in various scenarios including: indoor and outdoor environments, traffic exposure in different cities which vary from 0 to 50 ppmC (part-per-million carbon from hydrocarbons), and pollutants near the 2010 Deepwater Horizon's oil spill. These field tests not only validated the performance but also demonstrated unprecedented high temporal and spatial toxicant information provided by the new technology.

Missing ozone-induced potential aerosol formation in a suburban deciduous forest

NASA Astrophysics Data System (ADS)

Nakayama, T.; Kuruma, Y.; Matsumi, Y.; Morino, Y.; Sato, K.; Tsurumaru, H.; Ramasamy, S.; Sakamoto, Y.; Kato, S.; Miyazaki, Y.; Mochizuki, T.; Kawamura, K.; Sadanaga, Y.; Nakashima, Y.; Matsuda, K.; Kajii, Y.

2017-12-01

As a new approach to investigating formation processes of secondary organic aerosol (SOA) in the atmosphere, ozone-induced potential aerosol formation was measured in summer at a suburban forest site surrounded by deciduous trees, near Tokyo, Japan. After passage through a reactor containing high concentrations of ozone, increases in total particle volume (average of 1.4 × 109 nm3/cm3, which corresponds to 17% that of pre-existing particles) were observed, especially during daytime. The observed aerosol formations were compared with the results of box model simulations using simultaneously measured concentrations of gaseous and particulate species. According to the model, the relative contributions of isoprene, monoterpene, and aromatic hydrocarbon oxidation to SOA formation in the reactor were 24, 21, and 55%, respectively. However, the model could explain, on average, only ∼40% of the observed particle formation, and large discrepancies between the observations and model were found, especially around noon and in the afternoon when the concentrations of isoprene and oxygenated volatile organic compounds were high. The results suggest a significant contribution of missing (unaccounted-for) SOA formation processes from identified and/or unidentified volatile organic compounds, especially those emitted during daytime. Further efforts should be made to explore and parameterize this missing SOA formation to assist in the improvement of atmospheric chemistry and climate models.

A New Sensor for the Assessment of Personal Exposure to Volatile Organic Compounds

PubMed Central

Chen, Cheng; Campbell, Katherine Driggs; Negi, Indira; Iglesias, Rodrigo A.; Owens, Patrick; Tao, Nongjian; Tsow, Francis; Forzani, Erica

2012-01-01

To improve our understanding of indoor and outdoor personal exposures to common environmental toxicants released into the environment, new technologies that can monitor and quantify the toxicants anytime anywhere are needed. This paper presents a wearable sensor to provide such capabilities. The sensor can communicate with a common smart phone and provides accurate measurement of volatile organic compound concentration at a personal level in real time, providing environmental toxicants data every three minutes. The sensor has high specificity and sensitivity to aromatic, alkyl, and chlorinated hydrocarbons with a resolution as low as 4 parts per billion (ppb), with a detection range of 4 ppb to 1000 ppm (parts per million). The sensor's performance was validated using Gas Chromatography and Selected Ion Flow Tube - Mass Spectrometry reference methods in a variety of environments and activities with overall accuracy higher than 81% (r2 > 0.9). Field tests examined personal exposure in various scenarios including: indoor and outdoor environments, traffic exposure in different cities which vary from 0 to 50 ppmC (part-per-million carbon from hydrocarbons), and pollutants near the 2010 Deepwater Horizon's oil spill. These field tests not only validated the performance but also demonstrated unprecedented high temporal and spatial toxicant information provided by the new technology. PMID:22736952

40 CFR 721.775 - Brominated aromatic com-pound (generic name).

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Requirements as specified in § 721.80 (j) (use as an additive flame retardant for plastics) and (q). (iv... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Brominated aromatic com-pound (generic... Specific Chemical Substances § 721.775 Brominated aromatic com-pound (generic name). (a) Chemical...

40 CFR 721.775 - Brominated aromatic com-pound (generic name).

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Requirements as specified in § 721.80 (j) (use as an additive flame retardant for plastics) and (q). (iv... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Brominated aromatic com-pound (generic... Specific Chemical Substances § 721.775 Brominated aromatic com-pound (generic name). (a) Chemical...

40 CFR 721.775 - Brominated aromatic com-pound (generic name).

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Requirements as specified in § 721.80 (j) (use as an additive flame retardant for plastics) and (q). (iv... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Brominated aromatic com-pound (generic... Specific Chemical Substances § 721.775 Brominated aromatic com-pound (generic name). (a) Chemical...

A model explaining and predicting lamb flavour from the aroma-active chemical compounds released upon grilling light lamb loins.

PubMed

Bueno, Mónica; Campo, M Mar; Cacho, Juan; Ferreira, Vicente; Escudero, Ana

2014-12-01

The objective of the work is to understand the role of the different aroma compounds in the perception of the local "lamb flavour" concept. For this, a set of 70 loins (Longissimus dorsi) from approximately seventy day-old Rasa Aragonesa male lambs were grilled and the aroma-active chemicals released during the grilling process were trapped and analyzed. Carbonyl compounds were derivatizated and determined by GC-NCI-MS, whereas other aromatic compounds were directly analyzed by GC-GC-MS. Odour activity values (OAVs) were calculated using their odour threshold values in air. Lamb flavour could be satisfactory explained by a partial least-squares model (74% explained variance in cross-validation) built by the OAVs of 32 aroma-active chemical compounds. The model demonstrates that the lamb flavour concept is the result of a complex balance. Its intensity critically and positively depends to the levels of volatile fatty acids and several dimethylpyrazines while is negatively influenced by the different alkenals and alkadienals. (E,E)-2,4-decadienal and (E)-2-nonenal showed top OAVs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Device for aqueous detection of nitro-aromatic compounds

DOEpatents

Reagen, W.K.; Schulz, A.L.; Ingram, J.C.; Lancaster, G.D.; Grey, A.E.

1994-04-26

This invention relates to a compact and portable detection apparatus for nitro-aromatic based chemical compounds, such as nitrotoluenes, dinitrotoluenes, and trinitrotoluene (TNT). The apparatus is based upon the use of fiber optics using filtered light. The preferred process of the invention relies upon a reflective chemical sensor and optical and electronic components to monitor a decrease in fluorescence when the nitro-aromatic molecules in aqueous solution combine and react with a fluorescent polycyclic aromatic compound. 4 figures.

Device for aqueous detection of nitro-aromatic compounds

DOEpatents

Reagen, William K.; Schulz, Amber L.; Ingram, Jani C.; Lancaster, Gregory D.; Grey, Alan E.

1994-01-01

This invention relates to a compact and portable detection apparatus for ro-aromatic based chemical compounds, such as nitrotoluenes, dinitrotoluenes, and trinitrotoluene (TNT). The apparatus is based upon the use of fiber optics using filtered light. The preferred process of the invention relies upon a reflective chemical sensor and optical and electronic components to monitor a decrease in fluorescence when the nitro-aromatic molecules in aqueous solution combine and react with a fluorescent polycyclic aromatic compound.

Determination of siloxanes and VOC in landfill gas and sewage gas by canister sampling and GC-MS/AES analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schweigkofler, M.; Niessner, R.

1999-10-15

Biogases such as landfill gas and sewage gas undergo a combustion process which is generating electric energy. Since several trace compounds such as siloxanes (also halogenated and sulfur compounds) are known to cause severe problems to these gas combustion engines, they are of particular interest. In this work, a new technique for sampling, identification, and quantification of siloxanes and volatile organic carbon (VOC) in landfill gas and sewage gas is presented. After sample collection using evacuated stainless steel canisters biogas was analyzed by gas chromatography-mass spectrometry/atomic emission spectroscopy (GC-MS/AES). Using gas canisters, the sampling process was simplified (no vacuum pumpmore » needed), and multiple analysis was possible. The simultaneous application of MSD and AED allowed a rapid screening of silicon compounds in the complex biogases. Individual substances were identified independently both by MSD analysis and by determination of their elemental constitution. Quantification of trace compounds was achieved using a 30 component external standard containing siloxanes, organochlorine and organosulfur compounds, alkanes, terpenes, and aromatic compounds. Precision, linearity, and detection limits have been studied. In real samples, concentrations of silicon containing compounds (trimethylsilanol, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasilioxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane) in the mg/m{sub 3} range have been observed.« less

Flavor and stability of milk proteins.

PubMed

Smith, T J; Campbell, R E; Jo, Y; Drake, M A

2016-06-01

A greater understanding of the nature and source of dried milk protein ingredient flavor(s) is required to characterize flavor stability and identify the sources of flavors. The objective of this study was to characterize the flavor and flavor chemistry of milk protein concentrates (MPC 70, 80, 85), isolates (MPI), acid and rennet caseins, and micellar casein concentrate (MCC) and to determine the effect of storage on flavor and functionality of milk protein concentrates using instrumental and sensory techniques. Spray-dried milk protein ingredients (MPC, MPI, caseins, MCC) were collected in duplicate from 5 commercial suppliers or manufactured at North Carolina State University. Powders were rehydrated and evaluated in duplicate by descriptive sensory analysis. Volatile compounds were extracted by solid phase microextraction followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry. Compounds were identified by comparison of retention indices, odor properties, and mass spectra against reference standards. A subset of samples was selected for further analysis using direct solvent extraction with solvent-assisted flavor extraction, and aroma extract dilution analysis. External standard curves were created to quantify select volatile compounds. Pilot plant manufactured MPC were stored at 3, 25, and 40°C (44% relative humidity). Solubility, furosine, sensory properties, and volatile compound analyses were performed at 0, 1, 3, 6, and 12 mo. Milk proteins and caseins were diverse in flavor and exhibited sweet aromatic and cooked/milky flavors as well as cardboard, brothy, tortilla, soapy, and fatty flavors. Key aroma active compounds in milk proteins and caseins were 2-aminoacetophenone, nonanal, 1-octen-3-one, dimethyl trisulfide, 2-acetyl-1-pyrroline, heptanal, methional, 1-hexen-3-one, hexanal, dimethyl disulfide, butanoic acid, and acetic acid. Stored milk proteins developed animal and burnt sugar flavors over time. Solubility of MPC decreased and furosine concentration increased with storage time and temperature. Solubility of MPC 80 was reduced more than that of MPC 45, but time and temperature adversely affected solubility of both proteins, with storage temperature having the greatest effect. Flavor and shelf stability of milk proteins provide a foundation of knowledge to improve the flavor and shelf-life of milk proteins. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

VOC Reactivity and the Ozone Climate Penalty: Modeled Impacts of Updated Aromatic and Monoterpene Chemistry on the Ozone-temperature Connection

NASA Astrophysics Data System (ADS)

Porter, W. C.; Heald, C. L.; Safieddine, S.

2016-12-01

Rising temperatures associated with global warming can increase concentrations of tropospheric ozone (O3) in many regions worldwide, a correlation often described as the "ozone climate penalty". This effect is driven by a variety of underlying chemical, physical, and biological mechanisms, including temperature-dependent reaction rates, emissions of volatile organic compounds (VOCs) from trees and other plant life, and correlations with other meteorological variables. While many of the most important O3-producing VOCs, such as isoprene, are represented in typical chemical transport models such as GEOS-Chem, others - including aromatics from fires and human activity and monoterpenes from natural sources - are not always included in gas-phase chemistry. Here we examine the impact of increased VOC reactivity on the ozone climate penalty due to a more comprehensive treatment of aromatics and monoterpenes in the chemical transport model GEOS-Chem, finding regional impacts not only on daily O3 levels themselves, but also on the O3/temperature relationship. While many uncertainties related to the emissions and chemistry of these species remain, the impact of their inclusion on both current simulations and future projections indicates their importance towards the overall goal of more accurately modeled surface O3.

Primary emissions and chemical oxidation of volatile organic compounds emitted from laboratory biomass burning sources during the 2016 FIREX FireLab campaign: measurements from a H3O+ chemical ionization mass spectrometer

NASA Astrophysics Data System (ADS)

Coggon, M. M.; Warneke, C.; Koss, A.; Sekimoto, K.; Yuan, B.; Lim, C. Y.; Hagan, D. H.; Kroll, J. H.; Cappa, C. D.; Gilman, J.; Lerner, B. M.; Jimenez, J. L.; Yokelson, R. J.; Roberts, J. M.; De Gouw, J. A.

2017-12-01

Non-methane organic gases (NMOG) emitted by biomass burning constitute a large source of reactive carbon in the atmosphere. Once emitted, these compounds may undergo series of reactions with the OH radical and nitrogen oxides to form secondary organic aerosol (SOA), ozone, or other health-impacting products. The complex emission profile and strong variability of biomass burning NMOG play an important, yet understudied, role in the variability of air quality outcomes such as SOA and ozone. In this study, we summarize measurements of biomass burning volatile organic compounds (VOCs) conducted using a H3O+ chemical ionization mass spectrometer (H3O+-CIMS) during the 2016 FIREX laboratory campaign in Missoula, MT. Specifically, we will present data demonstrating the chemical evolution of biomass burning VOCs artificially aged in a field-deployable photooxidation chamber and an oxidation flow reactor. More than 50 OH-oxidation experiments were conducted with biomass types representing a range of North American fuels. Across many fuel types, VOCs with high SOA and ozone formation potential, such as aromatics and furans, were observed to quickly react with the OH radical while oxidized species were generated. We compare the calculated OH reactivity of the primary emissions to the calculated OH reactivity used in many photochemical models and highlight areas requiring additional research in order to improve model/measurement comparisons.

Plectranthus amboinicus (Lour.) Spreng: Botanical, Phytochemical, Pharmacological and Nutritional Significance.

PubMed

Arumugam, Greetha; Swamy, Mallappa Kumara; Sinniah, Uma Rani

2016-03-30

Plectranthus amboinicus (Lour.) Spreng. is a perennial herb belonging to the family Lamiaceae which occurs naturally throughout the tropics and warm regions of Africa, Asia and Australia. This herb has therapeutic and nutritional properties attributed to its natural phytochemical compounds which are highly valued in the pharmaceutical industry. Besides, it has horticultural properties due to its aromatic nature and essential oil producing capability. It is widely used in folk medicine to treat conditions like cold, asthma, constipation, headache, cough, fever and skin diseases. The leaves of the plant are often eaten raw or used as flavoring agents, or incorporated as ingredients in the preparation of traditional food. The literature survey revealed the occurrence 76 volatiles and 30 non-volatile compounds belonging to different classes of phytochemicals such as monoterpenoids, diterpenoids, triterpenoids, sesquiterpenoids, phenolics, flavonoids, esters, alcohols and aldehydes. Studies have cited numerous pharmacological properties including antimicrobial, antiinflammatory, antitumor, wound healing, anti-epileptic, larvicidal, antioxidant and analgesic activities. Also, it has been found to be effective against respiratory, cardiovascular, oral, skin, digestive and urinary diseases. Yet, scientific validation of many other traditional uses would be appreciated, mainly to discover and authenticate novel bioactive compounds from this herb. This review article provides comprehensive information on the botany, phytochemistry, pharmacology and nutritional importance of P. amboinicus essential oil and its various solvent extracts. This article allows researchers to further explore the further potential of this multi-utility herb for various biomedical applications.

Contamination of ground water, surface water, and soil, and evaluation of selected ground-water pumping alternatives in the Canal Creek area of Aberdeen Proving Ground, Maryland

USGS Publications Warehouse

Lorah, Michelle M.; Clark, Jeffrey S.

1996-01-01

Chemical manufacturing, munitions filling, and other military-support activities have resulted in the contamination of ground water, surface water, and soil in the Canal Creek area of Aberdeen Proving Ground, Maryland. Chlorinated volatile organic compounds, including 1,1,2,2-tetrachloroethane and trichloroethylene, are widespread ground-water contaminants in two aquifers that are composed of unconsolidated sand and gravel. Distribution and fate of chlorinated organic compounds in the ground water has been affected by the movement and dissolution of solvents in their dense immiscible phase and by microbial degradation under anaerobic conditions. Detection of volatile organic contaminants in adjacent surface water indicates that shallow contaminated ground water discharges to surface water. Semivolatile organic compounds, especially polycyclic aromatic hydrocarbons, are the most prevalent organic contaminants in soils. Various trace elements, such as arsenic, cadmium, lead, and zinc, were found in elevated concentrations in ground water, surface water, and soil. Simulations with a ground-water-flow model and particle tracker postprocessor show that, without remedial pumpage, the contaminants will eventually migrate to Canal Creek and Gunpowder River. Simulations indicate that remedial pumpage of 2.0 million gallons per day from existing wells is needed to capture all particles originating in the contaminant plumes. Simulated pumpage from offsite wells screened in a lower confined aquifer does not affect the flow of contaminated ground water in the Canal Creek area.

