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Sample records for profiling volatile compounds

  1. Volatile metabolite profiling reveals the changes in the volatile compounds of new spontaneously generated loquat cultivars.

    PubMed

    Besada, C; Sanchez, G; Gil, R; Granell, A; Salvador, A

    2017-10-01

    In recent years, the advantageous traits of three new loquat cultivars have drawn the attention of breeders and growers. All three have spontaneously arisen from the 'Algerie' cultivar: the new 'Xirlero' cultivar is a bud mutant of 'Algerie', while 'Amadeo' and 'Raúl' arose as chance seedlings. Following a non-targeted approach based on HS-SPME-GC-MS, the volatile compounds profile of the fruits from the new cultivars were obtained and compared to the original 'Algerie' cultivar. Carboxylic acids clearly dominated the volatile profile of all the loquat cultivars, but esters, aldehydes, ketones and alcohols were also predominant compounds. Interestingly when the bud mutant event did not lead to marked changes in the volatile compounds complement, pronounced changes in the volatile composition of chance seedling-generated cultivars 'Amadeo' and 'Raúl' were observed. 'Amadeo' fruits showed lower levels of 2-methyl butanoic acid and much higher levels of methylhexanoate, methylbutanoate and 2-hydroxy-5-methylacetophenone. The 'Raúl' cultivar also had a distinctive volatile profile characterised by high levels of C6-aldehydes, (E)-2-hexanal, 2-hexenal, (Z)-3-hexenal and hexanal, and several carotenoid-derived volatiles; e.g. 2-pentene-1,4-dione 1-(1,2,2-trimethylcyclopentyl), (S)-dihydroactinidiolide, isodurene, cis-geranyl acetone, β-damascenone, β-ionone, α-ionone and 3,4-dehydro-β-ionone. These changes in volatiles were associated with a more intense flavour in cultivars 'Amadeo' and 'Raúl', according to the sensory evaluation of the flavour intensity carried out by a semi-trained panel. A metabolomic correlation network analysis provided insights as to how volatiles were regulated, and revealed that the compounds modified in 'Amadeo' were uncoupled from the rest of the volatilome, while the volatiles modified in 'Raul' changed according to specific groups. To conclude, this work provides a holistic view of how the loquat volatilome was affected, and this

  2. Volatile organic compound emission profiles of four common arctic plants

    NASA Astrophysics Data System (ADS)

    Vedel-Petersen, Ida; Schollert, Michelle; Nymand, Josephine; Rinnan, Riikka

    2015-11-01

    The biogenic volatile organic compound (BVOC) emissions from plants impact atmosphere and climate. The species-specific emissions, and thereby the atmospheric impact, of many plant species are still unknown. Knowledge of BVOC emission from arctic plants is particularly limited. The vast area and relatively high leaf temperature give the Arctic potential for emissions that cannot be neglected. This field study aimed to elucidate the BVOC emission profiles for four common arctic plant species in their natural environment during the growing season. BVOCs were sampled from aboveground parts of Empetrum hermaphroditum, Salix glauca, Salix arctophila and Betula nana using the dynamic enclosure technique and collection of volatiles in adsorbent cartridges, analyzed by gas chromatography-mass spectrometry. Sampling occurred three times: in late June/early July, in mid-July and in early August. E. hermaphroditum emitted the least BVOCs, dominated by sesquiterpenes (SQTs) and non-isoprenoid BVOCs. The Salix spp. emitted the most, dominated by isoprene. The emissions of B. nana were composed of about two-thirds non-isoprenoid BVOCs, with moderate amounts of monoterpenes (MTs) and SQTs. The total B. nana emissions and the MT and SQT emissions standardized to 30 °C were highest in the first measurement in early July, while the other species had the highest emissions in the last measurement in early August. As climate change is expected to increase plant biomass and change vegetation composition in the Arctic, the BVOC emissions from arctic ecosystems will also change. Our results suggest that if the abundance of deciduous shrubs like Betula and Salix spp. increases at the expense of slower growing evergreens like E. hermaphroditum, there is the potential for increased emissions of isoprene, MTs and non-isoprenoid BVOCs in the Arctic.

  3. Relationship between flavour deterioration and the volatile compound profile of semi-ripened sausage.

    PubMed

    Lorenzo, José Manuel; Bedia, Mario; Bañón, Sancho

    2013-03-01

    This study provides data on the relationship between flavour deterioration and the volatile compound profile of semi-ripened pork salami kept under retail conditions for up to 150 days. The flavour of salami deteriorated for 120 days, resulting in rancidity and a loss of acceptability. TBARS increased from 0.16 to 0.57 MDA/kg. The flavour changes during the shelf life of salami were monitored from changes in the volatile profile. The retailing time influenced (p<0.05) the level of 27 of the 30 headspace volatiles determined by SPME-GC/MS. Flavour deterioration was associated with the loss and/or degradation of volatiles resulting from spices and microbial activities, and the formation of volatiles from lipid oxidation. The levels of 2-heptenal and methyl esters of heptanoic, pentanoic and hexanoic acids were the best discriminators of storage time, and therefore seem to be promising as marker compounds of flavour deterioration and acceptability.

  4. High-resolution gas chromatographic profiles of volatile organic compounds produced by microorganisms at refrigerated temperatures.

    PubMed Central

    Lee, M L; Smith, D L; Freeman, L R

    1979-01-01

    Three different strains of bacteria isolated from spoiled, uncooked chicken were grown in pure culture on Trypticase soy agar supplemented with yeast extract. The volatile organic compounds produced by each culture were concentrated on a porous polymer precolumn and analyzed by high-resolution gas chromatographic mass spectrometry. Twenty different compounds were identified. Both qualitative and quantitative differences in the chromatographic profiles from each culture were found. PMID:104660

  5. Phenotypic profiling and gene expression analyses for aromatic and volatile compounds in Chamoes (Cucumis melo).

    PubMed

    Lee, Jeongyeo; Kim, Min Keun; Hwang, Seung Hwan; Kim, Jungeun; Ahn, Jong Moon; Min, Sung Ran; Park, Sang Un; Lim, Soon Sung; Kim, HyeRan

    2014-05-01

    Gotgam chamoe (GgC), a native oriental melon in Korea, is known to possess the aroma of a dried persimmon, an agronomic relevance for melon breeding program. The volatile compounds and the transcript levels of aromatic compound genes in cultivar (Ohbokggul chamoe [OC]) and GgC were profiled. A total of 62 volatile compounds were identified and quantified. Twenty-eight volatile compounds were specific to either the OC or the GgC. The amounts of volatile alcohol, saturated hydrocarbon, and unsaturated hydrocarbon compounds were 2.2, 2.7, and 1.1 times higher in OC, respectively. The amounts of ketone volatiles were 1.2 times higher in GgC, whereas the total amounts of esters were similar. In the shikimate pathway, transcriptional patterns with the fruit parts were different between the two chamoes for CmDAHPS, CmDHD/SDH, and CmEPSPS. The expression levels of all six genes investigated, especially CmCS, were highest in the peel of both chamoes compared to the other parts. The transcript levels of the aromatic amino acid biosynthesis genes demonstrate that phenylalanine and tyrosine are present more in edible parts of the chamoe, while tryptophan may be accumulated low in the chamoe. In addition, phenylalanine and tryptophan are synthesized more in GgC than the OC.

  6. Volatile compound profile of sous-vide cooked lamb loins at different temperature-time combinations.

    PubMed

    Roldán, Mar; Ruiz, Jorge; Del Pulgar, José Sánchez; Pérez-Palacios, Trinidad; Antequera, Teresa

    2015-02-01

    Lamb loins were subjected to sous-vide cooking at different combinations of temperature (60 and 80°C) and time (6 and 24h) to assess the effect on the volatile compound profile. Major chemical families in cooked samples were aliphatic hydrocarbons and aldehydes. The volatile compound profile in sous-vide cooked lamb loin was affected by the cooking temperature and time. Volatile compounds arising from lipid oxidation presented a high abundance in samples cooked at low or moderate cooking conditions (60°C for 6 and 24h, 80°C for 6h), while a more intense time and temperature combination (80°C for 24h) resulted on a higher concentration of volatile compounds arising from Strecker degradations of amino acids, as 2-methylpropanal and 3-methylbutanal. Therefore, sous-vide cooking at moderately high temperatures for long times would result in the formation of a stronger meaty flavor and roast notes in lamb meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Volatile compounds in dry dog foods and their influence on sensory aromatic profile.

    PubMed

    Koppel, Kadri; Adhikari, Koushik; Di Donfrancesco, Brizio

    2013-02-27

    The aim of this study was to determine volatile compounds in dry dog foods and their possible influence on sensory aromatic profile. Grain-free dry dog foods were compared to dry dog foods manufactured with grain, but also with different protein sources for their aromatic volatiles. Solid-phase microextraction/gas chromatography/mass spectrometry was used to determine the aromatic compounds present in the headspace of these samples. Partial Least Squares regression was performed to correlate the instrumental aromatic data with the descriptive aroma analysis data. A total of 54 aromatic compounds were tentatively identified in the dry dog food samples, with aldehydes and ketones being the most represented organic volatiles group. Grain-added products were on the average higher in total volatiles than grain-free products. Partial Least Squares regression analysis indicated possible connections with sensory aromatic profile and grain-added samples, such as rancid aroma and aldehydes, especially hexanal. The results of this study showed that dry dog foods are products with complex odor characteristics and that grain-free products are less aromatic.

  8. Comparison of fermented soybean paste (Doenjang) prepared by different methods based on profiling of volatile compounds.

    PubMed

    Jo, Ye-Jin; Cho, In Hee; Song, Chi Kwang; Shin, Hye Won; Kim, Young-Suk

    2011-04-01

    In this study, 2 different extraction methods, namely solvent-assisted flavor evaporation (SAFE) and solid-phase microextraction (SPME), were employed to investigate the comprehensive volatile profile of Doenjang (one of Korean fermented soybean pastes) efficiently. Quantitatively, major volatiles of Doenjang isolated by SAFE were 3-methylbutanoic acid, butanoic acid, 3-hydroxy-2-methyl-4H-pyran-4-one (maltol), ethyl 2-methylbutanoate, 2-methylpropanoic acid, tetramethylpyrazine, and 4-ethyl-2-methoxyphenol, while ethanol, ethenylbenzene, ethyl benzoate, ethyl linoleate, ethyl acetate, ethyl butanoate, tetramethylpyrazine, and ethyl 2-methylpropanoate extracted by SPME. In addition, volatile profiling that applied principal component analysis to gas chromatography-mass spectrometry datasets allowed Doenjang samples that had been prepared using different traditional and commercial methods to be discriminated, and the volatile compounds that contributed to their discrimination were assigned. The major volatiles that were related to differentiation of traditional and commercial Doenjang samples were 2-pentylfuran, 4-ethylphenol, dihydro-5-methyl-2(3H)-furanone, butanoic acid, pyrazines (for example, 2-ethyl-5-methylpyrazine and 2,3-dimethylpyrazine), esters (for example, ethyl 4-methylpentanoate and diethyl succinate), maltol, dimethyl disulfide, 2- and 3-methylbutanal, hexanal, 4-vinylphenol, and ethanol.

  9. Characterization of volatile compounds and olfactory profile of red minority varietal wines from La Rioja.

    PubMed

    Martínez-Pinilla, Olga; Guadalupe, Zenaida; Ayestarán, Belén; Pérez-Magariño, Silvia; Ortega-Heras, Miriam

    2013-12-01

    The aim of this work was to study for the first time the volatile compounds and olfactory profile of La Rioja red wines made with the local varieties Vitis vinifera cv. Monastel and Maturana Tinta de Navarrete, using Tempranillo as a reference variety. The impact of vintage on these compounds was also evaluated, and chemometric techniques were applied to achieve a possible differentiation of the wines. A clear classification of wines according to grape variety and vintage was obtained. Volatile compounds that differentiated wines by grape variety were varietal aromas whereas vintage was mainly differentiated by compounds formed during the alcoholic fermentation and extracted from wood during the elaboration process in wooden barrels. Sensory analysis also allowed differentiation of wines by grape variety. Tempranillo wines were characterized by liquorice notes, whereas Maturana Tinta de Navarrete wines were the least fruity and showed herbaceous and pepper notes. The sensory profile of Monastel varied between vintages. These minor grape varieties could provide a good alternative to the most widespread variety in La Rioja: Tempranillo. The use of these varieties produced wines with their own personality and different aromatic profile from other wines on the market. © 2013 Society of Chemical Industry.

  10. Characteristics of volatile organic compounds emission profiles from hot road bitumens.

    PubMed

    Boczkaj, Grzegorz; Przyjazny, Andrzej; Kamiński, Marian

    2014-07-01

    A procedure for the investigation and comparison of volatile organic compounds (VOCs) emission profiles to the atmosphere from road bitumens with various degrees of oxidation is proposed. The procedure makes use of headspace analysis and gas chromatography with universal as well as selective detection, including gas chromatography-mass spectrometry (GC-MS). The studies revealed that so-called vacuum residue, which is the main component of the charge, contains variable VOC concentrations, from trace to relatively high ones, depending on the extent of thermal cracking in the boiler of the vacuum distillation column. The VOC content in the oxidation product, so-called oxidized paving bitumen, is similarly varied. There are major differences in VOC emission profiles between vacuum residue and oxidized bitumens undergoing thermal cracking. The VOC content in oxidized bitumens, which did not undergo thermal cracking, increases with the degree of oxidation of bitumens. The studies revealed that the total VOC content increases from about 120 ppm for the raw vacuum residue to about 1900 ppm for so-called bitumen 35/50. The amount of volatile sulfur compounds (VSCs) in the volatile fraction of fumes of oxidized bitumens increases with the degree of oxidation of bitumen and constitutes from 0.34% to 3.66% (w/w). The contribution of volatile nitrogen compounds (VNCs) to total VOC content remains constant for the investigated types of bitumens (from 0.16 to 0.28% (w/w) of total VOCs). The results of these studies can also find use during the selection of appropriate bitumen additives to minimize their malodorousness. The obtained data append the existing knowledge on VOC emission from oxidized bitumens. They should be included in reports on the environmental impact of facilities in which hot bitumen binders are used.

  11. Profiling of volatile compounds in APC(Min/+) mice blood by dynamic headspace extraction and gas chromatography/mass spectrometry.

    PubMed

    Kakuta, Shoji; Nishiumi, Shin; Yoshida, Masaru; Fukusaki, Eiichiro; Bamba, Takeshi

    2015-10-15

    Various volatile compounds as well as hydrophilic compounds exist in the blood. For example, 2-alkenals, 4-hydroxy-2-alkenals, and ketoaldehydes have been reported as oxidized lipid-derived volatiles in blood. These specific volatiles have been associated with diseases; however, multi-volatile analyses have not been performed. In this study, volatile profiling of APC(Min/+) mouse plasma by dynamic headspace extraction was performed for multi-volatile analysis. In total, 19 volatiles were detected in the plasma of mice, based on information regarding oxidized lipid-derived volatile compounds, and eight of these compounds differed significantly between normal and diseased mice. 2-Methyl-2-butanol and benzyl alcohol were previously unreported in blood samples. Furthermore, 3,5,5-trimethyl-2(5H)-furanone was only detected in normal mice. 5-Methyl-3-hexanone and benzaldehyde have been detected in subjects with gastrointestinal diseases and lung cancer, respectively. Therefore, volatile profiling can be used to detect differences between samples and to identify compounds associated with diseases.

  12. Vertical profiles and receptor modeling of volatile organic compounds over Southeastern Mexico City

    NASA Astrophysics Data System (ADS)

    Wöhrnschimmel, Henry; Márquez, Claudia; Mugica, Violeta; Stahel, Werner A.; Staehelin, Johannes; Cárdenas, Beatriz; Blanco, Salvador

    Tethered balloon flights were carried out over Southeastern Mexico City in April 2003, providing vertical profiles of ozone (0-1000 m above ground) and volatile organic compounds (VOCs, 0-200 m above ground). The objective of this study was to provide insight into the processes that drive ozone formation in Mexico City. In this paper, we discuss the atmospheric chemistry, emission sources and transport processes that influence the observed profiles. Characteristic ozone profiles were measured in the morning with the highest concentrations recorded in the residual layer. Maximum ozone concentrations, as high as 170 ppb, were measured at ground level in the afternoon. For the shape of VOC vertical profiles, no unique patterns were found. High concentrations were measured for propane, butane and toluene. Diurnal variations in VOC concentrations imply a strong effect of vertical dilution with an increasing mixing layer. Two different receptor models were used to relate observed VOC concentrations to emission sources. Results from a chemical mass balance (CMB) model suggest that the main contributors to total VOCs and the related ozone formation potential are gasoline vehicle exhaust and liquefied petroleum gas (LPG). A linear unmixing analysis reproduced satisfactorily the measured source profiles of the main sources. The relative source activities calculated by the CMB and the linear unmixing models coincide well for the LPG contribution; however, the vehicle exhaust contribution is underestimated and solvent emissions are overestimated by linear unmixing relative to the CMB model.

  13. Volatile organic compounds (VOCs) source profiles of on-road vehicle emissions in China.

    PubMed

    Hong-Li, Wang; Sheng-Ao, Jing; Sheng-Rong, Lou; Qing-Yao, Hu; Li, Li; Shi-Kang, Tao; Cheng, Huang; Li-Ping, Qiao; Chang-Hong, Chen

    2017-12-31

    Volatile Organic Compounds (VOCs) source profiles of on-road vehicles were widely studied as their critical roles in VOCs source apportionment and abatement measures in megacities. Studies of VOCs source profiles from on-road motor vehicles from 2001 to 2016 were summarized in this study, with a focus on the comparisons among different studies and the potential impact of different factors. Generally, non-methane hydrocarbons dominated the source profile of on-road vehicle emissions. Carbonyls, potential important components of vehicle emission, were seldom considered in VOCs emissions of vehicles in the past and should be paid more attention to in further study. VOCs source profiles showed some variations among different studies, and 6 factors were extracted and studied due to their impact to VOCs source profile of on-road vehicles. Vehicle types, being dependent on engine types, and fuel types were two dominant factors impacting VOCs sources profiles of vehicles. In comparison, impacts of ignitions, driving conditions and accumulated mileage were mainly due to their influence on the combustion efficiency. An opening and interactive database of VOCs from vehicle emissions was critically essential in future, and mechanisms of sharing and inputting relative research results should be formed to encourage researchers join the database establishment. Correspondingly, detailed quality assurance and quality control procedures were also very important, which included the information of test vehicles and test methods as detailed as possible. Based on the community above, a better uncertainty analysis could be carried out for the VOCs emissions profiles, which was critically important to understand the VOCs emission characteristics of the vehicle emissions. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. The profile in polyphenols and volatile compounds in alcoholic beverages from different cultivars of mulberry.

    PubMed

    Juan, Chen; Jianquan, Kan; Junni, Tang; Zijian, Cai; Ji, Liu

    2012-04-01

    Mulberry fruits have different chemical compositions because of cultivar variation. In this study, polyphenol profile and volatile composition of alcoholic beverages produced from different mulberries of Da 10, Hongguo 2 hao, and Hongguo 1 hao were investigated. Statistically significant differences were detected in the chemical composition of the analyzed alcoholic beverage samples. The beverage of Da 10 possessed the highest content of total phenols, total flavonoids, and total anthocyanins, which was determined by spectrophotometry analysis, contrarily Hongguo 1 hao beverage showing the lowest. Phenolic acids and flavonols were analyzed by high performance liquid chromatography analysis. Protocatechuic acid was the main phenolic acid in all analyzed alcoholic beverage samples, and its concentration ranged from 8.20 mg L⁻¹ (Hongguo 1 hao beverage) to 29.98 mg L⁻¹ (Da 10 beverage). High level of flavonols was found in both Da 10 and Hongguo 2 hao beverage samples, whereas Hongguo 1 hao beverage sample was characterized with lower level of flavonols. Furthermore, volatile compounds were analyzed by solid phase microextraction-gas chromatography mass spectrometry analysis. The amount of esters varied widely among the 3 alcoholic beverage samples. The concentration of aliphatic alcohols in Hongguo 2 hao and 1 hao beverage samples was higher than Da 10 sample, whereas Da 10 beverage sample contained more aromatic alcohols than the others. Hongguo 1 beverage sample showed the highest concentration of acetic acid. This study demonstrated that quantitative differences of phenolic compounds and volatile compounds among cultivars were significant, which highly affected the quality of alcoholic beverage from mulberry. Mulberry fruits had different chemical compositions because of cultivar variation. The analyzed Da 10 cultivar of mulberry appeared to be a good raw material for alcoholic beverage-making because of its high level of total sugar and acidity. This study

  15. Volatile compounds in light, medium, and dark black walnut and their influence on the sensory aromatic profile.

    PubMed

    Lee, Jeehyun; Vázquez-Araújo, Laura; Adhikari, Koushik; Warmund, Michele; Elmore, Janelle

    2011-03-01

    Light, medium, and dark colored kernels from 3 different cultivars (Emma K, Kwik Krop, and Sparks 127) and one wild species of black walnut were studied for their aroma volatiles. Solid-phase microextraction-gas chromatography-mass spectrometry was used to determine the aromatic compounds present in the headspace of these samples. Partial least square regression was used to correlate the instrumental aromatic data with the sensory responses, obtained in a previous study, for the same samples. Thirty-four aromatic compounds were found in the black walnut cultivars, highlighting among them the presence of 14 esters. Although more than 50% of the total concentration of volatile compounds, esters were not important compounds in determining the differences in the sensory aromatic profiles of the 3 colors of the nuts. As a general trend, the concentration of total volatile compounds was always significantly higher in light black walnuts than in the medium colored samples; medium colored samples had higher volatile content than the dark black walnuts. The presence of hexanal was related to rancid and acrid aromas and was determined to differentiate the dark black walnuts from the medium and light colored samples. The data presented in this article will help understand the aromatic differences between light, medium, and dark colored kernels of domestic and wild black walnut. The aromatic profile of these nuts, not studied until this moment, can be used as a model to develop flavorings and new products by the food industries.

  16. 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.

  17. 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.

  18. Volatile organic compounds profile during milk fermentation by Lactobacillus pentosus and correlations between volatiles flavor and carbohydrate metabolism.

    PubMed

    Pan, D D; Wu, Z; Peng, T; Zeng, X Q; Li, H

    2014-02-01

    Flavor, as one of the most important properties determining the acceptability and preference of fermented milks, is influenced by compositional and processing factors. In this study, we focused on the volatile organic compounds related to flavor during milk fermentation by Lactobacillus pentosus according to electronic nose analysis. Xylose (1% addition) metabolized by Lb. pentosus strongly affects the flavor of yogurt, with the potent volatile organic compounds of ethanol (3.08%), 2,3-butanedione (7.77%), and acetic acid (22.70%) detected using solid-phase microextraction coupled with gas chromatography-mass spectrometry analysis. Sensoryanalysis also showed skimmed yogurt fermented by Lb. pentosus with 1% xylose had the unique scores of sourness (acetic acid) and butter flavor (2,3-butanedione). Furthermore, α-acetolactate synthase and α-acetolactate decarboxylase in carbohydrate metabolism play important roles in milk fermentation. Under preferable conditions (pH 5.5, 42 °C) for α-acetolactate synthase and α-acetolactate decarboxylase, the relative content of potent flavor compound 2,3-butanedione was 10.13%, which was 2.55% higher than common culture condition (pH 4.5, 37 °C), revealing that xylose metabolized by Lb. pentosus has potential values for the milk product industry, such as the acceptability and preference of fermented milk product.

  19. Blood and breath profiles of volatile organic compounds in patients with end-stage renal disease

    PubMed Central

    2014-01-01

    Background Monitoring of volatile organic compounds (VOCs) in exhaled breath shows great potential as a non-invasive method for assessing hemodialysis efficiency. In this work we aim at identifying and quantifying of a wide range of VOCs characterizing uremic breath and blood, with a particular focus on species responding to the dialysis treatment. Methods Gas chromatography with mass spectrometric detection coupled with solid-phase microextraction as pre-concentration method. Results A total of 60 VOCs were reliably identified and quantified in blood and breath of CKD patients. Excluding contaminants, six compounds (isoprene, dimethyl sulfide, methyl propyl sulfide, allyl methyl sulfide, thiophene and benzene) changed their blood and breath levels during the hemodialysis treatment. Conclusions Uremic breath and blood patterns were found to be notably affected by the contaminants from the extracorporeal circuits and hospital room air. Consequently, patient exposure to a wide spectrum of volatile species (hydrocarbons, aldehydes, ketones, aromatics, heterocyclic compounds) is expected during hemodialysis. Whereas highly volatile pollutants were relatively quickly removed from blood by exhalation, more soluble ones were retained and contributed to the uremic syndrome. At least two of the species observed (cyclohexanone and 2-propenal) are uremic toxins. Perhaps other volatile substances reported within this study may be toxic and have negative impact on human body functions. Further studies are required to investigate if VOCs responding to HD treatment could be used as markers for monitoring hemodialysis efficiency. PMID:24607025

  20. Screening of variety- and pre-fermentation-related volatile compounds during ripening of white grapes to define their evolution profile.

    PubMed

    Coelho, Elisabete; Rocha, Sílvia M; Barros, António S; Delgadillo, Ivonne; Coimbra, Manuel A

    2007-08-06

    The variety- and pre-fermentation-related volatile compounds of 'Fernão-Pires' (FP) white grape berries were analyzed during ripening by headspace-solid phase microextraction (HS-SPME) coupled to gas chromatography-quadrupole mass spectrometry (GC-qMS). A preliminary step, in which the grapes were crushed and macerated before HS-SPME analyses, was used. The sampling started at véraison (beginning of berry ripening) and was carried on during 5 weeks in two different vineyards. Sixteen terpenoids, two C13 norisoprenoids, two aromatic alcohols, two C6 aldehydes, and three C6 alcohols were identified. The amount of all volatiles increased since véraison towards day 20. A sharp decrease was observed after this day. The maximum amount of varietal volatile compounds was coincident with the harvesting day for white table wine production defined by the ratio sugar/acid content. The varietal volatile evolution observed for FP grapes shows that the maximum amount of volatiles occurs only in a very short period. As a consequence, the establishment of the optimum moment for harvesting of FP white variety, based on its volatile content, deserves higher accuracy than that necessary for all other already studied grapes. This work also evidences that the analysis of the evolution of the terpenoids with higher GC peak area can represent the evolution of all varietal compounds. For FP grapes, this work shows that the screening of linalool, alpha-terpineol, and geraniol during ripening can be used to define the evolution profile of the varietal volatile compounds.

  1. Influence of age and gender on the profile of exhaled volatile organic compounds analyzed by an electronic nose

    PubMed Central

    Dragonieri, Silvano; Quaranta, Vitaliano Nicola; Carratu, Pierluigi; Ranieri, Teresa; Resta, Onofrio

    2016-01-01

    We aimed to investigate the effects of age and gender on the profile of exhaled volatile organic compounds. We evaluated 68 healthy adult never-smokers, comparing them by age and by gender. Exhaled breath samples were analyzed by an electronic nose (e-nose), resulting in "breathprints". Principal component analysis and canonical discriminant analysis showed that older subjects (≥ 50 years of age) could not be distinguished from younger subjects on the basis of their breathprints, as well as that the breathprints of males could not distinguished from those of females (cross-validated accuracy, 60.3% and 57.4%, respectively).Therefore, age and gender do not seem to affect the overall profile of exhaled volatile organic compounds measured by an e-nose. PMID:27167436

  2. Sensory characteristics and related volatile flavor compound profiles of different types of whey.

    PubMed

    Gallardo-Escamilla, F J; Kelly, A L; Delahunty, C M

    2005-08-01

    To characterize the flavor of liquid whey, 11 samples of whey representing a wide range of types were sourced from cheese and casein-making procedures, either industrial or from pilot-plant facilities. Whey samples were assessed for flavor by descriptive sensory evaluation and analyzed for headspace volatile composition by proton transfer reaction-mass spectrometry (PTR-MS). The sensory data clearly distinguished between the samples in relation to the processes of manufacture; that is, significant differences were apparent between cheese, rennet, and acid wheys. For Mozzarella and Quarg wheys, in which fermentation progressed to low pH values, the starter cultures used for cheese making had a significant influence on flavor. In comparison, Cheddar and Gouda wheys were described by milk-like flavors, and rennet casein wheys were described by "sweet" (oat-like and "sweet") and thermally induced flavors. The volatile compound data obtained by PTR-MS differentiated the samples as distinctive and reproducible "chemical fingerprints". On applying partial least squares regression to determine relationships between sensory and volatile composition data, sensory characteristics such as "rancid" and cheese-like odors and "caramelized milk," yogurt-like, "sweet," and oat-like flavors were found to be related to the presence and absence of specific volatile compounds.

  3. Effect of a fungal infection on the profile of volatile organic compounds emitted by plant roots.

    PubMed

    Fiers, M; Lognay, G; Wathelet, J P; Fauconnier, M L; Jijakli, M H

    2012-01-01

    It is known since few years that the aerial and underground parts of the plants emit volatile organic compounds (VOCs) that can interact with other organisms of the environment. They are involved in the attraction of seed dispersers and pollinators, the repellence of enemies via direct or indirect mechanisms and the induction of defence systems in other parts of the same plant or in other plants in the vicinity (Dudareva et al., 2006). It has been shown previously that the VOCs spectrum emitted by plants hardly depends on their physiological state (Kant et al., 2009). However those phenomenons were poorly studied at the edaphic level. Thus, the Rhizovol project, a multidisciplinary project in Gembloux Agro-Bio Tech was set up to study the emissions of VOCs by plant roots and their interactions with other organisms of the rhizosphere. As a partner of this project, the Plant Pathology Unit of Gembloux Agro-Bio Tech chose to study the effect of a fungal infection on the profile of VOCs emitted by plant roots, based on three model organisms, barley (Hordeum vulgare L.), since it is a major crop in Belgium that can suffer a large range of aggressions, and two pathogenic fungi, Cochliobolus sativus and Fusarium culmorum, responsible for root and foot rots and seedling blight on cereals (Wiese, 1977). Later in the development, C. sativus produces elongate brown-black lesions (spot blotch) and F. culmorum induces head blight and produces mycotoxins that make the grain unsuitable for consumption (Nielsen et al., 2011). The objective of this work was to identify the VOCs emitted during the dual interactions between barley roots and a pathogenic fungus. The study was performed in two steps; first, the independent analyses of the VOCs emitted by each of the partners (C. sativus, F. culmorum and healthy barley roots), then the analyses of the VOCs spectrum emitted during dual interactions.

  4. Effects of including silage in the diet on volatile compound profiles in Montasio cheese and their modification during ripening.

    PubMed

    Stefanon, Bruno; Procida, Giuseppe

    2004-02-01

    Effects of including silage in the diet on volatile compound profiles and their modification during ripening of Montasio cheeses were examined. Twelve farms were selected and grouped according the type of forage in the ration: hay-based diets (four farms); hay and corn silage-based diets (four farms); and diets based on hay, corn silage and grass silages (four farms). For cheesemaking, 1000 kg of milk collected from two consecutive milkings was sampled from each farm and processed in the same cheese factory. Cheeses were ripened in the same cellar, in controlled humidity (78-85% relative humidity) and temperature (9-12 degrees C), until analysis. After 68 (62-74), 200 (194-206) and 360 (354-366) d of ripening, a cheese from each batch was analysed for moisture, protein and fat, volatile fatty acids (VFA) and volatile compounds. These latter were analysed by dynamic reverse carrier gas headspace gas chromatographic mass spectrometry (GC-MS) technique, scanning from m/z 29 to m/z 300 at 0.5 s cycle time. Total and individual VFA contents of cheeses did not differ between the different dietary treatments and increased linearly (P<0.01) during ripening, indicating that there were no appreciable defects of fermentation. Sixty-two volatile compounds were identified in the cheese samples: 12 aldehydes, 9 ketones, 16 alcohols, 17 esters, 2 hydrocarbons, 4 sulphur-containing compounds and 2 terpenes. Diet significantly affected the amount of total alcohols, ethanol, isobutanol, 1-penten-3-ol, 2-methyl-1-butanol and the sum of all the volatile compounds. Significant variations of 33 volatile compounds (9 aldehydes, 4 ketones, 6 alcohols, 10 esters, 1 hydrocarbons, 2 sulphur containing compounds, and 1 terpene) were observed during ripening. These results suggest that the influence of diet composition on volatile compounds of matured cheeses are related more to effects on microbial and chemical fermentations in cheese during ripening rather than to a direct transfer of

  5. Aroma characteristic and volatile profiling of carrot varieties and quantitative role of terpenoid compounds for carrot sensory attributes.

    PubMed

    Fukuda, Tomohiko; Okazaki, Keiki; Shinano, Takuro

    2013-11-01

    The aroma characteristics and volatile profiles of 14 carrot varieties were investigated by sensory evaluations and gas chromatography-mass spectrometry volatile analyses. The sensory map obtained by principal components analysis showed that the sensory attributes comprised 3 categories: sour/green, overall carrot/harsh/ink-like, and fruity/fresh/sweet. The Kuroda type is characterized by lower intensities of overall carrot/harsh/ink-like and fruity/fresh/sweet notes. Furthermore, volatile profiling indicated that this type did not have significantly higher amounts of volatiles. Partial least squares regression analysis determined the quantitative contributions to ink-like, harsh, and fruity carrot aromas; monoterpenes had significant positive correlations with these attributes, while bisabolene isomers had negative correlations. The aroma attribute intensity and contents of volatiles and nutritional compounds are relatively low in the Kuroda type than in other carrot types. This type may be useful for reducing carrot harshness during the development of new carrots with good eating qualities. © 2013 Institute of Food Technologists®

  6. Chemical and sensory profiles of makgeolli, Korean commercial rice wine, from descriptive, chemical, and volatile compound analyses.

    PubMed

    Jung, Heeyong; Lee, Seung-Joo; Lim, Jeong Ho; Kim, Bum Keun; Park, Kee Jai

    2014-01-01

    The chemical and sensory profiles of 12 commercial samples of makgeolli, a Korean rice wine, were determined using descriptive sensory, chemical, and volatile components analyses. The sample wines were analysed for their titratable acidity, ethanol content, pH, Hunter colour value and total reducing sugars. The chemical compositions of the makgeolli samples were found to be significantly different. The volatile compounds were extracted with solid-phase microextraction and analysed by gas chromatography time-of-flight mass spectrometry. In all, 45 major volatile compounds, consisting of 33 esters, 8 alcohols, 1 aldehyde, 1 acid, 1 phenol and 1 terpene, were identified; each makgeolli sample included 28-35 volatile compounds. Based on principal component analysis of the sensory data, samples RW1, RW2, RW5, RW8 and RW12 were associated with roasted cereal, mouldy, bubbles, sweet and sour attributes; the other samples were associated with sensory attributes of yellowness, yeast, full body, turbidity, continuation, swallow, alcohol, fruit aroma and whiteness.

  7. Effect of drying method on volatile compounds, phenolic profile and antioxidant capacity of guava powders.

    PubMed

    Nunes, Juliana C; Lago, Mabel G; Castelo-Branco, Vanessa N; Oliveira, Felipe R; Torres, Alexandre Guedes; Perrone, Daniel; Monteiro, Mariana

    2016-04-15

    We studied the chemical composition of oven and freeze dried guava powders for future use as antioxidant-rich flavour enhancers. Among thirty-one volatiles in guava powders, terpenes were predominant, even after both drying processes. In contrast, esters and aldehydes, volatiles characteristic of fresh guava fruit, appeared to have been decreased by drying. Insoluble phenolics were predominant and among the sixteen compounds identified, quercetin-3-O-rutinoside and naringenin corresponded to 56% of total phenolics. Drying processes decreased total phenolics contents by up to 44%. Oven drying promoted the release of insoluble flavonoids, generating mainly quercetin. Antioxidant capacity also decreased due to both drying processes, but guava powders still presented similar antioxidant capacity in comparison to other tropical fruit powders. Our results suggest that oven drying is a viable option for the production of a functional ingredient that would improve the phenolic content of cereal foods while adding desirable guava flavour.

  8. Evaluation of Penicillium expansum for growth, patulin accumulation, nonvolatile compounds and volatile profile in kiwi juices of different cultivars.

    PubMed

    Wang, Yuan; Shan, Tingting; Yuan, Yahong; Zhang, Zhiwei; Guo, Chunfeng; Yue, Tianli

    2017-08-01

    Patulin (PAT) contamination and changes of nonvolatile and volatile compounds caused by Penicillium expansum in fresh juices of 8 kiwi cultivars were investigated. Growth and PAT production of P. expansum were greater at 25°C than at 4°C. P. expansum grew in kiwi juices under pH ranging from 2.75 to 3.27 and produced 45.10-268.88μg/mL of PAT at 25°C. Decreases occurred in malic acid and soluble protein; while consumption and production simultaneously happened for reducing sugar, total soluble solid, titratable acid, citric acid, ascorbic acid and total phenolics. A large number of volatile organic compounds (VOCs) were produced during infection and each cultivar presented a distinct profile. Most of the alcohols, acids, ketones and phenols increased while aldehydes decreased. VOCs that were specific to infected kiwi juices are potential biomarkers for GC-MS analysis of kiwifruit infected by P. expansum.

  9. Modification of volatile compound profile of virgin olive oil due to hot-water treatment of olive fruit.

    PubMed

    Pérez, Ana G; Luaces, Pilar; Ríos, José J; García, José M; Sanz, Carlos

    2003-10-22

    The effect of hot-water treatments of olive fruits before processing on the biosynthesis of virgin olive oil aroma was investigated by quantifying the variation within the major classes of volatile compounds. Data showed that hot-water treatments gave rise to changes in the volatile aroma profile of virgin olive oil from the three olive cultivars under study, Manzanilla, Picual, and Verdial. Different effects by thermal treatments were observed according to cultivar. In general, these changes are mainly due to a decrease in the contents of C(6) aldehydes and C(5) compounds. Contents of C(6) alcohols and esters remained constant or decreased slightly when the temperature of the treatment was increased. Thus, heat treatments seemed to promote a partial deactivation of the lipoxygenase/hydroperoxide lyase enzyme system, whereas other enzymatic activities, within the lipoxygenase pathway, such as alcohol dehydrogenase and alcohol acyltransferase, remained apparently unaffected as a consequence of heat treatments.

  10. Species profiles and normalized reactivity of volatile organic compounds from gasoline evaporation in China

    NASA Astrophysics Data System (ADS)

    Zhang, Yanli; Wang, Xinming; Zhang, Zhou; Lü, Sujun; Shao, Min; Lee, Frank S. C.; Yu, Jianzhen

    2013-11-01

    In China, fast increase in passenger cars and gasoline consumption with yet quite limited vapor recovery during gasoline distribution has procured growing concern about gasoline evaporation as an important emission source of volatile organic compounds (VOCs), particularly in megacities hard-hit by air quality problems. This study presents VOC species profiles related to major pathways of gasoline evaporative loss in China, including headspace displacement, refueling operations and spillage/leakage. Apart from liquid gasoline and headspace vapors, gasoline vapors emitted when refueling cars in service stations or tank trucks in oil marketing depots were also sampled in situ with vapor recovery units (VRUs) turning on/off. Alkanes, alkenes and aromatic hydrocarbons accounted for 55-66, 21-35 and 4-8% in refueling vapors, 59-72, 18-28 and 4-10% in headspace vapors and 33-51, 8-15 and 38-48% in liquid gasoline samples, respectively. During refueling with VRUs turning on, total VOCs in vapors were less than one fifth of that with VRUs turning off, and aromatic hydrocarbons had higher weight percentages of about 8% in contrast with that of about 4% during refueling with VRUs turning off. Refueling vapors, especially for that with VRUs turning off, showed a larger fraction of light hydrocarbons including C3-C5 light alkenes when compared to headspace vapors, probably due to splashing and disturbance during filling operation. In refueling or headspace vapors the ratios of i-pentane/benzene, i-pentane/toluene, and MTBE (methyl tert-butyl ether)/benzene ranged 8.7-57, 2.7-4.8, and 1.9-6.6, respectively; and they are distinctively much higher than those previously reported in vehicle exhausts. Calculated normalized reactivity or ozone formation potential of the gasoline vapors in China ranged 3.3-4.4 g O3 g-1 VOC, about twice that of gasoline headspace vapors reported in USA as a result of larger fractions of alkenes in China's gasoline vapors. The results suggested that

  11. Impacts of simulated herbivory on volatile organic compound emission profiles from coniferous plants

    NASA Astrophysics Data System (ADS)

    Faiola, C. L.; Jobson, B. T.; VanReken, T. M.

    2015-01-01

    The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsuga menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate (MeJA), a herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC-MS-FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.

  12. Impacts of simulated herbivory on volatile organic compound emission profiles from coniferous plants

    DOE PAGES

    Faiola, C. L.; Jobson, B. T.; VanReken, T. M.

    2015-01-28

    The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsuga menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate (MeJA), a herbivory proxy. Gas-phase species were measured continuously with a gasmore » chromatograph coupled to a mass spectrometer and flame ionization detector (GC–MS–FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. Here, the compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.« less

  13. Effects of high hydrostatic pressure and thermal processing on bioactive compounds, antioxidant activity, and volatile profile of mulberry juice.

    PubMed

    Wang, Fan; Du, Bao-Lei; Cui, Zheng-Wei; Xu, Li-Ping; Li, Chun-Yang

    2017-03-01

    The aim of this study was to investigate the effects of high hydrostatic pressure and thermal processing on microbiological quality, bioactive compounds, antioxidant activity, and volatile profile of mulberry juice. High hydrostatic pressure processing at 500 MPa for 10 min reduced the total viable count from 4.38 log cfu/ml to nondetectable level and completely inactivated yeasts and molds in raw mulberry juice, ensuring the microbiological safety as thermal processing at 85 ℃ for 15 min. High hydrostatic pressure processing maintained significantly (p < 0.05) higher contents of total phenolic, total flavonoid and resveratrol, and antioxidant activity of mulberry juice than thermal processing. The main volatile compounds of mulberry juice were aldehydes, alcohols, and ketones. High hydrostatic pressure processing enhanced the volatile compound concentrations of mulberry juice while thermal processing reduced them in comparison with the control. These results suggested that high hydrostatic pressure processing could be an alternative to conventional thermal processing for production of high-quality mulberry juice.

  14. Influence of partial replacement of NaCl with KCl on profiles of volatile compounds in dry-cured bacon during processing

    USDA-ARS?s Scientific Manuscript database

    This study investigated the influence of partial substitution of NaCl with KCl on the formation of volatile compounds in bacons during processing using a purge and trap dynamic headspace GC/MS system. Three substitutions were 0% KCl (I), 40% KCl (II), and 70% KCl (III). The profiles of the volatile ...

  15. Profiling analysis of volatile compounds from fruits using comprehensive two-dimensional gas chromatography and image processing techniques.

    PubMed

    Schmarr, Hans-Georg; Bernhardt, Jörg

    2010-01-22

    An image processing approach originating from the proteomics field has been transferred successfully to the processing of data obtained with comprehensive two-dimensional gas chromatographic separations data. The approach described here has proven to be a useful analytical tool for unbiased pattern comparison or profiling analyses, as demonstrated with the differentiation of volatile patterns ("aroma") from fruits such as apples, pears, and quince fruit. These volatile patterns were generated by headspace solid phase microextraction coupled to comprehensive two-dimensional gas chromatography (HS-SPME-GC x GC). The data obtained from GC x GC chromatograms were used as contour plots which were then converted to gray-scale images and analyzed utilizing a workflow derived from 2D gel-based proteomics. Run-to-run variations between GC x GC chromatograms, respectively their contour plots, have been compensated by image warping. The GC x GC images were then merged into a fusion image yielding a defined and project-wide spot (peak) consensus pattern. Within detected spot boundaries of this consensus pattern, relative quantities of the volatiles from each GC x GC image have been calculated, resulting in more than 700 gap free volatile profiles over all samples. These profiles have been used for multivariate statistical analysis and allowed clustering of comparable sample origins and prediction of unknown samples. At present state of development, the advantage of using mass spectrometric detection can only be realized by data processing off-line from the identified software packages. However, such information provides a substantial basis for identification of statistically relevant compounds or for a targeted analysis. Copyright 2009 Elsevier B.V. All rights reserved.

  16. [Source profile and chemical reactivity of volatile organic compounds from vehicle exhaust].

    PubMed

    Qiao, Yue-Zhen; Wang, Hong-Li; Huang, Cheng; Chen, Chang-Hong; Su, Lei-Yan; Zhou, Min; Xu, Hua; Zhang, Gang-Feng; Chen, Yi-Ran; Li, Li; Chen, Ming-Hua; Huang, Hai-Ying

    2012-04-01

    Light-duty gasoline taxis (LDGT) and passenger cars (LDGV), heavy-duty diesel buses (HDDB) and trucks (HDDT), gasoline motorcycles (MC) and LPG scooters (LPGS), were selected for tailpipe volatile organic compounds (VOCs) samplings by using transient dynamometer and on road test combined with SUMMA canisters technology. The samples were tested by GC-MS to analyze the concentration and species composition of VOCs. The results indicate that light-duty gasoline automobiles have higher fractions of aromatic hydrocarbons, which account for 43.38%-44.45% of the total VOCs, the main aromatic hydrocarbons are toluene and xylenes. Heavy-duty diesel vehicles have higher fractions of alkanes, which constitute 46.86%-48.57% of the total VOCs, the main alkanes are propane, n-dodecane and n-undecane. In addition, oxy-organics account for 13.28%-15.01% of the VOCs, the main oxy-organics is acetone. The major compound from MC and LPGS exhaust is acetylene, it accounts for 39.75% and 76.67% of the total VOCs, respectively. VOCs exhaust from gasoline motorcycles and light-duty gasoline automobiles has a significantly higher chemical reactivity than those from heavy-duty diesel vehicles, which contribute 55% and 44% to the atmospheric chemical reactivity in Shanghai. The gasoline motorcycles and light-duty gasoline automobiles are the key pollution sources affecting city and region ambient oxidation, and the key active species of toluene, xylenes, propylene, and styrene make the greatest contribution.

  17. Preliminary assessment of a model to predict mold contamination based on microbial volatile organic compound profiles.

    PubMed

    LeBouf, Ryan F; Schuckers, Stephanie A; Rossner, Alan

    2010-08-01

    Identification of mold growth based on microbial volatile organic compounds (MVOCs) may be a viable alternative to current bioaerosol assessment methodologies. A feed-forward back propagation (FFBP) artificial neural network (ANN) was developed to correlate MVOCs with bioaerosol levels in built environments. A cross-validation MATLAB script was developed to train the ANN and produce model results. Entech Bottle-Vacs were used to collect chemical grab samples at 10 locations in northern NY during 17 sampling periods from July 2006 to August 2007. Bioaerosol samples were collected concurrently with chemical samples. An Anderson N6 impactor was used in conjunction with malt extract agar and dichloran glycerol 18 to collect viable mold samples. Non-viable samples were collected with Air-O-Cell cassettes. Chemical samples and bioaerosol samples were used as model inputs and model targets, respectively. Previous researchers have suggested the use of MVOCs as indicators of mold growth without the use of a pattern recognition program limiting their success. The current proposed strategy implements a pattern recognition program making it instrumental for field applications. This paper demonstrates that FFBP ANN may be used in conjunction with chemical sampling in built environments to predict the presence of mold growth.

  18. Nutritional composition, bioactive compounds and volatile profile of cocoa beans from different regions of Cameroon.

    PubMed

    Caprioli, Giovanni; Fiorini, Dennis; Maggi, Filippo; Nicoletti, Marcello; Ricciutelli, Massimo; Toniolo, Chiara; Prosper, Biapa; Vittori, Sauro; Sagratini, Gianni

    2016-06-01

    Analysis of the complex composition of cocoa beans provides fundamental information for evaluating the quality and nutritional aspects of cocoa-based food products, nutraceuticals and supplements. Cameroon, the world's fourth largest producer of cocoa, has been defined as "Africa in miniature" because of the variety it habitats. In order to evaluate the nutritional characteristics of cocoa beans from five different regions of Cameroon, we studied their polyphenolic content, volatile compounds and fatty acids composition. The High Performance Thin Layer Chromatography (HPTLC) analysis showed that the Mbalmayo sample had the highest content of theobromine (11.6 mg/g) and caffeic acid (2.1 mg/g), while the Sanchou sample had the highest level of (-)-epicatechin (142.9 mg/g). Concerning fatty acids, the lowest level of stearic acid was found in the Mbalmayo sample while the Bertoua sample showed the highest content of oleic acid. Thus, we confirmed that geographical origin influences the quality and nutritional characteristics of cocoa from these regions of Cameroon.

  19. Texture profile and volatile compound analyses of ‘Koshihikari’ and ‘Basmati’ rice prepared in different rice cookers

    USDA-ARS?s Scientific Manuscript database

    ‘Koshihikari’ and ‘Basmati’, two premium rices from Japan and India, respectively, were evaluated for volatile compounds and textural characteristics using three different cooking methods. Samples were analyzed for hardness, adhesiveness, and cohesiveness using the Texture Analyzer and for volatiles...

  20. Dynamic profiles of volatile organic compounds in exhaled breath as determined by a coupled PTR-MS/GC-MS study.

    PubMed

    King, J; Mochalski, P; Kupferthaler, A; Unterkofler, K; Koc, H; Filipiak, W; Teschl, S; Hinterhuber, H; Amann, A

    2010-09-01

    In this phenomenological study we focus on dynamic measurements of volatile organic compounds (VOCs) in exhaled breath under exercise conditions. An experimental setup efficiently combining breath-by-breath analyses using proton transfer reaction mass spectrometry (PTR-MS) with data reflecting the behaviour of major hemodynamic and respiratory parameters is presented. Furthermore, a methodology for complementing continuous VOC profiles obtained by PTR-MS with simultaneous SPME/GC-MS measurements is outlined. These investigations aim at evaluating the impact of breathing patterns, cardiac output or blood pressure on the observed breath concentration and allow for the detection and identification of several VOCs revealing characteristic rest-to-work transitions in response to variations in ventilation or perfusion. Examples of such compounds include isoprene, methyl acetate, butane, DMS and 2-pentanone. In particular, both isoprene and methyl acetate exhibit a drastic rise in concentration shortly after the onset of exercise, usually by a factor of about 3-5 within approximately 1 min of pedalling. These specific VOCs might also be interpreted as potentially sensitive indicators for fluctuations of blood or respiratory flow and can therefore be viewed as candidate compounds for future assessments of hemodynamics, pulmonary function and gas exchange patterns via observed VOC behaviour.

  1. Genetic analysis of plant endophytic Pseudomonas putida BP25 and chemo-profiling of its antimicrobial volatile organic compounds.

    PubMed

    Sheoran, Neelam; Valiya Nadakkakath, Agisha; Munjal, Vibhuti; Kundu, Aditi; Subaharan, Kesavan; Venugopal, Vibina; Rajamma, Suseelabhai; Eapen, Santhosh J; Kumar, Aundy

    2015-04-01

    Black pepper associated bacterium BP25 was isolated from root endosphere of apparently healthy cultivar Panniyur-5 that protected black pepper against Phytophthora capsici and Radopholus similis - the major production constraints. The bacterium was characterized and mechanisms of its antagonistic action against major pathogens are elucidated. The polyphasic phenotypic analysis revealed its identity as Pseudomonas putida. Multi locus sequence typing revealed that the bacterium shared gene sequences with several other isolates representing diverse habitats. Tissue localization assays exploiting green fluorescence protein expression clearly indicated that PpBP25 endophytically colonized not only its host plant - black pepper, but also other distantly related plants such as ginger and arabidopsis. PpBP25 colonies could be enumerated from internal tissues of plants four weeks post inoculation indicated its stable establishment and persistence in the plant system. The bacterium inhibited broad range of pathogens such as Phytophthora capsici, Pythium myriotylum, Giberella moniliformis, Rhizoctonia solani, Athelia rolfsii, Colletotrichum gloeosporioides and plant parasitic nematode, Radopholus similis by its volatile substances. GC/MS based chemical profiling revealed presence of Heneicosane; Tetratetracontane; Pyrrolo [1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl); Tetracosyl heptafluorobutyrate; 1-3-Eicosene, (E)-; 1-Heneicosanol; Octadecyl trifluoroacetate and 1-Pentadecene in PpBP25 metabolite. Dynamic head space GC/MS analysis of airborne volatiles indicated the presence of aromatic compounds such as 1-Undecene;Disulfide dimethyl; Pyrazine, methyl-Pyrazine, 2,5-dimethyl-; Isoamyl alcohol; Pyrazine, methyl-; Dimethyl trisulfide, etc. The work paved way for profiling of broad spectrum antimicrobial VOCs in endophytic PpBP25 for crop protection.

  2. Volatile compounds in milled/unmilled Queso Fresco during storage

    USDA-ARS?s Scientific Manuscript database

    The profile of volatile compounds that contribute to the flavor of Queso Fresco (QF), a popular high-moisture Hispanic-style cheese, is not well defined. The effects of curd milling on the volatile compounds in QF were determined for cheeses aged at 4 deg C for up to 8 wks. Volatiles from preheate...

  3. Seasonal variation in volatile compound profiles of preen gland secretions of the dark-eyed junco (Junco hyemalis).

    PubMed

    Soini, Helena A; Schrock, Sara E; Bruce, Kevin E; Wiesler, Donald; Ketterson, Ellen D; Novotny, Milos V

    2007-01-01

    Quantitative stir bar sorptive extraction methodology, followed by gas chromatography-mass spectrometry (GC-MS) and element-specific atomic emission detection (AED) were utilized to analyze seasonal changes in volatile components of preen oil secretions in Junco hyemalis. Juncos were held in long days to simulate breeding conditions, or short days to simulate nonbreeding conditions. Linear alcohols (C(10)-C(18)) were the major volatile compounds found in preen oil, and in both sexes their levels were higher when birds were housed on long as opposed to short days. Methylketones were found at lower levels, but were enhanced in both sexes during long days. Levels of 2-tridecanone, 2-tetradecanone, and 2-pentadecanone were also greater on long days, but only in males. Among carboxylic acids (C(12), C(14), and C(16)), linear but not branched acids showed some differences between the breeding and nonbreeding conditions, although the individual variation for acidic compounds was large. Qualitatively, more sulfur-containing compounds were found in males than females during the breeding season. Functionally, the large increase in linear alcohols in male and female preen oil during the breeding season may be an indication of altered lipid biosynthesis, which might signal reproductive readiness. Linear alcohols might also facilitate junco odor blending with plant volatiles in the habitat to distract mammalian predators. Some of the volatile compounds from preen oil, including linear alcohols, were also found on the wing feather surface, along with additional compounds that could have been of either metabolic or environmental origin.

  4. Whey-grape juice drink processed by supercritical carbon dioxide technology: Physicochemical characteristics, bioactive compounds and volatile profile.

    PubMed

    Amaral, Gabriela V; Silva, Eric Keven; Cavalcanti, Rodrigo N; Martins, Carolina P C; Andrade, Luiz Guilherme Z S; Moraes, Jeremias; Alvarenga, Verônica O; Guimarães, Jonas T; Esmerino, Erick A; Freitas, Mônica Q; Silva, Márcia C; Raices, Renata S L; Sant' Ana, Anderson S; Meireles, M Angela A; Cruz, Adriano G

    2018-01-15

    The effect of supercritical carbon dioxide technology (SCCD, 14, 16, and 18MPa at 35±2°C for 10min) on whey-grape juice drink characteristics was investigated. Physicochemical characterization (pH, titratable acidity, total soluble solids), bioactive compounds (phenolic compounds, anthocyanin, DPPH and ACE activity) and the volatile compounds were performed. Absence of differences were found among treatments for pH, titratable acidity, soluble solids, total anthocyanin and DPPH activity (p-value>0.05). A direct relationship between SCCD pressure and ACE inhibitory activity was observed, with 34.63, 38.75, and 44.31% (14, 16, and 18MPa, respectively). Regards the volatile compounds, it was noted few differences except by the presence of ketones. The findings confirm the SCCD processing as a potential promising technology to the conventional thermal treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Volatile compounds profile of sous-vide cooked pork cheeks as affected by cooking conditions (vacuum packaging, temperature and time).

    PubMed

    del Pulgar, Jose Sanchez; Roldan, Mar; Ruiz-Carrascal, Jorge

    2013-10-10

    The volatile organic compound (VOC) profile of pork cheeks as affected by the cooking conditions was investigated. Pork cheeks were cooked under different combinations of temperature (60 °C or 80 °C), time (5 or 12 h) and vacuum (vacuum or air-packaged). As a general rule, the VOCs originating from lipid degradation were positively affected by the cooking temperature and negatively by the cooking time, reaching the highest amounts in pork cheeks cooked at 80 °C during 5 h and the lowest in samples cooked at 80 °C during 12 h. On the contrary, VOCs originated from amino acids and Maillard reactions were positively affected by both factors. The proportion between lipid degradation and amino acids reactions was estimated by the hexanal/3-methylbutanal ratio, which reached its highest values in samples cooked at 60 °C during 5 h in the presence of air and the lowest values in samples cooked at 80 °C during 12 h, regardless of the vacuum status.

  6. Evaluating Oil and Gas Speciation Profiles with Factor Analysis of Ambient Volatile Organic Compound Concentrations in the Colorado Front Range

    NASA Astrophysics Data System (ADS)

    Capps, S.; Paranjothi, G.; Pierce, G. E.; Milford, J. B.

