Science.gov

Sample records for abundant volatile compound

  1. Abundances and variability of tropospheric volatile organic compounds at the South Pole and other Antarctic locations

    NASA Astrophysics Data System (ADS)

    Beyersdorf, Andreas J.; Blake, Donald R.; Swanson, Aaron; Meinardi, Simone; Rowland, F. S.; Davis, Douglas

    2010-11-01

    Multiyear (2000-2006) seasonal measurements of carbon monoxide, hydrocarbons, halogenated species, dimethyl sulfide, carbonyl sulfide and C 1-C 4 alkyl nitrates at the South Pole are presented for the first time. At the South Pole, short-lived species (such as the alkenes) typically were not observed above their limits of detection because of long transit times from source regions. Peak mixing ratios of the longer lived species with anthropogenic sources were measured in late winter (August and September) with decreasing mixing ratios throughout the spring. In comparison, compounds with a strong oceanic source, such as bromoform and methyl iodide, had peak mixing ratios earlier in the winter (June and July) because of decreased oceanic production during the winter months. Dimethyl sulfide (DMS), which is also oceanically emitted but has a short lifetime, was rarely measured above 5 pptv. This is in contrast to high DMS mixing ratios at coastal locations and shows the importance of photochemical removal during transport to the pole. Alkyl nitrate mixing ratios peaked during April and then decreased throughout the winter. The dominant source of the alkyl nitrates in the region is believed to be oceanic emissions rather than photochemical production due to low alkane levels. Sampling of other tropospheric environments via a Twin Otter aircraft included the west coast of the Ross Sea and large stretches of the Antarctic Plateau. In the coastal atmosphere, a vertical gradient was found with the highest mixing ratios of marine emitted compounds at low altitudes. Conversely, for anthropogenically produced species the highest mixing ratios were measured at the highest altitudes, suggesting long-range transport to the continent. Flights flown through the plume of Mount Erebus, an active volcano, revealed that both carbon monoxide and carbonyl sulfide are emitted with an OCS/CO molar ratio of 3.3 × 10 -3 consistent with direct observations by other investigators within the

  2. Volatile Organic Compounds in Uremia

    PubMed Central

    Seifert, Luzia; Slodzinski, Rafael; Jankowski, Joachim; Zidek, Walter; Westhoff, Timm H.

    2012-01-01

    Background Although “uremic fetor” has long been felt to be diagnostic of renal failure, the compounds exhaled in uremia remain largely unknown so far. The present work investigates whether breath analysis by ion mobility spectrometry can be used for the identification of volatile organic compounds retained in uremia. Methods Breath analysis was performed in 28 adults with an eGFR ≥60 ml/min per 1.73 m2, 26 adults with chronic renal failure corresponding to an eGFR of 10–59 ml/min per 1.73 m2, and 28 adults with end-stage renal disease (ESRD) before and after a hemodialysis session. Breath analysis was performed by ion mobility spectrometryafter gas-chromatographic preseparation. Identification of the compounds of interest was performed by thermal desorption gas chromatography/mass spectrometry. Results Breath analyses revealed significant differences in the spectra of patients with and without renal failure. Thirteen compounds were chosen for further evaluation. Some compounds including hydroxyacetone, 3-hydroxy-2-butanone and ammonia accumulated with decreasing renal function and were eliminated by dialysis. The concentrations of these compounds allowed a significant differentiation between healthy, chronic renal failure with an eGFR of 10–59 ml/min, and ESRD (p<0.05 each). Other compounds including 4-heptanal, 4-heptanone, and 2-heptanone preferentially or exclusively occurred in patients undergoing hemodialysis. Conclusion Impairment of renal function induces a characteristic fingerprint of volatile compounds in the breath. The technique of ion mobility spectrometry can be used for the identification of lipophilic uremic retention molecules. PMID:23049998

  3. Volatile organic compound sensor system

    DOEpatents

    Schabron, John F.; Rovani, Jr., Joseph F.; Bomstad, Theresa M.; Sorini-Wong, Susan S.; Wong, Gregory K.

    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.

  4. Volatile organic compound sensor system

    DOEpatents

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

    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.

  5. Biofiltration of volatile organic compounds.

    PubMed

    Malhautier, Luc; Khammar, Nadia; Bayle, Sandrine; Fanlo, Jean-Louis

    2005-07-01

    The removal of volatile organic compounds (VOCs) from contaminated airstreams has become a major air pollution concern. Improvement of the biofiltration process commonly used for the removal of odorous compounds has led to a better control of key parameters, enabling the application of biofiltration to be extended also to the removal of VOCs. Moreover, biofiltration, which is based on the ability of micro-organisms to degrade a large variety of compounds, proves to be economical and environmentally viable. In a biofilter, the waste gas is forced to rise through a layer of packed porous material. Thus, pollutants contained in the gaseous effluent are oxidised or converted into biomass by the action of microorganisms previously fixed on the packing material. The biofiltration process is then based on two principal phenomena: (1) transfer of contaminants from the air to the water phase or support medium, (2) bioconversion of pollutants to biomass, metabolic end-products, or carbon dioxide and water. The diversity of biofiltration mechanisms and their interaction with the microflora mean that the biofilter is defined as a complex and structured ecosystem. As a result, in addition to operating conditions, research into the microbial ecology of biofilters is required in order better to optimise the management of such biological treatment systems. PMID:15803311

  6. 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.

  7. 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.

  8. Analyzing volatile compounds in dairy products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. 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.

  10. 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...

  11. 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. PMID:17926127

  12. Lunar apatite with terrestrial volatile abundances.

    PubMed

    Boyce, Jeremy W; Liu, Yang; Rossman, George R; Guan, Yunbin; Eiler, John M; Stolper, Edward M; Taylor, Lawrence A

    2010-07-22

    The Moon is thought to be depleted relative to the Earth in volatile elements such as H, Cl and the alkalis. Nevertheless, evidence for lunar explosive volcanism has been used to infer that some lunar magmas exsolved a CO-rich and CO(2)-rich vapour phase before or during eruption. Although there is also evidence for other volatile species on glass spherules, until recently there had been no unambiguous reports of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite from lunar basalt 14053 that document concentrations of H, Cl and S that are indistinguishable from apatites in common terrestrial igneous rocks. These volatile contents could reflect post-magmatic metamorphic volatile addition or growth from a late-stage, interstitial, sulphide-saturated melt that contained approximately 1,600 parts per million H(2)O and approximately 3,500 parts per million Cl. Both metamorphic and igneous models of apatite formation suggest a volatile inventory for at least some lunar materials that is similar to comparable terrestrial materials. One possible implication is that portions of the lunar mantle or crust are more volatile-rich than previously thought. PMID:20651686

  13. Volatile organic compound emissions from silage systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. 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...

  15. 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

  16. 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.

  17. 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.

  18. 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. PMID:25952837

  19. 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. PMID:23472454

  20. The Negative Effects of Volatile Sulphur Compounds.

    PubMed

    Milella, Lisa

    2015-01-01

    Oral malodor has been studied extensively in humans but not necessarily to the same degree in our veterinary patients where malodor constitutes a significant problem. Breath malodor may originate from the mouth, or from an extra oral source, originating from other organ systems such as gastrointestinal, respiratory, or even systemic disease. Oral malodor is a result of microbial metabolism of exogenous and endogenous proteinaceous substrates leading to the production of compounds such as indole, skatole, tyramine, cadaverine, puterescine, mercaptans, and sulphides. Volatile sulphur compounds have been shown to be the main cause of oral malodor. Although most clients perceive oral malodor to be primarily a cosmetic problem, there is an increasing volume of evidence in human dental literature demonstrating that volatile sulphur compounds produced by bacteria, even at low concentrations, are toxic to tissues and play a role in the pathogenesis of periodontitis. This article reviews the current available literature in human dentistry looking at these negative effects. No veterinary studies have been conducted looking at the negative effects of volatile sulphur compounds specifically, but as this article highlights, we should be aware of the potential negative effects of volatile sulphur compounds and consider this an area of future research. PMID:26415386

  1. TREATMENT OF VOLATILE ORGANIC COMPOUNDS IN DRINKING WATER

    EPA Science Inventory

    Volatile chlorinated and non-chlorinated compounds occur in both untreated and treated drinking water. Because volatilization is restricted, ground waters rather than surface waters are more likely to have high concentrations of these compounds. This document reviews properties, ...

  2. Mars and earth - Origin and abundance of volatiles

    NASA Technical Reports Server (NTRS)

    Anders, E.; Owen, T.

    1977-01-01

    An investigation is conducted concerning the factors which are responsible for the tenuous nature of the Martian atmosphere in comparison to the terrestrial atmosphere, taking into account new data obtained in connection with the Viking missions. It is found that Mars was poor in volatiles from the start and fell further behind earth by less complete outgassing, by extensive retrapping, and by the partial loss of lighter gases. Attention is given to noble gases on earth and Mars, the condensation of noble gases and other volatiles, the sources of earth's volatiles, the bulk composition of earth, the release of volatiles from earth, clues to the volatile endowment of Mars, an abundance table for Mars, a comparison of terrestrial and Martian conditions, isotopic data on noble gases, xenon-129 on Mars and earth, possibilities concerning the loss of an early Martian atmosphere, the evolution of the atmosphere of Mars, conditions in the case of planet Venus, and the reasons for the poorness of small planets in volatiles.

  3. Endogenous Lunar Volatiles: Insights into the Abundances of Volatiles in the Moon from Lunar Apatite

    NASA Technical Reports Server (NTRS)

    McCubbin, Francis

    2016-01-01

    At the time of publication of New Views of the Moon, it was thought that the Moon was bone dry with less than about 1 ppb H2O. However in 2007, initial reports at the 38th Lunar and Planetary Science Conference speculated that H-species were present in both apatites and pyroclastic volcanic lunar glasses. These early reports were later confirmed through peer-review, which motivated many subsequent studies on magmatic volatiles in and on the Moon within the last decade. Some of these studies have cast into question the post-Apollo view of lunar formation, the distribution and sources of volatiles in the Earth-Moon system, and the thermal and magmatic evolution of the Moon. The mineral apatite has been one of the pillars of this new field of study, and it will be the primary focus of this abstract. Although apatite has been used both to understand the abundances of volatiles in lunar systems as well as the isotopic compositions of those volatiles, the focus here will be on the abundances of F, Cl, and H2O. This work demonstrates the utility of apatite in advancing our understanding of lunar volatiles, hence apatite should be among the topics covered in the endogenous lunar volatile chapter in NVM II. Truncated ternary plot of apatite X-site occupancy (mol%) from highlands apatite and mare basalt apatite plotted on the relative volatile abundance diagram from. The solid black lines delineate fields of relative abundances of F, Cl, and H2O (on a weight basis) in the melt from which the apatite crystallized. The diagram was constructed using available apatite/melt partitioning data for fluorine, chlorine, and hydroxyl.

  4. 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. PMID:27283624

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Volatile compounds of Van Herby cheeses produced with raw and pasteurized milks from different species.

    PubMed

    Ocak, Elvan; Javidipour, Issa; Tuncturk, Yusuf

    2015-07-01

    Levels of volatile compounds in Van herby cheeses manufactured from raw and pasteurized; 100 % ewes', 50 % ewes'+50 % cows' and mixture of 50 % ewes'+25 % cows'+25 % goats' milks were investigated over 180 days of ripening at 4 °C. The volatile compounds levels of herby cheese samples increased throughout the 180 days storage period. Samples produced from pasteurized milk showed lower volatile contents than their counterparts produced from raw milk. The volatile compounds profile of herby cheese samples detected by headspace solid-phase microextraction (HS-SPME) consisted of 8 esters, 5 ketones, 5 aldehydes, 9 acids, 6 alcohols and 14 hydrocarbons and terpenes. Acetic acid was the most abundant volatile compound in HS-SPME of ripened cheeses, followed by hexanoic, octanoic and butanoic acids. PMID:26139896

  7. 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.

  8. Performance of commercial non-methane hydrocarbon analyzers in monitoring polar volatile organic compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying non-methane hydrocarbons (NMHC) from animal feeding operations (AFOs) is challenging due to the broad spectrum of compounds and the polar nature of the most abundant compounds. The purpose of this study was to determine the performance of commercial NMHC analyzers for measuring volatile ...

  9. 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. PMID:25870012

  10. 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.

  11. 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.

  12. Alkaline dechlorination of chlorinated volatile organic compounds

    SciTech Connect

    Gu, B.; Siegrist, R.L.

    1996-06-01

    The vast majority of contaminated sites in the United States and abroad are contaminated with chlorinated volatile organic compounds (VOCs) such as trichloroethylene (TCE), trichloroethane (TCA), and chloroform. These VOCs are mobile and persistent in the subsurface and present serious health risks at trace concentrations. The goal of this project was to develop a new chemical treatment system that can rapidly and effectively degrade chlorinated VOCs. The system is based on our preliminary findings that strong alkalis such as sodium hydroxide (NaOH) can absorb and degrade TCE. The main objectives of this study were to determine the reaction rates between chlorinated VOCs, particularly TCE, and strong alkalis, to elucidate the reaction mechanisms and by-products, to optimize the chemical reactions under various experimental conditions, and to develop a laboratory bench- scale alkaline destruction column that can be used to destroy vapor- phase TCE.

  13. Mars and Earth: origin and abundance of volatiles.

    PubMed

    Anders, E; Owen, T

    1977-11-01

    Mars, like Earth, may have received its volatiles in the final stages of accretion, as a veneer of volatile-rich material similar to C3V carbonaceous chondrites. The high (40)Ar/(36)Ar ratio and low (36)Ar abundance on Mars, compared to data for other differentiated planets, suggest that Mars is depleted in volatiles relative to Earth-by a factor of 1.7 for K and 14 other moderately volatile elements and by a factor of 35 for (36)Ar and 15 other highly volatile elements. Using these two scaling factors, we have predicted martian abundances of 31 elements from terrestrial abundances. Comparison with the observed (36)Ar abundance suggests that outgassing on Mars has been about four times less complete than on Earth. Various predictions of the model can be checked against observation. The initial abundance of N, prior to escape, was about ten times the present value of 0.62 ppb, in good agreement with an independent estimate based on the observed enhancement in the martian (15)N/(14)N ratio (78,79). The initial water content corresponds to a 9-m layer, close to the value of >/=13 m inferred from the lack of an (18)O/(16)O fractionation (75). The predicted crustal Cl/S ratio of 0.23 agrees exactly with the value measured for martian dust (67); we estimate the thickness of this dust layer to be about 70 m. The predicted surface abundance of carbon, 290 g/cm(2), is 70 times greater than the atmospheric CO(2) value, but the CaCO(3) content inferred for martian dust (67) could account for at least one-quarter of the predicted value. The past atmospheric pressure, prior to formation of carbonates, could have been as high as 140 mbar, and possibly even 500 mbar. Finally, the predicted (129)Xe/(132)Xe ratio of 2.96 agrees fairly well with the observed value of 2.5(+2)(-1) (85). From the limited data available thus far, a curious dichotomy seems to be emerging among differentiated planets in the inner solar system. Two large planets (Earth and Venus) are fairly rich in

  14. 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

  15. 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....

  16. GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FORM 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....

  17. 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....

  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 60.622 - 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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)...

  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, 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...

  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 60.462 - 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...

  9. 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)...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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....

  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 60.452 - 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 60.492 - 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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....

  4. 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)...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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....

  14. 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...

  15. 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....

  16. 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...

  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 60.622 - 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 60.722 - 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...

  20. 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...

  1. 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...

  2. 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...

  3. High Arctic Biogenic Volatile Organic Compound emissions

    NASA Astrophysics Data System (ADS)

    Schollert, Michelle; Buchard, Sebrina; Faubert, Patrick; Michelsen, Anders; Rinnan, Riikka

    2013-04-01

    Biogenic volatile organic compounds (BVOCs) emitted from terrestrial vegetation participate in oxidative reactions, affecting the tropospheric ozone concentration and the lifetimes of greenhouse gasses such as methane. Also, they affect the formation of secondary organic aerosols. BVOCs thus provide a strong link between the terrestrial biosphere, the atmosphere and the climate. Global models of BVOC emissions have assumed minimal emissions from the high latitudes due to low temperatures, short growing seasons and sparse vegetation cover. However, measurements from this region of the world are lacking and emissions from the High Arctic have not been published yet. The aim of this study was to obtain the first estimates for BVOC emissions from the High Arctic. Hereby, we wish to add new knowledge to the understanding of global BVOC emissions. Measurements were conducted in NE Greenland (74°30' N, 20°30' W) in four vegetation communities in the study area. These four vegetation communities were dominated by Cassiope tetragona, Salix arctica, Vaccinium uliginosum and Kobresia myosuroides/Dryas octopetela/Salix arctica, respectively. Emissions were measured by enclosure technique and collection of volatiles into adsorbent cartridges in August 2009. The volatiles were analyzed by gas chromatography-mass spectrometry following thermal desorption. Isoprene showed highest emissions in S. arctica-dominated heath, where it was the dominant single BVOC. However, isoprene emission decreased below detection limit in the end of August when the temperature was at or below 10°C. According to a principal component analysis, monoterpene and sesquiterpene emissions were especially associated with C. tetragona-dominated heath. Especially S. arctica and C. tetragona dominated heaths showed distinct patterns of emitted BVOCs. Emissions of BVOC from the studied high arctic heaths were clearly lower than the emissions observed previously in subarctic heaths with more dense vegetation

  4. Volatile halocarbon compounds in process water and processed foods

    SciTech Connect

    Uhler, A.D.; Diachenko, G.W.

    1987-10-01

    Volatile halocarbon compounds (VHCs) of low molecular weight are among the most abundant man-made industrial chemicals in the United States. Because of the physical properties of these compounds, in particular their high volatility, they are ubiquitous environmental contaminants. The Environmental Protection Agency (EPA) has detected numerous VHCs in ground water and finished drinking water. The Food and Drug Administration's (FDA's) Division of Contaminants Chemistry, as well as other laboratories, have detected VHCs in foods. These findings of VHCs in foods, coupled with their frequent detection in ground waters, suggested that food contamination by VHCs could be occurring via polluted process waters. The objectives of this investigation were to determine if VHC contamination of food through contact with contaminated process water was widespread, and to ascertain the levels of contamination. The problem was addressed by collecting and analyzing process water and foods from processing plants situated in areas where contamination of the process water was most probable. Recent data from EPA were used to select food processing plants most likely to use VHC-contaminated process water. Processing plants were chosen for study only if they produced a high-fat content food that came in contact with water during processing, or produced a product that contained a high percentage of added water. Findings are reported here in process water and food product analysis from 15 food processing plants located in 9 different states (CA, FL, IL, MA, MI, NY, OH, PA, WI), representing a total of 39 food products.

  5. 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. PMID:26819529

  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. 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.

  8. 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).

  9. Characterizing Abundances of Volatiles in Comets Through Multiwavelength Observations

    NASA Technical Reports Server (NTRS)

    Milam, Stefanie N.; Charnley, Steven B.; Kuan, Yi-Jehng; Chuang, Yo-Ling; DiSanti, Michael A.; Bonev, Boncho P.; Remijan, Anthony J.; Coulson, Iain; Haynes, Lillian; Stenborg, Maria

    2012-01-01

    Recently, there have been complimentary observations from multiple facilities to try to unravel the chemical complexity of comets. Incorporating results from various techniques, including: single-dish millimeter wavelength observations, interferometers, and/or IR spectroscopy, one can gain further insight into the abundances, production rates, distributions, and formation mechanisms of molecules in these objects [I]. Such studies have provided great detail towards molecules with a-typical chemistries, such as H2CO [2]. We report spectral observations of C/2007 N3 (Lulin), C/2009 R1 (McNaught), 103P/Hartley 2, and C/2009 P1 (Garradd) with the Arizona Radio Observatory's SMT and 12-m telescopes, as well as the NRAO Greenbank telescope and IRTF-CSHELL. Multiple parent volatiles (HCN, CH3OH, CO, CH4, C2H6, and H2O) as well as a number of daughter products (CS and OH) have been detected in these objects. We will present a comparison of molecular abundances in these comets to those observed in others, supporting a long-term effort of building a comet taxonomy based on composition. Previous work has revealed a range of abundances of parent species (from "organics-poor" to "organics-rich") with respect to water among comets [3,4,5], however the statistics are still poorly constrained and interpretations of the observed compositional diversity are uncertain. We gratefully acknowledge support from the NSF Astronomy and Astrophysics Program, the NASA Planetary Astronomy Program, NASA Planetary Atmospheres Program, and the NASA Astrobiology Program.

  10. 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. PMID:21121267

  11. 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

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES

    EPA Science Inventory

    The paper discusses the development of a global inventory of anthropogenic volatile organic compound (VOC) emissions. t includes VOC estimates for seven classes of VOCs: paraffins, olefins, aromatics (benzene, toluene, xylene), formaldehyde, other aldehydes, other aromatics, and ...

  3. COMPACT, CONTINUOUS MONITORING FOR VOLATILE ORGANIC COMPOUNDS - PHASE I

    EPA Science Inventory

    Improved methods for onsite measurement of multiple volatile organic compounds are needed for process control, monitoring, and remediation. This Phase I SBIR project sets forth an optical measurement method that meets these needs. The proposed approach provides an instantaneous m...

  4. ODOR AND IRRITATION EFFECTS OF A VOLATILE ORGANIC COMPOUND MIXTURE

    EPA Science Inventory

    Human exposure to volatile organic compounds elicits a variety ofsymptoms, many of which are thought to be mediated by the olfactoryand trigeminal systems. his report describes evidence indicatingthat perceived odor intensity diminishes during prolonged exposure,whearas irritatin...

  5. IMPROVEMENT IN AIR TOXICS METHODS FOR VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    Innovative and customized monitoring methods for air toxic volatile organic compounds (VOCs) are being developed for applications in exposure and trends monitoring. This task addresses the following applications of specific interest:

    o Contributions to EPA Regional Monit...

  6. Volatile organic compound sources for Southern Finland

    NASA Astrophysics Data System (ADS)

    Patokoski, Johanna; Ruuskanen, Taina M.; Kajos, Maija K.; Taipale, Risto; Rantala, Pekka; Aalto, Juho; Ryyppö, Timo; Hakola, Hannele; Rinne, Janne

    2014-05-01

    Volatile organic compounds (VOCs) have several sources, both biogenic and anthropogenic. Emissions of biogenic VOCs in a global scale are estimated to be an order of magnitude higher than anthropogenic ones. However, in densely populated areas and during winter time the anthropogenic VOC emissions dominate over the biogenic ones. The aim of this study was to clarify potential local sources and source areas of VOCs in different seasons. Diurnal behaviour in winter and spring were also compared at two different sites in Finland: SMEAR II and III (Station for Measuring Ecosystem - Atmosphere Relations). SMEAR II is a rural site located in Hyytiälä in Southern Finland 220 km North-West from Helsinki whereas SMEAR III is background urban site located 5 km from the downtown of Helsinki. The volume mixing ratios of VOCs were measured with a proton-transfer-reaction mass spectrometer (PTR-MS, Ionicon Analytik GmbH, Austria) during years 2006-2011. Other trace gases such as CO, NOXand SO2 were also measured in both sites and used for source analysis. Source areas for long term VOC measurements were investigated with trajectory analysis and sources for local and regional concentrations were determined by Unmix multivariate receptor model. Forest fires affect air quality and the biggest smoke plumes can be seen in satellite images and even hinder visibility in the plume areas. They provide temporally and spatially well-defined sources that can be used to verify source area estimates. During the measurement periods two different forest fire episodes with several hotspots, happened in Russia. Forest fires which showed up in these measurements were in 2006 near the border of Finland in Vyborg area and 2010 in Moscow area. Forest fire episodes were clearly observed in trajectory analysis for benzene, toluene and methanol and also CO and NOX. In addition to event sources continuous source areas were determined. Anthropogenic local sources seemed to be dominant during winter in

  7. 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

  8. 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.

  9. Heterogeneous reactions of volatile organic compounds in the atmosphere

    NASA Astrophysics Data System (ADS)

    Shen, Xiaoli; Zhao, Yue; Chen, Zhongming; Huang, Dao

    2013-04-01

    Volatile organic compounds (VOCs) are of central importance in the atmosphere because of their close relation to air quality and climate change. As a significant sink for VOCs, the fate of VOCs via heterogeneous reactions may explain the big gap between field and model studies. These reactions play as yet unclear but potentially crucial role in atmospheric processes. In order to better evaluate this reaction pathway, we present the first specific review for the progress of heterogeneous reaction studies on VOCs, including carbonyl compounds, organic acids, alcohols, and so on. Our review focuses on the processes for heterogeneous reactions of VOCs under varying experimental conditions, as well as their implications for trace gas and HOx budget, secondary organic aerosol (SOA) formation, physicochemical properties of aerosols, and human health. Finally, we propose the future direction for laboratory studies of heterogeneous chemistry of VOCs that should be carried out under more atmospherically relevant conditions, with a special emphasis on the effects of relative humidity and illumination, the multicomponent reaction systems, and reactivity of aged and authentic particles. In particular, more reliable uptake coefficients, based on the abundant elaborate laboratory studies, appropriate calibration, and logical choice criterion, are urgently required in atmospheric models.

  10. 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.

  11. 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

  12. 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... compounds. (a) On and after the date on which the performance test required by § 60.8 has been...

  13. 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... compounds. (a) On and after the date on which the performance test required by § 60.8 has been...

  14. 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... compounds. (a) On and after the date on which the performance test required by § 60.8 has been...

  15. 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... compounds. (a) On and after the date on which the performance test required by § 60.8 has been...

  16. 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... compounds. (a) On and after the date on which the performance test required by § 60.8 has been...

  17. 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 ...

  18. Speciation of volatile organic compounds from poultry production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. DESTRUCTION OF VOLATILE ORGANIC COMPOUNDS VIA CATALYTIC INCINERATION

    EPA Science Inventory

    The paper gives results of an investigation of the effect of catalytic incinerator design and operation the destruction of specific volatile organic compounds (VOCs), both singly and in mixtures. A range of operating and design parameters were tested on a wide variety of compound...

  1. 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

  2. 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

  3. 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. PMID:27596413

  4. Guaianolides and volatile compounds in chamomile tea.

    PubMed

    Tschiggerl, Christine; Bucar, Franz

    2012-06-01

    Chamomile (German Chamomile, Matricaria recutita L., Asteraceae) is one of the most popular medicinal plants in use as an herbal tea for food purposes and in folk medicine. Qualitative and semi-quantitative analyses of the volatile fraction of chamomile herbal tea were performed. Volatile constituents of the infusion were isolated by two different methods, namely hydrodistillation and solid phase extraction (SPE), and analysed by GC-MS. The relative proportions of particular chemical classes, present in the essential oil and volatile fractions of the infusion showed remarkable differences. The proportion of mono- and sesquiterpene hydrocarbons in the infusion, as compared to the essential oil, was significantly lower. Strikingly, the dichloromethane extract of the infusion contained a lower amount of bisabolol oxides and chamazulene, but higher amounts of spiroethers, sesquiterpene lactones and coumarins, as compared to the hydrodistillates of the herbal drug and the infusion. In addition to the previously known guaianolides matricarin and achillin, acetoxyachillin and leucodin (= desacetoxymatricarin), corresponding C-11 stereoisomers with various biological activities typically occurring in Achillea species, were identified in the dichloromethane extract of chamomile tea for the first time. PMID:22410959

  5. 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.