Biofiltration of odors, toxics and volatile organic compounds from publicly owned treatment works

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webster, T.S.; Devinny, J.S.; Torres, E.M.

1996-12-31

Increasing federal and state regulation has made it necessary to apply air pollution control measures at publicly owned treatment works (POTWs). Traditional control technologies may not be suitable for treating the low and variable contaminant concentrations often found in POTW off-gases. An alternative control technology, biofiltration, was studied. An experiment using bench- and pilot-scale reactors established optimal operating conditions for a full-scale conceptual design. The waste airstream contained ppmv levels of hydrogen sulfide and ppbv levels of specific volatile organic compounds (VOCs). Granular activated carbon (GAC) and yard waste compost (YWG) were tested as possible biofilter media with and withoutmore » pH control. The 16-month field study bench reactors achieved 99% removal of hydrogen sulfide, 53 to 98% removal of aromatic hydrocarbons, 37 to 95% removal of aldehydes and ketones, and 0 to 85% removal of chlorinated compounds. The GAC and YWC pilot reactors removed more than 80% and 65% of the total VOCs at 17 second and 70 second empty bed retention times, respectively. The YWC reactors performed poorly at empty bed retention times of 30 and 45 seconds, removing less than 40% of total VOCs. Declining pH had little negative effect on contaminant removal, suggesting costly control measures may not be necessary. Biofiltration appears to be a feasible alternative to traditional control technologies in treating off-gases from POTWs. 13 refs., 3 figs., 4 tabs.« less

Analysis of volatile compounds produced by 2 strains of Lactococcus lactis isolated from leben (Tunisian fermented milk) using solid-phase microextraction-gas chromatography.

PubMed

Ziadi, M; Wathelet, J P; Marlier, M; Hamdi, M; Thonart, P

2008-08-01

The volatile compounds that characterize Leben during fermentation with 2 Lactococcus lactis strains (SLT6 and SLT10) in flasks, in a 100-L fermentor, and during storage at 4 degrees C, were investigated and compared to those from commercial Leben. Volatile compounds from Leben were concentrated by a Carboxen-PDMS fiber and analyzed by GC-MS. These compounds include acids, alcohols, aldehydes, ketones, sulfur compounds, and hydrocarbons. Commercial Leben presented a poor volatile profile compared to the laboratory-made Leben. The mixed culture of 2 Lactococcus lactis strains resulted in higher volatile compound formation than the single strain culture. The GC volatile profiles of Leben produced in flask and in the 100-L fermentor were similar. Changes in volatile compounds were observed during storage at 4 degrees C. The effect of culture conditions on production of volatiles by SLT6 strain was studied. Aeration (0.1 mL/min) and agitation enhanced the production of diacetyl, acetoin, 3-methylbutanal, and 3-methylbutanol. Fermentation at pH 5 had no effect on volatile production.

Seasonal cycle of indoor-VOCs: comparison of apartments and cities

NASA Astrophysics Data System (ADS)

Schlink, U.; Rehwagen, M.; Damm, M.; Richter, M.; Borte, M.; Herbarth, O.

On the basis of 2103 measurements of volatile organic compounds (VOCs) in indoor air we study the intensity of a seasonal pattern. The data are representative for the German population and were gathered in different cities (Leipzig, München, Köln), in rooms of different type (children's, living, sleeping rooms, and other rooms), and in households of smokers and non-smokers. In addition to the randomly selected different apartments that were sampled each month, we repeatedly measured in a fixed set of 10 apartments. The analysis comprised concentrations of 30 VOCs belonging to the groups of alkanes, cycloalkanes, aromatics, volatile halogenated hydrocarbons, and terpenes. The annual cycle for total VOC concentrations was observed at every site. Seasonality proved to be the most dominant pattern, but it may be modified by further factors, such as the city, the considered VOC component, and the type of the considered room. Highest concentrations occurred during the winter months and amount to approximately three to four times the summer burden. As seasonality may bias the results of health effect studies we fit a seasonal model to our measurements and develop a procedure for seasonal adjustment, which enables to roughly estimate the annual peak concentration utilizing one monthly observation. The seasonal pattern proved to be a general feature of indoor VOC concentrations and, therefore, this adjustment procedure may be generally applicable. For Leipzig, München, and Köln we present site-specific adjustment factors for indoor concentrations of aromatics, terpenes, and alkanes.

Compounds having aromatic rings and side-chain amide-functionality and a method for transporting monovalent anions across biological membranes using the same

DOEpatents

Davis, Jeffery T [College Park, MD; Sidorov, Vladimir [Richmond, VA; Kotch, Frank W [New Phila., PA

2008-04-08

A compound containing at least two aromatic rings covalently bonded together, with each aromatic ring containing at least one oxyacetamide-based side chain, the compound being capable of forming a chloride ion channel across a lipid bilayer, and transporting chloride ion across the lipid bilayer.

Screening of ground water samples for volatile organic compounds using a portable gas chromatograph

USGS Publications Warehouse

Buchmiller, R.C.

1989-01-01

A portable gas chromatograph was used to screen 32 ground water samples for volatile organic compounds. Seven screened samples were positive; four of the seven samples had volatile organic substances identified by second-column confirmation. Four of the seven positive, screened samples also tested positive in laboratory analyses of duplicate samples. No volatile organic compounds were detected in laboratory analyses of samples that headspace screening indicated to be negative. Samples that contained volatile organic compounds, as identified by laboratory analysis, and that contained a volatile organic compound present in a standard of selected compounds were correctly identified by using the portable gas chromatography. Comparisons of screened-sample data with laboratory data indicate the ability to detect selected volatile organic compounds at concentrations of about 1 microgram per liter in the headspace of water samples by use of a portable gas chromatography. -Author

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part I, Deployment, recovery, data interpretation, and quality control and assurance

USGS Publications Warehouse

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part 2, Field tests

USGS Publications Warehouse

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

Aromatic metabolism of filamentous fungi in relation to the presence of aromatic compounds in plant biomass.

PubMed

Mäkelä, Miia R; Marinović, Mila; Nousiainen, Paula; Liwanag, April J M; Benoit, Isabelle; Sipilä, Jussi; Hatakka, Annele; de Vries, Ronald P; Hildén, Kristiina S

2015-01-01

The biological conversion of plant lignocellulose plays an essential role not only in carbon cycling in terrestrial ecosystems but also is an important part of the production of second generation biofuels and biochemicals. The presence of the recalcitrant aromatic polymer lignin is one of the major obstacles in the biofuel/biochemical production process and therefore microbial degradation of lignin is receiving a great deal of attention. Fungi are the main degraders of plant biomass, and in particular the basidiomycete white rot fungi are of major importance in converting plant aromatics due to their ability to degrade lignin. However, the aromatic monomers that are released from lignin and other aromatic compounds of plant biomass are toxic for most fungi already at low levels, and therefore conversion of these compounds to less toxic metabolites is essential for fungi. Although the release of aromatic compounds from plant biomass by fungi has been studied extensively, relatively little attention has been given to the metabolic pathways that convert the resulting aromatic monomers. In this review we provide an overview of the aromatic components of plant biomass, and their release and conversion by fungi. Finally, we will summarize the applications of fungal systems related to plant aromatics. Copyright © 2015 Elsevier Inc. All rights reserved.

Electron beam technology for multipollutant emissions control from heavy fuel oil-fired boiler.

PubMed

Chmielewski, Andrzej G; Ostapczuk, Anna; Licki, Janusz

2010-08-01

The electron beam treatment technology for purification of exhaust gases from the burning of heavy fuel oil (HFO) mazout with sulfur content approximately 3 wt % was tested at the Institute of Nuclear Chemistry and Technology laboratory plant. The parametric study was conducted to determine the sulfur dioxide (SO2), oxides of nitrogen (NO(x)), and polycyclic aromatic hydrocarbon (PAH) removal efficiency as a function of temperature and humidity of irradiated gases, absorbed irradiation dose, and ammonia stoichiometry process parameters. In the test performed under optimal conditions with an irradiation dose of 12.4 kGy, simultaneous removal efficiencies of approximately 98% for SO2, and 80% for NO(x) were recorded. The simultaneous decrease of PAH and one-ringed aromatic hydrocarbon (benzene, toluene, and xylenes [BTX]) concentrations was observed in the irradiated flue gas. Overall removal efficiencies of approximately 42% for PAHs and 86% for BTXs were achieved with an irradiation dose 5.3 kGy. The decomposition ratio of these compounds increased with an increase of absorbed dose. The decrease of PAH and BTX concentrations was followed by the increase of oxygen-containing aromatic hydrocarbon concentrations. The PAH and BTX decomposition process was initialized through the reaction with hydroxyl radicals that formed in the electron beam irradiated flue gas. Their decomposition process is based on similar principles as the primary reaction concerning SO2 and NO(x) removal; that is, free radicals attack organic compound chains or rings, causing volatile organic compound decomposition. Thus, the electron beam flue gas treatment (EBFGT) technology ensures simultaneous removal of acid (SO2 and NO(x)) and organic (PAH and BTX) pollutants from flue gas emitted from burning of HFO. This technology is a multipollutant emission control technology that can be applied for treatment of flue gas emitted from coal-, lignite-, and HFO-fired boilers. Other thermal processes such as metallurgy and municipal waste incinerators are potential candidates for this technology application.

Retardation effect of nitrogen compounds and condensed aromatics on shale oil catalytic cracking processing and their characterization.

PubMed

Li, Nan; Chen, Chen; Wang, Bin; Li, Shaojie; Yang, Chaohe; Chen, Xiaobo

Untreated shale oil, shale oil treated with HCl aqueous solution and shale oil treated with HCl and furfural were used to do comparative experiments in fixed bed reactors. Nitrogen compounds and condensed aromatics extracted by HCl and furfural were characterized by electrospray ionization Fourier transform cyclotron resonance mass spectrometry and gas chromatography and mass spectrometry, respectively. Compared with untreated shale oil, the conversion and yield of liquid products increased considerably after removing basic nitrogen compounds by HCl extraction. Furthermore, after removing nitrogen compounds and condensed aromatics by both HCl and furfural, the conversion and yield of liquid products further increased. In addition, N 1 class species are predominant in both basic and non-basic nitrogen compounds, and they are probably indole, carbazole, cycloalkyl-carbazole, pyridine and cycloalkyl-pyridine. As for the condensed aromatics, most of them possess aromatic rings with two to three rings and zero to four carbon atom.

Formation of highly oxygenated low-volatility products from cresol oxidation

NASA Astrophysics Data System (ADS)

Schwantes, Rebecca H.; Schilling, Katherine A.; McVay, Renee C.; Lignell, Hanna; Coggon, Matthew M.; Zhang, Xuan; Wennberg, Paul O.; Seinfeld, John H.

2017-03-01

Hydroxyl radical (OH) oxidation of toluene produces ring-retaining products: cresol and benzaldehyde, and ring-opening products: bicyclic intermediate compounds and epoxides. Here, first- and later-generation OH oxidation products from cresol and benzaldehyde are identified in laboratory chamber experiments. For benzaldehyde, first-generation ring-retaining products are identified, but later-generation products are not detected. For cresol, low-volatility (saturation mass concentration, C* ˜ 3.5 × 104 - 7.7 × 10-3 µg m-3), first- and later-generation ring-retaining products are identified. Subsequent OH addition to the aromatic ring of o-cresol leads to compounds such as hydroxy, dihydroxy, and trihydroxy methyl benzoquinones and dihydroxy, trihydroxy, tetrahydroxy, and pentahydroxy toluenes. These products are detected in the gas phase by chemical ionization mass spectrometry (CIMS) and in the particle phase using offline direct analysis in real-time mass spectrometry (DART-MS). Our data suggest that the yield of trihydroxy toluene from dihydroxy toluene is substantial. While an exact yield cannot be reported as authentic standards are unavailable, we find that a yield for trihydroxy toluene from dihydroxy toluene of ˜ 0.7 (equal to the reported yield of dihydroxy toluene from o-cresol; Olariu et al., 2002) is consistent with experimental results for o-cresol oxidation under low-NO conditions. These results suggest that even though the cresol pathway accounts for only ˜ 20 % of the oxidation products of toluene, it is the source of a significant fraction (˜ 20-40 %) of toluene secondary organic aerosol (SOA) due to the formation of low-volatility products.

PERFLUORINATED AROMATIC COMPOUNDS

DTIC Science & Technology

decafluorodiphenylamine, 3,3’,4,4’-tetra substituted- hexafluorobiphenyls, tetrafluororesorcinol, perfluoroaromatic thioethers, and dithiols. These...and other perfluorinated aromatic compounds are the intermediates employed in the synthesis of perfluorinated model compounds and polymers.

Bacterial Degradation of Aromatic Compounds

PubMed Central

Seo, Jong-Su; Keum, Young-Soo; Li, Qing X.

2009-01-01

Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms. PMID:19440284

Evidence and quantitation of aromatic organosulfates in ambient aerosols in Lahore, Pakistan

NASA Astrophysics Data System (ADS)

Kundu, S.; Quraishi, T. A.; Yu, G.; Suarez, C.; Keutsch, F. N.; Stone, E. A.

2013-05-01

Organosulfates are important components of atmospheric organic aerosols, yet their structures, abundances, sources and formation processes are not adequately understood. This study presents the identification and quantitation of benzyl sulfate in atmospheric aerosols, which is the first confirmed atmospheric organosulfate with aromatic carbon backbone. Benzyl sulfate was identified and quantified in fine particulate matter (PM2.5) collected in Lahore, Pakistan, during 2007-2008. An authentic standard of benzyl sulfate was synthesized, standardized, and identified in atmospheric aerosols with quadrupole time-of-flight (Q-ToF) mass spectrometry (MS). Benzyl sulfate was quantified in aerosol samples using ultra performance liquid chromatography (UPLC) coupled to negative electrospray ionization triple quadrupole (TQ) MS. The highest benzyl sulfate concentrations were recorded in November and January 2007 (0.50 ± 0.11 ng m-3) whereas the lowest concentration was observed in July (0.05 ± 0.02 ng m-3). To evaluate matrix effects, benzyl sulfate concentrations were determined using external calibration and the method of standard addition; comparable concentrations were detected by the two methods, which ruled out significant matrix effects in benzyl sulfate quantitation. Three additional organosulfates with m/z 187, 201 and 215 were qualitatively identified as aromatic organosulfates with additional methyl substituents by high-resolution mass measurements and tandem MS. The observed aromatic organosulfates form a homologous series analogous to toluene, xylene, and trimethylbenzene, which are abundant anthropogenic volatile organic compounds (VOC), suggesting that aromatic organosulfates may be formed by secondary reactions. However, stronger statistical correlations of benzyl sulfate with combustion tracers (EC and levoglucosan) than with secondary tracers (SO42- and α-pinene-derived nitrooxy organosulfates) suggest that aromatic organosulfates may be emitted from the combustion sources or their subsequent atmospheric processing. Further studies are needed to elucidate the sources and formation pathways of aromatic organosulfates in the atmosphere.

Bond cleavage of lignin model compounds into aromatic monomers using supported metal catalysts in supercritical water

PubMed Central

Yamaguchi, Aritomo; Mimura, Naoki; Shirai, Masayuki; Sato, Osamu

2017-01-01

More efficient use of lignin carbon is necessary for carbon-efficient utilization of lignocellulosic biomass. Conversion of lignin into valuable aromatic compounds requires the cleavage of C–O ether bonds and C–C bonds between lignin monomer units. The catalytic cleavage of C–O bonds is still challenging, and cleavage of C–C bonds is even more difficult. Here, we report cleavage of the aromatic C–O bonds in lignin model compounds using supported metal catalysts in supercritical water without adding hydrogen gas and without causing hydrogenation of the aromatic rings. The cleavage of the C–C bond in bibenzyl was also achieved with Rh/C as a catalyst. Use of this technique may greatly facilitate the conversion of lignin into valuable aromatic compounds. PMID:28387304

Three-dimensional aromatic networks.

PubMed

Toyota, Shinji; Iwanaga, Tetsuo

2014-01-01

Three-dimensional (3D) networks consisting of aromatic units and linkers are reviewed from various aspects. To understand principles for the construction of such compounds, we generalize the roles of building units, the synthetic approaches, and the classification of networks. As fundamental compounds, cyclophanes with large aromatic units and aromatic macrocycles with linear acetylene linkers are highlighted in terms of transannular interactions between aromatic units, conformational preference, and resolution of chiral derivatives. Polycyclic cage compounds are constructed from building units by linkages via covalent bonds, metal-coordination bonds, or hydrogen bonds. Large cage networks often include a wide range of guest species in their cavity to afford novel inclusion compounds. Topological isomers consisting of two or more macrocycles are formed by cyclization of preorganized species. Some complicated topological networks are constructed by self-assembly of simple building units.