    2016-12-01

    Increased oil and gas (O&G) development, particularly through the use of hydraulic fracturing, in the Denver-Julesburg Basin (DJB) in Colorado over the last decade has been identified as a source of emissions of air pollutants, which are now included in chemical transport modeling. As one effort to evaluate its impact, ambient concentrations of volatile organic compounds (VOCs) that serve as precursors to ozone formation were measured in an Ozone Precursor Study conducted by the Colorado Department of Public Health and Environment during 2013 and 2014. The study included 6 - 9 a.m. measurements of an extensive suite of ozone-precursor VOCs from a site in an area of intensive O&G development in Platteville, CO, and another site in downtown Denver, CO. To evaluate the influences of urban activity or O&G development on these ambient concentrations, we used the U.S. EPA's Positive Matrix Factorization (PMF) tool. A five-factor PMF solution was selected as providing the best fit to the dataset comprised of VOC measurements for both years and both sites. One PMF factor matches the VOC emissions speciation profile for the flashing gas composition for condensate tanks in the DJB that was developed by the Western Regional Air Partnership for use in chemical transport modeling in the region. The contribution of this factor to individual and total VOC concentrations and ozone production reactivity is evaluated for Platteville and Denver.

  7. Profile of volatile compounds during papaya juice fermentation by a mixed culture of Saccharomyces cerevisiae and Williopsis saturnus.

    PubMed

    Lee, P-R; Ong, Y-L; Yu, B; Curran, P; Liu, S-Q

    2010-10-01

    This study investigated the formation and utilization of volatile compounds during papaya juice fermentation by a mixed culture of Saccharomyces cerevisiae and Williopsis saturnus. Time-course papaya juice fermentations were carried out using pure cultures of S. cerevisiae var. bayanus R2 and W. saturnus var. mrakii NCYC2251 and a mixed culture of the two yeasts at a ratio of 1:1000 (R2:NCYC2251). Changes in S. cerevisiae cell population, Brix, sugar consumption and pH were similar in the mixed culture and in the S. cerevisiae monoculture. There was an early growth arrest of W. saturnus in the mixed culture fermentation. A range of volatile compounds were produced during fermentation including fatty acids, alcohols, aldehydes and esters and some volatile compounds including those initially present in the juice were utilized. The mixed culture fermentation of S. cerevisiae and W. saturnus benefited from the presence of both yeasts, with more esters being produced than the S. cerevisiae monoculture and more alcohols being formed than the W. saturnus monoculture. The study suggests that papaya juice fermentation with a mixed culture of S. cerevisiae and W. saturnus may be able to result in the formation of more complex aroma compounds and higher ethanol level than those using single yeasts. 2010 Elsevier Ltd. All rights reserved.

  8. Differential profiling of volatile organic compound biomarker signatures utilizing a logical statistical filter-set and novel hybrid evolutionary classifiers

    NASA Astrophysics Data System (ADS)

    Grigsby, Claude C.; Zmuda, Michael A.; Boone, Derek W.; Highlander, Tyler C.; Kramer, Ryan M.; Rizki, Mateen M.

    2012-06-01

    A growing body of discoveries in molecular signatures has revealed that volatile organic compounds (VOCs), the small molecules associated with an individual's odor and breath, can be monitored to reveal the identity and presence of a unique individual, as well their overall physiological status. Given the analysis requirements for differential VOC profiling via gas chromatography/mass spectrometry, our group has developed a novel informatics platform, Metabolite Differentiation and Discovery Lab (MeDDL). In its current version, MeDDL is a comprehensive tool for time-series spectral registration and alignment, visualization, comparative analysis, and machine learning to facilitate the efficient analysis of multiple, large-scale biomarker discovery studies. The MeDDL toolset can therefore identify a large differential subset of registered peaks, where their corresponding intensities can be used as features for classification. This initial screening of peaks yields results sets that are typically too large for incorporation into a portable, electronic nose based system in addition to including VOCs that are not amenable to classification; consequently, it is also important to identify an optimal subset of these peaks to increase classification accuracy and to decrease the cost of the final system. MeDDL's learning tools include a classifier similar to a K-nearest neighbor classifier used in conjunction with a genetic algorithm (GA) that simultaneously optimizes the classifier and subset of features. The GA uses ROC curves to produce classifiers having maximal area under their ROC curve. Experimental results on over a dozen recognition problems show many examples of classifiers and feature sets that produce perfect ROC curves.

  9. The evolution of volatile compounds profile of "Toscano" dry-cured ham during ripening as revealed by SPME-GC-MS approach.

    PubMed

    Pugliese, C; Sirtori, F; Calamai, L; Franci, O

    2010-09-01

    The volatile compounds profile is an important feature for the characterization of dry-cured hams. Some minor typical Italian products, such as 'Toscano' ham, have been poorly studied in regards to their composition of volatile compounds. In this article, we studied the evolution of the aromatic profile of 'Toscano' dry-cured ham by solid-phase microextraction-gas chromatographic-mass spectrometry (SPME-GC-MS) with ripening. Ten right thighs were cured according to the 'Toscano' PDO protocol, sampled at 0, 1, 3, 6 and 12 months and submitted to volatile compounds analysis by SPME with a Divinylbenzene (DVB)/Carboxen/Polydimethylsiloxane (PDMS) 75-µ Stable Flex fibre. An Agilent 5975C mass selective detector (MSD) spectrometer with electron ionization (EI) source operating in scan mode within the m/z 29-350 range was used for data collection. Seven internal standards, either deuterium labeled or absent in the specimens and chosen to represent low or high boiling esters, alcohols, acids or phenols, were added to the homogenized samples and used to normalize the SPME fibre response to account for response changes upon wearing. Linear calibrations were obtained in this way for selected representative compounds. Over 60 compounds belonging to esters, aldehydes, organic acids, ketones and alcohols were identified by comparison with spectral libraries and Kovats indices. Aldehydes were the most represented chemical family, followed by organic acids, alcohols, ketones and esters. The aldehydes and ketones increased during the first 3 months, when the larger formation of volatiles occurred. For other families, the evolution over time was less evident. The principal component and discriminant analyses of the aromatic profile were effective in classifying the hams at 0, 6 or 12 months of ripening while for 1 and 3 months' samples a partial overlapping was shown. These results represent the first characterization of 'Toscano' ham and may constitute the basis to identify the

  10. Characterization and source profiling of volatile organic compounds in indoor air of private residences in Selangor State, Malaysia.

    PubMed

    Sakai, Nobumitsu; Yamamoto, Shuta; Matsui, Yasuto; Khan, Md Firoz; Latif, Mohd Talib; Ali Mohd, Mustafa; Yoneda, Minoru

    2017-05-15

    Volatile Organic Compounds (VOCs) in indoor air were investigated at 39 private residences in Selangor State, Malaysia to characterize the indoor air quality and to identify pollution sources. Twenty-two VOCs including isomers (14 aldehydes, 5 aromatic hydrocarbons, acetone, trichloroethylene and tetrachloroethylene) were collected by 2 passive samplers for 24h and quantitated using high performance liquid chromatography and gas chromatography mass spectrometry. Source profiling based on benzene/toluene ratio as well as statistical analysis (cluster analysis, bivariate correlation analysis and principal component analysis) was performed to identify pollution sources of the detected VOCs. The VOCs concentrations were compared with regulatory limits of air quality guidelines in WHO/EU, the US, Canada and Japan to clarify the potential health risks to the residents. The 39 residences were classified into 2 groups and 2 ungrouped residences based on the dendrogram in the cluster analysis. Group 1 (n=30) had mainly toluene (6.87±2.19μg/m(3)), formaldehyde (16.0±10.1μg/m(3)), acetaldehyde (5.35±4.57μg/m(3)) and acetone (11.1±5.95μg/m(3)) at background levels. Group 2 (n=7) had significantly high values of formaldehyde (99.3±10.7μg/m(3)) and acetone (35.8±12.6μg/m(3)), and a tendency to have higher values of acetaldehyde (23.7±13.5μg/m(3)), butyraldehyde (3.35±0.41μg/m(3)) and isovaleraldehyde (2.30±0.39μg/m(3)). The 2 ungrouped residences showed particularly high concentrations of BTX (benzene, toluene and xylene: 235μg/m(3) in total) or acetone (133μg/m(3)). The geometric mean value of formaldehyde (19.2μg/m(3)) exceeded an 8-hour regulatory limit in Canada (9μg/m(3)), while those in other compounds did not exceed any regulatory limits, although a few residences exceeded at least one regulatory limit of benzene or acetaldehyde. Thus, the VOCs in the private residences were effectively characterized from the limited number of monitoring, and the

  11. Characterization of plant-derived lactococci on the basis of their volatile compounds profile when grown in milk.

    PubMed

    Alemayehu, Debebe; Hannon, John A; McAuliffe, Olivia; Ross, R Paul

    2014-02-17

    A total of twelve strains of lactococci were isolated from grass and vegetables (baby corn and fresh green peas). Ten of the isolates were classified as Lactococcus lactis subsp. lactis and two as Lactococcus lactis subsp. cremoris based on 16S rDNA sequencing. Most of the plant-derived strains were capable of metabolising a wide range of carbohydrates in that they fermented D-mannitol, amygdalin, potassium gluconate, l-arabinose, d-xylose, sucrose and gentibiose. None of the dairy control strains (i.e. L. lactis subsp. cremoris HP, L. lactis subsp. lactis IL1403 and Lactococcus lactis 303) were able to utilize any of these carbohydrates. The technological potential of the isolates as flavour-producing lactococci was evaluated by analysing their growth in milk and their ability to produce volatile compounds using solid phase micro-extraction of the headspace coupled to gas chromatography-mass spectrometry (SPME GC-MS). Principal component analysis (PCA) of the volatile compounds clearly separated the dairy strains from the plant derived strains, with higher levels of most flavour rich compounds. The flavour compounds produced by the plant isolates among others included; fatty acids such as 2- and 3-methylbutanoic acids, and hexanoic acid, several esters (e.g. butyl acetate and ethyl butanoate) and ketones (e.g. acetoin, diacetyl and 2-heptanone), all of which have been associated with desirable and more mature flavours in cheese. As such the production of a larger number of volatile compounds is a distinguishing feature of plant-derived lactococci and might be a desirable trait for the production of dairy products with enhanced flavour and/or aroma.

  12. A profile of volatile organic compounds in exhaled air as a potential non-invasive biomarker for liver cirrhosis.

    PubMed

    Pijls, Kirsten E; Smolinska, Agnieszka; Jonkers, Daisy M A E; Dallinga, Jan W; Masclee, Ad A M; Koek, Ger H; van Schooten, Frederik-Jan

    2016-01-29

    Early diagnosis of liver cirrhosis may prevent progression and development of complications. Liver biopsy is the current standard, but is invasive and associated with morbidity. We aimed to identify exhaled volatiles within a heterogeneous group of chronic liver disease (CLD) patients that discriminates those with compensated cirrhosis (CIR) from those without cirrhosis, and compare this with serological markers. Breath samples were collected from 87 CLD and 34 CIR patients. Volatiles in exhaled air were measured by gas chromatography mass spectrometry. Discriminant Analysis was performed to identify the optimal panel of serological markers and VOCs for classifying our patients using a random training set of 27 CIR and 27 CLD patients. Two randomly selected independent internal validation sets and permutation test were used to validate the model. 5 serological markers were found to distinguish CIR and CLD patients with a sensitivity of 0.71 and specificity of 0.84. A set of 11 volatiles discriminated CIR from CLD patients with sensitivity of 0.83 and specificity of 0.87. Combining both did not further improve accuracy. A specific exhaled volatile profile can predict the presence of compensated cirrhosis among CLD patients with a higher accuracy than serological markers and can aid in reducing liver biopsies.

  13. A profile of volatile organic compounds in exhaled air as a potential non-invasive biomarker for liver cirrhosis

    PubMed Central

    Pijls, Kirsten E.; Smolinska, Agnieszka; Jonkers, Daisy M. A. E.; Dallinga, Jan W.; Masclee, Ad A. M.; Koek, Ger H.; van Schooten, Frederik-Jan

    2016-01-01

    Early diagnosis of liver cirrhosis may prevent progression and development of complications. Liver biopsy is the current standard, but is invasive and associated with morbidity. We aimed to identify exhaled volatiles within a heterogeneous group of chronic liver disease (CLD) patients that discriminates those with compensated cirrhosis (CIR) from those without cirrhosis, and compare this with serological markers. Breath samples were collected from 87 CLD and 34 CIR patients. Volatiles in exhaled air were measured by gas chromatography mass spectrometry. Discriminant Analysis was performed to identify the optimal panel of serological markers and VOCs for classifying our patients using a random training set of 27 CIR and 27 CLD patients. Two randomly selected independent internal validation sets and permutation test were used to validate the model. 5 serological markers were found to distinguish CIR and CLD patients with a sensitivity of 0.71 and specificity of 0.84. A set of 11 volatiles discriminated CIR from CLD patients with sensitivity of 0.83 and specificity of 0.87. Combining both did not further improve accuracy. A specific exhaled volatile profile can predict the presence of compensated cirrhosis among CLD patients with a higher accuracy than serological markers and can aid in reducing liver biopsies. PMID:26822454

  14. Variation of volatile compounds among wheat varieties and landraces.

    PubMed

    Starr, G; Petersen, M A; Jespersen, B M; Hansen, Å S

    2015-05-01

    Analysis of volatile compounds was performed on 81 wheat varieties and landraces, grown under controlled greenhouse conditions, in order to investigate the possibility of differentiating wheat varieties according to their volatile compound profiles. Volatile compounds from wheat samples were extracted by dynamic headspace extraction and analysed by gas chromatography-mass spectrometry. Seventy-two volatile compounds were identified in the wheat samples. Multivariate analysis of the data showed a large diversity in volatile profiles between samples. Differences occurred between samples from Austria compared to British, French and Danish varieties. Landraces were distinguishable from modern varieties and they were characterised by higher averaged peak areas for esters, alcohols, and some furans. Modern varieties were characterised by higher averaged peak areas for terpenes, pyrazines and straight-chained aldehydes. Differences in volatile profiles are demonstrated between wheat samples for the first time, based on variety. These results are significant to plant breeders and commercial users of wheat.

  15. Effect of e-beam irradiation and microwave heating on the fatty acid composition and volatile compound profile of grass carp surimi

    NASA Astrophysics Data System (ADS)

    Zhang, Hongfei; Wang, Wei; Wang, Haiyan; Ye, Qingfu

    2017-01-01

    In this study, we evaluated the effects of e-beam irradiation(1-7 kGy) and irradiation coupled to microwave heating (e-I-MC, 70 °C internal temperature) on the fatty acid composition and volatile compound profile of grass carp surimi. Compared to control samples, e-beam irradiation generated three novel volatile compounds (heptane, 2,6-dimethyl-nonane, and dimethyl disulfide) and increased the relative proportions of alcohols, aldehydes, and ketones. Meanwhile, e-I-MC significantly increased aldehyde levels and generated five heterocyclic compounds along with these three novel compounds. No significant difference in volatile compounds were detected in e-I-MC samples with increasing irradiation dose (p>0.05), comparing to the control group. E-beam irradiation at 5 and 7 kGy increased the levels of saturated fatty acids (SFAs) and decreased the levels of unsaturated fatty acids (p≤0.05), but did not affect the content of trans fatty acid levels (p>0.05). Irradiation, which had no significant effects on (Eicosapentaenoic acid) EPA, decreased (Docose Hexaenoie Acid) DHA levels. In the e-I-MC group, SFA levels increased and PUFA levels decreased. Additionally, MUFA levels were unaffected and trans fatty acid levels increased slightly following e-I-MC.

  16. Metabolite profiling of the ripening of Mangoes Mangifera indica L. cv. 'Tommy Atkins' by real-time measurement of volatile organic compounds.

    PubMed

    White, Iain R; Blake, Robert S; Taylor, Andrew J; Monks, Paul S

    Real-time profiling of mango ripening based on proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) of small molecular weight volatile organic compounds (VOCs), is demonstrated using headspace measurements of 'Tommy Atkins' mangoes. VOC metabolites produced during the ripening process were sampled directly, which enabled simultaneous and rapid detection of a wide range of compounds. Headspace measurements of 'Keitt' mangoes were also conducted for comparison. A principle component analysis of the results indicated that several mass channels were not only key to the ripening process but could also be used to distinguish between mango cultivars. The identities of 22 of these channels, tentatively speciated using contemporaneous GC-MS measurements of sorbent tubes, are rationalized through examination of the biochemical pathways that produce volatile flavour components. Results are discussed with relevance to the potential of headspace analysers and electronic noses in future fruit ripening and quality studies.

  17. Changes in volatile compounds and overall aroma profile during storage of coffee brews at 4 and 25 degrees C.

    PubMed

    Pérez-Martínez, Mónica; Sopelana, Patricia; de Peña, M Paz; Cid, Concepción

    2008-05-14

    In this work, the chemical changes occurring in the volatile fraction of Arabica coffee brews during storage at 4 and 25 degrees C for 30 days have been characterized for the first time by means of HS-GC-MS. A total of 47 compounds were identified and quantified: 2 sulfur compounds, 7 aldehydes, 3 esters, 15 furans, 5 ketones, 1 alcohol, 2 thiophenes, 4 pyrroles, 1 pyridine, 5 pyrazines, 1 alkene, and 1 acid. No new volatile compounds were detected at the end of the storage time. The changes observed are, in general, slower and less pronounced at refrigeration temperature. Storage also affects the sensory characteristics of the stored coffee brews, which lose part of their aroma intensity and freshness, acquiring some nondesirable notes such as rancid aroma, mainly during storage at 25 degrees C. Furthermore, seven aroma indices have been proposed as indicators of coffee brew staling, which show a good correlation with some sensory attributes, not only for aroma but also overall sensory quality. Consequently, they could be considered useful to monitor both the "age" and the sensory quality of stored coffee brews.

  18. Evaluation of different Saccharomyces cerevisiae strains on the profile of volatile compounds and polyphenols in cherry wines.

    PubMed

    Sun, Shu Yang; Jiang, Wen Guang; Zhao, Yu Ping

    2011-07-15

    Tart cherries of 'Early Richmond', widely grown in Shandong (China), were fermented with six different Saccharomyces cerevisiae strains (BM4×4, RA17, RC212, D254, D21 and GRE) to elucidate their influence on the production of volatiles and polyphenols. Acetic acid and 3-methylbutanol were found in the highest concentrations among all identified volatiles with all six yeast strains, followed by 2-methylpropanol and ethyl lactate. RA17 and GRE cherry wines were characterised by a higher amount of esters and acids. D254 wine contained a higher concentration of alcohols. With respect to polyphenols, five phenolic acids and four anthocyanins were identified among all tested samples, with chlorogenic and neochlorogenic acids, cyanidin 3-glucosylrutinoside and cyanidin 3-rutinoside being the major compounds. When using principal component analysis to classify the cherry wines according to the volatiles and polyphenols, they were divided into three groups: (1) RA17 and GRE, (2) RC212 and D254 and (3) BM4×4 and D21.

  19. Profile of volatile compounds in 11 brandies by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry.

    PubMed

    Zhao, Y; Xu, Y; Li, J; Fan, W; Jiang, W

    2009-03-01

    A headspace solid-phase microextraction (HS-SPME) method coupled with gas chromatography-mass spectrometry (GC-MS) was applied for the qualitative or semiquantitative characterization of brandy volatiles. SPME variables (SPME fiber, extraction temperature and time, and ethanol concentration) were optimized. A total of 144 compounds were from the brandies' volatiles, tentatively identified or identified by comparing mass spectra and retention indices of the standards or from literature. Of these, 57 are common to 11 brandies. They were mainly represented by esters and alcohols, such as 2-methyl propanol, 3-methyl butanol, 1-hexanol, ethyl octanoate, and ethyl decanoate, which were quantitatively determined. Chromatographic peaks were integrated using selective ion method (SIM) and the semiquantitative data analyzed using principal component analysis (PCA) and cluster analysis (CA) to study relationships between volatile composition and brandy. Eleven brandies were differentiated into 3 groups: 1 for Hennessy VSOP and XO samples, 1 for Changyu PEGASE VSOP and XO-1, 2, 3 samples, and the other for Changyu PEGASE brandy and VO, Taro brandy, Baiyang River brandy, and Wealth XO samples. The classification of groups is consistent with the brandy samples by variety and grade.

  20. Effectiveness of different solid-phase microextraction fibres for differentiation of selected Madeira island fruits based on their volatile metabolite profile--identification of novel compounds.

    PubMed

    Pereira, João; Pereira, Jorge; Câmara, José S

    2011-01-15

    A headspace solid-phase microextraction (HS-SPME) procedure based on five commercialised fibres (85 μm polyacrylate - PA, 100 μm polydimethylsiloxane - PDMS, 65 μm polydimethylsiloxane/divinylbenzene - PDMS/DVB, 70 μm carbowax/divinylbenzene - CW/DVB and 85 μm carboxen/polydimethylsiloxane - CAR/PDMS) is presented for the characterization of the volatile metabolite profile of four selected Madeira island fruit species, lemon (Citrus limon), kiwi (Actinidia deliciosa), papaya (Carica papaya L.) and Chickasaw plum (Prunus angustifolia). The isolation of metabolites was followed by thermal desorption gas chromatography-quadrupole mass spectrometry (GC-qMS) methodology. The performance of the target fibres was evaluated and compared. The SPME fibre coated with CW/DVB afforded the highest extraction efficiency in kiwi and papaya pulps, while in lemon and plum the same was achieved with PMDS/DVB fibre. This procedure allowed for the identification of 80 compounds, 41 in kiwi, 24 in plums, 23 in papaya and 20 in lemon. Considering the best extraction conditions, the most abundant volatiles identified in kiwi were the intense aldehydes and ethyl esters such as (E)-2-hexenal and ethyl butyrate, while in Chicasaw plum predominate 2-hexenal, 2-methyl-4-pentenal, hexanal, (Z)-3-hexenol and cyclohexylene oxide. The major compounds identified in the papaya pulp were benzyl isothiocyanate, linalool oxide, furfural, hydroxypropanone, linalool and acetic acid. Finally, lemon was shown to be the most divergent of the four fruits, being its aroma profile composed almost exclusively by terpens, namely limonene, γ-terpinene, o-cymene and α-terpinolene. Thirty two volatiles were identified for the first time in the fruit or close related species analysed and 14 volatiles are reported as novel volatile metabolites in fruits. This includes 5 new compounds in kiwi (2-cyclohexene-1,4-dione, furyl hydroxymethyl ketone, 4-hydroxydihydro-2(3H)-furanone, 5-acetoxymethyl-2-furaldehyde and

  1. The effect of antibrowning agents on inhibition of potato browning, volatile organic compound profile, and microbial inhibition.

    PubMed

    Mosneaguta, Ruslan; Alvarez, Valente; Barringer, Sheryl A

    2012-11-01

    Burbank and Norkotah potato slices were dipped into 3% sodium acid sulfate (SAS), citric acid (CA), sodium erythorbate (SE), malic acid (MA), sodium acid pyrophosphate (SAPP), or a combination of SAS-CA-SE. Browning by polyphenol oxidase (PPO) obtained from potato extract with 0.04 to 0.016 g/mL of antibrowning solutions at pH 2.0 to 6.9 were measured by UV-Vis spectroscopy. The color of slices dipped in antibrowning solutions at pHs 2 to 7 and stored at 4 °C for 15 d was measured every 5 d by colorimeter. Headspace analysis of volatiles in raw and cooked potato samples was performed by selected ion flow tube mass spectrometer (SIFT-MS) and soft independent modelling by class analogy (SIMCA) analysis of the calculated odor activity values (OAV) determined interclass distances. Microbial growth was measured at 15 d. At unadjusted pHs (1.1 to 7.1), the PPO browning of the control and samples with SAPP was not significantly different, SAS, CA, and MA produced some inhibition and SE and SAS-CA-SE prevented browning. At pH 5 to 7, only SE and SAS-CA-SE were effective browning inhibitors. Based on the color of potato slices, SE was the most effective at pH 2 to 7, but SAS was most effective at unadjusted pH. Cooking increased volatile levels in the treated potatoes and decreased differences between volatile profiles. Differences between cooked samples may not be noticeable by the consumer because volatiles with high discriminating powers have low OAVs. SAS, CA, and SAS-CA-SE treatments inhibited microbial growth but SAPP, control, and SE did not, most likely due to pH. Antibrowning agents inhibit polyphenol oxidase, increasing shelf life and consumer acceptability of processed raw potato products by preserving the color. Their effectiveness was shown to be mainly due to a pH effect, except SE, which was not pH dependent. MA, CA, and SAS-CA-SE are better acidulants for inhibition of color change as well as growth of spoilage bacteria, yeast, and mold than SAPP, the

  2. Volatile compounds from Melicope obscura.

    PubMed

    Smadja, Jacqueline; Strasberg, Dominique; Legoff, Géraldine; Gauvin-Bialecki, Anne

    2010-02-01

    To evaluate the interpopulation variability of volatile compounds in Melicope obscura, four samples representing four populations were collected all over the distribution area of the species in Reunion Island (Indian Ocean). The samples were extracted by hydrodistillation, and analyzed using GC/FID and GC/MS techniques. The study revealed that, in the four essential oils obtained, oxygenated sesquiterpenes were one of the major chemical classes (9.2-35.2%), mainly consisting of a new compound, (+)-6-ethenyl-2-hydroxy-6,10-dimethylundeca-2,9-dien-4-one (1), called melicopenol (8.6-30.1%). The compound was isolated by column chromatography and identified by spectral analyses including 1D- and 2D-NMR.

  3. Industrial sector-based volatile organic compound (VOC) source profiles measured in manufacturing facilities in the Pearl River Delta, China.

    PubMed

    Zheng, Junyu; Yu, Yufan; Mo, Ziwei; Zhang, Zhou; Wang, Xinming; Yin, Shasha; Peng, Kang; Yang, Yang; Feng, Xiaoqiong; Cai, Huihua

    2013-07-01

    Industrial sector-based VOC source profiles are reported for the Pearl River Delta (PRD) region, China, based source samples (stack emissions and fugitive emissions) analyzed from sources operating under normal conditions. The industrial sectors considered are printing (letterpress, offset and gravure printing processes), wood furniture coating, shoemaking, paint manufacturing and metal surface coating. More than 250 VOC species were detected following US EPA methods TO-14 and TO-15. The results indicated that benzene and toluene were the major species associated with letterpress printing, while ethyl acetate and isopropyl alcohol were the most abundant compounds of other two printing processes. Acetone and 2-butanone were the major species observed in the shoemaking sector. The source profile patterns were found to be similar for the paint manufacturing, wood furniture coating, and metal surface coating sectors, with aromatics being the most abundant group and oxygenated VOCs (OVOCs) as the second largest contributor in the profiles. While OVOCs were one of the most significant VOC groups detected in these five industrial sectors in the PRD region, they have not been reported in most other source profile studies. Such comparisons with other studies show that there are differences in source profiles for different regions or countries, indicating the importance of developing local source profiles. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  4. Volatile organic compound sensor system

    DOEpatents

    Schabron, John F [Laramie, WY; Rovani, Jr., Joseph F.; Bomstad, Theresa M [Waxahachie, TX; Sorini-Wong, Susan S [Laramie, WY; Wong, Gregory K [Laramie, WY

    2011-03-01

    Generally, this invention relates to the development of field monitoring methodology for new substances and sensing chemical warfare agents (CWAs) and terrorist substances. It also relates to a portable test kit which may be utilized to measure concentrations of halogenated volatile organic compounds (VOCs) in the field. Specifically it relates to systems for reliably field sensing the potential presence of such items while also distinguishing them from other elements potentially present. It also relates to overall systems and processes for sensing, reacting, and responding to an indicated presence of such substance, including modifications of existing halogenated sensors and arrayed sensing systems and methods.

  5. Volatile organic compound sensor system

    DOEpatents

    Schabron, John F [Laramie, WY; Rovani, Jr., Joseph F.; Bomstad, Theresa M [Laramie, WY; Sorini-Wong, Susan S [Laramie, WY

    2009-02-10

    Generally, this invention relates to the development of field monitoring methodology for new substances and sensing chemical warfare agents (CWAs) and terrorist substances. It also relates to a portable test kit which may be utilized to measure concentrations of halogenated volatile organic compounds (VOCs) in the field. Specifically it relates to systems for reliably field sensing the potential presence of such items while also distinguishing them from other elements potentially present. It also relates to overall systems and processes for sensing, reacting, and responding to an indicated presence of such substance, including modifications of existing halogenated sensors and arrayed sensing systems and methods.

  6. Effects of dairy system, herd within dairy system, and individual cow characteristics on the volatile organic compound profile of ripened model cheeses.

    PubMed

    Bergamaschi, M; Aprea, E; Betta, E; Biasioli, F; Cipolat-Gotet, C; Cecchinato, A; Bittante, G; Gasperi, F

    2015-04-01

    The objective of this work was to study the effect of dairy system, herd within dairy system, and characteristics of individual cows (parity, days in milk, and daily milk yield) on the volatile organic compound profile of model cheeses produced under controlled conditions from the milk of individual cows of the Brown Swiss breed. One hundred fifty model cheeses were selected from 1,272 produced for a wider study of the phenotypic and genetic variability of Brown Swiss cows. In our study, we selected 30 herds representing 5 different dairy systems. The cows sampled presented different milk yields (12.3-43.2kg/d), stages of lactation (10-412 d in milk), and parity (1-7). In total, 55 volatile compounds were detected by solid-phase microextraction and gas chromatography-mass spectrometry, including 14 alcohols, 13 esters, 11 free fatty acids, 8 ketones, 4 aldehydes, 3 lactones, 1 terpene, and 1 pyrazine. The most important sources of variation in the volatile organic profiles of model cheeses were dairy system (18 compounds) and days in milk (10 compounds), followed by parity (3 compounds) and milk yield (5 compounds). The model cheeses produced from the milk of tied cows reared on traditional farms had lower quantities of 3-methyl-butan-1-ol, 6-pentyloxan-2-one, 2-phenylethanol, and dihydrofuran-2(3H)-one compared with those reared in freestalls on modern farms. Of these, milk from farms using total mixed rations had higher contents of alcohols (hexan-1-ol, octan-1-ol) and esters (ethyl butanoate, ethyl pentanoate, ethyl hexanoate, and ethyl octanoate) and lower contents of acetic acid compared with those using separate feeds. Moreover, dairy systems that added silage to the total mixed ration produced cheeses with lower levels of volatile organic compounds, in particular alcohols (butan-1-ol, pentan-1-ol, heptan-1-ol), compared with those that did not. The amounts of butan-2-ol, butanoic acid, ethyl-2-methylpropanoate, ethyl-3-methylbutanoate, and 6-propyloxan-2-one

  7. Urinary metabolic profiling of volatile organic compounds in acute exposed volunteers after an oil spill in Republic of Korea.

    PubMed

    Lee, Jeongae; Kim, Min-hwa; Ha, Mina; Chung, Bong Chul

    2010-05-01

    The Herbei Spirit oil spill occurred in western Korea. A large number of people who participated in the cleanup tasks of the contaminated area were exposed to crude oil component. We developed a method to monitor volatile organic compound (VOC) metabolites in urine, and evaluate the acute exposure caused by the oil spill in exposed volunteer workers (n = 100, 20.7 +/- 2.1 years, mean +/- SD). Acidified urine samples were extracted by SPE, derivatized with trimethylsilyl, and analyzed using gas chromatography-mass spectrometry. Calibration curves were found to be linear from 3 to 1000 ng/mL (r(2) > 0.993). Accuracy was over 82.4%, and precision was less than 24.8%. Using this method, the VOC metabolites, except hippuric acid, were present at higher levels in the urine samples of volunteers after cleanup work. The levels of mandelic acid (MA) and trans,trans-muconic acid (t,t-MU) were increased significantly (p < 0.001). The exposure effect was greater in women than in men. The effect of smoking was analyzed in all exposed and non-exposed groups, with non-smokers showing increased MA and t,t-MU levels related to exposure. The present method was reliable to determine VOC metabolites in urine and could be useful for biomonitoring of acute exposure effects of VOCs. 2009 John Wiley & Sons, Ltd.

  8. Volatile organic compound sensing devices

    DOEpatents

    Lancaster, G.D.; Moore, G.A.; Stone, M.L.; Reagen, W.K.

    1995-08-29

    Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs. 15 figs.

  9. Volatile organic compound sensing devices

    DOEpatents

    Lancaster, Gregory D.; Moore, Glenn A.; Stone, Mark L.; Reagen, William K.

    1995-01-01

    Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs.

  10. Influence of oxygen and long term storage on the profile of volatile compounds released from polymeric multilayer food contact materials sterilized by gamma irradiation.

    PubMed

    Salafranca, Jesús; Clemente, Isabel; Isella, Francesca; Nerín, Cristina; Bosetti, Osvaldo

    2015-06-09

    The profile of volatile compounds released from 13 different multilayer polymeric materials for food use, before and after their exposure to gamma radiation, has been assessed by solid-phase microextraction-gas chromatography-mass spectrometry. Thermosealed bags of different materials were filled with either air or nitrogen to evaluate the oxygen influence. One-third of the samples were analyzed without irradiation, whereas the rest were irradiated at 15 and 25 kGy. Half of the samples were processed just after preparation and the other half was stored for 8 months at room temperature prior to analysis. Very significant differences between unirradiated and irradiated bags were found. About 60-80 compounds were released and identified per sample. A huge peak of 1,3-ditertbutylbenzene was present in most of the irradiated samples. An outstanding reproducibility in all the variables evaluated (chromatograms, oxygen percentage, volume of bags) was noticed. Independently of filling gas, the results of unirradiated materials were almost identical. In contrast, the chromatographic profile and the odor of irradiated bags filled with nitrogen were completely different to those filled with air. Principal component analysis was performed and 86.9% of the accumulated variance was explained with the first two components. The migration of compounds from irradiated materials to the vapor phase was much lower than the limits established in the Commission Regulation (EU) No 10/2011.

  11. Assessment of volatile compound profiles and the deduced sensory significance of virgin olive oils from the progeny of Picual×Arbequina cultivars.

    PubMed

    Pérez, Ana G; de la Rosa, Raúl; Pascual, Mar; Sánchez-Ortiz, Araceli; Romero-Segura, Carmen; León, Lorenzo; Sanz, Carlos

    2016-01-08

    Volatile compounds are responsible for most of the sensory qualities of virgin olive oil and they are synthesized when enzymes and substrates come together as olive fruit is crushed during the industrial process to obtain the oil. Here we have studied the variability among the major volatile compounds in virgin olive oil prepared from the progeny of a cross of Picual and Arbequina olive cultivars (Olea europaea L.). The volatile compounds were isolated by SPME, and analyzed by HRGC-MS and HRGC-FID. Most of the volatile compounds found in the progeny's oil are produced by the enzymes in the so-called lipoxygenase pathway, and they may be clustered into different groups according to their chain length and polyunsaturated fatty acid origin (linoleic and linolenic acids). In addition, a group of compounds derived from amino acid metabolism and two terpenes also contributed significantly to the volatile fraction, some of which had significant odor values in most of the genotypes evaluated. The volatile compound content of the progeny was very varied, widely transgressing the progenitor levels, suggesting that in breeding programs it might be more effective to consider a larger number of individuals within the same cross than using different crosses with fewer individuals. Multivariate analysis allowed genotypes with particularly interesting volatile compositions to be identified and their flavor quality deduced. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. 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.

  13. 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.

  14. Biodiversity of volatile organic compounds from five French ferns.

    PubMed

    Fons, Françoise; Froissard, Didier; Bessière, Jean-Marie; Buatois, Bruno; Rapior, Sylvie

    2010-10-01

    Five French ferns belonging to different families were investigated for volatile organic compounds (VOC) by GC-MS using organic solvent extraction. Fifty-five VOC biosynthesized from the shikimic, lipidic and terpenic pathways including monoterpenes, sesquiterpenes and carotenoid-type compounds were identified. The main volatile compound of Adiantum capillus-veneris L. (Pteridaceae) was (E)-2-decenal with a plastic or "stink bug" odor. The volatile profiles of Athyrium filix-femina (L.) Roth (Woodsiaceae) and Blechnum spicant (L.) Roth (Blechnaceae) showed similarities, with small amounts of isoprenoids and the same main volatile compounds, i.e., 2-phenylethanal (odor of lilac and hyacinth) and 1-octen-3-ol (mushroom-like odor). The main volatile compound of Dryopteris filix-mas (L.) Schott (Dryopteridaceae) was (E)-nerolidol with a woody or fresh bark note. Polyketides, as acylfilicinic acids, were mainly identified in this fern. Oreopteris limbosperma (Bellardi ex. All.) J. Holub (Thelypteridaceae), well-known for its lemon smell, contained the highest biodiversity of VOC. Eighty percent of the volatiles was issued from the terpenic pathway. The main volatiles were (E)-nerolidol, alpha-terpineol, beta-caryophyllene and other minor monoterpenes (for example, linalool, pinenes, limonene, and gamma-terpinen-7-al). It was also the fern with the highest number of carotenoid-type derivatives, which were identified in large amounts. Our results were of great interest underlying new industrial valorisation for ferns based on their broad spectrum of volatiles.

  15. Nitrogen compounds in must and volatile profile of white wine: Influence of clarification process before alcoholic fermentation.

    PubMed

    Burin, Vívian Maria; Caliari, Vinícius; Bordignon-Luiz, Marilde T

    2016-07-01

    The aim of this study was to investigate the effect of adding a fining agent to the must in relation to the fermentation kinetics and the volatile composition of the wine produced. Three fining agents, bentonite, pectinolytic enzyme and silica were applied, separately, to samples of Chardonnay must. It was observed that the addition of a fining agent had a significant influence on the must and wine composition. The must clarified with bentonite showed the lowest nitrogen content and the enzyme addition led to the highest nitrogen content. During the fermentation process, a difference in the consumption rate was observed for each amino acid in relation to the fining agent used in the process. In relation to the volatile composition, the wine produced had different characteristics according to the fining agent added to the must, which was confirmed by separation of the samples using principal component analysis. Copyright © 2016. Published by Elsevier Ltd.

  16. Analysis of volatile compounds from various types of barley cultivars.

    PubMed

    Cramer, Anne-Chrystelle J; Mattinson, D Scott; Fellman, John K; Baik, Byung-Kee

    2005-09-21

    We identified volatile compounds of barley flour and determined the variation in volatile compound profiles among different types and varieties of barley. Volatile compounds of 12 barley and two wheat cultivars were analyzed using solid phase microextraction (SPME) and gas chromatography. Twenty-six volatiles comprising aldehydes, ketones, alcohols, and a furan were identified in barley. 1-Octen-3-ol, 3-methylbutanal, 2-methylbutanal, hexanal, 2-hexenal, 2-heptenal, 2-nonenal, and decanal were identified as key odorants in barley as their concentration exceeded their odor detection threshold in water. Hexanal (46-1269 microg/L) and 1-pentanol (798-1811 microg/L) were the major volatile compounds in barley cultivars. In wheat, 1-pentanol (723-748 microg/L) was a major volatile. Hulled barley had higher total volatile, aldehyde, ketone, alcohol, and furan contents than hulless barley, highlighting the importance of the husk in barley grain aroma. The proanthocyanidin-free varieties generally showed higher total volatile and aldehyde contents than wild-type varieties, potentially due to decreased antioxidant activity by the absence of proanthocyanidins.

  17. Effect of autochthonous starter cultures isolated from Siahmazgi cheese on physicochemical, microbiological and volatile compound profiles and sensorial attributes of sucuk, a Turkish dry-fermented sausage.

    PubMed

    Kargozari, Mina; Moini, Sohrab; Akhondzadeh Basti, Afshin; Emam-Djomeh, Zahra; Gandomi, Hassan; Revilla Martin, Isabel; Ghasemlou, Mehran; Carbonell-Barrachina, Angel A

    2014-05-01

    The effect of adding autochthonous starter cultures isolated from Siahmazgi cheese, on the physicochemical parameters and microbial counts of sucuk was investigated during the ripening period. SPME-GC/MS was used in volatile compound analysis and a trained group of panelists carried out sensory analysis of the final product. After preliminary screening, three strains of Lactobacillus plantarum, which possess desirable technological properties, were used to prepare three starter cultures: LBP7, LBP10 and LBP14. The addition of LBP7 and LBP14 starter cultures had a significant effect (P<0.05) on lightness, leading to higher L values compared to control sausages during the ripening period. Both LBP7 and LBP14 sausages showed higher counts of lactic acid bacteria, lower growth of Enterobacteriaceae and Gram-positive catalase-positive cocci and greatly lowered the pH value compared to control sausages throughout the ripening process. At the end of the ripening process, lactic acid bacteria counts were affected (P<0.05) by the addition of starter culture since higher counts were observed in sausages prepared with LBP7 (9.14logCFU/g) and LBP14 (8.96logCFU/g) batches. The decrease of water activity during the ripening of sausages was not affected by the various starters. The texture profiles of all sausages were similar except for LBP10, which showed lower hardness and gumminess during ripening. Under the conditions of the study, volatile compounds were mainly from spices, and no marked differences were found among inoculated sausages. However, sensory evaluation revealed that most of the sensory attributes were scored higher for inoculated sausages than for the control ones. Therefore, LBP7 and LBP14 could be promising candidates for inclusion as starter cultures for the manufacture of sucuk.

  18. Extraction of oak volatiles and ellagitannins compounds and sensory profile of wine aged with French winewoods subjected to different toasting methods: behaviour during storage.

    PubMed

    Chira, Kleopatra; Teissedre, Pierre-Louis

    2013-09-01

    In Merlot wines the evolution of volatile and non-volatile (ellagitannins) compounds extracted from winewoods while being macerated for 12 months was studied. Seven types of winewoods subjected to different toasting methods were used. Different rates of extraction, depending mainly on wood compounds origin (toasting or naturally present in wood) and on the watering process during toasting, were observed, which were reflected in sensory differences. Globally, volatile phenols together with aldehydes, phenols and lactones showed an increase with increasing maceration time. Ellagitannins were extracted faster during the first 3 months; after 6 months an important decrease was observed. Wines with winewoods subjected to watering during toasting were lower in ellagitannins concentrations and demonstrated the greatest decrease of these compounds during maceration. Astringency and bitterness intensified with increasing ellagitannins. Lactones induced positive sweetness sensations, whereas furanic and guaiacol compounds influenced bitterness and astringency. Spicy and vanilla descriptors were related to eugenol, vanillin and other odorous chemicals.

  19. 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.

  20. Analyzing volatile compounds in dairy products

    USDA-ARS?s Scientific Manuscript database

    Volatile compounds give the first indication of the flavor in a dairy product. Volatiles are isolated from the sample matrix and then analyzed by chromatography, sensory methods, or an electronic nose. Isolation may be performed by solvent extraction or headspace analysis, and gas chromatography i...

  1. Effect of the dietary supplementation of essential oils from rosemary and artemisia on muscle fatty acids and volatile compound profiles in Barbarine lambs.

    PubMed

    Vasta, Valentina; Aouadi, Dorra; Brogna, Daniela M R; Scerra, Manuel; Luciano, Giuseppe; Priolo, Alessandro; Ben Salem, Hichem

    2013-10-01

    Eighteen Barbarine lambs (3 months of age), were assigned for 95 days to 3 treatments: six lambs were fed a barley-based concentrate plus oat hay ad libitum (control group, C); other lambs received the control diet plus essential oil (400 ppm DM) either of Rosmarinus officinalis (R400 group; n=6) or of Artemisia herba alba (A400 group; n=6). At slaughter the muscle longissimus dorsi was sampled and subjected to fatty acid and volatile organic compounds (VOC) analyses. The A400 lambs presented a greater amount of vaccenic, rumenic and linolenic acids and of polyunsaturated fatty acids (PUFA) in meat than the C and R400 animals. Essential oils supplementation did not affect meat VOC profile though the sesquiterpenes copaene and β-caryophyllene were detected only in the meat of R400 and A400 lambs. It is concluded that the supplementation of rosemary or artemisia essential oils does not produce detrimental effects on lamb meat VOC profile. The supplementation of artemisia can improve meat healthy properties.

  2. Mapping and profile of emission sources for airborne volatile organic compounds from process regions at a petrochemical plant in Kaohsiung, Taiwan.

    PubMed

    Chen, Ching-Liang; Fang, Hung-Yuan; Shu, Chi-Min

    2006-06-01

    This work surveyed five process regions inside a petrochemical plant in Taiwan to characterize the profiles of airborne volatile organic compounds (VOCs) and locate emission sources. Samples, taken with canisters, were analyzed with gas chromatography-mass spectrometry according to the TO-14 method. Each region was deployed with 24 sampling sites, sampled twice, and 240 samples in total were measured during the survey period. All of the data were consolidated into a database on Excel to facilitate retrieval, statistical analysis, and presentation in the form of a table or graph, and, subsequently, the profile of VOCs was elucidated. Emission sources were located by mapping the concentration distribution of either an individual or a type of species in terms of contour maps on Surfer. Through the cross-analysis of data, the abundant VOCs included alkenes, dienes, alkanes, and aromatics. A total of 19 emission sources were located from these five regions. The sources for alkanes stood inside first, third aromatic, and fourth naphtha cracking regions, whereas the ones for alkenes were inside two naphtha cracking regions. The sources for dienes were found inside the third naphtha cracking region alone; in contrast, the sources for aromatics were universally traced except inside the third naphtha cracking region. The measured intensity for sources mostly ranged from 1000 to 7000 ppb.

  3. Microwave spectra of some volatile organic compounds

    NASA Technical Reports Server (NTRS)

    White, W. F.

    1975-01-01

    A computer-controlled microwave (MRR) spectrometer was used to catalog reference spectra for chemical analysis. Tables of absorption frequency, peak absorption intensity, and integrated intensity are included for 26 volatile organic compounds, all but one of which contain oxygen.

  4. VOLATILE ORGANIC COMPOUNDS AS EXPOSURE BIOMARKERS

    EPA Science Inventory

    Alveolar breath sampling and analysis can be extremely useful in exposure assessment studies involving volatile organic compounds (VOCs). Over recent years scientists from the US Environmental Protection Agency's National Exposure Research Laboratory have developed and refined...

  5. VOLATILE ORGANIC COMPOUNDS AS EXPOSURE BIOMARKERS

    EPA Science Inventory

    Alveolar breath sampling and analysis can be extremely useful in exposure assessment studies involving volatile organic compounds (VOCs). Over recent years scientists from the US Environmental Protection Agency's National Exposure Research Laboratory have developed and refined...

  6. Biosynthesis, function and metabolic engineering of plant volatile organic compounds.

    PubMed

    Dudareva, Natalia; Klempien, Antje; Muhlemann, Joëlle K; Kaplan, Ian

    2013-04-01

    Plants synthesize an amazing diversity of volatile organic compounds (VOCs) that facilitate interactions with their environment, from attracting pollinators and seed dispersers to protecting themselves from pathogens, parasites and herbivores. Recent progress in -omics technologies resulted in the isolation of genes encoding enzymes responsible for the biosynthesis of many volatiles and contributed to our understanding of regulatory mechanisms involved in VOC formation. In this review, we largely focus on the biosynthesis and regulation of plant volatiles, the involvement of floral volatiles in plant reproduction as well as their contribution to plant biodiversity and applications in agriculture via crop-pollinator interactions. In addition, metabolic engineering approaches for both the improvement of plant defense and pollinator attraction are discussed in light of methodological constraints and ecological complications that limit the transition of crops with modified volatile profiles from research laboratories to real-world implementation.

  7. A novel Whole Air Sample Profiler (WASP) for the quantification of volatile organic compounds in the boundary layer

    SciTech Connect

    Mak, J. E.; Su, L.; Guenther, Alex B.; Karl, Thomas G.

    2013-10-16

    The emission and fate of reactive VOCs is of inherent interest to those studying chemical biosphere-atmosphere interactions. In-canopy VOC observations are obtainable using tower-based samplers, but the lack of suitable sampling systems for the full boundary 5 layer has limited the data characterizing the vertical structure of such gases above the canopy height and still in the boundary layer. This is the important region where many reactive VOCs are oxidized or otherwise removed. Here we describe an airborne sampling system designed to collect a vertical profile of air into a 3/800 OD tube 150m in length. The inlet ram air pressure is used to flow sampled air through the 10 tube, which results in a varying flow rate based on aircraft speed and altitude. Since aircraft velocity decreases during ascent, it is necessary to account for the variable flow rate into the tube. This is accomplished using a reference gas that is pulsed into the air stream so that the precise altitude of the collected air can be reconstructed post-collection. The pulsed injections are also used to determine any significant effect 15 from diffusion/mixing within the sampling tube, either during collection or subsequent extraction for gas analysis. This system has been successfully deployed, and we show some measured vertical profiles of isoprene and its oxidation products methacrolein and methyl vinyl ketone from a mixed canopy near Columbia, Missouri.

  8. VOLATILE ORGANIC COMPOUNDS (VOCS) CHAPTER 31.

    EPA Science Inventory

    The term "volatile organic compounds' (VOCs) was originally coined to refer, as a class, to carbon-containing chemicals that participate in photochemical reactions in the ambient (outdoor) are. The regulatory definition of VOCs used by the U.S. EPA is: Any compound of carbon, ex...

  9. VOLATILE ORGANIC COMPOUNDS (VOCS) CHAPTER 31.

    EPA Science Inventory

    The term "volatile organic compounds' (VOCs) was originally coined to refer, as a class, to carbon-containing chemicals that participate in photochemical reactions in the ambient (outdoor) are. The regulatory definition of VOCs used by the U.S. EPA is: Any compound of carbon, ex...

  10. Volatile organic compound emissions from silage systems

    USDA-ARS?s Scientific Manuscript database

    As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major source from farms is silage, with emissions coming from the silo face, mixing wagon, and feed bunk. The major compounds emitted are alcohols with other impor...

  11. Emission and profile characteristic of volatile organic compounds emitted from coke production, iron smelt, heating station and power plant in Liaoning Province, China.

    PubMed

    Shi, Jianwu; Deng, Hao; Bai, Zhipeng; Kong, Shaofei; Wang, Xiuyan; Hao, Jiming; Han, Xinyu; Ning, Ping

    2015-05-15

    107 kinds of C₂-C₁₂ volatile organic compound (VOC) mass concentrations and profiles for four types of coal-fired stationary sources in Liaoning Province were studied by a dilution sampling system and GC-MS analysis method, which are of significant importance with regard to VOC emissions in northeast of China. The results showed that there were some differences among these VOC source profiles. The total mass concentrations of analyzed 107 VOC species varied from 10,917 to 19,652 μg m(-3). Halogenated hydrocarbons exhibited higher mass percentages for the VOC source profiles of iron smelt (48.8%) and coke production plant (37.7%). Aromatic hydrocarbons were the most abundant in heating station plant (69.1%). Ketones, alcohols and acetates held 45.0% of total VOCs in thermal power plant. For non-methane hydrocarbons (NMHCs), which are demanded for photochemical assessment in the USA, toluene and n-hexane were the most abundant species in the iron smelt, coke production and thermal power plant, with the mass percentages of 64.8%, 52.7% and 38.6%, respectively. Trimethylbenzene, n-propylbenzene and o,m-ethyltoluene approximately accounted for 70.0% in heating station plant. NMHCs emitted from coke production, iron smelt, heating station and power plant listed above presented different chemical reactivities. The average OH loss rate of NMHCs from heating station, was 4 to 5.6 times higher than that of NMHCs from iron smelt, coke production and power plant, which implies that VOCs emitted from heating station in northeast of China should be controlled firstly to avoid photochemical ozone pollution and protect human health. There are significant variations in the ratios of benzene/toluene and m, p-xylene/ethylbenzene of these coal-fired source profiles. The representativeness of the coal-fired sources studied and the VOC samples collected should be more closely examined. The accuracy of VOC source profiles related to coal-fired processes is highly dependent on

  12. Multiple internal standard normalization for improving HS-SPME-GC-MS quantitation in virgin olive oil volatile organic compounds (VOO-VOCs) profile.

    PubMed

    Fortini, Martina; Migliorini, Marzia; Cherubini, Chiara; Cecchi, Lorenzo; Calamai, Luca

    2017-04-01

    The commercial value of virgin olive oils (VOOs) strongly depends on their classification, also based on the aroma of the oils, usually evaluated by a panel test. Nowadays, a reliable analytical method is still needed to evaluate the volatile organic compounds (VOCs) and support the standard panel test method. To date, the use of HS-SPME sampling coupled to GC-MS is generally accepted for the analysis of VOCs in VOOs. However, VOO is a challenging matrix due to the simultaneous presence of: i) compounds at ppm and ppb concentrations; ii) molecules belonging to different chemical classes and iii) analytes with a wide range of molecular mass. Therefore, HS-SPME-GC-MS quantitation based upon the use of external standard method or of only a single internal standard (ISTD) for data normalization in an internal standard method, may be troublesome. In this work a multiple internal standard normalization is proposed to overcome these problems and improving quantitation of VOO-VOCs. As many as 11 ISTDs were used for quantitation of 71 VOCs. For each of them the most suitable ISTD was selected and a good linearity in a wide range of calibration was obtained. Except for E-2-hexenal, without ISTD or with an unsuitable ISTD, the linear range of calibration was narrower with respect to that obtained by a suitable ISTD, confirming the usefulness of multiple internal standard normalization for the correct quantitation of VOCs profile in VOOs. The method was validated for 71 VOCs, and then applied to a series of lampante virgin olive oils and extra virgin olive oils. In light of our results, we propose the application of this analytical approach for routine quantitative analyses and to support sensorial analysis for the evaluation of positive and negative VOOs attributes.

  13. Analyzing volatile compounds in dairy products.

    PubMed

    Tunick, Michael H

    2014-07-01

    Volatile compounds give the first indication of the flavor in a dairy product. Volatiles are isolated from the sample matrix and then analyzed by chromatography, sensory methods or an electronic nose. Isolation may be performed by solvent extraction or headspace analysis, and gas chromatography is often employed with various detectors to identify odorants. The human nose is also used as a detector, and electronic noses are being developed to qualitate and quantitate volatiles. A reliable technique for analyzing odorants in dairy products has not yet been invented.

  14. Determination of Volatile Flavour Profiles of Citrus spp. Fruits by SDE-GC-MS and Enantiomeric Composition of Chiral Compounds by MDGC-MS.

    PubMed

    Hong, Joon Ho; Khan, Naeem; Jamila, Nargis; Hong, Young Shin; Nho, Eun Yeong; Choi, Ji Yeon; Lee, Cheong Mi; Kim, Kyong Su

    2017-09-01

    Citrus fruits are known to have characteristic enantiomeric key compounds biosynthesised by highly stereoselective enzymatic mechanisms. In the past, evaluation of the enantiomeric ratios of chiral compounds in fruits has been applied as an effective indicator of adulteration by the addition of synthetic compounds or natural components of different botanical origin. To analyse the volatile flavour compounds of Citrus junos Sieb. ex Tanaka (yuzu), Citrus limon BURM. f. (lemon) and Citrus aurantifolia Christm. Swingle (lime), and determine the enantiomeric ratios of their chiral compounds for discrimination and authentication of extracted oils. Volatile flavour compounds of the fruits of the three Citrus species were extracted by simultaneous distillation extraction and analysed by gas chromatography-mass spectrometry. The enantiomeric composition (ee%) of chiral camphene, sabinene, limonene and β-phellandrene was analysed by heart-cutting multidimensional gas chromatography-mass spectrometry. Sixty-seven (C. junos), 77 (C. limon) and 110 (C. aurantifolia) volatile compounds were identified with limonene, γ-terpinene and linalool as the major compounds. Stereochemical analysis (ee%) revealed 1S,4R-(-) camphene (94.74, 98.67, 98.82), R-(+)-limonene (90.53, 92.97, 99.85) and S-(+)-β-phellandrene (98.69, 97.15, 92.13) in oil samples from all three species; R-(+)-sabinene (88.08) in C. junos; and S-(-)-sabinene (81.99, 79.74) in C. limon and C. aurantifolia, respectively. The enantiomeric composition and excess ratios of the chiral compounds could be used as reliable indicators of genuineness and quality assurance of the oils derived from the Citrus fruit species. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  15. [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.

  16. Analyses of volatile organic compounds from human skin

    PubMed Central

    Gallagher, M.; Wysocki, C.J.; Leyden, J.J.; Spielman, A.I.; Sun, X.; Preti, G.

    2008-01-01

    Summary Background Human skin emits a variety of volatile metabolites, many of them odorous. Much previous work has focused upon chemical structure and biogenesis of metabolites produced in the axillae (underarms), which are a primary source of human body odour. Nonaxillary skin also harbours volatile metabolites, possibly with different biological origins than axillary odorants. Objectives To take inventory of the volatile organic compounds (VOCs) from the upper back and forearm skin, and assess their relative quantitative variation across 25 healthy subjects. Methods Two complementary sampling techniques were used to obtain comprehensive VOC profiles, viz., solid-phase micro extraction and solvent extraction. Analyses were performed using both gas chromatography/mass spectrometry and gas chromatography with flame photometric detection. Results Nearly 100 compounds were identified, some of which varied with age. The VOC profiles of the upper back and forearm within a subject were, for the most part, similar, although there were notable differences. Conclusions The natural variation in nonaxillary skin odorants described in this study provides a baseline of compounds we have identified from both endogenous and exogenous sources. Although complex, the profiles of volatile constituents suggest that the two body locations share a considerable number of compounds, but both quantitative and qualitative differences are present. In addition, quantitative changes due to ageing are also present. These data may provide future investigators of skin VOCs with a baseline against which any abnormalities can be viewed in searching for biomarkers of skin diseases. PMID:18637798

  17. The volatile compound BinBase mass spectral database

    PubMed Central

    2011-01-01

    Background Volatile compounds comprise diverse chemical groups with wide-ranging sources and functions. These compounds originate from major pathways of secondary metabolism in many organisms and play essential roles in chemical ecology in both plant and animal kingdoms. In past decades, sampling methods and instrumentation for the analysis of complex volatile mixtures have improved; however, design and implementation of database tools to process and store the complex datasets have lagged behind. Description The volatile compound BinBase (vocBinBase) is an automated peak annotation and database system developed for the analysis of GC-TOF-MS data derived from complex volatile mixtures. The vocBinBase DB is an extension of the previously reported metabolite BinBase software developed to track and identify derivatized metabolites. The BinBase algorithm uses deconvoluted spectra and peak metadata (retention index, unique ion, spectral similarity, peak signal-to-noise ratio, and peak purity) from the Leco ChromaTOF software, and annotates peaks using a multi-tiered filtering system with stringent thresholds. The vocBinBase algorithm assigns the identity of compounds existing in the database. Volatile compound assignments are supported by the Adams mass spectral-retention index library, which contains over 2,000 plant-derived volatile compounds. Novel molecules that are not found within vocBinBase are automatically added using strict mass spectral and experimental criteria. Users obtain fully annotated data sheets with quantitative information for all volatile compounds for studies that may consist of thousands of chromatograms. The vocBinBase database may also be queried across different studies, comprising currently 1,537 unique mass spectra generated from 1.7 million deconvoluted mass spectra of 3,435 samples (18 species). Mass spectra with retention indices and volatile profiles are available as free download under the CC-BY agreement (http

  18. Volatile compounds in shergottite and nakhlite meteorites

    NASA Technical Reports Server (NTRS)

    Gooding, James L.; Aggrey, Kwesi E.; Muenow, David W.