  6. 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. PMID:24583332

  7. Volatile compound profiling of Turkish Divle Cave cheese during production and ripening.

    PubMed

    Ozturkoglu-Budak, S; Gursoy, A; Aykas, D P; Koçak, C; Dönmez, S; de Vries, R P; Bron, P A

    2016-07-01

    The formation of volatile compounds in Turkish Divle Cave cheese produced in 3 different dairy farms was determined during production and ripening, revealing 110 compounds including acids, alcohols, ketones, esters, and terpenes. The presence and concentration of these volatile compounds varied between specific phases of the production and the 120-d ripening process. Smaller differences were also detected between cheeses produced at different farms. Carboxylic acids were established as a major class at the end of ripening. The relative amounts of acids and ketones increased until d 90 of ripening, whereas alcohols increased for the first 30d and tailed off during the remaining part of the ripening process. The level of esters increased gradually until the end of ripening. Butanoic, acetic, and valeric acids, 2-butanol, 2-butanone, 2-heptanone, ethyl butanoate, α-pinene, and toluene were the most abundant compounds, likely contributing to the characteristic aroma of this traditional cheese. PMID:27108178

  8. A comprehensive screen for volatile organic compounds in biological fluids.

    PubMed

    Sharp, M E

    2001-10-01

    A headspace gas chromatographic (GC) screen for common volatile organic compounds in biological fluids is reported. Common GC phases, DB-1 and DB-WAX, with split injection provide separation and identification of more than 40 compounds in a single 20-min run. In addition, this method easily accommodates quantitation. The screen detects commonly encountered volatile compounds at levels below 4 mg%. A control mixture, providing qualitative and semiquantitative information, is described. For comparison, elution of the volatiles on a specialty phase, DB-624, is reported. This method is an expansion and modification of a screen that had been used for more than 20 years. During its first year of use, the expanded screen has proven to be advantageous in routine forensic casework. PMID:11599614

  9. Volatile halogenated compounds and chlorophenols in the Skagerrak

    NASA Astrophysics Data System (ADS)

    Abrahamsson, Katarina; Ekdahl, Anja

    1996-02-01

    A total of 680 seawater samples were collected and analysed for volatile halogenated organic compounds, and 280 seawater samples were analysed for chlorinated phenols in the Skagerrak. The sampling was done along three transects along the Danish west coast on five occasions during the years 1991 to 1993. Pentachlorophenol (PCP) was the only chlorophenol detected on all occasions, which implies that it is transported as a dissolved species rather than particle bound. The results indicate that the origin of PCP in the Skagerrak is the Baltic and the coastal areas of Sweden and Norway. The biogenic volatile halocarbons constitute the largest fraction of the halocarbons in the area. The data support the findings that volatile chloroethenes are naturally produced. Therefore, the Skagerrak acts as a source for these compounds. The flux of the compounds investigated is directed from the sea to the atmosphere except for carbon tetrachloride.

  10. 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.

  11. 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.

  12. Assessment of bacterial mutagenicity methods for volatile and semi-volatile compounds and mixtures

    SciTech Connect

    Claxton, L.D.

    1985-01-01

    Extensive effort has been given to identifying and quantitating the organic genotoxins associated with airborne particles; however, very little is known about the mutagenicity of vapors and gases, especially those associated with ambient air samples. This overview of the literature and recent U.S. Environmental Protection Agency efforts examines some of the critical aspects associated with the bacterial mutagenicity testing of gases and vapors. For example, the sensitivity of the test system depends upon the method of exposure (preincubation, gases over plates, liquid suspension, etc.); and the method-of-choice appears to depend upon vapor pressure and the solubility of the compound under investigation. Also, the selection of test chamber and other materials is very important since plastic petri dishes have been shown to absorb up to 85% of any haloalkane vapors within an exposure chamber. Investigations have also shown the importance of exposure rates, method of gas mixing, role of metabolic activation systems, the occurrence of photoactivation. In ambient studies, the identification and quantitation of volatile organic mutagens is quite difficult; however, due to their abundance these efforts are very important.

  13. 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. PMID:26471521

  14. Aroma volatile compounds from two fresh pineapple varieties in China.

    PubMed

    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

  15. 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

  16. 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. PMID:25919931

  17. Evolution of the volatile compounds of ripened sausages as a function of both storage time and composition of packaging atmosphere.

    PubMed

    Summo, Carmine; Caponio, Francesco; Tricarico, Francesco; Pasqualone, Antonella; Gomes, Tommaso

    2010-11-01

    An experimental investigation was carried out to study the evolution of the volatile compounds of ripened sausages as a function of both storage time (time) and composition of packaging atmosphere (MAP). Ripened sausages, prepared at an industrial plant, were packed applying three different atmosphere compositions and were stored for three months. The obtained data evinced that the evolution of the volatile compounds was significantly related to the variable time more than to the variable MAP. The main volatile compounds were those derived from spices. Among them, Δ3-carene was the most abundant and a significant decrease was observed during storage (p<0.05). The volatile compounds derived from lipid autoxidation showed generally a significant increase during storage, suggesting the raise of lipid oxidation also at low oxygen concentration. Moreover, octanal and nonanal were significantly influenced by the atmosphere composition, with the highest values in samples packed at the lowest CO2 concentration. PMID:20678868

  18. 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.

  19. Modeling emissions of volatile organic compounds from silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Measuring Emissions of Volatile Organic Compounds from Silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. 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...

  2. AERATION TO REMOVE VOLATILE ORGANIC COMPOUNDS FROM GROUND WATER

    EPA Science Inventory

    The interim report presents general information on the use of aeration to remove volatile organic compounds from drinking water for public health reasons. The report illustrates the types of aerators, shows where they are being used, presents a means of estimating aeration perfor...

  3. VOLATILE ORGANIC COMPOUND MODEL (VERSION 1.8) (FOR MICROCOMPUTERS)

    EPA Science Inventory

    Future emissions of volatile organic compounds (VOCs) and costs of their control can be estimated by applying growth factors, emission constraints, control cost functions, and capacity retirement rates to the base line estimates of VOC emissions and industrial VOC source capacity...

  4. Modeling emissions of volatile organic compounds from silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. VOC (VOLATILE ORGANIC COMPOUND) FUGITIVE EMISSION PREDICTIVE MODEL - USER'S GUIDE

    EPA Science Inventory

    The report discusses a mathematical model that can be used to evaluate the effectiveness of various leak detection and repair (LDAR) programs on controlling volatile organic compound (VOC) fugitive emissions from chemical, petroleum, and other process units. The report also descr...

  6. FIELD-DEPLOYABLE MONITORS FOR VOLATILE ORGANIC COMPOUNDS IN AIR

    EPA Science Inventory

    Volatile organic compounds in ambient air are usually estimated by trapping them from air or collecting whole air samples and returning them to a laboratory for analysis by gas chromatography using selective detection. ata do not appear for several days, during which sample integ...

  7. FIELD DEPLOYABLE MONITORS FOR VOLATILE COMPOUNDS IN AIR

    EPA Science Inventory

    Volatile organic compounds in ambient air are usually estimated by trapping them from air or collecting whole air samples and returning them to a laboratory for analysis by gas chromatography using selective detection. ata do not appear for several days, during which sample integ...

  8. PHOTOTHERMAL DESTRUCTION OF THE VAPOR OF VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    The contamination of subsurface soil and groundwater by volatile organic compounds (VOCS) is a pervasive problem in the United States. n-situ soil vapor extraction (SVE) and ex-situ thermal desorption are the most adapted technologies for the remediation of contaminated soil whil...

  9. 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

  10. 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Qualitative analysis of volatile organic compounds on biochar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. DESTRUCTION OF VOLATILE ORGANIC COMPOUNDS VIA CATALYTIC INCINERATION (JOURNAL VERSION)

    EPA Science Inventory

    The paper gives results of an investigation of the effect of catalytic incinerator design and operation on the destruction of specific volatile organic compounds (VOCs), both singly and in mixtures. A range of operating and design parameters were tested on a wide variety of compo...

  15. Residential exposure to volatile organic compounds and asthma.

    PubMed

    Dales, Robert; Raizenne, Mark

    2004-01-01

    We critically analysed the literature concerning exposure to volatile organic compounds and asthma. Observational studies have consistently found a relation between volatile organic compounds and indicators of asthma, such as symptoms, peak flows, and objectively measured bronchial reactivity. In contrast, interventional studies have generally failed to find a relation between exposure to residential levels of formaldehyde and other volatile organic compounds and asthma. One hypothesis to explain the discrepancy in findings between interventional and observational studies is that the effect size is small requiring relatively large numbers of study subjects, common in observational studies but often not feasible in interventional studies. Another hypothesis is that longer duration of exposure is important, a common circumstance in observational studies where the home environment is the exposure setting. In contrast, duration of exposure in interventional studies is usually of minutes-to-hours in a chamber. Finally, the observed association in observational studies could be confounded by a factor which is a determinant of asthma and is also associated with exposure to volatile organic compounds. PMID:15260458

  16. Volatile organic compounds in polyethylene bags-A forensic perspective.

    PubMed

    Borusiewicz, Rafał; Kowalski, Rafał

    2016-09-01

    Polyethylene bags, though not recommended, are sometimes used in some countries as improvised packaging for items sent to be analysed for the presence of volatile organic compounds, namely ignitable liquids residues. Sometimes items made of polyethylene constitute the samples themselves. It is well known what kind of volatile organic compounds are produced as a result of polyethylene thermal decomposition, but there is a lack of information relating to if some volatile compounds are present in unheated/unburned items made of polyethylene in detectable amounts and, if so, what those compounds are. The aim of this presented research was to answer these questions. 28 different bags made of polyethylene, representing 9 brands, were purchased in local shops and analysed according to the procedure routinely used for fire debris. The results proved that in almost all bags a distinctive mixture of compounds is present, comprising of n-alkanes and n-alkenes with an even number of carbon atoms in their molecules. Some other compounds (e.g., limonene, 2,2,4,6,6-pentamethylheptane) are also often present, but the presence of even n-alkanes and n-alkenes constitutes the most characteristic feature. PMID:27458996

  17. 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. PMID:14971492

  18. 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

  19. Bioactivity of volatile organic compounds produced by Pseudomonas tolaasii.

    PubMed

    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

  20. Semivolatile and volatile compounds in combustion of polyethylene.

    PubMed

    Font, Rafael; Aracil, Ignacio; Fullana, Andrés; Conesa, Juan A

    2004-11-01

    The evolution of semivolatile and volatile compounds in the combustion of polyethylene (PE) was studied at different operating conditions in a horizontal quartz reactor. Four combustion runs at 500 and 850 degrees C with two different sample mass/air flow ratios and two pyrolytic runs at the same temperatures were carried out. Thermal behavior of different compounds was analyzed and the data obtained were compared with those of literature. It was observed that alpha,omega-olefins, alpha-olefins and n-paraffins were formed from the pyrolytic decomposition at low temperatures. On the other hand, oxygenated compounds such as aldehydes were also formed in the presence of oxygen. High yields were obtained of carbon oxides and light hydrocarbons, too. At high temperatures, the formation of polycyclic aromatic hydrocarbons (PAHs) took place. These compounds are harmful and their presence in the combustion processes is related with the evolution of pyrolytic puffs inside the combustion chamber with a poor mixture of semivolatile compounds evolved with oxygen. Altogether, the yields of more than 200 compounds were determined. The collection of the semivolatile compounds was carried out with XAD-2 adsorbent and were analyzed by GC-MS, whereas volatile compounds and gases were collected in a Tedlar bag and analyzed by GC with thermal conductivity and flame ionization detectors. PMID:15488924

  1. 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.

  2. Methanol ice VUV photoprocessing: GC-MS analysis of volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Abou Mrad, Ninette; Duvernay, Fabrice; Chiavassa, Thierry; Danger, Grégoire

    2016-05-01

    Next to water, methanol is one of the most abundant molecules in astrophysical ices. A new experimental approach is presented here for the direct monitoring via gas chromatography coupled to mass spectrometry (GC-MS) of a sublimating photoprocessed pure methanol ice. Unprecedentedly, in a same analysis, compelling evidences for the formation of 33 volatile organic compounds are provided. The latter are C1-C6 products including alcohols, aldehydes, ketones, esters, ethers and carboxylic acids. Few C3 and all C4 detected compounds have been identified for the first time. Tentative detections of few C5 and C6 compounds are also presented. GC-MS allows for the first time the direct quantification of C2-C4 photoproducts and shows that their abundances decrease with the increase of their carbon chain length. These qualitative and quantitative measurements provide important complementary results to previous experiments, and present interesting similarities with observations of sources rich in methanol.

  3. 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. PMID:25171504

  4. Volatilization of organotin compounds from estuarine and coastal environments

    SciTech Connect

    Amouroux, D.; Tessier, E.; Donard, O.F.X.

    2000-03-15

    The occurrence and speciation of volatile tin compounds (Sn) have been investigated in a contaminated area of the Arcachon Bay (SW France) and in the water column of the Scheldt (Belgium/Netherlands) and Gironde (SW France) estuaries. This paper describes the application of a multi-isotope analytical method, using gas chromatography and inductively coupled plasma-mass spectrometry. Analytes were collected by cryogenic trapping of the gaseous species. This trapping has allowed the authors to probe volatile tin compounds by detecting both {sup 118}Sn and {sup 120}Sn isotopes. Volatile organic tin compounds have been determined in both sediment and water. They could result from both natural methylation and hybridization processes of inorganic tin and from anthropogenic butyltin derivatives released from ship antifouling paintings which have accumulated in sediments. The most ubiquitous species were found to be the methylated forms of butyltin derivatives. These results suggest that biological and/or chemical methylation mechanisms are likely to occur in sediments and to lead to remobilization of tin species into the water column and subsequently to the atmosphere. Finally, sediment-water and water-atmosphere fluxes have been calculated to assess the potential impact of these processes on the fate of organotin compounds in coastal environments.

  5. Fatty acid composition and volatile compounds of caviar from farmed white sturgeon (Acipenser transmontanus).

    PubMed

    Caprino, Fabio; Moretti, Vittorio Maria; Bellagamba, Federica; Turchini, Giovanni Mario; Busetto, Maria Letizia; Giani, Ivan; Paleari, Maria Antonietta; Pazzaglia, Mario

    2008-06-01

    The present study was conducted to characterize caviar obtained from farmed white sturgeons (Acipenser transmontanus) subjected to different dietary treatments. Twenty caviar samples from fish fed two experimental diets containing different dietary lipid sources have been analysed for chemical composition, fatty acids and flavour volatile compounds. Fatty acid make up of caviar was only minimally influenced by dietary fatty acid composition. Irrespective of dietary treatments, palmitic acid (16:0) and oleic acid (OA, 18:1 n-9) were the most abundant fatty acid followed by docosahexaenoic acid (DHA, 22:6 n-3) and eicopentaenoic (EPA, 20:5 n-3). Thirty-three volatile compounds were isolated using simultaneous distillation-extraction (SDE) and identified by GC-MS. The largest group of volatiles were represented by aldehydes with 20 compounds, representing the 60% of the total volatiles. n-Alkanals, 2-alkenals and 2,4-alkadienals are largely the main responsible for a wide range of flavours in caviar from farmed white surgeon. PMID:18486649

  6. Abundances of cobalt, nickel, and volatiles in the silicate portion of the moon

    NASA Technical Reports Server (NTRS)

    Delano, John W.

    1986-01-01

    The trace abundances of Ni have been determined in 20 high-Mg magmas produced by partial melting of the lunar mantle. Associated with the eruption of the high-Mg magmas was the release of indigenous volatile elements. Data suggest that these volatiles were derived from primordial blocks of debris from the outer solar system that became entrained in the circumterrestrial accretion disk. The survival of these reservoirs within the lunar interior places constraints on the moon's thermal history.

  7. Development of a new semi-volatile organic compound sampler

    SciTech Connect

    Sioutas, C.; Koutrakis, P.; Burton, R.M.

    1994-12-31

    A new sampler has been developed to sample semi-volatile organic compounds. The sampler utilizes the principle of virtual impactor to efficiently separate the particulate from the gas phases of organic compounds. The virtual impactor consists of a slit-shaped nozzle where the aerosol is accelerated, and another slit-shaped nozzle that collects the particulate phase of organics (plus a small and known fraction of the gas phase). The acceleration slit is 0.023 cm wide, the collection slit is 0.035 cm wide, and both slits are 11 cm long. The virtual impactor`s 50% cutpoint has been determined experimentally to be 0.12 {micro}m. In addition, interstage losses have been determined (in all configurations tested, particle losses ranged from 5--15%). The impactor`s sampling flow rate is 284 liters/minute, with a corresponding pressure drop of 100 inches H{sub 2}O. Higher or lower sampling flow rates can be achieved by increasing or decreasing the length of the slits. Tests for volatilization losses have been conducted by generating organic aerosols of known volatility, and comparing the impactor`s collection to that of a filter pack sampling in parallel. The experiments demonstrated negligible volatilization losses (< 5%) for the compounds tried. Particles are collected on a filter connected to the minor flow of the impactor, followed by a sorbent bed to collect material that volatilized from the particles. The organic gas phases is collected on a sorbent bed, connected to the major flow of the impactor.

  8. 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

  9. An alternative method based on enzymatic fat hydrolysis to quantify volatile compounds in wheat bread crumb.

    PubMed

    Pico, Joana; Nozal, María Jesús; Gómez, Manuel; Bernal, José Luis

    2016-09-01

    An alternative method to quantify 40 volatile compounds in wheat bread crumb is proposed. It consists of a Soxhlet extraction with a mixture of dichloromethane and diethyl ether containing lipases and a subsequent concentration with Vigreux column. It is the first time that lipases are added to transform the fat into free fatty acids and glycerol, which elute at the end of the chromatogram after the analytes, avoiding problems in the chromatography due to fat residues, such as dirtiness in the injector, column clogging or overlapping peaks. The extract is most easily analysed by GC/MS, using a standard addition method to correct matrix effect. The method was fully validated, with extraction efficiencies between 70% and 100% and precision RSD lower than 15%. The method was applied to a commercial crumb, with acetoin, phenylethyl alcohol and acetic acid as highly abundant compounds, which are considered main volatiles in crumb. PMID:27041305

  10. Emission of volatile organic compounds from silage: Compounds, sources, and implications

    NASA Astrophysics Data System (ADS)

    Hafner, Sasha D.; Howard, Cody; Muck, Richard E.; Franco, Roberta B.; Montes, Felipe; Green, Peter G.; Mitloehner, Frank; Trabue, Steven L.; Rotz, C. Alan

    2013-10-01

    Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) 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 rates and identify practices that could reduce emissions. Through a literature review, we have focused on identifying the most important compounds emitted from corn silage (the most common type of silage in the US) and the sources of these compounds by quantifying their production and emission potential in silage and describing production pathways. We reviewed measurements of VOC emission from silage and assessed the importance of individual silage VOCs through a quantitative analysis of VOC concentrations within silage. Measurements of VOC emission from silage and VOCs present within silage indicated that alcohols generally make the largest contribution to emission from corn silage, in terms of mass emitted and potential ozone formation. Ethanol is the dominant alcohol in corn silage; excluding acids, it makes up more than half of the mean mass of VOCs present. Acids, primarily acetic acid, may be important when emission is high and all VOCs are nearly depleted by emission. Aldehydes and esters, which are more volatile than acids and alcohols, are important when exposure is short, limiting emission of more abundant but less volatile compounds. Variability in silage VOC concentrations is very high; for most alcohols and acids, tolerance intervals indicate that 25% of silages have concentrations a factor of two away from median values, and possibly much further. This observation suggests that management practices can significantly influence VOC concentrations. Variability also makes prediction of emissions difficult. The most important acids, alcohols, and aldehydes present in silage are probably produced by bacteria (and, in the case of ethanol, yeasts) during fermentation and

  11. Influence of type of muscle on volatile compounds throughout the manufacture of Celta dry-cured ham.

    PubMed

    Bermúdez, Roberto; Franco, Daniel; Carballo, Javier; Lorenzo, José M

    2015-12-01

    The effect of muscle type on volatile compounds throughout the manufacture of Celta dry-cured ham was studied. Thirty Celta ham were taken from the fresh pieces, after the end of the salting stage, after 120 days of post-salting, after the end of drying-ripening stage, and after 165 and 330 days of "bodega" step. The volatile compounds from semimembranosus (SM) and biceps femoris (BF) muscles were extracted by using headspace-solid phase microextraction (SPME) and analysed by gas chromatographic/mass spectrometry (GC/MS). Fifty-five volatile compounds were identified and quantified. The number of volatile compounds increased during the different steps of the process, reaching at 550 days of process 39 and 40 volatile compounds in SM and BF muscles, respectively. Results indicated that the most abundant chemical family in flavour at the end of the manufacturing process were esters in the two muscles studied, followed by aliphatic hydrocarbons and aldehydes. During the manufacturing process, an increase in the total amount of volatile compounds was observed, being this increase more marked in samples from BF muscle (from 550.7 to 1118.9 × 10(6) area units) than in samples from SM muscle (from 459.3 to 760.4 × 10(6) area units). Finally, muscle type displayed significant (P < 0.05) differences for four esters, two alcohols, one aldehyde, one ketone and four aliphatic hydrocarbons. PMID:25331495

  12. Development of volatile compounds during the manufacture of dry-cured "lacón," a Spanish traditional meat product.

    PubMed

    Purriños, Laura; Bermúdez, Roberto; Franco, Daniel; Carballo, Javier; Lorenzo, José M

    2011-01-01

    Volatile compounds were determined throughout the manufacture of dry-cured "lacón," a traditional dry-salted, and ripened meat product made in the north-west of Spain from the foreleg of the pig following a similar process to that of dry-cured ham. Volatiles were extracted by a purge-and-trap method and analyzed by gas chromatographic/mass spectrometry. One hundred and two volatile compounds were identified. In raw material, only 34 volatile compounds were found and at very low levels. The number of volatile compounds increased during processing. The substances identified belonged to several chemical classes: aldehydes (23), alcohols (9), ketones (15), hydrocarbons (37), esters (4), acids (3), furans (4), sulphur compounds (1), chloride compounds (1), and other compounds (4). Results indicated that the most abundant chemical family in flavor at the end of the manufacturing process was aldehydes, followed by hydrocarbons and ketones. Lipids were the most important precursor of flavor compounds of dry-cured "lacón." PMID:21535660

  13. Volatile and polar compounds in Rosadamascena Mill 1803 cell suspension.

    PubMed

    Pavlov, Atanas; Popov, Simeon; Kovacheva, Elena; Georgiev, Milen; Ilieva, Mladenka

    2005-07-21

    Studies were conducted on low molecular metabolites (volatiles and polar compounds) produced by Rosa damascena Mill 1803 cell suspension culture, cultivated under different regimes: as a free suspension (in flasks and in bioreactor) and in a two-phase system (in the presence of Amberlite XAD-4 as a second phase). It was established that the main groups of volatiles were hydrocarbons and free acids and their esters and only traces of terpenoids were found. The main components of polar fraction were free acids, especially amino acids and oxidized acids. Depending on the culture conditions, significant differences were established in the amounts of all compounds under study in biomasses, culture media and adsorbed on the second phase (Amberlite XAD-4). PMID:15899533

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

    PubMed

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

    2012-11-01

    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. PMID:23072649

  15. Analytical methods for volatile compounds in wheat bread.

    PubMed

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

    2016-01-01

    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. PMID:26452307

  16. Volatile organic compounds in the atmosphere of forests

    NASA Astrophysics Data System (ADS)

    Isidorov, V. A.; Zenkevich, I. G.; Ioffe, B. V.

    The procedure of sampling and gas chromatographic-mass spectrometric analysis of air containing volatile emissions from living plants has been elaborated. The qualitative composition of volatile organic compounds (VOC) produced by 22 species of plants which are characteristic for Northern hemisphere forests has been studied. The emission rate of isoprene and terpenes for some of them has been determined. Terpene concentrations in coniferous forests of different regions of the U.S.S.R. have been also determined. The list of compounds identified includes more than 70 substances of different classes. Total terpene concentrations in the coniferous forests air usually vary from 3.5 to 35 μg -3. Strong influence of meteorological conditions on the emission rate and terpene concentrations in the air under the forest canopy has been noted.

  17. Odor and irritation effects of a volatile organic compound mixture

    SciTech Connect

    Hudnell, H.K.; Otto, O.D.; Mohave, L.; House, D.E.

    1990-01-01

    Human exposure to volatile organic compounds elicits a variety of symptoms, many of which are thought to be mediated by the olfactory and trigeminal systems. The report describes evidence indicating that perceived odor intensity diminishes during prolonged exposure, whereas irritation of the eyes and throat reaches an asymptotic level. Both odor and irritation appear to influence the assessment of air quality. Results of the study will be used in designing future indoor air studies related to sick building syndrome.

  18. 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. PMID:26243901

  19. 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

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

    PubMed

    Bennett, Joan W; Inamdar, Arati A

    2015-09-01

    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

  1. 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.

  2. Headspace gas chromatography-mass spectrometry of volatile compounds in murici (Byrsonima crassifolia l. Rich).

    PubMed

    Alves, G L; Franco, M R B

    2003-01-24

    Northern and Northeastern Brazil have a natural diversity of fruits, many of which are considered exotic, presenting different flavors and aromas. The enormous diversity of fruits represents a promising area for research on aromas. There is also a great potential for the manufacture of juices, desserts or other processed products. Murici is a typical fruit from these regions presenting a different flavor, reminiscent of that of cheese. This fruit is consumed mainly as juice, ice cream or as liquor, greatly appreciated by the local population. Headspace volatile compounds of three lots of the fruit from Ceará (Fortaleza) were collected by suction on Porapak Q for 2 h and desorbed with 300 microl of acetone. The isolated volatile compounds were separated by high resolution GC. Forty-six volatile compounds were detected, of which 41 were identified by gas chromatography-mass spectrometry and Kovats indices. The most abundant compounds were ethanol (28.3%) and ethyl hexanoate (25.1%). Butanoic acid (5.1%), hexanoic acid (5.1%) and methyl butyrate (2.8%) were also detected in the headspace of the fruit and confirm its unusual cheese aroma. PMID:12580497

  3. [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. PMID:27266255

  4. 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.

  5. Abundances of sodium, sulfur, and potassium in lunar volcanic glasses: Evidence for volatile loss during eruption

    NASA Technical Reports Server (NTRS)

    Delano, J. W.; Mcguire, J.

    1992-01-01

    Six varieties of lunar volcanic glass are known to occur within the Apollo 17 sample collection. Investigations have shown that 25 volatile elements are known to be concentrated on the exterior surfaces of individual volcanic glass spheres. Since bulk analyses of volcanic glass provide an integrated abundance of an element on and with the glass spherules, other methods must be relied on to determine the interior abundance of an element. The interior abundance of an element with a volcanic glass sphere establishes the abundance of that element in the melt at the time of quench. The current study is part of a comprehensive attempt to measure the abundance of three volatile elements (Na, S, and K) within representative spheres of the 25 varieties of lunar volcanic glass currently known to exist at the Apollo landing sites. Comparison of the measured abundances of these elements within the interiors of individual glasses with bulk analyses and crystalline mare basalts will furnish new constraints on the geochemical behavior of volatile elements during lunar mare volcanism.

  6. Volatile-bearing phases in carbonaceous chondrites: Compositions, modal abundance, and reaction kinetics

    NASA Technical Reports Server (NTRS)

    Ganguly, Jibamitra

    1990-01-01

    The spectral and density characteristics of Phobos and Deimos (the two small natural satellites of Mars) strongly suggest that a significant fraction of the near-earth asteroids are made of carbonaceous chondrites, which are rich in volatile components and, thus, could serve as potential resources for propellants and life supporting systems in future planetary missions. However, in order to develop energy efficient engineering designs for the extraction of volatiles, knowledge of the nature and modal abundance of the minerals in which the volatiles are structurally bound and appropriate kinetic data on the rates of the devolatilization reactions is required. Theoretical calculations to predict the modal abundances and compositions of the major volatile-bearing and other mineral phases that could develop in the bulk compositions of C1 and C2 classes (the most volatile rich classes among the carbonaceous chondrites) were performed as functions of pressure and temperature. The rates of dehydration of talc at 585, 600, 637, and 670 C at P(total) = 1 bar were determine for the reaction: Talc = 3 enstatite + quartz + water. A scanning electron microscopic study was conducted to see if the relative abundance of phases can be determined on the basis of the spectral identification and x ray mapping. The results of this study and the other studies within the project are discussed.

  7. Detection of volatile organic compounds using porphyrin derivatives.

    PubMed

    Dunbar, A D F; Brittle, S; Richardson, T H; Hutchinson, J; Hunter, C A

    2010-09-16

    Seven different porphyrin compounds have been investigated as colorimetric gas sensors for a wide range of volatile organic compounds. The porphyrins examined were the free base and Mg, Sn, Zn, Au, Co, and Mn derivatives of 5,10,15,20-tetrakis[3,4-bis(2-ethylhexyloxy)phenyl]-21H,23H-porphine. Chloroform solutions of these materials were prepared and changes in their absorption spectra induced by exposure to various organic compounds measured. The porphyrins that showed strong responses in solution were selected, and Langmuir-Blodgett films were prepared and exposed to the corresponding analytes. This was done to determine whether they are useful materials for solid state thin film colorimetric vapor sensors. Porphyrins that readily coordinate extra ligands are shown to be suitable materials for colorimetric volatile organic compound detectors. However, porphyrins that already have bound axial ligands when synthesized only show a sensor response to those analytes that can substitute these axial ligands. The Co porphyrin displays a considerably larger response than the other porphyrins investigated which is attributed to a switch between Co(II) and Co(III) resulting in a large spectral change. PMID:20735119

  8. 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.