Urban organic aerosols measured by single particle mass spectrometry in the megacity of London

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Harrison, R. M.

2011-02-01

During the month of October 2006, as part of the REPARTEE-I experiment (Regent's Park and Tower Environmental Experiment) an Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) was deployed at an urban background location in the city of London, UK. Fifteen particle types were classified, some of which were accompanied by Aerosol Mass Spectrometer (AMS) quantitative aerosol mass loading measurements (Dall'Osto et al., 2009a, b). In this manuscript the origins and properties of four particle types associated with locally generated aerosols, independent of the air mass type advected into London, are examined. One particle type, originating from lubricating oil (referred to as Ca-EC), was associated with morning rush hour traffic emissions. A second particle type, composed of both inorganic and organic species (called Na-EC-OC), was found enhanced in particle number concentration during evening time periods, and is likely to originate from a source operating at this time of day, or more probably from condensation of semi-volatile species, and contains both primary and secondary components. A third class, internally mixed with organic carbon and sulphate (called OC), was found to spike both in the morning and evenings. The fourth class (SOA-PAH) exhibited maximum frequency during the warmest part of the day, and a number of factors point towards secondary production from traffic-related volatile aromatic compounds. Single particle mass spectra of this particle type showed an oxidized polycyclic aromatic compound signature. Finally, a comparison of ATOFMS particle class data is made with factors obtained by Positive Matrix Factorization from AMS data.. Both the Ca-EC and OC particle types correlate with the AMS HOA primary organic fraction (R2 = 0.65 and 0.50 respectively), and Na-EC-OC, but not SOA-PAH, which correlates weakly with the AMS OOA secondary organic aerosol factor (R2 = 0.35). A detailed analysis was conducted to identify ATOFMS particle type(s) representative of the AMS COA cooking aerosol factor, but no convincing associations were found.

Influence of physicochemical parameters and high pressure processing on the volatile compounds of Serrano dry-cured ham after prolonged refrigerated storage.

PubMed

Martínez-Onandi, N; Rivas-Cañedo, A; Picon, A; Nuñez, M

2016-12-01

One hundred and three volatile compounds were detected by solid-phase microextraction followed by gas chromatography-mass spectrometry in 30 ripened Serrano dry-cured hams, submitted or not to high pressure processing (HPP) and afterwards held for 5months at 4°C. The effect of ham physicochemical parameters and HPP (600MPa for 6min) on volatile compounds was assessed. Physicochemical parameters primarily affected the levels of acids, alcohols, alkanes, esters, benzene compounds, sulfur compounds and some miscellaneous compounds. Intramuscular fat content was the physicochemical parameter with the most pronounced effect on the volatile fraction of untreated Serrano ham after refrigerated storage, influencing the levels of 38 volatile compounds while aw, salt content and salt-in-lean ratio respectively influenced the levels of 4, 4 and 5 volatile compounds. HPP treatment affected 21 volatile compounds, resulting in higher levels of alkanes and ketones and lower levels of esters and secondary alcohols, what might affect Serrano ham odor and aroma after 5months of refrigerated storage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

PubMed

Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

2017-04-01

Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Produced water ponds are an important source of aromatics and alcohols in Rocky Mountain oil and gas basins

NASA Astrophysics Data System (ADS)

Lyman, S. N.

2017-12-01

Most of the water extracted with oil and natural gas (i.e., produced water) is disposed of by injection into the subsurface. In the arid western United States, however, a significant portion of produced water is discharged in ponds for evaporative disposal, and produced water is often stored in open ponds prior to subsurface injection. Even though they are common in the West (Utah's Uinta Basin has almost 200 ha), produced water ponds have been excluded from oil and gas emissions inventories because little information about their emission rates and speciation is available. We used flux chambers and inverse plume modeling to measure emissions of methane, C2-C11 hydrocarbons, light alcohols, carbonyls, and carbon dioxide from oil and gas produced water storage and disposal ponds in the Uinta Basin and the Upper Green River Basin, Wyoming, during 2013-2017. Methanol was the most abundant organic compound in produced water (91 ± 2% of the total volatile organic concentration; mean ± 95% confidence interval) but accounted for only 25 ± 30% of total organic compound emissions from produced water ponds. Non-methane hydrocarbons, especially C6-C9 alkanes and aromatics, accounted for the majority of emitted organics. We were able to predict emissions of individual compounds based on water concentrations, but only to within an order of magnitude. The speciation and magnitude of emissions varied strongly across facilities and was influenced by water age, the presence or absence of oil sheens, and with meteorological conditions (especially ice cover). Flux chamber measurements were lower than estimates from inverse modeling techniques.Based on our flux chamber measurements, we estimate that produced water ponds are responsible for between 3 and 9% of all non-methane organic compound emissions in the Uinta Basin (or as much as 18% if we rely on our inverse modeling results). Emissions from produced water ponds contain little methane and are more reactive (i.e., they have higher maximum incremental reactivity) than typical oil and gas-related emissions. Produced water ponds emit about 11% and 28%, respectively, of all aromatics and alcohols from the Uinta Basin oil and gas industry.

On-road traffic emissions of polycyclic aromatic hydrocarbons and their oxy- and nitro- derivative compounds measured in road tunnel environments.

PubMed

Keyte, Ian J; Albinet, Alexandre; Harrison, Roy M

2016-10-01

Vehicular emissions are a key source of polycyclic aromatic compounds (PACs), including polycyclic aromatic hydrocarbons (PAHs) and their oxygenated (OPAH) and nitrated (NPAH) derivatives, in the urban environment. Road tunnels are a useful environment for the characterisation of on-road vehicular emissions, providing a realistic traffic fleet and a lack of direct sunlight, chemical reactivity and non-traffic sources. In the present investigation the concentrations of selected PAHs, OPAHs and NPAHs have been measured in the Parc des Princes Tunnel in Paris (PdPT, France), and at the Queensway Road Tunnel and an urban background site in Birmingham (QT, U.K). A higher proportion of semi-volatile (3-4 ring) PAH, OPAH and NPAH compounds are associated with the particulate phase compared with samples from the ambient environment. A large (~85%) decline in total PAH concentrations is observed between 1992 and 2012 measurements in QT. This is attributed primarily to the introduction of catalytic converters in the U.K as well as increasingly stringent EU vehicle emissions legislation. In contrast, NPAH concentrations measured in 2012 are similar to those measured in 1996. This observation, in addition to an increased proportion of (Phe+Flt+Pyr) in the observed PAH burden in the tunnel, is attributed to the increased number of diesel passenger vehicles in the U.K during this period. Except for OPAHs, comparable PAH and NPAH concentrations are observed in both investigated tunnels (QT and PdP). Significant differences are shown for specific substances between PAC chemical profiles in relation with the national traffic fleet differences (33% diesel passenger cars in U.K. vs 69% in France and up to 80% taking into account all vehicle categories). The dominating and sole contribution of 1-Nitropyrene observed in the PdPT NPAH profile strengthens the promising use of this compound as a diesel exhaust marker for PM source apportionment studies. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.

Urban organic aerosols measured by single particle mass spectrometry in the megacity of London

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Harrison, R. M.

2012-05-01

During the month of October 2006, as part of the REPARTEE-I experiment (Regent's Park and Tower Environmental Experiment) an Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) was deployed at an urban background location in the city of London, UK. Fifteen particle types were classified, some of which were already discussed (Dall'Osto et al., 2009a,b; Harrison et al., 2012). In this manuscript the origins and properties of four unreported particle types postulated to be due to locally generated aerosols, independent of the air mass type advected into London, are examined. One particle type, originating from lubricating oil (referred to as Ca-EC), was associated with morning rush hour traffic emissions. A second particle type, composed of both inorganic and organic species (called Na-EC-OC), was found enhanced in particle number concentration during evening time periods, and is likely to originate from a source operating at this time of day, or more probably from condensation of semi-volatile species. A third class, internally mixed with organic carbon and sulphate (called OC), was found to spike both in the morning and evenings although it could not unambiguously associated with a specific source or atmospheric process. The fourth class (Secondary Organic Aerosols - Polycyclic Aromatic Hydrocarbon; SOA-PAH) exhibited maximum frequency during the warmest part of the day, and a number of factors point towards secondary aerosol production from traffic-related volatile aromatic compounds. Single particle mass spectra of this particle type showed an oxidized polycyclic aromatic compound signature. A comparison of ATOFMS particle class data is then made with factors obtained by Positive Matrix Factorization and PAH signatures obtained from Aerosol Mass Spectrometer (AMS) data (Allan et al., 2010). Both the Ca-EC and OC particle types correlate with primary Hydrocarbon-like Organic Aerosol (HOA, R2 = 0.65 and 0.50 respectively), and Na-EC-OC correlates weakly with the AMS secondary Oxygenated Organic Aerosol (OOA), (R2 = 0.35). Cluster SOA-PAH was found not to correlate with any AMS signal. A detailed analysis was conducted to identify ATOFMS particle type(s) representative of the AMS cooking aerosol factor (COA), but no convincing associations were found. The combined ATOFMS and AMS results of this REPARTEE study do not always provide an entirely coherent interpretation.

Characterization by volatile compounds of microbial deep spoilage in Iberian dry-cured ham.

PubMed

Martín, Alberto; Benito, María J; Aranda, Emilio; Ruiz-Moyano, Santiago; Córdoba, Juan J; Córdoba, María G

2010-08-01

In the present study, volatile compounds of spoiled dry-cured Iberian ham with deep spoilage or "bone taint" were analyzed and correlated with level of spoilage and the microorganisms detected. Volatile compounds extracted by a solid phase micro-extraction technique were assayed by gas chromatography/mass spectrometry. The spoiled hams were evaluated sensorially, and the correlations among volatile compounds, spoilage level, and microbial counts were studied. The spoiled hams had higher concentrations of hydrocarbons, alcohols, acids, esters, pyrazines, sulfur compounds, and other minor volatile compounds than unspoiled hams. The sensorial analysis showed that the spoilage level of hams correlated with several volatile compounds, most of them associated with Gram-positive catalase positive cocci and Enterobacteriaceae counts. Cyclic compounds such as cyclohexanone, some ethers, and pyrazines should be considered as indicators to monitor incipient microbial deep spoilage in the elaboration of this meat product.

Seasonal variation of the essential oil from two Brazilian native Aldama La Llave (Asteraceae) species.

PubMed

Oliveira, Tuane S DE; Bombo, Aline B; Oliveira, Adriana S S DE; Garcia, Vera L; Appezzato-DA-Glória, Beatriz

2016-01-01

Aldama arenaria and A. robusta are morphologically similar aromatic species that have seasonal development. The yield and chemical composition of essential oils from aerial and underground vegetative organs of these species were compared to verify the production of volatile metabolites in flowering and dormant phases of development and to identify if there are unique compounds for either species. The major compound in the essential oils from A. arenaria leaves was palustrol (16.22%) and for aerial stems was limonene (15.3%), whereas limonene (11.16%) and α-pinene (19.64%) were the major compounds for leaves and aerial stems from A. robusta, respectively. The major compound for the underground organs was α-pinene, in both species and phenological stages. High amounts of diterpenes were found especially for A. arenaria essential oils. Each analyzed species presented unique compounds, which can provide a characteristic chemical profile for both species helping to solve their taxonomic problems. This study characterized for the first time the yield and essential oil composition of A. arenaria and A. robusta, which have medicinal potential, and some of the compounds in their essential oils are unique to each one and may be useful in helping the correct identification of them.

Systematic study of the contamination of wastewater treatment plant effluents by organic priority compounds in Almeria province (SE Spain).

PubMed

Barco-Bonilla, Nieves; Romero-González, Roberto; Plaza-Bolaños, Patricia; Martínez Vidal, José L; Garrido Frenich, Antonia

2013-03-01

The occurrence of priority organic pollutants in wastewater (WW) effluents was evaluated in a semi-arid area, characterized by a high agricultural and tourism activity, as Almeria province (Southeastern Spain). Twelve wastewater treatment plants (WWTPs) were sampled in three campaigns during 2011, obtaining a total of 33 WW samples, monitoring 226 compounds, including pesticides, polycyclic aromatic hydrocarbons (PAHs), phenolic compounds and volatile organic compounds (VOCs). Certain banned organochlorine pesticides such as aldrin, pentachlorobenzene, o,p'-DDD and endosulfan lactone were found, and the most frequently detected pesticides were herbicides (diuron, triazines). PAHs and VOCs were also detected, noting that some of these pollutants were ubiquitous. Regarding phenolic compounds, 4-tertoctylphenol was found in all the WW samples at high concentration levels (up to 89.7 μg/L). Furthermore, it was observed that WW effluent samples were less contaminated in the second and third sampling periods, which corresponded to dry season. This evaluation revealed that despite the WW was treated in the WWTP, organic contaminants are still being detected in WW effluents and therefore they are released into the environment. Finally the risk of environmental threat due to the presence of some compounds in WWTP effluents, especially concerning 4-tertoctylphenol must be indicated. Copyright © 2013 Elsevier B.V. All rights reserved.

Language of plants: Where is the word?

PubMed

Šimpraga, Maja; Takabayashi, Junji; Holopainen, Jarmo K

2016-04-01

Plants emit biogenic volatile organic compounds (BVOCs) causing transcriptomic, metabolomic and behavioral responses in receiver organisms. Volatiles involved in such responses are often called "plant language". Arthropods having sensitive chemoreceptors can recognize language released by plants. Insect herbivores, pollinators and natural enemies respond to composition of volatiles from plants with specialized receptors responding to different types of compounds. In contrast, the mechanism of how plants "hear" volatiles has remained obscured. In a plant-plant communication, several individually emitted compounds are known to prime defense response in receiver plants with a specific manner according to the chemical structure of each volatile compound. Further, composition and ratio of volatile compounds in the plant-released plume is important in plant-insect and plant-plant interactions mediated by plant volatiles. Studies on volatile-mediated plant-plant signaling indicate that the signaling distances are rather short, usually not longer than one meter. Volatile communication from plants to insects such as pollinators could be across distances of hundreds of meters. As many of the herbivore induced VOCs have rather short atmospheric life times, we suggest that in long-distant communications with plant volatiles, reaction products in the original emitted compounds may have additional information value of the distance to emission source together with the original plant-emitted compounds. © 2015 Institute of Botany, Chinese Academy of Sciences.

75 FR 60013 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Control of Volatile...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-29

... Promulgation of Air Quality Implementation Plans; Maryland; Control of Volatile Organic Compounds Emissions... Maryland's Volatile Organic Compounds from Specific Processes Regulation. Maryland has adopted standards... (RACT) requirements for sources of volatile organic compounds (VOCs) covered by control techniques...

Mass spectral analysis of long chain alkyl aromatic compounds synthesized from alpha-olefin alkylation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, M.T.; Hudson, J.D.

1994-12-31

Long chain alkyl aromatic compounds are important petrochemicals with many applications. They are generally synthesized by alkylating the corresponding aromatic nucleus. In this report, the authors will describe the mass spectral fragmentation of alkylphenols and alkylsalicylates.

Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system.

PubMed

Cayot, Nathalie; Lafarge, Céline; Bou-Maroun, Elias; Cayot, Philippe

2016-07-22

Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds with different hydrophobicity are used. High extraction yields were positively correlated with high boiling points and high Log Kow values of volatile compounds. Mixtures of solvents such as azeotrope propan-2-one/cyclopentane, azeotrope ethyl acetate/ethanol, and mixture ethyl acetate/ethanol (3:1, v/v) gave higher extraction yields than those obtained with dichloromethane. Copyright © 2016 Elsevier B.V. All rights reserved.

Consumer palatability scores and volatile beef flavor compounds of five USDA quality grades and four muscles.

PubMed

Legako, J F; Brooks, J C; O'Quinn, T G; Hagan, T D J; Polkinghorne, R; Farmer, L J; Miller, M F

2015-02-01

Proximate data, consumer palatability scores and volatile compounds were investigated for four beef muscles (Longissimus lumborum, Psoas major, Semimembranosus and Gluteus medius) and five USDA quality grades(Prime, Upper 2/3 Choice, Low Choice, Select, and Standard). Quality grade did not directly affect consumer scores or volatiles but interactions (P < 0.05) between muscle and grade were determined. Consumer scores and volatiles differed (P < 0.05) between muscles. Consumers scored Psoas major highest for tenderness, juiciness, flavor liking and overall liking, followed by Longissimus lumborum, Gluteus medius, and Semimembranosus (P < 0.05). Principal component analysis revealed clustering of compound classes, formed by related mechanisms. Volatile n-aldehydes were inversely related to percent fat. Increases in lipid oxidation compounds were associated with Gluteus medius and Semimembranosus, while greater quantities of sulfur-containing compounds were associated with Psoas major. Relationships between palatability scores and volatile compound classes suggest that differences in the pattern of volatile compounds may play a valuable role in explaining consumer liking.