    1990-01-01

    Since discovery of apparent carbonate carbon in Nakhla, significant evidence has accumulated for occurrence of volatile compounds in shergotties and nakhlites. Results are presented from a study of volatile compounds in three shergottites, one nakhlite, and three eucrite control samples. Shergotties ALHA77005, EETA79001, and Shergotty, and the nakhlite Nakhla, all contain oxidized sulfur (sulfate) of preterrestrial origin; sulfur oxidation is most complete in EETA79001/Lith-C. Significant bulk carbonate was confirmed in Nakhla and trace carbonate was substantiated for EETA79001, all of which appears to be preterrestrial in origin. Chlorine covaries with oxidized sulfur, whereas carbonate and sulfate are inversely related. These volatile compounds were probably formed in a highly oxidizing, aqueous environment sometime in the late stage histories of the rocks that are now represented as meteorites. They are consistent with the hypothesis that shergottite and nakhlite meteorites originated on Mars and that Mars has supported aqueous geochemistry during its history.

  19. Analyzing method on biogenic volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Bai, J. H.; Wang, M. X.; Hu, F.; Greenberg, J. P.; Guenther, A. B.

    2002-02-01

    In order to analyze biogenic volatile organic compounds in the atmosphere, an automated gas chromatography is developed and employed at the laboratory of National Center for Atmospheric Research (NCAR) during January to July, 2000. A small refrigerator was used so as to remove water in the air sample from gas line, and get accurate concentrations of volatile organic compounds. At 5degreesC, good water removing efficiency can be obtained at controlled flow rate. Air samples were collected around the building of Mesa Lab. of NCAR and analyzed by this gas chromatography system. This paper reports this gas chromatography system and results of air samples. The experimental results show that this gas chromatography system has a good reproducibility and stability, and main interesting volatile organic compounds such as isoprene, monoterpenes have an evident diurnal variation.

  20. Catalyst for Oxidation of Volatile Organic Compounds

    NASA Technical Reports Server (NTRS)

    Wood, George M. (Inventor); Upchurch, Billy T. (Inventor); Schryer, David R. (Inventor); Davis, Patricia P. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); Schyryer, Jacqueline L. (Inventor); DAmbrosia, Christine M. (Inventor)

    2000-01-01

    Disclosed is a process for oxidizing volatile organic compounds to carbon dioxide and water with the minimal addition of energy. A mixture of the volatile organic compound and an oxidizing agent (e.g. ambient air containing the volatile organic compound) is exposed to a catalyst which includes a noble metal dispersed on a metal oxide which possesses more than one oxidation state. Especially good results are obtained when the noble metal is platinum, and the metal oxide which possesses more than one oxidation state is tin oxide. A promoter (i.e., a small amount of an oxide of a transition series metal) may be used in association with the tin oxide to provide very beneficial results.

  1. Volatile compound formation during argan kernel roasting.

    PubMed

    El Monfalouti, Hanae; Charrouf, Zoubida; Giordano, Manuela; Guillaume, Dominique; Kartah, Badreddine; Harhar, Hicham; Gharby, Saïd; Denhez, Clément; Zeppa, Giuseppe

    2013-01-01

    Virgin edible argan oil is prepared by cold-pressing argan kernels previously roasted at 110 degrees C for up to 25 minutes. The concentration of 40 volatile compounds in virgin edible argan oil was determined as a function of argan kernel roasting time. Most of the volatile compounds begin to be formed after 15 to 25 minutes of roasting. This suggests that a strictly controlled roasting time should allow the modulation of argan oil taste and thus satisfy different types of consumers. This could be of major importance considering the present booming use of edible argan oil.

  2. Differentiation of Commercial PDO Wines Produced in Istria (Croatia) According to Variety and Harvest Year Based on HS-SPME-GC/MS Volatile Aroma Compound Profiling.

    PubMed

    Lukić, Igor; Horvat, Ivana

    2017-03-01

    To differentiate monovarietal wines made from native and introduced varieties in Istria (Croatia), samples of Malvazija istarska, Chardonnay and Muscat yellow from two harvest years (2013 and 2014) were subjected to headspace solid-phase microextraction and gas chromatographic/mass spectrometric analysis (HS-SPME-GC/MS) of volatile aroma compounds. Significant effects of variety and harvest year were determined, but their interaction complicated the differentiation. Particular compounds were consistent as markers of variety in both years: nerol for Malvazija, ethyl cinnamate and a tentatively identified isomer of dimethylbenzaldehyde for Chardonnay, and terpenes for Muscat yellow. Wines from 2013 contained higher concentrations of the majority of important volatiles. A 100% correct differentiation of Malvazija istarska and Chardonnay wines according to both variety and harvest year was achieved by stepwise linear discriminant analysis.

  3. Differentiation of Commercial PDO Wines Produced in Istria (Croatia) According to Variety and Harvest Year Based on HS-SPME-GC/MS Volatile Aroma Compound Profiling

    PubMed Central

    Horvat, Ivana

    2017-01-01

    Summary To differentiate monovarietal wines made from native and introduced varieties in Istria (Croatia), samples of Malvazija istarska, Chardonnay and Muscat yellow from two harvest years (2013 and 2014) were subjected to headspace solid-phase microextraction and gas chromatographic/mass spectrometric analysis (HS-SPME-GC/MS) of volatile aroma compounds. Significant effects of variety and harvest year were determined, but their interaction complicated the differentiation. Particular compounds were consistent as markers of variety in both years: nerol for Malvazija, ethyl cinnamate and a tentatively identified isomer of dimethylbenzaldehyde for Chardonnay, and terpenes for Muscat yellow. Wines from 2013 contained higher concentrations of the majority of important volatiles. A 100% correct differentiation of Malvazija istarska and Chardonnay wines according to both variety and harvest year was achieved by stepwise linear discriminant analysis. PMID:28559738

  4. Composition and volatile profiles of commercial Argentinean blue cheeses.

    PubMed

    Wolf, Irma V; Perotti, María C; Zalazar, Carlos A

    2011-01-30

    A first approach was made to acquire knowledge of the global composition, proteolysis, lipolysis and volatile profile of Argentinean blue cheeses. A total of 20 samples belonging to six leading commercial brands were analysed. A comparison of the results with bibliographical data on other blue cheeses was performed and the variability among and within dairy plants was also evaluated. Values of global composition were intermediate in relation to those reported for mould-ripened cheeses. Levels of proteolysis and lipolysis were lower than those of other blue cheeses. Volatile compound profiles were characterised mainly by short-chain fatty acids, methyl ketones and secondary alcohols, as reported previously for blue cheeses. Wide-ranging values of physicochemical parameters, lipolysis and proteolysis levels as well as volatile compound areas of cheeses produced by each dairy plant were observed. Owing to this high variability in the chemistry and volatile profile of cheeses, principal component analysis of the data did not show groupings by commercial brands. On the whole, Argentinean blue cheeses were characterised both by gross intermediate composition values and by proteolysis and lipolysis levels lower than those of blue cheeses of different origins. A typical volatile compound profile of blue cheeses was observed. The high variability found within each commercial brand could reflect the lack of standardisation of the technological processes used in blue cheese manufacturing in Argentina. 2010 Society of Chemical Industry.

  5. Volatile Compound Profiling by HS-SPME/GC-MS-FID of a Core Olive Cultivar Collection as a Tool for Aroma Improvement of Virgin Olive Oil.

    PubMed

    García-Vico, Lourdes; Belaj, Angjelina; Sánchez-Ortiz, Araceli; Martínez-Rivas, José M; Pérez, Ana G; Sanz, Carlos

    2017-01-14

    Virgin olive oil (VOO) is the only food product requiring official sensory analysis to be classified in commercial categories, in which the evaluation of the aroma plays a very important role. The selection of parents, with the aim of obtaining new cultivars with improved oil aroma, is of paramount importance in olive breeding programs. We have assessed the volatile fraction by headspace-solid-phase microextraction/gas chromatography-mass spectrometry-flame ionization detection (HS-SPME/GC-MS-FID) and the deduced aroma properties of VOO from a core set of olive cultivars (Core-36) which possesses most of the genetic diversity found in the World Olive Germplasm Collection (IFAPA Alameda del Obispo) located in Cordoba, Spain. The VOO volatile fractions of Core-36 cultivars display a high level of variability. It is mostly made of compounds produced from polyunsaturated fatty acids through the lipoxygenase pathway, which confirms to be a general characteristic of the olive species (Olea europaea L.). The main group of volatile compounds in the oils was six straight-chain carbon compounds derived from linolenic acid, some of them being the main contributors to the aroma of the olive oils according to their odor activity values (OAV). The high level of variability found for the volatile fraction of the oils from Core-36 and, therefore, for the aroma odor notes, suggest that this core set may be a very useful tool for the choice of optimal parents in olive breeding programs in order to raise new cultivars with improved VOO aroma.

  6. Rapid and direct volatile compound profiling of black and green teas (Camellia sinensis) from different countries with PTR-ToF-MS.

    PubMed

    Yener, Sine; Sánchez-López, José A; Granitto, Pablo M; Cappellin, Luca; Märk, Tilmann D; Zimmermann, Ralf; Bonn, Günther K; Yeretzian, Chahan; Biasioli, Franco

    2016-05-15

    Volatile profiles of 63 black and 38 green teas from different countries were analysed with Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) both for tea leaves and tea infusion. The headspace volatile fingerprints were collected and the tea classes and geographical origins were tracked with pattern recognition techniques. The high mass resolution achieved by ToF mass analyser provided determination of sum formula and tentative identifications of the mass peaks. The results provided successful separation of the black and green teas based on their headspace volatile emissions both from the dry tea leaves and their infusions. The volatile fingerprints were then used to build different classification models for discrimination of black and green teas according to their geographical origins. Two different cross validation methods were applied and their effectiveness for origin discrimination was discussed. The classification models showed a separation of black and green teas according to geographical origins the errors being mostly between neighbouring countries. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Improved provincial emission inventory and speciation profiles of anthropogenic non-methane volatile organic compounds: a case study for Jiangsu, China

    NASA Astrophysics Data System (ADS)

    Zhao, Yu; Mao, Pan; Zhou, Yaduan; Yang, Yang; Zhang, Jie; Wang, Shekou; Dong, Yanping; Xie, Fangjian; Yu, Yiyong; Li, Wenqing

    2017-06-01

    Non-methane volatile organic compounds (NMVOCs) are the key precursors of ozone (O3) and secondary organic aerosol (SOA) formation. Accurate estimation of their emissions plays a crucial role in air quality simulation and policy making. We developed a high-resolution anthropogenic NMVOC emission inventory for Jiangsu in eastern China from 2005 to 2014, based on detailed information of individual local sources and field measurements of source profiles of the chemical industry. A total of 56 NMVOCs samples were collected in nine chemical plants and were then analyzed with a gas chromatography - mass spectrometry system (GC-MS). Source profiles of stack emissions from synthetic rubber, acetate fiber, polyether, vinyl acetate and ethylene production, and those of fugitive emissions from ethylene, butanol and octanol, propylene epoxide, polyethylene and glycol production were obtained. Various manufacturing technologies and raw materials led to discrepancies in source profiles between our domestic field tests and foreign results for synthetic rubber and ethylene production. The provincial NMVOC emissions were calculated to increase from 1774 Gg in 2005 to 2507 Gg in 2014, and relatively large emission densities were found in cities along the Yangtze River with developed economies and industries. The estimates were larger than those from most other available inventories, due mainly to the complete inclusion of emission sources and to the elevated activity levels from plant-by-plant investigation in this work. Industrial processes and solvent use were the largest contributing sectors, and their emissions were estimated to increase, respectively, from 461 to 958 and from 38 to 966 Gg. Alkanes, aromatics and oxygenated VOCs (OVOCs) were the most important species, accounting for 25.9-29.9, 20.8-23.2 and 18.2-21.0 % to annual total emissions, respectively. Quantified with a Monte Carlo simulation, the uncertainties of annual NMVOC emissions vary slightly through the years

  8. 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.

  9. Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

    PubMed

    Kim, Youngmok; Lee, Kwang-Geun; Kim, Mina K

    2016-10-01

    Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164 mg/L), in comparison to later harvested green teas (11,961 mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

  10. Volatile Organic Compound Emissions from Dairy Facilities in Central California

    NASA Astrophysics Data System (ADS)

    Hasson, A. S.; Ogunjemiyo, S. O.; Trabue, S.; Middala, S. R.; Ashkan, S.; Scoggin, K.; Vu, K. K.; Addala, L.; Olea, C.; Nana, L.; Scruggs, A. K.; Steele, J.; Shelton, T. C.; Osborne, B.; McHenry, J. R.

    2011-12-01

    Emissions of volatile organic compounds (VOCs) from dairy facilities are thought to be an important contributor to high ozone levels in Central California, but emissions inventories from these sources contain significant uncertainties. In this work, VOC emissions were measured at two Central California dairies during 2010 and 2011. Isolation flux chambers were used to measure direct emissions from specific dairy sources, and upwind/downwind ambient profiles were measured from ground level up to heights of 60 m. Samples were collected using a combination of canisters and sorbent tubes, and were analyzed by GC-MS. Additional in-situ measurements were made using infra-red photoaccoustic detectors and Diode Laser Absorption Spectroscopy. Temperature and ozone profiles up to 250 m above ground level were also measured using a tethersonde. Substantial fluxes of a number of VOCs including alcohols, volatile fatty acids and esters were observed at both sites. Implications of these measurements for regional air quality will be discussed.

  11. Volatile organic compounds from leaves litter.

    PubMed

    Isidorov, Valery; Jdanova, Maria

    2002-09-01

    Qualitative composition of volatile emissions of litter of five species of deciduous trees was investigated by GC-MS. The list of identified substances contains more than 70 organic compounds of various classes. It was established that the composition of components emitted by the litter into the gas phase greatly differs from that of essential oils extracted by hydrodistillation from turned leaves collected from trees during fall. It is suggested that most compounds found in litter emissions are products of vital activity of microorganisms decomposing it. The reported data indicate that after the vegetative period is over the decomposition processes of litter are important seasonal sources of reactive organic compounds under the forest canopy.

  12. Determination of volatile marker compounds of common coffee roast defects.

    PubMed

    Yang, Ni; Liu, Chujiao; Liu, Xingkun; Degn, Tina Kreuzfeldt; Munchow, Morten; Fisk, Ian

    2016-11-15

    Coffee beans from the same origin were roasted using six time-temperature profiles, in order to identify volatile aroma compounds associated with five common roast coffee defects (light, scorched, dark, baked and underdeveloped). Thirty-seven volatile aroma compounds were selected on the basis that they had previously been identified as potent odorants of coffee and were also identified in all coffee brew preparations; the relative abundance of these aroma compounds was then evaluated using gas chromatography mass spectrometry (GC-MS) with headspace solid phase micro extraction. Some of the 37 key aroma compounds were significantly changed in each coffee roast defect and changes in one marker compound was chosen for each defect type, that is, indole for light defect, 4-ethyl-2-methoxyphenol for scorched defect, phenol for dark defect, maltol for baked defect and 2,5-dimethylfuran for underdeveloped defect. The association of specific changes in aroma profiles for different roast defects has not been shown previously and could be incorporated into screening tools to enable the coffee industry quickly identify if roast defects occur during production. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Permeation of volatile compounds through starch films.

    PubMed

    Yilmaz, Gülden; Jongboom, Remy O J; Feil, Herman; van Dijk, Cees; Hennink, Wim E

    2004-01-01

    The aim of this study was to gain insight into the factors that affect the permeation of volatiles through starch films. These films were obtained by casting gelatinized starch/water/glycerol mixtures. The films were dried and conditioned under different conditions (temperature and relative humidity) resulting in films that vary in the degree of starch crystallinity and glycerol and water content. The permeation of two model volatiles (carvone and diacetyl) at 20 degrees C and at 30, 60, or 90% relative humidity (RH) was analyzed gravimetrically. Further, the solubility of the two model compounds (under conditions where the permeation experiments were carried out) was determined. From the obtained permeation and solubility data, the diffusion coefficients of these compounds in the different starch films were calculated. The crystallinity in the starch films increased with increasing water content of the films during preparation. The water content of the resulting films in turn increased with increasing glycerol and when the films were exposed to a higher RH during drying or conditioning. For films with the same composition, the flux for diacetyl was greater than for carvone. The solubilities of diacetyl and carvone were slightly dependent on the properties of the films. It was found that with increasing starch crystallinity the diffusion coefficient for both compounds decreases, which is probably due to the impermeability of starch crystallites. Interestingly, in films with about the same extent of crystallinity, the diffusion can be described with the free volume model, with water and glycerol determining the amount of free volume.

  14. Comparative volatile profiles in soy sauce according to inoculated microorganisms.

    PubMed

    Lee, Kyung Eun; Lee, Sang Mi; Choi, Yong Ho; Hurh, Byung Serk; Kim, Young-Suk

    2013-01-01

    We compared the volatile profiles in soy sauce according to inoculation with Tetragenococcus halophilus and/or Zygosaccharomyces rouxii. Totals of 107 and 81 volatiles were respectively identified by using solid-phase microextraction and solvent extraction. The various volatile compounds identified included acids, aldehydes, esters, ketones, furans and furan derivatives, and phenols. The major volatiles in the samples treated with T. halophilus were acetic acid, formic acid, benzaldehyde, methyl acetate, ethyl 2-hydroxypropanoate, 2-hydroxy-3-methyl-2-cyclopenten-1-one, and 4-hydroxy-3-methoxybenzaldehyde, while those in the samples inoculated with Z. rouxii were mainly ethanol, acetaldehyde, ethyl propanoate, 2/3-methylbutanol, 1-butanol, 2-phenylethanol, ethyl 2-methylpropanoate, and 4-hydroxy-2-ethyl-5-methyl-3(2H)-furanone. The results indicate that T. halophilus produced significant acid compounds and could affect the Z. rouxii activity, supporting the notion that yeasts and lactic acid bacteria respectively have different metabolic pathways of alcoholic fermentation and lactic acid fermentation, and produce different dominant volatile compounds in soy sauce.

  15. Volatile Compounds Produced by Lactobacillus paracasei During Oat Fermentation.

    PubMed

    Lee, Sang Mi; Oh, Jieun; Hurh, Byung-Serk; Jeong, Gwi-Hwa; Shin, Young-Keum; Kim, Young-Suk

    2016-12-01

    This study investigated the profiles of volatile compounds produced by Lactobacillus paracasei during oat fermentation using gas chromatography-mass spectrometry coupled with headspace solid-phase microextraction method. A total of 60 compounds, including acids, alcohols, aldehydes, esters, furan derivatives, hydrocarbons, ketones, sulfur-containing compounds, terpenes, and other compounds, were identified in fermented oat. Lipid oxidation products such as 2-pentylfuran, 1-octen-3-ol, hexanal, and nonanal were found to be the main contributors to oat samples fermented by L. paracasei with the level of 2-pentylfuran being the highest. In addition, the contents of ketones, alcohols, acids, and furan derivatives in the oat samples consistently increased with the fermentation time. On the other hand, the contents of degradation products of amino acids, such as 3-methylbutanal, benzaldehyde, acetophenone, dimethyl sulfide, and dimethyl disulfide, decreased in oat samples during fermentation. Principal component analysis (PCA) was applied to discriminate the fermented oat samples according to different fermentation times. The fermented oats were clearly differentiated on PCA plots. The initial fermentation stage was mainly affected by aldehydes, whereas the later samples of fermented oats were strongly associated with acids, alcohols, furan derivatives, and ketones. The application of PCA to data of the volatile profiles revealed that the oat samples fermented by L. paracasei could be distinguished according to fermentation time. © 2016 Institute of Food Technologists®.

  16. In vitro volatile organic compound profiling using GC×GC-TOFMS to differentiate bacteria associated with lung infections: a proof-of-concept study.

    PubMed

    Nizio, K D; Perrault, K A; Troobnikoff, A N; Ueland, M; Shoma, S; Iredell, J R; Middleton, P G; Forbes, S L

    2016-04-27

    Chronic pulmonary infections are the principal cause of morbidity and mortality in individuals with cystic fibrosis (CF). Due to the polymicrobial nature of these infections, the identification of the particular bacterial species responsible is an essential step in diagnosis and treatment. Current diagnostic procedures are time-consuming, and can also be expensive, invasive and unpleasant in the absence of spontaneously expectorated sputum. The development of a rapid, non-invasive methodology capable of diagnosing and monitoring early bacterial infection is desired. Future visions of real-time, in situ diagnosis via exhaled breath testing rely on the differentiation of bacteria based on their volatile metabolites. The objective of this proof-of-concept study was to investigate whether a range of CF-associated bacterial species (i.e. Pseudomonas aeruginosa, Burkholderia cenocepacia, Haemophilus influenzae, Stenotrophomonas maltophilia, Streptococcus pneumoniae and Streptococcus milleri) could be differentiated based on their in vitro volatile metabolomic profiles. Headspace samples were collected using solid phase microextraction (SPME), analyzed using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) and evaluated using principal component analysis (PCA) in order to assess the multivariate structure of the data. Although it was not possible to effectively differentiate all six bacteria using this method, the results revealed that the presence of a particular pattern of VOCs (rather than a single VOC biomarker) is necessary for bacterial species identification. The particular pattern of VOCs was found to be dependent upon the bacterial growth phase (e.g. logarithmic versus stationary) and sample storage conditions (e.g. short-term versus long-term storage at  -18 °C). Future studies of CF-associated bacteria and exhaled breath condensate will benefit from the approaches presented in this study and further

  17. Sunlight exclusion from Muscat grape alters volatile profiles during berry development.

    PubMed

    Zhang, Haohao; Fan, Peige; Liu, Cuixia; Wu, Benhong; Li, Shaohua; Liang, Zhenchang

    2014-12-01

    The effects of sunlight exclusion on the volatile profiles of grapes during different stages of berry development were investigated by placing clusters of grapes in special boxes. Terpenes and aldehydes were the main volatile compounds in the ripe 'Jingxiangyu' berries. Sunlight exclusion was found to change volatile profiles at any stage. Sunlight exclusion from berries significantly inhibited the synthesis and accumulation of terpenes, which contribute to the characteristic aroma of Muscat grapes. However, sunlight exclusion during berry formation and veraison promoted the accumulation of aldehydes, alcohols, and ketones during the ripening stage. These results may provide important information regarding the metabolism of volatile compounds in grapes.

  18. Volatile compounds in samples of cork and also produced by selected fungi.

    PubMed

    Barreto, M C; Vilas Boas, L; Carneiro, L C; San Romão, M V

    2011-06-22

    The production of volatile compounds by microbial communities of cork samples taken during the cork manufacturing process was investigated. The majority of volatiles were found in samples collected at two stages: resting after the first boiling and nontreated cork disks. Volatile profiles produced by microbiota in both stages are similar. The releasable volatile compounds and 2,4,6-trichloroanisole (TCA) produced in cork-based culture medium by five isolated fungal species in pure and mixed cultures were also analyzed by gas chromatography coupled with mass spectrometry (GC-MS).The results showed that 1-octen-3-ol and esters of fatty acids (medium chain length C8-C20) were the main volatile compounds produced by either pure fungal species or their mixture. Apparently, Penicillium glabrum is the main contributor to the overall volatile composition observed in the mixed culture. The production of releasable TCA on cork cannot be attributed to any of the assayed fungal isolates.

  19. A comparative qualitative study of the profile of volatile organic compounds associated with Salmonella contamination of packaged aged and fresh beef by HS-SPME/GC-MS.

    PubMed

    Bhattacharjee, Paramita; Panigrahi, Suranjan; Lin, Dongqing; Logue, Catherine M; Sherwood, Julie S; Doetkott, Curt; Marchello, Martin

    2011-02-01

    Vacuum packaged beef strip-loins (fresh and aged) were repackaged on polystyrene trays and over-wrapped with food grade cling film for the storage study. Several volatile compounds such as 3-methyl-1-butanol, 2,3-butanedione, 2-butanone, 3-hydroxy-2-butanone, acetic acid and a few hydrocarbons were detected in the headspace of these tray packaged fresh and aged beef strip loins both in the control and Salmonella typhimurium inoculated samples, in varying concentrations. These compounds were identified using manual headspace solid-phase microextraction (HS-SPME) in combination with gas chromatography/mass spectrometry (GC-MS) over a storage period of 4 days and samples were incubated at 20°C. No naturally occurring Salmonella was present in the control samples. Hexanal (r = 0.99), carbon dioxide (r = 0.98), 3-hydroxy-2-butanone (r = 0.93) and 2-methyl propane (r = 0.95) showed positive correlations with Salmonella population for fresh beef samples. In aged beef samples, 3-methyl-1-butanol (r = 0.99), 3-hydroxy-2-butanone (r = 0.98), carbon dioxide (r = 0.98) and acetic acid (r = 0.86) showed similar trends. In fresh beef samples, F values were significant at p < 0.05 for 3-hydroxy-2-butanone and for carbon dioxide with storage time for fresh beef samples; they were significant for 3-hydroxy-2-butanone, acetic acid and carbon dioxide for aged beef samples.

  20. Identification of volatile organic compounds in flowers of Astragalus lagopoides.

    PubMed

    Movafeghi, Ali; Delazar, Abbas; Amini, Majid; Asnaashari, Solmaz

    2012-01-01

    Composition of volatile organic compounds (VOCs) in flowers of Astragalus lagopoides was studied using a hydrodistillation extraction procedure coupled with gas chromatography-mass spectrometry. The analyses allowed the identification of a number of 25 compounds, among which the presence of several bioactive aromatic derivatives such as guaiacol, eugenol, linalool, α- and 4-terpineol as well as nerol was attention-grabbing. Moreover, some other compounds like cyclohexane, 2-bromoethyl with repellent function also appeared to be present in the flower. As a result, the floral VOCs profile of A. lagopoides might reflect an adaptation to attract specialised pollinator insects. These findings provide important information for advances in understanding the ecological and evolutionary perspectives of pollination biology of the giant genus Astragalus.

  1. Volatile Organic Compound Emissions by Agricultural Crops

    NASA Astrophysics Data System (ADS)

    Ormeno, E.; Farres, S.; Gentner, D.; Park, J.; McKay, M.; Karlik, J.; Goldstein, A.

    2008-12-01

    Biogenic Volatile Organic Compounds (BVOCs) participate in ozone and aerosol formation, and comprise a substantial fraction of reactive VOC emission inventories. In the agriculturally intensive Central Valley of California, emissions from crops may substantially influence regional air quality, but emission potentials have not been extensively studied with advanced instrumentation for many important crops. Because crop emissions may vary according to the species, and California emission inventories are constructed via a bottom-up approach, a better knowledge of the emission rate at the species-specific level is critical for reducing uncertainties in emission inventories and evaluating emission model performance. In the present study we identified and quantified the BVOCs released by dominant agricultural crops in California. A screening study to investigate both volatile and semivolatile BVOC fractions (oxygenated VOCs, isoprene, monoterepenes, sesquiterpenes, etc.) was performed for 25 crop species (at least 3 replicates plants each), including branch enclosures of woody species (e.g. peach, mandarin, grape, pistachio) and whole plant enclosures for herbaceous species (e.g. onion, alfalfa, carrot), through a dynamic cuvette system with detection by PTRMS, in-situ GCMS/FID, and collection on carbon-based adsorbents followed by extraction and GCMS analysis. Emission data obtained in this study will allow inclusion of these crops in BVOC emission inventories and air quality simulations.

  2. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    SciTech Connect

    John F. Schabron; Joseph F. Rovani Jr.; Theresa M. Bomstad

    2002-06-01

    Western Research Institute (WRI) initiated exploratory work towards the development of new field screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of carbon-halogen bonds. Commercially available heated diode and corona discharge leak detectors were procured and evaluated for halogenated VOC response. The units were modified to provide a digital readout of signal related to VOC concentration. Sensor response was evaluated with carbon tetrachloride and tetrachloroethylene (perchloroethylene, PCE), which represent halogenated VOCs with and without double bonds. The response characteristics were determined for the VOCs directly in headspace in Tedlar bag containers. Quantitation limits in air were estimated. Potential interferences from volatile hydrocarbons, such as toluene and heptane, were evaluated. The effect of humidity was studied also. The performance of the new devices was evaluated in the laboratory by spiking soil samples and monitoring headspace for halogenated VOCs. A draft concept of the steps for a new analytical method was outlined. The results of the first year effort show that both devices show potential utility for future analytical method development work towards the goal of developing a portable test kit for screening halogenated VOCs in the field.

  3. Comprehensive comparative analysis of volatile compounds in citrus fruits of different species.

    PubMed

    Zhang, Haipeng; Xie, Yunxia; Liu, Cuihua; Chen, Shilin; Hu, Shuangshuang; Xie, Zongzhou; Deng, Xiuxin; Xu, Juan

    2017-09-01

    The volatile profiles of fruit peels and juice sacs from 108 citrus accessions representing seven species were analyzed. Using GC-MS 162 and 107 compounds were determined in the peels and juice sacs, respectively. In the peels, monoterpene alcohols were accumulated in loose-skin mandarins; clementine tangerines and papedas were rich in sesquiterpene alcohols, sesquiterpenes, monoterpene alcohols and monoterpene aldehydes. β-pinene and sabinene were specifically accumulated in 4 of 5 lemon germplasms. Furthermore, concentrations of 34 distinctive compounds were selected to best represent the volatile profiles of seven species for HCA analysis, and the clustering results were in agreement with classic citrus taxonomy. Comparison of profiles from different growing seasons and production areas indicated that environmental factors play important roles in volatile metabolism. In addition, a few citrus germplasms that accumulated certain compounds were determined as promising breeding materials. Notably, volatile biosynthesis via MVA pathway in C. ichangensis 'Huaihua' was enhanced. Copyright © 2017. Published by Elsevier Ltd.

  4. 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

  5. Volatile Organic Compound Emissions from Humans Indoors.

    PubMed

    Tang, Xiaochen; Misztal, Pawel K; Nazaroff, William W; Goldstein, Allen H

    2016-12-06

    Research on the sources of indoor airborne chemicals has traditionally focused on outdoor air, building materials, furnishings, and activities such as smoking, cooking, and cleaning. Relatively little research has examined the direct role of occupant emissions, even though this source clearly contributes to indoor volatile organic compounds (VOCs) and influences indoor chemistry. In this work, we quantify occupant-related gaseous VOC emissions in a university classroom using a proton-transfer-reaction time-of-flight mass spectrometer. Time-resolved concentrations of VOCs in room air and supply air were measured continuously during occupied and unoccupied periods. The emission factor for each human-emitted VOC was determined by dividing the occupant-associated source rate by the corresponding occupancy. Among the most abundant species detected were compounds associated with personal care products. Also prominent were human metabolic emissions, such as isoprene, methanol, acetone, and acetic acid. Additional sources included human skin oil oxidation by ozone, producing compounds such as 4-oxopentanal (4-OPA) and 6-methyl-5-hepten-2-one (6-MHO). By mass, human-emitted VOCs were the dominant source (57%) during occupied periods in a well-ventilated classroom, with ventilation supply air the second most important (35%), and indoor nonoccupant emissions the least (8%). The total occupant-associated VOC emission factor was 6.3 mg h(-1) per person.

  6. Volatile Organic Compounds in the Global Atmosphere

    NASA Astrophysics Data System (ADS)

    Helmig, D.; Bottenheim, J.; Galbally, I. E.; Lewis, A.; Milton, M. J. T.; Penkett, S.; Plass-Duelmer, C.; Reimann, S.; Tans, P.; Thiel, S.

    2009-12-01

    Volatile organic compounds (VOCs) include saturated, unsaturated, and other substituted hydrocarbons. VOCs play an important role in the chemistry of the atmosphere by influencing ozone and hydroxyl radical (OH) concentrations and the conversion rates of nitrogen oxides (NO x ). Elevated levels of VOCs and NO x have led to an approximate doubling of ozone in the lower troposphere over the past couple of centuries, making tropospheric ozone the third most important anthropogenic greenhouse gas after carbon dioxide (CO2) and methane. Because of ozone's strong oxidizing properties, increases in tropospheric ozone are a concern for living systems on Earth. Ozone stresses and damages vegetation, resulting in a reduction of terrestrial CO2 sequestration. VOCs also serve as a source of atmospheric secondary organic aerosol (SOA), which influences the solar radiation budget and cloud droplet nucleation. Through these complex interactions, VOCs play an important role in air quality and climate.

  7. Volatilization of organic compounds from streams

    USGS Publications Warehouse

    Rathburn, R.E.; Tai, D.Y.

    1982-01-01

    Mass-transfer coefficients for the volatilization of ethylene and propane were correlated with the hydraulic and geometric properties of seven streams, and predictive equations were developed. The equations were evaluated using a normalized root-mean-square error as the criterion of comparison. The two best equations were a two-variable equation containing the energy dissipated per unit mass per unit time and the average depth of flow and a three-variable equation containing the average velocity, the average depth of flow, and the slope of the stream. Procedures for adjusting the ethylene and propane coefficients for other organic compounds were evaluated. These procedures are based on molecular diffusivity, molecular diameter, or molecular weight. Because of limited data, none of these procedures have been extensively verified. Therefore, until additional data become available, it is suggested that the mass-transfer coefficient be assumed to be inversely proportional to the square root of the molecular weight.

  8. Profiling of soil volatile organic compounds after long-term application of inorganic, organic and organic-inorganic mixed fertilizers and their effect on plant growth.

    PubMed

    Raza, Waseem; Mei, Xinlan; Wei, Zhong; Ling, Ning; Yuan, Jun; Wang, Jichen; Huang, Qiwei; Shen, Qirong

    2017-12-31

    The complexity of soil processes involved in the production, consumption and accumulation of volatile organic compounds (VOCs) makes hard to access the overall dynamics of VOCs in the soil. In this study, the field soil, applied with inorganic (CF), organic (OF) and inorganic-organic mixed (CFOF) fertilizers for ten years was evaluated for the emission of VOCs at different temperature and moisture levels. We identified 30-50 soil emitted VOCs representing the most common soil VOCs groups by using the solid-phase microextraction (SPME) fiber and gas chromatography-mass spectroscopy. The highest total emission of VOCs was found in OF treatment, but it was non-significantly different with CF treatment. The emission of VOCs was significantly increased with the decrease in moisture contents and increase in the temperature of the soil. Among different fertilizer treatments, the emission of VOCs was significantly higher in OF treatment at 5% moisture, and in CF and OF treatments at 35°C. Further, the VOCs emitted from soil treated with CFOF showed the highest increase in plant growth while CF and OF treatments showed similar results. The VOCs were also extracted from the soil using methanol to better understand the dynamics of VOCs. The abundance of VOCs extracted from the soil was 44-61%, while the richness was 65-70% higher than the VOCs emitted from the soil in different treatments. Taken together the results of emitted and extracted VOCs from the soil, we conclude that the fertilizers are able to discriminate among the VOC patterns of soil. In addition, most of the VOCs are retained in the soil and the emission of VOCs from soil depends on the type of VOCs, soil properties and environmental conditions; however, more research is required to find out better soil VOCs analysis methods. Copyright © 2017. Published by Elsevier B.V.

  9. Volatile Organic Compound Analysis in Istanbul

    NASA Astrophysics Data System (ADS)

    Ćapraz, Ö.; Deniz, A.; Öztürk, A.; Incecik, S.; Toros, H.; Coşkun, M.

    2012-04-01

    Volatile Organic Compound Analysis in Istanbul Ö. Çapraz1, A. Deniz1,3, A. Ozturk2, S. Incecik1, H. Toros1 and, M. Coskun1 (1) Istanbul Technical University, Faculty of Aeronautics and Astronautics, Department of Meteorology, 34469, Maslak, Istanbul, Turkey. (2) Istanbul Technical University, Faculty of Chemical and Metallurgical, Chemical Engineering, 34469, Maslak, Istanbul, Turkey. (3) Marmara Clean Air Center, Ministry of Environment and Urbanization, Nişantaşı, 34365, İstanbul, Turkey. One of the major problems of megacities is air pollution. Therefore, investigations of air quality are increasing and supported by many institutions in recent years. Air pollution in Istanbul contains many components that originate from a wide range of industrial, heating, motor vehicle, and natural emissions sources. VOC, originating mainly from automobile exhaust, secondhand smoke and building materials, are one of these compounds containing some thousands of chemicals. In spite of the risks to human health, relatively little is known about the levels of VOC in Istanbul. In this study, ambient air quality measurements of 32 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in Kağıthane (Golden Horn) region in Istanbul during the winter season of 2011 in order to develop the necessary scientific framework for the subsequent developments. Kağıthane creek valley is the source part of the Golden Horn and one of the most polluted locations in Istanbul due to its topographical form and pollutant sources in the region. In this valley, horizontal and vertical atmospheric motions are very weak. The target compounds most commonly found were benzene, toluene, xylene and ethyl benzene. Concentrations of total hydrocarbons ranged between 1.0 and 10.0 parts per billion, by volume (ppbv). Ambient air levels of halogenated hydrocarbons appeared to exhibit unique spatial variations and no single factor seemed to explain trends for this group of

  10. GLOBAL INVENTORY OF VOLATILE COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES

    EPA Science Inventory

    The report describes a global inventory anthropogenic volatile organic compound (VOC) emissions that includes a separate inventory for each of seven pollutant groups--paraffins, olefins, aromatics, formaldehyde, other aldehydes, other aromatics, and marginally reactive compounds....

  11. GLOBAL INVENTORY OF VOLATILE COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES

    EPA Science Inventory

    The report describes a global inventory anthropogenic volatile organic compound (VOC) emissions that includes a separate inventory for each of seven pollutant groups--paraffins, olefins, aromatics, formaldehyde, other aldehydes, other aromatics, and marginally reactive compounds....

  12. Volatile organic compounds sources and sinks in a wheat canopy. Analysis based on combined eddy-covariance fluxes, in-canopy profiles and chamber measurements with a PTR-TOF-Qi-MS

    NASA Astrophysics Data System (ADS)

    Loubet, Benjamin; Gonzaga, Lais; Buysse, Pauline; Ciuraru, Raluca; Lafouge, Florence; Decuq, Céline; Zurfluh, Olivier; Fortineau, Alain; Fanucci, Olivier; Sarda-Esteve, Roland; Zannoni, Nora; Truong, Francois; Boissard, Christophe; Gros, Valérie

    2017-04-01

    Volatile organic compounds (VOC) are essential drivers of atmospheric chemistry. Many VOCs are emitted from and deposited to ecosystems. While forests and grasslands have already been substantially studied, exchanges of VOCs with crops are less known, although these ecosystems represent more than 50% of the surface in France. In this study, we analyze sources and sinks of VOCs in a wheat field (at the ICOS FR-GRI site near Paris) at anthesis based on measurements of fluxes, concentration profiles and branch chambers. The VOCs were measured using a PTR-TOF-Qi-MS (where Qi stands for Quad Ion guide). Air was successively sampled through lines located at different heights within and above the canopy, of which one was used for Eddy Covariance and located near a sonic anemometer. Additional measurements included the standard ICOS meteorological data as well as leaf area index profiles and photosynthesis curves at several heights in the canopy. We report fluxes and profiles for more than 500 VOCs. The deposition velocities of depositing compounds are compared to the maximum exchange velocity and the ozone deposition velocity. The sources and sinks location and magnitude are evaluated by inverse Lagrangian modelling assuming no reaction and simple reaction schemes in the canopy. The sources and sinks of VOC in the canopy are interpreted in terms crop phenology and the potential for reaction with ozone and NOx is evaluated. This study takes place in the ADEME CORTEA COV3ER French project (http://www6.inra.fr/cov3er).

  13. EMISSION OF VOLATILE COMPOUNDS BY SEEDS UNDER DIFFERENT ENVIRONMENTAL CONDITIONS

    EPA Science Inventory

    Small mammals locate buried wet seeds more efficiently than buried dry seeds. This may be attributable to emission of volatile compounds by the seeds. To test this hypothesis I measured emission of volatile compounds from seeds of three plant species (Pinus contorta, Purshia tr...

  14. EMISSION OF VOLATILE COMPOUNDS BY SEEDS UNDER DIFFERENT ENVIRONMENTAL CONDITIONS

    EPA Science Inventory

    Small mammals locate buried wet seeds more efficiently than buried dry seeds. This may be attributable to emission of volatile compounds by the seeds. To test this hypothesis I measured emission of volatile compounds from seeds of three plant species (Pinus contorta, Purshia tr...

  15. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  16. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  17. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds. 60.582 Section 60.582 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Flexible Vinyl and Urethane Coating and Printing § 60.582 Standard for volatile organic compounds. (a)...

  18. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  19. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  20. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.602 Section 60.602 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Synthetic Fiber Production Facilities § 60.602 Standard for volatile organic compounds. On and after...

  1. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  2. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  3. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  4. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for volatile organic compounds. 60.452 Section 60.452 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Industrial Surface Coating: Large Appliances § 60.452 Standard for volatile organic compounds. On or...

  5. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.582 Section 60.582 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Flexible Vinyl and Urethane Coating and Printing § 60.582 Standard for volatile organic compounds. (a)...

  6. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  7. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.602 Section 60.602 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Synthetic Fiber Production Facilities § 60.602 Standard for volatile organic compounds. On and after...

  8. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  9. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds. 60.452 Section 60.452 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Industrial Surface Coating: Large Appliances § 60.452 Standard for volatile organic compounds. On or...

  10. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  11. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  12. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds. 60.452 Section 60.452 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Industrial Surface Coating: Large Appliances § 60.452 Standard for volatile organic compounds. On or...

  13. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.452 Section 60.452 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Industrial Surface Coating: Large Appliances § 60.452 Standard for volatile organic compounds. On or...

  14. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.582 Section 60.582 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Flexible Vinyl and Urethane Coating and Printing § 60.582 Standard for volatile organic compounds. (a)...

  15. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for volatile organic compounds. 60.582 Section 60.582 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Flexible Vinyl and Urethane Coating and Printing § 60.582 Standard for volatile organic compounds. (a)...

  16. 40 CFR 60.462 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date...

  17. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  18. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  19. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  20. 40 CFR 60.622 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected...

  1. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  2. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds. 60.602 Section 60.602 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Synthetic Fiber Production Facilities § 60.602 Standard for volatile organic compounds. On and after...

  3. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  4. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for volatile organic compounds. 60.602 Section 60.602 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Synthetic Fiber Production Facilities § 60.602 Standard for volatile organic compounds. On and after...

  5. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  6. 40 CFR 60.602 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds. 60.602 Section 60.602 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Synthetic Fiber Production Facilities § 60.602 Standard for volatile organic compounds. On and after...

  7. 40 CFR 60.582 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds. 60.582 Section 60.582 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Flexible Vinyl and Urethane Coating and Printing § 60.582 Standard for volatile organic compounds. (a)...

  8. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  9. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  10. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  11. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  12. 40 CFR 60.492 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Beverage Can Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after...

  13. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  14. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  15. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  16. 40 CFR 60.722 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds. 60.722 Section 60.722 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... volatile organic compounds. (a) Each owner or operator of any affected facility which is subject to...

  17. 40 CFR 60.452 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.452 Section 60.452 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Industrial Surface Coating: Large Appliances § 60.452 Standard for volatile organic compounds. On or...

  18. 40 CFR 60.712 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Magnetic Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or...

  19. 40 CFR 60.742 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Polymeric Coating of Supporting Substrates Facilities § 60.742 Standards for volatile organic compounds....

  20. Monitoring biogenic volatile compounds emitted by Eucalyptus citriodora using SPME.

    PubMed

    Zini, C A; Augusto, F; Christensen, T E; Smith, B P; Caramão, E B; Pawliszy, J

    2001-10-01

    A procedure to monitor BVOC emitted by living plants using SPME technique is presented. For this purpose, a glass sampling chamber was designed. This device was employed for the characterization of biogenic volatile compounds emitted by leaves of Eucalyptus citriodora. After extraction with SPME fibers coated with PDMS/ DVB, it was possible to identify or detect 33 compounds emitted by this plant. A semiquantitative approach was applied to monitor the behavior of the emitted BVOC during 9 days. Circadian profiles of the variation in the concentration of isoprene were plotted. Using diffusion-based SPME quantitation, a recently introduced analytical approach, with extraction times as short as 15 s, it was possible to quantify subparts-per-billion amounts of isoprene emitted by this plant.

  1. Difference in volatile profile between pericarp tissue and locular gel in tomato fruit

    USDA-ARS?s Scientific Manuscript database

    Aroma, a complex mixture of volatile compounds, plays an important role in the perception and acceptability of tomato products by consumers. Numerous studies have reported volatile profiles in tomatoes based on measurement of the whole fruit or pericarp tissue, however, little is understood regardin...

  2. 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.

  3. Analysis of volatile organic compounds from illicit cocaine samples

    SciTech Connect

    Robins, W.H.; Wright, B.W.

    1994-07-01

    Detection of illicit cocaine hydrochloride shipments can be improved if there is a greater understanding of the identity and quantity of volatile compounds present. This study provides preliminary data concerning the volatile organic compounds detected in a limited Set of cocaine hydrochloride samples. In all cases, cocaine was one of the major volatile compounds detected. Other tropeines were detected in almost all samples. Low concentrations of compounds that may be residues of processing solvents were observed in some samples. The equilibrium emissivity of. cocaine from cocaine hydrochloride was investigated and a value of 83 parts-per-trillion was determined.

  4. Thermal desorption comprehensive two-dimensional gas chromatography coupled to variable-energy electron ionization time-of-flight mass spectrometry for monitoring subtle changes in volatile organic compound profiles of human blood.

    PubMed

    Dubois, Lena M; Perrault, Katelynn A; Stefanuto, Pierre-Hugues; Koschinski, Stefan; Edwards, Matthew; McGregor, Laura; Focant, Jean-François

    2017-06-09

    Blood is a matrix with high potential for forensic investigations and human rescue. Its volatile signature can be used in search exercises to locate injured or deceased individuals. Little is known, however, about the volatile organic compound (VOC) profile of blood, except that it is complex and varies while blood ages. In the present study, we used thermal desorption (TD) and comprehensive two-dimensional gas chromatography (GCxGC) coupled to variable-energy electron ionization time-of-flight mass spectrometry (TOFMS) to monitor VOC signatures of human blood. A highly complex reference standard (Century Mix) containing 108 compounds of various chemical functionalities and several homologue series of compounds was used for the purpose of transposing our previously developed cryogenically modulated GCxGC-TOFMS methods into the use of a reverse fill/flush (RFF) flow modulator. The average peak width at half height was 340ms and the average tailing factor was 1.16. Light VOCs (down to C4) were effectively flow modulated and exhibited minimal breakthrough over a large dynamic range spanning four orders of magnitude. Mass spectrometric detection was performed using electron impact ionization (EI) carried out at 70eV and lower energies (12, 14, and 16eV). The use of variable-energy (ve) EI allowed mass spectra to be produced with less fragmentation and an increased presence of structurally significant ions and the molecular ion. This provided additional confidence in peak assignments, especially for closely eluting isomers often observed in the profiling of the headspace of blood. Variable-energy EI TD-GCxGC-TOFMS blood data sets were statistically processed using principal component analyses (PCA) and hierarchical cluster analyses (HCA). These techniques demonstrated that the effect of aging was greater than the inter-individual variation on the blood VOC profile. The combination of retention indices, low and high EI MS spectra served as a strong basis to gain more

  5. Tropospheric volatile organic compounds in China.

    PubMed

    Guo, H; Ling, Z H; Cheng, H R; Simpson, I J; Lyu, X P; Wang, X M; Shao, M; Lu, H X; Ayoko, G; Zhang, Y L; Saunders, S M; Lam, S H M; Wang, J L; Blake, D R

    2017-01-01

    Photochemical smog, characterized by high concentrations of ozone (O3) and fine particles (PM2.5) in the atmosphere, has become one of the top environmental concerns in China. Volatile organic compounds (VOCs), one of the key precursors of O3 and secondary organic aerosol (SOA) (an important component of PM2.5), have a critical influence on atmospheric chemistry and subsequently affect regional and global climate. Thus, VOCs have been extensively studied in many cities and regions in China, especially in the North China Plain, the Yangtze River Delta and the Pearl River Delta regions where photochemical smog pollution has become increasingly worse over recent decades. This paper reviews the main studies conducted in China on the characteristics and sources of VOCs, their relationship with O3 and SOA, and their removal technology. This paper also provides an integrated literature review on the formulation and implementation of effective control strategies of VOCs and photochemical smog, as well as suggestions for future directions of VOCs study in China.

  6. Volatile organic compound remedial action project

    SciTech Connect

    1991-12-01

    This Environmental Assessment (EA) reviews a proposed project that is planned to reduce the levels of volatile organic compound (VOC) contaminants present in the Mound domestic water supply. The potable and industrial process water supply for Mound is presently obtained from a shallow aquifer via on-site production wells. The present levels of VOCs in the water supply drawn from the on-site wells are below the maximum contaminant levels (MCLs) permissible for drinking water under Safe Drinking Water Act (SDWA; 40 CFR 141); however, Mound has determined that remedial measures should be taken to further reduce the VOC levels. The proposed project action is the reduction of the VOC levels in the water supply using packed tower aeration (PTA). This document is intended to satisfy the requirements of the National Environmental Policy Act (NEPA) of 1969 and associated Council on Environmental Quality regulations (40 CFR parts 1500 through 1508) as implemented through U.S. Department of Energy (DOE) Order 5440.1D and supporting DOE NEPA Guidelines (52 FR 47662), as amended (54 FR 12474; 55 FR 37174), and as modified by the Secretary of Energy Notice (SEN) 15-90 and associated guidance. As required, this EA provides sufficient information on the probable environmental impacts of the proposed action and alternatives to support a DOE decision either to prepare an Environmental Impact Statement (EIS) or issue a Finding of No Significant Impact (FONSI).

  7. Nitrate radicals and biogenic volatile organic compounds ...

    EPA Pesticide Factsheets

    Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 decades, during which time a large body of research has emerged from laboratory, field, and modeling studies. NO3-BVOC reactions influence air quality, climate and visibility through regional and global budgets for reactive nitrogen (particularly organic nitrates), ozone, and organic aerosol. Despite its long history of research and the significance of this topic in atmospheric chemistry, a number of important uncertainties remain. These include an incomplete understanding of the rates, mechanisms, and organic aerosol yields for NO3-BVOC reactions, lack of constraints on the role of heterogeneous oxidative processes associated with the NO3 radical, the difficulty of characterizing the spatial distributions of BVOC and NO3 within the poorly mixed nocturnal atmosphere, and the challenge of constructing appropriate boundary layer schemes and non-photochemical mechanisms for use in state-of-the-art chemical transport and chemistry–climate models. This review is the result of a workshop of the same title held at the Georgia Institute of Technology in June 2015. The first half of the review summarizes the current literature on NO3-BVOC chemistry, with a particular focus on recent advances in

  8. Biogenic volatile organic compounds - small is beautiful

    NASA Astrophysics Data System (ADS)

    Owen, S. M.; Asensio, D.; Li, Q.; Penuelas, J.

    2012-12-01

    While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to <2m above ground level. Emissions at leaf scale are well documented and widely presented, and are not discussed here. Instead we describe some details of recent research on rhizosphere bVOCs, and bVOCs associated with pollination of flowers. Although bVOC emissions from soil surfaces are small, bVOCs are exuded by roots of some plant species, and can be extracted from decaying litter. Naturally occurring monoterpenes in the rhizosphere provide a specialised carbon source for micro-organisms, helping to define the micro-organism community structure, and impacting on nutrient cycles which are partly controlled by microorganisms. Naturally occurring monoterpenes in the soil system could also affect the aboveground structure of ecosystems because of their role in plant defence strategies and as mediating chemicals in allelopathy. A gradient of monoterpene concentration was found in soil around Pinus sylvestris and Pinus halepensis, decreasing with distance from the tree. Some compounds (α-pinene, sabinene, humulene and caryophyllene) in mineral soil were linearly correlated with the total amount of each compound in the overlying litter, indicating that litter might be the dominant source of these compounds. However, α-pinene did not fall within the correlation, indicating a source other than litter, probably root exudates. We also show that rhizosphere bVOCs can be a carbon source for soil microbes. In a horizontal gradient from Populus tremula trees, microbes closest to the tree trunk were better enzymatically equipped to metabolise labeled monoterpene substrate. Monoterpenes can also increase the

  9. 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.

  10. Analysis of volatile organic compounds. [trace amounts of organic volatiles in gas samples

    NASA Technical Reports Server (NTRS)

    Zlatkis, A. (Inventor)

    1977-01-01

    An apparatus and method are described for reproducibly analyzing trace amounts of a large number of organic volatiles existing in a gas sample. Direct injection of the trapped volatiles into a cryogenic percolum provides a sharply defined plug. Applications of the method include: (1) analyzing the headspace gas of body fluids and comparing a profile of the organic volatiles with standard profiles for the detection and monitoring of disease; (2) analyzing the headspace gas of foods and beverages and comparing the profile with standard profiles to monitor and control flavor and aroma; and (3) analyses for determining the organic pollutants in air or water samples.

  11. Microbiological characterisation and volatiles profile of model, ex-novo, and traditional Italian white wheat sourdoughs.

    PubMed

    Ripari, Valery; Cecchi, Teresa; Berardi, Enrico

    2016-08-15

    The interplay of sourdough microbiology and generated volatile compounds that define its sensory characteristics was studied. In order to detail the flavour generating potential of microorganisms, eight single-strain dough fermentations were studied, four of them never investigated before. Moreover, for the first time, both ex-novo and traditional wheat sourdoughs were investigated and compared to chemically acidified dough. HS-SPME-GC-MS was used to sample and analyse volatile compounds, some of which have never been detected before in sourdoughs. Alcohols, esters, carbonyl compounds, and acids mainly characterised the volatile profiles. Different sourdough microbiota resulted in different volatile profiles. PCA indicated that samples could be clustered according to their specific microbiota. Production of aroma compounds was strain-specific, confirming previous findings. This study can contribute to the management of desirable features and differentiate specialty products, as well as selecting new, suitable, sourdoughs after microbial screening. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Breath measurements as volatile organic compound biomarkers.

    PubMed Central

    Wallace, L; Buckley, T; Pellizzari, E; Gordon, S

    1996-01-01

    A brief review of the uses of breath analysis in studies of environmental exposure to volatile organic compounds (VOCs) is provided. The U.S. Environmental Protection Agency's large-scale Total Exposure Assessment Methodology Studies have measured concentrations of 32 target VOCs in the exhaled breath of about 800 residents of various U.S. cities. Since the previous 12-hr integrated personal air exposures to the same chemicals were also measured, the relation between exposure and body burden is illuminated. Another major use of the breath measurements has been to detect unmeasured pathways of exposure; the major impact of active smoking on exposure to benzene and styrene was detected in this way. Following the earlier field studies, a series of chamber studies have provided estimates of several important physiological parameters. Among these are the fraction, f, of the inhaled chemical that is exhaled under steady-state conditions and the residence times. tau i in several body compartments, which may be associated with the blood (or liver), organs, muscle, and fat. Most of the targeted VOCs appear to have similar residence times of a few minutes, 30 min, several hours, and several days in the respective tissue groups. Knowledge of these parameters can be helpful in estimating body burden from exposure or vice versa and in planning environmental studies, particularly in setting times to monitor breath in studies of the variation with time of body burden. Improvements in breath methods have made it possible to study short-term peak exposure situations such as filling a gas tank or taking a shower in contaminated water. PMID:8933027

  13. Breath measurements as volatile organic compound biomarkers.

    PubMed

    Wallace, L; Buckley, T; Pellizzari, E; Gordon, S

    1996-10-01

    A brief review of the uses of breath analysis in studies of environmental exposure to volatile organic compounds (VOCs) is provided. The U.S. Environmental Protection Agency's large-scale Total Exposure Assessment Methodology Studies have measured concentrations of 32 target VOCs in the exhaled breath of about 800 residents of various U.S. cities. Since the previous 12-hr integrated personal air exposures to the same chemicals were also measured, the relation between exposure and body burden is illuminated. Another major use of the breath measurements has been to detect unmeasured pathways of exposure; the major impact of active smoking on exposure to benzene and styrene was detected in this way. Following the earlier field studies, a series of chamber studies have provided estimates of several important physiological parameters. Among these are the fraction, f, of the inhaled chemical that is exhaled under steady-state conditions and the residence times. tau i in several body compartments, which may be associated with the blood (or liver), organs, muscle, and fat. Most of the targeted VOCs appear to have similar residence times of a few minutes, 30 min, several hours, and several days in the respective tissue groups. Knowledge of these parameters can be helpful in estimating body burden from exposure or vice versa and in planning environmental studies, particularly in setting times to monitor breath in studies of the variation with time of body burden. Improvements in breath methods have made it possible to study short-term peak exposure situations such as filling a gas tank or taking a shower in contaminated water.