  9. 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.

  10. Urinary volatile compounds as biomarkers for lung cancer.

    PubMed

    Hanai, Yosuke; Shimono, Ken; Matsumura, Koichi; Vachani, Anil; Albelda, Steven; Yamazaki, Kunio; Beauchamp, Gary K; Oka, Hiroaki

    2012-01-01

    Lung cancer is a leading cause of deaths in cancer. Hence, developing early-stage diagnostic tests that are non-invasive, highly sensitive, and specific is crucial. In this study, we investigated to determine whether biomarkers derived from urinary volatile organic compounds (VOCs) can be used to discriminate between lung cancer patients and normal control patients. The VOCs were extracted from the headspace by solid-phase microextraction and were analyzed by gas chromatography time-of-flight mass spectrometry. Nine putative volatile biomarkers were identified as elevated in the lung cancer group. Receiver operating characteristic curve analysis was also performed, and the markers were found to be highly sensitive and specific. Next we used principal component analysis (PCA) modeling to make comparisons compare within the lung cancer group, and found that 2-pentanone may have utility in differentiating between adenocarcinoma and squamous cell carcinomas. PMID:22484930

  11. Marine Vibrio Species Produce the Volatile Organic Compound Acetone

    PubMed Central

    Nemecek-Marshall, M.; Wojciechowski, C.; Kuzma, J.; Silver, G. M.; Fall, R.

    1995-01-01

    While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine but not the other common amino acids, suggesting that leucine degradation leads to acetone formation. Acetone production by marine vibrios may contribute to the dissolved organic carbon associated with phytoplankton, and some of the acetone produced may be volatilized to the atmosphere. PMID:16534920

  12. 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.

  13. Correction for volatile fractionation in ascending magmas: noble gas abundances in primary mantle melts

    NASA Astrophysics Data System (ADS)

    Burnard, Pete

    2001-09-01

    Accurate relative noble gas abundances of mantle-derived melts are required in order to further understand the distribution of noble gases in the mantle and fractionation of noble gases during the melting process. Noble gas relative abundances in the majority of oceanic basalts are highly fractionated, at least in part due to late stage, solubility controlled fractionation. Noble gas concentrations in the volatile phase (≡ noble gas:CO 2 ratio) will vary systematically during solubility controlled degassing of a magma. This contribution models the noble gas concentrations in the volatile phase during degassing at different pressures and vesicularities in order to develop a method for correcting fractionation resulting from magmatic degassing, and thereby estimate the "initial" (pre-degassing) noble gas compositions. Correcting for fractionation during magmatic degassing requires: a) a method for determining the volatile fractionation trajectory during degassing; and b) one well constrained mantle volatile composition with which to "fix" the extrapolation. The trajectory of volatile fractionation can be estimated by sequential crushing of basaltic glasses. Vesicles grow during ascent, therefore large vesicles trap early (less fractionated) volatiles while small vesicles trap late (fractionated) volatiles. Sequential crushing of basaltic glasses releases volatiles from progressively smaller vesicles, thereby allowing the fractionation trajectory resulting from degassing to be determined on individual samples. The production rate of both 21Ne and 4He in the mantle is a function of U concentration only, resulting in a constant 21Ne/ 4He production ratio in the mantle which can be used to "fix" the degassing fractionation trajectory determined by sequential crushing. This correction then allows fractionation of 4He from 40Ar prior to degassing to be assessed. This method is illustrated using multiple crushes of a single basaltic glass from the mid-Atlantic Ridge that

  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. Large drought-induced variations in oak leaf volatile organic compound emissions during PINOT NOIR 2012

    SciTech Connect

    Geron, Chris; Gu, Lianhong; Daly, Ryan; Harley, Peter; Rasmussen, Rei; Seco, Roger; Guenther, Alex; Karl, Thomas

    2015-12-17

    Here, leaf-level isoprene and monoterpene emissions were collected and analyzed from five of the most abundant oak (Quercus) species in Central Missouri's Ozarks Region in 2012 during PINOT NOIR (Particle Investigations at a Northern Ozarks Tower – NOx, Oxidants, Isoprene Research). June measurements, prior to the onset of severe drought, showed isoprene emission rates and leaf temperature responses similar to those previously reported in the literature and used in Biogenic Volatile Organic Compound (BVOC) emission models. During the peak of the drought in August, isoprene emission rates were substantially reduced, and response to temperature was dramatically altered, especially for the species in the red oak subgenus (Erythrobalanus).

  17. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. 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. PMID:22751077

  20. Characterizations of volatile organic compounds during high ozone episodes in Beijing, China.

    PubMed

    An, Jun-lin; Wang, Yue-si; Wu, Fang-kun; Zhu, Bin

    2012-04-01

    Air samples were collected in Beijing from June through August 2008, and concentrations of volatile organic compounds (VOCs) in those samples are here discussed. This sampling was performed to increase understanding of the distributions of their compositions, illustrate the overall characteristics of different classes of VOCs, assess the ages of air masses, and apportion sources of VOCs using principal compound analysis/absolute principal component scores (PCA/APCS). During the sampling periods, the relative abundance of the four classes of VOCs as determined by the concentration-based method was different from that determined by the reactivity approach. Alkanes were found to be most abundant (44.3-50.1%) by the concentration-based method, but aromatic compounds were most abundant (38.2-44.5%) by the reactivity approach. Aromatics and alkenes contributed most (73-84%) to the ozone formation potential. Toluene was the most abundant compound (11.8-12.7%) during every sampling period. When the maximum incremental reactivity approach was used, propene, toluene, m,p-xylene, 1-butene, and 1,2,4-trimethylbenzene were the five most abundant compounds during two sampling periods. X/B, T/B, and E/B ratios in this study were lower than those found in other cities, possibly due to the aging of the air mass at this site. Four components were extracted from application of PCA to the data. It was found that the contribution of vehicle exhaust to total VOCs accounted for 53% of VOCs, while emissions due to the solvent use contributed 33% of the total VOCs. Industrial sources contributed 3% and biogenic sources contributed 11%. The results showed that vehicle exhausts (i.e., unburned vehicle emissions + vehicle internal engine combustion) were dominant in VOC emissions during the experimental period. The solvent use made the second most significant contribution to ambient VOCs. PMID:21552987

  1. 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

  2. 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.

  3. Emission of volatile organic compounds from silage: compounds, sources, and implications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. 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).

  5. 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%). PMID:26996031

  6. Measurement of volatile plant compounds in field ambient air by thermal desorption-gas chromatography-mass spectrometry.

    PubMed

    Cai, Xiao-Ming; Xu, Xiu-Xiu; Bian, Lei; Luo, Zong-Xiu; Chen, Zong-Mao

    2015-12-01

    Determination of volatile plant compounds in field ambient air is important to understand chemical communication between plants and insects and will aid the development of semiochemicals from plants for pest control. In this study, a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method was developed to measure ultra-trace levels of volatile plant compounds in field ambient air. The desorption parameters of TD, including sorbent tube material, tube desorption temperature, desorption time, and cold trap temperature, were selected and optimized. In GC-MS analysis, the selected ion monitoring mode was used for enhanced sensitivity and selectivity. This method was sufficiently sensitive to detect part-per-trillion levels of volatile plant compounds in field ambient air. Laboratory and field evaluation revealed that the method presented high precision and accuracy. Field studies indicated that the background odor of tea plantations contained some common volatile plant compounds, such as (Z)-3-hexenol, methyl salicylate, and (E)-ocimene, at concentrations ranging from 1 to 3400 ng m(-3). In addition, the background odor in summer was more abundant in quality and quantity than in autumn. Relative to previous methods, the TD-GC-MS method is more sensitive, permitting accurate qualitative and quantitative measurements of volatile plant compounds in field ambient air. PMID:26493981

  7. Volatile and semi-volatile organic compounds of respiratory health relevance in French dwellings.

    PubMed

    Dallongeville, A; Costet, N; Zmirou-Navier, D; Le Bot, B; Chevrier, C; Deguen, S; Annesi-Maesano, I; Blanchard, O

    2016-06-01

    Over the last decades, the prevalence of childhood respiratory conditions has dramatically increased worldwide. Considering the time spent in enclosed spaces, indoor air pollutants are of major interest to explain part of this increase. This study aimed to measure the concentrations of pollutants known or suspected to affect respiratory health that are present in dwellings in order to assess children's exposure. Measurements were taken in 150 homes with at least one child, in Brittany (western France), to assess the concentrations of 18 volatile organic compounds (among which four aldehydes and four trihalomethanes) and nine semi-volatile organic compounds (seven phthalates and two synthetic musks). In addition to descriptive statistics, a principal component analysis (PCA) was used to investigate grouping of contaminants. Formaldehyde was highly present and above 30 μg/m(3) in 40% of the homes. Diethyl phthalate, diisobutyl phthalate, and dimethylphthalate were quantified in all dwellings, as well as Galaxolide and Tonalide. For each chemical family, the groups appearing in the PCA could be interpreted in term of sources. The high prevalence and the levels of these compounds, with known or suspected respiratory toxicity, should question regulatory agencies to trigger prevention and mitigation actions. PMID:26010323

  8. 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.

  9. Meteoritic Constraints on Models of the Solar Nebula: The Abundances of Moderately Volatile Elements

    NASA Technical Reports Server (NTRS)

    Cassen, P.; Cuzzi, Jeffrey N. (Technical Monitor)

    1994-01-01

    The "moderately volatile" elements are those which condense (or evaporate) in the temperature range 650 - 1350 K, as a mix of material with solar abundances is cooled (or heated) under equilibrium conditions. Their relative abundances in chondritic meteorites are solar (or "cosmic", as defined by tile composition of CI meteorites) to within a factor of several, but vary within that range in a way that correlates remarkably well with condensation temperature, independent of chemical affinity. It has been argued that this correlation reflects a systematically selective process which favored the accretion of refractory material over volatile material from a cooling nebula. Wasson and Chou suggested that condensation and settling of solids contemporaneously with the cooling and removal of nebular gas could produce tile observed abundance patterns, but a quantitative model has been lacking. We show that the abundance patterns of the moderately volatile elements in chondritic meteorites can be produced, in some degree of quantitative detail, by models of the solar nebula that are designed to conform to observations of T Tauri stars and the global conservation laws. For example, even if the local surface density of the nebula is not decreasing, condensation and accretion of solids from radially inflowing gas in a cooling nebula can result in depletions of volatiles, relative to refractories, like those observed. The details of the calculated abundance patterns depend on (but are not especially sensitive to) model parameters, and can exhibit the variations that distinguish the meteorite classes. Thus it appears that nebula characteristics Such as cooling rates, radial flow velocities, and particle accumulation rates can be quantitatively constrained by demanding that they conform to meteoritic data; and the models, in turn, can produce testable hypotheses regarding the time and location of the formation of the chondrite parent bodies and the planets.

  10. Meteoritic Constraints on Models of the Solar Nebula: The Abundances of Moderately Volatile Elements

    NASA Technical Reports Server (NTRS)

    Cassen, Patrick; Cuzzi, Jeff (Technical Monitor)

    1994-01-01

    The "moderately volatile" elements are those which condense (or evaporate) in the temperature range 650 - 1350 K, as a mix of material with solar abundances is cooled (or heated) tinder equilibrium conditions. Their relative abundances in chondritic meteorites are solar (or "cosmic", as defined by the composition of Cl meteorites) to within a factor of several, but vary within that range in a way that correlates remarkably well with condensation temperature, independent of chemical affinity. It has been argued that this correlation reflects a systematically selective process which favored the accretion of refractory material over volatile material from a cooling nebula. Wasson and Chou (Meteoritics 9, 69-94, 1974, and Wasson and co-authors in subsequent papers) suggested that condensation and settling of solids contemporaneously with the cooling and removal of nebular gas could produce the observed abundance patterns, but a quantitative model has been lacking. We show that the abundance patterns of the moderately volatile elements in chondritic meteorites can be produced, in some degree of quantitative detail, by models of the solar nebula that are designed to conform to observations of T Tauri stars and the global conservation laws. For example, even if the local surface density of the nebula is not decreasing, condensation and accretion of solids from radially inflowing gas in a cooling nebula can result in depletions of volatiles, relative to refractories, like those observed, The details of the calculated abundance patterns depend on (but are not especially sensitive to) model parameters, and can exhibit the variations that distinguish the meteorite classes. Thus it appears that nebula characteristics such as cooling rates, radial flow velocities, and particle accumulation rates can be quantitatively constrained by demanding that they conform to meteoritic data; and the models, in turn, can produce testable hypotheses regarding the time and location of the

  11. 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.

  12. 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. PMID:11605854

  13. Challenges and solutions for biofiltration of hydrophobic volatile organic compounds.

    PubMed

    Cheng, Yan; He, Huijun; Yang, Chunping; Zeng, Guangming; Li, Xiang; Chen, Hong; Yu, Guanlong

    2016-11-01

    Volatile organic compounds (VOCs) emitted to the environment highly probably result in ecological and health risks. Many biotechnologies for waste gases containing hydrophobic VOCs have been developed in recent years. However, these biological processes usually exhibit poor removal performances for hydrophobic VOCs due to the low bioavailability. This review presents an overview of enhanced removal of hydrophobic VOCs in biofilters. Mechanisms and problems relevant to the biological removal of hydrophobic VOCs are reviewed, and then solutions including the addition of surfactants, application of fungal biocatalysts, biofiltration with pretreatment, innovative bioreactors and utilization of hydrophilic compounds are discussed in detail. Future research needs are also proposed. This review provides new insights into hydrophobic VOC removal by biofiltration. PMID:27374790

  14. Volatile compounds of raspberry fruit: from analytical methods to biological role and sensory impact.

    PubMed

    Aprea, Eugenio; Biasioli, Franco; Gasperi, Flavia

    2015-01-01

    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. PMID:25647579

  15. Blood volatile compounds as biomarkers for colorectal cancer.

    PubMed

    Wang, Changsong; Li, Peng; Lian, Ailing; Sun, Bo; Wang, Xiaoyang; Guo, Lei; Chi, Chunjie; Liu, Shanshan; Zhao, Wei; Luo, Suqi; Guo, Zhigang; Zhang, Yang; Ke, Chaofu; Ye, Guozhu; Xu, Guowang; Zhang, Fengmin; Li, Enyou

    2014-02-01

    Many recent studies have focused on the connection between the composition of specific volatile organic compounds (VOCs) in exhaled breath and various forms of cancer. However, the composition of exhaled breath is affected by many factors, such as lung disease, smoking, and diet. VOCs are released into the bloodstream before they are exhaled; therefore, the analysis of VOCs in blood will provide more accurate results than the analysis of VOCs in exhaled breath. Blood were collected from 16 colorectal cancer patients and 20 healthy controls, then solid phase microextraction-chromatography-mass spectrometry (SPME-GC-MS) was used to analysis the exhaled volatile organic compounds (VOCs). The statistical methods principal component analysis (PCA) and partial least-squares discriminant analysis (PLSDA) were performed to deal with the final dates. Three metabolic biomarkers were found at significantly lower levels in the group of CRC patients than in the normal control group (P<0.01): phenyl methylcarbamate, ethylhexanol, and 6-t-butyl-2,2,9,9-tetramethyl-3,5-decadien-7-yne. In addition, significantly higher levels of 1,1,4,4-tetramethyl-2,5-dimethylene-cyclohexane were found in the group of CRC patients than in the normal control group (P<0.05). Compared with healthy individuals, patients with colorectal adenocarcinoma exhibited a distinct blood metabolic profile with respect to VOCs. The analysis of blood VOCs appears to have potential clinical applications for CRC screening. PMID:24100612

  16. 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). PMID:23609116

  17. Environmental and biological monitoring of volatile organic compounds in the workplace.

    PubMed

    Caro, J; Gallego, M

    2009-10-01

    The exposure of workers to volatile organic compounds (VOCs) in the workplace has been evaluated in four different occupations, namely: house painters, varnishing workers, car painters and petrol station workers. The study was carried out by analyzing the ambient air within the workers' breathing zone as well as the alveolar air of these workers, which was selected as the biomarker of exposure. Twenty six VOCs were measured in the air samples. Nearly all target VOCs were found in the ambient air of the workplaces assessed, usually involving in the most abundant compounds, toluene, o-xylene and N-butyl acetate, concentrations between 60 and 51,110 microg m(-3). The same VOCs were found in the alveolar air of workers after their work shift, at concentrations whose amount depended on the compound and occupation involved. Toluene, at concentrations between 90 and 29,840 microg m(-3), o-xylene, between 30 and 12,285 microg m(-3), and N-butyl acetate, between 10 and 8045 microg m(-3), were also the most abundant compounds found in the alveolar air of workers after exposure. The post-work concentrations of VOCs in alveolar air correlated significantly with ambient air concentrations, obtaining correlation coefficients over 0.9 for the compounds studied. Furthermore, a general trend towards greater absorption of benzene derivatives by the human body (the average percentage of absorption is 50%) than that of esters (average percentage of 20%) has been observed in the data obtained throughout the study. PMID:19635627

  18. Volatile compounds responsible for aroma of Jutrzenka liquer wine.

    PubMed

    Jeleń, Henryk H; Majcher, Małgorzata; Dziadas, Mariusz; Zawirska-Wojtasiak, Renata; Czaczyk, Katarzyna; Wąsowicz, Erwin

    2011-10-21

    Jutrzenka is a sweet liquer wine produced in Poland from the grape variety of the same name, developed in Poland to withstand the harsh climate of winery regions. Jutrzenka wine has a characteristic aroma with strong fruity and flowery notes, which make it unique among other liquer wines as demonstrated in sensory profile analysis. The work was aimed at characterization of volatile compounds in this wine, with the emphasis on characterization of compounds responsible for its unique aroma. Gas chromatography-olfactometry (GC-O) was applied to identify the key odorants using aroma extract dilution analysis (AEDA) approach. To facilitate free and bound terpenes and C(13)-norisoprenoids identification solid phase extraction (SPE) was used followed by GC/MS. Among identified key odorants β-damascenone was the compound having the highest FD (4096), followed by isoamyl alcohol, 4-mercapto-4-methyl-2-pentanone (FD=2048), methional, linalool, ethyl decanoate (FD=1024) and ethyl hexanoate, furaneol (FD=512). Other significant compounds were ethyl 2-methyl propanoate, ethyl 2-methylbutanoate and phenyl ethyl alcohol. Determination of odor activity values (OAV) showed the highest values for β-damascenone (566), 4-mercapto-4-methyl-2-pentanone (288) ethyl hexanoate (32) and linalool (7). Jutrzenka exhibited also a rich profile of free, and to lesser extent bound terpenes. PMID:21831389

  19. 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

  20. 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. PMID:21788060

  1. Commuter exposure to volatile organic compounds under different driving conditions

    NASA Astrophysics Data System (ADS)

    Jo, Wan-Kuen; Park, Kun-Ho

    The driving conditions that were tested for the in-vehicle concentrations of selected volatile organic compounds (VOCs) included transport modes, fuel distributions, vehicle ventilation conditions, driving routes, commute seasons, car models, and driving periods. This study involved two sampling seasons (winter and summer). The in-auto/in-bus/fixed site ratio of the wintertime mean concentrations was about 6/3/1 for total VOCs and 8/3/1 for benzene. On the median, the in-auto/in-bus exposure ratio ranged from 1.5 to 2.8 for the morning commutes, and ranged from 2.4 to 4.5 for evening commutes, depending on the target compounds. The wintertime in-auto concentrations were significantly higher ( p<0.05), on the average 3-5 times higher, in a carbureted engine than in the three electronic fuel-injected cars. For the summertime in-auto concentrations of the target compounds except benzene, there were no significant differences between low and high ventilation conditions on the two urban routes. The urban in-auto benzene concentration was significantly higher ( p<0.05) under the low ventilation condition. For the rural commutes, the in-auto concentrations of all target compounds were significantly higher ( p<0.05) under the low ventilation condition. The in-auto VOC concentrations on the two urban routes did not differ significantly, and they were greater than the rural in-auto concentrations, with the differences being significant ( p<0.05) for all target compounds. The summertime in-auto concentrations of benzene and toluene were greater than the wintertime in-auto concentrations, with the difference being significant ( p<0.05), while the concentrations of the other target compounds were not significantly different between the two seasons. Neither car models nor driving periods influenced the in-auto VOC concentrations.

  2. 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

  3. Reproductive endocrine patterns and volatile urinary compounds of Arctictis binturong: discovering why bearcats smell like popcorn

    NASA Astrophysics Data System (ADS)

    Greene, Lydia K.; Wallen, Timothy W.; Moresco, Anneke; Goodwin, Thomas E.; Drea, Christine M.

    2016-06-01

    Members of the order Carnivora rely on urinary scent signaling, particularly for communicating about reproductive parameters. Here, we describe reproductive endocrine patterns in relation to urinary olfactory cues in a vulnerable and relatively unknown viverrid—the binturong ( Arctictis binturong). Female binturongs are larger than and dominate males, and both sexes engage in glandular and urinary scent marking. Using a large ( n = 33), captive population, we collected serum samples to measure circulating sex steroids via enzyme immunoassay and urine samples to assay volatile chemicals via gas chromatography-mass spectrometry. Male binturongs had expectedly greater androgen concentrations than did females but, more unusually, had equal estrogen concentrations, which may be linked to male deference. Males also expressed a significantly richer array of volatile chemical compounds than did females. A subset of these volatile chemicals resisted decay at ambient temperatures, potentially indicating their importance as long-lasting semiochemicals. Among these compounds was 2-acetyl-1-pyrroline (2-AP), which is typically produced at high temperatures by the Maillard reaction and is likely to be responsible for the binturong's characteristic popcorn aroma. 2-AP, the only compound expressed by all of the subjects, was found in greater abundance in males than females and was significantly and positively related to circulating androstenedione concentrations in both sexes. This unusual compound may have a more significant role in mammalian semiochemistry than previously appreciated. Based on these novel data, we suggest that hormonal action and potentially complex chemical reactions mediate communication of the binturong's signature scent and convey information about sex and reproductive state.

  4. Reproductive endocrine patterns and volatile urinary compounds of Arctictis binturong: discovering why bearcats smell like popcorn.

    PubMed

    Greene, Lydia K; Wallen, Timothy W; Moresco, Anneke; Goodwin, Thomas E; Drea, Christine M

    2016-06-01

    Members of the order Carnivora rely on urinary scent signaling, particularly for communicating about reproductive parameters. Here, we describe reproductive endocrine patterns in relation to urinary olfactory cues in a vulnerable and relatively unknown viverrid--the binturong (Arctictis binturong). Female binturongs are larger than and dominate males, and both sexes engage in glandular and urinary scent marking. Using a large (n = 33), captive population, we collected serum samples to measure circulating sex steroids via enzyme immunoassay and urine samples to assay volatile chemicals via gas chromatography-mass spectrometry. Male binturongs had expectedly greater androgen concentrations than did females but, more unusually, had equal estrogen concentrations, which may be linked to male deference. Males also expressed a significantly richer array of volatile chemical compounds than did females. A subset of these volatile chemicals resisted decay at ambient temperatures, potentially indicating their importance as long-lasting semiochemicals. Among these compounds was 2-acetyl-1-pyrroline (2-AP), which is typically produced at high temperatures by the Maillard reaction and is likely to be responsible for the binturong's characteristic popcorn aroma. 2-AP, the only compound expressed by all of the subjects, was found in greater abundance in males than females and was significantly and positively related to circulating androstenedione concentrations in both sexes. This unusual compound may have a more significant role in mammalian semiochemistry than previously appreciated. Based on these novel data, we suggest that hormonal action and potentially complex chemical reactions mediate communication of the binturong's signature scent and convey information about sex and reproductive state. PMID:27056047

  5. Volatile compounds and antioxidative activity of Porophyllum tagetoides extracts.

    PubMed

    Jimenez, M; Guzman, A P; Azuara, E; Garcia, O; Mendoza, M R; Beristain, C I

    2012-03-01

    Porophyllum tagetoides is an annual warm-weather herb that has an intense typical smell. Its leaves are commonly used in soup preparation and traditional medicine for treatment of inflammatory diseases. Its volatile compounds and antioxidant properties were evaluated in crude, aqueous and ethanol leaf extract and an oil emulsion using different antioxidant assays in vitro, such as: DPPH radical scavenging activity, redox potential, polyphenol content, reducing power and optical density. A high antioxidative activity was found when comparing leaves with stems. The crude extract from leaves showed a very high reducing power (2.88 ± 0.20 O.D.) and DPPH radical-scavenging activity (54.63 ± 4.80%), in concordance with a major concentration of vitamin C (23.97 ± 0.36 mg/100 g). Instead, the highest polyphenol content (264.54 ± 2.17 mg GAE/g of sample) and redox potential (561.23 ± 0.15 mV) were found by the ethanol and aqueous extract, respectively. Aldehydes and terpenes such as nonanal, decanal, trans-pineno, β-myrcene and D-limonene were the major volatiles found. This study suggests that Porophyllum tagetoides extracts could be used as antioxidants. PMID:22318745

  6. Secondary organic aerosol from biogenic volatile organic compound mixtures

    NASA Astrophysics Data System (ADS)

    Hatfield, Meagan L.; Huff Hartz, Kara E.

    2011-04-01

    The secondary organic aerosol (SOA) yields from the ozonolysis of a Siberian fir needle oil (SFNO), a Canadian fir needle oil (CFNO), and several SOA precursor mixtures containing reactive and non-reactive volatile organic compounds (VOCs) were investigated. The use of precursor mixtures more completely describes the atmosphere where many VOCs exist. The addition of non-reactive VOCs such as bornyl acetate, camphene, and borneol had very little to no effect on SOA yields. The oxidation of VOC mixtures with VOC mass percentages similar to the SFNO produced SOA yields that became more similar to the SOA yield from SFNO as the complexity and concentration of VOCs within the mixture became more similar to overall SFNO composition. The SOA yield produced by the oxidation of CFNO was within the error of the SOA yield produced by the oxidation of SFNO at a similar VOC concentration. The SOA yields from SFNO were modeled using the volatility basis set (VBS), which predicts the SOA yields for a given mass concentration of mixtures containing similar VOCs.

  7. 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. PMID:26697273

  8. 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.

  9. 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.

  10. 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.

  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. 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.

  13. 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

  14. 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.

  15. Ambient ionization and direct identification of volatile organic compounds with microwave-induced plasma mass spectrometry.