Development of volatile compounds during the manufacture of dry-cured "lacón," a Spanish traditional meat product.

PubMed

Purriños, Laura; Bermúdez, Roberto; Franco, Daniel; Carballo, Javier; Lorenzo, José M

2011-01-01

Volatile compounds were determined throughout the manufacture of dry-cured "lacón," a traditional dry-salted, and ripened meat product made in the north-west of Spain from the foreleg of the pig following a similar process to that of dry-cured ham. Volatiles were extracted by a purge-and-trap method and analyzed by gas chromatographic/mass spectrometry. One hundred and two volatile compounds were identified. In raw material, only 34 volatile compounds were found and at very low levels. The number of volatile compounds increased during processing. The substances identified belonged to several chemical classes: aldehydes (23), alcohols (9), ketones (15), hydrocarbons (37), esters (4), acids (3), furans (4), sulphur compounds (1), chloride compounds (1), and other compounds (4). Results indicated that the most abundant chemical family in flavor at the end of the manufacturing process was aldehydes, followed by hydrocarbons and ketones. Lipids were the most important precursor of flavor compounds of dry-cured "lacón."

Organics, Isotopes, and Volatiles in Gale Crater Sedimentary Rocks

NASA Astrophysics Data System (ADS)

Mahaffy, P. R.

2016-12-01

Solid samples analyzed by the Curiosity rover on the long traverse from the Gale crater floor to the flanks of Mt. Sharp spread a range of environments from fluvial to lacustrine to eolian, and span 100 m of stratigraphic thickness. The diverse chemical and isotopic composition of organic compounds and inorganic volatiles revealed in these samples analyzed over a period of more than 2 Mars years is described with an emphasis on the search for organics, the chemical environments and physical-chemical processes that respectively preserve or destroy organics, and unexpectedly large variations in H, S, and Cl isotopes. In addition to a set of aromatic and aliphatic chorine containing organic compounds thermally released from the Cumberland mudstone drilled early in the mission compounds [Freissinet et al., 2015], additional S-containing organics have been identified in the Mojave drill sample in the Pahrump Hills section that was characterized in detail over a 5 month period. This set of S and Cl containing compounds is definitively identified by gas chromatograph mass spectrometer (GCMS) analyses. In addition, fragments of other organic compounds are evident in the evolved gas analysis (EGA) experiments implemented by the Sample Analysis at Mars (SAM) instrument and utilization of SAM's derivatization agent has revealed the presence of high molecular weight compounds. Two factors complicate the search for organic compounds preserved from ancient Mars. First the nearly ubiquitous oxychlorine compounds such as perchlorates decompose on heating in the SAM ovens in the EGA experiments and there is evidence that the hot O2 released combusts organic compounds to produce CO2. Secondly, the cosmic radiation that penetrates through the thin Mars atmosphere meters into the surface transforms near surface organic compounds over time. Fortunately, the SAM mass spectrometer can measure spallogenic (3He and 21Ne) and neutron-capture (36Ar) noble gases to secure an estimate of the duration of radiation exposure. Measurement protocols developed to work around both of these limitations will be discussed. C. Freissinet et al, JGR (2015) 120(3), 495-514.

[Concentration and change of VOCs in summer and autumn in Tangshan].

PubMed

Sun, Jie; Wang, Yue-si; Wu, Fang-kun; Qiu, Jun

2010-07-01

In order to study the potential impact of volatile organic compounds (VOCs) in summer and autumn on region ozone, ambient concentrations and changes of VOCs were analyzed at Tangshan from June to September 2007 and 2008, by using the method of two-step-concentration-gas spectrometry/mass (CCD-GC/MS). The average concentration in Tangshan was 163.5 x 10(-9) C. The major components were alkanes, aromatics, alkenes and halogen hydrocarbons which accounted for 45.9%, 29.9%, 5.9% and 18.9% respectively. The average concentration decreased 51.9% compare with 2007 (340.4 x 10(-9) C), confine gas stations is the main reason of the decline of alkyl, the large decline is aromatic hydrocarbons, 67%, which has the most potential impact of ozone formation, and dichlorobenzene in industrial emissions has increased. The concentrations of VOCs in Tangshan were lower 8% than that of Beijing during the same period in 2008. The changes of VOCs during 2008 Beijing Olympic show that in addition to traffic source industrial emissions is also an important source of atmospheric pollution.

Bacterial succession and the dynamics of volatile compounds during the fermentation of Chinese rice wine from Shaoxing region.

PubMed

Liu, Shuang Ping; Mao, Jian; Liu, Yun Ya; Meng, Xiang Yong; Ji, Zhong Wei; Zhou, Zhi Lei; Ai-lati, Aisikaer

2015-12-01

Shaoxing rice wine is one of the most typical representatives of Chinese rice wine. It is brewed under non-sterile condition with various microorganism growing at the same time and forms a special flavor. The aims of this study was to monitor the bacterial succession by MiSeq pyrosequencing and the volatile compound dynamics by HS-SPME/GC–MS during brewing process. Moreover, the volatile compounds and bacterial community were analyzed by partial least squares regression to evaluate the effect of bacteria on volatile compounds formation. The results showed that there were ten dominating genera during Shaoxing rice wine fermentation process. Ten genera, Bacillus, Leuconostoc, Lactococcus, Weissella, Thermoactinomyces, Pseudomonas, Saccharopolyspora, Staphylococcus, Enterobacter and Lactobacillus, were identified as the main bacteria. The Bacillus and Lactobacillus dominated the Chinese rice wine ecosystems. In addition, a total of 64 volatile compounds were identified, mainly esters, alcohols, carbonyl compound and phenols. Pseudomonas were involved in synthesis of a wide variety of volatile compounds. Thermoactinomyces, Bacillus and Lactococcus also played critical roles in the formation of volatile compounds.

Water-quality assessment of south-central Texas: Occurrence and distribution of volatile organic compounds in surface water and ground water, 1983-94, and implications for future monitoring

USGS Publications Warehouse

Ging, P.B.; Judd, L.J.; Wynn, K.H.

1997-01-01

The study area of the South-Central Texas study unit of the National Water-Quality Assessment Program comprises the Edwards aquifer in the San Antonio region and its catchment area. The first phase of the assessment includes evaluation of existing water-quality data for surface water and ground water, including volatile organic compounds, to determine the scope of planned monitoring. Most analyses of volatile organic compounds in surface water are from the National Pollutant Discharge Elimination System sites in San Antonio, Texas. Nine volatile organic compounds were detected at the six sites. The three compounds with the most detections at National Pollutant Discharge Elimination System sites are 1,2,4-trimethylbenzene, toluene, and xylene. Analysis of volatile organic compounds in ground water was limited to Edwards aquifer wells. Twenty-eight volatile organic compounds were detected in samples from 89 wells. The five most commonly detected compounds in samples from wells, in descending order, are tetrachloroethene, trichloroethene, bromoform, chloroform, and dibromochloromethane. Detections of volatile organic compounds in surface water and ground water within the South-Central Texas study area are limited to site-specific sources associated with development; therefore, planned monitoring for possible detections of volatile organic compounds as part of the National Water-Quality Assessment Program will emphasize areas of expanding population and development. Monitoring of volatile organic compounds is planned at National Pollutant Discharge Elimination System sites, at basic fixed surface-water sites, and in the ground-water study-unit surveys.

Vertical characteristics of VOCs in the lower troposphere over the North China Plain during pollution periods.

PubMed

Sun, Jie; Wang, Yuesi; Wu, Fangkun; Tang, Guiqian; Wang, Lili; Wang, Yinghong; Yang, Yuan

2018-05-01

In recent years, photochemical smog and gray haze-fog have frequently appeared over northern China. To determine the spatial distribution of volatile organic compounds (VOC) during a pollution period, tethered balloon flights were conducted over a suburban site on the North China Plain. Statistical analysis showed that the VOCs concentrations peaked at the surface, and decreased with altitude. A rapid decrease appeared from the surface to 400 m, with concnetrations of alkanes, alkenes, aromatics and halocarbons decreasing by 48.0%, 53.3%, 43.3% and 51.1%, respectively. At heights in the range of 500-1000 m, alkenes concnetrations decline by 40.2%; alkanes and halocarbons concnetrations only decreased by 24.8% and 6.4%, respectively; and aromatics increased slightly by 5.5%. High concentrations VOCs covered a higher range of height (400 m) on heavy pollution days due to lacking of diffusion power. The VOCs concentrations decreased by 50% at 200 m on light pollution days. The transport of air mass affected the composition and concentration of high-altitude VOCs, especially on lightly polluted days. These air masses originated in areas with abundant traffic and combustion sources. Reactive aromatics (k OH >20,000 ppm -1  min -1 and k OH <20,000 ppm -1  min -1 ) were the main contributor to the ozone formation, accounting for 37%, on the surface on light pollution days. The contribution increased to 52% with pollution aggravated, and increased to 64% with height. The contributions of reactive aromatics were influenced by the degree of air mass aging. Under the umbrella of aging air mass, the contribution of reactive aromatics increased with height. Copyright © 2017. Published by Elsevier Ltd.

Data compilation for assessing sediment and toxic chemical loads from the Green River to the lower Duwamish Waterway, Washington

USGS Publications Warehouse

Conn, Kathleen E.; Black, Robert W.

2014-01-01

Between February and June 2013, the U.S. Geological Survey collected representative samples of whole water, suspended sediment, and (or) bed sediment from a single strategically located site on the Duwamish River, Washington, during seven periods of different flow conditions. Samples were analyzed by Washington-State-accredited laboratories for a large suite of compounds, including polycyclic aromatic hydrocarbons and other semivolatile compounds, polychlorinated biphenyl Aroclors and the 209 congeners, metals, dioxins/furans, volatile organic compounds, pesticides, butyltins, hexavalent chromium, and total organic carbon. Chemical concentrations associated with bulk bed sediment (<2 mm) and fine bed sediment (<62.5 μm) fractions were compared to chemical concentrations associated with suspended sediment. Bulk bed sediment concentrations generally were lower than fine bed sediment and suspended-sediment concentrations. Concurrent with the chemistry sampling, additional parameters were measured, including instantaneous river discharge, suspended-sediment concentration, sediment particle-size distribution, and general water-quality parameters. From these data, estimates of instantaneous sediment and chemical loads from the Green River to the Lower Duwamish Waterway were calculated.

A comparison of emissions from vehicles fueled with diesel or compressed natural gas.

PubMed

Hesterberg, Thomas W; Lapin, Charles A; Bunn, William B

2008-09-01

A comprehensive comparison of emissions from vehicles fueled with diesel or compressed natural gas (CNG) was developed from 25 reports on transit buses, school buses, refuse trucks, and passenger cars. Emissions for most compounds were highest for untreated exhaust emissions and lowest for treated exhaust CNG buses without after-treatment had the highest emissions of carbon monoxide, hydrocarbons, nonmethane hydrocarbons (NMHC), volatile organic compounds (VOCs; e.g., benzene, butadiene, ethylene, etc.), and carbonyl compounds (e.g., formaldehyde, acetaldehyde, acrolein). Diesel buses without after-treatment had the highest emissions of particulate matter and polycyclic aromatic hydrocarbons (PAHs). Exhaust after-treatments reduced most emissions to similar levels in diesel and CNG buses. Nitrogen oxides (NO(x)) and carbon dioxide (CO2) emissions were similar for most vehicle types, fuels, and exhaust after-treatments with some exceptions. Diesel school buses had higher CO2 emissions than the CNG bus. CNG transit buses and passenger cars equipped with three-way catalysts had lower NO(x) emissions. Diesel buses equipped with traps had higher nitrogen dioxide emissions. Fuel economy was best in the diesel buses not equipped with exhaust after-treatment.

77 FR 52606 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-30

... Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compounds; Architectural and... sets limits on the amount of volatile organic compounds (VOC) in architectural and industrial... Indiana SIP a new rule within Title 326, Article 8 ``Volatile Organic Compound Rules'' that limits the VOC...

Aromatic Amino Acid-Derived Compounds Induce Morphological Changes and Modulate the Cell Growth of Wine Yeast Species

PubMed Central

González, Beatriz; Vázquez, Jennifer; Cullen, Paul J.; Mas, Albert; Beltran, Gemma; Torija, María-Jesús

2018-01-01

Yeasts secrete a large diversity of compounds during alcoholic fermentation, which affect growth rates and developmental processes, like filamentous growth. Several compounds are produced during aromatic amino acid metabolism, including aromatic alcohols, serotonin, melatonin, and tryptamine. We evaluated the effects of these compounds on growth parameters in 16 different wine yeasts, including non-Saccharomyces wine strains, for which the effects of these compounds have not been well-defined. Serotonin, tryptamine, and tryptophol negatively influenced yeast growth, whereas phenylethanol and tyrosol specifically affected non-Saccharomyces strains. The effects of the aromatic alcohols were observed at concentrations commonly found in wines, suggesting a possible role in microbial interaction during wine fermentation. Additionally, we demonstrated that aromatic alcohols and ethanol are able to affect invasive and pseudohyphal growth in a manner dependent on nutrient availability. Some of these compounds showed strain-specific effects. These findings add to the understanding of the fermentation process and illustrate the diversity of metabolic communication that may occur among related species during metabolic processes. PMID:29696002

Structural features of a bituminous coal and their changes during low-temperature oxidation and loss of volatiles investigated by advanced solid-state NMR spectroscopy

USGS Publications Warehouse

Mao, J.-D.; Schimmelmann, A.; Mastalerz, Maria; Hatcher, P.G.; Li, Y.

2010-01-01

Quantitative and advanced 13C solid-state NMR techniques were employed to investigate (i) the chemical structure of a high volatile bituminous coal, as well as (ii) chemical structural changes of this coal after evacuation of adsorbed gases, (iii) during oxidative air exposure at room temperature, and (iv) after oxidative heating in air at 75 ??C. The solid-state NMR techniques employed in this study included quantitative direct polarization/magic angle spinning (DP/MAS) at a high spinning speed of 14 kHz, cross polarization/total sideband suppression (CP/TOSS), dipolar dephasing, CH, CH2, and CHn selection, 13C chemical shift anisotropy (CSA) filtering, two-dimensional (2D) 1H-13C heteronuclear correlation NMR (HETCOR), and 2D HETCOR with 1H spin diffusion. With spectral editing techniques, we identified methyl CCH 3, rigid and mobile methylene CCH2C, methine CCH, quaternary Cq, aromatic CH, aromatic carbons bonded to alkyls, small-sized condensed aromatic moieties, and aromatic C-O groups. With direct polarization combined with spectral-editing techniques, we quantified 11 different types of functional groups. 1H-13C 2D HETCOR NMR experiments indicated spatial proximity of aromatic and alkyl moieties in cross-linked structures. The proton spin diffusion experiments indicated that the magnetization was not equilibrated at a 1H spin diffusion time of 5 ms. Therefore, the heterogeneity in spatial distribution of different functional groups should be above 2 nm. Recoupled C-H long-range dipolar dephasing showed that the fraction of large charcoal-like clusters of polycondensed aromatic rings was relatively small. The exposure of this coal to atmospheric oxygen at room temperature for 6 months did not result in obvious chemical structural changes of the coal, whereas heating at 75 ??C in air for 10 days led to oxidation of coal and generated some COO groups. Evacuation removed most volatiles and caused a significant reduction in aliphatic signals in its DP/MAS spectrum. DP/MAS, but not CP/MAS, allowed us to detect the changes during low-temperature oxidation and loss of volatiles. These results demonstrate the applicability of advanced solid-state NMR techniques in chemical characterization of coal. ?? 2010 American Chemical Society.

New Findings on Aromatic Compounds' Degradation and Their Metabolic Pathways, the Biosurfactant Production and Motility of the Halophilic Bacterium Halomonas sp. KHS3.

PubMed

Corti Monzón, Georgina; Nisenbaum, Melina; Herrera Seitz, M Karina; Murialdo, Silvia E

2018-04-24

The study of the aromatic compounds' degrading ability by halophilic bacteria became an interesting research topic, because of the increasing use of halophiles in bioremediation of saline habitats and effluents. In this work, we focused on the study of aromatic compounds' degradation potential of Halomonas sp. KHS3, a moderately halophilic bacterium isolated from hydrocarbon-contaminated seawater of the Mar del Plata harbour. We demonstrated that H. sp. KHS3 is able to grow using different monoaromatic (salicylic acid, benzoic acid, 4-hydroxybenzoic acid, phthalate) and polyaromatic (naphthalene, fluorene, and phenanthrene) substrates. The ability to degrade benzoic acid and 4-hydroxybenzoic acid was analytically corroborated, and Monod kinetic parameters and yield coefficients for degradation were estimated. Strategies that may enhance substrate bioavailability such as surfactant production and chemotactic responses toward aromatic compounds were confirmed. Genomic sequence analysis of this strain allowed us to identify several genes putatively related to the metabolism of aromatic compounds, being the catechol and protocatechuate branches of β-ketoadipate pathway completely represented. These features suggest that the broad-spectrum xenobiotic degrader H. sp. KHS3 could be employed as a useful biotechnological tool for the cleanup of aromatic compounds-polluted saline habitats or effluents.