  14. Volatile organic compounds released by blowfly larvae and pupae: new perspectives in forensic entomology.

    PubMed

    Frederickx, C; Dekeirsschieter, J; Brostaux, Y; Wathelet, J-P; Verheggen, F J; Haubruge, E

    2012-06-10

    To evaluate postmortem intervals (PMIs), one should take into account the determined age of necrophagous flies present on the cadaver. However, PMI determination needs further improvement, and rapid and accurate approaches have therefore to be developed. While previous studies have focussed on insect cuticular hydrocarbons, here we explore the volatile profile released by larvae and pupae of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). We monitored changes in volatile compounds daily, by headspace solid-phase microextraction, followed by gas chromatography-mass spectrometry. Branched and unbranched hydrocarbons, alcohols, esters and acids were identified, and the volatile profile was shown to vary, in both composition and quantity, with the age of the larva/pupa under investigation. We concluded, based on the analysis of the released volatile organic compounds, that it is possible to increase the accuracy of the estimated PMI, through improved estimation of the age of blowflies present on the cadaver.

  15. Effect of the type of oil on the evolution of volatile compounds of taralli during storage.

    PubMed

    Giarnetti, Mariagrazia; Caponio, Francesco; Paradiso, Vito M; Summo, Carmine; Gomes, Tommaso

    2012-03-01

    Baking process leads to a huge quantity of newly formed volatile compounds, which play a major role in developing the flavor of the final product. The aim of this work was to investigate on the evolution of the volatile profile of taralli as a function of both the kind of oil used in the dough and the storage time. The volatile compounds from the taralli were extracted by headspace solid-phase microextraction and analyzed by gas-chromatography/mass spectrometry (GC/MS). Forty-four volatile compounds were identified in taralli, most of which produced by thermically induced reactions occurring during baking process, such as volatiles deriving from Maillard reaction and/or sugar degradation and lipid oxidation. The results obtained demonstrated the essential role played by the type of oil on the formation and on the release of volatile compounds. The volatile compounds significantly increased during storage and their individual levels were in most cases significantly lower in taralli made with extra virgin olive oil than in those made with refined oils. Finally, the taralli made with extra virgin olive oil, compared with those prepared with other vegetable oils, showed to be more resistant to oxidation, probably due to the presence of natural antioxidants.

  16. 40 CFR 60.392 - Standards for volatile organic compounds

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for volatile organic compounds 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  17. 40 CFR 60.392 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for volatile organic compounds. 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  18. 40 CFR 60.392 - Standards for volatile organic compounds

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for volatile organic compounds 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  19. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.432 Section 60.432 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Graphic Arts Industry: Publication Rotogravure Printing § 60.432 Standard for volatile organic...

  20. 40 CFR 60.392 - Standards for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  1. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  2. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds. 60.432 Section 60.432 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Graphic Arts Industry: Publication Rotogravure Printing § 60.432 Standard for volatile organic...

  3. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds. 60.432 Section 60.432 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Graphic Arts Industry: Publication Rotogravure Printing § 60.432 Standard for volatile organic...

  4. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for volatile organic compounds. 60.432 Section 60.432 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Graphic Arts Industry: Publication Rotogravure Printing § 60.432 Standard for volatile organic...

  5. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  6. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  7. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  8. 40 CFR 60.442 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile...

  9. 40 CFR 60.432 - Standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.432 Section 60.432 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Graphic Arts Industry: Publication Rotogravure Printing § 60.432 Standard for volatile organic...

  10. 40 CFR 60.392 - Standards for volatile organic compounds

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds 60.392 Section 60.392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic...

  11. BIOCONCENTRATION FACTORS FOR VOLATILE ORGANIC COMPOUNDS IN VEGETATION

    EPA Science Inventory

    Samples of air and leaves were taken at the University of Nevada-Las Vegas campus and analyzed for volatile organic compounds using vacuum distillation coupled with gas chromatography/mass spectrometry. The data were used to estimate the bioconcentration of volatile organic compo...

  12. Volatile organic sulfur compounds in a stratified lake.

    PubMed

    Hu, Haiying; Mylon, Steven E; Benoit, Gaboury

    2007-03-01

    Three volatile organic sulfur compounds (VOSCs), dimethyl sulfide (DMS), carbon disulfide (CS(2)), and dimethyl disulfide (DMDS), were detected in the stratified water column of a lake (Linsley Pond) in Connecticut. The compounds DMS and DMDS appeared in both the oxic and the anoxic portions of the water column, CS(2) was primarily found in anoxic hypolimnion. Algal metabolism and/or bacterial degradation of sulfur-containing amino acids or other organic materials are potential sources of VOSCs in the oxic lake water. Reactions of hydrogen sulfide with organic compounds and microbial degradation of organic matter may be responsible for the production of VOSCs in the anoxic lake water. The vertical distribution patterns of these three VOSCs varied from month to month in the summer, but the daily profiles obtained in one 5-day period in the summer displayed consistency. No clear diurnal pattern for any of the three VOSCs was observed. Based on observation that these VOSCs were not present in surface and near surface waters of Linsley Pond, freshwater inputs of reduced sulfur compounds to the atmosphere may be insignificant.

  13. Comparison of volatile compounds in water- and oil-soluble annatto (Bixa orellana L.) extracts.

    PubMed

    Galindo-Cuspinera, Verónica; Lubran, Meryl B; Rankin, Scott A

    2002-03-27

    Annatto is a natural food colorant extracted from the seeds of the Bixa orellana L. plant. Annatto is used in Latin American cuisine to add a deep red color as well as distinctive flavor notes to fish, meat, and rice dishes. In the United States, annatto extracts are primarily used to impart orange/yellow hues to cheese and other dairy foods. The objective of this study was to identify and compare volatile compounds present in water- and oil-soluble annatto extracts. Volatile compounds were recovered using dynamic headspace-solvent desorption sampling and analyzed using GC-MS. Compounds were identified by comparison to a mass spectral database, Kovats indexes, and retention times of known standards. Of the 107 compounds detected, 56 compounds were tentatively identified and 51 were positively identified. Volatile profile differences exist between water- and oil- soluble extracts, and annatto extracts contain odorants with the potential to influence food aroma.

  14. SEPARATION OF VOLATILE ORGANIC COMPOUNDS FROM SURFACTANT SOLUTIONS BY PERVAPORATION

    EPA Science Inventory

    Pervaporation is gradually becoming an accepted and practical method for the recovery of volatile organic compounds (VOCs) from aqueous process and waste streams. As the technolog has matured, new applications for pervaporation have emerged. One such application is the separati...

  15. SEPARATION OF VOLATILE ORGANIC COMPOUNDS FROM SURFACTANT SOLUTIONS BY PERVAPORATION

    EPA Science Inventory

    Pervaporation is gradually becoming an accepted and practical method for the recovery of volatile organic compounds (VOCs) from aqueous process and waste streams. As the technolog has matured, new applications for pervaporation have emerged. One such application is the separati...

  16. Studies on volatile organic compounds of Tuber borchii and T. asa-foetida.

    PubMed

    D'Auria, Maurizio; Rana, Gian Luigi; Racioppi, Rocco; Laurita, Alessandro

    2012-10-01

    Ascomata of two truffle species, Tuber borchii and T. asa-foetida, both naturally growing in woodlands of the Basilicata region (southern Italy), were identified on the basis of ascospore morphology and compared under a volatile organic compound profile to determine the particular volatile organic compounds that characterize each taxon. Solid-phase microextraction-gas chromatography-mass spectrometry analysis of the samples showed the presence of 1-methyl-1,3-butadiene as a primary component in both truffles. T. asa-foetida showed a compound, toluene, not present in T. borchii, which creates the penetrating "solvent" smell of the truffle.

  17. Can volatile organic compounds be markers of sea salt?

    PubMed

    Silva, Isabel; Coimbra, Manuel A; Barros, António S; Marriott, Philip J; Rocha, Sílvia M

    2015-02-15

    Sea salt is a handmade food product that is obtained by evaporation of seawater in saltpans. During the crystallisation process, organic compounds from surroundings can be incorporated into sea salt crystals. The aim of this study is to search for potential volatile markers of sea salt. Thus, sea salts from seven north-east Atlantic Ocean locations (France, Portugal, Continental Spain, Canary Islands, and Cape Verde) were analysed by headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. A total of 165 compounds were detected, ranging from 32 to 71 compounds per salt. The volatile composition revealed the variability and individuality of each salt, and a set of ten compounds were detected in all samples. From these, seven are carotenoid-derived compounds that can be associated with the typical natural surroundings of ocean hypersaline environment. These ten compounds are proposed as potential volatile markers of sea salt.

  18. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    SciTech Connect

    John F. Schabron; Joseph F. Rovani, Jr.; Theresa M. Bomstad

    2003-07-01

    Western Research Institute (WRI) is continuing work toward the development of new screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of halogens. In prior work, the devices were tested for response to carbon tetrachloride, heptane, toluene, and water vapors. In the current work, sensor response was evaluated with sixteen halogenated VOCs relative to carbon tetrachloride. The results show that the response of the various chlorinated VOCs is within an order of magnitude of the response to carbon tetrachloride for each of the sensors. Thus, for field screening a single response factor can be used. Both types of leak detectors are being further modified to provide an on-board LCD signal readout, which is related to VOC concentration. The units will be fully portable and will operate with 115-V line or battery power. Signal background, noise level, and response data on the Bacharach heated diode detector and the TIF corona discharge detector show that when the response curves are plotted against the log of concentration, the plot is linear to the upper limit for the particular unit, with some curvature at lower levels. When response is plotted directly against concentration, the response is linear at the low end and is curved at the high end. The dynamic ranges for carbon tetrachloride of the two devices from the lower detection limit (S/N=2) to signal saturation are 4-850 vapor parts per million (vppm) for the corona discharge unit and 0.01-70 vppm for the heated diode unit. Additional circuit modifications are being made to lower the detection limit and increase the dynamic response range of the corona discharge unit. The results indicate that both devices show potential utility for future analytical method development work toward

  19. Fate of Volatile Organic Compounds in Constructed Wastewater Treatment Wetlands

    USGS Publications Warehouse

    Keefe, S.H.; Barber, L.B.; Runkel, R.L.; Ryan, J.N.

    2004-01-01

    The fate of volatile organic compounds was evaluated in a wastewater-dependent constructed wetland near Phoenix, AZ, using field measurements and solute transport modeling. Numerically based volatilization rates were determined using inverse modeling techniques and hydraulic parameters established by sodium bromide tracer experiments. Theoretical volatilization rates were calculated from the two-film method incorporating physicochemical properties and environmental conditions. Additional analyses were conducted using graphically determined volatilization rates based on field measurements. Transport (with first-order removal) simulations were performed using a range of volatilization rates and were evaluated with respect to field concentrations. The inverse and two-film reactive transport simulations demonstrated excellent agreement with measured concentrations for 1,4-dichlorobenzene, tetrachloroethene, dichloromethane, and trichloromethane and fair agreement for dibromochloromethane, bromo-dichloromethane, and toluene. Wetland removal efficiencies from inlet to outlet ranged from 63% to 87% for target compounds.

  20. Infusion of volatile flavor compounds into low-density polyethylene.

    PubMed

    Avison, S J; Gray, D A; Davidson, G M; Taylor, A J

    2001-01-01

    Supercritical fluids can extract components from some matrixes (e.g., fat and flavors from food) as well as infusing additives into synthetic polymer matrixes. To study the feasibility of infusing flavors into matrixes as a potential flavoring mechanism, a wide range of volatile flavor compounds was infused into a well-defined synthetic polymer (low-density polyethylene) using supercritical carbon dioxide. The polymer was then extracted, and the amount of infused compound was determined. The effects of time, temperature, pressure, rate of depressurization, volatile concentration, and volatile properties on the degree of infusion were studied. Infusion with supercritical carbon dioxide achieved much higher loadings of the polymer (0.01 to 6.87 mg/g LDPE, depending on the volatile molecule being infused) compared to those achieved by static diffusion. Forty-five volatiles were infused, from which a model was developed to predict infusion as a function of certain physicochemical properties.

  1. Quantitative Profiling of Ester Compounds Using HS-SPME-GC-MS and Chemometrics for Assessing Volatile Markers of the Second Fermentation in Bottle.

    PubMed

    Muñoz-Redondo, José Manuel; Cuevas, Francisco Julián; León, Juan Manuel; Ramírez, Pilar; Moreno-Rojas, José Manuel; Ruiz-Moreno, María José

    2017-04-05

    A quantitative approach using HS-SPME-GC-MS was performed to investigate the ester changes related to the second fermentation in bottle. The contribution of the type of base wine to the final wine style is detailed. Furthermore, a discriminant model was developed based on ester changes according to the second fermentation (with 100% sensitivity and specificity values). The application of a double-check criteria according to univariate and multivariate analyses allowed the identification of potential volatile markers related to the second fermentation. Some of them presented a synthesis-ratio around 3-fold higher after this period and they are known to play a key role in wine aroma. Up to date, this is the first study reporting the role of esters as markers of the second fermentation. The methodology described in this study confirmed its suitability for the wine aroma field. The results contribute to enhance our understanding of this fermentative step.

  2. Emerging site characterization technologies for volatile organic compounds

    SciTech Connect

    Rohay, V.J.; Last, G.V.

    1992-05-01

    A Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) expedited response action (ERA) has been initiated at Hanford Site`s 200 West Area for the removal of carbon tetrachloride from the unsaturated soils. In coordination with the ERA, innovative technology demonstrations are being conducted as part of DOE`s Volatile Organic Compounds -- Arid Integrated Demonstration in an effort to improve upon baseline technologies. Improved methods for accessing, sampling, and analyzing soil and soil-vapor contaminants is a high priority. Sonic drilling is being evaluated as an alternative to cable-tool drilling, while still providing the advantages of reliability, containment, and waste minimization. Applied Research Associates, Inc. used their cone penetrometer in the 200 West Area to install a permanent soil-gas monitoring probe and to collect soil-gas profile data. However, successful application of this technology will require the development of an improved ability to penetrate coarse gravel units. A Science and Engineering Associates Membrane Instrumentation and Sampling Technique (SEAMIST) system designed for collecting in situ soil samples and air permeability data in between drilling runs at variable depths is being tested in 200 West Area boreholes. Analytical technologies scheduled for testing include supercritical fluid extraction and analysis for non- and semi-volatile organic co-contaminants and an unsaturated flow apparatus developed by Washington State University for the measurement of transport parameters.

  3. Emerging site characterization technologies for volatile organic compounds

    SciTech Connect

    Rohay, V.J.; Last, G.V.

    1992-05-01

    A Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) expedited response action (ERA) has been initiated at Hanford Site's 200 West Area for the removal of carbon tetrachloride from the unsaturated soils. In coordination with the ERA, innovative technology demonstrations are being conducted as part of DOE's Volatile Organic Compounds -- Arid Integrated Demonstration in an effort to improve upon baseline technologies. Improved methods for accessing, sampling, and analyzing soil and soil-vapor contaminants is a high priority. Sonic drilling is being evaluated as an alternative to cable-tool drilling, while still providing the advantages of reliability, containment, and waste minimization. Applied Research Associates, Inc. used their cone penetrometer in the 200 West Area to install a permanent soil-gas monitoring probe and to collect soil-gas profile data. However, successful application of this technology will require the development of an improved ability to penetrate coarse gravel units. A Science and Engineering Associates Membrane Instrumentation and Sampling Technique (SEAMIST) system designed for collecting in situ soil samples and air permeability data in between drilling runs at variable depths is being tested in 200 West Area boreholes. Analytical technologies scheduled for testing include supercritical fluid extraction and analysis for non- and semi-volatile organic co-contaminants and an unsaturated flow apparatus developed by Washington State University for the measurement of transport parameters.

  4. Volatile organic compounds and some very volatile organic compounds in new and recently renovated buildings in Switzerland

    NASA Astrophysics Data System (ADS)

    Rothweiler, Heinz; Wäger, Patrick A.; Schlatter, Christian

    Indoor air in new of recently renovated buildings was analysed by using different sorbents and analytical methods. Increased values of total volatile organic compounds (TVOC) were found on Tenax TA (1.6-31.7 mg m -3). Compared to older buildings, the amount of oxygen-containing compounds (aldehydes, ketones, alcohols) especially was elevated. High hexanal concentrations were measured in a significant amount of the houses. Differences of compound patterns were found from building to building. Complaints about discomfort and negative health effects are expected due to volatile organic compounds (VOC) and very volatile organic compounds (VVOC), as well as from low natural ventilation rates in some newly occupied buildings. Odorous compounds (naphthalene, higher aldehydes and alcohols, capronic acid, etc.) were found mainly, but some irritants and suspected sensitizing agents were also found. At the present state of our investigation chemicals causing other known toxic effects do not seem to increase the toxic risk substantially.

  5. Gas chromatography of volatile organic compounds

    NASA Technical Reports Server (NTRS)

    Zlatkis, A.

    1973-01-01

    System has been used for problems such as analysis of volatile metabolities in human blood and urine, analysis of air pollutants, and in tobacco smoke chemistry. Since adsorbent is reusable after porper reconditioning, method is both convenient and economical. System could be used for large scale on-site sampling programs in which sample is shipped to central location for analysis.

  6. Volatile profile of breast milk subjected to high-pressure processing or thermal treatment.

    PubMed

    Contador, R; Delgado, F J; García-Parra, J; Garrido, M; Ramírez, R

    2015-08-01

    The effect of Holder pasteurisation (HoP) (62.5°C for 30 min) or high-pressure treatments (400 or 600 MPa for 3 or 6 min) on the volatile compound profile of human breast milk was evaluated, in order to compare both preservation technologies. A total of 46 different volatile compounds was found in milk samples. The most abundant compounds detected were aliphatic hydrocarbons. In general, the effect of some high-pressure treatments on the volatile profile of human milk was less intense than that caused by HoP. The treatments at 400 and 600 MPa for 3 min maintained the volatile compounds at similar levels to those found in control milk samples. However, the application of 600 MPa for 6 min changed the original volatile compounds of human milk, even more than HoP. Since, HPP at 400 or 600 MPa for 3 min preserved the original volatile compounds of human milk, this novel process may be an alternative to thermal pasteurisation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Volatile carbonylic compounds in downtown Santiago, Chile.

    PubMed

    Rubio, María A; Zamorano, Natalia; Lissi, Eduardo; Rojas, Alicia; Gutiérrez, Luis; von Baer, Dietrich

    2006-02-01

    Formaldehyde, acetaldehyde, acetone, propanal, butanal, 2-butenal, 3-methylbutanal, hexanal, benzaldehyde, 2-methylbenzaldehyde, and 2,5-dimethylbenzaldehyde were measured during six spring days at downtown Santiago de Chile. Measurements were performed 24h/day and averaged over three hour periods. The averages of the maxima (ppbv) were, formaldehyde: 3.9+/-1.4; butanal: 3.3+/-3.4; acetaldehyde: 3.0+/-0.9; acetone: 2.4+/-1.0; 2-butenal: 0.56+/-0.52; propanal: 0.46+/-0.21; benzaldehyde: 0.34+/-0.3; 3-butanal: 0.11+/-0.05; hexanal: 0.11+/-0.08; 2-methylbenzaldehyde: 0.08+/-0.05; 2,5-dimethylbenzaldehyde: 0.05+/-0.03. Aliphatic aldehydes (C1-C3) are strongly correlated among them and weakly with primary (toluene) and secondary (ozone plus nitrogen dioxide or PAN) pollutants. In particular, the correlation between acetaldehyde and propanal values remains even if diurnal and nocturnal data are considered separately, indicating similar sources. All these aldehydes present maxima values in the morning (9-12h) and minima at night (0-3h). The best correlation is observed when butanal and 2-butenal data are considered (r=0.99, butanal/2-butenal=6.2). These compounds present maxima values during the 3-6h period, with minima values in the 0-3h period. These data imply a strong pre-dawn emission. Other aldehydes show different daily profiles, suggesting unrelated origins. Formaldehyde is the aldehyde whose concentration values best correlate with the levels of oxidants. The contribution of primary emissions and photochemical processes to formaldehyde concentrations were estimated by using a multiple regression. This treatment indicates that (32+/-16)% of measured values arise from direct emissions, while (79+/-23)% is attributable to secondary formation.

  8. A retention index calculator simplifies identification of plant volatile organic compounds

    USDA-ARS?s Scientific Manuscript database

    Plant volatiles (PVOCs) are important targets for studies in natural products, chemotaxonomy and biochemical ecology. The complexity of PVOC profiles often limits research to studies targeting only easily identified compounds. With the availability of mass spectral libraries and recent growth of ret...

  9. Microbial Volatile Organic Compound Emissions from Stachybotrys chartarum growing on Gypsum Wallboard and Ceiling tile

    EPA Science Inventory

    This study compared seven toxigenic strains of S. chartarum found in water-damaged buildings to characterize the microbial volatile organic compound (MVOC) emissions profile while growing on gypsum wallboard (W) and ceiling tile (C) coupons. The inoculated coupons with their sub...

  10. Microbial Volatile Organic Compound Emissions from Stachybotrys chartarum growing on Gypsum Wallboard and Ceiling tile

    EPA Science Inventory

    This study compared seven toxigenic strains of S. chartarum found in water-damaged buildings to characterize the microbial volatile organic compound (MVOC) emissions profile while growing on gypsum wallboard (W) and ceiling tile (C) coupons. The inoculated coupons with their sub...

  11. Comparative study on volatile compounds from Tunisian and Sicilian monovarietal virgin olive oils.

    PubMed

    Baccouri, Olfa; Bendini, Alessandra; Cerretani, Lorenzo; Guerfel, Mokhtar; Baccouri, Béchir; Lercker, Giovanni; Zarrouk, Mokhtar; Daoud Ben Miled, Douja

    2008-11-15

    The effects of ripening degree of olives on volatile profile of monovarietal virgin olive oils (VOO) from Tunisian and Sicilian cultivars were investigated. Fruits obtained from Tunisia (Chétoui and Chemlali) and Italy (Nocellara del Belice, Biancolilla and Cerasuola) were picked at three different stages of ripeness and then immediately processed. Moreover, the changes in volatile composition were evaluated in Chétoui variety as a function of the irrigation regime versus the rain-fed control. Using headspace-solid-phase microextraction (HS-SPME) technique coupled to GC-MS and GC-FID, the volatile compounds of the monovarietal virgin olive oils were identified and quantitatively analyzed. The proportions of different classes of volatiles of oils showed significant differences throughout the maturity process. The results suggest that adding to the genetic factor; agronomic conditions affect the volatile formation and therefore the organoleptic properties of VOO.

  12. Geographical traceability of Italian white truffle (Tuber magnatum Pico) by the analysis of volatile organic compounds.

    PubMed

    Gioacchini, Anna Maria; Menotta, Michele; Guescini, Michele; Saltarelli, Roberta; Ceccaroli, Paola; Amicucci, Antonella; Barbieri, Elena; Giomaro, Giovanna; Stocchi, Vilberto

    2008-10-01

    Results are presented that were obtained on the geographic traceability of the white truffle Tuber magnatum Pico. Solid-phase microextraction coupled to gas chromatography/mass spectrometry (SPME-GC/MS) was employed to characterize the volatile profile of T. magnatum white truffle produced in seven geographical areas of Italy. The main components of the volatile fraction were identified using SPME-GC/MS. Significant differences in the proportion of volatile constituents from truffles of different geographical areas were detected. The results suggest that, besides genetic factors, environmental conditions influence the formation of volatile organic compounds. The mass spectra of the volatile fraction of the samples were used as fingerprints to characterize the geographical origin. Next, stepwise factorial discriminant analysis afforded a limited number of characteristic fragment ions that allowed a geographical classification of the truffles studied.

  13. Characterization of the volatile profiles of beer using headspace solid-phase microextraction and gas chromatography-mass spectrometry.

    PubMed

    Rossi, Serena; Sileoni, Valeria; Perretti, Giuseppe; Marconi, Ombretta

    2014-03-30

    The objective of this study was a multivariate characterization of the volatile profile of beers. Such a characterization is timely considering the increasing worldwide consumption of beer, the continuous growth of microbreweries and the importance of volatile compounds to beer flavour. A method employing solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) was optimized and then applied to a sample set of 36 industrial and craft beers of various styles and fermentation types. The volatile profiles of different beer styles is described, with particular attention paid to the volatile compounds characteristic of a spontaneously fermented lambic raspberry framboise beer. Furthermore, it was also possible to identify which specific volatile compounds are principally responsible for the differences in the volatile profiles of top- and bottom-fermented beers. Moreover, a volatile fingerprint of the craft top-fermented Italian beers was defined, as they show a very similar volatile profile. Finally, the volatile compounds that are characteristic of the bock-style beers are described. The SPME-GC-MS analytical method optimized in this study is suitable for characterizing the volatile fingerprint of different beers, especially on the basis of the kind of fermentation (top, bottom or spontaneous), the method of production and the style of the beer. © 2013 Society of Chemical Industry.

  14. Speciation of volatile organic compounds from poultry production

    USDA-ARS?s Scientific Manuscript database

    The air consent agreement between EPA and large animal feeding operations (AFO) is designed to determine at what level compounds are being emitted from these facilities. However, the methodology used for quantifying total non-methane hydrocarbons and speciation of volatile organic compounds (VOC) n...

  15. VOLATILE ORGANIC COMPOUNDS MEASURED IN DEARS PASSIVE SAMPLERS

    EPA Science Inventory

    A suite of 27 volatile organic compounds (VOCs) were monitored in personal exposures, indoors and outdoors of participant's residences, and at a central community site during the DEARS summer 2004 monitoring season. The list of VOCs focused on compounds typically associated with ...

  16. VOLATILE ORGANIC COMPOUNDS MEASURED IN DEARS PASSIVE SAMPLERS

    EPA Science Inventory

    A suite of 27 volatile organic compounds (VOCs) were monitored in personal exposures, indoors and outdoors of participant's residences, and at a central community site during the DEARS summer 2004 monitoring season. The list of VOCs focused on compounds typically associated with ...

  17. Predicting the emission of volatile organic compounds from silage systems

    USDA-ARS?s Scientific Manuscript database

    As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major VOC emission source from farms is silage, with emissions coming from the silo face, mixing wagon, and feed bunk. The major compounds emitted are alcohols wit...

  18. Quantifying commuter exposures to volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Kayne, Ashleigh

    Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the

  19. Production of Volatile and Sulfur Compounds by 10 Saccharomyces cerevisiae Strains Inoculated in Trebbiano Must

    PubMed Central

    Patrignani, Francesca; Chinnici, Fabio; Serrazanetti, Diana I.; Vernocchi, Pamela; Ndagijimana, Maurice; Riponi, Claudio; Lanciotti, Rosalba

    2016-01-01

    In wines, the presence of sulfur compounds is the resulting of several contributions among which yeast metabolism. The characterization of the starter Saccharomyces cerevisiae needs to be performed also taking into account this ability even if evaluated together with the overall metabolic profile. In this perspective, principal aim of this experimental research was the evaluation of the volatile profiles, throughout GC/MS technique coupled with solid phase micro extraction, of wines obtained throughout the fermentation of 10 strains of S. cerevisiae. In addition, the production of sulfur compounds was further evaluated by using a gas-chromatograph coupled with a Flame Photometric Detector. Specifically, the 10 strains were inoculated in Trebbiano musts and the fermentations were monitored for 19 days. In the produced wines, volatile and sulfur compounds as well as amino acid concentrations were investigated. Also the physico-chemical characteristics of the wines and their electronic nose profiles were evaluated. PMID:26973621

  20. Biogenic volatile organic compound emissions from vegetation fires.

    PubMed

    Ciccioli, Paolo; Centritto, Mauro; Loreto, Francesco

    2014-08-01

    The aim of this paper was to provide an overview of the current state of the art on research into the emission of biogenic volatile organic compounds (BVOCs) from vegetation fires. Significant amounts of VOCs are emitted from vegetation fires, including several reactive compounds, the majority belonging to the isoprenoid family, which rapidly disappear in the plume to yield pollutants such as secondary organic aerosol and ozone. This makes determination of fire-induced BVOC emission difficult, particularly in areas where the ratio between VOCs and anthropogenic NOx is favourable to the production of ozone, such as Mediterranean areas and highly anthropic temperate (and fire-prone) regions of the Earth. Fire emissions affecting relatively pristine areas, such as the Amazon and the African savannah, are representative of emissions of undisturbed plant communities. We also examined expected BVOC emissions at different stages of fire development and combustion, from drying to flaming, and from heatwaves coming into contact with unburned vegetation at the edge of fires. We conclude that forest fires may dramatically change emission factors and the profile of emitted BVOCs, thereby influencing the chemistry and physics of the atmosphere, the physiology of plants and the evolution of plant communities within the ecosystem. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

  1. Biogenic volatile organic compound emissions from vegetation fires

    PubMed Central

    CICCIOLI, PAOLO; CENTRITTO, MAURO; LORETO, FRANCESCO

    2014-01-01

    The aim of this paper was to provide an overview of the current state of the art on research into the emission of biogenic volatile organic compounds (BVOCs) from vegetation fires. Significant amounts of VOCs are emitted from vegetation fires, including several reactive compounds, the majority belonging to the isoprenoid family, which rapidly disappear in the plume to yield pollutants such as secondary organic aerosol and ozone. This makes determination of fire-induced BVOC emission difficult, particularly in areas where the ratio between VOCs and anthropogenic NOx is favourable to the production of ozone, such as Mediterranean areas and highly anthropic temperate (and fire-prone) regions of the Earth. Fire emissions affecting relatively pristine areas, such as the Amazon and the African savannah, are representative of emissions of undisturbed plant communities. We also examined expected BVOC emissions at different stages of fire development and combustion, from drying to flaming, and from heatwaves coming into contact with unburned vegetation at the edge of fires. We conclude that forest fires may dramatically change emission factors and the profile of emitted BVOCs, thereby influencing the chemistry and physics of the atmosphere, the physiology of plants and the evolution of plant communities within the ecosystem. PMID:24689733

  2. Emission characteristics of volatile organic compounds from semiconductor manufacturing.

    PubMed

    Chein, HungMin; Chen, Tzu Ming

    2003-08-01

    A huge amount of volatile organic compounds (VOCs) is produced and emitted with waste gases from semiconductor manufacturing processes, such as cleaning, etching, and developing. VOC emissions from semiconductor factories located at Science-Based Industrial Park, Hsin-chu, Taiwan, were measured and characterized in this study. A total of nine typical semiconductor fabricators (fabs) were monitored over a 12-month period (October 2000-September 2001). A flame ionization analyzer was employed to measure the VOC emission rate continuously in a real-time fashion. The amount of chemical use was adopted from the data that were reported to the Environmental Protection Bureau in Hsin-chu County as per the regulation of the Taiwan Environmental Protection Administration. The VOC emission factor, defined as the emission rate (kg/month) divided by the amount of chemical use (L/month), was determined to be 0.038 +/- 0.016 kg/L. A linear regression equation is proposed to fit the data with the correlation coefficient (R2)=0.863. The emission profiles of VOCs, which were drawn using the gas chromatograph/mass spectrometer analysis method, show that isopropyl alcohol is the dominant compound in most of the fabs.

  3. Screening for emphysema via exhaled volatile organic compounds.

    PubMed

    Cristescu, S M; Gietema, H A; Blanchet, L; Kruitwagen, C L J J; Munnik, P; van Klaveren, R J; Lammers, J W J; Buydens, L; Harren, F J M; Zanen, P

    2011-12-01

    Chronic obstructive pulmonary disease (COPD)/emphysema risk groups are well defined and screening allows for early identification of disease. The capability of exhaled volatile organic compounds (VOCs) to detect emphysema, as found by computed tomography (CT) in current and former heavy smokers participating in a lung cancer screening trial, was investigated. CT scans, pulmonary function tests and breath sample collections were obtained from 204 subjects. Breath samples were analyzed with a proton-transfer reaction mass spectrometer (PTR-MS) to obtain VOC profiles listed as ions at various mass-to-charge ratios (m/z). Using bootstrapped stepwise forward logistic regression, we identified specific breath profiles as a potential tool for the diagnosis of emphysema, of airflow limitation or gas-exchange impairment. A marker for emphysema was found at m/z 87 (tentatively attributed to 2-methylbutanal). The area under the receiver operating characteristic curve (ROC) of this marker to diagnose emphysema was 0.588 (95% CI 0.453-0.662). Mass-to-charge ratios m/z 52 (most likely chloramine) and m/z 135 (alkyl benzene) were linked to obstructive disease and m/z 122 (most probably alkyl homologs) to an impaired diffusion capacity. ROC areas were 0.646 (95% CI 0.562-0.730) and 0.671 (95% CI 0.524-0.710), respectively. In the screening setting, exhaled VOCs measured by PTR-MS constitute weak markers for emphysema, pulmonary obstruction and impaired diffusion capacity.

  4. Monitoring single coffee bean roasting by direct volatile compound analysis with proton transfer reaction time-of-flight mass spectrometry.

    PubMed

    Yener, Sine; Navarini, Luciano; Lonzarich, Valentina; Cappellin, Luca; Märk, Tilmann D; Bonn, Günther K; Biasioli, Franco

    2016-09-01

    This study applies proton transfer reaction time-of-flight mass spectrometry for the rapid analysis of volatile compounds released from single coffee beans. The headspace volatile profiles of single coffee beans (Coffeea arabica) from different geographical origins (Brazil, Guatemala and Ethiopia) were analyzed via offline profiling at different stages of roasting. The effect of coffee geographical origin was reflected on volatile compound formation that was supported by one-way ANOVA. Clear origin signatures were observed in the formation of different coffee odorants. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Key volatile organic compounds emitted from swine nursery house

    NASA Astrophysics Data System (ADS)

    Yao, H. Q.; Choi, H. L.; Zhu, K.; Lee, J. H.

    2011-05-01

    This study was carried out to quantify the concentration and emission levels of key volatile organic compounds (VOCs) - sulfides, indolics, phenolics and volatile fatty acids (VFA) - emitted from swine nursery house, and assess the effect of microclimate (including temperature, relative humidity and air speed) on the key odorous compounds. Samples were collected from the Experimental Farm of Seoul National University in Suwon, South Korea. And the collection took place for four seasons and the sampling time was fixed at 10:30 in the morning. The application of one-way ANOVA and Bonferroni t analyses revealed that, most of the odorous compound concentrations, such as dimethyl sulfide (DMS), dimethyl disulfide (DMDS), indole, p-cresol and all the volatile fatty acids were lowest during the summer ( P < 0.01). Meanwhile, negative correlations were observed between temperature and odorants, as well as air speed and odorants. A possible reason was that high ventilation transferred most of the odors out of the house during the summer. From the whole year data, non-linear multiple regressions were conducted and the equations were proposed depending upon the relationships between microclimate parameters and odorous compounds. The equations were applied in hope of easily calculating the concentrations of the odorous compounds in the commercial farms. The results obtained in this study should be used for reducing the volatile organic compounds by controlling microclimate parameters and also could be helpful in setting a guideline for good management practices in nursery house.

  6. Impact of frozen storage time on the volatile profile of wheat bread crumb.

    PubMed

    Pico, Joana; Martínez, Mario M; Bernal, José; Gómez, Manuel

    2017-10-01

    The freezing of wheat bread before aroma analyses is a common practice in order to preserve loss of the volatile profile. However, the impact of the frozen storage time on the aroma profile has not been studied. For this purpose, the volatile profiles of wheat bread frozen for 1, 2 and 4weeks were analysed employing solvent extraction and static headspace methoologies with GC/MS. The results revealed that the freezing was effective to prevent the loss of volatiles during the first week. However, after two weeks, there was an increase of volatile compounds, probably generated by chemical reactions. Thus, a maximum of one week of frozen storage was recommended when using the solvent extraction methodology. When using the static headspace method, the samples should be analysed on the same day as preparation, since the extraction was surprisingly increased due to the starch retrogradation that occurred during freezing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Ripening-dependent metabolic changes in the volatiles of pineapple (Ananas comosus (L.) Merr.) fruit: II. Multivariate statistical profiling of pineapple aroma compounds based on comprehensive two-dimensional gas chromatography-mass spectrometry.

    PubMed

    Steingass, Christof Björn; Jutzi, Manfred; Müller, Jenny; Carle, Reinhold; Schmarr, Hans-Georg

    2015-03-01

    Ripening-dependent changes of pineapple volatiles were studied in a nontargeted profiling analysis. Volatiles were isolated via headspace solid phase microextraction and analyzed by comprehensive 2D gas chromatography and mass spectrometry (HS-SPME-GC×GC-qMS). Profile patterns presented in the contour plots were evaluated applying image processing techniques and subsequent multivariate statistical data analysis. Statistical methods comprised unsupervised hierarchical cluster analysis (HCA) and principal component analysis (PCA) to classify the samples. Supervised partial least squares discriminant analysis (PLS-DA) and partial least squares (PLS) regression were applied to discriminate different ripening stages and describe the development of volatiles during postharvest storage, respectively. Hereby, substantial chemical markers allowing for class separation were revealed. The workflow permitted the rapid distinction between premature green-ripe pineapples and postharvest-ripened sea-freighted fruits. Volatile profiles of fully ripe air-freighted pineapples were similar to those of green-ripe fruits postharvest ripened for 6 days after simulated sea freight export, after PCA with only two principal components. However, PCA considering also the third principal component allowed differentiation between air-freighted fruits and the four progressing postharvest maturity stages of sea-freighted pineapples.

  8. Optimizing headspace temperature and time sampling for identification of volatile compounds in ground roasted Arabica coffee.

    PubMed

    Sanz, C; Ansorena, D; Bello, J; Cid, C

    2001-03-01

    Equilibration time and temperature were the factors studied to choose the best conditions for analyzing volatiles in roasted ground Arabica coffee by a static headspace sampling extraction method. Three temperatures of equilibration were studied: 60, 80, and 90 degrees C. A larger quantity of volatile compounds was extracted at 90 degrees C than at 80 or 60 degrees C, although the same qualitative profile was found for each. The extraction of the volatile compounds was studied at seven different equilibration times: 30, 45, 60, 80, 100, 120, and 150 min. The best time of equilibration for headspace analysis of roasted ground Arabica coffee should be selected depending on the chemical class or compound studied. One hundred and twenty-two volatile compounds were identified, including 26 furans, 20 ketones, 20 pyrazines, 9 alcohols, 9 aldehydes, 8 esters, 6 pyrroles, 6 thiophenes, 4 sulfur compounds, 3 benzenic compounds, 2 phenolic compounds, 2 pyridines, 2 thiazoles, 1 oxazole, 1 lactone, 1 alkane, 1 alkene, and 1 acid.

  9. Effect of fermentation time and drying temperature on volatile compounds in cocoa.

    PubMed

    Rodriguez-Campos, J; Escalona-Buendía, H B; Contreras-Ramos, S M; Orozco-Avila, I; Jaramillo-Flores, E; Lugo-Cervantes, E

    2012-05-01

    The effects of fermentation time and drying temperature on the profile of volatile compounds were evaluated after 2, 4, 6, and 8 fermentation days followed by drying at 60, 70 and 80°C. These treatments were compared with dry cocoa controls produced in a Samoa drier and by a sun-drying process. A total of 58 volatile compounds were identified by SPME-HS/GC-MS and classified as: esters (20), alcohols (12), acids (11), aldehydes and ketones (8), pyrazines (4) and other compounds (3). Six days of fermentation were enough to produce volatile compounds with flavour notes desirable in cocoa beans, as well as to avoid the production of compounds with off-flavour notes. Drying at 70 and 80°C after six fermentation days presented a volatile profile similar to the one obtained by sun drying. However, drying at 70°C represents a lower cost. Given the above results, in the present study the optimal conditions for fermentation and drying of cocoa beans were 6days of fermentation, followed by drying at 70°C.

  10. Urinary Volatile Organic Compounds for the Detection of Prostate Cancer

    PubMed Central

    Khalid, Tanzeela; Aggio, Raphael; White, Paul; De Lacy Costello, Ben; Persad, Raj; Al-Kateb, Huda; Jones, Peter; Probert, Chris S.; Ratcliffe, Norman

    2015-01-01

    The aim of this work was to investigate volatile organic compounds (VOCs) emanating from urine samples to determine whether they can be used to classify samples into those from prostate cancer and non-cancer groups. Participants were men referred for a trans-rectal ultrasound-guided prostate biopsy because of an elevated prostate specific antigen (PSA) level or abnormal findings on digital rectal examination. Urine samples were collected from patients with prostate cancer (n = 59) and cancer-free controls (n = 43), on the day of their biopsy, prior to their procedure. VOCs from the headspace of basified urine samples were extracted using solid-phase micro-extraction and analysed by gas chromatography/mass spectrometry. Classifiers were developed using Random Forest (RF) and Linear Discriminant Analysis (LDA) classification techniques. PSA alone had an accuracy of 62–64% in these samples. A model based on 4 VOCs, 2,6-dimethyl-7-octen-2-ol, pentanal, 3-octanone, and 2-octanone, was marginally more accurate 63–65%. When combined, PSA level and these four VOCs had mean accuracies of 74% and 65%, using RF and LDA, respectively. With repeated double cross-validation, the mean accuracies fell to 71% and 65%, using RF and LDA, respectively. Results from VOC profiling of urine headspace are encouraging and suggest that there are other metabolomic avenues worth exploring which could help improve the stratification of men at risk of prostate cancer. This study also adds to our knowledge on the profile of compounds found in basified urine, from controls and cancer patients, which is useful information for future studies comparing the urine from patients with other disease states. PMID:26599280

  11. Geographical variation in the exhaled volatile organic compounds.

    PubMed

    Amal, Haitham; Leja, Marcis; Broza, Yoav Y; Tisch, Ulrike; Funka, Konrads; Liepniece-Karele, Inta; Skapars, Roberts; Xu, Zhen-Qin; Liu, Hu; Haick, Hossam

    2013-12-01

    Breath-gas analysis has demonstrated that concentration profiles of volatile organic compounds (VOCs) could be used for detecting a variety of diseases, among them gastric cancer (GC) and peptic ulcer disease (PUD). Here, we explore how geographical variation affects the disease-specific changes in the chemical composition of breath samples, as compared to control states (less severe gastric conditions). Alveolar exhaled breath samples from 260 patients were collected at two remotely different geographic locations (China and Latvia), following similar breath-collection protocols. Each cohort included 130 patients that were matched in terms of diagnosis (37 GC/32 PUD/61 controls), average age, gender ratio and smoking habits. Helicobacter Pylori infection, which is a major cause for GC and PUD, was found in part of the patients, as well as in part of the controls, at both locations. The breath samples were analyzed by gas chromatography/mass spectrometry, using the same equipment and protocol-of-experiment. We observed similar characteristic differences in the chemical composition of the breath samples between the study groups at the two locations, even though the exact composition of the breath samples differed. Both in China and Latvia, the GC patients and controls could be distinguished by differences in the average levels of 6-methyl-5-hepten-2-one; PUD patients were distinguished from controls by the levels of aromatic compounds and alcohols; GC and PUD patients could not be distinguished at either site. This pilot study indicates the limitations of chemical breath-gas analysis alone for identifying gastric diseases based on the concentration profiles of separate VOCs in international patient cohorts. We assume that these limitations would apply to other diseases as well. The presented data could potentially be useful for developing an alternative, universally applicable diagnostic method that relies on the detection of changes in the collective patterns of

  12. Relationships between volatile compounds and sensory characteristics in virgin olive oil by analytical and chemometric approaches.

    PubMed

    Procida, Giuseppe; Cichelli, Angelo; Lagazio, Corrado; Conte, Lanfranco S

    2016-01-15

    The volatile fraction of virgin olive oil is characterised by low molecular weight compounds that vaporise at room temperature. In order to obtain an aroma profile similar to natural olfactory perception, the composition of the volatile compounds was determined by applying dynamic headspace gas chromatography, performed at room temperature, with a cryogenic trap directly connected to a gas chromatograph-mass spectrometer system. Samples were also evaluated according to European Union and International Olive Council official methods for sensory evaluation. In this paper, the composition of the volatile fraction of 25 extra virgin olive oils from different regions of Italy was analysed and some preliminary considerations on relationships between chemical composition of volatile fraction and sensory characteristics are reported. Forty-two compounds were identified by means of the particular analytical technique used. All the analysed samples, classified as extra virgin by the panel test, never present peaks whose magnitude is important enough in defected oils. The study was focused on the evaluation of volatile compounds responsible for the positive impact on olive odour properties ('green-fruity' and 'sweet') and olfactory perception. Chemometric evaluation of data, obtained through headspace analysis and the panel test evaluation, showed a correlation between chemical compounds and sensory properties. On the basis of the results, the positive attributes of virgin olive oil are divided into two separated groups: sweet types or green types. Sixteen volatile compounds with known positive impact on odour properties were extracted and identified. In particular, eight compounds seem correlated with sweet properties whereas the green sensation appears to be correlated with eight other different substances. The content of the compounds at six carbon atoms proves to be very important in defining positive attributes of extra virgin olive oils and sensory evaluation. © 2015

  13. Study of volatile compounds from the radiosterilization of solid cephalosporins

    NASA Astrophysics Data System (ADS)

    Barbarin, N.; Crucq, A. S.; Tilquin, B.

    1996-12-01

    The use of γ-rays is a promising method to sterilize thermosensitive drugs. Although radiosterilization does not modify drugs activity, this mode of sterilization produces new radiolytic products. This study is devoted to the analysis of volatile compounds which may induce a modification of odour. The volatile compounds produced by radiolysis of cefotaxime, cefuroxime and ceftazidime, three cephalosporins, were analyzed by gas chromatography with headspace sampling. They were detected and identified by mass and infrared spectrometry. An explanation of their origin is proposed.

  14. Spatial distribution of volatile compounds in graphite composites

    NASA Technical Reports Server (NTRS)

    Grayson, M. A.; Wolf, C. J.; Kourtides, D. A.

    1980-01-01

    The distribution of water and other volatile compounds such as acetone and phenol was measured as a function of depth in four graphite resin matrix composites. Precision abrasion mass spectrometry was used to qualitatively and quantitatively characterize the indigenous volatile compounds in the as received condition and after drying in an environmentally controlled oven. The total amount of water in the composites varied from 0.12 wt% to 1.1 wt% and the times required to dry the samples ranged from less than 96 h to much greater than 555 h.

  15. [Volatile Organic Compounds (VOC): definition, classification and properties].

    PubMed

    Cicolella, A

    2008-02-01

    The term volatile organic compounds includes a wide variety of chemical substances with the common feature of being carbon compounds that are volatile at ambient temperature. They can be classified into different families defined by their chemical formulae, each of which possesses common properties, although there may be major differences in terms of toxicity. For that reason the effects of VOC on health have to be considered both in an individual way and also from a global viewpoint on account of their common toxic properties and the role they play in the formation of environmental photo-oxidative pollutants, both outdoors and indoors.

  16. Exposure to volatile organic compounds in healthcare settings

    PubMed Central

    LeBouf, Ryan F; Virji, M Abbas; Saito, Rena; Henneberger, Paul K; Simcox, Nancy; Stefaniak, Aleksandr B

    2015-01-01

    Objectives To identify and summarise volatile organic compound (VOC) exposure profiles of healthcare occupations. Methods Personal (n=143) and mobile area (n=207) evacuated canisters were collected and analysed by a gas chromatograph/mass spectrometer to assess exposures to 14 VOCs among 14 healthcare occupations in five hospitals. Participants were volunteers identified by their supervisors. Summary statistics were calculated by occupation. Principal component analysis (PCA) was used to reduce the 14 analyte inputs to five orthogonal factors and identify occupations that were associated with these factors. Linear regressions were used to assess the association between personal and mobile area samples. Results Exposure profiles differed among occupations; ethanol had the highest geometric mean (GM) among nursing assistants (~4900 and ~1900 μg/m3, personal and area), and 2-propanol had the highest GM among medical equipment preparers (~4600 and ~2000 μg/m3, personal and area). The highest total personal VOC exposures were among nursing assistants (~9200 μg/m3), licensed practical nurses (~8700 μg/m3) and medical equipment preparers (~7900 μg/m3). The influence of the PCA factors developed from personal exposure estimates varied by occupation, which enabled a comparative assessment of occupations. For example, factor 1, indicative of solvent use, was positively correlated with clinical laboratory and floor stripping/waxing occupations and tasks. Overall, a significant correlation was observed (r=0.88) between matched personal and mobile area samples, but varied considerably by analyte (r=0.23–0.64). Conclusions Healthcare workers are exposed to a variety of chemicals that vary with the activities and products used during activities. These VOC profiles are useful for estimating exposures for occupational hazard ranking for industrial hygienists as well as epidemiological studies. PMID:25011549

  17. Impact of high hydrostatic pressure on non-volatile and volatile compounds of squid muscles.

    PubMed

    Yue, Jin; Zhang, Yifeng; Jin, Yafang; Deng, Yun; Zhao, Yanyun

    2016-03-01

    The effects of high hydrostatic pressure processing (HHP at 200, 400 or 600MPa) on non-volatile and volatile compounds of squid muscles during 10-day storage at 4°C were investigated. HHP increased the concentrations of Cl(-) and volatile compounds, reduced the level of PO4(3-), but did not affect the contents of 5'-uridine monophosphate (UMP), 5'-guanosine monophosphate (GMP), 5'-inosine monophosphate (IMP), Na(+) and Ca(2+) in squids on Day 0. At 600MPa, squids had the highest levels of 5'-adenosine monophosphate, Cl(-) and lactic acid, but the lowest contents of CMP and volatile compounds on Day 10. Essential free amino acids and succinic acids were lower on Day 0 than on Day 10. HHP at 200MPa caused higher equivalent umami concentration (EUC) on Day 0, and the EUC decreased with increasing pressure on Day 10. Generally, HHP at 200MPa was beneficial for improving EUC and volatile compounds of squids. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Dynamic headspace gas chromatography of volatile compounds in milk.

    PubMed

    Urbach, G

    1987-08-28

    A method is described for investigating volatile compounds in milk. The volatiles are removed from milk by a stream of helium swept at 100 ml/min over the surface of the milk at 70 degrees C. They are trapped on 40 mg of NIOSH charcoal and then desorbed by heat and re-trapped on the front of a chromatographic column of Tenax-GC coated with 1% OV-275, the column being maintained at room temperature during trapping. An amount of 40 mg NIOSH charcoal under these conditions traps over 90% of the total quantity of the lowest boiling compounds swept from the milk, such as acetaldehyde and ethanol, and retains 100% of the total quantity of acetone, propanol and higher boiling compounds from the gas stream. The volume of milk and its temperature affect the ratios of volatiles collected and these factors are useful in increasing the proportion of a volatile of particular interest. The addition of potassium carbonate increases the yield of volatiles from 100 ml aqueous phase but not from 10 ml.

  19. Aroma Volatile Compounds from Two Fresh Pineapple Varieties in China

    PubMed Central

    Zheng, Liang-Yong; Sun, Guang-Ming; Liu, Yu-Ge; Lv, Ling-Ling; Yang, Wen-Xiu; Zhao, Wei-Feng; Wei, Chang-Bin

    2012-01-01

    Volatile compounds from two pineapples varieties (Tainong No.4 and No.6) were isolated by headspace solid phase microextraction (HS-SPME) and identified and quantified by gas chromatography-mass spectrometry (GC/MS). In the Tainong No. 4 and No. 6 pineapples, a total of 11 and 28 volatile compounds were identified according to their retention time on capillary columns and their mass spectra, and quantified with total concentrations of 1080.44 μg·kg−1 and 380.66 μg·kg−1 in the Tainong No.4 and No. 6 pineapples, respectively. The odor active values (OAVs) of volatile compounds from pineapples were also calculated. According to the OAVs, four compounds were defined as the characteristic aroma compounds for the Tainong No. 4 pineapple, including furaneol, 3-(methylthio)propanoic acid methyl ester, 3-(methylthio)propanoic acid ethyl ester and δ-octalactone. The OAVs of five compounds including ethyl-2-methylbutyrate, methyl-2-methylbutyrate, 3-(methylthio)propanoic acid ethyl ester, ethyl hexanoate and decanal were considered to be the characteristic aroma compounds for the Tainong No. 6 pineapple. PMID:22837701

  20. Effect of aging on volatile compounds in cooked beef.

    PubMed

    Watanabe, A; Kamada, G; Imanari, M; Shiba, N; Yonai, M; Muramoto, T

    2015-09-01

    Volatiles in the headspace of beef cooked at 180 °C were analyzed using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS), and the effects of aging were evaluated. Seventy volatile substances including non-aromatic, homocyclic, and heterocyclic compounds were identified. A significant positive regression model for storage could be adopted for toluene, benzeneacetaldehyde, 2-formylfuran, pyrazine, 2,6-dimethylpyrazine, 2,3-dimethylpyrazine, 2-acetylthiazole, and 2-formyl-3-methylthiophene. Increases in the quantity of these compounds, with the exception of toluene, suggest the importance of the Strecker and Maillard reactions in cooked meat previously aged under vacuum conditions. As such, the aging process may lead to an increase not only in the amount of compounds related to the taste of meat, but also in the quantity of odor-active compounds. The increased quantity of toluene during storage seemed to be influenced by lipid oxidation.

  1. Source identification of volatile organic compounds in Houston, Texas.

    PubMed

    Zhao, Weixiang; Hopke, Philip K; Karl, Thomas

    2004-03-01

    The complexity of the volatile organic compound (VOC) mixture in the Houston area makes studies of the air quality in that area very challenging. In this paper, a novel factor analysis model, where the normal chemical mass balance model was augmented by a parallel equation that accounted for wind speed and direction, temperature, and weekend/weekday effects, was fitted with a multilinear engine (ME) to provide identification and apportionment of the VOC sources at the La Porte Municipal Airport site in Houston during the Texas Air Quality Study (TexAQS) 2000. The analysis determined the profiles and contributions of nine sources and the corresponding wind speed, wind direction, temperature, and weekend factors. The reasonableness of these results not only suggests the high resolving power of the expanded factor analysis model for source apportionment but also provides the novel and effective auxiliary information for more specific source identification. In addition, a new approach to estimate the measurement uncertainty and the details of determining the source number and dealing with missing values are also presented as important parts of the data analysis process. This study demonstrates the feasibility of the expanded model to identify sources in complex VOC systems and extract useful information for locating VOC emitters and controlling their emissions in the Houston area.

  2. Measurements of volatile organic compounds over West Africa

    NASA Astrophysics Data System (ADS)

    Murphy, J. G.; Oram, D. E.; Reeves, C. E.

    2010-06-01

    In this paper we describe measurements of volatile organic compounds (VOC) made using a Proton Transfer Reaction Mass Spectrometer (PTR-MS) aboard the UK Facility for Atmospheric Airborne Measurements during the African Monsoon Multidisciplinary Analyses (AMMA) campaign. Observations were made during approximately 85 h of flying time between 17 July and 17 August 2006, above an area between 4° N and 18° N and 3° W and 4° E, encompassing ocean, mosaic forest, and the Sahel desert. High time resolution observations of counts at mass to charge (m/z) ratios of 42, 59, 69, 71, and 79 were used to calculate mixing ratios of acetonitrile, acetone, isoprene, the sum of methyl vinyl ketone and methacrolein, and benzene respectively using laboratory-derived humidity-dependent calibration factors. Strong spatial associations between vegetation and isoprene and its oxidation products were observed in the boundary layer, consistent with biogenic emissions followed by rapid atmospheric oxidation. Acetonitrile, benzene, and acetone were all enhanced in airmasses which had been heavily influenced by biomass burning. Benzene and acetone were also elevated in airmasses with urban influence from cities such as Lagos, Cotonou, and Niamey. The observations provide evidence that both deep convection and mixing associated with fair-weather cumulus were responsible for vertical redistribution of VOC emitted from the surface. Profiles over the ocean showed a depletion of acetone in the marine boundary layer, but no significant decrease for acetonitrile.

  3. Measurements of volatile organic compounds over West Africa

    NASA Astrophysics Data System (ADS)

    Murphy, J. G.; Oram, D. E.; Reeves, C. E.

    2010-02-01

    In this paper we describe measurements of volatile organic compounds (VOCs) made using a Proton Transfer Reaction Mass Spectrometer (PTR-MS) aboard the UK Facility for Atmospheric Airborne Measurements during the African Monsoon Multidisciplinary Analyses (AMMA) campaign. Observations were made during approximately 85 h of flying time between 17 July and 17 August 2006, above an area between 4° N and 18° N and 3° W and 4° E, encompassing ocean, mosaic forest, and the Sahel desert. High time resolution observations of counts at mass to charge (m/z) ratios of 42, 59, 69, 71, and 79 were used to calculate mixing ratios of acetonitrile, acetone, isoprene, the sum of methyl vinyl ketone and methacrolein, and benzene, respectively using laboratory-derived humidity-dependent calibration factors. Strong spatial associations between vegetation and isoprene and its oxidation products were observed in the boundary layer, consistent with biogenic emissions followed by rapid atmospheric oxidation. Acetonitrile, benzene, and acetone were all enhanced in airmasses which had been heavily influenced by biomass burning. Benzene and acetone were also elevated in airmasses with urban influence from cities such as Lagos, Cotonou, and Niamey. The observations provide evidence that both deep convection and mixing associated with fair-weather cumulus were responsible for vertical redistribution of VOCs emitted from the surface. Profiles over the ocean showed a depletion of acetone in the marine boundary layer, but no significant decrease for acetonitrile.

  4. Real time analysis of volatile organic compounds (VOCs) in centenarians.

    PubMed

    Mazzatenta, Andrea; Pokorski, Mieczyslaw; Di Giulio, Camillo

    2015-04-01

    Centenarians are a model to study human longevity and the physiological process of aging. A plethora of studies on this model show the complexity of the system. Laboratory studies fail to find a biomarker of senescence. The real time exhaled breath volatile organic compounds (VOCs) has been suggested as a new biomarker to detect and monitor physiological processes in the respiratory system. VOCs exhaled by centenarians have not been studied in the general population and across-age-groups. In the present study we investigated, in real time, the breath properties and VOC exhaled content in healthy centenarians as compared with non-centenarian seniors and young healthy subjects. We found distinctly different breath pattern and distribution profiles of VOCs in the centenarians. Thus, the VOCs measurement allowed to discriminate the differences between the age-groups. We propose a VOCs fingerprint as a biomarker underlying the physiological mechanisms of aging and longevity. Longevity should be considered physiologically as a new phase of life, characteristic of the well adapted subject. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Field screening of volatile organochlorine compounds using ion mobility spectrometry

    SciTech Connect

    Stach, J.; Brodacki, M.; Doering, H.R.; Flachowsky, J.