    PubMed

    Li, Dandan; Tian, Yong-Hui; Zhao, Zhongjun; Li, Wenwen; Duan, Yixiang

    2015-02-01

    An innovative method of volatile organic compounds analysis by using microwave-induced plasma ionization (MIPI) source in combination with an ambient ion trap mass spectrometer is presented here. Using MIPI for direct sample vapor, analysis was achieved without any sample preparation or subsequent heating. The relative abundance of the target compounds can be obtained almost instantly within a few seconds. The ionization processes of different volatile compounds was optimized, and the limits of detection were identified in the range of 0.15-4.5 pptv or 0.73-8.80 pg ml(-1). The relative standard deviation (RSD) is in the range of 4-14%, while correlation coefficients of the working curves (R(2)) are better than 0.98. The new method possesses advantages of ease operation, time-saving, high sensitivity and inexpensive setup. In addition, the ionization processes of short n-alkane chains were investigated with the MIPI technique, and a unique [M + 13](+) was detected, which has not been reported in detail by any other related ionization techniques. An ionization mechanism was proposed on the basis of the experimental results obtained in this work and available information in literatures, in which the n-alkanes in the plasma environment possibly generate protonated cyclopentadiene [M - 5](+) or alkyl-substituted analogues as well as hydrous ions [M + 13](+) and [M + 13 + 18](+), as shown in Scheme 1 in the main text. PMID:25800021

  16. Sorption of volatile organic compounds on typical carpet fibers.

    PubMed

    Elkilani, A S; Baker, C G J; Al-Shammari, Q H; Bouhamra, W S

    2003-08-01

    Measurements of adsorption isotherms for three volatile organic compounds (VOCs) (toluene, 1,2-dichlorobenzene and 1,1,1-trichloroethane) on polyacrylonitrile carpet fibers over the temperature range 25-45 degrees C were carried out in a thermogravimetric analyzer (TGA). Linear isotherms were observed in all cases with values of the Henry coefficient ranging from 0.063 to 0.941 mm. The results of additional experiments carried out in a simple test chamber containing a single source of VOC showed that the carpet fibers acted as a significant sink causing a prolonged elevation of VOC concentration in the air within the chamber. An unsteady-state model is presented, which adequately described the adsorption and desorption phenomena occurring in the test chamber and yielded realistic values of the adsorption and desorption rate constants. There was good agreement between the equilibrium and kinetic constants obtained in the TGA and test chamber experiments. PMID:12742400

  17. PDMS-coated fiber volatile organic compounds sensors.

    PubMed

    Ning, Xiangping; Yang, Jingyi; Zhao, Chun Liu; Chan, Chi Chiu

    2016-05-01

    The functionality of poly(dimethylsiloxane) (PDMS)-based interferometric fiber sensors for volatile organic compounds (VOCs) detection is investigated and experimentally demonstrated. Two interferometric configurations are considered in this work, namely Fabry-Perot (FP) and Sagnac interferometers (SI). Both sensors are functionalized with a thin layer of VOC-sensitive polymer: PDMS, whose degree of swelling varies as a function of VOC concentrations. This swelling effect will result in an optical path length and birefringence modulation for FP and SI sensors, respectively. In this paper, the two common VOCs, ethanol and 2-propanol, were detected by the proposed sensor and the inverse matrix method was used to differentiate the VOC in gas mixture. PMID:27140369

  18. 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. PMID:23283536

  19. 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.

  20. Imaging subsurface geology and volatile organic compound plumes

    SciTech Connect

    Qualheim, B.J.; Daley, P.F.; Johnson, V.; McPherrin, R.V.; Laguna, G.

    1992-03-01

    Lawrence Livermore National Laboratory (LLNL) (Fig. 1) is in the final stages of the Superfund decisionmaking process for site remediation and restoration. In the process of characterizing the subsurface of the LLNL site, we have developed unique methods of collecting, storing, retrieving, and imaging geologic and chemical data from more than 350 drill holes. The lateral and vertical continuity of subsurface paleostream channels were mapped for the entire LLNL site using geologic descriptions from core samples, cuttings, and interpretations from geophysical logs. A computer-aided design and drafting program, SLICE, written at LLNL, was used to create two-dimensional maps of subsurface sediments, and state-of-the-art software produced three-dimensional images of the volatile organic compound (VOC) plumes using data from water and core fluid analyses.

  1. 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.

  2. 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.

  3. [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. PMID:26717719

  4. 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

  5. Indoor Volatile Organic Compounds and Chemical Sensitivity Reactions

    PubMed Central

    Win-Shwe, Tin-Tin; Arashidani, Keiichi; Kunugita, Naoki

    2013-01-01

    Studies of unexplained symptoms observed in chemically sensitive subjects have increased the awareness of the relationship between neurological and immunological diseases due to exposure to volatile organic compounds (VOCs). However, there is no direct evidence that links exposure to low doses of VOCs and neurological and immunological dysfunction. We review animal model data to clarify the role of VOCs in neuroimmune interactions and discuss our recent studies that show a relationship between chronic exposure of C3H mice to low levels of formaldehyde and the induction of neural and immune dysfunction. We also consider the possible mechanisms by which VOC exposure can induce the symptoms presenting in patients with a multiple chemical sensitivity. PMID:24228055

  6. 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.

  7. Distribution of aroma volatile compounds in tangerine hybrids and proposed inheritance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the desirable combination of sugars and acids, volatile compounds contribute to the essential organoleptic attributes of citrus. This study evaluated the aroma volatiles of 20 tangerine hybrids of the University of Florida breeding program. Volatiles were sampled from hand-squeezed juice by hea...

  8. 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

  9. 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.

  10. 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. PMID:24592162

  11. 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

  12. Profiling of volatile compounds of Phyllostachys pubescens shoots in Taiwan.

    PubMed

    Chung, Min-Jay; Cheng, Sen-Sung; Lin, Chun-Ya; Chang, Shang-Tzen

    2012-10-15

    This study examined the influence of heating temperature and duration on volatile aromatic components of spring and winter Phyllostachys pubescens shoots using SPME. Results from GC-MS analyses revealed that the main constituents in both bamboo shoots at ambient temperature include methoxy-phenyl oxime, followed by n-hexanol and 3Z-hexenal, which gives a fresh green aroma. Comparing the different compounds, between spring and winter shoots, revealed that spring bamboo shoots at ambient temperature comprise 12.30% methyl salicylate, which provides protection against insect attack, and 9.71% epi-cedrol; while winter bamboo shoots comprise 17.00% 1-octen-3-ol, which produces a distinct mushroom aroma. After heating at 100 °C for 60 min, a marked increase in relative content of benzyl salicylate (43.30%) and a significant decrease in methyl salicylate content in spring bamboo shoots were observed; while the major compound in winter bamboo shoots was n-heneicosane (78.09%) and the content of specific 1-octen-3-ol significantly decreased. PMID:23442614

  13. 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. PMID:24689733

  14. 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.

  15. 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.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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)...

  3. 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)...

  4. 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)...

  5. 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)...

  6. 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)...

  7. 78 FR 11101 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of trans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... definition was first set forth in the ``Recommended Policy on Control of Volatile Organic Compounds'' (42 FR... Volatile Organic Compounds in Ozone State Implementation Plans'' (Interim Guidance) (70 FR 54046, September...-reviewed journal articles on its atmospheric chemistry, reaction rates, atmospheric lifetimes and...

  8. 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...

  9. VOLATILE ORGANIC COMPOUND MODEL-QUALITY ASSURANCE AND SENSITIVITY TESTING (VERSION 1.8)

    EPA Science Inventory

    The report describes test runs of the Volatile Organic Compound Model (VOCM), Version 1.8. VOCM predicts future emission levels of volatile organic compounds (VOCs) by projecting uncontrolled base year emissions into the future. These projected emissions are then reduced by const...

  10. Study on photocatalytic degradation of several volatile organic compounds.

    PubMed

    Zuo, Guo-Min; Cheng, Zhen-Xing; Chen, Hong; Li, Guo-Wen; Miao, Ting

    2006-02-01

    The gas-phase photolytic and photocatalytic reactions of several aromatics and chlorohydrocarbons were investigated. The experimental results revealed that chlorohydrocarbons like trichloroethylene, dichloromethane and chloroform could be degraded through either photolysis or photocatalysis under irradiation of germicidal lamp, and the elimination rate of chlorohydrocarbons through photolysis was quicker than that through photocatalysis. UV light from a germicidal lamp could directly lead to degradation of toluene but could hardly act on benzene. The photodegradation rate for these volatile organic compounds (VOCs) through photolysis followed an order: trichloroethylene>chloroform>dichloromethane>toluene>benzene>carbon tetrachloride, and through photocatalysis followed: trichloroethylene>chloroform>toluene>dichloromethane>benzene>carbon tetrachloride. Besides, a series of modified TiO2 photocatalysts were prepared by depositing noble metal, doping with transition metal ion, recombining with metal oxides and modifying with super strong acid. Activity of these catalysts was examined upon photocatalytic degradation of benzene as a typical compound that was hard to be degraded. It indicated that these modification methods could promote the activity of TiO2 catalyst to different extent. The apparent zero-order reaction rate constant for degrading benzene over SnO2/TiO2 catalyst had the highest value, which was nearly three times as that over P25 TiO2. But it simultaneously had the lowest rate for mineralizing the objective compound. In spite that Fe3+/TiO2 catalyst behaved slightly less active than SnO2/TiO2 for degradation of benzene, the mineralization rate over Fe3+/TiO2 was the highest one among the prepared catalysts. PMID:16157448

  11. 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. PMID:16878585

  12. 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

  13. Volatile organic compounds in an urban airborne environment adjacent to a municipal incinerator, waste collection centre and sewage treatment plant

    NASA Astrophysics Data System (ADS)

    Leach, J.; Blanch, A.; Bianchi, A. C.

    The occurrence and temporal distribution of airborne volatile organic compounds (VOC) at nine closely grouped locations in a suburban environment on the edge of the coastline of the Southampton Water estuary, located on the coastline of central southern England, was studied over six monthly periods spanning 1996-1997. The sampling sites circumscribed a juxtaposed municipal incinerator, waste collection and processing centre and sewage treatment plant. Three sets of airborne samples being taken before and after the closure of the municipal incinerator. VOC with volatilities of low to medium polarity ranging broadly from those of n-butane to n-octadecane were the major focus of interest. Over 100 individual compounds were routinely found in localised samples taken during the period of study. The types and concentrations of VOC identified partly reflect the imprint of the various waste processing operations on atmospheric VOC within the local environment. The most abundant VOC classes consisted of aromatic, chlorinated and organosulphide compounds, with smaller proportions of alkanes, alkenes and cycloalkane compounds. Compounds produced by sewage-processing and waste management operations, including volatile organosulphides and various oxygenated compounds, may occasionally exceed olfactory detection thresholds and represent a source of potential odour complaints in the local urban environment.

  14. Effect of pork fat addition on the volatile compounds of foal dry-cured sausage.

    PubMed

    Lorenzo, José M; Montes, Rosa; Purriños, Laura; Franco, Daniel

    2012-08-01

    The effect of fat content on volatile compounds from foal dry-cured sausage was studied. Three batches (10 units per batch) of dry fermented sausages with different pork back fat content (5%, 10% and 20%) were manufactured; low fat (LF), medium fat (MF) and high fat (HF), respectively. A total of 45 volatile compounds were extracted by purge-and-trap and identified by GC-MS in the headspace of the batches. The mixture comprised 11 terpenes, 15 esters, 14 hydrocarbons and 2 alcohols. Spices were responsible for the generation of 14 volatile compounds comprising terpenes and hydrocarbons. After 49 days of ripening volatile compounds from spices represented 52.9, 38.9 and 31.2% of the total area for samples from LF, MF and HF batches, respectively, while lipid autooxidation was responsible for the generation of 8 volatile compounds. The PCA offered a good separation of the mean samples according to their fat content. PMID:22498135

  15. Compositing water samples for analysis of volatile organic compounds

    USGS Publications Warehouse

    Lopes, T.J.; Fallon, J.D.; Maluk, T.L.

    2000-01-01

    Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Researchers are able to derive

  16. 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

  17. Performance audits and laboratory comparisons for SCOS97-NARSTO measurements of speciated volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Fujita, Eric M.; Harshfield, Gregory; Sheetz, Laurence

    Performance audits and laboratory comparisons were conducted as part of the quality assurance program for the 1997 Southern California Ozone Study (SCOS97-NARSTO) to document potential measurement biases among laboratories measuring speciated nonmethane hydrocarbons (NMHC), carbonyl compounds, halogenated compounds, and biogenic hydrocarbons. The results show that measurements of volatile organic compounds (VOC) made during SCOS97-NARSTO are generally consistent with specified data quality objectives. The hydrocarbon comparison involved nine laboratories and consisted of two sets of collocated ambient samples. The coefficients of variation among laboratories for the sum of the 55 PAM target compounds and total NMHC ranged from ±5 to 15 percent for ambient samples from Los Angeles and Azusa. Abundant hydrocarbons are consistently identified by all laboratories, but discrepancies occur for olefins greater than C 4 and for hydrocarbons greater than C 8. Laboratory comparisons for halogenated compounds and biogenic hydrocarbons consisted of both concurrent ambient sampling by different laboratories and round-robin analysis of ambient samples. The coefficients of variation among participating laboratories were about 10-20 percent. Performance audits were conducted for measurement of carbonyl compounds involving sampling from a standard mixture of carbonyl compounds. The values reported by most of the laboratories were within 10-20 percent of those of the reference laboratory. Results of field measurement comparisons showed larger variations among the laboratories ranging from 20 to 40 percent for C 1-C 3 carbonyl compounds. The greater variations observed in the field measurement comparison may reflect potential sampling artifacts, which the performance audits did not address.

  18. Volatile Compound-Mediated Interactions between Barley and Pathogenic Fungi in the Soil

    PubMed Central

    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. PMID:23818966

  19. Large drought-induced variations in oak leaf volatile organic compound emissions during PINOT NOIR 2012

    DOE PAGESBeta

    Geron, Chris; Gu, Lianhong; Daly, Ryan; Harley, Peter; Rasmussen, Rei; Seco, Roger; Guenther, Alex; Karl, Thomas

    2015-12-17

    Here, leaf-level isoprene and monoterpene emissions were collected and analyzed from five of the most abundant oak (Quercus) species in Central Missouri's Ozarks Region in 2012 during PINOT NOIR (Particle Investigations at a Northern Ozarks Tower – NOx, Oxidants, Isoprene Research). June measurements, prior to the onset of severe drought, showed isoprene emission rates and leaf temperature responses similar to those previously reported in the literature and used in Biogenic Volatile Organic Compound (BVOC) emission models. During the peak of the drought in August, isoprene emission rates were substantially reduced, and response to temperature was dramatically altered, especially for themore » species in the red oak subgenus (Erythrobalanus).« less

  20. Effect of cooking on physicochemical properties and volatile compounds in lotus root (Nelumbo nucifera Gaertn).

    PubMed

    Li, Shuyi; Li, Xiaojin; Lamikanra, Olusola; Luo, Qing; Liu, Zhiwei; Yang, Jun

    2017-02-01

    The effects of boiling and steaming on lotus root volatile compounds and some of its physicochemical properties were determined. A total of 52 compounds identified in the raw tuber by GC-MS were a combination of the rhizome's native compounds and those from the soil and water environment, and are predominantly a mixture of straight chain and cyclic alkanes, and aromatic hydrocarbons. Boiling increased concentrations of most of these compounds, unlike steaming that lowered total volatile components of the tuber. Cooking increased complexity of volatile compounds with the production of new compounds such as methylated derivatives, particularly in steam cooked lotus. Other heat-induced compounds include antioxidants such as butylated hydroxyl compounds and antifungal organic compounds such as dimethyl disulfide. Instrumental texture measurements indicate that the characteristic post-cooked retention of crunchiness in lotus root is likely to be related to retention of its springiness index through the cooking process. PMID:27596426

  1. A global model of natural volatile organic compound emissions

    NASA Astrophysics Data System (ADS)

    Guenther, Alex; Hewitt, C. Nicholas; Erickson, David; Fall, Ray; Geron, Chris; Graedel, Tom; Harley, Peter; Klinger, Lee; Lerdau, Manuel; McKay, W. A.; Pierce, Tom; Scholes, Bob; Steinbrecher, Rainer; Tallamraju, Raja; Taylor, John; Zimmerman, Pat

    1995-05-01

    Numerical assessments of global air quality and potential changes in atmospheric chemical constituents require estimates of the surface fluxes of a variety of trace gas species. We have developed a global model to estimate emissions of volatile organic compounds from natural sources (NVOC). Methane is not considered here and has been reviewed in detail elsewhere. The model has a highly resolved spatial grid (0.5°×0.5° latitude/longitude) and generates hourly average emission estimates. Chemical species are grouped into four categories: isoprene, monoterpenes, other reactive VOC (ORVOC), and other VOC (OVOC). NVOC emissions from oceans are estimated as a function of geophysical variables from a general circulation model and ocean color satellite data. Emissions from plant foliage are estimated from ecosystem specific biomass and emission factors and algorithms describing light and temperature dependence of NVOC emissions. Foliar density estimates are based on climatic variables and satellite data. Temporal variations in the model are driven by monthly estimates of biomass and temperature and hourly light estimates. The annual global VOC flux is estimated to be 1150 Tg C, composed of 44% isoprene, 11% monoterpenes, 22.5% other reactive VOC, and 22.5% other VOC. Large uncertainties exist for each of these estimates and particularly for compounds other than isoprene and monoterpenes. Tropical woodlands (rain forest, seasonal, drought-deciduous, and savanna) contribute about half of all global natural VOC emissions. Croplands, shrublands and other woodlands contribute 10-20% apiece. Isoprene emissions calculated for temperate regions are as much as a factor of 5 higher than previous estimates.

  2. 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

  3. A biogenic volatile organic compounds emission inventory for Yunnan Province.

    PubMed

    Wang, Zhi-Hui; Bai, Yu-Hua; Zhang, Shu-Yu

    2005-01-01

    The first detailed inventory for volatile organic compounds (VOC) emissions from vegetation over Yunnan Province, China was presented. The spatially and temporally resolved inventory was developed based on a geographic information system (GIS), remote sensing (RS) data and field measurement data, such as digitized land-use data, normalized difference vegetation index (NDVI) and temperature data from direct real-time measurement. The inventory has a spatial resolution of 5 km x 5 km and a time resolution of 1 h. Urban, agriculture, and natural land-use distributions in Yunnan Province were combined with biomass factors for each land-use category to produce a spatially resolved biomass inventory. A biogenic emission inventory was developed by combining the biomass inventory with hourly emission rates for tree, shrub and ground cover species of the study area. Correcting for environmental factors, including light intensity and temperature, a value of 1.1 x 10(12) gC for total annual biogenic VOC emissions from Yunnan Province, including 6.1 x 10(11) gC for isoprene, 2.1 x 10(11) gC for monoterpenes, and 2.6 x 10(11) gC for OVOC was obtained. The highest VOC emissions occurred in the northwestern, southwestern and north region of Yunnan Province. Some uncertainties were also discussed in this study. PMID:16083102

  4. 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.

  5. 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.

  6. Evaluation of volatile organic compound reduction technologies for metal coatings

    SciTech Connect

    Wang, Y.; Huang, E.W.

    1997-12-31

    Under the sponsorship of California Air Resources Board, AeroVironment Environmental Services, Inc. (AVES) is currently conducting a study to demonstrate a new zero-VOC Industrial Maintenance Metal Coating. This new technology can help the coating industry reduce emissions of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs). In a previous study conducted by AVES, current VOCs technologies available on the market for metal parts and product coatings were evaluated for compliance with the South Coast Air Quality Management District (SCAQMD) proposed Rule 1107 (Metal Parts and Product Coatings). There are low-VOC coating products available for industries of interest. For general metal coating applications, certain coating products can comply with current SCAQMD Rule 1107 VOC limits. Some of the low-VOC products that are considered as a substitute or an alternative to high-VOC petroleum-based products are summarized. The current available emerging technologies offer a great opportunity for emission reduction through a gradual shift from high to low/no VOC coatings. By phasing in low/no VOC coatings, industries will be able to reduce energy use and air emissions without installation of add-on controls.

  7. Elimination of volatile organic compounds by biofiltration: a review.

    PubMed

    Nikiema, Josiane; Dastous, Paul-André; Heitz, Michèle

    2007-01-01

    Volatile organic compounds (VOCs) are pollutants that are responsible for the formation of the tropospheric ozone, one of the precursors of smog. VOCs are emitted by various industries including chemical plants, pulp and paper mills, pharmaceuticals, cosmetics, electronics and agri-food industries. Some VOCs cause odor pollution while many of them are harmful to environment and human or animal health. For the removal of VOCs, biofiltration, a biological process, has proved to be reliable when properly operated. This process has therefore been widely applied in Europe and North America. The main advantages associated with the use of biofiltration are related to its set-up, maintenance, and operating costs which are usually lower than those related to other VOCs control technologies and because it is less harmful for the environment than conventional processes like incineration. In the present paper, the main parameters (type, moisture, pH, and temperature of filter bed, microbial population, nutrients concentrations, and VOCs' inlet load) to be controlled during the biofiltration are identified and described in detail. The main phenomena involved in biofiltration are also discussed. For improving the efficiency of VOC control biotechnology, new techniques are now proposed that include the use of membranes, biphasic reactors, UV photolysis, and many others. PMID:18351227

  8. Sources of volatile organic compounds in Cairo's ambient air.

    PubMed

    Abu-Allaban, M; Lowenthal, D H; Gertler, A W; Labib, M

    2009-10-01

    The greater Cairo area suffers from extreme levels of gas and particulate phase air pollutants. In order to reduce the levels of ambient pollution, the USAID and the Egyptian Environmental Affairs Agency (EEAA) have supported the Cairo Air Improvement Project (CAIP). As part of this project, two intensive ambient monitoring studies were carried out during the period of February 22 to March 4 and October 27 to November 27, 1999. Volatile organic compounds (VOCs) were measured on a 24-h basis at six sampling stations during each of the intensive periods. During the February/March study, samples were collected daily, while in the October/November study samples were collected every other day. The six intensive measurement sites represented background levels, mobile source impacts, industrial impacts, and residential exposure. High levels of NMHC were observed at all locations. NMHC concentrations ranged from 365 ppb C at Helwan to 1,848 ppb C at El Qualaly during winter, 1999 and from 461 ppb C at Kaha to 2,037 ppb C at El Qualaly during fall, 1999. El Qualaly, the site chosen to represent mobile emissions, displayed the highest average NMHC concentrations of any site, by a factor of 2 or more. The highest mobile source contributions were estimated at this site. The major contributors to NMHC at all sites were mobile emissions, lead smelting, and compressed natural gas. PMID:18843549

  9. 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. PMID:25788118

  10. 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.

  11. 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.

  12. 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. PMID:19029718

  13. 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. PMID:26271945

  14. 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.

  15. 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.

  16. 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).

  17. 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

  18. 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.

  19. Influence of Sensory Stimulation on Exhaled Volatile Organic Compounds.

    PubMed

    Mazzatenta, A; Pokorski, M; Di Tano, A; Cacchio, M; Di Giulio, C

    2016-01-01

    The real-time exhaled volatile organic compounds (VOCs) have been suggested as a new biomarker to detect and monitor physiological processes in the respiratory system. The VOCs profile in exhaled breath reflects the biochemical alterations related to metabolic changes, organ failure, and neuronal activity, which are, at least in part, transmitted via the lungs to the alveolar exhaled breath. Breath analysis has been applied to investigate cancer, lung failure, and neurodegenerative diseases. There are by far no studies on the real-time monitoring of VOCs in sensory stimulation in healthy subjects. Therefore, in this study we investigated the breath parameters and exhaled VOCs in humans during sensory stimulation: smell, hearing, sight, and touch. Responses sensory stimulations were recorded in 12 volunteers using an iAQ-2000 sensor. We found significant effects of sensory stimulation. In particular, olfactory stimulation was the most effective stimulus that elicited the greatest VOCs variations in the exhaled breath. Since the olfactory pathway is distinctly driven by the hypothalamic and limbic circuitry, while other senses project first to the thalamic area and then re-project to other brain areas, the findings suggest the importance of olfaction and chemoreception in the regulation lung gas exchange. VOCs variations during sensory activation may become putative indicators of neural activity. PMID:26453064

  20. Advanced heat pump for the recovery of volatile organic compounds

    SciTech Connect

    Not Available

    1992-03-01

    Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total US VOC emissions. The Toxic-Release Inventory'' of The US 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 US 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 I 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. 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.

  1. 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.

  2. [Volatile organic compounds (VOCs) emitted from furniture and electrical appliances].

    PubMed

    Tanaka-Kagawa, Toshiko; Jinno, Hideto; Furukawa, Yoko; Nishimura, Tetsuji

    2010-01-01

    Organic chemicals are widely used as ingredients in household products. Therefore, furniture and other household products as well as building products may influence the indoor air quality. This study was performed to estimate quantitatively influence of household products on indoor air quality. Volatile organic compound (VOC) emissions were investigated for 10 products including furniture (chest, desk, dining table, sofa, cupboard) and electrical appliances (refrigerator, electric heater, desktop personal computer, liquid crystal display television and audio) by the large chamber test method (JIS A 1912) under the standard conditions of 28 degrees C, 50% relative humidity and 0.5 times/h ventilation. Emission rate of total VOC (TVOC) from the sofa showed the highest; over 7900 microg toluene-equivalent/unit/h. Relatively high TVOC emissions were observed also from desk and chest. Based on the emission rates, the impacts on the indoor TVOC were estimated by the simple model with a volume of 17.4 m3 and ventilation frequency of 0.5 times/h. The estimated TVOC increment for the sofa was 911 microg/m3, accounting for almost 230% of the provisional target value, 400 microg/m3. The values of estimated increment of toluene emitted from cupboard and styrene emitted from refrigerator were 10% and 16% of guideline values, respectively. These results revealed that VOC emissions from household products may influence significantly indoor air quality. PMID:21381398

  3. Abundance of He-3 and other solar-wind-derived volatiles in lunar soil

    NASA Astrophysics Data System (ADS)

    Swindle, Timothy D.

    Volatiles implanted into the lunar regolith by the solar wind are potentially important lunar resources. Wittenberg et al. (1986) have proposed that lunar He-3 could be used as a fuel for terrestrial nuclear fusion reactors. They argue that a fusion scheme involving D and He-3 would be cleaner and more efficient than currently-proposed schemes involving D and T. However, since the terrestrial inventory of He-3 is so small, they suggest that the lunar regolith, with concentrations of the order of parts per billion (by mass) would be an economical source of He-3. Solar-wind implantation is also the primary source of H, C, and N in lunar soil. These elements could also be important, particularly for life support and for propellant production. In a SERC study of the feasibility of obtaining the necessary amount of He-3, Swindle et al. (1990) concluded that the available amount is sufficient for early reactors, at least, but that the mining problems, while not necessarily insurmountable, are prodigious. The volatiles H, C, and N, on the other hand, come in parts per million level abundances. The differences in abundances mean that (1) a comparable amount of H, C, and/or N could be extracted with orders of magnitude smaller operations than required for He-3, and (2) if He-3 extraction ever becomes important, huge quantities of H, C, and N will be produced as by-products.

  4. Abundance of He-3 and other solar-wind-derived volatiles in lunar soil

    NASA Technical Reports Server (NTRS)

    Swindle, Timothy D.

    1992-01-01

    Volatiles implanted into the lunar regolith by the solar wind are potentially important lunar resources. Wittenberg et al. (1986) have proposed that lunar He-3 could be used as a fuel for terrestrial nuclear fusion reactors. They argue that a fusion scheme involving D and He-3 would be cleaner and more efficient than currently-proposed schemes involving D and T. However, since the terrestrial inventory of He-3 is so small, they suggest that the lunar regolith, with concentrations of the order of parts per billion (by mass) would be an economical source of He-3. Solar-wind implantation is also the primary source of H, C, and N in lunar soil. These elements could also be important, particularly for life support and for propellant production. In a SERC study of the feasibility of obtaining the necessary amount of He-3, Swindle et al. (1990) concluded that the available amount is sufficient for early reactors, at least, but that the mining problems, while not necessarily insurmountable, are prodigious. The volatiles H, C, and N, on the other hand, come in parts per million level abundances. The differences in abundances mean that (1) a comparable amount of H, C, and/or N could be extracted with orders of magnitude smaller operations than required for He-3, and (2) if He-3 extraction ever becomes important, huge quantities of H, C, and N will be produced as by-products.

  5. Volatile Organic Compounds Emissions from Luculia pinceana Flower and Its Changes at Different Stages of Flower Development.

    PubMed

    Li, Yuying; Ma, Hong; Wan, Youming; Li, Taiqiang; Liu, Xiuxian; Sun, Zhenghai; Li, Zhenghong

    2016-01-01

    Luculia plants are famed ornamental plants with sweetly fragrant flowers, of which L. pinceana Hooker, found primarily in Yunnan Province, China, has the widest distribution. Solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was employed to identify the volatile organic compounds (VOCs) emitted from different flower development stages of L. pinceana for the evaluation of floral volatile polymorphism. Peak areas were normalized as percentages and used to determine the relative amounts of the volatiles. The results showed that a total of 39 compounds were identified at four different stages of L. pinceana flower development, including 26 at the bud stage, 26 at the initial-flowering stage, 32 at the full-flowering stage, and 32 at the end-flowering stage. The most abundant compound was paeonol (51%-83%) followed by (E,E)-α-farnesene, cyclosativene, and δ-cadinene. All these volatile compounds create the unique fragrance of L. pinceana flower. Floral scent emission offered tendency of ascending first and descending in succession, meeting its peak level at the initial-flowering stage. The richest diversity of floral volatile was detected at the third and later periods of flower development. Principal component analysis (PCA) indicated that the composition and its relative content of floral scent differed throughout the whole flower development. The result has important implications for future floral fragrance breeding of Luculia. L. pinceana would be adequate for a beneficial houseplant and has a promising prospect for development as essential oil besides for a fragrant ornamental owing to the main compounds of floral scent with many medicinal properties. PMID:27110758

  6. Changes in volatile compounds and some physicochemical properties of European cranberrybush (Viburnum opulus L.) during ripening through traditional fermentation.