Relating sensory and chemical properties of sour cream to consumer acceptance.

PubMed

Shepard, L; Miracle, R E; Leksrisompong, P; Drake, M A

2013-09-01

Sour cream is a widely popular acidified dairy product. Volatile compounds and organic acids and their specific contributions to flavor or acceptance have not been established, nor has a comprehensive study been conducted to characterize drivers of liking for sour cream. The objective of this study was to characterize chemical and sensory properties of sour cream and to determine the drivers of liking for sour cream. Descriptive sensory and instrumental analyses followed by consumer testing were conducted. Flavor and texture attributes of 32 (22 full-fat, 6 reduced-fat, and 4 fat-free) commercial sour creams were evaluated by a trained descriptive sensory panel. Percent solids, percent fat, pH, titratable acidity, and colorimetric measurements were conducted to characterize physical properties of sour creams. Organic acids were evaluated by HPLC and volatile aroma active compounds were evaluated by gas chromatography-mass spectrometry with gas chromatography-olfactometry. Consumer acceptance testing (n=201) was conducted on selected sour creams, followed by external preference mapping. Full-fat sour creams were characterized by the lack of surface gloss and chalky textural attributes, whereas reduced-fat and fat-free samples displayed high intensities of these attributes. Full-fat sour creams were higher in cooked/milky and milk fat flavors than the reduced-fat and fat-free samples. Reduced-fat and fat-free sour creams were characterized by cardboard, acetaldehyde/green, and potato flavors, bitter taste, and astringency. Lactic acid was the prominent organic acid in all sour creams, followed by acetic and citric acids. High aroma-impact volatile compounds in sour creams were 2,3-butanedione, acetic acid, butyric acid, octanal, 2-methyl-3-furanthiol, 1-octene-3-one, and acetaldehyde. Positive drivers of liking for sour cream were milk fat, cooked/milky and sweet aromatic flavors, opacity, color intensity, and adhesiveness. This comprehensive study established sensory and instrumental properties of sour creams and their relationship to consumer acceptance. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Comparison of volatile organic compounds from lung cancer patients and healthy controls-challenges and limitations of an observational study.

PubMed

Schallschmidt, Kristin; Becker, Roland; Jung, Christian; Bremser, Wolfram; Walles, Thorsten; Neudecker, Jens; Leschber, Gunda; Frese, Steffen; Nehls, Irene

2016-10-12

This paper outlines the design and performance of an observational study on the profiles of volatile organic compounds (VOCs) in the breath of 37 lung cancer patients and 23 healthy controls of similar age. The need to quantify each VOC considered as a potential disease marker on the basis of individual calibration is elaborated, and the quality control measures required to maintain reproducibility in breath sampling and subsequent instrumental trace VOC analysis using solid phase microextraction-gas chromatography-mass spectrometry over a study period of 14 months are described. Twenty-four VOCs were quantified on the basis of their previously suggested potential as cancer markers. The concentration of aromatic compounds in the breath was increased, as expected, in smokers, while lung cancer patients displayed significantly increased levels of oxygenated VOCs such as aldehydes, 2-butanone and 1-butanol. Although sets of selected oxygenated VOCs displayed sensitivities and specificities between 80% and 90% using linear discriminant analysis (LDA) with leave-one-out cross validation, the effective selectivity of the breath VOC approach with regard to cancer detection is clearly limited. Results are discussed against the background of the literature on volatile cancer marker investigations and the prospects of linking increased VOC levels in patients' breath with approaches that employ sniffer dogs. Experience from this study and the literature suggests that the currently available methodology is not able to use breath VOCs to reliably discriminate between cancer patients and healthy controls. Observational studies often tend to note significant differences in levels of certain oxygenated VOCs, but without the resolution required for practical application. Any step towards the exploitation of differences in VOC profiles for illness detection would have to solve current restrictions set by the low and variable VOC concentrations. Further challenges are the technical complexity of studies involving breath sampling and possibly the limited capability of current analytical procedures to detect unstable marker candidates.

Chemical characterization of SOA formed from aqueous-phase reactions of phenols with the triplet excited state of carbonyl and hydroxyl radical

DOE PAGES

Yu, L.; Smith, J.; Laskin, A.; ...

2014-12-23

Phenolic compounds, which are emitted in significant amounts from biomass burning, can undergo fast reactions in atmospheric aqueous phases to form secondary organic aerosol (aqSOA). In this study, we investigate the reactions of phenol (compound with formula C 6H 5OH)), guaiacol (2-methoxyphenol), and syringol (2,6-dimethoxyphenol) with two major aqueous-phase oxidants – the triplet excited states of an aromatic carbonyl ( 3C *) and hydroxyl radical (· OH). We thoroughly characterize the low-volatility species produced from these reactions and interpret their formation mechanisms using aerosol mass spectrometry (AMS), nanospray desorption electrospray ionization mass spectrometry (nano-DESI MS), and ion chromatography (IC). Amore » large number of oxygenated molecules are identified, including oligomers containing up to six monomer units, functionalized monomer and oligomers with carbonyl, carboxyl, and hydroxyl groups, and small organic acid anions (e.g., formate, acetate, oxalate, and malate). The average atomic oxygen-to-carbon (O / C) ratios of phenolic aqSOA are in the range of 0.85–1.23, similar to those of low-volatility oxygenated organic aerosol (LV-OOA) observed in ambient air. The aqSOA compositions are overall similar for the same precursor, but the reactions mediated by 3C * are faster than · OH-mediated reactions and produce more oligomers and hydroxylated species at the point when 50% of the phenolic compound has reacted. Profiles determined using a thermodenuder indicate that the volatility of phenolic aqSOA is influenced by both oligomer content and O / C ratio. In addition, the aqSOA shows enhanced light absorption in the UV–visible region, suggesting that aqueous-phase reactions of phenols may contribute to formation of secondary brown carbon in the atmosphere, especially in regions influenced by biomass burning.« less

Volatile compounds of Aspergillus strains with different abilities to produce ochratoxin A.

PubMed

Jeleń, Henryk H; Grabarkiewicz-Szczesna, Jadwiga

2005-03-09

Volatile compounds emitted by Aspergillus strains having different abilities to produce ochratoxin A were investigated. Thirteen strains of Aspergillus ochraceus, three belonging to the A. ochraceus group, and eight other species of Aspergillus were examined for their abilities to produce volatile compounds and ochratoxin A on a wheat grain medium. The profiles of volatile compounds, analyzed using SPME, in all A. ochraceus strains, regardless of their toxeginicity, were similar and comprised mainly of 1-octen-3-ol, 3-octanone, 3-octanol, 3-methyl-1-butanol, 1-octene, and limonene. The prevailing compound was always 1-octen-3-ol. Mellein, which forms part of the ochratoxin A molecule, was found in both toxigenic and nontoxigenic strains. Volatile compounds produced by other Aspergillus strains were similar to those of A. ochraceus. Incubation temperatures (20, 24, and 27 degrees C) and water content in the medium (20, 30, and 40%) influenced both volatile compounds formation and ochratoxin A biosynthesis efficiency, although conditions providing the maximum amount of volatiles were different from those providing the maximum amount of ochratoxin A. The pattern of volatiles produced by toxigenic A. ochraceus strains does not facilitate their differentiation from nontoxigenic strains.

Airborne Exposures to Polycyclic Aromatic Compounds Among Workers in Asphalt Roofing Manufacturing Facilities.

PubMed

Trumbore, David C; Osborn, Linda V; Johnson, Kathleen A; Fayerweather, William E

2015-01-01

We studied exposure of 151 workers to polycyclic aromatic compounds and asphalt emissions during the manufacturing of asphalt roofing products-including 64 workers from 10 asphalt plants producing oxidized, straight-run, cutback, and wax- or polymer-modified asphalts, and 87 workers from 11 roofing plants producing asphalt shingles and granulated roll roofing. The facilities were located throughout the United States and used asphalt from many refiners and crude oils. This article helps fill a gap in exposure data for asphalt roofing manufacturing workers by using a fluorescence technique that targets biologically active 4-6 ring polycyclic aromatic compounds and is strongly correlated with carcinogenic activity in animal studies. Worker exposures to polycyclic aromatic compounds were compared between manufacturing plants, at different temperatures and using different raw materials, and to important external benchmarks. High levels of fine limestone particulate in the plant air during roofing manufacturing increased polycyclic aromatic compound exposure, resulting in the hypothesis that the particulate brought adsorbed polycyclic aromatic compounds to the worker breathing zone. Elevated asphalt temperatures increased exposures during the pouring of asphalt. Co-exposures in these workplaces which act as confounders for both the measurement of total organic matter and fluorescence were detected and their influence discussed. Exposures to polycyclic aromatic compounds in asphalt roofing manufacturing facilities were lower than or similar to those reported in hot-mix paving application studies, and much below those reported in studies of hot application of built-up roofing asphalt. These relatively low exposures in manufacturing are primarily attributed to air emission controls in the facilities, and the relatively moderate temperatures, compared to built-up roofing, used in these facilities for oxidized asphalt. The exposure to polycyclic aromatic compounds was a very small part of the overall worker exposure to asphalt fume, on average less than 0.07% of the benzene-soluble fraction. Measurements of benzene-soluble fraction were uniformly below the American Conference of Governmental Industrial Hygienists' Threshold Limit Value for asphalt fume.

Characterization of Neem (Azadirachta indica A. Juss) seed volatile compounds obtained by supercritical carbon dioxide process.

PubMed

Swapna Sonale, R; Ramalakshmi, K; Udaya Sankar, K

2018-04-01

Extraction process employing Supercritical fluid carbon dioxide (SCF) yields bioactive compounds near natural forms without any artifact formation. Neem seed was subjected to SCF at different temperatures and pressure conditions. These extracts were partitioned to separate volatile fraction and were analyzed by Gas Chromatography-Mass spectroscopy along with the volatiles extracted by the hydro-distillation method. Experimental results show that there is a significant effect of pressure and temperature on isolation of a number of volatile compounds as well as retention of biologically active compounds. Twenty-five volatile compounds were isolated in the Hydro-distillate compare to the SCF extract of 100 bar, 40 °C which showed forty volatile compounds corresponds to 76.38 and 92.39% of total volatiles respectively. The majority of bioactive compounds such as Terpinen-4-ol, 1,2,4-Trithiolane, 3,5-diethyl, allyl isopropyl sulphide, Cycloisolongifolene, á-Bisabolene, (-)-α-Panasinsen, Isocaryophyllene, trans-Sesquisabinene hydrate, 1-Naphthalenol, were identified in the extract when isolated at 100 bar and 40 °C.

Simultaneous control of apparent extract and volatile compounds concentrations in low-malt beer fermentation.

PubMed

Kobayashi, Michiko; Nagahisa, Keisuke; Shimizu, Hiroshi; Shioya, Suteaki

2006-12-01

Volatile compounds cause undesirable flavor when their concentrations exceed threshold values in beer fermentation. The objective of this study is to develop a system for controlling apparent extract concentration, which indicates the fermentation degree and which should be decreased below a targeted value at a fixed time under a constraint of tolerable amounts of volatile compounds. In beer fermentation, even though the production of volatile compounds is suppressed by maintaining a low fermentation temperature, a low temperature causes a delay in the control of apparent extract concentration. Volatile compound concentration was estimated on-line, and the simulation of apparent extract consumption and volatile compound production was performed. To formulate various beer tastes and conserve energy for attemperation, optimal temperature profiles were determined using a genetic algorithm (GA). The developed feedback control of the brewing temperature profile was successfully applied, and apparent extract and volatile compound concentrations at a fixed time reached their target concentrations. Additionally, the control technique developed in this study enables us to brew a wide variety of beers with different tastes.

Influence of physicochemical characteristics and high pressure processing on the volatile fraction of Iberian dry-cured ham.

PubMed

Martínez-Onandi, Nerea; Rivas-Cañedo, Ana; Ávila, Marta; Garde, Sonia; Nuñez, Manuel; Picon, Antonia

2017-09-01

The volatile fraction of 30 Iberian dry-cured hams of different physicochemical characteristics and the effect of high pressure processing (HPP) at 600MPa on volatile compounds were investigated. According to the analysis of variance carried out on the levels of 122 volatile compounds, intramuscular fat content influenced the levels of 8 benzene compounds, 5 carboxylic acids, 2 ketones, 2 furanones, 1 alcohol, 1 aldehyde and 1 sulfur compound, salt concentration influenced the levels of 1 aldehyde and 1 ketone, salt-in-lean ratio had no effect on volatile compounds, and water activity influenced the levels of 3 sulfur compounds, 1 alcohol and 1 aldehyde. HPP-treated samples of Iberian ham had higher levels of 4 compounds and lower levels of 31 compounds than untreated samples. A higher influence of HPP treatment on volatile compounds than physicochemical characteristics was observed for Iberian ham. Therefore, HPP treatment conditions should be optimized in order to diminish its possible effect on Iberian ham odor and aroma characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Air quality assessment and the use of specific markers to apportion pollutants to source

NASA Astrophysics Data System (ADS)

Douce, David Stewart

The contributions of specific polluting sources to both indoor and outdoor atmospheric pollution are difficult to determine, as solid and gaseous products from different combustion sources are often similar. Sometimes, however, a marker compound can be identified that is unique to a pollution source (or at least not present in most other local combustion sources) and which will allow assessment of the contribution of that source to total atmospheric pollution.The aim of this study was to identify suitable marker compounds and methods for the apportionment (assessment of percentage contribution) of specific sources to atmospheric pollution. The sources selected were diesel exhaust emissions in outdoor, and environmental tobacco smoke (ETS) in indoor environments. Studies with controlled (laboratory) atmospheres would be followed by field studies using these methods and markers to produce apportionments for these sources to air pollution in selected environments. Initial analysis of such polluting sources was therefore the qualitative analysis of volatile compounds and particulate associated material, both organic and inorganic. Volatile organic compounds were adsorbed onto various resins, while particulate material was sampled onto various filter paper types. Organics were determined by GC-AED and GC-MS, and elements by ICP-MS.1-Nitropyrene was identified as a suitable marker for diesel particulate emissions (<5um). A large volume air sample from Sheffield city centre using 1-nitropyrene as a marker suggested that 63% of atmospheric particulate material (<5um) might be of diesel origin. However the concentration of 1-nitropyrene is low in atmospheric samples, and in the volumes used in routine sampling the amount of 1-nitropyrene was below the limit of detection on the instrument used. In an alternative approach the aliphatic alkane tetracosane (C24) was used as a diesel marker for urban air, with a 1-nitropyrene:tetracosane ratio derived from the average results from laboratory experiments with a diesel engine running at various speeds and loads. This approach yielded apportionment values ranging from 5-85% for the diesel contribution to particulate material (<5mum) in the urban air of Sheffield. No volatile marker compound was found for diesel apportionment.The contribution of ETS to atmospheric pollution has previously been estimated from the measurement of respirable suspended particulates (RSP), which was superseded by total UV absorbance and total fluorescence of a methanol extract. More recent work has suggested the use of solanesol or scopoletin as marker compounds. This thesis shows that the non specific methods overestimated the particulate contribution of ETS in some atmospheres, and that solanesol is a better marker compound than scopoletin. Preliminary studies from a small number of smokers homes and offices, with solanesol as a marker compound for particulate ETS, indicated that ETS contributions to total particulate material (<5mum) ranged from 6 to 49% in homes and 11 to 28% in offices.Pyrrole was used as a marker for ETS contribution to volatile organic pollution, and studies with controlled atmospheres with a smoking machine allowed calculation of the ratios of pyrrole to other volatile organic compounds (VOC's) in ETS. Samples from the field study were used to produce apportionment percentage levels of benzene, toluene, o-xylene and p+m-xylene associated with ETS.In addition the use of tree bark as a atmospheric sink for airborne particulates was investigated. Six nitrated polycyclic aromatic hydrocarbons associated with diesel emissions were quantified in bark extracts and levels of these were found to be highest during winter months.

Comparison of Lichen, Conifer Needles, Passive Air Sampling Devices, and Snowpack as Passive Sampling Media to Measure Semi-Volatile Organic Compounds in Remote Atmospheres

PubMed Central

SCHRLAU, JILL E.; GEISER, LINDA; HAGEMAN, KIMBERLY J.; LANDERS, DIXON H.