    1995-12-31

    Chlorinated alkanes and alkenes produce due to a dissociative charge transfer reaction strong signals of Cl{sup {minus}} ions in ion mobility spectra. This reaction can be used to analyze these compounds in on site analyses. The method is applicable to dump gases, soil air or soil using head space techniques and volatile halogen compounds dissolved in organic solvents. The results obtained by ion mobility spectrometry correlate with GC/MS or AOX measurements in most cases.

  6. Volatile organic compounds of whole grain soft winter wheat

    USDA-ARS?s Scientific Manuscript database

    The aroma from volatile organic compounds (VOCs) is an indicator of grain soundness and also an important quality attribute of grain foods. To identify the inherent VOCs of wheat grain unaffected by fungal infestation and other extrinsic factors, grains of nine soft wheat varieties were collected at...

  7. Novel collection method for volatile organic compounds (VOCs) from dogs

    USDA-ARS?s Scientific Manuscript database

    Host derived chemical cues are an important aspect of arthropod attraction to potential hosts. Host cues that act over longer distances include CO2, heat, and water vapor, while cues such as volatile organic compounds (VOCs) act over closer distances. Domestic dogs are important hosts for disease cy...

  8. MICROBIAL VOLATILE ORGANIC COMPOUND EMISSION RATES AND EXPOSURE MODEL

    EPA Science Inventory

    This paper presents the results from a study that examined microbial volatile organic compound (MVOC) emissions from six fungi and one bacterial species (Streptomyces spp.) commonly found in indoor environments. Data are presented on peak emission rates from inoculated agar plate...

  9. Volatile and semivolatile organic compounds in laboratory peat fire emissions

    EPA Science Inventory

    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 particula...

  10. Modeling emissions of volatile organic compounds from silage

    USDA-ARS?s Scientific Manuscript database

    Photochemical smog is a major air pollution problem and a significant cause of premature death in the U.S. Smog forms in the presence of volatile organic compounds (VOCs), which are emitted primarily from industry and motor vehicles in the U.S. However, dairy farms may be an important source in so...

  11. Volatile and semivolatile organic compounds in laboratory peat fire emissions

    EPA Science Inventory

    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 particula...

  12. Influence of volatile organic compounds on Fusarium graminearum mycotoxin production

    USDA-ARS?s Scientific Manuscript database

    Volatile organic compounds (VOCs) are involved in a diverse range of ecological interactions. Due to their low molecular weight, lipophilic nature, and high vapor pressure at ambient temperatures, they can serve as airborne signaling molecules that are capable of mediating inter and intraspecies com...

  13. LEAVES AS INDICATORS OF EXPOSURE TO AIRBORNE VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    The concentration of volatile organic compounds (VOCs) in leaves is primarily a product of airborne exposures and dependent upon bioconcentration factors and release rates. The bioconcentration factors for VOCs in grass are found to be related to their partitioning between octan...

  14. Qualitative analysis of volatile organic compounds on biochar

    USDA-ARS?s Scientific Manuscript database

    Qualitative identification of sorbed volatile organic compounds (VOCs) on biochar was conducted by headspace thermal desorption coupled to capillary gas chromatographic-mass spectrometry. VOCs may have a mechanistic role influencing plant and microbial responses to biochar amendments, since VOCs ca...

  15. LEAVES AS INDICATORS OF EXPOSURE TO AIRBORNE VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    The concentration of volatile organic compounds (VOCs) in leaves is primarily a product of airborne exposures and dependent upon bioconcentration factors and release rates. The bioconcentration factors for VOCs in grass are found to be related to their partitioning between octan...

  16. MICROBIAL VOLATILE ORGANIC COMPOUND EMISSION RATES AND EXPOSURE MODEL

    EPA Science Inventory

    This paper presents the results from a study that examined microbial volatile organic compound (MVOC) emissions from six fungi and one bacterial species (Streptomyces spp.) commonly found in indoor environments. Data are presented on peak emission rates from inoculated agar plate...

  17. Volatile organic compound emissions from dairy facilities in central California

    USDA-ARS?s Scientific Manuscript database

    Emissions of volatile organic compounds (VOCs) from dairy facilities are thought to be an important contributor to high ozone levels in central California, but emissions inventories from these sources contain significant uncertainties. In this work, VOC emissions were measured at two central Califor...

  18. Measuring Emissions of Volatile Organic Compounds from Silage

    USDA-ARS?s Scientific Manuscript database

    Volatile organic compound (VOC) emissions are considered to be important precursors to smog and ozone production. An experimental protocol was developed to obtain undisturbed silage samples from silage storages. Samples were placed in a wind tunnel where temperature, humidity, and air flow were cont...

  19. Modeling emissions of volatile organic compounds from silage

    USDA-ARS?s Scientific Manuscript database

    Volatile organic compounds (VOCs), necessary reactants for photochemical smog formation, are emitted from numerous sources. Limited available data suggest that dairy farms emit VOCs with cattle feed, primarily silage, being the primary source. Process-based models of VOC transfer within and from si...

  20. Composition, proteolysis, and volatile profile of Strachitunt cheese.

    PubMed

    Masotti, F; Cattaneo, S; Stuknytė, M; Battelli, G; Vallone, L; De Noni, I

    2017-03-01

    Strachitunt, a blue-veined Italian cheese, received the Protected Designation of Origin (PDO) label in 2014. Its unique technological feature is represented by the dual-curd method of production. Strachitunt is produced from raw bovine milk with or without the inoculation of natural starter cultures of lactic acid bacteria, and the addition of secondary cultures of mold spores is not permitted by the product specification. Physico-chemical properties, proteolysis, and volatile profile of Strachitunt were investigated in 10 cheese samples (ripened for 75 d) made throughout spring 2015 and provided by the main cheese maker. Overall, composition parameters showed a large variability among samples. Cheese was characterized by an acid paste (pH 5.46) and a lower extent of proteolysis compared with other blue-veined varieties. The main chemical groups of volatile organic compounds were alcohols and esters, whereas ketones represented only a minor component. The erratic adventitious contamination by mold spores of the cheese milk, the unique dual-curd method of cheese-making, and the large time variability between the piercing time and the end of ripening could be highlighted as the main causes of both the distinctive analytical fingerprint and the scarce standardization of this blue-veined cheese.

  1. Capillary gas chromatography-mass spectrometry of volatile and semi-volatile compounds of Salvia officinalis.

    PubMed

    Radulescu, Valeria; Chiliment, Silvia; Oprea, Eliza

    2004-02-20

    The essential oil and infusion of Salvia officinalis leaves have been widely applied in traditional medicine since ancient times and nowadays subjected to extensive research of their antibacterial, antiviral and cytotoxic properties. This paper shows chemical composition data of S. officinalis leaves essential oil isolated by steam distillation using a Clevenger-type apparatus. Also, the paper presents the chemical content of volatile and semi-volatile compounds of S. officinalis leaves infusion. The volatile and semi-volatile compounds of S. officinalis leaves infusion were isolated by solid-phase extraction (SPE) and liquid-liquid extraction with hexane and dichloromethane. SPE was carried out on 500 mg octadecylsilane (C18) cartridges and elution with dichloromethane. Liquid-liquid extraction was performed with hexane and dichloromethane. The essential oil in dichloromethane and infusion extracts in hexane and dichloromethane were analyzed by gas chromatography coupled with mass spectrometry. The quantitative results obtained by solid-phase extraction and liquid-liquid extraction showed that SPE on C18 performed the highest recovery of the volatile compounds from infusion sample.

  2. HS-GC/MS volatile profile of different varieties of garlic and their behavior under heating.

    PubMed

    Molina-Calle, María; Priego-Capote, Feliciano; de Castro, María D Luque

    2016-05-01

    Garlic is one of the most used seasonings in the world whose beneficial health effects, mainly ascribed to organosulfur compounds, are shared with the rest of the Allium family. The fact that many of these compounds are volatile makes the evaluation of the volatile profile of garlic interesting. For this purpose, three garlic varieties-White, Purple, and Chinese-cultivated in the South of Spain were analyzed by a method based on a headspace (HS) device coupled to a gas chromatograph and mass detector (HS-GC/MS). The main temperatures in the HS were optimized to achieve the highest concentration of volatiles. A total number of 45 volatiles were tentatively identified (among them 17 were identified for the first time in garlic); then, all were classified, also for the first time, and their relative concentration in three garlic varieties was used to evaluate differences among them and to study their profiles according to the heating time. Chinese garlic was found to be the richest variety in sulfur volatiles, while the three varieties presented a similar trend under preset heating times allowing differentiation between varieties and heating time using principal component analysis. Graphical Abstract HS-GC/MS analysis of the volatile profile of garlic.

  3. Flavor of roasted peanuts (Arachis hypogaea) - Part II: Correlation of volatile compounds to sensory characteristics.

    PubMed

    Lykomitros, Dimitrios; Fogliano, Vincenzo; Capuano, Edoardo

    2016-11-01

    Flavor and color of roasted peanuts are important research areas due to their significant influence on consumer preference. The aim of the present study was to explore correlations between sensory attributes of peanuts, volatile headspace compounds and color parameters. Different raw peanuts were selected to be representative of common market types, varieties, growing locations and grades used in Europe. Peanuts were roasted by a variety of processing technologies, resulting in 134 unique samples, which were analyzed for color, volatile composition and flavor profile by expert panel. Several headspace volatile compounds which positively or negatively correlated to "roasted peanut", "raw bean", "dark roast" and "sweet" attributes were identified. Results demonstrated that the correlation of CIELAB color parameters with roast related aromas, often taken for granted by the industry, is not strong when samples of different raw materials are subjected to different processing conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Effect of chitosan-lemon essential oil coatings on volatile profile of strawberries during storage.

    PubMed

    Perdones, Ángela; Escriche, Isabel; Chiralt, Amparo; Vargas, Maria

    2016-04-15

    Chitosan coatings containing lemon essential oils were described as effective at controlling fruit fungal decay at 20°C during 7 days. In this work, GC-MS was used to characterise the volatile compounds of strawberries during cold storage in order to analyse the influence of fruit coatings with chitosan, containing or not containing lemon essential oil, on the volatile profile of the fruits. The coatings affected the metabolic pathways and volatile profile of the fruits. Pure chitosan promoted the formation of esters and dimethyl furfural in very short time after coating, while coatings containing lemon essential oil incorporated terpenes (limonene, γ-terpinene, p-cymene and α-citral) to the fruit volatiles and enhanced the fermentative process, modifying the typical fruit aroma composition. No effect of chitosan coatings was sensorially perceived, the changes induced by lemon essential oil were notably appreciated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Transport of volatile organic compounds across the capillary fringe

    USGS Publications Warehouse

    McCarthy, Kathleen A.; Johnson, Richard L.

    1993-01-01

    Physical experiments were conducted to investigate the transport of a dissolved volatile organic compound (trichloroethylene, TCE) from shallow groundwater to the unsaturated zone under a variety of conditions including changes in the soil moisture profile and water table position. Experimental data indicated that at moderate groundwater velocities (0.1 m/d), vertical mechanical dispersion was negligible and molecular diffusion was the dominant vertical transport mechanism. Under these conditions, TCE concentrations decreased nearly 3 orders of magnitude across the capillary fringe and soil gas concentrations remained low relative to those of underlying groundwater. Data collected during a water table drop showed a short-term increase in concentrations throughout most of the unsaturated zone, but these concentrations quickly declined and approached initial values after the water table was returned to its original level. In the deep part of the unsaturated zone, the water table drop resulted in a long-term decrease in concentrations, illustrating the effects of hysteresis in the soil moisture profile. A two-dimensional random walk advection-diffusion model was developed to simulate the experimental conditions, and numerical simulations agreed well with experimental data. A simpler, one-dimensional finite-difference diffusion-dispersion model was also developed. One-dimensional simulations based on molecular diffusion also agreed well with experimental data. Simulations which incorporated mechanical dispersion tended to overestimate flux across the capillary fringe. Good agreement between the one- and two-dimensional models suggested that a simple, one-dimensional approximation of vertical transport across the capillary fringe can be useful when conditions are appropriate.

  6. Bioactivity of volatile organic compounds produced by Pseudomonas tolaasii

    PubMed Central

    Lo Cantore, Pietro; Giorgio, Annalisa; Iacobellis, Nicola S.

    2015-01-01

    Pseudomonas tolaasii is the main bacterial pathogen of several mushroom species. In this paper we report that strains of P. tolaasii produce volatile substances inducing in vitro mycelia growth inhibition of Pleurotus ostreatus and P. eryngii, and Agaricus bisporus and P. ostreatus basidiome tissue blocks brown discoloration. P. tolaasii strains produced the volatile ammonia but not hydrogen cyanide. Among the volatiles detected by GC–MS, methanethiol, dimethyl disulfide (DMDS), and 1-undecene were identified. The latter, when assayed individually as pure compounds, led to similar effects noticed when P. tolaasii volatiles natural blend was used on mushrooms mycelia and basidiome tissue blocks. Furthermore, the natural volatile mixture resulted toxic toward lettuce and broccoli seedling growth. In contrast, pure volatiles showed different activity according to their nature and/or doses applied. Indeed, methanethiol resulted toxic at all the doses used, while DMDS toxicity was assessed till a quantity of 1.25 μg, below which it caused, together with 1-undecene (≥10 μg), broccoli growth increase. PMID:26500627

  7. Evolution of volatile compounds during the development of cabernet sauvignon grapes (Vitis vinifera L.).

    PubMed

    Kalua, Curtis M; Boss, Paul K

    2009-05-13

    The evolution of volatile compounds was explored in grape berries at fortnightly intervals from fruit-set to late ripening to identify when biosynthetic pathways may be targeted for enhancement of grape and wine aroma. Stepwise linear discriminant analysis (SLDA) fully recognized patterns in berry physiological developmental stages with most of the variance (>99.0%) explained. The preveraison berry developmental stage was identified as a transition stage for volatile compound biosynthesis when most compounds were potentially sequestered to nonvolatile conjugates and berries lost their potential to synthesize esters and terpenes. Terpenes (predominantly eucalyptol, beta-caryophyllene, and alpha-humulene) characterized early berry development, whereas benzene derivatives (2-phenylethanol and 2-phenylethanal) appeared toward late ripening. Furthermore, C(6) volatile compounds changed from acetate esters to aldehydes and finally to alcohols during early, middle, and late berry developmental stages, respectively. The dominance of alcohols in the late stages of berry development, preceded by aldehydes, offers an opportunity for alcohols to aldehydes ratios to be used in the prediction of harvest timing for enhanced grape and wine aroma. The evolution of volatile compounds during berry development suggests a greater dependency on enzyme activity and specificity than extent of fatty acid unsaturation. The dependence of the stage of berry development on the accumulation of the products of alcohol dehydrogenase (ADH), alcohol acetyl transferase (AAT), and enal isomerase enzyme activity from the lipoxygenase pathway raises possibilities for the manipulation of aroma profiles in grapes and wines.

  8. Biogenic volatile organic compounds in the Earth system.

    PubMed

    Laothawornkitkul, Jullada; Taylor, Jane E; Paul, Nigel D; Hewitt, C Nicholas

    2009-01-01

    Biogenic volatile organic compounds produced by plants are involved in plant growth, development, reproduction and defence. They also function as communication media within plant communities, between plants and between plants and insects. Because of the high chemical reactivity of many of these compounds, coupled with their large mass emission rates from vegetation into the atmosphere, they have significant effects on the chemical composition and physical characteristics of the atmosphere. Hence, biogenic volatile organic compounds mediate the relationship between the biosphere and the atmosphere. Alteration of this relationship by anthropogenically driven changes to the environment, including global climate change, may perturb these interactions and may lead to adverse and hard-to-predict consequences for the Earth system.

  9. Food volatile compounds facilitating HII mesophase formation: solubilization and stability.

    PubMed

    Amar-Zrihen, Natali; Aserin, Abraham; Garti, Nissim

    2011-05-25

    Four lipophilic food volatile molecules of different chemical characteristics, phenylacetaldehyde, 2,6-dimethyl-5-heptenal, linalool, and trans-4-decenal, were solubilized into binary mixtures of monoolein/water, facilitating the formation of reverse hexagonal (H(II)) mesophases at room temperature without the need of solvents or triglycerides. Some of the flavor compounds are important building blocks of the hexagonal mesostructure, preventing phase transition with aging. The solubilization loads were relatively high: 12.6, 10.0, 12.6, and 10.0 wt % for phenylacetaldehyde, 2,6-dimethyl-5-heptenal, linalool, and trans-4-decenal, respectively. Phenylacetaldehyde formed mixtures of lamellar and cubic phases. Linalool, 2,6-dimethyl-5-heptenal, and trans-4-decenal induced structural shift from lamellar directly to H(II) mesophase, remaining stable at room temperature. Lattice parameters were found to increase with water content and to decrease with temperature and/or food volatile content. trans-4-Decenal produces more stable H(II) mesophase compared to linalool-loaded mesophase. At 40-60 °C, depending on the chemical structure and on the solubilization location of the food volatile compounds, the H(II) mesophase transforms to isotropic micellar phase, facilitating the release of the food volatile compounds. Molecular interactions suggest the existence of two consecutive stages in the solubilization process.

  10. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

    PubMed Central

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-01-01

    The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC) is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols. PMID:28287435

  11. Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors.

    PubMed

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-03-10

    The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC) is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols.

  12. Transport, behavior, and fate of volatile organic compounds in streams

    USGS Publications Warehouse

    Rathbun, R.E.

    1998-01-01

    Volatile organic compounds (VOCs) are compounds with chemical and physical properties that allow the compounds to move freely between the water and air phases of the environment. VOCs are widespread in the environment because of this mobility. Many VOCs have properties making them suspected or known hazards to the health of humans and aquatic organisms. Consequently, understanding the processes affecting the concentration and distribution VOCs in the environment is necessary. The U.S. Geological Survey selected 55 VOCs for study. This report reviews the characteristics of the various process that could affect the transport, behavior, and fate of these VOCs in streams.

  13. Correlation between volatile profiles of Italian fermented sausages and their size and starter culture.

    PubMed

    Montanari, Chiara; Bargossi, Eleonora; Gardini, Aldo; Lanciotti, Rosalba; Magnani, Rudy; Gardini, Fausto; Tabanelli, Giulia

    2016-02-01

    The aroma profiles of 10 traditional Italian fermented sausages were evaluated. The volatile organic compounds (VOCs) obtained by solid-phase microextraction and gas chromatograph-mass spectrometry were analysed using principal component analysis (PCA) and linear discriminant analysis (LDA). PCA allowed an acceptable separation but some sausage typologies were not well separated. On the other hand, the supervised approach of LDA allowed a clear grouping of the samples in relation to sausage size and starter culture. In spite of the extreme variability of the volatile profiles of the sausage typologies, this work showed the influence of diameter on VOC profile. The differences observed can be related to the effects that some fundamental physicochemical characteristics (such as water loss kinetics and oxygen availability) have on the results of ripening processes. Differences in VOC profiles were also observed due to the lactic acid bacteria used as starter cultures, with differences mainly attributable to compounds deriving from pyruvate metabolism.

  14. Encapsulation of Volatile Compounds in Silk Microparticles.

    PubMed

    Elia, Roberto; Guo, Jin; Budijono, Stephanie; Normand, Valery; Benczédi, Daniel; Omenetto, Fiorenzo; Kaplan, David L

    2015-07-01

    Various techniques have been employed to entrap fragrant oils within microcapsules or microparticles in the food, pharmaceutical, and chemical industries for improved stability and delivery. In the present work we describe the use of silk protein microparticles for encapsulating fragrant oils using ambient processing conditions to form an all-natural biocompatible matrix. These microparticles are stabilized via physical crosslinking, requiring no chemical agents, and are prepared with aqueous and ambient processing conditions using polyvinyl alcohol-silk emulsions. The particles were loaded with fragrant oils via direct immersion of the silk particles within an oil bath. The oil-containing microparticles were coated using alternating silk and polyethylene oxide layers to control the release of the oil from the microspheres. Particle morphology and size, oil loading capacity, release rates as well as silk-oil interactions and coating treatments were characterized. Thermal analysis demonstrated that the silk coatings can be tuned to alter both retention and release profiles of the encapsulated fragrance. These oil containing particles demonstrate the ability to adsorb and controllably release oils, suggesting a range of potential applications including cosmetic and fragrance utility.

  15. Encapsulation of Volatile Compounds in Silk Microparticles

    PubMed Central

    Elia, Roberto; Guo, Jin; Budijono, Stephanie; Normand, Valery; Benczédi, Daniel; Omenetto, Fiorenzo

    2015-01-01

    Various techniques have been employed to entrap fragrant oils within microcapsules or microparticles in the food, pharmaceutical, and chemical industries for improved stability and delivery. In the present work we describe the use of silk protein microparticles for encapsulating fragrant oils using ambient processing conditions to form an all-natural biocompatible matrix. These microparticles are stabilized via physical crosslinking, requiring no chemical agents, and are prepared with aqueous and ambient processing conditions using polyvinyl alcohol-silk emulsions. The particles were loaded with fragrant oils via direct immersion of the silk particles within an oil bath. The oil-containing microparticles were coated using alternating silk and polyethylene oxide layers to control the release of the oil from the microspheres. Particle morphology and size, oil loading capacity, release rates as well as silk-oil interactions and coating treatments were characterized. Thermal analysis demonstrated that the silk coatings can be tuned to alter both retention and release profiles of the encapsulated fragrance. These oil containing particles demonstrate the ability to adsorb and controllably release oils, suggesting a range of potential applications including cosmetic and fragrance utility. PMID:26568787

  16. Comparison of four extraction methods for analysis of volatile hop-derived aroma compounds in beer.

    PubMed

    Richter, Tobias M; Eyres, Graham T; Silcock, Patrick; Bremer, Phil J

    2017-09-09

    The volatile organic compound profile in beer is derived from hops, malt, yeast, and interactions between the ingredients, making it very diverse and complex. Due to the range and diversity of the volatile organic compounds present, the choice of the extraction method is extremely important for optimal sensitivity and selectivity. This study compared four extraction methods for hop-derived compounds in beer late hopped with Nelson Sauvin. Extraction capacity and variation were compared for headspace solid phase micro extraction, stir bar sorptive extraction, headspace sorptive extraction, and solvent assisted flavour evaporation. Generally, stir bar sorptive extraction was better suited for acids, headspace sorptive extraction for esters and aldehydes, while headspace solid phase micro extraction was less sensitive overall, extracting 40% fewer compounds. Solvent assisted flavour evaporation with dichloromethane was not suitable for the extraction of hop-derived volatile organic compounds in beer, as the profile was strongly skewed towards alcohols and acids. Overall, headspace sorptive extraction found to be best suited, closely followed by stir bar sorptive extraction. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. Determination on Monod kinetic coefficients for volatile hydrophobic organic compounds

    SciTech Connect

    Guha, S.; Jaffe, P.R.

    1996-06-20

    A new procedure is presented to determine Monod kinetic coefficients and the microbial yield coefficient for volatile hydrophobic compounds such as phenanthrene. Batch experiments were conducted with a mixed culture capable of degrading phenanthrene. The phenanthrene disappearance and carbon dioxide production were monitored with time. A maximum likelihood estimator was formulated to fit the set of equations that describe the system to the measured data. The model takes into account a number of processes such as partition onto the apparatus, volatilization, and partition onto the biomass. The parameters required to describe these processes were obtained by independent experiments. The yield coefficient could be determined within a small range. However, the specific growth rate and the half-saturation constant were found to vary widely, with pairs of them describing the system adequately. It was shown that partition and volatilization processes can significantly affect the determination of the yield and Monod kinetic coefficients and need to be taken into account.

  18. Volatile profile in the accurate labelling of monofloral honey. The case of lavender and thyme honey.

    PubMed

    Escriche, Isabel; Sobrino-Gregorio, Lara; Conchado, Andrea; Juan-Borrás, Marisol

    2017-07-01

    The proliferation of hybrid plant varieties without pollen, such as lavender, has complicated the classification of specific types of honey. This study evaluated the correlation between the proclaimed type of monofloral honey (lavender or thyme) as appears on the label with the actual percentage of pollen. In addition, physicochemical parameters, colour, olfacto-gustatory profile, and volatile compounds were tested. All of the samples labelled as lavender were wrongly classified according to the usual commercial criteria (minimum 10% of pollen Lavandula spp.). In the case of lavender honey, there was significant agreement between commercial labelling and classification through organoleptic perception (81.8%), and above all between the commercial labelling and the volatile compounds (90.9%). For thyme honey, agreement for both parameters was 90.0%. These results offer compelling evidence that the volatile compounds are useful for the classification of lavender honey with low levels of pollen since this technique agrees well with the organoleptic analysis.

  19. Sonochemical decomposition of volatile and non-volatile organic compounds--a comparative study.

    PubMed

    Goel, Mukesh; Hongqiang, Hu; Mujumdar, Arun S; Ray, Madhumita Bhowmick

    2004-11-01

    Sonochemical degradation which combines destruction of the target compounds by free radical reaction and thermal cleavage is one of the recent advanced oxidation processes (AOP) and proven to be effective for removing low concentration organic pollutants from aqueous streams. This work describes the degradation of several organic compounds of varying volatility in aqueous solution in two types of ultrasonic reactors. The process variables studied include initial concentration of the organics, temperature, and type of saturated gas. The effects of additional oxidant and electrolyte were also examined. A kinetic model was tested to determine its ability to predict the degradation rate constant of different volatile organic compounds at different initial conditions. A figure of merit for the electrical energy consumption for the two types of ultrasonic reactors is also presented.

  20. Effect of Se treatment on the volatile compounds in broccoli.

    PubMed

    Lv, Jiayu; Wu, Jie; Zuo, Jinhua; Fan, Linlin; Shi, Junyan; Gao, Lipu; Li, Miao; Wang, Qing

    2017-02-01

    Broccoli contains high levels of bioactive compounds but deteriorates and senesces easily. In the present study, freshly harvested broccoli was treated with selenite and stored at two different temperatures. The effect of selenite treatment on sensory quality and postharvest physiology were analyzed. Volatile components were assessed by HS-SPME combined with GC-MS and EN. The metabolism of Se and S was also examined. Results indicated that Se treatment had a significant effect on maintaining the sensory quality, suppressing the respiration intensity and ethylene production, as well as increasing the content of Se and decreasing the content of S. In particular, significant differences in the composition of volatile compounds were present between control and Se-treated. The differences were mainly due to differences in alcohols and sulfide compounds. These results demonstrate that Se treatment can have a positive effect on maintaining quality and enhancing its sensory quality through the release of volatile compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. New graphene fiber coating for volatile organic compounds analysis.

    PubMed

    Zhang, GuoJuan; Guo, XiaoXi; Wang, ShuLing; Wang, XueLan; Zhou, YanPing; Xu, Hui

    2014-10-15

    In the work, a novel graphene-based solid phase microextraction-gas chromatography/mass spectrometry method was developed for the analysis of trace amount of volatile organic compounds in human exhaled breath vapor. The graphene fiber coating was prepared by a one-step hydrothermal reduction reaction. The fiber with porous and wrinkled structure exhibited excellent extraction efficiency toward eight studied volatile organic compounds (two n-alkanes, five n-aldehydes and one aromatic compound). Meanwhile, remarkable thermal and mechanical stability, long lifespan and low cost were also obtained for the fiber. Under the optimal conditions, the developed method provided low limits of detection (1.0-4.5ngL(-1)), satisfactory reproducibility (3.8-13.8%) and acceptable recoveries (93-122%). The method was applied successfully to the analysis of breath samples of lung cancer patients and healthy individuals. The unique advantage of this approach includes simple setup, non-invasive analysis, cost-efficient and sufficient sensitivity. The proposed method supply us a new possibility to monitor volatile organic compounds in human exhaled breath samples.

  2. Determination of some volatile compounds in alcoholic beverage by headspace solid-phase microextraction gas chromatography - mass spectrometry

    NASA Astrophysics Data System (ADS)

    Schmutzer, G.; Avram, V.; Feher, I.; David, L.; Moldovan, Z.

    2012-02-01

    The volatile composition of alcoholic beverage was studied by headspace solid-phase microextraction (HSSPME) method and gas chromatography - mass spectrometry (GC-MS). Some volatile compounds, such as alcohols, esters, terpenes and other are mainly responsible for the flavor of fortified wines and their amounts specify the quality of the alcoholic beverages. From this perspective it is interesting to develop a rapid, selective and sensitive analytical method suitable for simultaneous quantification of the main molecules being responsible for the organoleptic characteristic of alcoholic beverages. Vermouth fortified drink was analyzed in order to characterize the volatile profile. Using the HS-SPME/GC-MS a number of twenty-six volatile compounds from a commercial market alcoholic beverage were identified. The most abundant compounds were m-thymol, o-thymol and eugenol, alongside of the ethyl ester compounds.

  3. Analysis of volatile compounds released during the grinding of roasted coffee beans using solid-phase microextraction.

    PubMed

    Akiyama, Masayuki; Murakami, Kazuya; Ohtani, Noboru; Iwatsuki, Keiji; Sotoyama, Kazuyoshi; Wada, Akira; Tokuno, Katsuya; Iwabuchi, Hisakatsu; Tanaka, Kiyofumi

    2003-03-26

    A dynamic solid-phase microextraction (SPME) method to sample fresh headspace volatile compounds released during the grinding of roasted coffee beans was described and the analytical results using gas chromatography/mass spectrometry (GC/MS) and GC/olfactometry (GC/O) were compared to those of the conventional static SPME sampling methods using ground coffee. Volatile compounds released during the grinding of roasted coffee beans (150 g) were obtained by exposing the SPME fiber (poly(dimethylsiloxane)/divinylbenzene, PDMS/ DVB) for 8 min to nitrogen gas (600 mL/min) discharged from a glass vessel in which the electronic coffee grinder was enclosed. Identification and characterization of volatile compounds thus obtained were achieved by GC/MS and GC/O. Peak areas of 47 typical coffee volatile compounds, separated on total ion chromatogram (TIC), obtained by the dynamic SPME method, showed coefficients of variation less than 5% (n = 3) and the gas chromatographic profile of volatile compounds thus obtained was similar to that of the solvent extract of ground coffee, except for highly volatile compounds such as 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 4-ethenyl-2-methoxyphenol. Also, SPME dilution analysis of volatile compounds released during the grinding of roasted coffee beans showed linear plots of peak area versus exposed fiber length (R (2) > 0.89). Compared with those of the headspace volatile compounds of ground coffee using GC/MS and GC/O, the volatile compounds generated during the grinding of roasted coffee beans were rich in nutty- and smoke-roast aromas.

  4. Propolis volatile compounds: chemical diversity and biological activity: a review

    PubMed Central

    2014-01-01

    Propolis is a sticky material collected by bees from plants, and used in the hive as building material and defensive substance. It has been popular as a remedy in Europe since ancient times. Nowadays, propolis use in over-the-counter preparations, “bio”-cosmetics and functional foods, etc., increases. Volatile compounds are found in low concentrations in propolis, but their aroma and significant biological activity make them important for propolis characterisation. Propolis is a plant-derived product: its chemical composition depends on the local flora at the site of collection, thus it offers a significant chemical diversity. The role of propolis volatiles in identification of its plant origin is discussed. The available data about chemical composition of propolis volatiles from different geographic regions are reviewed, demonstrating significant chemical variability. The contribution of volatiles and their constituents to the biological activities of propolis is considered. Future perspectives in research on propolis volatiles are outlined, especially in studying activities other than antimicrobial. PMID:24812573

  5. Effect of different cooking methods on lipid oxidation and formation of volatile compounds in foal meat.

    PubMed

    Domínguez, Rubén; Gómez, María; Fonseca, Sonia; Lorenzo, José M

    2014-06-01

    The influence of four different cooking methods (roasting, grilling, microwaving and frying) on cooking loss, lipid oxidation and volatile profile of foal meat was studied. Cooking loss were significantly (P<0.001) affected by thermal treatment, being higher (32.5%) after microwaving and lower after grilling (22.5%) and frying (23.8%). As expected, all the cooking methods increased TBARs content, since high temperature during cooking causes increased oxidation in foal steaks, this increase was significantly (P<0.001) higher when foal steaks were microwaved or roasted. The four different cooking methods led to increased total volatile compounds (between 366.7 and 633.1AU×10(6)/g dry matter) compared to raw steaks (216.4AU×10(6)/g dry matter). The roasted steaks showed the highest volatile content, indicating that increased cooking temperature increases the formation of volatile compounds. Aldehydes were the most abundant compounds in cooked samples, with amounts of 217.2, 364.5, 283.5 and 409.1AU×10(6)/g dry matter in grilled, microwaved, fried and roasted samples, respectively, whereas esters were the most abundant compounds in raw samples, with mean amounts of 98.8AU×10(6)/g dry matter. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Catalytic combustion of volatile organic compounds.

    PubMed

    Everaert, K; Baeyens, J

    2004-06-18

    Despite the success of adsorption and thermal incineration of (C)VOC emissions, there is still a need for research on techniques which are both economically more favorable and actually destroy the pollutants rather than merely remove them for recycling elsewhere in the biosphere. The catalytic destruction of (C)VOC to CO2, H2O and HCl/Cl2 appears very promising in this context and is the subject of the present paper. The experiments mainly investigate the catalytic combustion of eight target compounds, all of which are commonly encountered in (C)VOC emissions and/or act as precursors for the formation of PCDD/F. Available literature on the different catalysts active in the oxidation of (C)VOC is reviewed and the transition metal oxide complex V2O5-WO3/TiO2 appears most suitable for the current application. Different reactor geometries (e.g. fixed pellet beds, honeycombs, etc.) are also described. In this research a novel catalyst type is introduced, consisting of a V2O5-WO3/TiO2 coated metal fiber fleece. The conversion of (C)VOC by thermo-catalytic reactions is governed by both reaction kinetics and reaction equilibrium. Full conversion of all investigated VOC to CO2, Cl2, HCl and H2O is thermodynamically feasible within the range of experimental conditions used in this work (260-340 degrees C, feed concentrations 30-60 ppm). A first-order rate equation is proposed for the (C)VOC oxidation reactions. The apparent rate constant is a combination of reaction kinetics and mass transfer effects. The oxidation efficiencies were measured with various (C)VOC in the temperature range of 260-340 degrees C. Literature data for oxidation reactions in fixed beds and honeycomb reactors are included in the assessment. Mass transfer resistances are calculated and are generally negligible for fleece reactors and fixed pellet beds, but can be of importance for honeycomb monoliths. The experimental investigations demonstrate: (i) that the conversion of the hydrocarbons is

  7. Removal of volatile organic compounds from paper coatings

    NASA Astrophysics Data System (ADS)

    Meier, Dirk; Warnecke, Hans-Joachim; Pruess, Jan

    1997-08-01

    From the chemical point of view paper coatings are mainly polymer dispersions. Polymer dispersions are constituted in multitude fields, for example as dispersion coatings or adhesives. As far as no additional treatment is done, polymer materials as well as polymer agents contain non polymer, volatile organic components that may arise from: (1) incomplete polymerization of the applied monomers, (2) primary materials containing non polymerizable components, (3) undesirable side reactions during the synthesis. Requirements for the removal of volatile substances from polymer dispersion are given by several reasons: (1) low molecular substances deteriorate the product characteristics (viscosity, thermal stability and others), (2) in order to comply with legislative standards, volatile organic compounds have to be removed from dispersions, especially when applied to large surfaces (e.g. in surface refining in paper and leather industries as well as on coating). The removal of volatile organic compounds (deodorization) can be realized in continuous or discontinuous processes. In contrast to highly developed process technology, the process itself is not well understood, especially mass transport phenomena between the gas phase and the aqueous polymer dispersion are insufficiently and controversially discussed in the literature. Two processes, their advantages and disadvantages and the description by mathematical- mechanistic models are presented in this paper.

  8. GCMS investigation of volatile compounds in green coffee affected by potato taste defect and the Antestia bug.

    PubMed

    Jackels, Susan C; Marshall, Eric E; Omaiye, Angelica G; Gianan, Robert L; Lee, Fabrice T; Jackels, Charles F

    2014-10-22

    Potato taste defect (PTD) is a flavor defect in East African coffee associated with Antestiopsis orbitalis feeding and 3-isopropyl-2-methoxypyrazine (IPMP) in the coffee. To elucidate the manifestation of PTD, surface and interior volatile compounds of PTD and non-PTD green coffees were sampled by headspace solid phase microextraction and analyzed by gas chromatography mass spectrometry. Principal component analysis of the chromatographic data revealed a profile of surface volatiles distinguishing PTD from non-PTD coffees dominated by tridecane, dodecane, and tetradecane. While not detected in surface volatiles, IPMP was found in interior volatiles of PTD coffee. Desiccated antestia bugs were analyzed by GCMS, revealing that the three most prevalent volatiles were tridecane, dodecane, and tetradecane, as was found in the surface profile PTD coffee. Coffee having visible insect damage exhibited both a PTD surface volatile profile and IPMP in interior volatiles, supporting the hypothesis linking antestia bug feeding activity with PTD profile compounds on the surface and IPMP in the interior of the beans.

  9. Analytical methods for volatile compounds in wheat bread.

    PubMed

    Pico, Joana; Gómez, Manuel; Bernal, José; Bernal, José Luis

    2016-01-08

    Bread aroma is one of the main requirements for its acceptance by consumers, since it is one of the first attributes perceived. Sensory analysis, crucial to be correlated with human perception, presents limitations and needs to be complemented with instrumental analysis. Gas chromatography coupled to mass spectrometry is usually selected as the technique to determine bread volatile compounds, although proton-transfer reaction mass spectrometry begins also to be used to monitor aroma processes. Solvent extraction, supercritical fluid extraction and headspace analysis are the main options for the sample treatment. The present review focuses on the different sample treatments and instrumental alternatives reported in the literature to analyse volatile compounds in wheat bread, providing advantages and limitations. Usual parameters employed in these analytical methods are also described.

  10. [Design of artificial foetor flatus based on bacterial volatile compounds].

    PubMed

    Justesen, Ulrik Stenz

    2016-12-12

    Excessive flatulence can be a huge social problem. The purpose of this study was to design artificial flatus from bacterial volatile compounds to stimulate research into neutralizing measures. Anaerobic bacteria, representing a broad spectrum, from a recognized international culture collection were included. The strains were incubated in an anaerobic jar. After 24 hours the lid was removed, and the odour was evaluated by a specialist in clinical microbiology. Four different anaerobic strains were chosen for further studies based on their individual odours. In total, seven different combinations of two or three strains were tested. The combination of Bacteroides fragilis ATCC 25285, Clostridium difficile ATCC 700057 and Fusobacterium necrophorum ATCC 25286 was chosen as it had a suitably foul odour. It is possible to design artificial flatus from bacterial volatile compounds. The method is easy and inexpensive and can stimulate further research into neutralizing measures. none. none.

  11. Scalping of light volatile sulfur compounds by wine closures.

    PubMed

    Silva, Maria A; Jourdes, Michaël; Darriet, Philippe; Teissedre, Pierre-Louis

    2012-11-07

    Closures have an important influence on wine quality during aging in a bottle. Closures have a direct impact on oxygen exposure and on volatiles scavenging in wine. Model wine solution soaking assays of several types of closures (i.e., natural and technical cork stoppers, synthetic closures, screw caps) with two important wine volatile sulfur compounds led to a considerable reduction in their levels. After 25 days, cork closures and synthetic closures, to a lesser extent, have significantly scavenged hydrogen sulfide and dimethyl sulfide. These compounds have a determinant impact on wine aging bouquet, being largely responsible for "reduced off-flavors". Hydrogen sulfide levels are often not well correlated with the exposure of wine to oxygen or with the permeability of the closure. Its preferential sorption by some types of closures may explain that behavior. Scalping phenomenon should be taken into account when studying wine post-bottling development.

  12. Chemometric evaluation of the volatile profile of probiotic melon and probiotic cashew juice.

    PubMed

    de Godoy Alves Filho, Elenilson; Rodrigues, Tigressa Helena Soares; Fernandes, Fabiano André Narciso; Pereira, Ana Lucia Fernandes; Narain, Narendra; de Brito, Edy Sousa; Rodrigues, Sueli

    2017-09-01

    The aim of this study was to evaluate the influence of the lactic acid fermentation on volatile compounds of melon and cashew apple juices. The effect of the fermentation processing on the volatile profile of probiotic juices was assessed by HS-SPME/GC-MS coupled to chemometrics with 67.9% and 81.0% of the variance in the first principal component for melon and cashew juices, respectively. The Lactobacillus casei fermentation imparted a reduction of ethyl butanoate, ethyl-2-methylbutirate, and ethyl hexanoate for melon juice; and of ethyl acetate, ethyl-2-methyl butanoate, ethyl crotonate, ethyl isovalerate, benzaldehyde, and ethyl hexanoate for cashew juice. Measurements of the stability of these compounds and the formation of the component 3-methyl-2-butenyl in melon juice may be used as a volatile marker to follow the juice fermentation. These findings suggested that even though it is not a dairy product the lactic acid fermentation of fruits developed a volatile profile combining the fruit and lactic acid fermentation volatiles with mildly formation or degradation of aroma compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. 78 FR 11119 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of trans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... AGENCY 40 CFR Part 51 RIN 2060-AQ38 Air Quality: Revision to Definition of Volatile Organic Compounds...: Proposed rule. SUMMARY: The EPA is proposing to revise the definition of volatile organic compounds (VOCs..., Reporting and recordkeeping requirements, Volatile organic compounds. Dated: February 4, 2013. Lisa...

  14. Effect of sugars on liquid-vapour partition of volatile compounds in ready-to-drink coffee beverages.

    PubMed

    Piccone, P; Lonzarich, V; Navarini, L; Fusella, G; Pittia, P

    2012-09-01

    The effect of sugars (sucrose, lactose, glucose, fructose, 10%w/v) on the liquid-vapour partition of selected volatile compounds of coffee beverages has been investigated in espresso coffee and ready-to-drink (RTD) canned coffee prepared and obtained by using the same Arabica roasted coffee beans blend. Aroma composition of coffee beverages has been preliminary investigated by headspace-gas chromatography (HS-GC) and solid phase microextraction-HS-GC-mass spectrometry to characterize the volatile pattern of the systems and to evaluate the effects of sugars on the aroma release/retention. Then, the liquid-vapour partition coefficient (k) of 4 selected key aroma compounds (diacetyl, 2,3-pentanedione, ethylpyrazine, hexanal) was determined in water, sugars solutions as well as RTD coffee brews added with the same sugars (10%w/v). Sugars added in coffee beverages affected the release of the volatiles and thus its aroma profile with differences due to the type of added sugar and coffee brew type. The k values of the selected volatile compounds resulted different depending on the model system composition (water, coffee brew) and sugar type added. In particular, melanoidins as well as other non-volatile components (lipids, acids, carbohydrates) in the RTD coffee brews could be implied in the change of k of the volatile compounds in respect to that observed in water. The effects of the sugar type on the release/retention of the four key coffee aroma compounds were partly explained in terms of 'salting out' especially for the more polar volatile compounds and in the sucrose-added model systems. The change of chemical and physico-chemical properties of the water and brews induced by the sugars as well as the occurrence of interactions between volatile compounds and non-volatile components may be implied in the reduction of the vapour partition of the aroma compounds. Copyright © 2012 John Wiley & Sons, Ltd.

  15. Are Some Fungal Volatile Organic Compounds (VOCs) Mycotoxins?

    PubMed Central

    Bennett, Joan W.; Inamdar, Arati A.

    2015-01-01

    Volatile organic compounds (VOCs) are carbon-compounds that easily evaporate at room temperature. Toxins are biologically produced poisons; mycotoxins are those toxins produced by microscopic fungi. All fungi emit blends of VOCs; the qualitative and quantitative composition of these volatile blends varies with the species of fungus and the environmental situation in which the fungus is grown. These fungal VOCs, produced as mixtures of alcohols, aldehydes, acids, ethers, esters, ketones, terpenes, thiols and their derivatives, are responsible for the characteristic moldy odors associated with damp indoor spaces. There is increasing experimental evidence that some of these VOCs have toxic properties. Laboratory tests in mammalian tissue culture and Drosophila melanogaster have shown that many single VOCs, as well as mixtures of VOCs emitted by growing fungi, have toxic effects. This paper describes the pros and cons of categorizing toxigenic fungal VOCs as mycotoxins, uses genomic data to expand on the definition of mycotoxin, and summarizes some of the linguistic and other conventions that can create barriers to communication between the scientists who study VOCs and those who study toxins. We propose that “volatoxin” might be a useful term to describe biogenic volatile compounds with toxigenic properties. PMID:26402705

  16. Are Some Fungal Volatile Organic Compounds (VOCs) Mycotoxins?

    PubMed

    Bennett, Joan W; Inamdar, Arati A

    2015-09-22

    Volatile organic compounds (VOCs) are carbon-compounds that easily evaporate at room temperature. Toxins are biologically produced poisons; mycotoxins are those toxins produced by microscopic fungi. All fungi emit blends of VOCs; the qualitative and quantitative composition of these volatile blends varies with the species of fungus and the environmental situation in which the fungus is grown. These fungal VOCs, produced as mixtures of alcohols, aldehydes, acids, ethers, esters, ketones, terpenes, thiols and their derivatives, are responsible for the characteristic moldy odors associated with damp indoor spaces. There is increasing experimental evidence that some of these VOCs have toxic properties. Laboratory tests in mammalian tissue culture and Drosophila melanogaster have shown that many single VOCs, as well as mixtures of VOCs emitted by growing fungi, have toxic effects. This paper describes the pros and cons of categorizing toxigenic fungal VOCs as mycotoxins, uses genomic data to expand on the definition of mycotoxin, and summarizes some of the linguistic and other conventions that can create barriers to communication between the scientists who study VOCs and those who study toxins. We propose that "volatoxin" might be a useful term to describe biogenic volatile compounds with toxigenic properties.

  17. Volatilization of mercury compounds by methylmercury-volatilizing bacteria in Minamata Bay sediment

    SciTech Connect

    Nakamura, K.; Sakata, T.; Nakahara, H.

    1988-11-01

    Minamata Bay has been heavily polluted by high mercury concentrations which gave rise for a long time to methylmercury poisoning, Minamata disease (Kutsuna 1968; Irukayama 1977). The mercury still exists in the sediments of the Bay. The population of mercury-resistant bacteria in the sediments of Minamata Bay is larger than that in the sediments of other marine environments. The mercury-resistant bacteria isolated from a marine environment have been found to transform organic and inorganic mercury compounds into mercury vapor. The mercury-resistance confirmed in various bacterial genera has been shown to be plasmid-mediated volatilization. However, there has been little definitive information on the volatilization of organic mercury by the bacteria living in the mercury-polluted environment. It is important to know what bacterial transformations of mercury have been taking place and how the mercury-resistant bacteria may be playing a role in the mercury cycle in the marine environment of Minamata Bay. The object of the present study is to clarify the characteristics of the methylmercury-volatilizing bacteria in the sediments of Minamata Bay and of the volatilization of various mercury compounds by these bacteria.

  18. Volatile organic compound (VOC) emissions during malting and beer manufacture

    NASA Astrophysics Data System (ADS)

    Gibson, Nigel B.; Costigan, Gavin T.; Swannell, Richard P. J.; Woodfield, Michael J.

    Estimates have been made of the amounts of volatile organic compounds (VOCs) released during different stages of beer manufacture. The estimates are based on recent measurements and plant specification data supplied by manufacturers. Data were obtained for three main manufacturing processes (malting, wort processing and fermentation) for three commercial beer types. Some data on the speciation of emitted compounds have been obtained. Based on these measurements, an estimate of the total unabated VOC emission. from the U.K. brewing industry was calculated as 3.5 kta -1, over 95% of which was generated during barley malting. This value does not include any correction for air pollution control.

  19. Dynamic headspace analysis of the release of volatile organic compounds from ethanolic systems by direct APCI-MS.

    PubMed

    Tsachaki, Maroussa; Linforth, Robert S T; Taylor, Andrew J

    2005-10-19

    Static equilibrium headspace was diluted with a stream of nitrogen to study the stability of the volatile headspace concentration. The headspace dilution profile of 18 volatile compounds above aqueous and ethanolic solutions was measured in real time using atmospheric pressure chemical ionization-mass spectrometry. Under dynamic conditions the volatiles headspace concentration above water solutions decreased readily upon dilution. The presence of ethanol helped to maintain the volatile headspace concentration when the ethanol solution concentration was above 50 mL/L. This effect was such that under dynamic conditions the absolute volatile concentration above an ethanolic solution was higher than that above an aqueous solution, contrary to results observed in equilibrium studies. The ratio of the headspace concentration of volatiles above ethanolic 120 mL/L and water solutions was correlated to their air/water partition coefficient.

  20. Volatile organic compounds produced by the phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria 85-10.

    PubMed

    Weise, Teresa; Kai, Marco; Gummesson, Anja; Troeger, Armin; von Reuß, Stephan; Piepenborn, Silvia; Kosterka, Francine; Sklorz, Martin; Zimmermann, Ralf; Francke, Wittko; Piechulla, Birgit

    2012-01-01

    Xanthomonas campestris is a phytopathogenic bacterium and causes many diseases of agricultural relevance. Volatiles were shown to be important in inter- and intraorganismic attraction and defense reactions. Recently it became apparent that also bacteria emit a plethora of volatiles, which influence other organisms such as invertebrates, plants and fungi. As a first step to study volatile-based bacterial-plant interactions, the emission profile of Xanthomonas c. pv. vesicatoria 85-10 was determined by using GC/MS and PTR-MS techniques. More than 50 compounds were emitted by this species, the majority comprising ketones and methylketones. The structure of the dominant compound, 10-methylundecan-2-one, was assigned on the basis of its analytical data, obtained by GC/MS and verified by comparison of these data with those of a synthetic reference sample. Application of commercially available decan-2-one, undecan-2-one, dodecan-2-one, and the newly synthesized 10-methylundecan-2-one in bi-partite Petri dish bioassays revealed growth promotions in low quantities (0.01 to 10 μmol), whereas decan-2-one at 100 μmol caused growth inhibitions of the fungus Rhizoctonia solani. Volatile emission profiles of the bacteria were different for growth on media (nutrient broth) with or without glucose.

  1. Volatile organic compounds in Gulf of Mexico sediments

    SciTech Connect

    McDonald, T.J.

    1988-01-01

    Volatile organic compounds (VOC), concentrations and compositions were documented for estuarine, coastal, shelf, slope, and deep water sediments from the Gulf of Mexico. VOC were measured (detection limit >0.01 ppb) using a closed-loop stripping apparatus with gas chromatography (GC) and flame ionization, flame photometric, and mass spectrometric detectors. The five primary sources of Gulf of Mexico sediment VOC are: (1) planktonic and benthic fauna and flora; (2) terrestrial material from riverine and atmospheric deposition; (3) anthropogenic inputs: (4) upward migration of hydrocarbons; and (5) transport by bottom currents or slumping. Detected organo-sulfur compounds include alkylated sulfides, thiophene, alkylated thiophenes, and benzothiophenes. Benzothiophenes are petroleum related. Low molecular weight organo-sulfur compounds result from the biological oxidation of organic matter. A lack of organosulfur compounds in the reducing environment of the Orca Basin may result from a lack of free sulfides which are necessary for their production.

  2. [Binding of Volatile Organic Compounds to Edible Biopolymers].

    PubMed

    Misharina, T A; Terenina, M B; Krikunova, N I; Medvedeva, I B

    2016-01-01

    Capillary gas chromatography was used to study the influence of the composition and structure of different edible polymers (polysaccharides, vegetable fibers, and animal protein gelatin) on the binding of essential oil components. The retention of volatile organic compounds on biopolymers was shown to depend on their molecule structure and the presence, type, and position of a functional group. The maximum extent of the binding was observed for nonpolar terpene and sesquiterpene hydrocarbons, and the minimum extent was observed for alcohols. The components of essential oils were adsorbed due mostly to hydrophobic interactions. It was shown that the composition and structure of a compound, its physico-chemical state, and the presence of functional groups influence the binding. Gum arabic and guar gum were found to bind nonpolar compounds to a maximum and minimum extent, respectively. It was demonstrated the minimum adsorption ability of locust bean gum with respect to all studied compounds.

  3. Volatile organic compounds associated with Plasmodium falciparum infection in vitro.

    PubMed

    Correa, Ricardo; Coronado, Lorena M; Garrido, Anette C; Durant-Archibold, Armando A; Spadafora, Carmenza

    2017-05-02

    In order to identify new ways to prevent transmission of vector-borne diseases such as malaria, efforts have been made to understand how insects are attracted to humans. Vector-host interaction studies have shown that several volatile compounds play an important role in attracting mosquitoes to human targets. A headspace solid-phase micro-extraction/gas chromatography-mass spectrometry (HSPME GC-MS) analysis of the volatile organic composition of extracellular vesicles (EVs) and supernatants of ultracentrifugation (SNUs) was carried out in Plasmodium falciparum-infected cultures with high and low parasitemias. A list of 18 volatile organic compounds (VOCs) was obtained from the EVs of both infected and uninfected RBCs with 1,2,3-Propanetriol, diacetate (diacetin) increased in the infected EVs, regardless of the parasitemia of the culture. The supernatant analysis, however, gave off 56 VOCs, with pentane 2,2,4-trimethyl being present in all the SNUs of uninfected erythrocytes but absent from the parasite-infected ones. Standing out in this study was hexanal, a reported insect attractant, which was the only VOC present in all samples from SNUs from infected erythrocytes and absent from uninfected ones, suggesting that it originates during parasite infection. The hexanal compound, reportedly a low-level component found in healthy human samples such as breath and plasma, had not been found in previous analyses of P. falciparum-infected patients or cultures. This compound has been reported as an Anopheles gambiae attractant in plants. While the compound could be produced during infection by the malaria parasite in human erythrocytes, the A. gambiae attraction could be used by the parasite as a strategy for transmission.

  4. Identification of volatile compounds associated with the aroma of white strawberries (Fragaria chiloensis).

    PubMed

    Prat, Loreto; Espinoza, María Inés; Agosin, Eduardo; Silva, Herman

    2014-03-15

    Fragaria chiloensis (L.) Mill spp. chiloensis form chiloensis, is a strawberry that produces white fruits with unique aromas. This species, endemic to Chile, is one of the progenitors of Fragaria x ananassa Duch. In order to identify the volatile compounds that might be responsible for aroma, these were extracted, and analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O) and compared with sensory analyses. Three methods of extraction were used: solvent-assisted evaporation (SAFE), headspace solid phase micro-extraction (HS-SPME) and liquid-liquid extraction (LLE). Ninety-nine volatile compounds were identified by GC-MS, of which 75 showed odor activity using GC-O. Based on the highest dilution factor (FD = 1000) and GC-O intensity ≥2, we determined 20 major compounds in white strawberry fruit that contribute to its aroma. We chose 51 compounds to be tested against their commercial standards. The identities were confirmed by comparison of their linear retention indices against the commercial standards. The aroma of white strawberry fruits was reconstituted with a synthetic mixture of most of these compounds. The volatile profile of white strawberry fruit described as fruity, green-fresh, floral, caramel, sweet, nutty and woody will be a useful reference for future strawberry breeding programs. © 2013 Society of Chemical Industry.

  5. Characterization of volatile compounds responsible for the aroma in naturally fermented sausages by gas chromatography-olfactometry.

    PubMed

    Olivares, Alicia; Navarro, José Luis; Flores, Mónica

    2015-03-01

    The objective of this study was to characterize naturally fermented dry sausages produced without the use of microbial starters and to determine which odour-active compounds are responsible for their aroma. The traditional manufacture was responsible for different chemical characteristics and consumer's acceptance. The volatile compounds detected in the headspace comprised a complex mixture of volatile compounds derived from bacterial metabolism (mainly esterase activity of Staphyloccoci), spices and lipid auto-oxidation. The odour-active volatile compounds were identified using gas chromatography coupled to olfactometry (GC-O) using the detection frequency method. The aroma profile was characterized by the presence of several compounds such as acetic acid, ethyl butanoate, hexanal, methional, 1-octen-3-ol, benzeneacetaldehyde and 4-methyl-phenol. However, naturally fermented sausages were also characterized by numerous esters, both ethyl and methyl esters, which impart a wide variety of fruity notes.

  6. Effect of different drying techniques on bioactive components, fatty acid composition, and volatile profile of robusta coffee beans.

    PubMed

    Dong, Wenjiang; Hu, Rongsuo; Chu, Zhong; Zhao, Jianping; Tan, Lehe

    2017-11-01

    This study investigated the effect of different drying techniques, namely, room-temperature drying (RTD), solar drying (SD), heat-pump drying (HPD), hot-air drying (HAD), and freeze drying (FD), on bioactive components, fatty acid composition, and the volatile compound profile of robusta coffee beans. The data showed that FD was an effective method to preserve fat, organic acids, and monounsaturated fatty acids. In contrast, HAD was ideal for retaining polyunsaturated fatty acids and amino acids. Sixty-two volatile compounds were identified in the differently dried coffee beans, representing 90% of the volatile compounds. HPD of the coffee beans produced the largest number of volatiles, whereas FD resulted in the highest volatile content. A principal component analysis demonstrated a close relationship between the HPD, SD, and RTD methods whereas the FD and HAD methods were significantly different. Overall, the results provide a basis for potential application to other similar thermal sensitive materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Characteristics of the volatile organic compounds -- Arid Integrated Demonstration Site

    SciTech Connect

    Last, G.V.; Lenhard, R.J.; Bjornstad, B.N.; Evans, J.C.; Roberson, K.R.; Spane, F.A.; Amonette, J.E.; Rockhold, M.L.