    PubMed

    Yilmaztekin, Murat; Sislioglu, Kubra

    2015-04-01

    The changes in volatile compounds and some physicochemical properties of European Cranberrybush (Viburnum opulus L.) were investigated during traditional fermentation. Using the principal component analysis (PCA), relations between volatile compounds and fermentation were associated with dynamics of these compounds. In total, 58 volatile compounds were identified, 3-methylbutanoic acid (25.4% to 66.4% of identified volatile compounds) being the major constituent in raw, 2-, 3-, and 4-mo fermented European Cranberrybush fruits, while 2-octanone was dominant in 1-mo fermented sample with a 30% of the total identified volatiles. The amount of total volatile compounds was increased in the 1st month of fermentation and then decreased gradually in the following months. Acids were the dominant volatile compounds in raw and 3- to 4-mo fermented European Cranberrybush. Ketones and alcohols had the highest percentage in total volatile compounds in the 2nd and 3rd months of fermentation, respectively. PMID:25808206

  7. Soil sampling and analysis for volatile organic compounds.

    PubMed

    Lewis, T E; Crockett, A B; Siegrist, R L

    1994-05-01

    Concerns over data quality have raised many questions related to sampling soils for volatile organic compounds (VOCs). This paper was prepared in response to some of these questions and concerns expressed by Remedial Project Managers (RPMs) and On-Scene Coordinators (OSCs). The following questions are frequently asked: 1. Is there a specific device suggested for sampling soils for VOCs? 2. Are there significant losses of VOCs when transferring a soil sample from a sampling device (e.g., split spoon) into the sample container? 3. What is the best method for getting the sample from the split spoon (or other device) into the sample container? 4. Are there smaller devices such as subcore samplers available for collecting aliquots from the larger core and efficiently transferring the sample into the sample container? 5. Are certain containers better than others for shipping and storing soil samples for VOC analysis? 6. Are there any reliable preservation procedures for reducing VOC losses from soil samples and for extending holding times? Guidance is provided for selecting the most effective sampling device for collecting samples from soil matrices. The techniques for sample collection, sample handling, containerizing, shipment, and storage described in this paper reduce VOC losses and generally provide more representative samples for volatile organic analyses (VOA) than techniques in current use. For a discussion on the proper use of sampling equipment the reader should refer to other sources (Acker, 1974; U.S. EPA, 1983; U.S. EPA, 1986a).Soil, as referred to in this report, encompasses the mass (surface and subsurface) of unconsolidated mantle of weathered rock and loose material lying above solid rock. Further, a distinction must be made as to what fraction of the unconsolidated material is soil and what fraction is not. The soil component here is defined as all mineral and naturally occurring organic material that is 2 mm or less in size. This is the size normally

  8. Exchange of volatile organic compounds in the boreal forest floor

    NASA Astrophysics Data System (ADS)

    Aaltonen, Hermanni; Bäck, Jaana; Pumpanen, Jukka; Pihlatie, Mari; Hakola, Hannele; Hellén, Heidi; Aalto, Juho; Heinonsalo, Jussi; Kajos, Maija K.; Kolari, Pasi; Taipale, Risto; Vesala, Timo

    2013-04-01

    Terrestrial ecosystems, mainly plants, emit large amounts of volatile organic compounds (VOCs) into the atmosphere. In addition to plants, VOCs also have less-known sources, such as soil. VOCs are a very diverse group of reactive compounds, including terpenoids, alcohols, aldehydes and ketones. Due to their high reactivity, VOCs take part in formation and growth of secondary organic aerosols in the atmosphere and thus affect also Earth's radiation balance (Kulmala et al. 2004). We have studied boreal soil and forest floor VOC fluxes with chamber and snow gradient techniques we were developed. Spatial and temporal variability in VOC fluxes was studied with year-round measurements in the field and the sources of boreal soil VOCs in the laboratory with fungal isolates. Determination of the compounds was performed mass spectrometrically. Our results reveal that VOCs from soil are mainly emitted by living roots, above- and belowground litter and microbes. The strongest source appears to be litter, in which both plant residuals and decomposers play a role in the emissions. Soil fungi showed high emissions of lighter VOCs, like acetone, acetaldehyde and methanol, from isolates. Temperature and moisture are the most critical physical factors driving VOC fluxes. Since the environment in boreal forests undergoes strong seasonal changes, the VOC flux strength of the forest floor varies markedly during the year, being highest in spring and autumn. The high spatial heterogeneity of the forest floor was also clearly visible in VOC fluxes. The fluxes of other trace gases (CO2, CH4 and N2O) from soil, which are also related to the soil biological activity and physical conditions, did not show correlations with the VOC fluxes. These results indicate that emissions of VOCs from the boreal forest floor account for as much as several tens of percent, depending on the season, of the total forest ecosystem VOC emissions. This emphasises that forest floor compartment should be taken into

  9. Exposure to volatile organic compounds: Comparison among different transportation modes

    NASA Astrophysics Data System (ADS)

    Do, Duc Hoai; Van Langenhove, Herman; Chigbo, Stephen Izuchukwu; Amare, Abebech Nuguse; Demeestere, Kristof; Walgraeve, Christophe

    2014-09-01

    The increasing trend of promoting public transportation (bus tram, metro, train) and more environmental friendly and sustainable non fossil-fuel alternatives (walking, cycling etc) as substitutes for auto vehicles brings forward new questions with regard to pollutant levels to which commuters are exposed. In this study, three transportation modes (tram, auto vehicle and bicycle) are studied and concentration levels of 84 volatile organic compounds (VOCs) (hydrocarbons, aromatic hydrocarbons, oxygen containing hydrocarbons, terpenes and halogenated compounds) are measured along a route in the city of Ghent, Belgium. The concentration levels are obtained by active sampling on Tenax TA sorbent tubes followed by thermal desorption gas chromatography mass spectrometry (TD-GC-MS) using deuterated toluene as an internal standard. The median total VOC concentrations for the tram mode (33 μg/m³) is 1.7 times higher than that of the bicycle mode (20 μg/m³) and 1.5 times higher than for the car mode (22 μg/m³). It is found that aromatic hydrocarbons account for a significant proportion in the total VOCs concentration (TVOCs) being as high as 41-57%, 59-72% and 58-72% for the tram, car and bicycle respectively. In all transportation modes, there was a high (r > 0.6) degree of correlation between BTEX compounds, isopropylbenzene, n-propylbenzene, 1,3,5-trimethylbenzene and 1,2,4-trimethylbenzene. When comparing time weighed average concentrations along a fixed route in Ghent, it is found that commuters using the tram mode experience the highest TVOCs concentration levels. However, next to the concentration level to which commuters are exposed, the physical activity level involving the mode of transportation is important to assess the exposure to toxic VOCs. It is proven that the commuter using a bicycle (4.3 ± 1.5 μg) inhales seven and nine times more benzene compared to the commuter using the car and tram respectively, when the same route is followed.

  10. Analysis of volatile flavour compounds and acrylamide in roasted Malaysian tropical almond (Terminalia catappa) nuts using supercritical fluid extraction.

    PubMed

    Lasekan, Ola; Abbas, Kassim

    2010-01-01

    Considering the importance of tropical almond nuts as a snack item, a study was conducted to identify the flavour volatiles and acrylamide generated during the roasting of the nuts. The supercritical fluid extracted flavour components revealed 74 aroma active compounds made up of 27 hydrocarbons, 12 aldehydes, 11 ketones, 7 acids, 4 esters, 3 alcohols, 5 furan derivatives a pyrazine, and 2 unknown compounds. While low levels of acrylamide (8-86 microg/kg) were obtained in the roasted nuts, significant (P<0.05) increases occurred in concentration with increased roasting temperature and time. Carboxylic acids were the most abundant volatiles in the roasted almond nuts and less significant (P>0.05) concentration of acrylamide was generated with mild roasting and shorter roasting period. PMID:20510332

  11. Novel Set-Up for Low-Disturbance Sampling of Volatile and Non-volatile Compounds from Plant Roots.

    PubMed

    Eilers, Elisabeth J; Pauls, Gerhard; Rillig, Matthias C; Hansson, Bill S; Hilker, Monika; Reinecke, Andreas

    2015-03-01

    Most studies on rhizosphere chemicals are carried out in substrate-free set-ups or in artificial substrates using sampling methods that require an air flow and may thus cause disturbance to the rhizosphere. Our study aimed to develop a simplified and inexpensive system that allows analysis of rhizosphere chemicals at experimentally less disturbed conditions. We designed a mesocosm in which volatile rhizosphere chemicals were sampled passively (by diffusion) without air- and water flow on polydimethylsiloxane-(PDMS) tubes. Dandelion (Taraxacum sect. ruderalia) was used as model plant; roots were left undamaged. Fifteen volatiles were retrieved from the sorptive material by thermal desorption for analysis by gas chromatography/mass spectrometry (GC/MS). Furthermore, three sugars were collected from the rhizosphere substrate by aqueous extraction and derivatized prior to GC/MS analysis. In order to study how the quantity of detected rhizosphere compounds depends on the type of soil or substrate, we determined the matrix-dependent recovery of synthetic rhizosphere chemicals. Furthermore, we compared sorption of volatiles on PDMS tubes with and without direct contact to the substrate. The results show that the newly designed mesocosm is suitable for low-invasive extraction of volatile and non-volatile compounds from rhizospheres. We further highlight how strongly the type of substrate and contact of PDMS tubes to the substrate affect the detectability of compounds from rhizospheres. PMID:25795090

  12. 40 CFR Table 1 to Subpart D of... - Volatile Organic Compound (VOC), Content Limits for Architectural Coatings

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Volatile Organic Compound (VOC... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards...

  13. 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

  14. Source apportionment of ambient volatile organic compounds in Hong Kong.

    PubMed

    Lau, Alexis Kai Hon; Yuan, Zibing; Yu, Jian Zhen; Louie, Peter K K

    2010-09-01

    Volatile organic compounds (VOCs) were measured at four stations with different environments in Hong Kong (HK) during two sampling campaigns. Positive matrix factorization was applied to characterize major VOC sources in HK. Nine sources were identified, and the spatial and seasonal variations of their contributions were derived. The most significant local VOC sources are vehicle and marine vessel exhausts or liquefied petroleum gas (LPG) at different stations. Vehicle- and marine vessel-related sources accounted for 2.9-12.7ppbv in 2002-2003 and increased to 4.3-15.2ppbv in 2006-2007. Different from the emission inventory, solvent-related sources only contributed 11- 19% at both sampling campaigns. Therefore, emission control from transport sector should be prioritized to alleviate ambient local VOC levels. Additionally, the contribution of aged VOC, which roughly represents contributions from regional and super-regional transport, also showed moderate increase during the four years, indicating cooperation with environmental authorities in the Pearl River Delta and beyond should be strengthened. All the anthropogenic sources contribute most to Yuen Long and least to Tap Mun. However, Tap Mun exhibited different trends in comparison with the other three stations, especially for sources of vehicle and marine vessel exhausts, LPG and paint solvents. When the local source contributions were incorporated with wind data to derive the directional dependences of sources, we may conclude that the rapid development of Yantian Container Terminal, the associated emissions from marine vessels around the Terminal and the on-site activities were likely responsible for the distinct VOC features at Tap Mun. The current impact from the Terminal is mainly concentrated in the northeastern corner of HK; however, it has the potential threat to other locations if the Terminal continues to expand in such a rapid speed in the coming years. More stringent VOC control measures on activities

  15. Volatile Organic Compounds in the Global Atmosphere (Invited)

    NASA Astrophysics Data System (ADS)

    Helmig, D.; Bottenheim, J. W.; Galbally, I.; Lewis, A. C.; Masarie, K.; Milton, M.; Penkett, S.; Plass-Duelmer, C.; Reimann, S.; Steinbrecher, R.; Tans, P. P.; Thiel, S.

    2010-12-01

    The World Meteorological Organization (WMO) - Global Atmospheric Watch (GAW) has been guiding the implementation of a global program for the monitoring of atmospheric volatile organic compounds (VOC). Essential features are 1. regular, in-situ, high temporal resolution measurements of VOC at surface stations, 2. VOC analyses in samples collected within flask sampling networks for wide geographical coverage, and 3. a concerted calibration and data quality control effort. A centerpiece of the flask sampling component builds upon the US NOAA Earth System Research Laboratory - Global Cooperative Air Sampling Network. Nine non-methane hydrocarbon species (NMHC; ethane, propane, iso-butane, n-butane, iso-pentane, n-pentane, isoprene, benzene, toluene) are currently analyzed by an automated gas chromatography system at the University of Colorado’s Institute of Arctic and Alpine Research (INSTAAR) in pairs of samples collected bi-weekly at 41 global background monitoring sites. Since the implementation of this program in 2004 more than 7000 measurements have been obtained. The obtained data allow elucidating the geographical and seasonal behavior of atmospheric NMHC, as well as interannual variations. Results show a wide dynamic range of mixing ratio changes. Concentration maxima and seasonal cycles are most pronounced in regions of highest emission sources and highest changes in the seasonal OH radical sink, i.e. the northern high and mid-latitudes. Seasonal southern hemisphere (SH) maxima are ~7 times and ~20 times lower for ethane and propane than in the northern hemisphere, which mainly reflects the smaller source strength of these gases in the SH. The richness of information in these data will help constraining the variability in global atmospheric oxidation chemistry and regional budgets of greenhouse gases, such as of methane and CO2, and most certainly stimulate further interests and applications in many fields of atmospheric chemistry and climate research

  16. Sources of Volatile Organic Compounds (VOCs) in the UAE

    NASA Astrophysics Data System (ADS)

    Abbasi, Naveed; Majeed, Tariq; Iqbal, Mazhar; Riemer, Daniel; Apel, Eric; Lootah, Nadia

    The gas chromatography-flame ionization detection/mass spectrometry system has been used to identify major volatile organic compounds (VOCs) sources in the UAE (latitude 24.45N; longitude 54.22E). VOCs are emitted from an extensive number of sources in urban environments including fuel production, distribution, and consumption. Transport sources contribute a substantial portion of the VOC burden to the urban atmosphere in developed regions. UAE is located at the edge of the Persian Gulf and is highly affected by emissions from petrochemical industries in neighbouring Saudi Arabia, Qatar, and Iran. VOCs emerging from these industries can be transported to the UAE with jet streams. The analysis of the collected air samples at three locations in Sharjah, UAE during the autumn and winter seasons indicates the presence of more than 100 VOC species. The concentrations of these species vary in magnitudes but the most prominent are: acetylene, ethane, propane, butane, pentane, benzene, and toluene. The possible tracers for various emission sources have also been identified such as 2-methylpentane, 1, 3-butadiene and 2, 2-dimethlybutane for vehicle exhaust, the light hydrocarbons, namely n-butane, trans-2-butene, and n-pentane for gasoline vapor, and n-nonane, n-decane, and n-undecane for diesel vapor and asphalt application processes. As various emission sources are characterized by overlapping VOC species, the ratio of possible VOC tracers are used to quantify the contribution of different sources. Our aim in this paper is to explore and discuss possible impacts of transported emissions on the local VOC emission inventory from various sources for the UAE. This work is partially supported by Office of Development and Alumni Affairs at the American University of Sharjah, U.A.E.

  17. Measuring concentrations of volatile organic compounds in vinyl flooring.

    PubMed

    Cox, S S; Little, J C; Hodgson, A T

    2001-08-01

    The initial solid-phase concentration of volatile organic compounds (VOCs) is a key parameter influencing the emission characteristics of many indoor materials. Solid-phase measurements are typically made using solvent extraction or thermal headspace analysis. The high temperatures and chemical solvents associated with these methods can modify the physical structure of polymeric materials and, consequently, affect mass transfer characteristics. To measure solid-phase concentrations under conditions resembling those in which the material would be installed in an indoor environment, a new technique was developed for measuring VOC concentrations in vinyl flooring (VF) and similar materials. A 0.09-m2 section of new VF was punched randomly to produce -200 0.78-cm2 disks. The disks were milled to a powder at -140 degrees C to simultaneously homogenize the material and reduce the diffusion path length without loss of VOCs. VOCs were extracted from the VF particles at room temperature by fluidized-bed desorption (FBD) and by direct thermal desorption (DTD) at elevated temperatures. The VOCs in the extraction gas from FBD and DTD were collected on sorbent tubes and analyzed by gas chromatography/mass spectrometry (GC/MS). Seven VOCs emitted by VF were quantified. Concentration measurements by FBD ranged from 5.1 microg/g VF for n-hexadecane to 130 microg/g VF for phenol. Concentrations measured by DTD were higher than concentrations measured by FBD. Differences between FBD and DTD results may be explained using free-volume and dual-mobility sorption theory, but further research is necessary to more completely characterize the complex nature of a diffusant in a polymer matrix. PMID:11518293

  18. Production of volatile organic compounds in cultures of cryptophytes

    NASA Astrophysics Data System (ADS)

    Yamakoshi, T.; Kurihara, M.; Hashimoto, S.

    2010-12-01

    Volatile organic compounds (VOCs) are known to be produced by macroalgae, phytoplankton and bacteria in the ocean. Some phytoplankton species are known for the production of VOCs such as halomethanes and isoprene in cultures. To discuss the diversity of VOCs production among phytoplankton species, we incubated the strains of cryptophytes and measured concentrations of VOCs and chlorophyll a. Because VOCs productions of cryptophytes were poorly understood, we selected them to cover the lack of data for VOCs production. Phytoplankton cultures were grown in autoclaved f/2-Si medium with GF/F filtered aged seawater. Culture temperature and light conditions were 24.1 ± 0.2°C and 78 ± 4 μE m-2 s-1 (1 E = 1 mol of photons) from full-spectrum vita-lite fluorescent lamp (12 h light:12 h dark cycle). VOCs concentrations in the medium were measured using a purge and trap (Tekmar PT 5000J)- gas chromatograph (Agilent 6890N)- mass spectrometer (Agilent 5973N). The concentrations of chlorophyll a was also measured using fluorometer (Turner TD-700). Isoprene concentrations were increased to 290 pmol L-1 during the exponential phase in Rhodomonas salina culture. Isoprene production rate was 0.78 μmol g chl.a-1 day-1. This value is within the range of isoprene production by other phytoplankton species reported in the previous paper. As for halomethanes, dibromomethane concentrations were increased during the incubation time. Some iodohalomethanes were also increased during the death phase. We are currently examining the production of halomethanes in other strains of Cryptophyta.

  19. Passive remediation of chlorinated volatile organic compounds using barometric pumping

    SciTech Connect

    Rossabi, J.; Looney, B.B.; Dilek, C.A.E.; Riha, B.; Rohay, V.J.

    1993-12-31

    The purpose of the Savannah River Integrated Demonstration Program, sponsored by the Department of Energy, is to demonstrate new subsurface characterization, monitoring, and remediation technologies. The interbedded clay and sand layers at the Integrated Demonstration Site (IDS) are contaminated with chlorinated volatile organic compounds (CVOCs). Characterization studies show that the bulk of the contamination is located in the approximately 40 m thick vadose zone. The most successful strategy for removing contaminants of this type from this environment is vapor extraction alone or in combination with other methods such as air sparging or enhanced bioremediation. Preliminary work at the IDS has indicated that natural pressure differences between surface and subsurface air caused by surface barometric fluctuations can produce enough gas flow to make barometric pumping a viable method for subsurface remediation. Air flow and pressure were measured in wells that are across three stratigraphic intervals in the vadose zone` The subsurface pressures were correlated to surface pressure fluctuations but were damped and lagging in phase corresponding to depth and stratum permeability. Piezometer wells screened at lower elevations exhibited a greater phase lag and damping than wells screened at higher elevations where the pressure wave from barometric fluctuations passes through a smaller number of low permeable layers. The phase lag between surface and subsurface pressures results in significant fluxes through these wells. The resultant air flows through the subsurface impacts CVOC fate and transport. With the appropriate controls (e.g. solenoid valves) a naturally driven vapor extraction system can be implemented requiring negligible operating costs yet capable of a large CVOC removal rate (as much as 1--2 kg/day in each well at the IDS).

  20. Emission of oxygenated volatile organic compounds (OVOCs) during the aerobic decomposition of orange wastes.

    PubMed

    Wu, Ting; Wang, Xinming

    2015-07-01

    Oxygenated volatile organic compounds (OVOCs) emitted from orange wastes during aerobic decomposition were investigated in a laboratory-controlled incubator for a period of two months. Emission of total OVOCs (TOVOCs) from orange wastes reached 1714 mg/dry kg (330 mg/wet kg). Ethanol, methanol, ethyl acetate, methyl acetate, 2-butanone and acetaldehyde were the most abundant OVOC species with shares of 26.9%, 24.8%, 20.3%, 13.9%, 2.8% and 2.5%, respectively, in the TOVOCs released. The emission fluxes of the above top five OVOCs were quite trivial in the beginning but increased sharply to form one "peak emission window" with maximums at days 1-8 until leveling off after 10 days. This type of "peak emission window" was synchronized with the CO2 fluxes and incubation temperature of the orange wastes, indicating that released OVOCs were mainly derived from secondary metabolites of orange substrates through biotic processes rather than abiotic processes or primary volatilization of the inherent pool in oranges. Acetaldehyde instead had emission fluxes decreasing sharply from its initial maximum to nearly zero in about four days, suggesting that it was inherent rather than secondarily formed. For TOVOCs or all OVOC species except 2-butanone and acetone, over 80% of their emissions occurred during the first week, implying that organic wastes might give off a considerable amount of OVOCs during the early disposal period under aerobic conditions. PMID:26141879

  1. Survey of volatile organic compounds found in indoor and outdoor air samples from Japan.

    PubMed

    Tanaka-Kagawa, Toshiko; Uchiyama, Shigehisa; Matsushima, Erika; Sasaki, Akira; Kobayashi, Hiroshi; Kobayashi, Hiromi; Yagi, Masahiro; Tsuno, Masahiko; Arao, Masa; Ikemoto, Kazumi; Yamasaki, Makoto; Nakashima, Ayako; Shimizu, Yuri; Otsubo, Yasufumi; Ando, Masanori; Jinno, Hideto; Tokunaga, Hiroshi

    2005-01-01

    Indoor air quality is currently a growing concern, mainly due to the incidence of sick building syndrome and building related illness. To better understand indoor air quality in Japan, both indoor and outdoor air samples were collected from 50 residences in Iwate, Yamanashi, Shiga, Hyogo, Kochi and Fukuoka Prefectures. More than 100 volatile organic compounds (VOCs) were analyzed by thermal desorption-gas chromatography/mass spectrometry method. The most abundant class of compounds present in the indoor air samples were identified (i.e. alkanes, alkylbenzenes and terpenes). For 30% of the indoor air samples, the sum of each VOC exceeded the current provisional guideline value for total VOC (TVOC, 400 microg/m3). The major component of these samples included linear and branched-chain alkanes (possibly derived from fossil fuels), 1,4-dichlorobenzene (a moth repellent), alpha-pinene (emission from woody building materials) and limonene (probably derived from aroma products). As an unexpected result, one residence was polluted with an extremely high concentration of 1,1,1,2-tetrafluoroethane (720 microg/m3), suggesting accidental leakage from a household appliance such as a refrigerator. The results presented in this paper are important in establishing the Japanese target compound list for TVOC analysis, as well as defining the current status of indoor air quality in Japan. PMID:16541748

  2. PTR-MS analysis of reference and plant-emitted volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Maleknia, Simin D.; Bell, Tina L.; Adams, Mark A.

    2007-05-01

    Proton transfer reaction-mass spectrometry (PTR-MS) was applied to the analysis of a series of volatile organic compounds (VOCs) that emit from various plants. These include a group of alcohols (methanol, ethanol and butanol), carbonyl-containing compounds (acetic acid, acetone and benzaldehyde), isoprene, acetonitrile, tetrahydrofuran (THF), pyrazine, toluene and xylene and a series of terpenes (p-cymene, camphene, 2-carene, limonene, [beta]-myrcene, [alpha]-pinene, [beta]-pinene, [gamma]-tepinene and terpinolene) and oxygen-containing terpenes (1,8-cineole and linalool). These mass spectral data were compared to an electron ionization (EI) database identifying that not all PTR-MS fragments were common to EI. PTR-MS studies of these reference compounds were utilized to identify VOCs emitted from Eucalyptus grandis leaf at a temperature range of 30-100 °C. In addition to protonated molecules (M + H)+, abundant proton-bound dimers or trimers were detected for alcohols, acetone, acetonitrile and THF. Abundant fragment ions attributed to the loss of water from these proton-bound clusters were also observed. The stability of butyl (C4H9+ m/z 57) and acetyl (CH3CO+ m/z 43) fragment ions directed the proton-transfer reactions of butanol and acetic acid. Abundant (M + H)+ ions were detected for pyrazine, THF, toluene and xylene, as well as for all terpenes except those containing oxygen. For linalool and 1,8-cineole, the loss of water generated an abundant fragment ion at m/z 137. PTR-MS fragmentation patterns for terpenes were proposed for m/z 81 (C6H9+), 93 (C7H9+), 95 (C7H11+), 107 (C8H11+), 109 (C8H13+), 119 (C9H11+), 121 (C9H13+) and 137 (loss of water for oxygen-containing terpenes; C10H17+). The relative abundances of (M + H)+ and fragments for all terpenes (except linalool) were dependent on the drift tube voltage and the optimum voltage for detection of molecular ions was different for various terpenes.

  3. Emission of volatile sulfur compounds during composting of municipal solid waste (MSW)

    SciTech Connect

    Zhang, Hongyu; Schuchardt, Frank; Li, Guoxue; Yang, Jinbing; Yang, Qingyuan

    2013-04-15

    Highlights: ► We compare the volatile sulfur compounds (VSCs) emissions during three types of municipal solid wastes (MSWs) composting. ► The VSCs released from the kitchen waste composting was significantly higher than that from 15–80 mm fraction of MSW. ► Among the five VSCs, H{sub 2}S was the most abundant compound with 39.0–43.0% of total VSCs released. ► Addition of 20% cornstalks could significantly reduce the VSCs emissions during kitchen waste composting. - Abstract: Volatile sulfur compounds (VSCs) are the main source for malodor from composting plants. In this study, the VSCs generated from composting of 15–80 mm municipal solid waste (T0), kitchen waste (T1) and kitchen waste mixed dry cornstalks (T2) were measured in 60 L reactors with forced aeration for a period of 30 days. The VSCs detected in all treatments were hydrogen sulfide (H{sub 2}S), methyl mercaptan (MM), dimethyl sulfide (DMS), carbon bisulfide (CS{sub 2}) and dimethyl disulfide (DMDS). Over 90% of the VSCs emissions occurred during the first 15 days, and reached their peak values at days 4–7. The emission profiles of five VSCs species were significantly correlated with internal materials temperature and outlet O{sub 2} concentration (p < 0.05). Total emissions of the VSCs were 216.1, 379.3 and 126.0 mg kg{sup −1} (dry matter) for T0, T1 and T2, respectively. Among the five VSCs, H{sub 2}S was the most abundant compound with 39.0–43.0% of total VSCs released. Composting of kitchen waste from separate collection posed a negative influence on the VSC and leachate production because of its high moisture content. An addition of dry cornstalks at a mixing ratio of 4:1 (wet weight) could significantly reduce the VSCs emissions and avoid leachate. Compared to pure kitchen waste, VSCs were reduced 66.8%.

  4. Groundwater geochemical and selected volatile organic compound data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2011

    USGS Publications Warehouse

    Huffman, Raegan L.; Frans, L.M.