2011-01-01

A wide range of semi-volatile organic compounds (SOCs), including pesticides and polycyclic aromatic hydrocarbons (PAHs), were measured in lichen, conifer needles, snowpack and XAD-based passive air sampling devices (PASDs) collected from 19 different U.S. national parks in order to compare the magnitude and mechanism of SOC accumulation in the different passive sampling media. Lichen accumulated the highest SOC concentrations, in part because of its long (and unknown) exposure period, while PASDs accumulated the lowest concentrations. However, only the PASD SOC concentrations can be used to calculate an average atmospheric gas-phase SOC concentration because the sampling rates are known and the media is uniform. Only the lichen and snowpack SOC accumulation profiles were statistically significantly correlated (r = 0.552, p-value <0.0001) because they both accumulate SOCs present in the atmospheric particle-phase. This suggests that needles and PASDs represent a different composition of the atmosphere than lichen and snowpack and that the interpretation of atmospheric SOC composition is dependent on the type of passive sampling media used. All four passive sampling media preferentially accumulated SOCs with relatively low air-water partition coefficients, while snowpack accumulated SOCs with higher log KOA values compared to the other media. Lichen accumulated more SOCs with log KOA > 10 relative to needles and showed a greater accumulation of particle-phase PAHs. PMID:22087860

Plant essential oils and allied volatile fractions as multifunctional additives in meat and fish-based food products: a review.

PubMed

Patel, Seema

2015-01-01

Essential oils are concentrated aromatic volatile compounds derived from botanicals by distillation or mechanical pressing. They play multiple, crucial roles as antioxidants, food pathogen inhibitors, shelf-life enhancers, texture promoters, organoleptic agents and toxicity-reducing agents. For their versatility, they appear promising as food preservatives. Several research findings in recent times have validated their potential as functional ingredients in meat and fish processing. Among the assortment of bioactive compounds in the essential oils, p-cymene, thymol, eugenol, carvacrol, isothiocyanate, cinnamaldehyde, cuminaldehyde, linalool, 1,8-cineol, α-pinene, α-terpineol, γ-terpinene, citral and methyl chavicol are most familiar. These terpenes (monoterpenes and sesquiterpenes) and phenolics (alcohols, esters, aldehydes and ketones) have been extracted from culinary herbs such as oregano, rosemary, basil, coriander, cumin, cinnamon, mint, sage and lavender as well as from trees such as myrtle, fir and eucalyptus. This review presents essential oils as alternatives to conventional chemical additives. Their synergistic actions with modified air packaging, irradiation, edible films, bacteriocins and plant byproducts are discussed. The decisive roles of metabolic engineering, microwave technology and metabolomics in quality and quantity augmentation of essential oil are briefly mooted. The limitations encountered and strategies to overcome them have been illuminated to pave way for their enhanced popularisation. The literature has been mined from scientific databases such as Pubmed, Pubchem, Scopus and SciFinder.

Characteristics and reactivity of volatile organic compounds from non-coal emission sources in China

NASA Astrophysics Data System (ADS)

He, Qiusheng; Yan, Yulong; Li, Hongyan; Zhang, Yiqiang; Chen, Laiguo; Wang, Yuhang

2015-08-01

Volatile organic compounds (VOCs) were sampled from non-coal emission sources including fuel refueling, solvent use, industrial and commercial activities in China, and 62 target species were determined by gas chromatography-mass selective detector (GC-MSD). Based on the results, source profiles were developed and discussed from the aspects of composition characteristics, potential tracers, BTEX (benzene, toluene, ethylbenzene and xylene) diagnostic ratios and chemical reactivity. Compared with vehicle exhausts and liquid fuels, the major components in refueling emissions of liquefied petroleum gas (LPG), gasoline and diesel were alkenes and alkanes. Oppositely, aromatics were the most abundant group in emissions from auto-painting, book binding and plastic producing. Three groups contributed nearly equally in printing and commercial cooking emissions. Acetone in medical producing, chloroform and tetrachloroethylene in wet- and dry-cleaning, as well as TEX in plastic producing etc. were good tracers for the respective sources. BTEX ratios showed that some but not all VOCs sources could be distinguished by B/T, B/E and B/X ratios, while T/E, T/X and E/X ratios were not suitable as diagnostic indicators of different sources. The following reactivity analysis indicated that emissions from gasoline refueling, commercial cooking, auto painting and plastic producing had high atmospheric reactivity, and should be controlled emphatically to prevent ozone pollution, especially when there were large amounts of emissions for them.

Volatile organic compounds in a multi-storey shopping mall in guangzhou, South China

NASA Astrophysics Data System (ADS)

Tang, Jianhui; Chan, C. Y.; Wang, Xinming; Chan, L. Y.; Sheng, Guoying; Fu, Jiamo

Volatile organic compounds (VOCs) specified in the USEPA TO-14 list were analysed in microenvironments of a multi-storey shopping mall in Guangzhou city, South China. The microenvironments studied include both indoor (department store, supermarket, fast-food court, electronic games room, children's playground, gallery and book store) and outdoor ones (rooftop and ground level entrance). The characteristics and concentration of VOCs varied widely in differing microenvironments. The average concentrations of the total VOCs in the indoor microenvironments ranged from 178.5 to 457.7 μg m -3 with a maximum of 596.8 μg m -3. The fast-food court and a leather products department store had the highest concentrations of benzene, toluene, ethylbenzene, xylenes and chlorinated hydrocarbons. A high level of 1,4-dichlorobenzene was found in all indoor microenvironments with an average of 12.3 μg m -3 and a maximum of 44.3 μg m -3. The ratios of average indoor to outdoor concentrations (I/O ratio) in all indoor microenvironments fell between 1 and 3, except an average of 24.6 and a maximum of 77.8 in the fashion department store for 1,4-dichlorobenzene. Indoor emission sources of monocyclic aromatic hydrocarbons in the shopping mall might include cooking stoves, leather products and building materials. Chlorinated hydrocarbons, however, were possibly connected with their use as cleaning agents or deodorizers.

Oral bioaccessibility of semi-volatile organic compounds (SVOCs) in settled dust: A review of measurement methods, data and influencing factors.

PubMed

Raffy, Gaëlle; Mercier, Fabien; Glorennec, Philippe; Mandin, Corinne; Le Bot, Barbara

2018-06-15

Many semi-volatile organic compounds (SVOCs), suspected of reprotoxic, neurotoxic or carcinogenic effects, were measured in indoor settled dust. Dust ingestion is a non-negligible pathway of exposure to some of these SVOCs, and an accurate knowledge of the real exposure is necessary for a better evaluation of health risks. To this end, the bioaccessibility of SVOCs in dust needs to be considered. In the present work, bioaccessibility measurement methods, SVOCs' oral bioaccessibility data and influencing factors were reviewed. SVOC bioaccessibilities (%) ranged from 11 to 94, 8 to 100, 3 to 92, 1 to 81, 6 to 52, and 2 to 17, for brominated flame retardants, organophosphorus flame retardants, polychlorobiphenyls, phthalates, pesticides and polycyclic aromatic hydrocarbons, respectively. Measurements method produced varying results depending on the inclusion of food and/or sink in the model. Characteristics of dust, e.g., organic matter content and particle size, also influenced bioaccessibility data. Last, results were influenced by SVOC properties, such as octanol/water partition coefficient and migration pathway into dust. Factors related to dust and SVOCs could be used in prediction models. To this end, more bioaccessibility studies covering more substances should be performed, using methods that are harmonized and validated by comparison to in-vivo studies. Copyright © 2018 Elsevier B.V. All rights reserved.

Evolution of Volatile Compounds during the Distillation of Cognac Spirit.

PubMed

Awad, Pierre; Athès, Violaine; Decloux, Martine Esteban; Ferrari, Gérald; Snakkers, Guillaume; Raguenaud, Patrick; Giampaoli, Pierre

2017-09-06

Cognac wine spirit has a complex composition in volatile compounds which contributes to its organoleptic profile. This work focused on the batch distillation process and, in particular, on volatile compounds specifically produced by chemical reactions during the distillation of Cognac wine spirit, traditionally conducted in two steps with charentais pot stills. The aim of this study was to characterize these volatile compounds formed during distillation. Sampling has been performed on the distillates and inside the boiler during a typical Cognac distillation. The analysis of these samples allowed us to perform a mass balance and to point out several types of volatile compounds whose quantities strongly increased during the distillation process. These compounds were distinguished by their chemical family. It has been found that the first distillation step was decisive for the formation of volatile compounds. Moreover, 2 esters, 3 aldehydes, 12 norisoprenoids, and 3 terpenes were shown to be generated during the process. These results suggest that some volatile compounds found in Cognac spirit are formed during distillation due to chemical reactions induced by high temperature. These findings give important indications to professional distillers in order to enhance the product's quality.

78 FR 11618 - Approval and Promulgation of Implementation Plans Tennessee: Revisions to Volatile Organic...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-19

... Promulgation of Implementation Plans Tennessee: Revisions to Volatile Organic Compound Definition AGENCY..., SIP revision adds 17 compounds to the list of compounds excluded from the definition of ``Volatile Organic Compound''. EPA is approving this SIP revision because the State has demonstrated that it is...

An Organic Geochemical Assessment of CO2-Coal Interactions During Sequestration

USGS Publications Warehouse

Kolak, Jonathan J.; Burruss, Robert A.

2003-01-01

Three well-characterized coal samples of varying rank were extracted with supercritical CO2 to determine the amount of polycyclic aromatic hydrocarbons (PAHs) that could be mobilized during simulated CO2 injection/sequestration in deep coal beds. The supercritical CO2 extractions were conducted at 40?C and 100 bars, roughly corresponding to a depth of 1 km. The greatest amount of PAHs was extracted from the high-volatile C bituminous coal sample. Extracts from the subbituminous C and anthracite coal samples contained lower concentrations of these compounds. The effectiveness of supercritical CO2 in liberating PAHs from the coal sample was evaluated in a comparison with a parallel series of Soxhlet extractions using 100% dichloromethane. More PAHs were extracted from the lower rank coal samples with dichloromethane than with supercritical CO2. The results from this investigation indicate that, regardless of coal rank, CO2 injection into deep coal beds may mobilize PAHs from the coal matrix. However, more PAHs could be mobilized during CO2 sequestration in a high-volatile C bituminous coal bed than in either of the other two coal ranks studied.

A new methodology capable of characterizing most volatile and less volatile minor edible oils components in a single chromatographic run without solvents or reagents. Detection of new components.

PubMed

Alberdi-Cedeño, Jon; Ibargoitia, María L; Cristillo, Giovanna; Sopelana, Patricia; Guillén, María D

2017-04-15

The possibilities offered by a new methodology to determine minor components in edible oils are described. This is based on immersion of a solid-phase microextraction fiber of PDMS/DVB into the oil matrix, followed by Gas Chromatography/Mass Spectrometry. It enables characterization and differentiation of edible oils in a simple way, without either solvents or sample modification. This methodology allows simultaneous identification and quantification of sterols, tocols, hydrocarbons of different natures, fatty acids, esters, monoglycerides, fatty amides, aldehydes, ketones, alcohols, epoxides, furans, pyrans and terpenic oxygenated derivatives. The broad information provided by this methodology is useful for different areas of interest such as nutritional value, oxidative stability, technological performance, quality, processing, safety and even the prevention of fraudulent practices. Furthermore, for the first time, certain fatty amides, gamma- and delta-lactones of high molecular weight, and other aromatic compounds such as some esters derived from cinnamic acid have been detected in edible oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Description of gas/particle sorption kinetics with an intraparticle diffusion model: Desorption experiments

USGS Publications Warehouse

Rounds, S.A.; Tiffany, B.A.; Pankow, J.F.

1993-01-01

Aerosol particles from a highway tunnel were collected on a Teflon membrane filter (TMF) using standard techniques. Sorbed organic compounds were then desorbed for 28 days by passing clean nitrogen through the filter. Volatile n-alkanes and polycyclic aromatic hydrocarbons (PAHs) were liberated from the filter quickly; only a small fraction of the less volatile ra-alkanes and PAHs were desorbed. A nonlinear least-squares method was used to fit an intraparticle diffusion model to the experimental data. Two fitting parameters were used: the gas/particle partition coefficient (Kp and an effective intraparticle diffusion coefficient (Oeff). Optimized values of Kp are in agreement with previously reported values. The slope of a correlation between the fitted values of Deff and Kp agrees well with theory, but the absolute values of Deff are a factor of ???106 smaller than predicted for sorption-retarded, gaseous diffusion. Slow transport through an organic or solid phase within the particles or preferential flow through the bed of particulate matter on the filter might be the cause of these very small effective diffusion coefficients. ?? 1993 American Chemical Society.

Evaluation of Beer Fermentation with a Novel Yeast
Williopsis saturnus

PubMed Central

Quek, Althea Ying Hui

2016-01-01

Summary The aim of this study is to evaluate the potential of a novel yeast Williopsis saturnus var. mrakii NCYC 500 to produce fruity beer. Fermentation performance of W. mrakii and beer volatile composition were compared against that fermented with Saccharomyces cerevisiae Safale US-05. oBrix, sugar and pH differed significantly between the two types of beer. A total of 8 alcohols, 11 acids, 41 esters, 9 aldehydes, 8 ketones, 21 terpenes and terpenoids, 5 Maillard reaction products and 2 volatile phenolic compounds were detected. Yeast strain Safale US-05 was more capable of producing a wider range of ethyl and other esters, while yeast strain NCYC 500 produced significantly higher amounts of acetate esters. Strain NCYC 500 retained more terpenes and terpenoids, suggesting that the resultant beer could possess more of the aromatic hint of hops. This study showed that W. saturnus var. mrakii NCYC 500 could ferment wort to produce low-alcohol beer with higher levels of acetate esters, terpenes and terpenoids than yeast S. cerevisiae Safale US-05. PMID:28115897

A full mass spectrum evaluation of semivolatile organic compounds measured during the Southern Oxidant and Aerosol Study in Alabama, USA, 2013

NASA Astrophysics Data System (ADS)

Holzinger, Rupert; Khan, Anwar; Misztal, Pawel; Goldstein, Allen

2016-04-01

A serial 3-stage denuder system has been developed and for the first time deployed during the Southern Oxidant and Aerosol Study (SOAS) in Centreville, Alabama, USA, for one month during the summer of 2013. Volatile organic compounds (VOCs) were collected on an activated carbon denuder and thermally desorbed to be measured with PTR-MS (PTR-TOF800, Ionicon Analytik GmbH). Comparison with a second PTR-MS instrument operated under standard conditions at the same site revealed poor recovery for the majority of the VOCs while individual species measured by the different PTR-MS systems still exhibited excellent correlation. Semivolatile organic compounds (SVOCs) in the gas phase were collected and thermally desorbed on a denuder coated with Methylsiloxane (Agilent DB-1). More than 100 SVOCs have been detected at levels in the range 0.05-3 pmmol/mol and only a few species exhibited maximum mixing ratios above 5 pmol/mol. Many of the detected species exhibited a clear diurnal profile while the concentration of some was clearly dominated by pollution events. Carboxylic acids, (oxidized) polycyclic aromatic compounds, and monoterpene oxidation products were compound groups that provided most of the mass and a typical total concentration of the measured burden of SVOCs was 5 microgram per cubic meter.

Automated Solid Phase Extraction (SPE) LC/NMR Applied to the Structural Analysis of Extractable Compounds from a Pharmaceutical Packaging Material of Construction.