    1991-10-01

    The Volatile Organic Compounds -- Arid Integrated Demonstration Program (VOC-Arid ID) is targeted at demonstration and testing of technologies for the evaluation and cleanup of volatile organic compounds and associated contaminants at arid DOE sites. The initial demonstration site is an area of carbon tetrachloride (CCl{sub 4}) contamination located near the center of the Hanford Site. The movement of CCl{sub 4} and other volatile organic contaminants in the subsurface is very complex. The problem at the Hanford Site is further complicated by the concurrent discharge of other waste constituents including acids, lard oil, organic phosphates, and transuranic radionuclides. In addition, the subsurface environment is very complex, with large spatial variabilities in hydraulic properties. A thorough understanding of the problem is essential to the selection of appropriate containment, retrieval, and/or in situ remedial technologies. The effectiveness of remedial technologies depends on knowing where the contaminants are, how they are held up in a given physical and chemical subsurface environment; and knowing the physical, chemical, and microbiological changes that are induced by the various remedial technologies.

  9. 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.

  10. Measurement of volatile organic compounds in human blood.

    PubMed Central

    Ashley, D L; Bonin, M A; Cardinali, F L; McCraw, J M; Wooten, J V

    1996-01-01

    Volatile organic compounds (VOCs) are an important public health problem throughout the developed world. Many important questions remain to be addressed in assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in the analytical determination of VOCs. The analytical methodology chosen to measure toxicants in biological materials must be well validated and carefully carried out; poor quality assurance can lead to invalid results that can have a direct bearing on treating exposed persons. The pharmacokinetics of VOCs show that most of the internal dose of these compounds is quickly eliminated, but there is a fraction that is only slowly removed, and these compounds may bioaccumulate. VOCs are found in the general population at the high parts-per-trillion range, but some people with much higher levels have apparently been exposed to VOC sources away from the workplace. Smoking is the most significant confounder to internal dose levels of VOCs and must be considered when evaluating suspected cases of exposure. PMID:8933028

  11. Emission of volatile organic compounds (VOCs) from PVC floor coverings.

    PubMed

    Wiglusz, R; Igielska, B; Sitko, E; Nikel, G; Jarnuszkiewicz, I

    1998-01-01

    In this study 29 PVC floor coverings were tested for emission of vinyl chloride (VC) and other volatile organic compounds (VOCs). A study on the effect of higher temperature on emission of VOCs from newly manufactured PVC flooring was also carried out. The study was conducted in climatic chamber, according to Polish Standard PN-89/Z-04021. GC method was used for analyzing of the compounds emitted. VC was not emitted from any of the floorings tested. Other VOCs were emitted in different concentrations. The influence of temperature on emission was conducted at temperatures of 23 degrees C and 35 degrees C from 2 hrs up to 180 days after introduction of materials in the chamber. The increase of temperature caused increase of total volatile organic compounds (TVOC) emission during 24 hrs of experiment. Then the emission was comparable for both temperatures. After 9 days emission of identified and unidentified compounds (TVOC) showed a rapid decay and stayed on very low level during a few months. The study conducted showed that PVC floorings after 10 days of installation in the room should not be source of indoor air contamination.

  12. Speciation of volatile organic compounds from poultry production

    NASA Astrophysics Data System (ADS)

    Trabue, Steven; Scoggin, Kenwood; Li, Hong; Burns, Robert; Xin, Hongwei; Hatfield, Jerry

    2010-09-01

    Volatile organic compounds (VOCs) emitted from poultry production are leading source of air quality problems. However, little is known about the speciation and levels of VOCs from poultry production. The objective of this study was the speciation of VOCs from a poultry facility using evacuated canisters and sorbent tubes. Samples were taken during active poultry production cycle and between production cycles. Levels of VOCs were highest in areas with birds and the compounds in those areas had a higher percentage of polar compounds (89%) compared to aliphatic hydrocarbons (2.2%). In areas without birds, levels of VOCs were 1/3 those with birds present and compounds had a higher total percentage of aliphatic hydrocarbons (25%). Of the VOCs quantified in this study, no single sampling method was capable of quantifying more than 55% of compounds and in several sections of the building each sampling method quantified less than 50% of the quantifiable VOCs. Key classes of chemicals quantified using evacuated canisters included both alcohols and ketones, while sorbent tube samples included volatile fatty acids and ketones. The top five compounds made up close to 70% of VOCs and included: 1) acetic acid (830.1 μg m -3); 2) 2,3-butanedione (680.6 μg m -3); 3) methanol (195.8 μg m -3); 4) acetone (104.6 μg m -3); and 5) ethanol (101.9 μg m -3). Location variations for top five compounds averaged 49.5% in each section of the building and averaged 87% for the entire building.

  13. Global inventory of volatile organic compound emissions from anthropogenic sources

    SciTech Connect

    Piccot, S.D.; Watson, J.J.; Jones, J.W.

    1992-01-01

    The paper discusses the development of a global inventory of anthropogenic volatile organic compound (VOC) emissions. It includes VOC estimates for seven classes of VOCs: paraffins, olefins, aromatics (benzene, toluene, xylene), formaldehyde, other aldehydes, other aromatics, and marginally reactive compounds. These classes represent general classes of VOC compounds that possess different chemical reactivities in the atmosphere. The inventory shows total global anthropogenic VOC emissions of about 110,000 Gg/yr, about 10% lower than global VOC inventories developed by other researchers. The study identifies the U.S. as the largest emitter (21% of the total global VOC), followed by the USSR, China, India, and Japan. Globally, fuel wood combustion and savanna burning were among the largest VOC emission sources, accounting for over 35% of the total global VOC emissions. The production and use of gasoline, refuse disposal activities, and organic chemical and rubber manufacturing were also found to be significant sources of global VOC emissions.

  14. Volatile organic compound emissions from Larrea tridentata (creosotebush)

    NASA Astrophysics Data System (ADS)

    Jardine, K.; Abrell, L.; Kurc, S. A.; Huxman, T.; Ortega, J.; Guenther, A.

    2010-12-01

    We present results from the CREosote ATmosphere Interactions through Volatile Emissions (CREATIVE 2009) field study in southern Arizona aimed at quantifying emission rates of VOCs from creosotebush (Larrea tridentata) during the summer 2009 monsoon season. This species was chosen because of its vast distribution in North and South American deserts and because its resins have been reported to contain a rich set of volatile organic compounds (VOC). While a variety of ecosystems have been investigated for VOC emissions, deserts remain essentially unstudied, partially because of their low biomass densities and water limitations. However, during the North American monsoon, a pronounced increase in rainfall from an extremely dry June (<5 mm precipitation) to a rainy July (>80 mm) occurs over large areas of the Sonoran desert in the southwestern United States and northwestern Mexico. We observed a strong diurnal pattern of branch emissions and ambient concentrations of an extensive suite of VOCs with maxima in early afternoon. These include VOCs typically observed in forest sites (oxygenated VOCs and volatile isoprenoids) as well as a large number of other compounds, some of which have not been previously described from any plant including 1-chloro-2-methoxy-benzene and isobutyronitrile. Although generally considered to be derived from anthropogenic sources, we observed emissions of aromatic compounds including benzene, and a broad range of phenolics. Dimethyl sulfide emissions from creosotebush were higher than reported from any previously studied plant suggesting that terrestrial ecosystems should be reconsidered as an important source of this climatically important gas. We also present direct, primary emission measurements of isoprene and its apparent oxidation products methyl vinyl ketone, methacrolein, and 3-methyl furan (the later three compounds are typically assumed to form from secondary reactions within the atmosphere), as well as a group of compounds considered

  15. Volatile organic compound emissions from Larrea tridentata (creosotebush)

    NASA Astrophysics Data System (ADS)

    Jardine, K.; Abrell, L.; Kurc, S. A.; Huxman, T.; Ortega, J.; Guenther, A.

    2010-07-01

    The emission of Volatile Organic Compounds (VOCs) from plants impacts both climate and air quality by fueling atmospheric chemistry and by contributing to aerosol particles. While a variety of ecosystems have been investigated for VOC emissions, deserts remain essentially unstudied, partially because of their low biomass densities and water limitations. However, during the North American monsoon, a pronounced increase in rainfall from an extremely dry June (<5 mm precipitation) to a rainy July (>80 mm) occurs over large areas of the Sonoran desert in the Southwestern United States and Northwestern Mexico. We present results from the CREosote ATmosphere Interactions through Volatile Emissions (CREATIVE 2009) field study in Southern Arizona aimed at quantifying emission rates of VOCs from creosotebush (Larrea tridentata) during the summer 2009 monsoon season. This species was chosen because of its vast distribution in North and South American deserts and because its resins have been reported to contain a rich set of VOCs. We observed a strong diurnal pattern with branch emissions and ambient concentrations of an extensive suite of VOCs with maxima in early afternoon. These include VOCs typically observed in forest sites (oxygenated VOCs and volatile isoprenoids) as well as a large number of other compounds, some of which have not been previously described from any plant including 1-chloro-2-methoxy-benzene and isobutyronitrile. Although generally considered to be derived from anthropogenic sources, we observed emissions of aromatic compounds including benzene, and a broad range of phenolics. Dimethyl sulfide emissions from creosotebush were higher than reported from any previously studied plant suggesting that terrestrial ecosystems should be reconsidered as an important source of this climatically important gas. We also present direct, primary emission measurements of isoprene and its apparent oxidation products methyl vinyl ketone, methacrolein, and 3-methyl furan

  16. Electronic nose to detect volatile compound profile and quality changes in 'spring Belle' peach (Prunus persica L.) during cold storage in relation to fruit optical properties measured by time-resolved reflectance spectroscopy.

    PubMed

    Rizzolo, Anna; Bianchi, Giulia; Vanoli, Maristella; Lurie, Susan; Spinelli, Lorenzo; Torricelli, Alessandro

    2013-02-27

    The aim of this research was to study the relationships between electronic nose (E-nose) pattern, maturity class of peaches assessed at harvest by means of absorption coefficient at 670 nm (μ(a)670) measured in fruit pulp by time-resolved reflectance spectroscopy (TRS), and quality evolution during a 4 week cold storage. 'Spring Belle' peaches were measured for μ(a)670 by TRS, ranked according to decreasing μ(a)670 value, divided into three TRS maturity classes (less (LeM), medium (MeM), and more (MoM) mature), and randomized into 9 samples of 30 fruit each, so that fruits from the whole μ(a)670 range were present in each sample. At harvest and after 1, 2, 3, and 4 weeks of storage at 0 and 4 °C, fruits of each sample were evaluated for firmness, expressible juice, μ(a)670, and ethylene production. LeM and MoM peaches of each sample were analyzed for aroma pattern by a commercial electronic nose and by static HS-GC and for sugar (glucose, fructose, sucrose, and sorbitol) and organic acid (quinic, malic, and citric acids) compositions by HPLC. Principal component analysis (PCA) of electronic nose data emphasized the ability of the E-nose to assess the ripening stage of fruit associated with maturity class, storage time, and storage temperature. The sensors having the highest influence on the pattern were W5S in PC-1, W1S in PC-2, and W2S in PC-3. From linear correlation analysis between PCs and firmness, flavor, and volatile compounds, it was found that PC-1 was related to ethylene production and volatile compounds (mainly acetate esters and ethanol); the highest PC-1 scores were found for fruit belonging to the MoM class after 2 weeks of storage at 4 °C, which showed the rise in ethylene production coupled with the highest total volatile production and sugar and acid composition of ripe peach fruits. PC-2 correlated with hexanal, ethyl acetate, and sugar composition, and PC-3 was mainly related to flavor compounds; both functions significantly changed with

  17. 78 FR 24990 - Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound Emission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-29

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound...), several volatile organic compound (VOC) rules that were submitted by the Ohio Environmental Protection... emissions from stationary sources, storage of volatile organic liquids, industrial cleaning solvents,...

  18. Apple fruit volatile compound dynamics during storage in low O2 or high CO2 atmospheres

    USDA-ARS?s Scientific Manuscript database

    Long term controlled atmosphere (CA) storage of apples prolongs postharvest life and impacts fruit volatile compound production after fruit are removed from storage. As less is known regarding fruit volatile dynamics during storage, studies were conducted to characterize volatile compounds present ...

  19. Transport, behavior, and fate of volatile organic compounds in streams

    USGS Publications Warehouse

    Rathbun, R.E.

    2000-01-01

    Volatile organic compounds (VOCs) are compounds with chemical and physical properties that allow the compounds to move freely between the water and air phases of the environment. VOCs are widespread in the environment because of this mobility. Many VOCs have properties that make them suspected or known hazards to the health of humans and aquatic organisms. Consequently, understanding the processes affecting the concentration and distribution of VOCs in the environment is necessary. The transport, behavior, and fate of VOCs in streams are determined by combinations of chemical, physical, and biological processes. These processes are volatilization, absorption, wet and dry deposition, microbial degradation, sorption, hydrolysis, aquatic photolysis, oxidation, chemical reaction, biocon-centration, advection, and dispersion. The relative importance of each of these processes depends on the characteristics of the VOC and the stream. The U.S. Geological Survey National Water-Quality Assessment Program selected 55 VOCs for study. This article reviews the characteristics of the various processes that could affect the transport, behavior, and fate of these VOCs in streams.

  20. Emission characteristics of volatile compounds during sludges drying process.

    PubMed

    Deng, Wen-Yi; Yan, Jian-Hua; Li, Xiao-Dong; Wang, Fei; Zhu, Xiao-Wan; Lu, Sheng-Yong; Cen, Ke-Fa

    2009-02-15

    The emission characteristics of volatile compounds (VCs) during municipal sewage sludge (MSS) and paper mill sludge (PMS) drying process were investigated through experiments conducted on a lab-scale tubular drying furnace and a pilot-scale paddle dryer, respectively. The result indicated that five kinds of VCs, i.e. CO(2), NH(3), C(7)H(16) (n-heptane), volatile fatty acids (VFAs) and CH(4) were emitted during the drying process. It was found that the NH(3) and CO(2) were the primary compound released from the MSS drying process. In the case of the PMS, the VFAs and CO(2) were the main compounds released. The temperature and water content of sludge had great effects on the emission rates of NH(3), C(7)H(16), CO(2) and VFAs. The pH and chemical oxygen demand (COD) of condensate from the paddle dryer were also studied. It showed that pH and COD of condensate from MSS were much higher than that from the PMS, and that the higher COD value of the MSS condensate interrelated to the higher ammonium and sulfur content of it.

  1. Volatile organic compounds in the unsaturated zone from radioactive wastes

    USGS Publications Warehouse

    Baker, Ronald J.; Andraski, Brian J.; Stonestrom, David A.; Luo, Wentai

    2012-01-01

    Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0–2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m-2 yr-1. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere.

  2. Volatile organic compounds in the unsaturated zone from radioactive wastes.

    PubMed

    Baker, Ronald J; Andraski, Brian J; Stonestrom, David A; Luo, Wentai

    2012-01-01

    Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0-2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m yr. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere.

  3. Changes on physico-chemical properties, lipid oxidation and volatile compounds during the manufacture of celta dry-cured loin.

    PubMed

    Pateiro, M; Franco, D; Carril, J A; Lorenzo, J M

    2015-08-01

    The present study deals with the changes on the main technological characteristics and volatile compounds profile of a traditional Spanish dry-ripened loin from Celta pig breed. The evolution of physicochemical properties, colour, texture, free fatty acid profile and volatile compounds were assessed throughout the process seasoning, post-seasoning and after 30 and 60 days of dry-ripening. As it was expected, pH, moisture and activity water were significantly (P < 0.001) influenced by ripening time. Statistical analysis also displayed that colour parameters (lightness, L*; redness, a*; yellowness, b*) decreased significantly (P < 0.001) during the manufacturing process. On the other hand, lipid oxidation reached the highest levels at the end of process with mean values of 0.34 mg MDA/kg. Regarding total FFA, a significant (P < 0.001) increase was observed during the manufacturing process, being MUFA the most abundant at the end of process. Finally, sixty seven volatile compounds were identified during the manufacture of Celta dry-cured loin. At the end of process, volatile compounds from microbial activity were the most abundant followed by volatile compounds from lipid oxidation.

  4. Airborne flux measurements of biogenic volatile organic compounds over California

    NASA Astrophysics Data System (ADS)

    Misztal, P. K.; Karl, T.; Weber, R.; Jonsson, H. H.; Guenther, A. B.; Goldstein, A. H.

    2014-03-01

    Biogenic Volatile Organic Compound (BVOC) fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne BVOC Emission Research in Natural Ecosystem Transects (CABERNET) campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC) approach used measurements from a PTR-MS and a wind radome probe to directly determine fluxes of isoprene, MVK + MAC, methanol, monoterpenes, and MBO over ∼10 000 km of flight paths focusing on areas of California predicted to have the largest emissions of isoprene. The Fast Fourier Transform (FFT) approach was used to calculate fluxes over long transects of more than 15 km, most commonly between 50 and 150 km. The Continuous Wavelet Transformation (CWT) approach was used over the same transects to also calculate "instantaneous" fluxes with localization of both frequency and time independent of non-stationarities. Vertical flux divergence of isoprene is expected due to its relatively short lifetime and was measured directly using "racetrack" profiles at multiple altitudes. It was found to be linear and in the range 5% to 30% depending on the ratio of aircraft altitude to PBL height (z / zi). Fluxes were generally measured by flying consistently at 400 ± 50 m (a.g.l.) altitude, and extrapolated to the surface according to the determined flux divergence. The wavelet-derived surface fluxes of isoprene averaged to 2 km spatial resolution showed good correspondence to Basal Emission Factor (BEF) landcover datasets used to drive biogenic VOC (BVOC) emission models. The surface flux of isoprene was close to zero over Central Valley crops and desert shrublands, but was very high (up to 15 mg m-2 h-1) above oak woodlands, with clear dependence of emissions on temperature and oak density. Isoprene concentrations of up to 8 ppb were observed at aircraft height on the hottest days and over the dominant source regions. While isoprene emissions from agricultural crop regions, shrublands, and

  5. Diffusive transport of volatile organic compounds through geomembranes

    NASA Astrophysics Data System (ADS)

    McWatters, Rebecca Sheila

    The diffusive transport of volatile organic compounds (VOCs) through geomembranes is examined. The key diffusive parameters: diffusion ( Dg), partitioning (Sgf) and permeation (Pg) coefficients, for transport from both vapour and aqueous phases are evaluated. Consideration is given to different types of geomembrane, exposure to cold climatic conditions, and aged geomembranes exhumed after 3 and 25 years. Laboratory sorption and diffusion tests are performed and modeling is used to infer diffusive parameters from experimental data. The transport of VOCs through polyvinyl chloride (PVC) and linear low-density polyethylene (LLDPE) geomembranes from both aqueous and vapour phases is evaluated by Purge & Trap-GC/MS. Results indicate that VOC transport through geomembranes in a simulated landfill environment is identical despite the phase they originate from. Subsequently, this finding is confirmed by examining diffusion of vapour-phase VOCs using Solid Phase Microextraction-GC/FID. Diffusive transport of VOCs through traditional PVC, LLDPE and high-density polyethylene (HDPE) geomembranes is compared with that through two novel co-extruded geomembranes, one with a polyamide inner core, the other an ethylene vinyl alcohol (EVOH) inner core. Both co-extruded geomembranes show a 10-200-fold decrease in Pg values and therefore improved diffusive resistance to VOCs compared to the traditional geomembranes. EVOH also shows a 5-12-fold decrease in Pg values compared to an HDPE geomembrane. The effects of cold environments on the diffusion of VOCs are studied. Five geomembranes are exposed to simulated cold climatic conditions in the laboratory. Results from diffusion tests run at 2-24°C indicate Dg and Pg decrease with temperature. The temperature and diffusion coefficients relationship follow the Arrhenius equation. Activation energies of diffusion are calculated specific to each geomembrane and contaminant. An HPDE geomembrane taken from a field site in the Canadian Arctic

  6. An indirect assay for volatile compound production in yeast strains

    PubMed Central

    Ravasio, Davide; Walther, Andrea; Trost, Kajetan; Vrhovsek, Urska; Wendland, Jürgen

    2014-01-01

    Traditional flavor analysis relies on gas chromatography coupled to mass spectrometry (GC-MS) methods. Here we describe an indirect method coupling volatile compound formation to an ARO9-promoter-LacZ reporter gene. The resulting β-galactosidase activity correlated well with headspace solid phase micro extraction (HS/SPME) GC-MS data, particularly with respect to the formation of rose flavor. This tool enables large-scale screening of yeast strains and their progeny to identify the most flavor active strains. PMID:24424137

  7. Helium discharge detector for quantitation of volatile organohalogen compounds

    SciTech Connect

    Ryan, D.A.; Argentine, S.M.; Rice, G.W. )

    1990-04-15

    A helium discharge has been evaluated as an element-selective, gas chromatographic detector for volatile organohalogen compounds. Absolute limits of detection ranged from 3 pg for chloroform to 29 pg for p-dibromobenzene with a linear response of 10(3)-10(4). The relative response of the detector was determined to be based solely on the mass of the halogen species present. This feature allowed for relatively simple quantitation of chlorinated and brominated haloform species in water samples by the addition of a single internal standard for calibration of the halogen response.

  8. Biocide effects of volatile organic compounds produced by potential biocontrol rhizobacteria on Sclerotinia sclerotiorum

    PubMed Central

    Giorgio, Annalisa; De Stradis, Angelo; Lo Cantore, Pietro; Iacobellis, Nicola S.

    2015-01-01

    Six rhizobacteria isolated from common bean and able to protect bean plants from the common bacterial blight (CBB) causal agent, were in vitro evaluated for their potential antifungal effects toward different plant pathogenic fungi, mostly soil-borne. By dual culture assays, the above bacteria resulted producing diffusible and volatile metabolites which inhibited the growth of the majority of the pathogens under study. In particular, the latter substances highly affected the mycelium growth of Sclerotinia sclerotiorum strains, one of which was selected for further studies either on mycelium or sclerotia. Gas chromatographic analysis of the bacterial volatiles led to the identification of an array of volatile organic compounds (VOCs). Time course studies showed the modification of the VOCs profile along a period of 5 days. In order to evaluate the single detected VOC effects on fungal growth, some of the pure compounds were tested on S. sclerotiorum mycelium and their minimal inhibitory quantities were determined. Similarly, the minimal inhibitory quantities on sclerotia germination were also defined. Moreover, observations by light and transmission electron microscopes highlighted hyphae cytoplasm granulation and ultrastructural alterations at cell organelles, mostly membranes, mitochondria, and endoplasmic reticulum. The membranes appeared one of the primary targets of bacterial volatiles, as confirmed by hemolytic activity observed for the majority of pure VOCs. However, of interest is the alteration observed on mitochondria as well. PMID:26500617

  9. Biocide effects of volatile organic compounds produced by potential biocontrol rhizobacteria on Sclerotinia sclerotiorum.

    PubMed

    Giorgio, Annalisa; De Stradis, Angelo; Lo Cantore, Pietro; Iacobellis, Nicola S

    2015-01-01

    Six rhizobacteria isolated from common bean and able to protect bean plants from the common bacterial blight (CBB) causal agent, were in vitro evaluated for their potential antifungal effects toward different plant pathogenic fungi, mostly soil-borne. By dual culture assays, the above bacteria resulted producing diffusible and volatile metabolites which inhibited the growth of the majority of the pathogens under study. In particular, the latter substances highly affected the mycelium growth of Sclerotinia sclerotiorum strains, one of which was selected for further studies either on mycelium or sclerotia. Gas chromatographic analysis of the bacterial volatiles led to the identification of an array of volatile organic compounds (VOCs). Time course studies showed the modification of the VOCs profile along a period of 5 days. In order to evaluate the single detected VOC effects on fungal growth, some of the pure compounds were tested on S. sclerotiorum mycelium and their minimal inhibitory quantities were determined. Similarly, the minimal inhibitory quantities on sclerotia germination were also defined. Moreover, observations by light and transmission electron microscopes highlighted hyphae cytoplasm granulation and ultrastructural alterations at cell organelles, mostly membranes, mitochondria, and endoplasmic reticulum. The membranes appeared one of the primary targets of bacterial volatiles, as confirmed by hemolytic activity observed for the majority of pure VOCs. However, of interest is the alteration observed on mitochondria as well.

  10. Multisorbent tubes for collecting volatile organic compounds in spacecraft air

    NASA Technical Reports Server (NTRS)

    Matney, M. L.; Beck, S. W.; Limero, T. F.; James, J. T.

    2000-01-01

    The sampling capability of Tenax-TA tubes, used in the National Aeronautics and Space Administration's solid sorbent air sampler to trap and concentrate contaminants from air aboard spacecraft, was improved by incorporating two sorbents within the tubes. Existing tubes containing only Tenax-TA allowed highly volatile compounds to "break through" during collection of a 1.5 L air sample. First the carbon molecular sieve-type sorbents Carboxen 569 and Carbosieve S-III were tested for their ability to quantitatively trap the highly volatile compounds. Breakthrough volumes were determined with the direct method, whereby low ppm levels of methanol or Freon 12 in nitrogen were flowed through the sorbent tubes at 30 mL/min, and breakthrough was detected by gas chromatography. Breakthrough volumes for methanol were about 9 L/g on Carboxen 569 and 11 L/g on Carbosieve S-III; breakthrough volumes for Freon 12 were about 7 L/g on Carboxen 569 and > 26 L/g on Carbosieve S-III. Next, dual-bed tubes containing either Tenax-TA/Carbosieve S-III, Tenax-TA/Carboxen 569, or Carbotrap/Carboxen 569 to a 10-component gas mixture were exposed, in dry and in humidified air (50% relative humidity), and percentage recoveries of each compound were determined. The Tenax-TA/Carboxen 569 combination gave the best overall recoveries (75-114% for the 10 compounds). Acetaldehyde had the lowest recovery (75%) of the 10 compounds, but this value was still an improvement over either the other two sorbent combinations or the original single-sorbent tubes.

  11. Multisorbent tubes for collecting volatile organic compounds in spacecraft air

    NASA Technical Reports Server (NTRS)

    Matney, M. L.; Beck, S. W.; Limero, T. F.; James, J. T.

    2000-01-01

    The sampling capability of Tenax-TA tubes, used in the National Aeronautics and Space Administration's solid sorbent air sampler to trap and concentrate contaminants from air aboard spacecraft, was improved by incorporating two sorbents within the tubes. Existing tubes containing only Tenax-TA allowed highly volatile compounds to "break through" during collection of a 1.5 L air sample. First the carbon molecular sieve-type sorbents Carboxen 569 and Carbosieve S-III were tested for their ability to quantitatively trap the highly volatile compounds. Breakthrough volumes were determined with the direct method, whereby low ppm levels of methanol or Freon 12 in nitrogen were flowed through the sorbent tubes at 30 mL/min, and breakthrough was detected by gas chromatography. Breakthrough volumes for methanol were about 9 L/g on Carboxen 569 and 11 L/g on Carbosieve S-III; breakthrough volumes for Freon 12 were about 7 L/g on Carboxen 569 and > 26 L/g on Carbosieve S-III. Next, dual-bed tubes containing either Tenax-TA/Carbosieve S-III, Tenax-TA/Carboxen 569, or Carbotrap/Carboxen 569 to a 10-component gas mixture were exposed, in dry and in humidified air (50% relative humidity), and percentage recoveries of each compound were determined. The Tenax-TA/Carboxen 569 combination gave the best overall recoveries (75-114% for the 10 compounds). Acetaldehyde had the lowest recovery (75%) of the 10 compounds, but this value was still an improvement over either the other two sorbent combinations or the original single-sorbent tubes.

  12. Multisorbent tubes for collecting volatile organic compounds in spacecraft air.

    PubMed

    Matney, M L; Beck, S W; Limero, T F; James, J T

    2000-01-01

    The sampling capability of Tenax-TA tubes, used in the National Aeronautics and Space Administration's solid sorbent air sampler to trap and concentrate contaminants from air aboard spacecraft, was improved by incorporating two sorbents within the tubes. Existing tubes containing only Tenax-TA allowed highly volatile compounds to "break through" during collection of a 1.5 L air sample. First the carbon molecular sieve-type sorbents Carboxen 569 and Carbosieve S-III were tested for their ability to quantitatively trap the highly volatile compounds. Breakthrough volumes were determined with the direct method, whereby low ppm levels of methanol or Freon 12 in nitrogen were flowed through the sorbent tubes at 30 mL/min, and breakthrough was detected by gas chromatography. Breakthrough volumes for methanol were about 9 L/g on Carboxen 569 and 11 L/g on Carbosieve S-III; breakthrough volumes for Freon 12 were about 7 L/g on Carboxen 569 and > 26 L/g on Carbosieve S-III. Next, dual-bed tubes containing either Tenax-TA/Carbosieve S-III, Tenax-TA/Carboxen 569, or Carbotrap/Carboxen 569 to a 10-component gas mixture were exposed, in dry and in humidified air (50% relative humidity), and percentage recoveries of each compound were determined. The Tenax-TA/Carboxen 569 combination gave the best overall recoveries (75-114% for the 10 compounds). Acetaldehyde had the lowest recovery (75%) of the 10 compounds, but this value was still an improvement over either the other two sorbent combinations or the original single-sorbent tubes.

  13. Volatile compound diversity and conserved alarm behaviour in Triatoma dimidiata.

    PubMed

    May-Concha, Irving; Rojas, Julio C; Cruz-López, Leopoldo; Ibarra-Cerdeña, Carlos N; Ramsey, Janine M

    2015-02-06

    Triatoma dimidiata (Latreille) is a key vector complex of Trypanosoma cruzi, etiologic agent of Chagas disease, as it spans North, Central, and South America. Although morphological and genetic studies clearly indicate existence of at least five clades within the species, there has been no robust or systematic revision, or appropriate nomenclature change for species within the complex. Three of the clades (haplogroups) are distributed in Mexico, and recent evidence attests to dispersal of clades across previously "presumed" monotypic geographic regions. Evidence of niche conservatism among sister species of this complex suggests that geographic dispersal is possible for non-sympatric populations, although no information is available on the behavioural aspects of potential interclade interactions, for instance whether differentiation of chemical signaling or response to these signals could impede communication among the haplogroups. Volatiles emitted by disturbed bugs, Brindley's (BGs), and metasternal (MGs) glands were identified using solid-phase micro-extraction (SPME) and gas chromatography coupled mass spectrometry (GC-MS). Volatile compounds emitted by BGs and MGs, and those secreted by disturbed nymphs and adults, of the three Mexican T. dimidiata haplogroups were tested for avoidance behaviour by conspecific nymphs and adults using an olfactometer. Triatoma dimidiata haplogroups all have three age-related alarm responses: absence of response by early stage nymphs, stage-specific response by 4-5th stage nymphs, and a shared 4-5th nymph and adult response to adult compounds. Disturbed bugs released 15 to 24 compounds depending on the haplogroup, among which were three pyrazines, the first report of these organoleptics in Triatominae. Isobutyric acid from BGs was the most abundant molecule in the response in all haplogroups, in addition to 15 (h1) to 21 (h2 and h3) MG compounds. Avoidance behaviour of disturbed bugs and volatiles emitted by BGs were haplogroup

  14. Emission of volatile organic compounds from silage: compounds, sources, and implications

    USDA-ARS?s Scientific Manuscript database

    Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) emitted to the atmosphere. A small number of studies have measured VOC emission from silage, but not enough is known about the processes involved to accurately quantify emission r...

  15. Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

    NASA Astrophysics Data System (ADS)

    Cross, E. S.; Hunter, J. F.; Carrasquillo, A. J.; Franklin, J. P.; Herndon, S. C.; Jayne, J. T.; Worsnop, D. R.; Miake-Lye, R. C.; Kroll, J. H.

    2013-03-01

    A detailed understanding of the climate and air quality impacts of aviation requires detailed measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) from aircraft. Currently both the amount and chemical composition of aircraft I/SVOC emissions remain poorly characterized. Here we characterize I/SVOC emissions from aircraft, using a novel instrument for the online, quantitative measurement of the mass loading and composition of low-volatility organic vapors. Emissions from the NASA DC8 aircraft were sampled on the ground, 143 m downwind of the engines and characterized as a function of engine power from ground idle (~4% maximum rated thrust) through 85% power. Results show that I/SVOC emissions are highest during engine-idle operating conditions, with decreasing but non-zero I/SVOC emissions at higher engine powers. Comparison of I/SVOC emissions with total hydrocarbon (THC) measurements, VOC measurements, and an established emissions profile indicates that I/SVOCs comprise 10-20% of the total organic gas phase emissions at idle, and an increasing fraction of the total gas phase organic emissions at higher powers. Positive matrix factorization of online mass spectra is used to identify three distinct types of I/SVOC emissions: aliphatic, aromatic and oxygenated. The volatility and chemical composition of the emissions suggest that unburned fuel is the dominant source of I/SVOCs at idle, while pyrolysis products make up an increasing fraction of the I/SVOCs at higher powers. Oxygenated I/SVOC emissions were detected at lower engine powers (≤30%) and may be linked to cracked, partially oxidized or unburned fuel components.

  16. Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

    NASA Astrophysics Data System (ADS)

    Cross, E. S.; Hunter, J. F.; Carrasquillo, A. J.; Franklin, J. P.; Herndon, S. C.; Jayne, J. T.; Worsnop, D. R.; Miake-Lye, R. C.; Kroll, J. H.

    2013-08-01

    A detailed understanding of the climate and air quality impacts of aviation requires measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) from aircraft. Currently both the amount and chemical composition of aircraft I/SVOC emissions remain poorly characterized. Here we characterize I/SVOC emissions from aircraft, using a novel instrument for the online, quantitative measurement of the mass loading and composition of low-volatility organic vapors. Emissions from the NASA DC8 aircraft were sampled on the ground 143 m downwind of the engines and characterized as a function of engine power from idle (4% maximum rated thrust) through 85% power. Results show that I/SVOC emissions are highest during engine idle operating conditions, with decreasing but non-zero I/SVOC emissions at higher engine powers. Comparison of I/SVOC emissions with total hydrocarbon (THC) measurements, VOC measurements, and an established emissions profile indicates that I/SVOCs comprise 10-20% of the total organic gas-phase emissions at idle, and an increasing fraction of the total gas-phase organic emissions at higher powers. Positive matrix factorization of online mass spectra is used to identify three distinct types of I/SVOC emissions: aliphatic, aromatic and oxygenated. The volatility and chemical composition of the emissions suggest that unburned fuel is the dominant source of I/SVOCs at idle, while pyrolysis products make up an increasing fraction of the I/SVOCs at higher powers. Oxygenated I/SVOC emissions were detected at lower engine powers (≤30%) and may be linked to cracked, partially oxidized or unburned fuel components.

  17. Formation of highly oxidized multifunctional organic compounds from anthropogenic volatile organic compounds

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Recent studies have shown that highly oxidized multifunctional organic compounds (HOMs) from biogenic volatile organic compounds are important for new particle formation and early particle growth (e.g., Ehn et al., 2014). The formation mechanism has extensively been studied for biogenic precursors like alpha-pinene and was shown to proceed through an initial reaction with either OH radicals or ozone followed by radical propagation in a mechanism that involves O2 attack and hydrogen abstraction (Crounse et al., 2013). While the same processes can be expected for anthropogenic volatile organic compounds (AVOC), few studies have investigated these so far. Here we present the formation of HOMs from a variety of aromatic compounds after reaction with OH. All the compounds analyzed show HOM formation. AVOC could therefore play an important role in new particle formation events that have been detected in urban areas. References Crounse, J.D. et al., Autoxidation of organic compounds in the atmosphere. J. Phys.Chem. Lett. 4, 3513-3520 (2013). Ehn, M., et al. A large source of low-volatility secondary organic aerosol, Nature 506, 476-479 (2014).

  18. 75 FR 57412 - Approval and Promulgation of Implementation Plans Alabama: Volatile Organic Compounds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Approval and Promulgation of Implementation Plans Alabama: Volatile Organic... ``volatile organic compounds'' (VOCs) found at Alabama Administrative Code section...

  19. SOURCE APPORTIONMENT OF EXPOSURES TO VOLATILE ORGANIC COMPOUNDS: I. EVALUATION OF RECEPTOR MODELS USING SIMULATED EXPOSURE DATA. (R826788)

    EPA Science Inventory

    Four receptor-oriented source apportionment models were evaluated by applying them to simulated personal exposure data for select volatile organic compounds (VOCs) that were generated by Monte Carlo sampling from known source contributions and profiles. The exposure sources mo...

  20. Volatile compounds of raspberry fruit: from analytical methods to biological role and sensory impact.

    PubMed

    Aprea, Eugenio; Biasioli, Franco; Gasperi, Flavia

    2015-01-30

    Volatile compounds play a key role in the formation of the well-recognized and widely appreciated raspberry aroma. Studies on the isolation and identification of volatile compounds in raspberry fruit (Rubus idaeus L.) are reviewed with a focus on aroma-related compounds. A table is drawn up containing a comprehensive list of the volatile compounds identified so far in raspberry along with main references and quantitative data where available. Two additional tables report the glycosidic bond and enantiomeric distributions of the volatile compounds investigated up to now in raspberry fruit. Studies on the development and evolution of volatile compounds during fruit formation, ripening and senescence, and genetic and environmental influences are also reviewed. Recent investigations showing the potential role of raspberry volatile compounds in cultivar differentiation and fruit resistance to mold disease are reported as well. Finally a summary of research done so far and our vision for future research lines are reported.

  1. Identification and Quantification of Volatile Organic Compounds at a Dairy

    NASA Astrophysics Data System (ADS)

    Filipy, J.; Mount, G.; Westberg, H.; Rumburg, B.

    2003-12-01

    Livestock operations in the United States are an escalating environmental concern. The increasing density of livestock within a farm results in an increased emission of odorous gases, which have gained considerable attention by the public in recent years (National Research Council (NRC), 2002). Odorous compounds such as ammonia (NH3), volatile organic compounds (VOC's), and hydrogen sulfide (H2S) were reported to have a major effect on the quality of life of local residents living near livestock facilities (NRC, 2002). There has been little data collected related to identification and quantification of gaseous compounds collected from open stall dairy operations in the United States. The research to be presented identifies and quantifies VOCs produced from a dairy operation that contribute to odor and other air quality problems. Many different VOCs were identified in the air downwind of an open lactating cow stall area and near a waste lagoon at the Washington State University dairy using Gas Chromatography Mass Spectroscopy (GC-MS) analysis techniques. Identified compounds were very diverse and included many alcohols, aldehydes, amines, aromatics, esters, ethers, a fixed gas, halogenated hydrocarbons, hydrocarbons, ketones, other nitrogen containing compounds, sulfur containing compounds, and terpenes. The VOCs directly associated with cattle waste were dependent on ambient temperature, with the highest emissions produced during the summer months. Low to moderate wind speeds were ideal for VOC collection. Concentrations of quantified compounds were mostly below odor detection thresholds found in the literature, however the combined odor magnitude of the large number of compounds detected was most likely above any minimum detection threshold.

  2. Photocatalytic destruction of volatile organic compounds in water. Master's thesis

    SciTech Connect

    Oluic, S.

    1991-12-10

    Ground water at the Anniston Army Depot in Anniston, Alabama has been found to be contaminated with volatile organic compounds. Recent research has indicated that advanced oxidation processes, namely hydrogen peroxide catalyzed by ultraviolet light radiation, can be successful in destroying these contaminants. In this process hydrogen peroxide is decomposed by ultraviolet radiation producing hydroxyl free radicals which in turn oxidize the organic compounds present. A series of batch tests and flow through experiments using this oxidation process was performed on a synthetic wastewater that closely duplicated contaminant concentration levels found at Anniston. These contaminants, 1,2 dichloroethene, trichloroethene, dichloromethane and benzene, were found readily destructed by the UV/H2O2 process both individually and in mixtures during batch testing and in flow-through experiments. All experimentation was performed utilizing a thin film reactor.

  3. Volatile compounds in fruits of Peucedanum cervaria (Lap.) L.

    PubMed

    Skalicka-Wozniak, Krystyna; Los, Renata; Glowniak, Kazimierz; Malm, Anna

    2009-07-01

    The volatile compounds from Peucedanum cervaria (Lap.) L. were obtained by hydrodistillation (HD) and headspace solid-phase microextraction techniques (HS-SPME), and then analyzed by GC/MS methods. The composition of samples from a botanical garden was compared with plants collected in the wild. The main compounds of the essential oils of P. cervaria were identified as alpha-pinene, sabinene, and beta-pinene (more than 80% of oil). The content of beta-myrcene, limonene+beta-phellandrene, and germacrene D was higher than 1%. The in vitro antibacterial activity of the essential oil was evaluated by the agar dilution method against ten reference strains of Gram-positive and Gram-negative bacteria.

  4. Oceanic Emissions and Atmospheric Depositions of Volatile Organic Compounds

    NASA Astrophysics Data System (ADS)

    Yang, M.; Blomquist, B.; Beale, R.; Nightingale, P. D.; Liss, P. S.

    2015-12-01

    Atmospheric volatile organic compounds (VOCs) affect the tropospheric oxidative capacity due to their ubiquitous abundance and relatively high reactivity towards the hydroxyal radical. Over the ocean and away from terrestrial emission sources, oxygenated volatile organic compounds (OVOCs) make up a large fraction of VOCs as airmasses age and become more oxidized. In addition to being produced or destroyed in the marine atmosphere, OVOCs can also be emitted from or deposited to the surface ocean. Here we first present direct air-sea flux measurements of three of the most abundant OVOCs - methanol, acetone, and acetaldehyde, by the eddy covariance technique from two cruises in the Atlantic: the Atlantic Meridional Transect in 2012 and the High Wind Gas Exchange Study in 2013. The OVOC mixing ratios were quantified by a high resolution proton-reaction-transfer mass spectrometer with isotopically labeled standards and their air-sea (net) fluxes were derived from the eddy covariance technique. Net methanol flux was consistently from the atmosphere to the surface ocean, while acetone varied from supersaturation (emission) in the subtropics to undersaturation (deposition) in the higher latitudes of the North Atlantic. The net air-sea flux of acetaldehyde is near zero through out the Atlantic despite the apparent supersaturation of this compound in the surface ocean. Knowing the dissolved concentrations and in situ production rates of these compounds in seawater, we then estimate their bulk atmospheric depositions and oceanic emissions. Lastly, we summarize the state of knowledge on the air-sea transport of a number of organic gasses, and postulate the magnitude and environmental impact of total organic carbon transfer between the ocean and the atmosphere.

  5. Evaporation of volatile organic compounds from human skin in vitro.

    PubMed

    Gajjar, Rachna M; Miller, Matthew A; Kasting, Gerald B

    2013-08-01

    The specific evaporation rates of 21 volatile organic compounds (VOCs) from either human skin or a glass substrate mounted in modified Franz diffusion cells were determined gravimetrically. The diffusion cells were positioned either on a laboratory bench top or in a controlled position in a fume hood, simulating indoor and outdoor environments, respectively. A data set of 54 observations (34 skin and 20 glass) was assembled and subjected to a correlation analysis employing 5 evaporative mass transfer relationships drawn from the literature. Models developed by Nielsen et al. (Prediction of isothermal evaporation rates of pure volatile organic compounds in occupational environments: a theoretical approach based on laminar boundary layer theory. Ann Occup Hyg 1995;39:497-511.) and the U.S. Environmental Protection Agency (Peress, Estimate evaporative losses from spills. Chem Eng Prog 2003; April: 32-34.) were found to be the most effective at correlating observed and calculated evaporation rates under the various conditions. The U.S. EPA model was selected for further use based on its simplicity. This is a turbulent flow model based only on vapor pressure and molecular weight of the VOC and the effective air flow rate u. Optimum values of u for the two laboratory environments studied were 0.23 m s(-1) (bench top) and 0.92 m s(-1) (fume hood).

  6. Diagnosing gastrointestinal illnesses using fecal headspace volatile organic compounds

    PubMed Central

    Chan, Daniel K; Leggett, Cadman L; Wang, Kenneth K

    2016-01-01

    Volatile organic compounds (VOCs) emitted from stool are the components of the smell of stool representing the end products of microbial activity and metabolism that can be used to diagnose disease. Despite the abundance of hydrogen, carbon dioxide, and methane that have already been identified in human flatus, the small portion of trace gases making up the VOCs emitted from stool include organic acids, alcohols, esters, heterocyclic compounds, aldehydes, ketones, and alkanes, among others. These are the gases that vary among individuals in sickness and in health, in dietary changes, and in gut microbial activity. Electronic nose devices are analytical and pattern recognition platforms that can utilize mass spectrometry or electrochemical sensors to detect these VOCs in gas samples. When paired with machine-learning and pattern recognition algorithms, this can identify patterns of VOCs, and thus patterns of smell, that can be used to identify disease states. In this review, we provide a clinical background of VOC identification, electronic nose development, and review gastroenterology applications toward diagnosing disease by the volatile headspace analysis of stool. PMID:26819529

  7. Diagnosing gastrointestinal illnesses using fecal headspace volatile organic compounds.

    PubMed

    Chan, Daniel K; Leggett, Cadman L; Wang, Kenneth K

    2016-01-28

    Volatile organic compounds (VOCs) emitted from stool are the components of the smell of stool representing the end products of microbial activity and metabolism that can be used to diagnose disease. Despite the abundance of hydrogen, carbon dioxide, and methane that have already been identified in human flatus, the small portion of trace gases making up the VOCs emitted from stool include organic acids, alcohols, esters, heterocyclic compounds, aldehydes, ketones, and alkanes, among others. These are the gases that vary among individuals in sickness and in health, in dietary changes, and in gut microbial activity. Electronic nose devices are analytical and pattern recognition platforms that can utilize mass spectrometry or electrochemical sensors to detect these VOCs in gas samples. When paired with machine-learning and pattern recognition algorithms, this can identify patterns of VOCs, and thus patterns of smell, that can be used to identify disease states. In this review, we provide a clinical background of VOC identification, electronic nose development, and review gastroenterology applications toward diagnosing disease by the volatile headspace analysis of stool.

  8. Volatile profile, lipid oxidation and protein oxidation of irradiated ready-to-eat cured turkey meat products

    NASA Astrophysics Data System (ADS)

    Feng, Xi; Ahn, Dong Uk

    2016-10-01

    Irradiation had little effects on the thiobarbituric acid reactive substances (TBARS) values in ready-to-eat (RTE) turkey meat products, while it increased protein oxidation at 4.5 kGy. The volatile profile analyses indicated that the amount of sulfur compounds increased linearly as doses increased in RTE turkey meat products. By correlation analysis, a positive correlation was found between benzene/ benzene derivatives and alcohols with lipid oxidation, while aldehydes, ketones and alkane, alkenes and alkynes were positively correlated with protein oxidation. Principle component analysis showed that irradiated meat samples can be discriminated by two categories of volatile compounds: Strecker degradation products and radiolytic degradation products. The cluster analysis of volatile data demonstrated that low-dose irradiation had minor effects on the volatile profile of turkey sausages (<1.5 kGy). However, as the doses increased, the differences between the irradiated and non-irradiated cured turkey products became significant.

  9. Applicability of emanating volatile organic compounds from various forensic specimens for individual differentiation.

    PubMed

    Brown, Jessica S; Prada, Paola A; Curran, Allison M; Furton, Kenneth G

    2013-03-10

    Trace biological materials contain volatile profiles that have yet to be evaluated to determine their value in forensic investigations. The volatiles released by different biological specimens (hand odor, hair, fingernails and saliva) collected from twenty individuals were identified using a solid phase microextraction-gas chromatography-mass spectrometry method. The human scent compounds from each specimen, per subject, were evaluated using Spearman rank correlation to assess the applicability of these compounds for the differentiation of individuals. The volatile organic compounds from each specimen type were readily identified and discriminated. When conducting inter-subject discrimination within a single specimen type, greater than 98.9% of the samples, or individuals, were differentiated for all specimen types. When conducting inter-subject discrimination among the four specimen types 99.6% of the samples were differentiated, at the 0.9 correlation coefficient threshold. Additionally, the only occurrence of cross-correlation between specimen types was observed between hair and fingernails while there were no cross-correlations with hand odor or saliva thereby demonstrating the distinctiveness of these specimens.

  10. Comparison of the Profile and Composition of Volatiles in Coniferous Needles According to Extraction Methods.

    PubMed

    Jun, Yonjin; Lee, Sang Mi; Ju, Hyun Kyoung; Lee, Hong Jin; Choi, Hyung-Kyoon; Jo, Gyeong Suk; Kim, Young-Suk

    2016-03-17

    The enantiomeric distribution and profile of volatiles in plants, which affect the biological and organoleptic properties, can be varied depending on extraction methods as well as their cultivars. The secondary volatile components of the needles of three conifer cultivars (Chamaecyparispisifera, Chamaecyparisobtusa, and Thujaorientalis) were compared. Furthermore, the effects of three different extraction methods--solid-phase microextraction (SPME), steam distillation (SD), and solvent extraction (SE)--on the composition and enantiomeric distribution of those volatiles were elucidated. Monoterpene hydrocarbons predominated in all samples, and the compositions of sesquiterpenes and diterpenes differed according to the cultivar. In particular, the yields of oxygenated monoterpenes and sesquiterpenes were greatest for SD, whereas those of sesquiterpenes and diterpenes were highest for SE. On the other hand, more monoterpenes with higher volatility could be obtained with SPME and SD than when using SE. In addition, the enantiomeric composition of nine chiral compounds found in three cultivars differed according to their chemotype. There were also some differences in the yielded oxygenated monoterpenes and sesquiterpene hydrocarbons, but not monoterpene hydrocarbons, according to the extraction method. These results demonstrate that the extraction methods used as well as the cultivars influence the measured volatile profiles and enantiomeric distribution of coniferous needle extracts.

  11. 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

  12. Anti-Salmonella Activity of Volatile Compounds of Vietnam Coriander.

    PubMed

    Fujita, Ken-Ichi; Chavasiri, Warinthorn; Kubo, Isao

    2015-07-01

    Essential oil derived from the fresh leaves of Polygonum odoratum Lour was tested for their effects on a foodborne bacterium Salmonella choleraesuis subsp. choleraesuis ATCC 35640 using a broth dilution method. This essential oil showed a significant antibacterial activity against S. choleraesuis at the concentration of 200 µg/mL. Twenty-five volatile compounds were characterized from this essential oil by GC-MS, and aldehyde compounds were found abundant and accounted for more than three-fourths of the essential oil. Among the compounds characterized, dodecanal (C12 ) was the most abundant (55.5%), followed by decanal (C10 ) (11.6%). Both alkanals were effective against S. choleraesuis with the minimum growth inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 100 µg/mL. The most potent antibacterial activity against this bacterium was found with two minor compounds, dodecanol (lauryl alcohol) and 2E-dodecenal, both with each MBC of 6.25 µg/mL. Their primary antibacterial action against S. choleraesuis provably comes from their ability to function as nonionic surface-active agents (surfactants), disrupting the native function of integral membrane proteins nonspecifically. Thus, the antibacterial activity is mediated by biophysical processes. In the case of 2E-alkenals, a biochemical mechanism is also somewhat involved, depending on their alkyl chain length. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Effect of volatile organic compounds from bacteria on nematodes.

    PubMed

    Xu, You-Yao; Lu, Hao; Wang, Xin; Zhang, Ke-Qin; Li, Guo-Hong

    2015-09-01

    The five studied bacterial strains could produce volatile organic compounds (VOCs) that kill nematodes. Based on their 16S rRNA sequences, these strains were identified as Pseudochrobactrum saccharolyticum, Wautersiella falsenii, Proteus hauseri, Arthrobacter nicotianae, and Achromobacter xylosoxidans. The bacterial VOCs were extracted using solid-phase micro-extraction (SPME) and subsequently identified by GC/MS analysis. The VOCs covered a wide range of aldehydes, ketones, alkyls, alcohols, alkenes, esters, alkynes, acids, ethers, as well as heterocyclic and phenolic compounds. Among the 53 VOCs identified, 19 candidates, produced by different bacteria, were selected to test their nematicidal activity (NA) against Caenorhabditis elegans and Meloidogyne incognita. The seven compounds with the highest NAs were acetophenone, S-methyl thiobutyrate, dimethyl disulfide, ethyl 3,3-dimethylacrylate, nonan-2-one, 1-methoxy-4-methylbenzene, and butyl isovalerate. Among them, S-methyl thiobutyrate showed a stronger NA than the commercial insecticide dimethyl disulfide. It was reported for the first time here that the five bacterial strains as well as S-methyl thiobutyrate, ethyl 3,3-dimethylacrylate, 1-methoxy-4-methylbenzene, and butyl isovalerate possess NA. These strains and compounds might provide new insights in the search for novel nematicides.

  14. 75 FR 24404 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-05

    ... Organic Compound Automobile Refinishing Rules for Indiana AGENCY: Environmental Protection Agency (EPA... approved volatile organic compound (VOC) automobile refinishing rules to all persons in Indiana who sell or..., Volatile organic compounds. Dated: March 31, 2010. Walter W. Kovalick Jr., Acting Regional...

  15. Qualitative analysis of volatile organic compounds on biochar.

    PubMed

    Spokas, Kurt A; Novak, Jeffrey M; Stewart, Catherine E; Cantrell, Keri B; Uchimiya, Minori; Dusaire, Martin G; Ro, Kyoung S

    2011-10-01

    Qualitative identification of sorbed volatile organic compounds (VOCs) on biochar was conducted by headspace thermal desorption coupled to capillary gas chromatographic-mass spectrometry. VOCs may have a mechanistic role influencing plant and microbial responses to biochar amendments, since VOCs can directly inhibit/stimulate microbial and plant processes. Over 70 biochars encompassing a variety of parent feedstocks and manufacturing processes were evaluated and were observed to possess diverse sorbed VOC composition. There were over 140 individual chemical compounds thermally desorbed from some biochars, with hydrothermal carbonization (HTC) and fast pyrolysis biochars typically possessing the greatest number of sorbed volatiles. In contrast, gasification, thermal or chemical processed biochars, soil kiln mound, and open pit biochars possessed low to non-detectable levels of VOCs. Slow pyrolysis biochars were highly variable in terms of their sorbed VOC content. There were no clear feedstock dependencies to the sorbed VOC composition, suggesting a stronger linkage with biochar production conditions coupled to post-production handling and processing. Lower pyrolytic temperatures (⩽350°C) produced biochars with sorbed VOCs consisting of short carbon chain aldehydes, furans and ketones; elevated temperature biochars (>350°C) typically were dominated by sorbed aromatic compounds and longer carbon chain hydrocarbons. The presence of oxygen during pyrolysis also reduced sorbed VOCs. These compositional results suggest that sorbed VOCs are highly variable and that their chemical dissimilarity could play a role in the wide variety of plant and soil microbial responses to biochar soil amendment noted in the literature. This variability in VOC composition may argue for VOC characterization before land application to predict possible agroecosystem effects.

  16. Mapping Asian anthropogenic emissions of non-methane volatile organic compounds to multiple chemical mechanisms

    NASA Astrophysics Data System (ADS)

    Li, M.; Zhang, Q.; Streets, D. G.; He, K. B.; Cheng, Y. F.; Emmons, L. K.; Huo, H.; Kang, S. C.; Lu, Z.; Shao, M.; Su, H.; Yu, X.; Zhang, Y.

    2014-06-01

    An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. Taking the INTEX-B Asian NMVOC emission inventory as the case, we developed an improved speciation framework to generate model-ready anthropogenic NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs in this work, by using an explicit assignment approach and updated NMVOC profiles. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database v.4.2. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms. Gridded emissions for eight chemical mechanisms at 30 min × 30 min resolution as well as the auxiliary data are available at http://mic.greenresource.cn/intex-b2006. The framework proposed in this work can be also used to develop speciated NMVOC emissions for other regions.

  17. Mapping Asian anthropogenic emissions of non-methane volatile organic compounds to multiple chemical mechanisms

    NASA Astrophysics Data System (ADS)

    Li, M.; Zhang, Q.; Streets, D. G.; He, K. B.; Cheng, Y. F.; Emmons, L. K.; Huo, H.; Kang, S. C.; Lu, Z.; Shao, M.; Su, H.; Yu, X.; Zhang, Y.

    2013-12-01

    An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. In this work, we developed an improved speciation framework to generate model-ready anthropogenic Asian NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs by using an explicit assignment approach and updated NMVOC profiles, based on the total NMVOC emissions in the INTEX-B Asian inventory for the year 2006. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Gridded emissions for eight chemical mechanisms are developed at 30 min × 30 min resolution using various spatial proxies and are provided through the website: http://mic.greenresource.cn/intex-b2006. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms.

  18. Microbial cycling of volatile organic sulfur compounds in anoxic environments.

    PubMed

    Lomans, B P; Pol, A; Op den Camp, H J M

    2002-01-01

    Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source. In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments.

  19. Pervaporation investigation of recovery of volatile compounds from brown crab boiling juice.

    PubMed

    Martínez, Rodrigo; Sanz, M Teresa; Beltrán, Sagrario

    2014-10-01

    Pervaporation has been used to obtain aroma concentrates from brown crab boiling juice. The boiling juice and the obtained permeate have been analysed by Headspace Solid Phase Dynamic Extraction Gas Chromatography/Mass Spectrometry. The effect of feed temperature on the pervaporation performance of the membrane has been analysed. The permeate aroma profile, at 25 ℃ and 40 ℃, was different from that of the boiling juice. Enrichment factors for some of the volatile compounds were much lower than those obtained in model aqueous dilute solutions. Pervaporation performance can be significantly improved by modifying the permeant circuit to include two condensation stages.