    2012-01-01

    Previous investigations indicate that concentrations of chlorinated volatile organic compounds are substantial in groundwater beneath the 9-acre former landfill at Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington. Phytoremediation combined with ongoing natural attenuation processes was the preferred remedy selected by the U.S. Navy, as specified in the Record of Decision for the site. The U.S. Navy planted two hybrid poplar plantations on the landfill in spring 1999 to remove and to control the migration of chlorinated volatile organic compounds in shallow groundwater. The U.S. Geological Survey has continued to monitor groundwater geochemistry to ensure that conditions remain favorable for contaminant biodegradation as specified in the Record of Decision. This report presents groundwater geochemical and selected volatile organic compound data collected at Operable Unit 1 by the U.S. Geological Survey during June 20-22, 2011, in support of long-term monitoring for natural attenuation. In 2011, groundwater samples were collected from 13 wells and 9 piezometers. Samples from all wells and piezometers were analyzed for redox sensitive constituents and dissolved gases, and samples from 5 of 13 wells and all piezometers also were analyzed for chlorinated volatile organic compounds. Concentrations of redox sensitive constituents measured in 2011 were consistent with previous years, with dissolved oxygen concentrations all at 0.4 milligram per liter or less; little to no detectable nitrate; abundant dissolved manganese, iron, and methane; and commonly detected sulfide. The reductive declorination byproducts - methane, ethane, and ethene - were either not detected in samples collected from the upgradient wells in the landfill and the upper aquifer beneath the northern phytoremediation plantation or were detected at concentrations less than those measured in 2010. Chlorinated volatile organic compound concentrations in 2011 at most piezometers

  5. 40 CFR 60.112a - 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). 60.112a Section 60.112a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic...

  6. 40 CFR 60.112a - 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). 60.112a Section 60.112a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic...

  7. 40 CFR 60.112a - 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). 60.112a Section 60.112a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic...

  8. 40 CFR 60.112a - 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). 60.112a Section 60.112a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic...

  9. 40 CFR 60.112a - 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). 60.112a Section 60.112a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic...

  10. A Comparison of volatile organic compound profiles from bacteria on poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years the characterization of volatile organic compounds (VOCs) emitted from food-borne bacteria has prompted studies on the development of approaches to utilize the profile of volatiles emitted as a way of detecting contamination. We have examined VOCs from poultry with this in mind. Patt...

  11. Volatile Organic Compounds Produced by Bacteria from the Poultry Processing Environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years the characterization of volatile organic compounds (VOCs) emitted from food-borne bacteria has prompted studies on the development of approaches to utilize the profile of volatiles emitted as a way of detecting contamination. We have examined VOCs from poultry with this in mind. Patt...

  12. Field sampling method for quantifying volatile sulfur compounds from animal feeding operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile sulfur compounds (VSCs) are a major class of chemicals associated with odor from animal feeding operations (AFO). Identifying and quantifying VSCs in air is challenging due to their volatility, reactivity, and low concentrations in ambient air. In the present study, a canister based metho...

  13. Comparison of methods for determining volatile compounds in cheese, milk, and whey powder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but selecting the proper procedures presents challenges. Heat is applied to drive volatiles from the samp...

  14. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    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 Compound... Compound (VOC) emissions from bulk gasoline terminals. On and after the date on which § 60.8(a) requires a... with a vapor collection system designed to collect the total organic compounds vapors displaced...

  15. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    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 Compound... Compound (VOC) emissions from bulk gasoline terminals. On and after the date on which § 60.8(a) requires a... with a vapor collection system designed to collect the total organic compounds vapors displaced...

  16. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    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 Compound... Compound (VOC) emissions from bulk gasoline terminals. On and after the date on which § 60.8(a) requires a... with a vapor collection system designed to collect the total organic compounds vapors displaced...

  17. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    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 Compound... Compound (VOC) emissions from bulk gasoline terminals. On and after the date on which § 60.8(a) requires a... with a vapor collection system designed to collect the total organic compounds vapors displaced...

  18. 75 FR 57412 - Approval and Promulgation of Implementation Plans Alabama: Volatile Organic Compounds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... Compounds AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to... ``volatile organic compounds'' (VOCs) found at Alabama Administrative Code section 335-3-1-.02(gggg). Specifically, the revision would add two compounds (propylene carbonate and dimethyl carbonate) to the list...

  19. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    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 Compound... Compound (VOC) emissions from bulk gasoline terminals. On and after the date on which § 60.8(a) requires a... with a vapor collection system designed to collect the total organic compounds vapors displaced...

  20. Partition of volatile compounds in pea globulin-maltodextrin aqueous two-phase system.

    PubMed

    Nguyen, Thanh Dat; Lafarge, Céline; Murat, Chloé; Mession, Jean-Luc; Cayot, Nathalie; Saurel, Rémi

    2014-12-01

    This study is based on the assumption that the off-flavour of pea proteins might be decreased using the retention of volatile compounds by a mixture with another biopolymer. The partition of volatile compounds in an aqueous system containing pea protein and maltodextrins was followed under thermodynamic incompatibility conditions. Firstly, the phase diagram of the system was established. Then, the partition of aroma compounds between the phase rich in protein and the phase rich in maltodextrin was measured by SPME-GC-MS. There was a transfer of volatile compounds during phase separation. Variations of pH were also used to vary the retention of volatile compounds by proteins. The concentration of volatile compounds in protein solution at pH 2.4 was higher than at pH 7.2. It was possible to increase the transfer of volatile compounds from the phase rich in protein to the phase rich in maltodextrin using the effect of pH on protein denaturation. PMID:24996351

  1. Analysis of volatile compounds of Malaysian Tualang (Koompassia excelsa) honey using gas chromatography mass spectrometry.

    PubMed

    Nurul Syazana, M S; Gan, S H; Halim, A S; Shah, Nurul Syazana Mohamad; Gan, Siew Hua; Sukari, Halim Ahmad

    2013-01-01

    The constituents of honey's volatile compounds depend on the nectar source and differ depending on the place of origin. To date, the volatile constituents of Tualang honey have never been investigated. The objective of this study was to analyze the volatile compounds in local Malaysian Tualang honey. A continuous extraction of Tualang honey using five organic solvents was carried out starting from non-polar to polar solvents and the extracted samples were analysed using gas chromatography-mass spectrometry (GC-MS). Overall, 35 volatile compounds were detected. Hydrocarbons constitute 58.5% of the composition of Tualang honey. Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted compounds such as acids and 5-(Hydroxymethyl) furfural (HMF). This is the first study to describe the volatile compounds in Tualang honey. The use of a simple one tube, stepwise, non-thermal liquid-liquid extraction of honey is a advantageous as it prevents sample loss. Further research to test the clinical benefits of these volatile compounds is recommended. PMID:24146441

  2. Effect of γ-irradiation on volatile compounds of dried Welsh onion ( Allium fistulosum L.)

    NASA Astrophysics Data System (ADS)

    Gyawali, Rajendra; Seo, Hye-Young; Lee, Hyun-Ju; Song, Hyun-Pa; Kim, Dong-Ho; Byun, Myung-Woo; Kim, Kyong-Su

    2006-02-01

    The volatile compounds of γ-irradiated dried Welsh onion were isolated by simultaneous distillation-extraction (SDE) technique and then analyzed by gas chromatography-mass spectrometry (GC-MS) along with their non-irradiated counterparts. A total of 35 volatile compounds were identified in non-irradiated and 1 kGy irradiated samples and 36 volatile compounds were identified in 3, 5, 10 and 20 kGy irradiated samples so far belong to chemical classes of acid, alcohol, aldehyde, ester, furan, ketone and S-containing compound. S-containing compounds were detected as major volatile compounds of all experimental samples. Though the content of several compounds was increased after irradiation, content of major S-containing compounds was found to decreased in the process. Application of high-dose irradiation if required for microbial decontamination of dried Welsh onion is feasible as it enhanced the total concentration of volatile compounds by 31.60% and 24.85% at 10 and 20 kGy, respectively.

  3. COMPARISON OF PROCEDURES TO DETERMINE ADSORPTION CAPACITY OF VOLATILE ORGANIC COMPOUNDS ON ACTIVATED CARBON

    EPA Science Inventory

    Numerous volatile organic compounds (VOCs) are under regulatory consideration for inclusion in the National Primary Drinking Water Standards. Adsorption is a cost-effective treatment technology for control of VOCs. Adsorption capacities were determined for fifteen VOCs in distill...

  4. VOLATILE ORGANIC COMPOUND EMISSION RATES FROM MIXED DECIDUOUS AND CONIFEROUS FORESTS IN NORTHERN WISCONSIN, USA

    EPA Science Inventory

    Biogenic emissions of volatile organic compounds (VOC) from forests play an important role in regulating the atmospheric trace gas composition including global tropospheric ozone concentrations. However, more information is needed on VOC emission rates from different forest regio...

  5. Analysis of breath volatile organic compounds as a screening tool for detection of Tuberculosis in cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    • Keywords: bovine tuberculosis; Mycobacterium bovis; breath analysis; volatile organic compound; gas chromatography; mass spectrometry; NaNose • Introduction: This presentation describes two studies exploring the use of breath VOCs to identify Mycobacterium bovis infection in cattle. • Methods: ...

  6. HS-GC-MS volatile compounds recovered in freshly pressed 'Wonderful' cultivar and commercial pomegranate juices.

    PubMed

    Beaulieu, John C; Stein-Chisholm, R E

    2016-01-01

    Consumption and production of superfruits has been increasing. Highly colored fruits often have bitter and astringent components that may make them undesirable, especially when processed. Many pomegranate volatile reports involved commercial samples, complicated isolation methods, or blending and concentrating that were from arils only, cultivars other than 'Wonderful', or mixed cultivars. Solid phase microextraction (SPME), polydimethylsiloxane stir bar sorptive extraction, and Tenax adsorption were performed with freshly pressed 'Wonderful' juices, commercial juices and concentrates. Using SPME, 36 compounds were isolated in whole pressed 'Wonderful' juices, including 18 of the 21 consensus compounds. In arils-only juices, 41 compounds were isolated by SPME, including 17 of the consensus volatiles. Dramatic variation existed in volatiles recovered in commercial juices and isolation of consensus compounds was sporadic. This article and summary of the literature serves to possibly deliver an improved volatile data set via a rapid method for fresh and partially processed (pressed) pomegranates. PMID:26213022

  7. NEUROTOXIC EFFECTS OF CONTROLLED EXPOSURE TO A COMPLEX MIXTURE OF VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    Subjective reactions of discomfort, impaired air quality, irritation of mucosal membranes, and impaired memory have been reported in chemically sensitive subjects during exposure to volatile organic compounds (VOC's) found in new buildings. 6 normal healthy male subjects aged 18-...

  8. EVALUATION OF THE WALKTHROUGH SURVEY METHOD FOR DETECTION OF VOLATILE ORGANIC COMPOUND LEAKS

    EPA Science Inventory

    During 1978 and 1979, the Emission Standards and Engineering Division of EPA's Office of Air Quality Planning and Standards conducted a fugitive volatile organic compound (VOC) emission sampling program in organic chemical manufacturing plants and petroleum refineries. As a part ...

  9. Recovery of several volatile organic compounds from simulated water samples: Effect of transport and storage

    USGS Publications Warehouse

    Friedman, L.C.; Schroder, L.J.; Brooks, M.G.

    1986-01-01

    Solutions containing volatile organic compounds were prepared in organic-free water and 2% methanol and submitted to two U.S. Geological Survey laboratories. Data from the determination of volatile compounds in these samples were compared to analytical data for the same volatile compounds that had been kept in solutions 100 times more concentrated until immediately before analysis; there was no statistically significant difference in the analytical recoveries. Addition of 2% methanol to the storage containers hindered the recovery of bromomethane and vinyl chloride. Methanol addition did not enhance sample stability. Further, there was no statistically significant difference in results from the two laboratories, and the recovery efficiency was more than 80% in more than half of the determinations made. In a subsequent study, six of eight volatile compounds showed no significant loss of recovery after 34 days.

  10. VOLATILE ORGANIC COMPOUND DETERMINATIONS USING SURROGATE-BASED CORRECTION FOR METHOD AND MATRIX EFFECTS

    EPA Science Inventory

    The principal properties related to analyte recovery in a vacuum distillate are boiling point and relative volatility. The basis for selecting compounds to measure the relationship between these properties and recovery for a vacuum distillation is presented. Surrogates are incorp...

  11. HENRY'S LAW CONSTANTS AND MICELLAR PARTITIONING OF VOLATILE ORGANIC COMPOUNDS IN SURFACTANT SOLUTIONS

    EPA Science Inventory

    Partitioning of volatile organic compounds (VOCs) into surfactant micelles affects the apparent vapor-liquid equilibrium of VOCs in surfactant solutions. This partitioning will complicate removal of VOCs from surfactant solutions by standard separation processes. Headspace expe...

  12. A Multi-Wavelength Study of Parent Volatile Abundances in Comet C/2006 M4 (SWAN)

    NASA Technical Reports Server (NTRS)

    DiSanti, Michael A.; Villanueva, Geronimo L.; Milam, Stefanie N.; Zack, Lindsay N.; Bonev, Boncho P.; Mumma, Michael; Ziurys, Lucy M.; Anderson, William M.

    2009-01-01

    Volatile organic emissions were detected post-perihelion in the long period comet C/2006 M4 (SWAN) in October and November 2006. Our study combines target-of-opportunity, observations using the infrared Cryogenic Echelle Spectrometer (CSHELL) at the NASA-IRTF 3-m telescope, and millimeter wavelength observations using the Arizona Radio Observatory (ARO) 12-m telescope. Five parent volatiles were measured with CSHELL (H2O, CO, CH3OH, CH4, and C2H6), and two additional species (HCN and CS) were measured with the ARID 12-m. These revealed highly depleted CO and somewhat enriched CH3OH compared with abundances observed in the dominant group of long-period (Oort cloud) comets in our sample and similar to those observed recently in Comet 8P/Tuttle. This may indicate highly efficient H-atom addition to CO at very low temperature (approx.10-20 K) on the surfaces of interstellar (pre-cometary) grains. Comet C12006 M4 had nearly "normal" C2H6, and CH4, suggesting a processing history similar to that experienced by the dominant group. When compared with estimated water production at the time of the millimeter observations, HCN was slightly depleted compared with the normal abundance in comets based on 1R observations but was consistent with the majority of values from the millimeter. The ratio CS/HCN in C/2006 M4 was within the range measured in ten comets at millimeter wavelengths. The higher apparent H-atom conversion efficiency compared with most comets may indicate that the icy grains incorporated into C/2006 M4 were exposed to higher H-atom densities, or alternatively to similar densities but for a longer period of time.

  13. 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.

  14. Release and uptake of volatile organic compounds by human hepatocellular carcinoma cells (HepG2) in vitro

    PubMed Central

    2013-01-01

    Background Volatile organic compounds (VOCs) emitted by human body offer a unique insight into biochemical processes ongoing in healthy and diseased human organisms. Unfortunately, in many cases their origin and metabolic fate have not been yet elucidated in sufficient depth, thus limiting their clinical application. The primary goal of this work was to identify and quantify volatile organic compounds being released or metabolized by HepG2 hepatocellular carcinoma cells. Methods The hepatocellular carcinoma cells were incubated in specially designed head-space 1-L glass bottles sealed for 24 hours prior to measurements. Identification and quantification of volatiles released and consumed by cells under study were performed by gas chromatography with mass spectrometric detection (GC-MS) coupled with head-space needle trap device extraction (HS-NTD) as the pre-concentration technique. Most of the compounds were identified both by spectral library match as well as retention time comparison based on standards. Results A total of nine compounds were found to be metabolised and further twelve released by the cells under study (Wilcoxon signed-rank test, p<0.05). The former group comprised 6 aldehydes (2-methyl 2-propenal, 2-methyl propanal, 2-ethylacrolein, 3-methyl butanal, n-hexanal and benzaldehyde), n-propyl propionate, n-butyl acetate, and isoprene. Amongst the released species there were five ketones (2-pentanone, 3-heptanone, 2-heptanone, 3-octanone, 2-nonanone), five volatile sulphur compounds (dimethyl sulfide, ethyl methyl sulfide, 3-methyl thiophene, 2-methyl-1-(methylthio)- propane and 2-methyl-5-(methylthio) furan), n-propyl acetate, and 2-heptene. Conclusions The emission and uptake of the aforementioned VOCs may reflect the activity of abundant liver enzymes and support the potential of VOC analysis for the assessment of enzymes function. PMID:23870484

  15. 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

  16. Volatile Organic Compound Investigation Results, 300 Area, Hanford Site, Washington

    SciTech Connect

    Peterson, Robert E.; Williams, Bruce A.; Smith, Ronald M.

    2008-07-07

    Unexpectedly high concentrations of volatile organic compounds (VOC) were discovered while drilling in the unconfined aquifer beneath the Hanford Site’s 300 Area during 2006. The discovery involved an interval of relatively finer-grained sediment within the unconfined aquifer, an interval that is not sampled by routine groundwater monitoring. Although VOC contamination in the unconfined aquifer has been identified and monitored, the concentrations of newly discovered contamination are much higher than encountered previously, with some new results significantly higher than the drinking water standards. The primary contaminant is trichloroethene, with lesser amounts of tetrachloroethene. Both chemicals were used extensively as degreasing agents during the fuels fabrication process. A biological degradation product of these chemicals, 1,2-dichloroethene, was also detected. To further define the nature and extent of this contamination, additional characterization drilling was undertaken during 2007. Four locations were drilled to supplement the information obtained at four locations drilled during the earlier investigation in 2006. The results of the combined drilling indicate that the newly discovered contamination is limited to a relatively finer-grained interval of Ringold Formation sediment within the unconfined aquifer. The extent of this contamination appears to be the area immediately east and south of the former South Process Pond. Samples collected from the finer-grained sediment at locations along the shoreline confirm the presence of the contamination near the groundwater/river interface. Contamination was not detected in river water that flows over the area where the river channel potentially incises the finer-grained interval of aquifer sediment. The source for this contamination is not readily apparent. A search of historical documents and the Hanford Waste Information Data System did not provide definitive clues as to waste disposal operations and

  17. Biological aspects of constructing volatile organic compound emission inventories

    NASA Astrophysics Data System (ADS)

    Monson, Russell K.; Lerdau, Manuel T.; Sharkey, Thomas D.; Schimel, David S.; Fall, Ray

    The: emission of volatile organic compounds (VOCs) from vegetation is subject to numerous biological controls. Past inventories have relied heavily on empirical models which are limited in their ability to simulate the response of organisms to short- and long-term changes in their growth environment. In this review we consider the principal biochemical, physiological and ecological controls over VOC emission with specific reference to how such controls can be included in ecosystem-level inventories. A distinction is made between longer-term biological controls over basal VOC emission rates (rates determined under a standard set of environmental conditions) and instantaneous biological and environmental controls over instantaneous VOC emission rates (rates determined at the prevailing, instantaneous set of environmental conditions). Emphasis is placed on the emission of isoprene and monoterpenes. Isoprene emission occurs essentially without a leaf reservoir and is tightly linked to instantaneous photosynthetic metabolism and the activity of isoprene synthase, the enzyme that underlies isoprene production. At present, there are still large uncertainties about which of these controls dominates isoprene emission rate. Ecosystem-level inventories of isoprene emission would be best handled through consideration of (1) the early season induction of isoprene emission, (2) seasonal and spatial variability in light, nitrogen and water availability and their influences on the basal emission rate, and (3) the influence of instantaneous changes in light and temperature on the basal emission rate. Monoterpene emission occurs from a large leaf reservoir, is uncoupled from instantaneous controls over biosynthesis, and is likely linked to whole-plant carbon allocation patterns. Because of the well-defined role of monoterpenes as herbivore deterrents and their linkage to plant carbon balance, there is promise for ecosystem-level inventories based on biological resource allocation

  18. Effects of rigorous emission controls on reducing ambient volatile organic compounds in Beijing, China.

    PubMed

    Li, Jing; Wu, Rongrong; Li, Yaqi; Hao, Yufang; Xie, Shaodong; Zeng, Liming

    2016-07-01

    102 volatile organic compound (VOC) species were measured online using a gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID) at an urban site in Beijing in 11 August to 3 September 2015, when a series of rigorous air quality control measures were implemented in Beijing city and neighbouring provinces. Positive matrix factorization (PMF) was applied to identify emission sources from 1h averaged values of VOC data. Based on the online VOC data and the PMF analysis results, the effectiveness of different control measures were investigated. The PMF results were compared with an emission inventory data. Results show that the rigorous air quality restrictions implemented were successful. The averaged ambient VOC mixing ratios during the emission control period and non-control period were 27.53 and 45.42ppbv, respectively. The mixing ratios of total VOC during the control period were reduced by 40%. Alkanes were the most abundant chemical group in the two periods, followed by oxygenated volatile organic compounds (OVOCs). Almost all quantified VOC species decreased during the control period. Tracers of industrial sources and vehicle exhaust reduced most, including some halocarbons, esters and aromatics. Eight sources were resolved by online PMF analysis for ambient VOCs in Beijing. Contributions of those sources varied significantly during the control and non-control period. Compared with the values before control, contributions of vehicle-related sources were most reduced, followed by solvent utilization. Reductions of vehicle-related sources, solvent utilization, secondary formation, fuel combustion, and biogenic were responsible for 65%, 19%, 10%, 5%, and 1% of the reductions in ambient VOCs. Both PMF results and emission inventory data indicated that the control measure on traffic was very effective in reducing ambient VOCs in Beijing, with the emission reductions of about 50%. PMID:27039059

  19. Consumer palatability scores and volatile beef flavor compounds of five USDA quality grades and four muscles.

    PubMed

    Legako, J F; Brooks, J C; O'Quinn, T G; Hagan, T D J; Polkinghorne, R; Farmer, L J; Miller, M F

    2015-02-01

    Proximate data, consumer palatability scores and volatile compounds were investigated for four beef muscles (Longissimus lumborum, Psoas major, Semimembranosus and Gluteus medius) and five USDA quality grades(Prime, Upper 2/3 Choice, Low Choice, Select, and Standard). Quality grade did not directly affect consumer scores or volatiles but interactions (P < 0.05) between muscle and grade were determined. Consumer scores and volatiles differed (P < 0.05) between muscles. Consumers scored Psoas major highest for tenderness, juiciness, flavor liking and overall liking, followed by Longissimus lumborum, Gluteus medius, and Semimembranosus (P < 0.05). Principal component analysis revealed clustering of compound classes, formed by related mechanisms. Volatile n-aldehydes were inversely related to percent fat. Increases in lipid oxidation compounds were associated with Gluteus medius and Semimembranosus, while greater quantities of sulfur-containing compounds were associated with Psoas major. Relationships between palatability scores and volatile compound classes suggest that differences in the pattern of volatile compounds may play a valuable role in explaining consumer liking. PMID:25460139

  20. 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. PMID:16865344

  1. Analysis of volatile organic compounds of ‘Fuji’ apples following electron beam irradiation and storage

    NASA Astrophysics Data System (ADS)

    Song, Hyun-Pa; Shim, Sung-Lye; Lee, Sun-Im; Kim, Dong-Ho; Kwon, Joong-Ho; Kim, Kyong-Su

    2012-08-01

    The volatile organic compounds of non-irradiated and electron-beam irradiated 'Fuji' apples (Malus domestica Borkh.) at 0, 0.5, and 1 kGy were isolated through simultaneous distillation extractions and analyzed using gas chromatograph-mass spectrometry. A total of 53 volatile organic compounds were characterized in 0 and 1 kGy irradiated samples, whereas two more compounds related to ketone and terpenoid group were identified in 0.5 kGy irradiated samples. The contents of volatile compounds were 24.33, 36.49, and 35.28 mg/kg in 0, 0.5, and 1 kGy irradiated samples, respectively. The major compounds identified were butanol, hexanal, [E]-2-hexenal, and hexanol in all samples. The relative content of alcohol increased after 30 days of storage in all samples, whereas that of aldehyde decreased. Although the contents of some volatile compounds were changed by electron-beam irradiation, the total yield and major flavor compounds of irradiated 'Fuji' apples were similar to, or even greater than, those of the control. Therefore, the application of e-beam irradiation if required for microbial decontamination of 'Fuji' apples is an acceptable method as it does not bring about any major quantitative changes of volatile organic compounds.

  2. 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. PMID:23273472

  3. Volatile Abundances and the D/H Ratio in Long-Period Comets

    NASA Astrophysics Data System (ADS)

    Weaver, Harold

    2003-07-01

    Comet NEAT {C/2001 Q4} is predicted to reach naked-eye visibility in the spring of 2004, under excellent conditions for observations with HST. Although predicting cometary magnitudes more than 1 year in advance is notoriously risky, C/NEAT seems likely to be exceptionally active, allowing us for the first time to perform sensitive measurements of the D/H and OD/OH ratios. Accurate measurements of the deuterium abundance in comets, which can vary in different species, are crucial for determining if comets retain a signature of their possible interstellar origin and if they supplied a significant fraction of the water on Earth. HST observations of C/NEAT will additionally provide accurate abundances for highly volatile ices in the nucleus, such as CO, CO2 {via Cameron band emission}, and S2, which also provide important insights on the comet's origin and evolution. This opportunity in cycle 12 is unique in the history of HST and is unlikely to be repeated during its remaining lifetime.

  4. Inhibition of Pseudogymnoascus destructans growth from conidia and mycelial extension by bacterially produced volatile organic compounds.

    PubMed

    Cornelison, Christopher T; Gabriel, Kyle T; Barlament, Courtney; Crow, Sidney A

    2014-02-01

    The recently identified causative agent of white-nose syndrome (WNS), Pseudogymnoascus destructans, has been implicated in the mortality of an estimated 5.5 million North American bats since its initial documentation in 2006 (Frick et al. in Science 329:679-682, 2010). In an effort to identify potential biological and chemical control options for WNS, 6 previously described bacterially produced volatile organic compounds (VOCs) were screened for anti-P. destructans activity. The compounds include decanal; 2-ethyl-1-hexanol; nonanal; benzothiazole; benzaldehyde; andN,N-dimethyloctylamine. P. destructans conidia and mycelial plugs were exposed to the VOCs in a closed air space at 15 and 4 °C and then evaluated for growth inhibition. All VOCs inhibited growth from conidia as well as inhibiting radial mycelial extension, with the greatest effect at 4 °C. Studies of the ecology of fungistatic soils and the natural abundance of the fungistatic VOCs present in these environments suggest a synergistic activity of select VOCs may occur. The evaluation of formulations of two or three VOCs at equivalent concentrations was supportive of synergistic activity in several cases. The identification of bacterially produced VOCs with anti-P. destructans activity indicates disease-suppressive and fungistatic soils as a potentially significant reservoir of biological and chemical control options for WNS and provides wildlife management personnel with tools to combat this devastating disease. PMID:24190516

  5. Removal of volatile organic compounds using amphiphilic cyclodextrin-coated polypropylene.

    PubMed

    Lumholdt, Ludmilla; Fourmentin, Sophie; Nielsen, Thorbjørn T; Larsen, Kim L

    2014-01-01

    Polypropylene nonwovens were functionalised using a self-assembled, amphiphilic cyclodextrin coating and the potential for water purification by removal of pollutants was studied. As benzene is one of the problematic compounds in the Water Framework Directive, six volatile organic compounds (benzene and five benzene-based substances) were chosen as model compounds. The compounds were tested as a mixture in order to provide a more realistic situation since the wastewater will be a complex mixture containing multiple pollutants. The volatile organic compounds are known to form stable inclusion complexes with cyclodextrins. Six different amphiphilic cyclodextrin derivatives were synthesised in order to elucidate whether or not the uptake abilities of the coating depend on the structure of the derivative. Headspace gas chromatography was used for quantification of the uptake exploiting the volatile nature of benzene and its derivatives. The capacity was shown to increase beyond the expected stoichiometries of guest-host complexes with ratios of up to 16:1. PMID:25550739

  6. Halogenated volatile organic compounds from the use of chlorine-bleach-containing household products.

    PubMed

    Odabasi, Mustafa

    2008-03-01

    Sodium hypochlorite (NaOCl) and many organic chemicals contained in household cleaning products may react to generate halogenated volatile organic compounds (VOCs). Halogenated VOC emissions from eight different chlorine bleach containing household products (pure and diluted) were investigated by headspace experiments. Chloroform and carbon tetrachloride were the leading compounds along with several halogenated compounds in the headspace of chlorine bleach products. One of the most surprising results was the presence of carbon tetrachloride (a probable human carcinogen and a powerful greenhouse gas that was banned for household use by the U.S. Food and Drug Administration) in very high concentrations (up to 101 mg m(-3)). By mixing surfactants or soap with NaOCl, it was shown that the formation of carbon tetrachloride and several other halogenated VOCs is possible. In addition to quantitatively determined halogenated VOCs (n = 15), several nitrogen-containing (n = 4), chlorinated (n = 10), oxygenated compounds (n = 22), and hydrocarbons (n = 14) were identified in the headspace of bleach products. Among these, 1,1-dichlorobutane and 2-chloro-2-nitropropane were the most abundant chlorinated VOCs, whereas trichloronitromethane and hexachloroethane were the most frequently detected ones. Indoor air halogenated VOC concentrations resulting from the use of four selected household products were also measured before, during, and 30 min after bathroom, kitchen, and floor cleaning applications. Chloroform (2.9-24.6 microg m(-3)) and carbon tetrachloride (0.25-459 microg m(-3)) concentrations significantly increased during the use of bleach containing products. During/ before concentration ratios ranged between 8 and 52 (25 +/- 14, average +/- SD) for chloroform and 1-1170 (146 +/- 367, average +/- SD) for carbon tetrachloride, respectively. These results indicated that the bleach use can be important in terms of inhalation exposure to carbon tetrachloride, chloroform and

  7. Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity

    NASA Astrophysics Data System (ADS)

    Karl, T.; Apel, E.; Hodzic, A.; Riemer, D. D.; Blake, D. R.; Wiedinmyer, C.