PubMed

Norwood, Daniel L; Mullis, James O; Davis, Mark; Pennino, Scott; Egert, Thomas; Gonnella, Nina C

2013-01-01

The structural analysis (i.e., identification) of organic chemical entities leached into drug product formulations has traditionally been accomplished with techniques involving the combination of chromatography with mass spectrometry. These include gas chromatography/mass spectrometry (GC/MS) for volatile and semi-volatile compounds, and various forms of liquid chromatography/mass spectrometry (LC/MS or HPLC/MS) for semi-volatile and relatively non-volatile compounds. GC/MS and LC/MS techniques are complementary for structural analysis of leachables and potentially leachable organic compounds produced via laboratory extraction of pharmaceutical container closure/delivery system components and corresponding materials of construction. Both hyphenated analytical techniques possess the separating capability, compound specific detection attributes, and sensitivity required to effectively analyze complex mixtures of trace level organic compounds. However, hyphenated techniques based on mass spectrometry are limited by the inability to determine complete bond connectivity, the inability to distinguish between many types of structural isomers, and the inability to unambiguously determine aromatic substitution patterns. Nuclear magnetic resonance spectroscopy (NMR) does not have these limitations; hence it can serve as a complement to mass spectrometry. However, NMR technology is inherently insensitive and its ability to interface with chromatography has been historically challenging. This article describes the application of NMR coupled with liquid chromatography and automated solid phase extraction (SPE-LC/NMR) to the structural analysis of extractable organic compounds from a pharmaceutical packaging material of construction. The SPE-LC/NMR technology combined with micro-cryoprobe technology afforded the sensitivity and sample mass required for full structure elucidation. Optimization of the SPE-LC/NMR analytical method was achieved using a series of model compounds representing the chemical diversity of extractables. This study demonstrates the complementary nature of SPE-LC/NMR with LC/MS for this particular pharmaceutical application. The identification of impurities leached into drugs from the components and materials associated with pharmaceutical containers, packaging components, and materials has historically been done using laboratory techniques based on the combination of chromatography with mass spectrometry. Such analytical techniques are widely recognized as having the selectivity and sensitivity required to separate the complex mixtures of impurities often encountered in such identification studies, including both the identification of leachable impurities as well as potential leachable impurities produced by laboratory extraction of packaging components and materials. However, while mass spectrometry-based analytical techniques have limitations for this application, newer analytical techniques based on the combination of chromatography with nuclear magnetic resonance spectroscopy provide an added dimension of structural definition. This article describes the development, optimization, and application of an analytical technique based on the combination of chromatography and nuclear magnetic resonance spectroscopy to the identification of potential leachable impurities from a pharmaceutical packaging material. The complementary nature of the analytical techniques for this particular pharmaceutical application is demonstrated.

Measurements of Volatile Organic Compounds Using Proton Transfer Reaction - Mass Spectrometry during the MILAGRO 2006 Campaign

NASA Astrophysics Data System (ADS)

Fortner, E. C.; Zheng, J.; Zhang, R.; Berk Knighton, W.; Volkamer, R. M.; Sheehy, P.; Molina, L.; André, M.

2009-01-01

Volatile organic compounds (VOCs) were measured by proton transfer reaction - mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of the Megacity Initiative - Local and Global Research Observations (MILAGRO) 2006 field campaign. Thirty eight individual masses were monitored during the campaign and many species were quantified including methanol, acetaldehyde, toluene, the sum of C2 benzenes, the sum of C3 benzenes, acetone, isoprene, benzene, and ethyl acetate. The VOC measurements were analyzed to gain a better understanding of the type of VOCs present in the MCMA, their diurnal patterns, and their origins. Diurnal profiles of weekday and weekend/holiday aromatic VOC concentrations showed the influence of vehicular traffic during the morning rush hours and during the afternoon hours. Plumes including elevated toluene as high as 216 parts per billion (ppb) and ethyl acetate as high as 183 ppb were frequently observed during the late night and early morning hours, indicating the possibility of significant industrial sources of the two compounds in the region. Wind fields during those peak episodes revealed no specific direction for the majority of the toluene plumes but the ethyl acetate plumes arrived at the site when winds were from the Southwest or West. The PTR-MS measurements combined with other VOC measuring techniques at the field site as well as VOC measurements conducted in other areas of the Mexico City Metropolitan Area (MCMA) will help to develop a better understanding of the spatial pattern of VOCs and its variability in the MCMA.

Semi-volatile organic compounds in the particulate phase in dwellings: A nationwide survey in France

NASA Astrophysics Data System (ADS)

Mandin, Corinne; Mercier, Fabien; Ramalho, Olivier; Lucas, Jean-Paul; Gilles, Erwann; Blanchard, Olivier; Bonvallot, Nathalie; Glorennec, Philippe; Le Bot, Barbara

2016-07-01

Sixty-six semi-volatile organic compounds (SVOCs)-phthalates, polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), one pyrethroid, organochlorine and organophosphorous pesticides, alkylphenols, synthetic musks, tri-n-butylphosphate and triclosan-were measured on PM10 filters collected over 7 days during a nationwide survey of 285 French dwellings, representative of nearly 25 million housing units. Thirty-five compounds were detected in more than half of the dwellings. PAHs, phthalates and triclosan were the major particle-bound SVOCs, with a median concentration greater than 1 ng m-3 for butylbenzyl phthalate (BBP) (median: 1.6 ng m-3), di(2-ethylhexyl) phthalate (DEHP) (46 ng m-3) and di-iso-nonyl phthalate (DiNP) (7.9 ng m-3), and greater than 0.1 ng m-3 for triclosan (114 pg m-3), benzo(a)pyrene (138 pg m-3), benzo(b)fluoranthene (306 pg m-3), benzo(g,h,i)perylene (229 pg m-3), and indeno(1,2,3-c,d)pyrene (178 pg m-3). For most of the SVOCs, higher concentrations were found in the dwellings of smokers and during the heating season. The concentrations of banned SVOCs-namely, PCBs and organochlorine pesticides-were correlated. Permethrin, 4-tert-butylphenol and bisphenol-A showed no correlation with the other SVOCs and seemed to have their own specific sources. Most SVOCs were positively associated with PM10 concentration, suggesting that any factor that raises the mass of indoor airborne particles also increases the exposure to SVOCs through inhalation.

Determination of volatile organic compound emissions and ozone formation from spraying solvent-based pesticides.

PubMed

Kumar, Anuj; Howard, Cody J; Derrick, Doniche; Malkina, Irina L; Mitloehner, Frank M; Kleeman, Michael J; Alaimo, Christopher P; Flocchini, Robert G; Green, Peter G

2011-01-01

Large-scale agricultural activities have come under scrutiny for possible contributions to the emission of ozone precursors. The San Joaquin Valley (SJV) of California is an area with intense agricultural activity that exceeds the federal ozone standards for more than 30 to 40 d yr(-1) and the more stringent state standards for more than 100 d yr(-1). Pesticides are used widely in both agricultural and residential subregions of the SJV, but the largest use, by weight of "active ingredient," is in agriculture. The objective of the study was to determine the role of pesticide application on airborne volatile organic compounds (VOC) concentrations and ozone formation in the SJV. The ozone formation from the pesticide formulation sprayed on commercial orchards was studied using two transportable smog chambers at four application sites during the summers of 2007 and 2008. In addition to the direct measurements of ozone formation, airborne VOC concentrations were measured before and after pesticide spraying using canister and sorbent tube sampling techniques. Soil VOC concentrations were also measured to understand the distribution of VOCs between different environmental compartments. Numerous VOCs were detected in the air and soil samples throughout the experiment but higher molecular weight aromatic hydrocarbons were the primary compounds observed in elevated concentrations immediately after pesticide spraying. Measurements indicate that the ozone concentration formed by VOC downwind of the orchard may increase up to 15 ppb after pesticide application, with a return back to prespray levels after 1 to 2 d. by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Highly elevated atmospheric levels of volatile organic compounds in the Uintah Basin, Utah.

PubMed

Helmig, D; Thompson, C R; Evans, J; Boylan, P; Hueber, J; Park, J-H

2014-05-06

Oil and natural gas production in the Western United States has grown rapidly in recent years, and with this industrial expansion, growing environmental concerns have arisen regarding impacts on water supplies and air quality. Recent studies have revealed highly enhanced atmospheric levels of volatile organic compounds (VOCs) from primary emissions in regions of heavy oil and gas development and associated rapid photochemical production of ozone during winter. Here, we present surface and vertical profile observations of VOC from the Uintah Basin Winter Ozone Studies conducted in January-February of 2012 and 2013. These measurements identify highly elevated levels of atmospheric alkane hydrocarbons with enhanced rates of C2-C5 nonmethane hydrocarbon (NMHC) mean mole fractions during temperature inversion events in 2013 at 200-300 times above the regional and seasonal background. Elevated atmospheric NMHC mole fractions coincided with build-up of ambient 1-h ozone to levels exceeding 150 ppbv (parts per billion by volume). The total annual mass flux of C2-C7 VOC was estimated at 194 ± 56 × 10(6) kg yr(-1), equivalent to the annual VOC emissions of a fleet of ∼100 million automobiles. Total annual fugitive emission of the aromatic compounds benzene and toluene, considered air toxics, were estimated at 1.6 ± 0.4 × 10(6) and 2.0 ± 0.5 × 10(6) kg yr(-1), respectively. These observations reveal a strong causal link between oil and gas emissions, accumulation of air toxics, and significant production of ozone in the atmospheric surface layer.

Amino Acids, Aromatic Compounds, and Carboxylic Acids: How Did They Get Their Common Names?

ERIC Educational Resources Information Center

Leung, Sam H.

2000-01-01

Surveys the roots of the common names of organic compounds most likely to be encountered by undergraduate organic chemistry students. Includes information for 19 amino acids, 17 aromatic compounds, and 21 carboxylic acids. (WRM)

Multi-Phase Equilibrium and Solubilities of Aromatic Compounds and Inorganic Compounds in Sub- and Supercritical Water: A Review.

PubMed

Liu, Qinli; Ding, Xin; Du, Bowen; Fang, Tao

2017-11-02

Supercritical water oxidation (SCWO), as a novel and efficient technology, has been applied to wastewater treatment processes. The use of phase equilibrium data to optimize process parameters can offer a theoretical guidance for designing SCWO processes and reducing the equipment and operating costs. In this work, high-pressure phase equilibrium data for aromatic compounds+water systems and inorganic compounds+water systems are given. Moreover, thermodynamic models, equations of state (EOS) and empirical and semi-empirical approaches are summarized and evaluated. This paper also lists the existing problems of multi-phase equilibria and solubility studies on aromatic compounds and inorganic compounds in sub- and supercritical water.

Volatile composition of some Brazilian fruits: umbu-caja (Spondias citherea), camu-camu (Myrciaria dubia), Araça-boi (Eugenia stipitata), and Cupuaçu (Theobroma grandiflorum).

PubMed

Franco, M R; Shibamoto, T

2000-04-01

Twenty-one volatile compounds were identified for the first time by GC-MS in umbu-caja and in camu-camu, plus 30 volatile compounds were identified in araça-boi samples. Terpenic compounds predominated among the volatile compounds in these fruit samples, with the major compounds being identified as cis-beta-ocimene and caryophyllene in the northeastern fruit; alpha-pinene and d-limonene were the most abundant volatile compounds in the headspace of the Amazonian fruit camu-camu. Sesquiterpenes were the most abundant compounds in the araça-boi sample, with germacrene D presenting a higher relative percentage. The chemical class of esters predominated in the cupuaçu sample. Ethyl butyrate and hexanoate were the major compounds in the headspace of this Amazonian fruit.

"More than Honey": Investigation on Volatiles from Monovarietal Honeys Using New Analytical and Sensory Approaches.

PubMed

Siegmund, Barbara; Urdl, Katharina; Jurek, Andrea; Leitner, Erich

2018-03-14

Eight monovarietal honeys from dandelion, fir tree, linden tree, chestnut tree, robinia, orange, lavender, and rape were investigated with respect to their volatile compounds and sensory properties. Analysis of the volatile compounds was performed by gas chromatographic techniques (one-dimensional GC-MS as well as comprehensive GC×GC-MS). For sensory evaluation Napping in combination with ultraflash profiling was applied using sensory experts. For dandelion honey, 34 volatile compounds are described for the first time to be present in dandelion honey. PCA and cluster analysis of the volatile compounds, respectively, show high correlation with the PCA obtained from sensory evaluation. Lavender and linden honey showed sensory characteristics that were not expected from these honey types. Analysis of the volatile compounds resulted in the identification of odor-active compounds that are very likely derived from sources other than the respective honeyflow. Contamination with essential oils used in apiculture is very likely to be the reason for the occurrence of these compounds in the investigated honeys.

Cytosolic and Plastoglobule-targeted Carotenoid Dioxygenases from Crocus sativus Are Both Involved in β-Ionone Release*

PubMed Central

Rubio, Angela; Rambla, José Luís; Santaella, Marcella; Gómez, M. Dolores; Orzaez, Diego; Granell, Antonio; Gómez-Gómez, Lourdes

2008-01-01

Saffron, the processed stigma of Crocus sativus, is characterized by the presence of several apocarotenoids that contribute to the color, flavor, and aroma of the spice. However, little is known about the synthesis of aroma compounds during the development of the C. sativus stigma. The developing stigma is nearly odorless, but before and at anthesis, the aromatic compound β-ionone becomes the principal norisoprenoid volatile in the stigma. In this study, four carotenoid cleavage dioxygenase (CCD) genes, CsCCD1a, CsCCD1b, CsCCD4a, and CsCCD4b, were isolated from C. sativus. Expression analysis showed that CsCCD1a was constitutively expressed, CsCCD1b was unique to the stigma tissue, but only CsCCD4a and -b had expression patterns consistent with the highest levels of β-carotene and emission of β-ionone derived during the stigma development. The CsCCD4 enzymes were localized in plastids and more specifically were present in the plastoglobules. The enzymatic activities of CsCCD1a, CsCCD1b, and CsCCD4 enzymes were determined by Escherichia coli expression, and subsequent analysis of the volatile products was generated by GC/MS. The four CCDs fell in two phylogenetically divergent dioxygenase classes, but all could cleave β-carotene at the 9,10(9′,10′) positions to yield β-ionone. The data obtained suggest that all four C. sativus CCD enzymes may contribute in different ways to the production of β-ionone. In addition, the location and precise timing of β-ionone synthesis, together with its known activity as a fragrance and insect attractant, suggest that this volatile may have a role in Crocus pollination. PMID:18611853

Analysis of Volatile Compounds by Advanced Analytical Techniques and Multivariate Chemometrics.

PubMed

Lubes, Giuseppe; Goodarzi, Mohammad

2017-05-10

Smelling is one of the five senses, which plays an important role in our everyday lives. Volatile compounds are, for example, characteristics of food where some of them can be perceivable by humans because of their aroma. They have a great influence on the decision making of consumers when they choose to use a product or not. In the case where a product has an offensive and strong aroma, many consumers might not appreciate it. On the contrary, soft and fresh natural aromas definitely increase the acceptance of a given product. These properties can drastically influence the economy; thus, it has been of great importance to manufacturers that the aroma of their food product is characterized by analytical means to provide a basis for further optimization processes. A lot of research has been devoted to this domain in order to link the quality of, e.g., a food to its aroma. By knowing the aromatic profile of a food, one can understand the nature of a given product leading to developing new products, which are more acceptable by consumers. There are two ways to analyze volatiles: one is to use human senses and/or sensory instruments, and the other is based on advanced analytical techniques. This work focuses on the latter. Although requirements are simple, low-cost technology is an attractive research target in this domain; most of the data are generated with very high-resolution analytical instruments. Such data gathered based on different analytical instruments normally have broad, overlapping sensitivity profiles and require substantial data analysis. In this review, we have addressed not only the question of the application of chemometrics for aroma analysis but also of the use of different analytical instruments in this field, highlighting the research needed for future focus.

Construction and Optimization of a Heterologous Pathway for Protocatechuate Catabolism in Escherichia coli Enables Bioconversion of Model Aromatic Compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clarkson, Sonya M.; Giannone, Richard J.; Kridelbaugh, Donna M.

The production of biofuels from lignocellulose yields a substantial lignin by-product stream that currently has few applications. Biological conversion of lignin-derived compounds into chemicals and fuels has the potential to improve the economics of lignocellulose-derived biofuels, but few microbes are able both to catabolize lignin-derived aromatic compounds and to generate valuable products. WhileEscherichia colihas been engineered to produce a variety of fuels and chemicals, it is incapable of catabolizing most aromatic compounds. Therefore, we engineeredE. colito catabolize protocatechuate, a common intermediate in lignin degradation, as the sole source of carbon and energy via heterologous expression of a nine-gene pathway fromPseudomonasmore » putidaKT2440. Then, we used experimental evolution to select for mutations that increased growth with protocatechuate more than 2-fold. Increasing the strength of a single ribosome binding site in the heterologous pathway was sufficient to recapitulate the increased growth. After optimization of the core pathway, we extended the pathway to enable catabolism of a second model compound, 4-hydroxybenzoate. These engineered strains will be useful platforms to discover, characterize, and optimize pathways for conversions of lignin-derived aromatics. IMPORTANCELignin is a challenging substrate for microbial catabolism due to its polymeric and heterogeneous chemical structure. Therefore, engineering microbes for improved catabolism of lignin-derived aromatic compounds will require the assembly of an entire network of catabolic reactions, including pathways from genetically intractable strains. By constructing defined pathways for aromatic compound degradation in a model host would allow rapid identification, characterization, and optimization of novel pathways. Finally, we constructed and optimized one such pathway inE. colito enable catabolism of a model aromatic compound, protocatechuate, and then extended the pathway to a related compound, 4-hydroxybenzoate. This optimized strain can now be used as the basis for the characterization of novel pathways.« less

Construction and Optimization of a Heterologous Pathway for Protocatechuate Catabolism in Escherichia coli Enables Bioconversion of Model Aromatic Compounds.