  20. Polyphenols and Volatile Compounds in Commercial Chokeberry (Aronia melanocarpa) Products.

    PubMed

    Romani, Annalisa; Vignolini, Pamela; Ieri, Francesca; Heimler, Daniela

    2016-01-01

    Aronia melanocarpa (Michx.) Elliott commercial products (dried fruit, juice and compote) were analyzed for their polyphenol content by chromatographic and spectrophotometric analyses in order to ascertain the fate of this group of compounds when fresh fruit is processed and sold in different forms on the market. Different classes of polyphenols were investigated: hydroxycinnamic derivatives ranged from 0.65 mg/g to 4.30 mg/g, flavonoids from 0.36 mg/g to 1.12 mg/g, and anthocyanins from 0.65 to 7.08 mg/g sample. 4-O-Caffeoyl-quinic acid was tentatively identified for the first time in Aronia. In order to characterize better chokeberry juice, a GC profile of aroma compounds was obtained. The aroma juice compounds belong mainly to the chemical classes of alcohols (48.9%) and ketones (30.28%). The most abundant compound is 3-penthen-2-one (23.6%).

  1. Volatile and intermediate volatility organic compounds in suburban Paris: variability, origin and importance for SOA formation

    NASA Astrophysics Data System (ADS)

    Ait-Helal, W.; Borbon, A.; Sauvage, S.; de Gouw, J. A.; Colomb, A.; Gros, V.; Freutel, F.; Crippa, M.; Afif, C.; Baltensperger, U.; Beekmann, M.; Doussin, J.-F.; Durand-Jolibois, R.; Fronval, I.; Grand, N.; Leonardis, T.; Lopez, M.; Michoud, V.; Miet, K.; Perrier, S.; Prévôt, A. S. H.; Schneider, J.; Siour, G.; Zapf, P.; Locoge, N.

    2014-10-01

    Measurements of gaseous and particulate organic carbon were performed during the MEGAPOLI experiments, in July 2009 and January-February 2010, at the SIRTA observatory in suburban Paris. Measurements comprise primary and secondary volatile organic compounds (VOCs), of both anthropogenic and biogenic origins, including C12-C16 n-alkanes of intermediate volatility (IVOCs), suspected to be efficient precursors of secondary organic aerosol (SOA). The time series of gaseous carbon are generally consistent with times series of particulate organic carbon at regional scale, and are clearly affected by meteorology and air mass origin. Concentration levels of anthropogenic VOCs in urban and suburban Paris were surprisingly low (2-963 ppt) compared to other megacities worldwide and to rural continental sites. Urban enhancement ratios of anthropogenic VOC pairs agree well between the urban and suburban Paris sites, showing the regional extent of anthropogenic sources of similar composition. Contrary to other primary anthropogenic VOCs (aromatics and alkanes), IVOCs showed lower concentrations in winter (< 5 ppt) compared to summer (13-27 ppt), which cannot be explained by the gas-particle partitioning theory. Higher concentrations of most oxygenated VOCs in winter (18-5984 ppt) suggest their dominant primary anthropogenic origin. The respective role of primary anthropogenic gaseous compounds in regional SOA formation was investigated by estimating the SOA mass concentration expected from the anthropogenic VOCs and IVOCs (I / VOCs) measured at SIRTA. From an integrated approach based on emission ratios and SOA yields, 38 % of the SOA measured at SIRTA is explained by the measured concentrations of I / VOCs, with a 2% contribution by C12-C16 n-alkane IVOCs. From the results of an alternative time-resolved approach, the average IVOC contribution to SOA formation is estimated to be 7%, which is half of the average contribution of the traditional aromatic compounds (15%). Both

  2. Flash pyrolysis of coal, coal maceral, and coal-derived pyrite with on-line characterization of volatile sulfur compounds

    USGS Publications Warehouse

    Chou, I.-Ming; Lake, M.A.; Griffin, R.A.

    1988-01-01

    A Pyroprobe flash pyrolysis-gas chromatograph equipped with a flame photometric detector was used to study volatile sulfur compounds produced during the thermal decomposition of Illinois coal, coal macerals and coal-derived pyrite. Maximum evolution of volatile organic sulfur compounds from all coal samples occurred at a temperature of approximately 700??C. At this temperature, the evolution of thiophene, its alkyl isomers, and short-chain dialkyl sulfide compounds relative to the evolution of benzothiophene and dibenzothiophene compounds was greater from coal high in organic sulfur than from coal low in organic sulfur. The variation in the evolution of sulfur compounds observed for three separate coal macerals (exinite, vitrinite, and inertinite) was similar to that observed for whole coal samples. However, the variation trend for the macerals was much more pronounced. Decomposition of coal-derived pyrite with the evolution of elemental sulfur was detected at a temperature greater than 700??C. The results of this study indicated that the gas chromotographic profile of the volatile sulfur compounds produced during flash pyrolysis of coals and coal macerals varied as a function of the amount of organic sulfur that occurred in the samples. Characterization of these volatile sulfur compounds provides a better understanding of the behavior of sulfur in coal during the thermolysis process, which could be incorporated in the design for coal cleaning using flash pyrolysis techniques. ?? 1988.

  3. Thermogenic respiratory processes drive the exponential increase of volatile organic compound emissions in Macrozamia cycad cones.

    PubMed

    Terry, L Irene; Roemer, Robert B; Booth, David T; Moore, Chris J; Walter, Gimme H

    2016-07-01

    An important outcome of plant thermogenesis is increased emissions of volatiles that mediate pollinator behaviour. We investigated whether the large increase in emissions, mainly the monoterpene ß-myrcene (>90%), during daily thermogenic events of Macrozamia macleayi and lucida cycad cones are due solely to the influence of high cone temperatures or are, instead, a result of increased respiratory rates during thermogenesis. We concurrently measured temperature, oxygen consumption and ß-myrcene emission profiles during thermogenesis of pollen cones under typical environmental temperatures and during experimental manipulations of cone temperatures and aerobic conditions, all in the dark. The exponential rise in ß-myrcene emissions never occurred without a prior, large increase in respiration, whereas an increase in cone temperature alone did not increase emissions. When respiration during thermogenesis was interrupted by anoxic conditions, ß-myrcene emissions decreased. The increased emission rates are not a result of increased cone temperature per se (through increased enzyme activity or volatilization of stored volatiles) but are dependent on biosynthetic pathways associated with increased respiration during thermogenesis that provide the carbon, energy (ATP) and reducing compounds (NADPH) required for ß-myrcene production through the methylerythritol phosphate (MEP) pathway. These findings establish the significant contribution of respiration to volatile production during thermogenesis.

  4. Identification of volatile organic compounds in human cerumen

    PubMed Central

    Prokop-Prigge, Katharine A.; Thaler, Erica; Wysocki, Charles J.; Preti, George

    2014-01-01

    We report here the initial examination of volatile organic compounds (VOCs) emanating from human earwax (cerumen). Recent studies link a single nucleotide polymorphism (SNP) in the adenosine triphosphate (ATP) binding cassette, sub-family C, member 11 gene (ABCC11) to the production of different types of axillary odorants and cerumen. ABCC11 encodes an ATP-driven efflux pump protein that plays an important function in ceruminous apocrine glands of the auditory canal and the secretion of axillary odor precursors. The type of cerumen and underarm odor produced by East Asians differ markedly from that produced by non-Asians. In this initial report we find that both groups emit many of the same VOCs but differ significantly in the amounts produced. The principal odorants are volatile organic C2-to-C6 acids. The physical appearance of cerumen from the two groups also matches previously reported ethnic differences, viz., cerumen from East Asians appears dry and white while that from non-Asians is typically wet and yellowish-brown. PMID:24572763

  5. Identification of volatile organic compounds in human cerumen.

    PubMed

    Prokop-Prigge, Katharine A; Thaler, Erica; Wysocki, Charles J; Preti, George

    2014-03-15

    We report here the initial examination of volatile organic compounds (VOCs) emanating from human earwax (cerumen). Recent studies link a single nucleotide polymorphism (SNP) in the adenosine triphosphate (ATP) binding cassette, sub-family C, member 11 gene (ABCC11) to the production of different types of axillary odorants and cerumen. ABCC11 encodes an ATP-driven efflux pump protein that plays an important function in ceruminous apocrine glands of the auditory canal and the secretion of axillary odor precursors. The type of cerumen and underarm odor produced by East Asians differ markedly from that produced by non-Asians. In this initial report we find that both groups emit many of the same VOCs but differ significantly in the amounts produced. The principal odorants are volatile organic C2-to-C6 acids. The physical appearance of cerumen from the two groups also matches previously reported ethnic differences, viz., cerumen from East Asians appears dry and white while that from non-Asians is typically wet and yellowish-brown.

  6. First Characterisation of Volatile Organic Compounds Emitted by Banana Plants

    PubMed Central

    Berhal, Chadi; De Clerck, Caroline; Fauconnier, Marie-Laure; Levicek, Carolina; Boullis, Antoine; Kaddes, Amine; Jijakli, Haïssam M.; Verheggen, François; Massart, Sébastien

    2017-01-01

    Banana (Musa sp.) ranks fourth in term of worldwide fruit production, and has economical and nutritional key values. The Cavendish cultivars correspond to more than 90% of the production of dessert banana while cooking cultivars are widely consumed locally around the banana belt production area. Many plants, if not all, produce Volatile Organic Compounds (VOCs) as a means of communication with their environment. Although flower and fruit VOCs have been studied for banana, the VOCs produced by the plant have never been identified despite their importance in plant health and development. A volatile collection methodology was optimized to improve the sensitivity and reproducibility of VOCs analysis from banana plants. We have identified 11 VOCs for the Cavendish, mainly (E,E)-α-farnesene (87.90 ± 11.28 ng/μl), methyl salicylate (33.82 ± 14.29) and 6-methyl-5-hepten-2-one (29.60 ± 11.66), and 14 VOCs for the Pacific Plantain cultivar, mainly (Z,E)-α-farnesene (799.64 ± 503.15), (E,E)-α-farnesene (571.24 ± 381.70) and (E) β ocimene (241.76 ± 158.49). This exploratory study paves the way for an in-depth characterisation of VOCs emitted by Musa plants. PMID:28508885

  7. First Characterisation of Volatile Organic Compounds Emitted by Banana Plants.

    PubMed

    Berhal, Chadi; De Clerck, Caroline; Fauconnier, Marie-Laure; Levicek, Carolina; Boullis, Antoine; Kaddes, Amine; Jijakli, Haïssam M; Verheggen, François; Massart, Sébastien

    2017-05-16

    Banana (Musa sp.) ranks fourth in term of worldwide fruit production, and has economical and nutritional key values. The Cavendish cultivars correspond to more than 90% of the production of dessert banana while cooking cultivars are widely consumed locally around the banana belt production area. Many plants, if not all, produce Volatile Organic Compounds (VOCs) as a means of communication with their environment. Although flower and fruit VOCs have been studied for banana, the VOCs produced by the plant have never been identified despite their importance in plant health and development. A volatile collection methodology was optimized to improve the sensitivity and reproducibility of VOCs analysis from banana plants. We have identified 11 VOCs for the Cavendish, mainly (E,E)-α-farnesene (87.90 ± 11.28 ng/μl), methyl salicylate (33.82 ± 14.29) and 6-methyl-5-hepten-2-one (29.60 ± 11.66), and 14 VOCs for the Pacific Plantain cultivar, mainly (Z,E)-α-farnesene (799.64 ± 503.15), (E,E)-α-farnesene (571.24 ± 381.70) and (E) β ocimene (241.76 ± 158.49). This exploratory study paves the way for an in-depth characterisation of VOCs emitted by Musa plants.

  8. 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.

  9. Biofiltration for control of volatile organic compounds (VOCS)

    SciTech Connect

    Bishop, D.F.; Govind, R.

    1995-10-01

    Air biofiltration is a promising technology for control of air emissions of biodegradable volatile organic compounds (VOCs). In conjunction with vacuum extraction of soils or air stripping of ground water, it can be used to mineralize VOCs removed from contaminated soil or groundwater. The literature describes three major biological systems for treating contaminated air bioscrubbers, biotrickling filters and biofilters. Filter media can be classified as: bioactive fine or irregular particulates, such as soil, peat, compost or mixtures of these materials; pelletized, which are randomly packed in a bed; and structured, such as monoliths with defined or variable passage size and geometry. The media can be made of sorbing and non-absorbing materials. Non-bioactive pelletized and structured media require recycled solutions of nutrients and buffer for efficient microbial activity and are thus called biotrickling filters. Extensive work has been conducted to improve biofiltration by EPA`s Risk Reduction Engineering Laboratory and the University of Cincinnati in biofilters using pelletized and structured media and improved operational approaches. Representative VOCs in these studies included compounds with a range of aqueous solubilities and octanol-water partition coefficients. The compounds include iso-pentane, toluene, methylene chloride, trichloroethylene (TCE), ethyl benzene, chlorobenzene and perchloroethylene (PCE) and alpha ({alpha}-) pinene. Comparative studies were conducted with peat/compost biofilters using isopentane and {alpha}-pinene. Control studies were also conducted to investigate adsorption/desorption of contaminants on various media using mercuric chloride solution to insure the absence of bioactivity.

  10. Aldol Condensation of Volatile Carbonyl Compounds in Acidic Aerosols

    NASA Astrophysics Data System (ADS)

    Noziere, B.; Esteve, W.

    2003-12-01

    Reactions of volatile organic compounds in acidic aerosols have been shown recently to be potentially important for organic aerosol formation and growth. Aldol condensation, the acid-catalyzed polymerization of carbonyl compounds, is a likely candidate to enhance the flux of organic matter from the gas phase to the condensed phase in the atmosphere. Until now these reactions have only been characterized for conditions relevant to synthesis (high acidities and liquid phase systems) and remote from atmospheric ones. In this work, the uptake of gas-phase acetone and 2,4\\-pentanedione by sulfuric acid solutions has been measured at room temperature using a Rotated Wetted Wall Reactor coupled to a Mass Spectrometer. The aldol condensation rate constants for 2,4\\-pentanedione measured so far for sulfuric acid solutions between 96 and 70 % wt. display a variation with acidity in agreement with what predicted in the organic chemical literature. The values of these constants, however, are much lower than expected for this compound, and comparable to the ones of acetone. Experiments are underway to complete this study to lower acidities and understand the discrepancies with the predicted reactivity.

  11. Volatile organic compounds adsorption onto neat and hybrid bacterial cellulose

    NASA Astrophysics Data System (ADS)

    Ion, Violeta Alexandra; Pârvulescu, Oana Cristina; Dobre, Tănase

    2015-04-01

    Adsorption dynamics of VOCs (volatile organic compounds) vapour from air streams onto fixed bed adsorbent were measured and simulated under various operation conditions. Isopropanol (IPA) and n-hexane (HEX) were selected as representatives of polar and nonpolar VOCs, whereas bacterial cellulose (BC) and BC incorporated with magnetite nanoparticles (M/BC), were tested as adsorbents. An experimental study emphasizing the influence of air superficial velocity (0.7 cm/s and 1.7 cm/s), operation temperature (30 °C and 40 °C), adsorbate and adsorbent type, on fixed bed saturation curves was conducted. Optimal adsorption performances evaluated in terms of saturation adsorption capacity were obtained for the adsorption of polar compound (IPA) onto M/BC composite (0.805 g/g) and of nonpolar compound (HEX) onto neat BC (0.795 g/g), respectively, at high values of air velocity and operation temperature. A mathematical model including mass balance of VOC species, whose parameters were fitted based on experimental data, was developed in order to predict the fixed bed saturation curves. A 23 statistical model indicating a significant increase in adsorption performances with process temperature was validated under the experimental conditions.

  12. Volatile organic compounds in selected micro-environments.

    PubMed

    Hinwood, A L; Berko, H N; Farrar, D; Galbally, I E; Weeks, I A

    2006-04-01

    A program of sampling for volatile organic compounds (VOCs) in ambient air was undertaken in selected locations and micro-environments in Perth, Western Australia to characterise concentrations of target VOCs and to determine the relative strength of the contributing sources to ambient air in different micro-environments in a major Australian city. Twenty-seven locations were sampled and, of the forty-one target compounds, 26 VOCs were detected in the samples collected. The highest concentrations were recorded for benzene, toluene, ethylbenzene, xylenes (BTEX), chloroform and styrene. The maximum 12-h toluene and benzene concentrations observed were from a basement carpark and were 24.7 parts per billion (ppb) and 5.6 ppb, respectively. The maximum xylenes concentration was 29.4 ppb and occurred in a nightclub where styrene was also detected. A factor analysis of the data was undertaken. Two key factors emerge that appear to be associated with petroleum and motor vehicles and environmental tobacco smoke. A third significant occurrence was a high concentration of chloroform that was observed at a sports centre complex with a swimming pool text and was uncorrelated with other compounds in the data set. This study indicates that locations associated with motor vehicles and petrol fuel, tobacco and wood smoke and chlorinated water represent the major risks for personal exposure to VOCs in Perth.

  13. 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.

  14. Modeling Emissions of Volatile Organic Compounds from New Carpets

    SciTech Connect

    Little, J.C.; Hodgson, A.T.; Gadgil, A.J.

    1993-02-01

    A simple model is proposed to account for observed emissions of volatile organic compounds (VOCs) from new carpets. The model assumes that the VOCs originate predominantly in a uniform slab of polymer backing material. Parameters for the model (the initial concentration of a VOC in the polymer, a diffusion coefficient and an equilibrium polymer/air partition coefficient) are obtained from experimental data produced by a previous chamber study. The diffusion coefficients generally decrease as the molecular weight of the VOCs increase, while the polymer/air partition coefficients generally increase as the vapor pressure of the compounds decrease. In addition, for two of the study carpets that have a styrene-butadiene rubber (SBR) backing, the diffusion and partition coefficients are similar to independently reported values for SBR. The results suggest that predictions of VOCs emissions from new carpets may be possible based solely on a knowledge of the physical properties of the relevant compounds and the carpet backing material. However, a more rigorous validation of the model is desirable.

  15. Modeling emissions of volatile organic compounds from new carpets

    NASA Astrophysics Data System (ADS)

    Little, John C.; Hodgson, Alfred T.; Gadgil, Ashok J.

    A simple model is proposed to account for observed emissions of volatile organic compounds (VOCs) from new carpets. The model assumes that the VOCs originate predominantly in a uniform slab of polymer backing material. Parameters for the model (the initial concentration of a VOC in the polymer, a diffusion coefficient and an equilibrium polymer/air partition coefficient) are obtained from experimental data produced by a previous chamber study. The diffusion coefficients generally decrease as the molecular weight of the VOCs increase, while the partition coefficients generally increase as the vapor pressure of the compounds decreases. In addition, for two of the study carpets that have a styrene-butadiene rubber (SBR) backing, the diffusion and partition coefficients are similar to independently reported values for SBR. The results suggest that prediction of VOC emissions from new carpets may be possible based solely on a knowledge of the physical properties of the relevant compounds and the carpet backing material. However, a more rigorous validation of the model is desirable.

  16. Indoor chemistry. Ozone, volatile organic compounds, and carpets

    SciTech Connect

    Weschler, C.J. ); Hodgson, A.T.; Wooley, J.D. )

    1992-12-01

    Volatile organic compounds (VOCs) have been measured in a freshly carpeted 20-m[sup 3] stainless-steel room in both the absence and presence of ozone (ozone concentrations ranging from 30 to 50 ppb, with one experiment conducted at 400 ppb). Four different types of carpeting were exposed, and in each set of experiments, the room was ventilated at 1 air exchange/h. The gas-phase concentrations of selected carpet emissions (e.g., 4-phenylcyclohexene, 4-vinylcyclohexene, and styrene) significantly decreased in the presence of ozone. Conversely, the concentrations of other compounds (e.g., formaldehyde, acetaldehyde, and aldehydes with between 5 and 10 carbons) significantly increased. Furthermore, the total concentration of VOCs increased markedly in the presence of ozone. The additional VOCs appear to have been generated by reactions between ozone and relatively nonvolatile compounds associated with the carpets. These studies suggest that VOCs measured within a building at elevated ozone levels (>30 ppb) may differ from those measured at lower ozone levels (<10 ppb). 12 refs., 2 figs., 6 tabs.

  17. Methods in plant foliar volatile organic compounds research1

    PubMed Central

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; Gauci, Vincent

    2015-01-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant–plant and plant–insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas analysis, usually based on gas chromatography and soft chemical ionization mass spectrometry. Until now, these techniques (especially the latter one) have been developed and used primarily by physicists and analytical scientists, who have used them in a wide range of scientific research areas (e.g., aroma, disease biomarkers, hazardous compound detection, atmospheric chemistry). The interdisciplinary nature of plant foliar VOC research has recently attracted the attention of biologists, bringing them into the field of applied environmental analytical sciences. In this paper, we review the sampling methods and available analytical techniques used in plant foliar VOC research to provide a comprehensive resource that will allow biologists moving into the field to choose the most appropriate approach for their studies. PMID:26697273

  18. Methods in plant foliar volatile organic compounds research.

    PubMed

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; Gauci, Vincent

    2015-12-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant-plant and plant-insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas analysis, usually based on gas chromatography and soft chemical ionization mass spectrometry. Until now, these techniques (especially the latter one) have been developed and used primarily by physicists and analytical scientists, who have used them in a wide range of scientific research areas (e.g., aroma, disease biomarkers, hazardous compound detection, atmospheric chemistry). The interdisciplinary nature of plant foliar VOC research has recently attracted the attention of biologists, bringing them into the field of applied environmental analytical sciences. In this paper, we review the sampling methods and available analytical techniques used in plant foliar VOC research to provide a comprehensive resource that will allow biologists moving into the field to choose the most appropriate approach for their studies.

  19. Identification and quantification of volatile organic compounds from a dairy

    NASA Astrophysics Data System (ADS)

    Filipy, Jenny; Rumburg, Brian; Mount, George; Westberg, Hal; Lamb, Brian

    Volatile organic compounds (VOCs) that contribute to odor and air quality problems have been identified from the Washington State University Knott Dairy Farm using gas chromatography-mass spectroscopy (GC-MS). Eighty-two VOCs were identified at a lactating cow open stall and 73 were detected from a slurry wastewater lagoon. These compounds included alcohols, aldehydes, ketones, esters, ethers, aromatic hydrocarbons, halogenated hydrocarbons, terpenes, other hydrocarbons, amines, other nitrogen containing compounds, and sulfur-containing compounds. The concentration of VOCs directly associated with cattle waste increased with ambient air temperature, with the highest concentrations present during the summer months. Concentrations of most detected compounds were below published odor detection thresholds. Emission rates of ethanol (1026±513 μg cow -1 s -1) and dimethyl sulfide (DMS) (13.8±10.3 μg cow -1 s -1) were measured from the lactating stall area using an atmospheric tracer method and concentrations were plotted using data over a 2-year period. Emission rates of acetone (3.03±0.85 ng cow -1 s -1), 2-butanone (145±35 ng cow -1 s -1), methyl isobutyl ketone (3.46±1.11 ng cow -1 s -1), 2-methyl-3-pentanone (25.1±8.0 ng cow -1 s -1), DMS (2.19±0.92 ng cow -1 s -1), and dimethyl disulfide (DMDS) (16.1±3.9 ng cow -1 s -1) were measured from the slurry waste lagoon using a laboratory emission chamber.

  20. Subjective reactions to volatile organic compounds as air pollutants

    NASA Astrophysics Data System (ADS)

    Mølhave, Lars; Grønkjær, John; Larsen, Søren

    Human subjective reactions to indoor air pollution in the form of volatile organic compounds in five concentrations ⩽ mg m -3 were examined in a climate chamber under controlled conditions in a balanced experimental design. The reactions of 25 subjects were registered in two questionnaires containing 25 and six questions and on a linear analogue rating scale. Each subject was tested for one day including four runs in each of the five treatments of 50 min duration. Dose effects were found for perceived odour intensity at 3 mgm -3. Air quality, need for ventilation, irritation of eye and nose showed significant effect at 8 mg m -3. Significant reduced well being was reported at 25 mgm -3. The analyses indicated that lower threshold for some of these effects would have been found if more subjects or longer exposure-times had been used. Gender, age, occupational education and smoking habits were co-factors for many of the symptoms reported.

  1. Source apportionment of ambient volatile organic compounds in Beijing.

    PubMed

    Song, Yu; Shao, Min; Liu, Ying; Lu, Sihua; Kuster, William; Goldan, Paul; Xie, Shaodong

    2007-06-15

    The ambient air quality standard for ozone is frequently exceeded in Beijing in summer and autumn. Source apportionments of volatile organic compounds (VOCs), which are precursors of ground-level ozone formation, can be helpful to the further study of tropospheric ozone formation. In this study, ambient concentrations of VOCs were continuously measured with a time resolution of 30 min in August 2005 in Beijing. By using positive matrix factorization (PMF), eight sources for the selected VOC species were extracted. Gasoline-related emissions (the combination of gasoline exhaust and gas vapor), petrochemicals, and liquefied petroleum gas (LPG) contributed 52, 20, and 11%, respectively, to total ambient VOCs. VOC emissions from natural gas (5%), painting (5%), diesel vehicles (3%), and biogenic emissions (2%) were also identified. The gasoline-related, petrochemical, and biogenic sources were estimated to be the major contributors to ozone formation potentials in Beijing.

  2. Source apportionment of volatile organic compounds in Tehran, Iran.

    PubMed

    Sarkhosh, Maryam; Mahvi, Amir Hossein; Yunesian, Masud; Nabizadeh, Ramin; Borji, Saeedeh Hemmati; Bajgirani, Ali Ghiami

    2013-04-01

    Identifying the sources of volatile organic compounds (VOCs) is key issue to reducing ground-level ozone and PAN. A multivariate receptor model (Unmix) was used for the determination of the contributions of VOCs sources in Tehran-Iran. Concentrations of ambient C2-C10 VOCs were measured continuously and online at the center of Tehran city during the winter of 2012. A high correlation coefficient existed between measured and predicted values (R (2) = 0.99), indicating that the data were well modeled. Five possible VOCs source categories were identified and mobile sources such as vehicle exhaust (61 %) and fuel evaporation (12 %) more than half of the total VOC concentration. City gas and CNG sources, biogenic source, and industrial solvent source categories accounted for 17 %, 8 % and 2 % of the total VOC, respectively. Result showed Unmix for VOCs source apportionment can be used to analyze and generate air pollution control strategies and policies.

  3. Laboratory methods for volatile organic compounds evolved in mineralization studies

    SciTech Connect

    Hickey, W.J.; Arnold, S.M.; Moran, B.N.

    1995-11-01

    A system to study mineralization of volatile organic compounds (VOCs) was developed using commercially available solid-phase VOC traps and impingers to collect CO{sub 2} as well as VOCs breaking out from the solid-phase trap. The efficiencies of VOC traps containing activated charcoal (AC) or graphitized carbon black (GCB) for absorbing [{sup 14}C]trichloroethylene ([{sup 14}C]TCE) and {sup 14}CO{sub 2} were evaluated, and approaches for minimizing VOC losses from reaction vessels were established. Mass balances showed AC and GCB absorbed similar amounts of [{sup 14}C]TCE. However, GCB had no detectable {sup 14}CO{sub 2} retention, whereas AC absorbed about 7% of the {sup 14}CO{sub 2}. Because {sup 14}CO{sub 2} absorption could influence the interpretation of mineralization experiments, GCB was concluded to be the better VOC-trapping matrix.

  4. Volatile Organic Compound Optical Fiber Sensors: A Review

    PubMed Central

    Elosua, Cesar; Matias, Ignacio R.; Bariain, Candido; Arregui, Francisco J.

    2006-01-01

    Volatile organic compound (VOC) detection is a topic of growing interest with applications in diverse fields, ranging from environmental uses to the food or chemical industries. Optical fiber VOC sensors offering new and interesting properties which overcame some of the inconveniences found on traditional gas sensors appeared over two decades ago. Thanks to its minimum invasive nature and the advantages that optical fiber offers such as light weight, passive nature, low attenuation and the possibility of multiplexing, among others, these sensors are a real alternative to electronic ones in electrically noisy environments where electronic sensors cannot operate correctly. In the present work, a classification of these devices has been made according to the sensing mechanism and taking also into account the sensing materials or the different methods of fabrication. In addition, some solutions already implemented for the detection of VOCs using optical fiber sensors will be described with detail.

  5. Residential pollutants and ventilation strategies: Volatile organic compounds and radon

    SciTech Connect

    Grimsrud, D.T.; Hadlich, D.E.

    1999-07-01

    This paper reviews literature that reports investigations of residential ventilation and indoor air quality. Two important residential pollutant classes, volatile organic compounds and radon, are examined. A companion paper examines moisture and combustion pollutants. Control strategies recommended from the review include appropriate building design to prevent or limit the sources of the pollutants within the space, proper operation and maintenance to prevent adverse conditions from developing during the building's life and appropriate use of ventilation. The characteristics of these pollutant sources suggest that ventilation systems in residences should have several properties. They should have the extra capacity available to reduce short bursts of pollution, be located close to the expected source of the contamination, and be inexpensive. Mitigation of radon is technically a major success using a form of task ventilation. Whole-house ventilation is, at best, a secondary form of control of excess radon in residences.

  6. Flux Measurements of Volatile Organic Compounds from an Urban Landscape

    SciTech Connect

    Velasco, E.; Lamb, Brian K.; Pressley, S.; Allwine, Eugene J.; Westberg, Halvor; Jobson, B Tom T.; Alexander, M. Lizabeth; Prazeller, Peter; Molina, Luisa; Molina, Mario J.

    2005-10-19

    Direct measurements of volatile organic compound (VOC) emissions that include all anthropogenic and biogenic emission sources in urban areas are a missing requirement to evaluate emission inventories and constrain current photochemical modelling practices. Here we demonstrate the use of micrometeorological techniques coupled with fast-response sensors to measure urban VOC fluxes from a neighborhood of Mexico City, where the spatial variability of surface cover and roughness is high. Fluxes of olefins, methanol, acetone, toluene and C2-benzenes were measured and compared with the local gridded emission inventory. VOC fluxes exhibited a clear diurnal pattern with a strong relationship to vehicular traffic. Recent photochemical modeling results suggest that VOC emissions are significantly underestimated in Mexico City1, but the measured VOC fluxes described here indicate that the official emission inventory2 is essentially correct. Thus, other explanations are needed to explain the photochemical modelling results.

  7. Alveolar air volatile organic compound extractor for clinical breath sampling.

    PubMed

    de Silva, Geethanga; Beyette, Fred R

    2014-01-01

    Alveolar air Volatile Organic Compound (VOC) extractor is a handheld breath-sampling device for clinical breath analysis. The device consists two main components: (1) An alveolar air separator, (2) A VOC extractor. The alveolar air separator splits exhaled air based on total exhaled air volume directing alveolar air towards the VOC extractor and dead space air to into an exhaust channel. The VOC extractor collects the VOCs from alveolar air into a modified Sold Phase Micro Extraction (SPME) filament. Feasibility of using the SPME filament to collect a quantifiable breath sample directly from exhaled breath is experimentally validated. Exhaled breath acetone is quantified using alveolar air VOC extractor and a GC/MS system.

  8. Organic volatile sulfur compounds in inland aquatic systems

    SciTech Connect

    Richards, S.R.

    1991-01-01

    The speciation, concentration, and fluxes of organic volatile sulfur compounds (VSCs) in a wide variety of inland aquatic systems wee studied. Dissolved VSCs were sparged from water samples, trapped cryogenically, and quantified by gas chromatograph equipped with a flame photometric detector. Species detected and mean surface water concentrations were: carbonyl sulfide (COS), 0.091-7.6 nM; methanethiol (MSH), undetected-180 nM; dimethyl sulfide (DMS), 0.48-1290 nM; carbon disulfide (CS[sub 2]), undetected-69 nM; dimethyl disulfide (DMDS), undetected-68 nM. The range in surface water concentrations of over five orders of magnitude was influenced principally by lake depth and sulfate concentration ([SO[sub 4][sup 2[minus

  9. [Definition and Control Indicators of Volatile Organic Compounds in China].

    PubMed

    Jiang, Mei; Zou, Lan; Li, Xiao-qian; Che, Fei; Zhao, Guo-hua; Li, Gang; Zhang, Guo-ning

    2015-09-01

    Volatile organic compounds (VOCs) are the most complex of a wide range of pollutants that harms human health and ecological environment. However, various countries around the world differ on its definition and control indicators. Its definition, control indicators and monitoring methods of our country and local standards were also different. Based on detailed analysis of the definitions and control indicators of VOCs, the recommendations were proposed: the definition of VOCs should be different according to the different concerns between "air quality management" and "pollution emissions management"; base on different control way from production source, technological process, terminal emission, total discharge control, the control indicators system consists of 10 indicators; to formulate industry VOCs emissions standards, the most effective control way and indicators should be chosen according to characteristics of production process, way of VOCs emissions and possible control measures, etc.

  10. Detection of volatile organic compounds using surface enhanced Raman scattering

    SciTech Connect

    Chang, A S; Maiti, A; Ileri, N; Bora, M; Larson, C C; Britten, J A; Bond, T C

    2012-03-22

    The authors present the detection of volatile organic compounds directly in their vapor phase by surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. The type of nanopillars is known as the tapered pillars. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of toluene vapor. The results show that SERS signal from a toluene vapor concentration of ppm level can be achieved, and the toluene vapor can be detected within minutes of exposing the SERS substrate to the vapor. A simple adsorption model is developed which gives results matching the experimental data. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors.

  11. Investigation of michelson interferometer for volatile organic compound sensor

    NASA Astrophysics Data System (ADS)

    Marzuarman; Rivai, Muhammad; Arief Sardjono, Tri; Purwanto, Djoko

    2017-05-01

    The sensor device is required to monitor harmful gases in the environments and industries. Many volatile organic compounds adsorbed on the sensor material will result in changes of the optical properties including the refractive index and the film thickness. This study designed and realized a vapor detection device using the principle of Michelson Interferometer. The laser light beamed with a wavelength of 620 nm was divided by using a beam splitter. Interference occurredwhen the two separated lights were recombined. The phase difference between the two beams determined whether the interference would destruct or construct each other to produce the curved fringes. The vapor samples used in these experiments were ethanol and benzene. The results showed that the ethanol concentration of 1611-32210 ppm produced a fringe shift of 197 pixels, while the concentration of benzene of 964-19290 ppm produced a fringe shift of 273 pixels.

  12. Essential Oil Chemical Composition and Headspace Volatiles Profile of Achillea coarctata from Serbia.

    PubMed

    Kostevski, Ivana R; Petrović, Goran M; Stojanović, Gordana S; Stamenković, Jelena G; Zlatković, Bojan K

    2016-04-01

    This study reports the essential oil composition and headspace volatiles profile of Achillea coarctata Poir. from Serbia. The inflorescences, stems and leaves, and the aerial parts of A. coarctata were analyzed separately. Germacrene D, α-terpineol and 1,8-cineole were the main constituents of the aerial parts essential oil; 1,8-cineole, cis-cadin-4-en-7-ol and α-terpineol were the most dominant compounds in the inflorescence essential oil, while the most abundant components in the stem and leaf oil were germacrene D, cis-cadin-4-en-7-ol and ledol. The percentages of monoterpenoids and sesquiterpenoids in the aerial parts were the same, while there were differences in distribution of these compound classes in inflorescence and stem and leaf essential oils. The major components of the headspace volatiles were the same for aerial parts, inflorescence and stem and leaves: 1,8-cineole, β-pinene and α-pinene.

  13. Emissions of biogenic volatile organic compounds & their photochemical transformation

    NASA Astrophysics Data System (ADS)

    Yu, Zhujun; Hohaus, Thorsten; Tillmann, Ralf; Andres, Stefanie; Kuhn, Uwe; Rohrer, Franz; Wahner, Andreas; Kiendler-Scharr, Astrid

    2015-04-01

    Natural and anthropogenic activities emit volatile organic compounds (VOC) into the atmosphere. While it is known that land vegetation accounts for 90% of the global VOC emissions, only a few molecules' emission factors are understood. Through VOCs atmospheric oxidation intermediate products are formed. The detailed chemical mechanisms involved are insufficiently known to date and need to be understood for air quality management and climate change predictions. In an experiment using a PTR-ToF-MS with the new-built plant chamber SAPHIR-PLUS in Forschungszentrum Juelich, biogenic emissions of volatile organic compounds (BVOC) from Quercus ilex trees were measured. The BVOC emissions were dominated by monoterpenes, minor emissions of isoprene and methanol were also observed with the overall emission pattern typical for Quercus ilex trees in the growing season. Monoterpenes and isoprene emissions showed to be triggered by light. Additionally, their emissions showed clear exponential temperature dependence under constant light condition as reported in literature. As a tracer for leaf growth, methanol emission showed an abrupt increase at the beginning of light exposure. This is explained as instantaneous release of methanol produced during the night once stomata of leaves open upon light exposure. Emission of methanol showed a near linear increase with temperature in the range of 10 to 35 °C. BVOC were transferred from the plant chamber PLUS to the atmospheric simulation chamber SAPHIR, where their oxidation products from O3 oxidation were measured with PTR-ToF-MS. Gas phase oxidation products such as acetone and acetaldehyde were detected. A quantitative analysis of the data will be presented, including comparison of observations to the Master Chemical Mechanism model.

  14. Bioactive volatile organic compounds from Antarctic (sponges) bacteria.

    PubMed

    Papaleo, Maria Cristiana; Romoli, Riccardo; Bartolucci, Gianluca; Maida, Isabel; Perrin, Elena; Fondi, Marco; Orlandini, Valerio; Mengoni, Alessio; Emiliani, Giovanni; Tutino, Maria Luisa; Parrilli, Ermenegilda; de Pascale, Donatella; Michaud, Luigi; Lo Giudice, Angelina; Fani, Renato

    2013-09-25

    Antarctic bacteria represent a reservoir of unexplored biodiversity, which, in turn, might be correlated to the synthesis of still undescribed bioactive molecules, such as antibiotics. In this work we have further characterized a panel of four marine Antarctic bacteria able to inhibit the growth of human opportunistic multiresistant pathogenic bacteria belonging to the Burkholderia cepacia complex (responsible for the 'cepacia' syndrome in Cystic Fibrosis patients) through the production of a set of microbial Volatile Organic Compounds (mVOCs). A list of 30 different mVOCs synthesized under aerobic conditions by Antarctic bacteria was identified by GC-SPME analysis. Cross-streaking experiments suggested that Antarctic bacteria might also synthesize non-volatile molecules able to enhance the anti-Burkholderia activity. The biosynthesis of such a mixture of mVOCs was very probably influenced by both the presence/absence of oxygen and the composition of media used to grow the Antarctic strains. The antimicrobial activity exhibited by Antarctic strains also appeared to be more related to their taxonomical position rather than to the sampling site. Different Bcc bacteria were differently sensitive to the 'Antarctic' mVOCs and this was apparently related neither to the taxonomical position of the different strains nor to their source. The genome sequence of three new Antarctic strains was determined revealing that only P. atlantica TB41 possesses some genes belonging to the nrps-pks cluster. The comparative genomic analysis performed on the genome of the four strains also revealed the presence of a few genes belonging to the core genome and involved in the secondary metabolites biosynthesis. Data obtained suggest that the antimicrobial activity exhibited by Antarctic bacteria might rely on a (complex) mixture of mVOCs whose relative concentration may vary depending on the growth conditions. Besides, it is also possible that the biosynthesis of these compounds might occur

  15. A comparison of solid-phase microextraction (SPME) with simultaneous distillation-extraction (SDE) for the analysis of volatile compounds in heated beef and sheep fats.

    PubMed

    Watkins, P J; Rose, G; Warner, R D; Dunshea, F R; Pethick, D W

    2012-06-01

    A comparison has been made on the application of SPME and SDE for the extraction of volatile compounds from heated beef and sheep fats with separation and measurement by gas chromatography-mass spectrometry. As far as we know, this report represents the first time that such a comparison has been made for the measurement of volatile compounds in heated sheep fat. Approximately 100 compounds (in relatively high abundance) were characterised in the volatile profiles of heated beef and sheep fats using both techniques. Differences were observed in the volatile profiles obtained from each technique, independent of compound class. Rather than rate one technique as superior to another, the techniques can be regarded as complementary to each other. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  16. Characterization of volatiles and identification of odor-active compounds of rocket leaves.

    PubMed

    Raffo, Antonio; Masci, Maurizio; Moneta, Elisabetta; Nicoli, Stefano; Sánchez Del Pulgar, José; Paoletti, Flavio

    2018-02-01

    The volatile profile of crushed rocket leaves (Eruca sativa and Diplotaxis tenuifolia) was investigated by applying Headspace Solid-Phase MicroExtraction (HS-SPME), combined with GC-MS, to an aqueous extract obtained by homogenization of rocket leaves, and stabilized by addition of CaCl2. A detailed picture of volatile products of the lipoxygenase pathway (mainly C6-aldehydes) and of glucosinolate hydrolysis (mainly isothiocyanates), and their dynamics of formation after tissue disruption was given. Odor-active compounds of leaves were characterized by GC-Olfactometry (GC-O) and Aroma Extract Dilution Analysis (AEDA): volatile isolates obtained by HS-SPME from an aqueous extract and by Stir-Bar Sorptive Extraction (SBSE) from an ethanolic extract were analyzed. The most potent odor-active compounds fully or tentatively identified were (Z)- and (E)-3-hexenal, (Z)-1,5-octadien-3-one, responsible for green olfactory notes, along with 4-mercaptobutyl and 4-(methylthio)butyl isothiocyanate, associated with typical rocket and radish aroma. Relatively high odor potency was observed for 1-octen-3-one, (E)-2-octenal and 1-penten-3-one. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Measurements of Low Volatility Organic Compounds (LVOCs) in Aircraft Engine Exhaust

    NASA Astrophysics Data System (ADS)

    Cross, E. S.; Hunter, J. F.; Carrasquillo, A. J.; Daumit, K. E.; Herndon, S. C.; Franklin, J. P.; Miake-Lye, R. C.; Jayne, J.; Worsnop, D. R.; Kroll, J. H.

    2011-12-01

    Gas phase low volatilty organic compounds (LVOCs) comprise an atmospherically important, largely unmeasured class of organic species in the atmosphere. LVOCs consist of intermediate volatility organic compounds (IVOCs; i.e. C13-C20 n-alkanes) and semivolatile organic compunds (SVOCs; i.e. C21-C32 n-alkanes). Atmospheric oxidation of gas phase LVOCs results in the formation of secondary organic aerosol (SOA) which in turn has direct implications for climate and human health. The rates and the chemical properties of LVOC emissions and oxidation products (in the gas phase and particle phase) are poorly characterized and not accurately parameterized in atmospheric chemistry models. This paper will provide an overview of experimental results obtained with a novel technique that provides a volatility-resolved, quantitative measure of LVOCs (and LVOC oxidation products) in the atmosphere. Results from the Alternative Aviation Fuels Experiment (AAFEX-II) conducted at the NASA Dryden Aircraft Operations Facility in April 2011 will be presented. The experiment was designed to characterize the gas phase and particulate emissions from the NASA DC-8 Aircraft as a function of engine power and fuel type. Differences in the desorption profile (i.e. volatility) and chemical characteristics of the LVOC emissions will be highlighted.

  18. Songbird chemosignals: volatile compounds in preen gland secretions vary among individuals, sexes, and populations

    PubMed Central

    Soini, Helena A.; Atwell, Jonathan W.; Hollars, Craig; Novotny, Milos V.; Ketterson, Ellen D.

    2010-01-01

    Chemical signaling has been documented in many animals, but its potential importance in avian species, particularly songbirds, has received far less attention. We tested whether volatile compounds in the preen oil of a songbird (Junco hyemalis) contain reliable information about individual identity, sex, or population of origin by repeated sampling from captive male and female juncos originating from 2 recently diverged junco populations in southern California. One of the populations recently colonized an urban environment; the other resides in a species-typical montane environment. The birds were field-caught as juveniles, housed under identical conditions, and fed the same diet for 10 months prior to sampling. We used capillary gas chromatography–mass spectrometry to quantify the relative abundance of 19 volatile compounds previously shown to vary seasonally in this species. We found individual repeatability as well as significant sex and population differences in volatile profiles. The persistence of population differences in a common environment suggests that preen oil chemistry likely has a genetic basis and may thus evolve rapidly in response to environmental change. These finding suggest that songbird preen oil odors have the potential to function as chemosignals associated with mate recognition or reproductive isolation. PMID:22475692

  19. Urinary volatile organic compounds as potential biomarkers for renal cell carcinoma

    PubMed Central

    WANG, DONGCHUN; WANG, CHANGSONG; PI, XIN; GUO, LEI; WANG, YUE; LI, MINGJUAN; FENG, YUE; LIN, ZIWEI; HOU, WEI; LI, ENYOU

    2016-01-01

    Currently, there is no adequate, sensitive, reproducible, specific and noninvasive biomarker that can reliably be used to detect renal cell carcinoma (RCC). Previous studies have elucidated the urinary non-volatile metabolic profile of RCC. However, whether urinary volatile organic compound (VOC) profiles are able to identify RCC remains to be elucidated. In the present study, urine was collected from 22 patients with RCC and 25 healthy subjects. Principal component analysis and orthogonal partial least square discriminant analysis were used to compare the data of patients and healthy subjects, and preoperative and postoperative patients undergoing radical nephrectomy. In total, 11 VOC biomarkers were elevated in the RCC patients compared to the healthy subjects, which were phenol; decanal; 1,6-dioxacyclododecane-7,12-dione; 1-bromo-1-(3-methyl-1-pentenylidene)-2,2,3,3-tetramethyl-cyclopropane; nonanal; 3-ethyl-3-methylheptane; isolongifolene-5-ol; 2,5-cyclohexadiene-1,4-dione, 2,6-bis(1,1-dimethylethyl); tetradecane; aniline; and 2,6,10,14-tetramethyl-pentadecane. Three biomarkers were decreased in RCC patients: styrene, 4-heptanone and dimethylsilanediol. In preoperative patients, 2-ethyl-1-hexanol and cyclohexanone were elevated, while 6-t-butyl-2,2,9,9-tetramethyl-3,5-decadien-7-yne were decreased when compared to postoperative patients. Compared with the healthy subjects, RCC has a unique VOC profile, suggesting that VOC profiles may be a useful diagnostic assay for RCC. PMID:27347408

  20. Chemical oxidation of volatile and semi-volatile organic compounds in soil

    SciTech Connect

    Gates, D.D.; Siegrist, R.L.; Cline, S.R.

    1995-06-01

    Subsurface contamination with fuel hydrocarbons or chlorinated hydrocarbons is prevalent throughout the Department of Energy (DOE) complex and in many sites managed by the Environmental Protection Agency (EPA) Superfund program. The most commonly reported chlorinated hydrocarbons (occurring > 50% of DOE contaminated sites) were trichloroethylene (TCE), 1, 1, 1,-trichloroethane (TCA), and tetrachloroethylene (PCE) with concentrations in the range of 0.2 {mu}g/kg to 12,000 mg/kg. The fuel hydrocarbons most frequently reported as being present at DOE sites include aromatic compounds and polyaromatic compounds such as phenanthrene, pyrene, and naphthalene. The primary sources of these semi-volatile organic compounds (SVOCs) are coal waste from coal fired electric power plants used at many of these facilities in the past and gasoline spills and leaks. Dense non-aqueous phase liquids (DNAPLs) can migrate within the subsurface for long periods of time along a variety of pathways including fractures, macropores, and micropores. Diffusion of contaminants in the non-aqueous, aqueous, and vapor phase can occur from the fractures and macropores into the matrix of fine-textured media. As a result of these contamination processes, removal of contaminants from the subsurface and the delivery of treatment agents into and throughout contaminated regions are often hindered, making rapid and extensive remediation difficult.

  1. 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

  2. 76 FR 4835 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-27

    ... Organic Compound Reinforced Plastics Composites Production Operations Rule AGENCY: Environmental... control of volatile organic compound (VOC) emissions from reinforced plastic composites production... plastic composites production operations. This rule is approvable because it satisfies the requirements...

  3. 78 FR 55234 - Approval and Promulgation of Implementation Plans; Indiana; Volatile Organic Compound Emission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-10

    ... Compound Emission Control Measures for Industrial Solvent Cleaning for Northwest Indiana AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: On May 29, 2012, the Indiana Department of Environmental Management (IDEM) submitted revisions to its volatile organic compound...

  4. Assessment of volatile profile as potential marker of chilling injury of basil leaves during postharvest storage.

    PubMed

    Cozzolino, Rosaria; Pace, Bernardo; Cefola, Maria; Martignetti, Antonella; Stocchero, Matteo; Fratianni, Florinda; Nazzaro, Filomena; De Giulio, Beatrice

    2016-12-15

    The volatile profile of three sweet basil cultivars, "Italico a foglia larga", "Cammeo" and "Italiano classico", packaged in air at 4 or 12°C until 9days, was monitored by solid phase microextraction with GC-MS. Chilling injury (CI) score and electrolyte leakage were also assessed. In total, 71 volatile organic compounds (VOCs) were identified in the headspace of basil samples. A preliminary principal component analysis highlighted the dominant effect of the cultivar on VOCs profiles. Data analysis by post-transformation of projection to latent structures regression (ptPLS2) clarified the role played by time and temperature of storage. Temperature influenced the emission of volatiles during storage, with much lower total volatile emissions at 4°C compared to 12°C. Finally, a ptPLS2 regression model performed on VOCs and the two CI parameters allowed selection of 10 metabolites inversely correlated to both CI parameters, which can be considered potential markers of CI in basil leaves.

  5. Membrane bioreactor for control of volatile organic compound emissions

    SciTech Connect

    Ergas, S.J.; McGrath, M.S.

    1997-06-01

    A membrane bioreactor system that overcomes many of the limitations of conventional compost biofilters is described. The system utilizes microporous hydrophobic hollow fiber membranes for mass transfer of volatile organic compounds (VOCs) from the gas phase to a microbially active liquid phase. The reactor design provides a high biomass concentration, a method for wasting biomass, and a method for addition of pH buffers, nutrients, cometabolites, and/or other amendments. A theoretical model is developed, describing mass transfer and biodegradation in the membrane bioreactor. Reactor performance was determined in a laboratory scale membrane bioreactor over a range of gas loading rates using toluene as a model VOC. Toluene removal efficiency was greater than 98% at an inlet concentration of 100 ppm, and a gas residence time of less than 2 s. Factors controlling bioreactor performance were determined through both experiments and theoretical modeling to include: compound Henry`s law constant, membrane specific surface area, gas and VOC loading rates, liquid phase turbulence, and biomass substrate utilization rate.

  6. Volatile organic compounds in storm water from a parking lot

    USGS Publications Warehouse

    Lopes, T.J.; Fallon, J.D.; Rutherford, D.W.; Hiatt, M.H.

    2000-01-01

    A mass balance approach was used to determine the most important nonpoint source of volatile organic compounds (VOCs) in storm water from an asphalt parking lot without obvious point sources (e.g., gasoline stations). The parking lot surface and atmosphere are important nonpoint sources of VOCs, with each being important for different VOCs. The atmosphere is an important source of soluble, oxygenated VOCs (e.g., acetone), and the parking lot surface is an important source for the more hydrophobic VOCs (e.g., benzene). VOCs on the parking lot surface appear to be concentrated in oil and grease and organic material in urban particles (e.g., vehicle soot). Except in the case of spills, asphalt does not appear to be an important source of VOCs. The uptake isotherm of gaseous methyl tert-butyl ether on urban particles indicates a mechanism for dry deposition of VOCs from the atmosphere. This study demonstrated that a mass balance approach is a useful means of understanding non-point-source pollution, even for compounds such as VOCs, which are difficult to sample.

  7. Volatile organic compounds in fourteen U.S. retail stores.

    PubMed

    Nirlo, E L; Crain, N; Corsi, R L; Siegel, J A

    2014-10-01

    Retail buildings have a potential for both short-term (customer) and long-term (occupational) exposure to indoor pollutants. However, little is known about volatile organic compound (VOC) concentrations in the retail sector and influencing factors, such as ventilation, in-store activities, and store type. We measured VOC concentrations and ventilation rates in 14 retail stores in Texas and Pennsylvania. With the exception of formaldehyde and acetaldehyde, VOCs were present in retail stores at concentrations well below health guidelines. Indoor formaldehyde concentrations ranged from 4.6 ppb to 67 ppb. The two mid-sized grocery stores in the sample had the highest levels of ethanol and acetaldehyde, with concentrations up to 2.6 ppm and 92 ppb, respectively, possibly due to the preparation of dough and baking activities. Indoor-to-outdoor concentration ratios indicated that indoor sources were the main contributors to indoor VOC concentrations for the majority of compounds. There was no strong correlation between ventilation and VOC concentrations across all stores. However, increasing the air exchange rates at two stores led to lower indoor VOC concentrations, suggesting that ventilation can be used to reduce concentrations for some specific stores. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Indoor carpet as an adsorptive reservoir for volatile organic compounds

    SciTech Connect

    Won, D.; Corsi, R.L.; Rynes, M.

    1999-07-01

    Carpet is recognized as a potential source of volatile organic compounds (VOCs) in indoor air. However, carpet systems can also serve as adsorptive sinks with the potential for reductions in peak VOC concentrations and subsequent re-emission of VOCs over prolonged periods of time. A series of experiments involving eight VOCs, and several carpet systems and environmental conditions were completed using a set of parallel chambers to characterize carpet systems as sinks of VOCs. A linear adsorption and desorption model was used to describe interactions between VOCs and carpet. New carpet fibers treated with stain protection generally accounted for only a very small fraction of mass sorbed to carpet. Most of the sorbed mass for carpet systems was accounted for by either the underlying pad or a combination of the pad and structural backing. Methyl-tert-butyl ether (MTBE) was the only compound to exhibit greater sorption to nylon fibers than to other carpet components. Vapor pressure was observed to be one of the properties that can be related to sorption parameters. Variations in relative humidity (RH) had a significant effect on the degree of sorption for a highly soluble VOC (isopropanol). However, RH had no apparent effect on other VOCs. Air exchange rates (0.5, 2.1, 3.2 /hr) and inlet concentrations (2.5, 5, 15 ppm) generally had little effect on sorption.

  9. 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.

  10. Volatile organic compounds in foods: a five year study.

    PubMed

    Fleming-Jones, Mary Ellen; Smith, Robert E

    2003-12-31

    A purge and trap procedure was used with gas chromatography-mass spectrometry determination to analyze 70 foods for volatile organic compounds (VOCs). The results from analyses over a 5 year period (1996-2000) are reported. VOCs were found in at least one sample of all foods tested, although no single compound was found in each of the foods. The total amount of VOCs found in a single food item over the 5 year period ranged from 24 to 5328 ppb, with creamed corn (canned) the lowest and cheddar cheese the highest. Benzene was found in all foods except American cheese and vanilla ice cream. Benzene levels ranged from 1 to 190 ppb, with the highest level found in fully cooked ground beef. Benzene was found in 12 samples of cooked ground beef, with an average of 40 ppb. Benzene levels above 100 ppb were also seen in at least one sample each of a cola (138 ppb), raw bananas (132 ppb), and cole slaw (102 ppb). This compares to a maximum contaminant level of 5 ppb set by the U.S. EPA for drinking water.

  11. Novel collection method for volatile organic compounds (VOCs) from dogs.

    PubMed

    Holderman, Chris J; Kaufman, Phillip E; Booth, Matthew M; Bernier, Ulrich R

    2017-09-01

    Host derived chemical cues are an important aspect of arthropod attraction to potential hosts. Host cues that act over longer distances include CO2, heat, and water vapor, while cues such as volatile organic compounds (VOCs) act over closer distances. Domestic dogs are important hosts for disease cycles that include dog heartworm disease vectored by mosquitoes, however the host VOCs utilized by vectors are not well known. Herein we present a novel method that sampled VOCs from a dog host. A Tenax TD stainless steel tube was held near a dog's fur and skin, which collected VOCs that were later desorbed and tentatively identified using a gas chromatograph-mass spectrospectrometer (GC-MS). Background air chemicals were subtracted from the dog sample, resulting in 182 differentiated compounds, a majority of which were identified by ionization fragmentation patterns. Four dogs were sampled and shared 41 of the identified chemicals. VOCs were representative of aliphatics, aromatics, aldehydes, alcohols and carboxylic acids. This chemical characterization method has the potential to identify both individuals and breeds of dogs in addition to other potential uses such as disease diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Evaluation of the volatile profile of 33 Pyrus ussuriensis cultivars by HS-SPME with GC-MS.

    PubMed

    Qin, Gaihua; Tao, Shutian; Cao, Yufen; Wu, Juyou; Zhang, Huping; Huang, Wenjiang; Zhang, Shaoling

    2012-10-15

    Evaluation of the volatile compounds in fruit provides useful information for plant breeding for improved fruit aroma. In this study, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to assess the volatile profile of 33 cultivars of the Chinese pear Pyrus ussuriensis. In all, 108 volatile compounds were identified and there were significant differences in the composition and concentration of volatiles among cultivars. On the basis of principal components analysis (PCA), the cultivars could be divided into four groups: Group 1 contained Reli, Jinxiang, Hongbalixiang, Baibalixiang and Fuwuxiang, cultivars with a high concentration of esters and a low concentration of hydrocarbons. Group 2 contained Qiuxiang, Fuanjianba, Longxiang, Guanhongxiao, Shanli24 and Wuxiangli, cultivars with high concentrations of hydrocarbons and low concentrations of esters. Group 3 contained Shatangli and Manyuanxiang, cultivars with high concentrations of aldehydes. Group 4 contained the other 25 cultivars. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Novel vinegar-derived product enriched with dietary fiber: effect on polyphenolic profile, volatile composition and sensory analysis.

    PubMed

    Marrufo-Curtido, Almudena; Cejudo-Bastante, María Jesús; Rodríguez-Dodero, M Carmen; Natera-Marín, Ramón; Castro-Mejías, Remedios; García-Barroso, Carmelo; Durán-Guerrero, Enrique

    2015-12-01

    Dietary fiber derived from citrus fruits was added to vinegar. Different sources and quantities of fiber and storage conditions have been scrutinized. Formulated vinegars were evaluated on the basis of their phenolic profile, volatile composition and sensory analysis. The addition of citrus fiber enhanced the phenolic and volatile profile of the resulted vinegars. Whereas lemon fiber contributed mostly to the enrichment of the polyphenolic composition, orange fiber was that which increased in a higher way the volatile composition of the vinegars. Moreover, the content of hydroxycinnamic acid derivatives and the majority of volatile compounds decreased as the dose of fiber increased. Furthermore, the judges preferred fiber-enriched vinegars, but in different quantities depending of the fiber source. This preference was mainly based on citric attribute, contributing several terpenes and ketones derived from them. The addition of citrus fiber to vinegar did not result in a marked storage-dependence.