    2009-01-01

    Toluene and benzene are used for assessing the ability to measure disjunct eddy covariance (DEC) fluxes of Volatile Organic Compounds (VOC) using Proton Transfer Reaction Mass Spectrometry (PTR-MS) on aircraft. Statistically significant correlation between vertical wind speed and mixing ratios suggests that airborne VOC eddy covariance (EC) flux measurements using PTR-MS are feasible. City-median midday toluene and benzene fluxes are calculated to be on the order of 14.1±4.0 mg/m2/h and 4.7±2.3 mg/m2/h, respectively. For comparison the adjusted CAM2004 emission inventory estimates toluene fluxes of 10 mg/m2/h along the footprint of the flight-track. Wavelet analysis of instantaneous toluene and benzene measurements during city overpasses is tested as a tool to assess surface emission heterogeneity. High toluene to benzene flux ratios above an industrial district (e.g. 10-15 g/g) including the International airport (e.g. 3-5 g/g) and a mean flux (concentration) ratio of 3.2±0.5 g/g (3.9±0.3 g/g) across Mexico City indicate that evaporative fuel and industrial emissions play an important role for the prevalence of aromatic compounds. Based on a tracer model, which was constrained by BTEX (BTEX- Benzene/Toluene/Ethylbenzene/m, p, o-Xylenes) compound concentration ratios, the fuel marker methyl-tertiary-butyl-ether (MTBE) and the biomass burning marker acetonitrile (CH3CN), we show that a combination of industrial, evaporative fuel, and exhaust emissions account for >87% of all BTEX sources. Our observations suggest that biomass burning emissions play a minor role for the abundance of BTEX compounds in the MCMA (2-13%).

  8. Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity

    NASA Astrophysics Data System (ADS)

    Karl, T.; Apel, E.; Hodzic, A.; Riemer, D.; Blake, D.; Wiedinmyer, C.

    2008-07-01

    Toluene and benzene are used for assessing the ability to measure disjunct eddy covariance (DEC) fluxes of Volatile Organic Compounds (VOC) using Proton Transfer Reaction Mass Spectrometry (PTR-MS) on aircraft. Statistically significant correlation between vertical wind speed and mixing ratios suggests that airborne VOC eddy covariance (EC) flux measurements using PTR-MS are feasible. City-average midday toluene and benzene fluxes are calculated to be on the order of 15.5±4.0 mg/m2/h and 4.7±2.3 mg/m2/h respectively. These values argue for an underestimation of toluene and benzene emissions in current inventories used for the Mexico City Metropolitan Area (MCMA). Wavelet analysis of instantaneous toluene and benzene measurements during city overpasses is tested as a tool to assess surface emission heterogeneity. High toluene to benzene flux ratios above an industrial district (e.g. 10 15) including the International airport (e.g. 3 5) and a mean flux (concentration) ratio of 3.2±0.5 (3.9±0.3) across Mexico City indicate that evaporative fuel and industrial emissions play an important role for the prevalence of aromatic compounds. Based on a tracer model, which was constrained by BTEX (Benzene/Toluene/Ethylbenzene/m,p,o-Xylenes) compound concentration ratios, the fuel marker methyl-tertiary-butyl-ether (MTBE) and the biomass burning marker acetonitrile (CH3CN), we show that a combination of industrial, evaporative fuel, and exhaust emissions account for >90% of all BTEX sources. Our observations suggest that biomass burning emissions play a minor role for the abundance of BTEX compounds (0 10%) in the MCMA.

  9. Effect of γ-irradiation on the volatile compounds of medicinal herb, Paeoniae Radix

    NASA Astrophysics Data System (ADS)

    Shim, Sung-Lye; Hwang, In-Min; Ryu, Keun-Young; Jung, Min-Seok; Seo, Hye-young; Kim, Hee-Yeon; Song, Hyun-Pa; Kim, Jae-Hun; Lee, Ju-Woon; Byun, Myung-Woo; Kwon, Joong-Ho; Kim, Kyong-Su

    2009-07-01

    A study was carried out to find the effect of γ-irradiation on contents of volatile compounds from medicinal herb, Paeoniae Radix ( Paenia albiflora Pallas var. trichocarpa Bunge). The volatile compounds of control, 1, 3, 5 and 10 kGy irradiated samples were extracted by simultaneous steam distillation and extraction (SDE) method and analyzed by gas chromatograph-mass spectrometer. The major volatile compounds were paeonol, ( E)-carveol, ( E, E)-2,4-octadienal, methyl salicylate, myrtanol and eugenol acetate. Volatile compounds belonging to chemical classes of acids, alcohols, aldehydes, esters, hydrocarbons and miscellaneous were identified in all experimental samples. The types of volatile compounds in irradiated samples were similar to those of non-irradiated sample and the concentrations of these compounds differed between treatments. 1,3-Bis (1,1-dimethylethyl)-benzene was identified by using the selected ion monitoring (GC/MS-SIM) mode. The concentration of this compound increased with the increase of irradiation dose level. These results suggest that it could be used as the base data for the effect of γ-irradiation on medicinal herb.

  10. The Influence of Spices on the Volatile Compounds of Cooked Beef Patty.

    PubMed

    Jung, Samooel; Jo, Cheorun; Kim, Il Suk; Nam, Ki Chang; Ahn, Dong Uk; Lee, Kyung Heang

    2014-01-01

    The aim of this study is to examine the influences of spices on the amounts and compositions of volatile compounds released from cooked beef patty. Beef patty with 0.5% of spice (nutmeg, onion, garlic, or ginger powder, w/w) was cooked by electronic pan until they reached an internal temperature of 75℃. A total of 46 volatile compounds (6 alcohols, 6 aldehydes, 5 hydrocarbons, 6 ketones, 9 sulfur compounds, and 14 terpenes) from cooked beef patties were detected by using purgeand- trap GC/MS. The addition of nutmeg, onion, or ginger powder significantly reduced the production of the volatile compounds via lipid oxidation in cooked beef patty when compared to those from the control. Also, the addition of nutmeg and garlic powder to beef patty generated a lot of trepans or sulfur volatile compounds, respectively. From these results, the major proportion by chemical classes such as alcohols, aldehydes, hydrocarbons, ketones, sulfur compounds, and terpenes was different depending on the spice variations. The results indicate that addition of spices to the beef patty meaningfully changes the volatile compounds released from within. Therefore, it can be concluded that spices can interact with meat aroma significantly, and thus, the character of each spice should be considered before adding to the beef patty. PMID:26760934

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

    In this research, we investigated the sorptive behavior of a mixture of 14 volatile and semi-volatile organic compounds (four aromatic hydrocarbons (benzene, toluene, p-xylene, and styrene), six C2-C5 volatile fatty acids (VFAs), two phenols, and two indoles) against three metal-organic frameworks (MOFs), i.e., MOF-5, Eu-MOF, and MOF-199 at 5 to 10 mPa VOC partial pressures (25 °C). The selected MOFs exhibited the strongest affinity for semi-volatile (polar) VOC molecules (skatole), whereas the weakest affinity toward was volatile (non-polar) VOC molecules (i.e., benzene). Our experimental results were also supported through simulation analysis in which polar molecules were bound most strongly to MOF-199, reflecting the presence of strong interactions of Cu(2+) with polar VOCs. In addition, the performance of selected MOFs was compared to three well-known commercial sorbents (Tenax TA, Carbopack X, and Carboxen 1000) under the same conditions. The estimated equilibrium adsorption capacity (mg.g(-1)) for the all target VOCs was in the order of; MOF-199 (71.7) >Carboxen-1000 (68.4) >Eu-MOF (27.9) >Carbopack X (24.3) >MOF-5 (12.7) >Tenax TA (10.6). Hopefully, outcome of this study are expected to open a new corridor to expand the practical application of MOFs for the treatment diverse VOC mixtures. PMID:27324522

  14. SAW/GC detection of taggants and other volatile compounds associated with contraband materials

    NASA Astrophysics Data System (ADS)

    Staples, Edward J.; Watson, Gary W.; McGuirre, David S.; Williams, Dudley

    1997-02-01

    Research on a Surface Acoustic Wave (SAW) Gas Chromatography (GC) non-intrusive inspection system has demonstrated the ability to identify and quantify the presence of non- volatile contraband vapors in less than 10 seconds. The technique can be used to detect volatile compounds associated with the contraband compound as well. This is important because volatile taggants in explosives make them easy to detect and volatile organic compounds are routinely used in the manufacturing of illicit drugs. The results of tests with volatile organic compounds associated with drugs of abuse, and volatile taggants for explosives are presented. The latter materials are particularly useful in detecting plastic explosives and results for Semtex and C-4 spiked with a taggant show that detectability is improved. Similar testing protocols and methods for drugs, currency, organo-phosphate agents, and taggant compounds have also been demonstrated. The SAW/GC method needs no high voltages, utilizes essentially all solid state devices, and involves no radioactive or hazardous materials SAW detection systems have demonstrated dynamic ranges greater than 1,000,000 and the ability to selectively screen for vapors from explosive and drugs of abuse at the part per billion level with little or no interference. Most important for law-enforcement, SAW/GC devices can be produced in small packages at low cost.

  15. What is the link of the abundances of volatile species in the coma with the ones in the nucleus ?

    NASA Astrophysics Data System (ADS)

    Marboeuf, U.; Schmitt, B.

    2014-04-01

    The chemical composition of comets is frequently assumed to be directly provided by the observations of the abundances of volatile molecules in the coma. The present work aims to determine the relationship between the chemical composition of the coma, the outgassing profile of volatile molecules and the physicochemical composition of the nucleus. To do this, we have developed a quasi 3D model of a cometary nucleus which takes into account all phase changes and water ice structures and applied this model to the comet 67P/Churyumov-Gerasimenko, the target of the Rosetta mission. We find that the outgassing profile of volatile molecules is a strong indicator of the physical and thermal properties of the solid nucleus. The relative abundance (to H2O) of volatile molecules released from the nucleus interior varies by some orders of magnitude as a function of the distance to the sun, the volatility of species, their abundance and distribution between the 'trapped' and 'condensed' states, the structure of water ice, and the thermal inertia and other physical assumptions (dust mantle, ...) on the nucleus.

  16. EFFECTS IN HUMANS OF A VOLATILE ORGANIC COMPOUND MIXTURE: SENSORY

    EPA Science Inventory

    Time-course actions for symptoms of the sick building syndrome were derived from 66 healthy males exposed to clean air and a volatile organic (VOC) mixture in separate sessions. he mixture contained 22 VOCs (25 mg/m3 total concentration) commonly found air-borne in new or recentl...

  17. Headspace solid-phase microextraction-gas chromatography-mass spectrometry characterization of propolis volatile compounds.

    PubMed

    Pellati, Federica; Prencipe, Francesco Pio; Benvenuti, Stefania

    2013-10-01

    In this study, a novel and efficient method based on headspace solid-phase microextraction (HS-SPME), followed by gas chromatography-mass spectrometry (GC-MS), was developed for the analysis of propolis volatile compounds. The HS-SPME procedure, whose experimental parameters were properly optimized, was carried out using a 100 μm polydimethylsiloxane (PDMS) fiber. The GC-MS analyses were performed on a HP-5 MS cross-linked 5% diphenyl-95% dimethyl polysiloxane capillary column (30 m × 0.25 mm I.D., 1.00 μm film thickness), under programmed-temperature elution. Ninety-nine constituents were identified using this technique in the samples of raw propolis collected from different Italian regions. The main compounds detected include benzoic acid (0.87-30.13%) and its esters, such as benzyl benzoate (0.16-13.05%), benzyl salicylate (0.34-1.90%) and benzyl cinnamate (0.34-3.20%). Vanillin was detected in most of the samples analyzed in this study (0.07-5.44%). Another relevant class of volatile constituents is represented by sesquiterpene hydrocarbons, such as δ-cadinene (1.29-13.31%), γ-cadinene (1.36-8.85%) and α-muurolene (0.78-6.59%), and oxygenated sesquiterpenes, such as β-eudesmol (2.33-12.83%), T-cadinol (2.73-9.95%) and α-cadinol (4.84-9.74%). Regarding monoterpene hydrocarbons, they were found to be present at low level in the samples analyzed in this study, with the exception of one sample from Southern Italy, where α-pinene was the most abundant constituent (13.19%). The results obtained by HS-SPME-GC-MS were also compared with those of hydrodistillation (HD) coupled with GC-MS. The HS-SPME-GC-MS method developed in this study allowed us to determine the chemical fingerprint of propolis volatile constituents, thus providing a new and reliable tool for the complete characterization of this biologically active apiary product. PMID:23807002

  18. [Health effect of volatile aldehyde compounds in photocatalytic oxidation of aromatics compounds].

    PubMed

    Zhao, Wei-rong; Liao, Qiu-wen; Yang, Ya-nan; Dai, Jiu-song

    2013-05-01

    Photocatalytic oxidation (PCO) of toluene and benzaldehyde in indoor air by N doped TiO2 (N-TiO2) was conducted under UV irradiation of 254 nm. The intermediates were identified and monitored on real-time by proton transfer reaction-mass spectrometry. The health risks of PCO of toluene and benzaldehyde were assessed based on health risk influence index (eta). Results indicated that both the conversion rate and mineralization rate of toluene and benzaldehyde were relatively high, however, the volatile aldehyde compounds (VAs), including acetaldehyde and formaldehyde generated from ring-opening, significantly influenced the health risks of PCO of toluene and benzaldehyde. Acetaldehyde played a crucial role on health risks, which was inclined to desorb from the surface of catalysts, accumulate in gas-phase, and increase the health risks of PCO of the aromatic compounds. The concentration of formaldehyde kept stable at a relatively low level, however its impact cannot be neglected. In the PCO process of toluene and benzaldehyde, eta reached the maximum values of 8 499.68 and 21.43, with the eta(VAs), contribution of VAs to the health risk influence index of outlet, reaching 99.3% and 98.3%, respectively. The average values of eta in the PCO process of 30 min were 932.86 and 8.52, and for which eta(VAs), reached 98.5% and 98.0%, respectively. When PCO of toluene and benzaldehyde reached steady state, eta were 236.09 and 2.30, and eta(VAs) reached 97.9% and 97.8%, respectively. Hence, eta(VAs), can be taken as a characteristic parameter in assessment of health risks of PCO of aromatic compounds. PMID:23914541

  19. REVIEW OF VOLATILE ORGANIC COMPOUND SOURCE APPORTIONMENT BY CHEMICAL MASS BALANCE. (R826237)

    EPA Science Inventory

    The chemical mass balance (CMB) receptor model has apportioned volatile organic compounds (VOCs) in more than 20 urban areas, mostly in the United States. These applications differ in terms of the total fraction apportioned, the calculation method, the chemical compounds used ...

  20. DETERMINATION OF POLAR VOLATILE ORGANIC COMPOUNDS IN WATER BY MEMBRANE PERMEATE AND TRAP GC-MS

    EPA Science Inventory

    A novel approach is presented combining semipermeable membranes with the accepted purge and trap gas chromatography-mass spectrometry (GC-MS) technology to produce a method of selectively extracting polar, volatile organic compounds from water, particularly those compounds not am...

  1. Volatile compounds from roots, stems and leaves of Angelica acutiloba growing in Taiwan.

    PubMed

    Chen, Hsin-Chun; Tsaia, Yi-; Linb, Li-Yun; Wu, Chin-Sheng; Tai, Shan-Pao; Chen, Yu-Chang; Chiang, Hsiu-Mei

    2014-04-01

    The present study analyzed and compared the volatile compounds in fresh Angelica acutiloba roots, stems and leaves both qualitatively and quantitatively. The volatile compounds were isolated by either steam distillation (SD) or headspace-solid phase microextraction (HS-SPME). A total of 61 compounds were identified using gas chromatography/mass spectrometry (GC/MS). All 61 compounds were verified by SD, with 3n-butyl phthalide, gamma-terpinene, p-cymene and cis-beta-ocimene as the main compounds. Thirty-three compounds were verified by HS-SPME, with gamma-terpinene and p-cymene as the main compounds. The leaf samples contained the highest essential oil content. Compared with SD, HS-SPME sampling resulted in relatively higher amounts of highly volatile monoterpenes and lower amounts of less volatile compounds such as 3n-butyl phthalide. These findings demonstrate that A. acutiloba roots, stems and leaves have high 3n-butyl phthalide contents; thus, all parts of A. acutiloba may be used for further application and development. PMID:24868890

  2. Comparison of methods for determining volatile compounds in milk, cheese, and whey powder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but conditions have to be adjusted for optimal SPME release while not generating new compounds that are abs...

  3. 77 FR 14279 - National Volatile Organic Compound Emission Standards for Aerosol Coatings-Addition of Dimethyl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ...The EPA is taking direct final action to amend the National Volatile Organic Compound Emission Standards for Aerosol Coatings final rule, which is a rule that establishes national reactivity-based emission standards for the aerosol coatings category (aerosol spray paints) under the Clean Air Act, published elsewhere in the Federal Register. This direct final action adds three compounds:......

  4. 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. PMID:22685100

  5. Compound-Specific Isotope Analysis of Volatile Organosulfur Compounds from Cariaco Basin

    NASA Astrophysics Data System (ADS)

    Raven, M. R.; Sessions, A. L.; Adkins, J. F.; Subhas, A.

    2011-12-01

    Sulfur isotopes have the potential to elucidate important transformations of organic matter in sulfur-rich environments, particularly marine sediments. To date, analytical limitations have restricted such studies either to bulk measurements, which necessarily ignore the diverse constituents of organic matter, or to the analysis of compounds that can be isolated in significant (mg) quantities. By coupling a gas chromatograph to a multicollector ICPMS, we are now able to measure the sulfur isotopic compositions of individual organosulfur compounds in complex environmental samples. Lipids were extracted from a Cariaco Basin sediment core representing approximately 11 kyr of sediment deposition and diagenesis under consistently euxinic conditions. After separation by column chromatography, the nonpolar lipid fractions were found to contain sulfur-bearing species with δ34SCDT values ranging from -11% to +17.5% based on calibration with an internal (SF6) standard. This range of values confirms previous speculation that multiple pathways for organic matter sulfurization must exist in marine sediments, and provides the opportunity to track precursor-product relationships as diagenesis progresses down-core. Repeat measurements consistently demonstrate relative standard deviations for δ34S of between 0.2% and 0.4% for peaks containing only a few pmol S. The relative abundances and isotopic compositions of individual compounds are observed to vary with depth and age. Additional data are being collected and will be presented at the meeting.

  6. Changes in Volatile Compounds during Aging of Sweet Fennel Fruits-Comparison of Hydrodistillation and Static Headspace Sampling Methods.

    PubMed

    Najdoska-Bogdanov, Mence; Bogdanov, Jane B; Stefova, Marina

    2016-03-01

    Two extraction methods for subsequent gas chromatographic (GC) determination of volatiles from freshly harvested and aged fennel fruit samples (Foeniculum vulgare Mill.,ssp. vulgare var. dulce) have been compared. Hydrodistillation followed by GC-FID and GC-MS analysis was used as a standard method for essential oil characterization, while static headspace followed by GC (SHS-GC-FID) was used as a comparative method for determination of volatile components. As the fennel fruit ages, there is a gradual loss of the volatile components as indicated by the lower yield of essential oil and lower content of volatiles, as indicated by the alternative SHS-GC-FID analysis. Slight differences observed for the main components (trans-anethole, estragole, fenchone, and limonene) using the two methods are negligible, indicating that these volatiles did not undergo chemical transformation during the sample preparation procedures. A difference in anisaldehyde content was observed when the composition of the hydrodistilled essential oil was compared with the SHS-GC-FIDanalysis of volatiles and explanation for the variation of anisaldehyde content and the origin of other compounds was suggested. Comparison of the obtained results showed that limonene oxides, carvone and carveolare detectable in SHS-GC-FID analysis of the aged fennel fruits, while in hydrodistilled samples analyzed by GC-FID they were not present. Another observed difference was the appearance of products in significant amounts with higher retention times than trans-anethole, namely threo- and erythro-anethole β-hydroxymethylether and anethole glycol that are not detectable in the essential oil obtained by hydrodistillation. So, the relative abundance of the major components is comparable between these two methods for fennel seed up to 3 years from harvest and they can be used interchangeably depending on the purpose and amount of material. Furthermore, SHS-GC-FID can be used for assessment of maximum storage time

  7. Temperature-dependent release of volatile organic compounds of eucalypts by direct analysis in real time (DART) mass spectrometry.

    PubMed

    Maleknia, Simin D; Vail, Teresa M; Cody, Robert B; Sparkman, David O; Bell, Tina L; Adams, Mark A

    2009-08-01

    A method is described for the rapid identification of biogenic, volatile organic compounds (VOCs) emitted by plants, including the analysis of the temperature dependence of those emissions. Direct analysis in real time (DART) enabled ionization of VOCs from stem and leaf of several eucalyptus species including E. cinerea, E. citriodora, E. nicholii and E. sideroxylon. Plant tissues were placed directly in the gap between the DART ionization source skimmer and the capillary inlet of the time-of-flight (TOF) mass spectrometer. Temperature-dependent emission of VOCs was achieved by adjusting the temperature of the helium gas into the DART ionization source at 50, 100, 200 and 300 degrees C, which enabled direct evaporation of compounds, up to the onset of pyrolysis of plant fibres (i.e. cellulose and lignin). Accurate mass measurements facilitated by TOF mass spectrometry provided elemental compositions for the VOCs. A wide range of compounds was detected from simple organic compounds (i.e. methanol and acetone) to a series of monoterpenes (i.e. pinene, camphene, cymene, eucalyptol) common to many plant species, as well as several less abundant sesquiterpenes and flavonoids (i.e. naringenin, spathulenol, eucalyptin) with antioxidant and antimicrobial properties. The leaf and stem tissues for all four eucalypt species showed similar compounds. The relative abundances of methanol and ethanol were greater in stem wood than in leaf tissue suggesting that DART could be used to investigate the tissue-specific transport and emissions of VOCs. PMID:19551840

  8. Atmospheric PM and volatile organic compounds released from Mediterranean shrubland wildfires

    NASA Astrophysics Data System (ADS)

    Garcia-Hurtado, Elisa; Pey, Jorge; Borrás, Esther; Sánchez, Pilar; Vera, Teresa; Carratalá, Adoración; Alastuey, Andrés; Querol, Xavier; Vallejo, V. Ramon

    2014-06-01

    Wildfires produce a significant release of gases and particles affecting climate and air quality. In the Mediterranean region, shrublands significantly contribute to burned areas and may show specific emission profiles. Our objective was to depict and quantify the primary-derived aerosols and precursors of secondary particulate species released during shrubland experimental fires, in which fire-line intensity values were equivalent to those of moderate shrubland wildfires, by using a number of different methodologies for the characterization of organic and inorganic compounds in both gas-phase and particulate-phase. Emissions of PM mass, particle number concentrations and organic and inorganic PMx components during flaming and smouldering phases were characterized in a field shrubland fire experiment. Our results revealed a clear prevalence of K+ and SO42- as inorganic ions released during the flaming-smouldering processes, accounting for 68-80% of the inorganic soluble fraction. During the residual-smouldering phases, in addition to K+ and SO42-, Ca2+ was found in significant amounts probably due the predominance of re-suspension processes (ashes and soil dust) over other emission sources during this stage. Concerning organic markers, the chromatograms were dominated by phenols, n-alkanals and n-alkanones, as well as by alcohol biomarkers in all the PMx fractions investigated. Levoglucosan was the most abundant degradation compound with maximum emission factors between 182 and 261 mg kg-1 in PM2.5 and PM10 respectively. However, levoglucosan was also observed in significant amounts in the gas-phase. The most representative organic volatile constituents in the smoke samples were alcohols, carbonyls, acids, monocyclic and bicyclic arenes, isoprenoids and alkanes compounds. The emission factors obtained in this study may contribute to the validation and improvement of national and international emission inventories of this intricate and diffuse emission source.

  9. On the use of plant emitted volatile organic compounds for atmospheric chemistry simulation experiments

    NASA Astrophysics Data System (ADS)

    Kiendler-Scharr, A.; Hohaus, T.; Yu, Z.; Tillmann, R.; Kuhn, U.; Andres, S.; Kaminski, M.; Wegener, R.; Novelli, A.; Fuchs, H.; Wahner, A.

    2015-12-01

    Biogenic volatile organic compounds (BVOC) contribute to about 90% of the emitted VOC globally with isoprene being one of the most abundant BVOC (Guenther 2002). Intensive efforts in studying and understanding the impact of BVOC on atmospheric chemistry were undertaken in the recent years. However many uncertainties remain, e.g. field studies have shown that in wooded areas measured OH reactivity can often not be explained by measured BVOC and their oxidation products (e.g. Noelscher et al. 2012). This discrepancy may be explained by either a lack of understanding of BVOC sources or insufficient understanding of BVOC oxidation mechanisms. Plants emit a complex VOC mixture containing likely many compounds which have not yet been measured or identified (Goldstein and Galbally 2007). A lack of understanding BVOC sources limits bottom-up estimates of secondary products of BVOC oxidation such as SOA. Similarly, the widespread oversimplification of atmospheric chemistry in simulation experiments, using single compound or simple BVOC mixtures to study atmospheric chemistry processes limit our ability to assess air quality and climate impacts of BVOC. We will present applications of the new extension PLUS (PLant chamber Unit for Simulation) to our atmosphere simulation chamber SAPHIR. PLUS is used to produce representative BVOC mixtures from direct plant emissions. We will report on the performance and characterization of the newly developed chamber. As an exemplary application, trees typical of a Boreal forest environment were used to compare OH reactivity as directly measured by LIF to the OH reactivity calculated from BVOC measured by GC-MS and PTRMS. The comparison was performed for both, primary emissions of trees without any influence of oxidizing agents and using different oxidation schemes. For the monoterpene emitters investigated here, we show that discrepancies between measured and calculated total OH reactivity increase with increasing degree of oxidation

  10. Consumer palatability scores, sensory descriptive attributes, and volatile compounds of grilled beef steaks from three USDA Quality Grades.