PubMed

Clarkson, Sonya M; Giannone, Richard J; Kridelbaugh, Donna M; Elkins, James G; Guss, Adam M; Michener, Joshua K

2017-09-15

The production of biofuels from lignocellulose yields a substantial lignin by-product stream that currently has few applications. Biological conversion of lignin-derived compounds into chemicals and fuels has the potential to improve the economics of lignocellulose-derived biofuels, but few microbes are able both to catabolize lignin-derived aromatic compounds and to generate valuable products. While Escherichia coli has been engineered to produce a variety of fuels and chemicals, it is incapable of catabolizing most aromatic compounds. Therefore, we engineered E. coli to catabolize protocatechuate, a common intermediate in lignin degradation, as the sole source of carbon and energy via heterologous expression of a nine-gene pathway from Pseudomonas putida KT2440. We next used experimental evolution to select for mutations that increased growth with protocatechuate more than 2-fold. Increasing the strength of a single ribosome binding site in the heterologous pathway was sufficient to recapitulate the increased growth. After optimization of the core pathway, we extended the pathway to enable catabolism of a second model compound, 4-hydroxybenzoate. These engineered strains will be useful platforms to discover, characterize, and optimize pathways for conversions of lignin-derived aromatics. IMPORTANCE Lignin is a challenging substrate for microbial catabolism due to its polymeric and heterogeneous chemical structure. Therefore, engineering microbes for improved catabolism of lignin-derived aromatic compounds will require the assembly of an entire network of catabolic reactions, including pathways from genetically intractable strains. Constructing defined pathways for aromatic compound degradation in a model host would allow rapid identification, characterization, and optimization of novel pathways. We constructed and optimized one such pathway in E. coli to enable catabolism of a model aromatic compound, protocatechuate, and then extended the pathway to a related compound, 4-hydroxybenzoate. This optimized strain can now be used as the basis for the characterization of novel pathways. Copyright © 2017 American Society for Microbiology.

Antimicrobial Properties of Plant Essential Oils against Human Pathogens and Their Mode of Action: An Updated Review

PubMed Central

2016-01-01

A wide range of medicinal and aromatic plants (MAPs) have been explored for their essential oils in the past few decades. Essential oils are complex volatile compounds, synthesized naturally in different plant parts during the process of secondary metabolism. Essential oils have great potential in the field of biomedicine as they effectively destroy several bacterial, fungal, and viral pathogens. The presence of different types of aldehydes, phenolics, terpenes, and other antimicrobial compounds means that the essential oils are effective against a diverse range of pathogens. The reactivity of essential oil depends upon the nature, composition, and orientation of its functional groups. The aim of this article is to review the antimicrobial potential of essential oils secreted from MAPs and their possible mechanisms of action against human pathogens. This comprehensive review will benefit researchers who wish to explore the potential of essential oils in the development of novel broad-spectrum key molecules against a broad range of drug-resistant pathogenic microbes. PMID:28090211

Constituents and Pharmacological Activities of Myrcia (Myrtaceae): A Review of an Aromatic and Medicinal Group of Plants.

PubMed

Cascaes, Márcia Moraes; Guilhon, Giselle Maria Skelding Pinheiro; de Aguiar Andrade, Eloisa Helena; das Graças Bichara Zoghbi, Maria; da Silva Santos, Lourivaldo

2015-10-09

Myrcia is one of the largest genera of the economically important family Myrtaceae. Some of the species are used in folk medicine, such as a group known as "pedra-hume-caá" or "pedra-ume-caá" or "insulina vegetal" (insulin plant) that it is used for the treatment of diabetes. The species are an important source of essential oils, and most of the chemical studies on Myrcia describe the chemical composition of the essential oils, in which mono- and sesquiterpenes are predominant. The non-volatile compounds isolated from Myrcia are usually flavonoids, tannins, acetophenone derivatives and triterpenes. Anti-inflammatory, antinociceptive, antioxidant, antimicrobial activities have been described to Myrcia essential oils, while hypoglycemic, anti-hemorrhagic and antioxidant activities were attributed to the extracts. Flavonoid glucosides and acetophenone derivatives showed aldose reductase and α-glucosidase inhibition, and could explain the traditional use of Myrcia species to treat diabetes. Antimicrobial and anti-inflammatory are some of the activities observed for other isolated compounds from Myrcia.

NMR, HS-SPME-GC/MS, and HPLC/MSn Analyses of Phytoconstituents and Aroma Profile of Rosmarinus eriocalyx.

PubMed

Bendif, Hamdi; Miara, Mohamed Djamel; Peron, Gregorio; Sut, Stefania; Dall'Acqua, Stefano; Flamini, Guido; Maggi, Filippo

2017-10-01

In this work, a comprehensive study on the chemical constituents of the aerial parts of Rosmarinus eriocalyx (Lamiaceae), an aromatic shrub traditionally consumed as a food and herbal remedy in Algeria, is presented. The aroma profile was analysed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC/MS), whereas the crude extract constituents were analyzed by 1 H-NMR and by high performance liquid chromatography coupled with mass spectrometry (HPLC/MS n ). Thirty-nine volatile compounds, most of them being monoterpenes, have been identified, with camphor, camphene, and α-pinene as the most abundant constituents. 1 H-NMR analysis revealed the presence of phenolic compounds and betulinic acid while HPLC/MS n allowed the identification of glycosilated and aglyconic flavonoids as well as phenylpropanoid derivatives. Some of these constituents, namely as betulinic acid, rosmanol, and cirsimaritin were reported for the first time in R. eriocalyx. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Bioremediation of PAHs and VOCs: Advances in clay mineral-microbial interaction.

PubMed

Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

2015-12-01

Bioremediation is an effective strategy for cleaning up organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Advanced bioremediation implies that biotic agents are more efficient in degrading the contaminants completely. Bioremediation by microbial degradation is often employed and to make this process efficient, natural and cost-effective materials can serve as supportive matrices. Clay/modified clay minerals are effective adsorbents of PAHs/VOCs, and readily available substrate and habitat for microorganisms in the natural soil and sediment. However, the mechanism underpinning clay-mediated biodegradation of organic compounds is often unclear, and this requires critical investigation. This review describes the role of clay/modified clay minerals in hydrocarbon bioremediation through interaction with microbial agents in specific scenarios. The vision is on a faster, more efficient and cost-effective bioremediation technique using clay-based products. This review also proposes future research directions in the field of clay modulated microbial degradation of hydrocarbons. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance and limits of liquid chromatography isotope ratio mass spectrometry system for halogenated compounds

NASA Astrophysics Data System (ADS)

Gilevska, Tetyana; Gehre, Matthias; Richnow, Hans

2014-05-01

Compound Specific Isotope Analysis (CSIA) has been an important step for the assessment of the origin and fate of compounds in environmental science.[1] Biologically or pharmaceutically important compounds often are not amenable for gas chromatographic separation because of high polarity and lacking volatility, thermostability. In 2004 liquid chromatography isotope ratio mass spectrometry (LC-IRMS) became commercially available. LC-IRMS system intent a quantitative conversion of analytes separation into CO2 via wet oxidation with sodium persulfate in the presence of phosphoric acid while analytes are still dissolved in the aqueous liquid phase.[2] The aim of this study is to analyze the oxidation capacity of the interface of the LC-IRMS system and determine which parameters could improve oxidation of compounds which are resistant to persulfate oxidation. Oxidation capacity of the liquid chromatography isotope ratio mass spectrometry system was tested with halogenated acetic acid and a set of aromatic compounds with different substitutes. Acetic acid (AA) was taken as a model compound for complete oxidation and compared to the oxidation of other analytes on a molar basis. Correct values were obtained for di- and mono chlorinated and fluorinated and also for tribrominated acetic acid and for all studied aromatic compounds. Incomplete oxidation for trichloroacetic (TCAA) and trifluoroacetic (TFAA) acid was revealed with lower recovery compared to acetic acid and isotope fractionation leading to depleted carbon isotope composition compared to values obtained with an elementary analyzer connected to an isotope mass spectrometer Several optimization steps were tried in order to improve the oxidation of TCAA and TFAA: (i) increasing the concentration of the oxidizing agent, (ii) variation of flow rate of the oxidizing and acid solution, (iii) variation of flow rate of liquid chromatography pump (iv) addition of a catalyzer. These modifications lead to longer reaction time in the coil and increase in the concentration of radical but complete combustion of highly chlorinated or fluorinated compounds was not achieved. Due to these findings the limit for a LC-IRMS system for similar structure compounds can be predicted. 1. Elsner, M., et al., Current challenges in compound-specific stable isotope analysis of environmental organic contaminants. Analytical and Bioanalytical Chemistry, 2012. 403(9): p. 2471-2491. 2. Krummen, M., et al., A new concept for isotope ratio monitoring liquid chromatography/mass spectrometry. Rapid Communications in Mass Spectrometry, 2004. 18(19): p. 2260-2266.

α-Ketol linolenic acid (KODA) application affects endogenous abscisic acid, jasmonic acid and aromatic volatiles in grapes infected by a pathogen (Glomerella cingulata).

PubMed

Wang, Shanshan; Saito, Takanori; Ohkawa, Katsuya; Ohara, Hitoshi; Shishido, Masahiro; Ikeura, Hiromi; Takagi, Kazuteru; Ogawa, Shigeyuki; Yokoyama, Mineyuki; Kondo, Satoru

2016-03-15

Effects of α-ketol linolenic acid (KODA) application on endogenous abscisic acid (ABA), jasmonic acid (JA), and aromatic volatiles were investigated in 'Kyoho' grapes (Vitis labrusca×Vitis vinifera) infected by a pathogen (Glomerella cingulata). The expressions of 9-cis-epoxycarotenoid dioxygenase (VvNCED1), ABA 8'-hydroxylase (VvCYP707A1), lipoxygenase (VvLOX), and allene oxide synthase (VvAOS) were also examined. The grape berries were dipped in 0.1mM KODA solution before inoculation with the pathogen and stored at 25°C for 12 days. The development of infection was significantly suppressed upon KODA treatment. Endogenous ABA, JA and phaseic acid (PA) were induced in inoculated berries. KODA application before inoculation increased endogenous ABA, PA and JA through the activation of VvNCED1, VvCYP707A1 and VvAOS genes, respectively. In addition, terpenes, methyl salicylate (Me-SA) and C6-aldehydes such as (E)-2-hexenal and cis-3-hexenal associated with fungal resistance also increased in KODA-treated berries during storage. These results suggest that the synergistic effect of JA, ABA, and some aromatic volatiles induced by KODA application may provide resistance to pathogen infection in grape berries. Copyright © 2016 Elsevier GmbH. All rights reserved.

TEMPORAL VARIABILITY MEASUREMENT OF SPECIFIC VOLATILE ORGANIC COMPOUNDS

EPA Science Inventory

Methodology was developed to determine unambiguously trace levels of volatile organic compounds as they vary in concentration over a variety of time scales. his capability is important because volatile organic compounds (VOCs) are usually measure by time-integrative techniques th...

Advances in fruit aroma volatile research.

PubMed

El Hadi, Muna Ahmed Mohamed; Zhang, Feng-Jie; Wu, Fei-Fei; Zhou, Chun-Hua; Tao, Jun

2013-07-11

Fruits produce a range of volatile compounds that make up their characteristic aromas and contribute to their flavor. Fruit volatile compounds are mainly comprised of esters, alcohols, aldehydes, ketones, lactones, terpenoids and apocarotenoids. Many factors affect volatile composition, including the genetic makeup, degree of maturity, environmental conditions, postharvest handling and storage. There are several pathways involved in volatile biosynthesis starting from lipids, amino acids, terpenoids and carotenoids. Once the basic skeletons are produced via these pathways, the diversity of volatiles is achieved via additional modification reactions such as acylation, methylation, oxidation/reduction and cyclic ring closure. In this paper, we review the composition of fruit aroma, the characteristic aroma compounds of several representative fruits, the factors affecting aroma volatile, and the biosynthetic pathways of volatile aroma compounds. We anticipate that this review would provide some critical information for profound research on fruit aroma components and their manipulation during development and storage.

Detection of chlorinated aromatic compounds

DOEpatents

Ekechukwu, A.A.

1996-02-06

A method for making a composition for measuring the concentration of chlorinated aromatic compounds in aqueous fluids, and an optical probe for use with the method are disclosed. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis. 5 figs.

Detection of chlorinated aromatic compounds

DOEpatents

Ekechukwu, Amy A.

1996-01-01

A method for making a composition for measuring the concentration of chloated aromatic compounds in aqueous fluids, and an optical probe for use with the method. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis.

Volatile profiles of Italian monovarietal extra virgin olive oils via HS-SPME-GC-MS: newly identified compounds, flavors molecular markers, and terpenic profile.

PubMed

Cecchi, Teresa; Alfei, Barbara

2013-12-01

This study aims to contribute to the knowledge of the commercial, sensory, and analytical characteristics of extra virgin olive oil (EVOO) from Italy (Marche region), renowned since ancient times. Headspace solid-phase micro-extraction (HS-SPME) was applied for the very first time to the sampling of volatile compounds of eleven typical Italian monocultivar EVOOs. Forty-eight compounds were characterised by GC-MS, some of them were only occasionally found in other EVOOs and some other were never detected before in any EVOO. Compounds belonging mainly to alcohols, esters, aldehydes, ketones and hydrocarbons chemical classes characterised the volatile profiles. The main volatile compounds detected in the EVOOs were the C6 compounds derived from polyunsaturated fatty acids, through the lipoxygenase pathway, in different proportion according to the specific cultivar. The results suggest that genetic factors strongly influence volatile formation and terpene hydrocarbons are claimed to be suitable markers of the geographic origin and genotype of the EVOO. Correlations among sensory attributes evaluated by a panel test and the presence of specific volatile compounds were highlighted for the very first time. The significance of the presence of some newly identified volatile compounds was discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Surface microlayer enrichment of volatile organic compounds and semi-volatile organic compounds in drinking water source.

PubMed

Huang, Zhi; Zhou, Wen; Yu, Ya-juan; Zhang, Ai-qian; Han, Shuo-kui; Wang, Lian-sheng

2004-01-01

Enrichment of volatile organic compounds(VOC) and semi-volatility organic compounds(SVOC) in surface microlayer(SM) of three drinking water sources were studied. The enrichment factor(EFs) were 0.67 to 13.37 and 0.16 to 136, respectively. The results showed some VOC and most SVOC could enrich in SM. Some EFs of SVOC was quite high. Suspension and temperature could affect EFs of SVOC, slim wind and water movement do not destroy enrichment of organic in SM.

Translational diffusion coefficients of volatile compounds in various aqueous solutions at low and subzero temperatures.

PubMed

Covarrubias-Cervantes, Marco; Champion, Dominique; Debeaufort, Frédéric; Voilley, Andrée

2005-08-24

Translational diffusion coefficients (D(12)) of volatile compounds were measured in model media with the profile concentration method. The influence of sample temperature (from 25 to -10 degrees C) was studied on translational diffusion in sucrose or maltodextrin solutions at various concentrations. Results show that diffusivity of volatile compounds in sucrose solutions is controlled by temperature, molecule size, and the viscosity of the liquid phase as expected with the Stokes-Einstein equation; moreover, physicochemical interactions between volatile compounds and the medium are determinant for diffusion estimation. At negative temperature, the winding path induced by an ice crystal content of >70% lowered volatile compound diffusion. On the contrary, no influence on translational diffusion coefficients was observed for lower ice content.

Analysis of Volatile Organic Compounds Emitted by Plant Growth-Promoting Fungus Phoma sp. GS8-3 for Growth Promotion Effects on Tobacco

PubMed Central

Naznin, Hushna Ara; Kimura, Minako; Miyazawa, Mitsuo; Hyakumachi, Mitsuro

2013-01-01

We extracted volatile organic compounds (VOCs) emitted by a plant growth-promoting fungus (PGPF) Phoma sp. GS8-3 by gas chromatography and identified them by mass spectrometry. All of the identified compounds belonged to C4-C8 hydrocarbons. Volatiles varied in number and quantity by the culture period of the fungus (in days). 2-Methyl-propanol and 3-methyl-butanol formed the main components of the volatile blends for all the culture periods of fungus. Growth-promoting effects of the identified synthetic compounds were analyzed individually and in blends using tobacco plants. We found that the mixture of volatiles extracted from 3-day-old culture showed significant growth promotion in tobacco in vitro. The volatile blend showed better growth promotion at lower than higher concentrations. Our results confirm the potential role of volatile organic compounds in the mechanism of growth enhancement by GS8-3. PMID:23080408