  14. 2nd dimensional GC-MS analysis of sweat volatile organic compounds prepared by solid phase micro-extraction.

    PubMed

    Choi, Mi-Jung; Oh, Chang-Hwan

    2014-01-01

    The characteristics of an individual's odor from sweat, breath and skin provide important information for criminal tracking in field of forensic science. Solid phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS) was used to determine human sweat volatile organic compounds (VOCs) profiles. The mass spectrometric analysis (with electron impact mode) followed by 2nd dimensional separation with two different GC columns (one polar and one relatively nonpolar) connected in parallel were used to identify the 574 compounds from sweat samples. The components included alcohols, aldehydes, aliphatics/aromatics, carboxylic acids, esters, ketones, and other organic compounds (amides/amines, thio/thioesters, oxide, sulfides, nitro compounds). Of these compounds, 1-tridecanol, 1,3-bis(1,1-dimethyl ethyl)-benzene, 4,4'-(1-methylethylidene) bis-phenol and 7-acetyl-6-ethyl-1,1,4,4,-tetramethyl-tetraline were common components in all donor's sweat volatile samples. Age-related specific compounds were also detected. The results suggest that characteristic volatile profiles of human sweat emanations could provide the valuable information to forensic scientists.

  15. ESTIMATING TRANSPORT AND DEPOSITION OF A SEMI-VOLATILE COMPOUND WITH A REGIONAL PHOTOCHEMICAL MODEL

    EPA Science Inventory

    To simulate the fate of compounds that are considered semi-volatile and toxic, we have modified a model for regional particulate matter. Our changes introduce a semi-volatile compound into the atmosphere as gaseous emissions from an area source. Once emitted, the gas can transf...

  16. 40 CFR 60.542a - Alternate standard for volatile organic compounds.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a)...

  17. 40 CFR 60.312 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Surface Coating of Metal Furniture § 60.312 Standard for volatile organic compounds (VOC). (a) On...

  18. 40 CFR 60.112 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... After June 11, 1973, and Prior to May 19, 1978 § 60.112 Standard for volatile organic compounds...

  19. 40 CFR 60.112 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... After June 11, 1973, and Prior to May 19, 1978 § 60.112 Standard for volatile organic compounds...

  20. 40 CFR 60.112b - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds... for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which... organic compounds (VOC). (a) The owner or operator of each storage vessel either with a design...

  1. 40 CFR 60.112 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... After June 11, 1973, and Prior to May 19, 1978 § 60.112 Standard for volatile organic compounds...

  2. 40 CFR 60.542a - Alternate standard for volatile organic compounds.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a)...

  3. 40 CFR 60.112 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... After June 11, 1973, and Prior to May 19, 1978 § 60.112 Standard for volatile organic compounds...

  4. 40 CFR 60.312 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Surface Coating of Metal Furniture § 60.312 Standard for volatile organic compounds (VOC). (a) On...

  5. 40 CFR 60.312 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Surface Coating of Metal Furniture § 60.312 Standard for volatile organic compounds (VOC). (a) On...

  6. 40 CFR 60.542a - Alternate standard for volatile organic compounds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a)...

  7. 75 FR 57390 - Approval and Promulgation of Implementation Plans; Alabama: Volatile Organic Compounds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Implementation Plans; Alabama: Volatile Organic... definition of ``volatile organic compounds'' (VOCs) found at Alabama Administrative Code (AAC) section 335-3... organic compounds) have different levels of reactivity; they do not react at the same speed, or do...

  8. 40 CFR 60.112b - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds... for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which... organic compounds (VOC). (a) The owner or operator of each storage vessel either with a design...

  9. 40 CFR 60.542a - Alternate standard for volatile organic compounds.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a)...

  10. 40 CFR 60.542a - Alternate standard for volatile organic compounds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a)...

  11. 40 CFR 60.112b - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds... for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which... organic compounds (VOC). (a) The owner or operator of each storage vessel either with a design...

  12. 40 CFR 60.112b - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds... for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which... organic compounds (VOC). (a) The owner or operator of each storage vessel either with a design...

  13. 40 CFR 60.312 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Surface Coating of Metal Furniture § 60.312 Standard for volatile organic compounds (VOC). (a) On...

  14. 40 CFR 60.312 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Surface Coating of Metal Furniture § 60.312 Standard for volatile organic compounds (VOC). (a) On...

  15. 40 CFR 60.112 - Standard for volatile organic compounds (VOC).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... After June 11, 1973, and Prior to May 19, 1978 § 60.112 Standard for volatile organic compounds...

  16. ESTIMATING TRANSPORT AND DEPOSITION OF A SEMI-VOLATILE COMPOUND WITH A REGIONAL PHOTOCHEMICAL MODEL

    EPA Science Inventory

    To simulate the fate of compounds that are considered semi-volatile and toxic, we have modified a model for regional particulate matter. Our changes introduce a semi-volatile compound into the atmosphere as gaseous emissions from an area source. Once emitted, the gas can transf...

  17. A survey of household products for volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Sack, Thomas M.; Steele, David H.; Hammerstrom, Karen; Remmers, Janet

    A total of 1159 common household products were analysed for 31 volatile organic compounds as potential sources of indoor air pollution. The products were distributed among 65 product categories within 8 category classes: automotive products (14.4% of the products); household cleaners/polishes (9.6%); paint-related products (39.9%); fabric and leather treatments (7.9%); cleaners for electronic equipment (6.0%); oils, greases and lubricants (9.6%); adhesive-related products (6.6%); and miscellaneous products (6.1%). The study was conducted in two parts. In the first part, or the original study, the products were reanalysed for methylene chloride and five other chlorocarbons using purge-and-trap gas chromatography/mass spectrometry (GC/MS), and a data base containing the analytical results was developed. Because full mass spectra were taken, the original set of GC/MS data also contained information regarding other volatile chemicals in the products. However, this additional data was not reported at that time. In the second part of the study, the GC/MS data were reanalysed to determine the presence and concentrations of an additional 25 volatile chemicals. The 31 chemicals included in both parts of this study were: carbon tetrachloride; methylene chloride; tetrachloroethylene; 1,1,1-trichloroethane; trichlorethylene; 1,1,2-tricholorotrifluoroethane; acetone; benzene; 2-butanone; chlorobenzene; chloroform; cyclohexane; 1,2-dichloroethane; 1,4-dioxane; ethylbenzene; n-hexane; d-limonene; methylcyclohexane; methylcyclopentane; methyl isobutyl ketone; n-nonane; n-octane; α-pinene; propylene oxide; styrene; 1,1,2,2-tetrachloroethane; tetrahydrofuran; toluene; m-mxylene; o-xylene; and p-xylene. Of the 31 chemicals, toluene, the xylenes and methylene chloride were found to occur most frequently—in over 40% of the products tested. Chemicals that were typically found in relatively high concentrations in the samples (i.e. greater than 20% w/w) included acetone, 2-butanone

  18. Changes in the profile of volatiles of canned coconut milk during storage.

    PubMed

    Tinchan, Patcharaporn; Lorjaroenphon, Yaowapa; Cadwallader, Keith R; Chaiseri, Siree

    2015-01-01

    The alteration of the profile of volatiles of canned coconut milk was monitored during storage at ambient temperature. Canned coconut milk was thermally processed (121 °C for 5 min), and then stored at ambient temperature (32 to 35 °C) for 6 mo. Volatile compounds were assessed monthly using direct solvent extraction (diethyl ether), followed by high-vacuum distillation and gas chromatography-mass spectrometry analysis. Six groups of compounds consisting of alcohols, aldehydes, ketones, acids, esters, lactones, and others were identified. Two stages of major changes in profile of volatiles were observed. The 1st occurred after 2 mo as indicated by a high abundance of alcohols, acids, and lactones. The 2nd was observed after 5 mo and corresponded to a large increase in lactones, short-chain free fatty acids, 3-methyl-2(5H)-furanone, and phenol. Acetic and butyric acids observed after 5 mo could contribute to the potential of off-odor development in the product as indicated by their high odor activity values. Lactones increased approximately 10-fold. Identification of 3-methyl-2(5H)-furanone indicated that Maillard reaction had occurred in conjunction with the development of a coconut, toffee-like, and caramel odor.

  19. Multiple microbial activities for volatile organic compounds reduction by biofiltration.

    PubMed

    Civilini, Marcello

    2006-07-01

    In the northeast of Italy, high volatile organic carbon (VOC) emissions originate from small-medium companies producing furniture. In these conditions it is difficult to propose a single, efficient, and economic system to reduce pollution. Among the various choices, the biofiltration method could be a good solution, because microbial populations possess multiple VOC degradation potentials used to oxidize these compounds to CO2. Starting from the air emissions of a typical industrial wood-painting plant, a series of experiments studied in vitro microbial degradation of each individual VOC. Isolated strains were then added to a laboratory-scale biofiltration apparatus filled with an organic matrix, and the different VOC behavior demonstrated the potential of single and/or synergic microbial removal actions. When a single substrate was fed, the removal efficiency of a Pseudomonas aeruginosa inoculated reactor was 1.1, 1.17, and 0.33 g m(-3) hr(-1), respectively, for xylene, toluene, and ethoxy propyl acetate. A VOC mixture composed of butyl acetate, ethyl acetate, diacetin alcohol, ethoxy propanol acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene was then fed into a 2-m(3) reactor treating 100 m3 hr(-1) of contaminated air. The reactor was filled with the same mixture of organic matrix, enriched with all of the isolated strains together. During reactor study, different VOC loading rates were used, and the behavior was evaluated continuously. After a short acclimation period, the removal efficiency was > 65% at VOC load of 150-200 g m(-3) hr(-1). Quantification of removal efficiencies and VOC speciation confirmed the relationship among removal efficiencies, compound biodegradability, and the dynamic transport of each mixture component within the organic matrix. Samples of the fixed bed were withdrawn at different intervals and the heterogeneous microbial community evaluated for both total and differential compound counts.

  20. Changes of volatile compounds during heating of bacuri pulp.

    PubMed

    Boulanger, R; Crouzet, J

    2001-12-01

    The formation of volatile compounds from precursors or through chemical rearrangement during heat treatment of bacuri pulp at fruit natural pH were studied using simultaneous distillation/extraction (SDE) technique. An increase of the quantities of oxygenated and hydrocarbon terpenes and, to a lesser degree, aldehydes, was observed after SDE at pH 3, relative to the other extraction methods used, SDE at neutral pH and solid phase extraction (SPE). More particularly, linalool, linalool furanoxides, alpha-terpineol, hotrienol, nerol oxide, nerol, and geraniol were isolated in more important quantities after the first treatment than after the others. These results can be partially explained by the hydrolysis of glycosidically bound compounds previously identified in bacuri. Other pathways such as polyol rearrangements were also involved. The formation of linalool and alpha-terpineol was probably the result of the rearrangement of 2,6-dimethyloct-1-ene-3,7-diol. Moreover, it was assumed that oxidation reactions occurred during SDE at pH 3; more particularly, linalool pyranoxides partially resulted from nonenzymatic oxidation of linalool. When SDE was performed at pH 3, an increase of furfural and 4-methoxy-2,5-dimethyl-3(2H)-furanone was noticed. The modifications of the concentration of aliphatic aldehydes, known as lipid oxidation compounds, and of fatty acid esters were in good agreement with the observed decrease of palmitic and linoleic acid concentrations during this treatment. Moreover, important amounts of 2-acetyl-1-pyrroline were found in the SDE extract recovered at pH 7.

  1. Emission of volatile sulfur compounds from spruce trees

    SciTech Connect

    Rennenberg, H.; Huber, B.; Schroeder, P.; Stahl, K.; Haunold, W.; Georgil, H.W.; Slovik, S.; Pfanz, H. )

    1990-03-01

    Spruce (Picea abies L.) trees from the same clone were supplied with different, but low, amounts of plant available sulfate in the soil (9.7-18.1 milligrams per 100 grams of soil). Branches attached to the trees were enclosed in a dynamic gas exchange cuvette and analyzed for the emission of volatile sulfur compounds. Independent of the sulfate supply in the soil, H{sub 2}S was the predominant reduced sulfur compound continuously emitted from the branches with high rates during the day and low rates in the night. In the light, as well as in the dark, the rates of H{sub 2}S emission increased exponentially with increasing water vapor flux from the needles. Approximately 1 nanomole of H{sub 2}S was found to be emitted per mole of water. When stomata were closed completely, only minute emission of H{sub 2}S was observed. Apparently, H{sub 2}S emission from the needles is highly dependent on stromatal aperture, and permeation through the cuticle is negligible. In several experiments, small amounts of dimethylsulfide and carbonylsulfide were also detected in a portion of the samples. However, SO{sub 2} was the only sulfur compound consistently emitted from branches of spruce trees in addition to H{sub 2}S. Emission of SO{sub 2} mainly proceeded via an outburst starting before the beginning of the light period. The total amount of SO{sub 2} emitted from the needles during this outburst was correlated with the plant available sulfate in the soil. The diurnal changes in sulfur metabolism that may result in an outburst of SO{sub 2} are discussed.

  2. In vitro determination of volatile compound development during starter culture-controlled fermentation of Cucurbitaceae cotyledons.

    PubMed

    Kamda, Aristide Guillaume Silapeux; Ramos, Cíntia Lacerda; Fokou, Elie; Duarte, Whasley Ferreira; Mercy, Achu; Germain, Kansci; Dias, Disney Ribeiro; Schwan, Rosane Freitas

    2015-01-02

    The effects of Lactobacillus plantarum UFLA CH3, Pediococcus acidilactici UFLA BFFCX 27.1, and Torulaspora delbrueckii UFLA FFT2.4 inoculation on the volatile compound profile of fermentation of Cucumeropsis mannii cotyledons were investigated. Different microbial associations were used as starters. All associations displayed the ability to ferment the cotyledons as judged by lowering the pH from 6.4 to 4.4-5 within 24h and increasing organic acids such as lactate and acetate. The population of lactic acid bacteria (LAB) and yeasts increased during fermentation. In the fermentation performed without inoculation (control), the LAB and yeast populations were lower than those in inoculated assays at the beginning, but they reached similar populations after 48 h. The Enterobacteriaceae population decreased during the fermentation, and they were not detected at 48 h in the L. plantarum UFLA CH3 and P. acidilactici UFLA BFFCX 27.1 (LP+PA) and L. plantarum UFLA CH3, P. acidilactici UFLA BFFCX 27.1, and T. delbrueckii UFLA FFT2.4 (LP+PA+TD) samples. The assays inoculated with the yeast T. delbrueckii UFLA FFT2.4 exhibited the majority of volatile compounds (13 compounds) characterized by pleasant notes. The LP+PA+TD association seemed to be appropriate to ferment C. mannii cotyledons. It was able to control the Enterobacteriaceae population, and achieved high concentrations of esters and low concentrations of aldehydes and ketones. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Characterisation of bound volatile compounds of a low flavour kiwifruit species: Actinidia eriantha.

    PubMed

    Garcia, Coralia V; Quek, Siew-Young; Stevenson, Ralph J; Winz, Robert A

    2012-09-15

    Aroma compounds in fruit are known to occur in free and glycosidically bound forms. The bound volatile fraction of a low flavour kiwifruit species, Actinidia eriantha, was studied. The fruit have a bland and grassy flavour. Glycosidic precursors were isolated from juice by adsorption onto an Amberlite XAD-2 column. After enzymatic hydrolysis with Rapidase AR2000, the released aglycones were analysed by GC-MS. Alcohols, terpenoids and phenolics were the most numerously represented compound classes. Alcohols, benzenoids and phenolics showed the highest concentrations. Major compounds were 2-phenylethanol, furfuryl alcohol, (Z)-3-hexen-1-ol, coniferyl alcohol, isoamyl alcohol and linolenic acid. Several of the bound compounds found, including linoleic, linolenic and benzoic acids and coniferyl alcohol, are precursors of odorous volatiles. Many compounds detected as bound volatiles have not been previously reported as free volatiles in A. eriantha. The bound volatile composition of A. eriantha also showed differences with those of other kiwifruit species.

  4. Comparison of receptor models for source apportionment of volatile organic compounds in Beijing, China.

    PubMed

    Song, Yu; Dai, Wei; Shao, Min; Liu, Ying; Lu, Sihua; Kuster, William; Goldan, Paul

    2008-11-01

    Identifying the sources of volatile organic compounds (VOCs) is key to reducing ground-level ozone and secondary organic aerosols (SOAs). Several receptor models have been developed to apportion sources, but an intercomparison of these models had not been performed for VOCs in China. In the present study, we compared VOC sources based on chemical mass balance (CMB), UNMIX, and positive matrix factorization (PMF) models. Gasoline-related sources, petrochemical production, and liquefied petroleum gas (LPG) were identified by all three models as the major contributors, with UNMIX and PMF producing quite similar results. The contributions of gasoline-related sources and LPG estimated by the CMB model were higher, and petrochemical emissions were lower than in the UNMIX and PMF results, possibly because the VOC profiles used in the CMB model were for fresh emissions and the profiles extracted from ambient measurements by the two-factor analysis models were "aged".

  5. Source apportionment modeling of volatile organic compounds in streams

    USGS Publications Warehouse

    Pankow, J.F.; Asher, W.E.; Zogorski, J.S.

    2006-01-01

    It often is of interest to understand the relative importance of the different sources contributing to the concentration cw of a contaminant in a stream; the portions related to sources 1, 2, 3, etc. are denoted cw,1, cw,2, cw,3, etc. Like c w, 'he fractions ??1, = cw,1/c w, ??2 = cw,2/cw, ??3 = cw,3/cw, etc. depend on location and time. Volatile organic compounds (VOCs) can undergo absorption from the atmosphere into stream water or loss from stream water to the atmosphere, causing complexities affecting the source apportionment (SA) of VOCs in streams. Two SA rules are elaborated. Rule 1: VOC entering a stream across the air/water interface exclusively is assigned to the atmospheric portion of cw. Rule 2: VOC loss by volatilization, flow loss to groundwater, in-stream degradation, etc. is distributed over cw,1 cw,2, c w,3, etc. in proportion to their corresponding ?? values. How the two SA rules are applied, as well as the nature of the SA output for a given case, will depend on whether transport across the air/water interface is handled using the net flux F convention or using the individual fluxes J convention. Four hypothetical stream cases involving acetone, methyl-tert-butyl ether (MTBE), benzene, chloroform, and perchloroethylene (PCE) are considered. Acetone and MTBE are sufficiently water soluble from air for a domestic atmospheric source to be capable of yielding cw values approaching the common water quality guideline range of 1 to 10 ??g/L. For most other VOCs, such levels cause net outgassing (F > 0). When F > 0 in a given section of stream, in the net flux convention, all of the ??j, for the compound remain unchanged over that section while cw decreases. A characteristic time ??d can be calculated to predict when there will be differences between SA results obtained by the net flux convention versus the individual fluxes convention. Source apportionment modeling provides the framework necessary for comparing different strategies for mitigating

  6. Volatile profile of Madeira wines submitted to traditional accelerated ageing.

    PubMed

    Pereira, Vanda; Cacho, Juan; Marques, José C

    2014-11-01

    The evolution of monovarietal fortified Madeira wines forced-aged by traditional thermal processing (estufagem) were studied in terms of volatiles. SPE extracts were analysed by GC-MS before and after heating at 45 °C for 3 months (standard) and at 70 °C for 1 month (overheating). One hundred and ninety volatile compounds were identified, 53 of which were only encountered in baked wines. Most chemical families increased after standard heating, especially furans and esters, up to 61 and 3-fold, respectively. On the contrary, alcohols, acetates and fatty acids decreased after heating. Varietal aromas, such as Malvasia's monoterpenic alcohols were not detected after baking. The accelerated ageing favoured the development of some volatiles previously reported as typical aromas of finest Madeira wines, particularly phenylacetaldeyde, β-damascenone and 5-ethoxymethylfurfural. Additionally, ethyl butyrate, ethyl 2-methylbutyrate, ethyl caproate, ethyl isovalerate, guaiacol, 5-hydroxymethylfurfural and γ-decalactone were also found as potential contributors to the global aroma of baked wines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Volatile compound-mediated interactions between barley and pathogenic fungi in the soil.

    PubMed

    Fiers, Marie; Lognay, Georges; Fauconnier, Marie-Laure; Jijakli, M Haïssam

    2013-01-01

    Plants are able to interact with their environment by emitting volatile organic compounds. We investigated the volatile interactions that take place below ground between barley roots and two pathogenic fungi, Cochliobolus sativus and Fusarium culmorum. The volatile molecules emitted by each fungus, by non-infected barley roots and by barley roots infected with one of the fungi or the two of them were extracted by head-space solid phase micro extraction and analyzed by gas chromatography mass spectrometry. The effect of fungal volatiles on barley growth and the effect of barley root volatiles on fungal growth were assessed by cultivating both organisms in a shared atmosphere without any physical contact. The results show that volatile organic compounds, especially terpenes, are newly emitted during the interaction between fungi and barley roots. The volatile molecules released by non-infected barley roots did not significantly affect fungal growth, whereas the volatile molecules released by pathogenic fungi decreased the length of barley roots by 19 to 21.5% and the surface of aerial parts by 15%. The spectrum of the volatiles released by infected barley roots had no significant effect on F. culmorum growth, but decreased C. sativus growth by 13 to 17%. This paper identifies the volatile organic compounds emitted by two pathogenic fungi and shows that pathogenic fungi can modify volatile emission by infected plants. Our results open promising perspectives concerning the biological control of edaphic diseases.

  9. Maximizing Information from Residential Measurements of Volatile Organic Compounds

    SciTech Connect

    Maddalena, Randy; Li, Na; Hodgson, Alfred; Offermann, Francis; Singer, Brett

    2013-02-01

    Continually changing materials used in home construction and finishing can introduce new chemicals or changes in the VOC profile in residential air and the trend towards tighter homes can lead to higher exposure concentrations for many indoor sources. However, the complex mixture of VOCs in residential air makes it difficult to discover emerging contaminants and/or trends in pollutant profiles. The purpose of this study is to prepare a comprehensive library of chemicals found in homes, along with a semi-quantitative approach to maximize the information gained from VOC measurements. We carefully reviewed data from 108 new California homes and identified 238 individual compounds. The majority of the identified VOCs originated indoors. Only 31% were found to have relevant health based exposure guidelines and less than 10% had a chronic reference exposure level (CREL). The finding highlights the importance of extending IAQ studies to include a wider range of VOCs

  10. Analysis of biogenic volatile organic compounds in zucchini flowers: identification of scent sources.

    PubMed

    Mena Granero, A; Egea Gonzalez, F J; Guerra Sanz, J M; Martínez Vidal, J L

    2005-10-01

    An analytical method has been applied to determine volatile organic compounds in zucchini flowers. In a first step, the analytical method was applied to characterize the main scents emitted by whole male and female living flowers of three main commercial cultivars of zucchini (Tosca, Chapin, and Consul). In a second step, the compounds were quantified in different parts of the living flowers to identify the contribution of nectar, petals, anther, and stigma to the aroma profile of the flower. The analytical method is based on headspace solid-phase microextraction coupled on-line with GC and tandem MS detection (HS-SPME-GC-MS/MS). A reference compound is added to samples as part of the field quality control procedure to check for likely analyte losses or sample decomposition. The reference compound also acts as an internal standard for quantification purposes. Results have been statistically studied applying principal component analysis (PCA), which shows that three components explain more than 91% of the variance. PCA emphasizes the great importance of nectar as being the main source of 1,4-dimethoxybenzene and 1,2,4-trimethoxybenzene, which influence the aroma profile of flowers. The remaining components can be accounted for by emissions from petals and sexual organs (adroecium and gynoecium anthers or stigmas).

  11. Characterisation of free and bound volatile compounds from six different varieties of citrus fruits.

    PubMed

    Ren, Jing-Nan; Tai, Ya-Nan; Dong, Man; Shao, Jin-Hui; Yang, Shu-Zhen; Pan, Si-Yi; Fan, Gang

    2015-10-15

    Free volatile compounds in six varieties of citrus juices were analyzed by solid-phase microextraction-gas chromatography-mass spectrometry. Bound fractions were isolated and extracted with methanol and Amberlite XAD-2 resin and then hydrolyzed by almond β-glucosidase. A total of 43 free and 17 bound volatile compounds were identified in citrus. Free volatile contents in sweet orange were the most abundant, followed by those in grapefruits and mandarins. Among free volatiles, terpenes were the most abundant in citrus juice. Sensory analysis results showed that the flavor of the same citrus cultivars was similar, but the flavor of different cultivars varied. Among bound volatiles, benzenic compounds were the most abundant in these citrus juices. Bound volatiles also significantly differed among cultivars. In addition, only p-vinylguaiacol were detected in all of the samples.

  12. Potential using of infrared thermal imaging to detect volatile compounds released from decayed grapes

    PubMed Central

    Ding, Luyu; Jiao, Leizi; Zheng, Wengang

    2017-01-01

    Previous studies have demonstrated variations in volatile compound content during fruit spoilage. Infrared spectroscopy was proposed as an alternative method to discriminate the various states of decayed fruit through the makeup of their volatile compounds. Based on the infrared spectra of volatile compounds obtained from decayed grapes, this study simplified the extraction of their feature spectra and visualized their gas plumes by using a commercial infrared thermal camera equipped with a custom-made wavelength filter. As a function of volatilization gradients, accumulated gray value and imaging area were proposed as indicators for semi-quantitative analysis in a volatilization range similar to that of ethanol solutions ranging from 10% to 70%. Fresh, seriously decayed, and slightly or moderately decayed grapes were rapidly discriminated through their alcoholic volatiles by thermal images with correct classification ratings of 100%, 93.3%, and 90%, respectively. PMID:28665984

  13. Determination of Volatile Compounds in Four Commercial Samples of Japanese Green Algae Using Solid Phase Microextraction Gas Chromatography Mass Spectrometry

    PubMed Central

    Yoshikawa, Keisuke; Fujita, Akira; Mase, Nobuyuki; Watanabe, Naoharu

    2014-01-01

    Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS), has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera), Tokushima (Ulva prolifera), and Ehime prefecture (Ulva linza). Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera) and Tokushima prefecture (Ulva prolifera). Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum). Multivariant statistical analysis (PCA) enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings. PMID:24592162

  14. Determination of volatile compounds in four commercial samples of Japanese green algae using solid phase microextraction gas chromatography mass spectrometry.

    PubMed

    Yamamoto, Masayoshi; Baldermann, Susanne; Yoshikawa, Keisuke; Fujita, Akira; Mase, Nobuyuki; Watanabe, Naoharu

    2014-01-01

    Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS), has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera), Tokushima (Ulva prolifera), and Ehime prefecture (Ulva linza). Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera) and Tokushima prefecture (Ulva prolifera). Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum). Multivariant statistical analysis (PCA) enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings.

  15. Growth and volatile compound production by Brettanomyces/Dekkera bruxellensis in red wine.

    PubMed

    Romano, A; Perello, M C; de Revel, G; Lonvaud-Funel, A

    2008-06-01

    Brettanomyces/Dekkera bruxellensis is a particularly troublesome wine spoilage yeast. This work was aimed at characterizing its behaviour in terms of growth and volatile compound production in red wine. Sterile red wines were inoculated with 5 x 10(3) viable cells ml(-1) of three B. bruxellensis strains and growth and volatile phenol production were followed for 1 month by means of plate counts and gas chromatography-mass spectrometry (GC-MS) respectively. Maximum population levels generally attained 10(6)-10(7) colony forming units (CFU) ml(-1) and volatile phenol concentrations ranged from 500 to 4000 microg l(-1). Brettanomyces bruxellensis multiplication was also accompanied by the production of organic acids (from C(2) to C(10)), short chain acid ethyl-esters and the 'mousy off-flavour' component 2-acetyl-tetrahydropyridine. Different kinds of 'Brett character' characterized by distinct metabolic and sensory profiles can arise in wine depending on the contaminating strain, wine pH and sugar content and the winemaking stage at which contamination occurs. We identified new chemical markers that indicate wine defects caused by B. bruxellensis. Further insight was provided into the role of some environmental conditions in promoting wine spoilage.

  16. Solubility of volatile organic compounds in aqueous ammonia solution.

    PubMed

    Görgényi, Miklós; Dewulf, Jo; Van Langenhove, Herman; Király, Zoltán

    2005-05-01

    The Ostwald solubility coefficient, L of 17 volatile organic compounds (VOCs) from the gas phase into water and dilute aqueous ammonia solutions was determined by the equilibrium partitioning in closed system-solid phase micro extraction (EPICS-SPME) method at 303 K and at 0-2.5 mol dm(-3) ammonia concentrations. Ammonia increased the solubility of all VOCs nearly linearly, but to a different extent. The difference in the solubility values in aqueous ammonia solutions (Lmix) compared to pure water (L) is explained on the basis of a Linear Solvation Energy Relationship (LSER) equation made applicable for solvent mixtures, logLmix - logL = x((sNH3 - sH2O)pi2H + (aNH3 - aH2O)Sigma2H + (bNH3 - bH2O)Sigmabeta2H + (vNH3 - VH2O)Vx). sNH3 - sH2O, aNH3 - aH2O, bNH3 - bH2O, vNH3 - vH2O are the differences of solvent parameters, x is the mole fraction, pi2H is the solute dipolarity-polarizability, Sigmaalpha2H is the effective hydrogen bond acidity of the solute, Sigmabeta2H is the effective hydrogen bond basicity of the solute and Vx, the McGowan characteristic volume. The most significant term was v, the phase hydrophobicity. The solubility behavior was explained by the change in structure of the aqueous solution: the presence of ammonia reduces the cavity effect. These findings show that the presence of compounds such as ammonia, frequently observed in environmental waters, especially wastewaters, affect the fugacity of VOCs, having consequences for the environmental partitioning of VOCs and having technical consequences towards wastewater treatment technologies.

  17. Volatile organic silicon compounds: the most undesirable contaminants in biogases.

    PubMed

    Ohannessian, Aurélie; Desjardin, Valérie; Chatain, Vincent; Germain, Patrick

    2008-01-01

    Recently a lot of attention has been focused on volatile organic silicon compounds (VOSiC) present in biogases. They induce costly problems due to silicate formation during biogas combustion in valorisation engine. The cost of converting landfill gas and digester gas into electricity is adversely affected by this undesirable presence. VOSiC in biogases spark off formation of silicate deposits in combustion chambers. They engender abrasion of the inner surfaces leading to serious damage, which causes frequent service interruptions, thus reducing the economic benefit of biogases. It is already known that these VOSiC originate from polydimethylsiloxanes (PDMS) hydrolysis. PDMS (silicones) are used in a wide range of consumer and industrial applications. PDMS are released into the environment through landfills and wastewater treatment plants. There is a lack of knowledge concerning PDMS biodegradation during waste storage. Consequently, understanding PDMS behaviour in landfill cells and in sludge digester is particularly important. In this article, we focused on microbial degradation of PDMS through laboratory experiments. Preliminary test concerning anaerobic biodegradation of various PDMS have been investigated. Results demonstrate that the biotic step has an obvious influence on PDMS biodegradation. IWA Publishing 2008.

  18. 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.

  19. Evolution of Volatile Sulfur Compounds during Wine Fermentation.

    PubMed

    Kinzurik, Matias I; Herbst-Johnstone, Mandy; Gardner, Richard C; Fedrizzi, Bruno

    2015-09-16

    Volatile sulfur compounds (VSCs) play a significant role in the aroma of foods and beverages. With very low sensory thresholds and strong unpleasant aromas, most VSCs are considered to have a negative impact on wine quality. In this study, headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was used to analyze the time course of the biosynthesis of 12 VSCs formed during wine fermentation. Two different strains of Saccharomyces cerevisiae, the laboratory strain BY4743 and a commercial strain, F15, were assessed using two media: synthetic grape media and Sauvignon Blanc juice. Seven VSCs were detected above background, with three rising above their sensory thresholds. The data revealed remarkable differences in the timing and evolution of production during fermentation, with a transient spike in methanethiol production early during anaerobic growth. Heavier VSCs such as benzothiazole and S-ethyl thioacetate were produced at a steady rate throughout grape juice fermentation, whereas others, such as diethyl sulfide, appear toward the very end of the winemaking process. The results also demonstrate significant differences between yeast strains and fermentation media.

  20. Production of volatile organic compounds by cyanobacteria Synechococcus sp.

    NASA Astrophysics Data System (ADS)

    Hiraiwa, M.; Abe, M.; Hashimoto, S.

    2014-12-01

    Phytoplankton are known to produce volatile organic compounds (VOCs), which contribute to environmental problems such as global warming and decomposition of stratospheric ozone. For example, picophytoplankton, such as Prochlorococcus and Synechococcus, are distributed in freshwater and oceans worldwide, accounting for a large proportion of biomass and primary production in the open ocean. However, to date, little is known about the production of VOCs by picophytoplankton. In this study, VOCs production by cyanobacteria Synechococcus sp. (NIES-981) was investigated. Synechococcus sp. was obtained from the National Institute for Environmental Studies (NIES), Japan, and cultured at 24°C in autoclaved f/2-Si medium under 54 ± 3 µE m-2 s-1 (1 E = 1 mol of photons) with a 12-h light and 12-h dark cycle. VOCs concentrations were determined using a purge-and-trap gas chromatograph-mass spectrometer (Agilent 5973). The concentrations of chlorophyll a (Chl a) were also determined using a fluorometer (Turner TD-700). Bromomethane (CH3Br) and isoprene were produced by Synechococcus sp. Isoprene production was similar to those of other phytoplankton species reported earlier. Isoprene was produced when Chl a was increasing in the early stage of the incubation period (5-15 days of incubation time, exponential phase), but CH3Br was produced when Chl a was reduced in the late stage of the incubation period (30-40 days of incubation time, death phase).

  1. Cost effective passive sampling device for volatile organic compounds monitoring

    NASA Astrophysics Data System (ADS)

    Thammakhet, Chongdee; Muneesawang, Vilailuk; Thavarungkul, Panote; Kanatharana, Proespichaya

    A laboratory-built passive sampler was developed as a simple and cost effective device for monitoring volatile organic compounds (VOCs) such as benzene, toluene and xylene (BTX). Common glass bottles (screw cap, 10 ml, 67.6×10.6 mm ID), packed with 75 mg of activated Tenax TA, were used as passive samplers. After exposed to real sample, the adsorbent was desorbed using a laboratory-built thermal desorption device. The analytes were purged to fill a sampling loop and then injected by a gas sampling valve to a gas chromatograph with a flame ionization detector (FID). All parameters, i.e. , desorption time, purge flow rate, gas chromatograph conditions were optimized to obtain high sensitivity, resolution and short analysis time. The system was calibrated by BTX standard gas and the linear regression coefficient of greater than 0.99 was obtained with detection limits 0.3, 0.2 and 0.7 μg m -3 for benzene, toluene and xylene, respectively. The proposed method was implemented for the monitoring of BTX at 10 gasoline stations in Hat Yai, Thailand. The concentrations were found in the range of N.D.-19, 12-200 and 23-200 μg m -3 for benzene, toluene and xylene, respectively.

  2. Remediation of ground water containing volatile organic compounds and tritium

    SciTech Connect

    Shukla, S.N.; Folsom, E.N.

    1994-03-01

    The Trailer 5475 (T-5475) East Taxi Strip Area at Lawrence Livermore National Laboratory (LLNL), Livermore, California was used as a taxi strip by the US Navy to taxi airplanes to the runway from 1942 to 1947. Solvents were used in some unpaved areas adjacent to the East Taxi Strip for cleaning airplanes. From 1953 through 1976, the area was used to store and treat liquid waste. From 1962 to 1976 ponds were constructed and used for evaporation of liquid waste. As a result, the ground water in this area contains volatile organic compounds (VOCs) and tritium. The ground water in this area is also known to contain hexavalent chromium that is probably naturally occurring. Therefore, LLNL has proposed ``pump-and-treat`` technology above grade in a completely closed loop system. The facility will be designed to remove the VOCs and hexavalent chromium, if any, from the ground water, and the treated ground water containing tritium will be reinjected where it will decay naturally in the subsurface. Ground water containing tritium will be reinjected into areas with equal or higher tritium concentrations to comply with California regulations.

  3. Volatile Organic Compounds: Characteristics, distribution and sources in urban schools

    NASA Astrophysics Data System (ADS)

    Mishra, Nitika; Bartsch, Jennifer; Ayoko, Godwin A.; Salthammer, Tunga; Morawska, Lidia

    2015-04-01

    Long term exposure to organic pollutants, both inside and outside school buildings may affect children's health and influence their learning performance. Since children spend significant amount of time in school, air quality, especially in classrooms plays a key role in determining the health risks associated with exposure at schools. Within this context, the present study investigated the ambient concentrations of Volatile Organic Compounds (VOCs) in 25 primary schools in Brisbane with the aim to quantify the indoor and outdoor VOCs concentrations, identify VOCs sources and their contribution, and based on these; propose mitigation measures to reduce VOCs exposure in schools. One of the most important findings is the occurrence of indoor sources, indicated by the I/O ratio >1 in 19 schools. Principal Component Analysis with Varimax rotation was used to identify common sources of VOCs and source contribution was calculated using an Absolute Principal Component Scores technique. The result showed that outdoor 47% of VOCs were contributed by petrol vehicle exhaust but the overall cleaning products had the highest contribution of 41% indoors followed by air fresheners and art and craft activities. These findings point to the need for a range of basic precautions during the selection, use and storage of cleaning products and materials to reduce the risk from these sources.

  4. Characterization of volatile organic compounds from different cooking emissions

    NASA Astrophysics Data System (ADS)

    Cheng, Shuiyuan; Wang, Gang; Lang, Jianlei; Wen, Wei; Wang, Xiaoqi; Yao, Sen

    2016-11-01

    Cooking fume is regarded as one of the main sources of urban atmospheric volatile organic compounds (VOCs) and its chemical characteristics would be different among various cooking styles. In this study, VOCs emitted from four different Chinese cooking styles were collected. VOCs concentrations and emission characteristics were analyzed. The results demonstrated that Barbecue gave the highest VOCs concentrations (3494 ± 1042 μg/m3), followed by Hunan cuisine (494.3 ± 288.8 μg/m3), Home cooking (487.2 ± 139.5 μg/m3), and Shandong cuisine (257.5 ± 98.0 μg/m3). The volume of air drawn through the collection hood over the stove would have a large impact on VOCs concentration in the exhaust. Therefore, VOCs emission rates (ER) and emission factors (EF) were also estimated. Home cooking had the highest ER levels (12.2 kg/a) and Barbecue had the highest EF levels (0.041 g/kg). The abundance of alkanes was higher in Home cooking, Shandong cuisine and Hunan cuisine with the value of 59.4%-63.8%, while Barbecue was mainly composed of alkanes (34.7%) and alkenes (39.9%). The sensitivity species of Home cooking and Hunan cuisine were alkanes, and that of Shandong cuisine and Barbecue were alkenes. The degree of stench pollution from cooking fume was lighter.

  5. Volatile organic compound monitoring by photo acoustic radiometry

    SciTech Connect

    Sollid, J.E.; Trujillo, V.L.; Limback, S.P.; Woloshun, K.A.

    1995-12-01

    Two methods for sampling and analyzing volatile organics in subsurface pore gas were developed for use at the Hazardous Waste Disposal Site at Los Alamos National Laboratory. One is Thermal Desorption Gas Chromatography Mass Spectrometry (TDGCMS), the other is Photoacoustic Radiometry (PAR). Presented here are two years worth of experience and lessons learned as both techniques matured. The sampling technique is equally as important as the analysis method. PAR is a nondispersive infrared technique utilizing band pass filters in the region from 1 to 15 {mu}m. A commercial instrument, the Model 1302 Multigas Analyzer, made by Bruel and Kjaer, was adapted for field use. To use the PAR there must be some a priori knowledge of the constellation of analytes to be measured. The TDGCMS method is sensitive to 50 analytes. Hence TDGCMS is used in an initial survey of the site to determine what compounds are present and at what concentration. Once the major constituents of the soil-gas vapor plume are known the PAR can be configured to monitor for the five analytes of most interest. The PAR can analyse a sample in minutes, while in the field. The PAR is also quite precise in controlled situations.

  6. Removal of volatile organic compounds (VOCs) using biofilters

    SciTech Connect

    Carriere, P.E.; Mohaghegh, S.D.; Madabhushi, B.S.

    1995-12-31

    One of the most significant air pollution control challenges being faced by the Federal and State agencies and the chemical process industries is the control of emissions of volatile organic compounds (VOCs). VOCs are discharged from process industries as major components of mixed organic wastes which contaminate the environment. Among these wastes, benzene, toluene, ethyl benzene and xylene are classified as major pollutants with high frequencies of occurrence on the EPA list of priority pollutants. Biofiltration, a recent air pollution control technology, is the removal and decomposition of contaminants present in emissions of non hazardous substances using a biologically activated medium. Biofiltration involves contacting the contaminated emission gas stream with microorganisms in a filter media. Biofiltration utilizes microorganisms immobilized in the form of a biofilm layer on an adsorptive filter media. Compared to other technologies, biofiltration is inexpensive, reliable and requires no post treatment. The main objective of this study was to compare the performance of both Granular Activated Carbon (GAC) and Biologically Activated Carbon (BAC) for the removal of benzene and toluene.

  7. Volatile organic compounds exposure and cardiovascular effects in hair salons.

    PubMed

    Ma, C-M; Lin, L-Y; Chen, H-W; Huang, L-C; Li, J-F; Chuang, K-J

    2010-12-01

    The relationship between occupational exposures to volatile organic compounds (VOCs) and cardiovascular effects among hairdressing assistants has not been well characterized. To investigate whether or not exposure to VOCs was associated with autonomic dysfunction, inflammation and oxidative stress in hairdressing assistants. We recruited 62 young healthy assistants working in different hair salons in Taipei. Blood samples were taken from each assistant and heart rate variability (HRV) indices were recorded. VOCs were measured at each assistant's workplace. Mixed-effects models were used to examine the association between blood markers, HRV and VOCs. Exposure to VOCs was associated with increases in serum C-reactive protein (CRP) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) as well as decreases in HRV indices. The effect of VOCs exposure on the health parameters measured in this study was greatest during the days on which the subjects were working. Occupational exposure to VOCs in hair salons can lead to increases in serum CRP and 8-OHdG levels and decreases in HRV indices. Time spent away from the workplace could modify the effects these exposures have on the health parameters described above in these assistants.

  8. Volatile organic compounds in the atmosphere of Mexico City

    NASA Astrophysics Data System (ADS)

    Garzón, Jessica P.; Huertas, José I.; Magaña, Miguel; Huertas, María E.; Cárdenas, Beatriz; Watanabe, Takuro; Maeda, Tsuneaki; Wakamatsu, Shinji; Blanco, Salvador

    2015-10-01

    The Mexico City Metropolitan Area (MCMA) is one of the most polluted megacities in North America. Therefore, it is an excellent benchmark city to understand atmospheric chemistry and to implement pilot countermeasures. Air quality in the MCMA is not within acceptable levels, mainly due to high ground levels of ozone (O3). Tropospheric O3 is a secondary pollutant formed from the oxidation of volatile organic compounds (VOCs) in the presence of nitrogen oxides and sunlight. To gain a better understanding of O3 formation in megacities, evaluate the effectiveness of already-implemented countermeasures, and identify new cost-effective alternatives to reduce tropospheric O3 concentrations, researchers and environmental authorities require updated concentrations for a broader range of VOCs. Moreover, in an effort to protect human health and the environment, it is important to understand which VOCs exceed reference safe values or most contribute to O3 formation, as well as to identify the most probable emission sources of those VOCs. In this work, 64 VOCs, including 36 toxic VOCs, were measured at four sites in the MCMA during 2011-2012. VOCs related to liquefied petroleum gas leakages exhibited the highest concentrations. Toxic VOCs with the highest average concentrations were acetone and ethanol. The toxic VOC benzene represented the highest risk to Mexican citizens, and toluene contributed the most to O3 formation. Correlation analysis indicated that the measured VOCs come from vehicular emissions and solvent-related industrial sources.

  9. Advanced heat pump for the recovery of volatile organic compounds

    NASA Astrophysics Data System (ADS)

    1992-03-01

    Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total U.S. VOC emissions. The 'Toxic-Release Inventory' of the U.S. Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing, refrigerant production, and wood products production. The U.S. Department of Energy's (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase 1 report documents 3M's work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. The Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient, and economically priced.

  10. A novel nanostructure for ultrasensitive volatile organic compound sensing

    NASA Astrophysics Data System (ADS)

    Zhao, Huaizhou; Rizal, Binod; Ren, Zhifeng; Naughton, Michael J.; Chiles, Thomas C.; Cai, Dong

    2011-03-01

    We have developed an arrayed nanocoaxial structure for the ultrasensitive sensing detection and identification of volatile organic compounds (VOC) by dielectric impedance spectroscopy. VOC molecules are absorbed into porous dielectric material in the annulus between nanoscale coax electrodes. A theoretical expression for the basic adsorption mechanism agrees with the experimental results. Detection sensitivities at parts-per-billion levels were demonstrated for a variety of VOCs. A limit-of-detection of ethanol reached ~ 100 parts-per-trillion, following a Freundlich power-law isotherm across four decades of ethanol concentration. A linear dependence on VOC dielectric constant was observed. Dielectric impedance nanospectroscopy was also performed by scanning frequency from 10 mHz to 1 MHz, with distinctive spectra of different VOCs discovered. These were utilized to conduct colorimetric identification of VOCs. The results suggest our novel nanocoaxial sensor can be used as a sensitive, broadband, and multimodal sensing platform for chemical detection. The National Cancer Institute CA137681, the Department of Navy, the National Science Foundation PHY-0804718, and the Seaver Institute. Emails: caid@bc.edu; naughton@bc.edu.

  11. Evaluation of Volatile Organic Compound Emissions from Megacities and Wildfires

    NASA Astrophysics Data System (ADS)

    Emmons, L. K.; Apel, E. C.; Hornbrook, R. S.; Riemer, D. D.; Lamarque, J.; Wiedinmyer, C.; Mirage Science Team; Arctas Science Team

    2011-12-01

    Volatile organic compounds (VOCs) play a critical role in determining air quality through their impact on ozone production and other pollutants. Tropospheric chemistry models use a variety of treatments for the lumping of VOCs in their chemical mechanisms, as a compromise between detailed treatment and computational speed. However, emission inventories are frequently provided for only total VOCs with little or no information on how to split the emissions among the model species, introducing additional uncertainty to the model simulations. Global model simulations using the Model for Ozone and Related Chemical Tracers (MOZART-4) and several different emission inventories are evaluated through detailed comparison to aircraft and surface observations. In particular, correlations between measured VOCs and CO are used to test the emission inventory emission ratios of the modeled VOC species. For example, megacity VOC emissions will be evaluated with surface measurements in Mumbai, Shanghai and Tokyo, as well as aircraft measurements from the NSF/MIRAGE experiment downwind of Mexico City. Wildfire emissions in Siberia, Canada and California will be evaluated using airborne observations of the NASA/ARCTAS experiment.

  12. Development and mining of a volatile organic compound database.

    PubMed

    Abdullah, Azian Azamimi; Altaf-Ul-Amin, Md; Ono, Naoaki; Sato, Tetsuo; Sugiura, Tadao; Morita, Aki Hirai; Katsuragi, Tetsuo; Muto, Ai; Nishioka, Takaaki; Kanaya, Shigehiko

    2015-01-01

    Volatile organic compounds (VOCs) are small molecules that exhibit high vapor pressure under ambient conditions and have low boiling points. Although VOCs contribute only a small proportion of the total metabolites produced by living organisms, they play an important role in chemical ecology specifically in the biological interactions between organisms and ecosystems. VOCs are also important in the health care field as they are presently used as a biomarker to detect various human diseases. Information on VOCs is scattered in the literature until now; however, there is still no available database describing VOCs and their biological activities. To attain this purpose, we have developed KNApSAcK Metabolite Ecology Database, which contains the information on the relationships between VOCs and their emitting organisms. The KNApSAcK Metabolite Ecology is also linked with the KNApSAcK Core and KNApSAcK Metabolite Activity Database to provide further information on the metabolites and their biological activities. The VOC database can be accessed online.

  13. Pollution due to volatile halocarbon compounds in biota

    SciTech Connect

    Gotoh, Masayuki ); Sekitani, Yoshiko; Aramaki, Teruyo; Kobayashi, Haruo; Ogino, Keiki; Hobara, Tatsuya )

    1992-08-01

    In recent years, volatile halocarbon compounds (VHCs) in drinking water have elicited increasing social concern and health problems. Further, it was reported that carcinogenic and/or mutagenic effects have been induced in animals by several VHCs. These substances were also detected in biota, sediment, and human food. Several methods were developed for the determination of VHCs in these types of samples. In each case, VHCs were eventually measured by gas chromatography. One of the pretreatment techniques involves the fairly simple procedure where samples are extracted with isooctane and subsequently isolated by micro florisil column. However, this method is susceptible to low recovery. Ferrario et al. (1985) reported that ecosystems in Lake Pontchartrain were polluted based on the fact that VHCs were detected by the purge and trap method, using a pretreatment method slightly different from the ones mentioned above. Nevertheless, no report about an evaluation of the amount of pollutants in biota as human food was found. In this report, the substantially improved Daft method for VHC analysis was applied to environmental biota and sediments, and an attempt was made to clarify the cause of pollution due to VHCs in biota. Furthermore, we found several interesting phenomena concerning the movement of VHCs in biota. 8 refs., 1 fig., 3 tabs.

  14. Development and Mining of a Volatile Organic Compound Database

    PubMed Central

    Abdullah, Azian Azamimi; Altaf-Ul-Amin, Md.; Ono, Naoaki; Sato, Tetsuo; Sugiura, Tadao; Morita, Aki Hirai; Katsuragi, Tetsuo; Muto, Ai; Nishioka, Takaaki; Kanaya, Shigehiko

    2015-01-01

    Volatile organic compounds (VOCs) are small molecules that exhibit high vapor pressure under ambient conditions and have low boiling points. Although VOCs contribute only a small proportion of the total metabolites produced by living organisms, they play an important role in chemical ecology specifically in the biological interactions between organisms and ecosystems. VOCs are also important in the health care field as they are presently used as a biomarker to detect various human diseases. Information on VOCs is scattered in the literature until now; however, there is still no available database describing VOCs and their biological activities. To attain this purpose, we have developed KNApSAcK Metabolite Ecology Database, which contains the information on the relationships between VOCs and their emitting organisms. The KNApSAcK Metabolite Ecology is also linked with the KNApSAcK Core and KNApSAcK Metabolite Activity Database to provide further information on the metabolites and their biological activities. The VOC database can be accessed online. PMID:26495281

  15. Mass spectrometry analysis of volatile compounds in raw meat for the authentication of the feeding background of farm animals.

    PubMed

    Vasta, Valentina; Ratel, Jeremy; Engel, Erwan

    2007-06-13

    The authentication of the conditions of animal production, based on the analysis of meat commercial cuts, is a major challenge on both societal and analytical grounds. The aim of the present work was to propose a method for the extraction of the volatile compounds from ruminant raw muscles trimmed of fat and to assess by mass spectrometry-based techniques the relevance of these compounds for the authentication of the type of feeding offered to the animals. The first step of the study consisted of validating conditions of dynamic headspace (DH) extraction of volatile compounds that enabled us to minimize the appearance of heat-induced artifacts and to maximize the richness of the DH-gas chromatography-mass spectrometry profile (DH-GC-MS) of raw lamb muscle. An extraction temperature of 35 degrees C (vs 60 and 90 degrees C) and a sample mass of 6.25 g (vs 12.5, 25, and 50 g) were shown to be suitable. The second step aimed at identifying volatile compounds enabling us to discriminate muscle samples from 16 experimental lambs fed either concentrate (n = 8) or pasture (n = 8). Before, to carefully explore the information given by the DH-GC-MS signal, the MS spectra acquired along the chromatogram were summed and then converted in a virtual-DH-MS spectral fingerprint to have a quick overview of the discriminative potential of the volatile fraction. According to univariate (analysis of variance) and to multivariate (principal component analysis) data treatments performed on virtual-DH-MS fingerprints, the meat volatile fraction was relevant to reveal the type of feeding of the living animal. The detailed examination of the information given by the GC dimension showed that 33 volatile compounds among the 204 detected in the muscle by DH-GC-MS enabled us to discriminate the type of feeding of the lambs. The relevance of these results is discussed in light of previous studies performed on adipose tissues.

  16. Evolution of volatile compounds and biogenic amines throughout the shelf life of marinated and salted anchovies (Engraulis encrasicolus).

    PubMed

    Dehaut, Alexandre; Himber, Charlotte; Mulak, Véronique; Grard, Thierry; Krzewinski, Frédéric; Le Fur, Bruno; Duflos, Guillaume

    2014-08-13

    Producers of processed anchovies have developed hazard analysis and critical control points (HACCP) to guarantee the quality of their products. Nonetheless there is a lack of objective data to determine products' shelf life. The quality of a product is usually established on the basis of its safety and organoleptic properties. These parameters were assessed by monitoring the profiles of volatile compounds and quantitating six biogenic amines in samples of two types of processed anchovies during their shelf life. With regard to biogenic amines, quantities were below the regulatory limits throughout shelf life, except when a temperature abuse was applied for marinated samples. Moreover, this work highlights an optimum volatile profile at 5 and 6 months of storage for salted and marinated anchovies, respectively. This is the result of a higher content of six aldehyde and nine ketone compounds, mainly from lipid oxidation.

  17. Microcantilever sensors coated with a sensitive polyaniline layer for detecting volatile organic compounds.

    PubMed

    Steffens, C; Leite, F L; Manzoli, A; Sandovall, R D; Fatibello, O; Herrmann, P S P

    2014-09-01

    This paper describes a silicon cantilever sensor coated with a conducting polymer layer. The mechanical response (deflection) of the bimaterial (the coated microcantilever) was investigated under the influence of several volatile compounds-methanol, ethanol, acetone, propanol, dichloroethane, toluene and benzene. The variations in the deflection of the coated and uncoated microcantilevers when exposed to volatile organic compounds were evaluated, and the results indicated that the highest sensitivity was obtained with the coated microcantilever and methanol. The uncoated microcantilever was not sensitive to the volatile organic compounds. An increase in the concentration of the volatile organic compound resulted in higher deflections of the microcantilever sensor. The sensor responses were reversible, sensible, rapid and proportional to the volatile concentration.

  18. Does the volatile hydrocarbon profile differ between the sexes: a case study on five aphidophagous ladybirds.

    PubMed

    Pattanayak, Rojalin; Mishra, Geetanjali; Omkar; Chanotiya, Chandan Singh; Rout, Prasant Kumar; Mohanty, Chandra Sekhar

    2014-11-01

    Insect hydrocarbons (HCs) primarily serve as a waterproofing cuticular layer and function extensively in chemical communication by facilitating species, sex, and colony recognition. In this study, headspace solid-phase microextraction is employed for investigating the sex-specific volatile HC profile of five ladybirds collected from Lucknow, India namely, Coccinella septempunctata (L.), Coccinella transversalis (Fabr.), Menochilus sexmaculatus (Fabr.), Propylea dissecta (Mulsant), and Anegleis cardoni (Weise) for the first time. Major compounds reported in C. septempunctata, C. transversalis, and A. cardoni are methyl-branched saturated HCs, whereas in M. sexmaculatus, and P. dissecta, they are unsaturated HCs. Other than A. cardoni, both the sexes of the other four ladybirds had similar compounds at highest peak but with statistically significant differences. However, in A. cardoni, which is a beetle with a narrow niche, the major compound in both male and female was different. The difference in volatile HC profile of the sexes of the five ladybirds indicates that gender-specific differences primarily exist due to quantitative differences in chemicals with only very few chemicals being unique to a gender. This variation in semiochemicals might have a role in behavioral or ecological aspects of the studied ladybirds. © 2014 Wiley Periodicals, Inc.

  19. 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.

  20. Source apportionment of volatile organic compounds measured in Edmonton, Alberta

    NASA Astrophysics Data System (ADS)

    McCarthy, Michael C.; Aklilu, Yayne-Abeba; Brown, Steven G.; Lyder, David A.

    2013-12-01

    From 2003 to 2009, whole air samples were collected at two sites in Edmonton and analyzed for over 77 volatile organic compounds (VOCs). VOCs were sampled in the downtown area (Central site) and an industrial area on the eastern side of the city (East site). Concentrations of most VOCs were highest at the East site, with an average total VOC mass concentration of 221 μg m-3. The average total VOC mass concentration at the Central site was 65 μg m-3. The United States Environmental Protection Agency's positive matrix factorization receptor model (EPA PMF) was used to apportion ambient concentrations of VOCs into eleven factors, which were associated with emissions sources. On average, 94 and 99% of the measured mass were apportioned by PMF at the East and Central site, respectively. Factors include transportation combustion (gasoline and diesel), industrial sources (industrial evaporative, industrial feedstock, gasoline production/storage, industrial chemical use), mixed mobile and industrial (gasoline evaporative, fugitive butane), a biogenic source, a natural gas related source, and a factor that was associated with global background pollutants transported into the area. Transportation sources accounted for more than half of the reconstructed VOC mass concentration at the Central site, but less than 10% of the reconstructed mass concentration at the East site. By contrast, industrial sources accounted for ten times more of the reconstructed VOC mass concentration at the East site than at the Central site and were responsible for approximately 75% of the reconstructed VOC mass concentration observed at the East site. Of the six industrial factors identified at the East site, four were linked to petrochemical industry production and storage. The two largest contributors to the reconstructed VOC mass concentration at the East site were associated with fugitive emissions of volatile species (butanes, pentanes, hexane, and cyclohexane); together, these two factors