    PubMed

    Legako, J F; Dinh, T T N; Miller, M F; Adhikari, K; Brooks, J C

    2016-02-01

    Consumer palatability scores, sensory descriptive attributes, and volatile compounds were assessed for beef Longissimus lumborum steaks of USDA Prime, Low Choice, and Standard grades. Overall and flavor liking was greater (P<0.05) for Prime and Low Choice. Initial flavor impact and fat-like attributes were greater (P<0.05) among Prime and Low Choice. Prime had greater (P<0.05) brown/roasted, beef identity, overall sweetness, and umami. Cardboard was greater (P<0.05) in Standard. Volatile compounds representing flavor development pathways were varied with quality grade. Standard had greater (P<0.05) abundances of n-aldehydes. Phenylacetaldehyde was greater (P<0.05) in Prime and Low Choice. Both 2,3-butanedione and 3-hydroxy-2-butanone were greatest (P<0.05) in Prime. Overall liking was positively correlated with many descriptive attributes, 3-hydroxy-2-butanone, and phenylacetaldehyde, and negatively correlated with cardboard, green, and n-aldehydes. While the measured attributes and volatiles may not be causative of flavor, this data indicates potential for prediction of flavor through their measurement. PMID:26555563

  11. Environmental Aspects of Two Volatile Organic Compound Groundwater Treatment Designs at the Rocky Flats Site - 13135

    SciTech Connect

    Michalski, Casey C.; DiSalvo, Rick; Boylan, John

    2013-07-01

    DOE's Rocky Flats Site in Colorado is a former nuclear weapons production facility that began operations in the early 1950's. Because of releases of hazardous substances to the environment, the federally owned property and adjacent offsite areas were placed on the CERCLA National Priorities List in 1989. The final remedy was selected in 2006. Engineered components of the remedy include four groundwater treatment systems that were installed before closure as CERCLA-accelerated actions. Two of the systems, the Mound Site Plume Treatment System and the East Trenches Plume Treatment System, remove low levels of volatile organic compounds using zero-valent iron media, thereby reducing the loading of volatile organic compounds in surface water resulting from the groundwater pathway. However, the zero-valent iron treatment does not reliably reduce all volatile organic compounds to consistently meet water quality goals. While adding additional zero-valent iron media capacity could improve volatile organic compound removal capability, installation of a solar powered air-stripper has proven an effective treatment optimization in further reducing volatile organic compound concentrations. A comparison of the air stripper to the alternative of adding additional zero-valent iron capacity to improve Mound Site Plume Treatment System and East Trenches Plume Treatment System treatment based on several key sustainable remediation aspects indicates the air stripper is also more 'environmentally friendly'. These key aspects include air pollutant emissions, water quality, waste management, transportation, and costs. (authors)

  12. Potential Signatures of Semi-volatile Compounds Associated With Nuclear Processing

    SciTech Connect

    Probasco, Kathleen M.; Birnbaum, Jerome C.; Maughan, A. D.

    2002-06-01

    Semi-volatile chemicals associated with nuclear processes (e.g., the reprocessing of uranium to produce plutonium for nuclear weapons, or the separation of actinides from processing waste streams), can provide sticky residues or signatures that will attach to piping, ducting, soil, water, or other surface media. Volatile compounds, that are more suitable for electro-optical sensing, have been well studied. However, the semi-volatile compounds have not been well documented or studied. A majority of these semi-volatile chemicals are more robust than typical gaseous or liquid chemicals and can have lifetimes of several weeks, months, or years in the environment. However, large data gaps exist concerning these potential signature compounds and more research is needed to fill these data gaps so that important signature information is not overlooked or discarded. This report investigates key semi-volatile compounds associated with nuclear separations, identifies available chemical and physical properties, and discusses the degradation products that would result from hydrolysis, radiolysis and oxidation reactions on these compounds.

  13. Effect of toasting on non-volatile and volatile vine-shoots low molecular weight phenolic compounds.

    PubMed

    Sánchez-Gómez, R; Zalacain, A; Alonso, G L; Salinas, M R

    2016-08-01

    Low molecular weight phenolic compounds (LMWPC), including non-volatile and volatile, of Airén and Moscatel vine-shoot cultivars waste submitted to different toasting conditions (light, 180°/15min; medium, 180°/30min; high 180°/45min) were studied in order to exploit them with oenological purposes. The LMWPC differences were mainly due to the toasting times rather than vine-shoot variety. In non-volatile LMWPC fraction, flavanols and almost all phenolic acids decreased by toasting. The presence of trans-resveratrol has a special relevance at light toasting: 14 times more concentrated in Airén and 6 times in Moscatel vine-shoots, than their respective non-toasted samples. The volatile LMWPC showed a significant increment with toasting, being vanillin the one with the highest difference respect to non-toasted samples at high conditions: more than 15 times in Airén and 11 in Moscatel. Although toasting reduced some LMWPC, particular characteristics of these vine-shoots must be taken into account when considering its future use. PMID:26988529

  14. AN IMPROVED METHOD FOR THE BIOLOGICAL MONITORING OF VOLATILE COMPOUNDS

    SciTech Connect

    Thrall, Karla D.

    2006-01-01

    Exposure assessment is a critical component in estimating health risk. The analysis of exhaled breath offers an ideal non-invasive matrix for measuring volatile biomarkers associated with the absorption, distribution, metabolism and elimination of chemicals under a variety of environmental conditions. A real-time, field-portable system was developed to directly analyze undiluted exhaled air from experimental animals and humans. The exhaled breath data is evaluated using a physiologically based pharmacokinetic model to estimate total exposure, internal target tissue dosimetry, and to describe kinetic changes. To date, the system has been used to conduct occupational exposure assessments and dermal bioavailability studies.

  15. PLANT VOLATILES. Biosynthesis of monoterpene scent compounds in roses.

    PubMed

    Magnard, Jean-Louis; Roccia, Aymeric; Caissard, Jean-Claude; Vergne, Philippe; Sun, Pulu; Hecquet, Romain; Dubois, Annick; Hibrand-Saint Oyant, Laurence; Jullien, Frédéric; Nicolè, Florence; Raymond, Olivier; Huguet, Stéphanie; Baltenweck, Raymonde; Meyer, Sophie; Claudel, Patricia; Jeauffre, Julien; Rohmer, Michel; Foucher, Fabrice; Hugueney, Philippe; Bendahmane, Mohammed; Baudino, Sylvie

    2015-07-01

    The scent of roses (Rosa x hybrida) is composed of hundreds of volatile molecules. Monoterpenes represent up to 70% percent of the scent content in some cultivars, such as the Papa Meilland rose. Monoterpene biosynthesis in plants relies on plastid-localized terpene synthases. Combining transcriptomic and genetic approaches, we show that the Nudix hydrolase RhNUDX1, localized in the cytoplasm, is part of a pathway for the biosynthesis of free monoterpene alcohols that contribute to fragrance in roses. The RhNUDX1 protein shows geranyl diphosphate diphosphohydrolase activity in vitro and supports geraniol biosynthesis in planta. PMID:26138978

  16. Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system.

    PubMed

    Cayot, Nathalie; Lafarge, Céline; Bou-Maroun, Elias; Cayot, Philippe

    2016-07-22

    Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds with different hydrophobicity are used. High extraction yields were positively correlated with high boiling points and high Log Kow values of volatile compounds. Mixtures of solvents such as azeotrope propan-2-one/cyclopentane, azeotrope ethyl acetate/ethanol, and mixture ethyl acetate/ethanol (3:1, v/v) gave higher extraction yields than those obtained with dichloromethane. PMID:27320380

  17. Snowpack concentrations and estimated fluxes of volatile organic compounds in a boreal forest

    NASA Astrophysics Data System (ADS)

    Aaltonen, H.; Pumpanen, J.; Hakola, H.; Vesala, T.; Rasmus, S.; Bäck, J.

    2012-01-01

    Soil forms an important source for volatile organic compounds (VOCs), but in boreal forests these fluxes and their seasonal variations have not been characterized in detail, especially wintertime fluxes, which are almost completely unstudied. In this study, we measured the VOC concentrations inside a snowpack in a boreal Scots pine (Pinus sylvestris L.) forest in southern Finland, using adsorbent tubes and air samplers installed permanently in the snow profile. Based on the VOC concentrations at three heights inside the snowpack, we estimated the fluxes of these gases. We measured 20 VOCs from the snowpack, monoterpenes being the most abundant group with concentrations varying from 0.11 to 16 μg m-3. Sesquiterpenes and oxygen-containing monoterpenes were also detected. Inside the pristine snowpack, the concentrations of terpenoids decreased from the soil surface towards the snow surface, suggesting soil as being the source for terpenoids. Forest damages resulting from heavy snow loading during the measurement period increased the terpenoid concentrations dramatically, especially in the upper part of the snowpack. The results show that soil processes are also active and efficient VOC sources during winter and that natural or human disturbance can increase forest floor VOC concentrations substantially. Our results stress the importance of soil as a source of VOCs during the season when other biological sources, basically plants, have lower activity.

  18. Snowpack concentrations and estimated fluxes of volatile organic compounds in a boreal forest

    NASA Astrophysics Data System (ADS)

    Aaltonen, H.; Pumpanen, J.; Hakola, H.; Vesala, T.; Rasmus, S.; Bäck, J.

    2012-06-01

    Soil provides an important source of volatile organic compounds (VOCs) to atmosphere, but in boreal forests these fluxes and their seasonal variations have not been characterized in detail. Especially wintertime fluxes are almost completely unstudied. In this study, we measured the VOC concentrations inside the snowpack in a boreal Scots pine (Pinus sylvestris L.) forest in southern Finland, using adsorbent tubes and air samplers installed permanently in the snow profile. Based on the VOC concentrations at three heights inside the snowpack, we estimated the fluxes of these gases. We measured 20 VOCs from the snowpack, monoterpenes being the most abundant group with concentrations varying from 0.11 to 16 μg m-3. Sesquiterpenes and oxygen-containing monoterpenes were also detected. Inside the pristine snowpack, the concentrations of terpenoids decreased from soil surface towards the surface of the snow, suggesting soil as the source for terpenoids. Forest damages (i.e. broken treetops and branches, fallen trees) resulting from heavy snow loading during the measurement period increased the terpenoid concentrations dramatically, especially in the upper part of the snowpack. The results show that soil processes are active and efficient VOC sources also during winter, and that natural or human disturbance can increase forest floor VOC concentrations substantially. Our results stress the importance of soil as a source of VOCs during the season when other biological sources, such as plants, have lower activity.

  19. Ambient levels of volatile organic compounds in the vicinity of petrochemical industrial area of Yokohama, Japan

    PubMed Central

    Hanai, Yoshimichi; Masunaga, Shigeki

    2009-01-01

    Urban ambient air concentrations of 39 aromatic (including benzene, toluene, and xylenes) and aliphatic volatile organic compounds (VOCs) were measured in Yokohama city, Japan. Yokohama city was selected as a case study to assess the amount of VOC released from Industrial area to characterize the ambient air quality with respect to VOC as well as to know the impact of petrochemical storage facilities on local air quality. For this purpose, ambient air samples were collected (from June 2007 to November 2008) at six selected locations which are designated as industrial, residential, or commercial areas. To find out the diurnal variations of VOC, hourly nighttime sampling was carried out for three nights at one of the industrial locations (Shiohama). Samples were analyzed using gas chromatographic system (GC-FID). Results show strong variation between day and nighttime concentrations and among the seasons. Aliphatic fractions were most abundant, suggesting petrochemical storage facilities as the major source of atmospheric hydrocarbons. High concentrations of benzene, toluene, ethyl benzene, and xylene (BTEX) were observed at industrial locations. BTEX showed strong diurnal variation which is attributed to change in meteorology. During our campaign, low ambient VOC concentrations were observed at the residential site. PMID:20495606

  20. Assessing California groundwater susceptibility using trace concentrations of halogenated volatile organic compounds

    USGS Publications Warehouse

    Deeds, Daniel A.; Kulongoski, Justin T.; Belitz, Kenneth

    2012-01-01

    Twenty-four halogenated volatile organic compounds (hVOCs) and SF6 were measured in groundwater samples collected from 312 wells across California at concentrations as low as 10–12 grams per kilogram groundwater. The hVOCs detected are predominately anthropogenic (i.e., “ahVOCs”) and as such their distribution delineates where groundwaters are impacted and susceptible to human activity. ahVOC detections were broadly consistent with air-saturated water concentrations in equilibrium with a combination of industrial-era global and regional hVOC atmospheric abundances. However, detection of ahVOCs in nearly all of the samples collected, including ancient groundwaters, suggests the presence of a sampling or analytical artifact that confounds interpretation of the very-low concentration ahVOC data. To increase our confidence in ahVOC detections we establish screening levels based on ahVOC concentrations in deep wells drawing ancient groundwater in Owens Valley. Concentrations of ahVOCs below the Owens Valley screening levels account for a large number of the detections in prenuclear groundwater across California without significant loss of ahVOC detections in shallow, recently recharged groundwaters. Over 80% of the groundwaters in this study contain at least one ahVOC after screening, indicating that the footprint of human industry is nearly ubiquitous and that most California groundwaters are vulnerable to contamination from land-surface activities.

  1. Assessing California groundwater susceptibility using trace concentrations of halogenated volatile organic compounds.

    PubMed

    Deeds, Daniel A; Kulongoski, Justin T; Belitz, Kenneth

    2012-12-18

    Twenty-four halogenated volatile organic compounds (hVOCs) and SF₆ were measured in groundwater samples collected from 312 wells across California at concentrations as low as 10⁻¹² grams per kilogram groundwater. The hVOCs detected are predominately anthropogenic (i.e., "ahVOCs") and as such their distribution delineates where groundwaters are impacted and susceptible to human activity. ahVOC detections were broadly consistent with air-saturated water concentrations in equilibrium with a combination of industrial-era global and regional hVOC atmospheric abundances. However, detection of ahVOCs in nearly all of the samples collected, including ancient groundwaters, suggests the presence of a sampling or analytical artifact that confounds interpretation of the very-low concentration ahVOC data. To increase our confidence in ahVOC detections we establish screening levels based on ahVOC concentrations in deep wells drawing ancient groundwater in Owens Valley. Concentrations of ahVOCs below the Owens Valley screening levels account for a large number of the detections in prenuclear groundwater across California without significant loss of ahVOC detections in shallow, recently recharged groundwaters. Over 80% of the groundwaters in this study contain at least one ahVOC after screening, indicating that the footprint of human industry is nearly ubiquitous and that most California groundwaters are vulnerable to contamination from land-surface activities. PMID:23153122

  2. Characteristics of volatile organic compounds from motorcycle exhaust emission during real-world driving

    NASA Astrophysics Data System (ADS)

    Tsai, Jiun-Horng; Huang, Pei-Hsiu; Chiang, Hung-Lung

    2014-12-01

    The number of motorcycles has increased significantly in Asia, Africa, Latin American and Europe in recent years due to their reasonable price, high mobility and low fuel consumption. However, motorcycles can emit significant amounts of air pollutants; therefore, the emission characteristics of motorcycles are an important consideration for the implementation of control measures for motorcycles in urban areas. Results of this study indicate that most volatile organic compound (VOC) emission factors were in the range of several decades mg/km during on-road driving. Toluene, isopentane, 1,2,4-trimethylbenzene, m,p-xylene, and o-xylene were the most abundant VOCs in motorcycle exhaust, with emission factors of hundreds mg/km. Motorcycle exhaust was 15.4 mg/km for 15 carbonyl species. Acetaldehyde, acetone, formaldehyde and benzaldehyde were the major carbonyl species, and their emission factors ranged from 1.4 to 3.5 mg/km 1,2,4-trimethylbenzene, m,p-xylene, 1-butene, toluene, o-xylene, 1,2,3-trimethylbenzene, propene, 1,3,5-trimethylbenzene, isoprene, m-diethylbenzene, and m-ethyltoluene were the main ozone formation potential (OFP) species, and their OFP was 200 mg-O3/km or higher.

  3. Effects of nonmethane volatile organic compounds on microbial community of methanotrophic biofilter.

    PubMed

    Kim, Tae Gwan; Lee, Eun-Hee; Cho, Kyung-Suk

    2013-07-01

    Effects of nonmethane volatile organic compounds (NMVOCs) on methanotrophic biofilter were investigated. Laboratory-scale biofilters packed with pumice and granular-activated carbon (10:1, w/w) were operated with CH4 and NMVOCs including dimethyl sulfide (DMS) and benzene/toluene (B/T). DMS alone exhibited a positive effect on the methanotrophic performance; however, the coexistence of B/T removed this effect. B/T alone exerted no effect on the performance. Pyrosequencing and quantitative PCR revealed that the NMVOCs strongly influenced the bacterial and methanotrophic communities but not the population density of methanotrophs. DMS alone diversified and changed both bacterial and methantrophic communities, but its effects were nullified by the presence of B/T. Canonical correspondence analysis revealed significant correlations between the NMVOCs and community composition and significant interaction between DMS and B/T. DMS did not affect the distribution of types I/II methanotrophs (60/40), while B/T increased the abundance of type I to 82 %. DMS and B/T favored the growth of the methanotrophic bacteria Methylosarcina and Methylomonas, respectively. These results suggest that NMVOCs can be a significant abiotic factor influencing methane biofiltration. PMID:23053093

  4. Characteristics and reactivity of volatile organic compounds from non-coal emission sources in China

    NASA Astrophysics Data System (ADS)

    He, Qiusheng; Yan, Yulong; Li, Hongyan; Zhang, Yiqiang; Chen, Laiguo; Wang, Yuhang

    2015-08-01

    Volatile organic compounds (VOCs) were sampled from non-coal emission sources including fuel refueling, solvent use, industrial and commercial activities in China, and 62 target species were determined by gas chromatography-mass selective detector (GC-MSD). Based on the results, source profiles were developed and discussed from the aspects of composition characteristics, potential tracers, BTEX (benzene, toluene, ethylbenzene and xylene) diagnostic ratios and chemical reactivity. Compared with vehicle exhausts and liquid fuels, the major components in refueling emissions of liquefied petroleum gas (LPG), gasoline and diesel were alkenes and alkanes. Oppositely, aromatics were the most abundant group in emissions from auto-painting, book binding and plastic producing. Three groups contributed nearly equally in printing and commercial cooking emissions. Acetone in medical producing, chloroform and tetrachloroethylene in wet- and dry-cleaning, as well as TEX in plastic producing etc. were good tracers for the respective sources. BTEX ratios showed that some but not all VOCs sources could be distinguished by B/T, B/E and B/X ratios, while T/E, T/X and E/X ratios were not suitable as diagnostic indicators of different sources. The following reactivity analysis indicated that emissions from gasoline refueling, commercial cooking, auto painting and plastic producing had high atmospheric reactivity, and should be controlled emphatically to prevent ozone pollution, especially when there were large amounts of emissions for them.

  5. Safety Evaluation of Osun River Water Containing Heavy Metals and Volatile Organic Compounds (VOCs) in Rats.

    PubMed

    Azeez, L; Salau, A K; Adewuyi, S O; Osineye, S O; Tijani, K O; Balogun, R O

    2015-01-01

    This study evaluated the pH, heavy metals and volatile organic compounds (VOCs) in Osun river water. It also evaluated its safety in rats. Heavy metals were determined by atomic absorption spectrophotometry (AAS) while VOCs were determined by gas chromatography coupled with flame ionization detector (GC-FID). Male and female rats were exposed to Osun river water for three weeks and then sacrificed. The abundance of heavy metals in Osun river followed the trend Pb > Cd > Zn > Fe > Cr > Cu while VOCs followed the trend benzene < ethylbenzene < toluene < xylene. The concentrations of Pb, Cd and benzene were higher than the permissible limits of Standards Organization of Nigeria (SON) and World Health Organization (WHO) respectively. Rats exposed to Osun river water for three weeks had increased WBC, thiobarbituric acid reactive substances (TBARS), serum proteins and serum aminotransferases. There were also significant decreases in HCT, PLT, liver aminotransferases and liver glutathione compared to the control. These results show that the pollutants in Osun river water are capable of inducing hematological imbalance and liver cell injury. The toxicity induced in blood was sex-dependent affecting female rats more than male rats. PMID:27506174

  6. Volatile organic compounds from Italian vegetation and their interaction with ozone.

    PubMed

    Calfapietra, Carlo; Fares, Silvano; Loreto, Francesco

    2009-05-01

    Volatile Organic Compounds (VOCs) emitted from vegetation (particularly isoprenoids) represent an important source of atmospheric hydrocarbons almost double the anthropogenic source. When biogenic VOC mix with NO(x) in the presence of UV radiation, ozone (O(3)) is formed. In Italy, optimal conditions for O(3) formation in terms of VOC/NO(x) ratios and abundance of UV radiation occur for long periods of the year. Moreover, Italian vegetation includes several species that are strong and evergreen isoprenoid emitters, and high temperatures for part of the year further stimulate these temperature-dependent emissions. We review emission of isoprenoids from Italian vegetation, current knowledge on the impact of rising O(3) levels on isoprenoid emission, and evidence showing that isoprenoids can increase both the O(3) flux to the plant and protection against oxidative stress because of their antioxidant functions. This trait not only influences plant tolerance to O(3) but also may substantially alter the flux of O(3) between atmosphere and biosphere. PMID:19019511

  7. Chemical indicators of sulfate sensitivity to nitrogen oxides and volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Stein, Ariel F.; Lamb, Dennis

    2002-10-01

    The formation of aerosol sulfate (SO42-) in eastern North America is chemically linked to the emissions of nitrogen oxides (NOx) and volatile organic compounds (VOC) through oxidation of the gaseous precursor, sulfur dioxide (SO2). The response of sulfate production to controls in NOx and VOC emissions depends, in part, on the resulting changes in oxidant levels and the competition that naturally exists between the gas- and aqueous-phase pathways for SO2 oxidation. We propose the use of a combination of concentrations of nitric acid, particulate nitrate, hydrogen peroxide, and ambient sulfate as a nondimensional indicator of the effectiveness of VOC or NOx controls in decreasing SO42- abundance. The concentrations of these indicator species were calculated from a series of photochemical model simulations with varying rates of NOx and VOC emissions using a three-dimensional Eulerian model (MODELS-3) that covers the northeastern United States. This study shows that ambient sulfate concentrations are likely to decrease more effectively as VOC emissions are reduced, when the nondimensional indicator is less than a certain threshold. However, a higher value of the indicator identifies a regime in which NOx emissions reductions are more effective for reducing sulfate than are VOC emissions. In addition, a description of the sulfate-formation pathways, along with a theoretical analysis of the transition between NOx- and VOC-sensitive regimes, provides a strong rationale for the use of the sulfate sensitivity indicator.

  8. Source location and characterization of volatile organic compound emissions at a petrochemical plant in Kaohsiung, Taiwan.

    PubMed

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

    2005-10-01

    This paper elucidated a novel approach to locating volatile organic compound (VOC) emission sources and characterizing their VOCs by database and contour plotting. The target of this survey was a petrochemical plant in Linyan, Kaohsiung County, Taiwan. Samples were taken with canisters from 25 sites inside this plant, twice per season, and analyzed by gas chromatography-mass spectrometry. The survey covered 1 whole year. By consolidated into a database, the data could be readily retrieved, statistically analyzed, and clearly presented in both table and graph forms. It followed from the cross-analysis of the database that the abundant types of VOCs were alkanes, alkenes/dienes, and aromatics, all of which accounted for 99% of total VOCs. By contour plotting, the emission sources for alkanes, aromatics, and alkenes/ dienes were successfully located. Through statistical analysis, the database could provide the range and 90% confidence interval of each species from each emission source. Both alkanes and alkene/dienes came from tank farm and naphtha cracking units and were mainly composed of C3-C5 members. Regarding aromatics, benzene, toluene, and xylenes were the primary species; they were emitted from tank farm, aromatic units, and xylene units. PMID:16295274

  9. Laboratory and field screening strategies for measuring volatile organic compounds in landfill gas

    SciTech Connect

    Emerson, C.W.

    1999-11-01

    Distinct patterns often exist in the presence and absence of hazardous contaminants in the environment. These patterns can be used to select efficient screening tools, or groups of compounds that provide the most information on overall occurrences of a larger target group of compounds. By using these screens to indicate whether a sample is contaminated with detectable amounts of the compounds of interest, attention can be focused on those samples considered most likely to contain measurable concentrations of targeted compounds. The cost savings that result from eliminating samples that are most likely uncontaminated can be applied to obtaining additional samples that more accurately characterize the spatial or temporal variability of the environmental problem. In a retrospective application of screening techniques to the State of California's database of volatile organic compounds in landfill gas, two laboratory screening compounds, perchloroethylene and methylene chloride, represent over 95% of the total number of positive detections of a target group of 10 volatile organic compounds. Benzene and vinyl chloride, two field screening compounds that were selected using the characteristics of commercially available colorimetric detector tubes, recorded 74% of the total contaminant detections and a 52% savings in analytical costs as compared to an exhaustive analysis of every sample for all 10 volatile organic compounds. The number of detections recorded could have been improved if more sensitive and less selective field screening devices were available.

  10. Fluxes of biogenic volatile organic compounds measured and modelled above a Norway spruce forest

    NASA Astrophysics Data System (ADS)

    Juráň, Stanislav; Fares, Silvano; Pallozzi, Emanuele; Guidolotti, Gabriele; Savi, Flavia; Alivernini, Alessandro; Calfapietra, Carlo; Večeřová, Kristýna; Křůmal, Kamil; Večeřa, Zbyněk; Cudlín, Pavel; Urban, Otmar

    2016-04-01

    Fluxes of biogenic volatile organic compounds (BVOCs) were investigated at Norway spruce forest at Bílý Kříž in Beskydy Mountains of the Czech Republic during the summer 2014. A proton-transfer-reaction-time-of-flight mass spectrometer (PTR-TOF-MS, Ionicon Analytik, Austria) has been coupled with eddy-covariance system. Additionally, Inverse Lagrangian Transport Model has been used to derive fluxes from concentration gradient of various monoterpenes previously absorbed into n-heptane by wet effluent diffusion denuder with consequent quantification by gas chromatography with mass spectrometry detection. Modelled data cover each one day of three years with different climatic conditions and previous precipitation patterns. Model MEGAN was run to cover all dataset with monoterpene fluxes and measured basal emission factor. Highest fluxes measured by eddy-covariance were recorded during the noon hours, represented particularly by monoterpenes and isoprene. Inverse Lagrangian Transport Model suggests most abundant monoterpene fluxes being α- and β-pinene. Principal component analysis revealed dependencies of individual monoterpene fluxes on air temperature and particularly global radiation; however, these dependencies were monoterpene specific. Relationships of monoterpene fluxes with CO2 flux and relative air humidity were found to be negative. MEGAN model correlated to eddy-covariance PTR-TOF-MS measurement evince particular differences, which will be shown and discussed. Bi-directional fluxes of oxygenated short-chain volatiles (methanol, formaldehyde, acetone, acetaldehyde, formic acid, acetic acid, methyl vinyl ketone, methacrolein, and methyl ethyl ketone) were recorded by PTR-TOF-MS. Volatiles of anthropogenic origin as benzene and toluene were likely transported from the most benzene polluted region in Europe - Ostrava city and adjacent part of Poland around Katowice, where metallurgical and coal mining industries are located. Those were accumulated during

  11. Volatile compounds and bacterial community dynamics of chestnut-flour-based sourdoughs.

    PubMed

    Aponte, M; Boscaino, F; Sorrentino, A; Coppola, R; Masi, P; Romano, A

    2013-12-01

    The aims of this study were the monitoring of the microbial dynamics by means of a polyphasic approach based on conventional isolation techniques and PCR-DGGE-based methods in different chestnut-based sourdoughs and the evaluation of the impact of fermentation on volatile organic compounds formation during sourdoughs ripening. Members of the Lactobacillus plantarum group and Pediococcus pentosaceous dominated the sourdough ecosystems. Nevertheless, RAPD-PCR allowed recording a relevant genotypic biodiversity among strains coming from gluten-free flour combinations. Volatile compounds were characterised by GC/MS. A total of 59 volatile compounds were identified, mainly alcohols, esters, acids, aldehydes and ketones. Principal component analysis of samples at the beginning and at the end of ripening offered a good separation of the samples and highlighted the effect of fermentation on the sensorial profile. PMID:23870973

  12. Analyzing Strawberry Spoilage via its Volatile Compounds Using Longpath Fourier Transform Infrared Spectroscopy

    PubMed Central

    Dong, Daming; Zhao, Chunjiang; Zheng, Wengang; Wang, Wenzhong; Zhao, Xiande; Jiao, Leizi

    2013-01-01

    The volatile compounds from fruits vary based on the spoilage stage. We used FTIR spectroscopy to analyze and to attempt to identify the spoilage process of strawberries. To enhance the sensitivity of the measuring system, we increased the optical pathlength by using multi-reflecting mirrors. The volatile compounds that were vaporized from strawberries in different spoilage stages were tested. We analyzed the spectra and found that the concentrations of esters, alcohols, ethylene, and similar compounds changed with deterioration. The change patterns of the infrared spectra for the volatiles were further examined using 2D correlation spectroscopy. We analyzed the spectral data using PCA and were able to distinguish the fresh, slightly spoiled strawberries from the seriously spoiled strawberries. This study demonstrates that FTIR is an effective tool for monitoring strawberry spoilage and for providing status alerts. PMID:24002611

  13. Student's exposure to volatile organic compounds while commuting by motorcycle and bus in Taipei City

    SciTech Connect

    Chan, C.C.; Lin, S.H.; Her, G.R. )

    1993-09-01

    This study examined student's exposure to volatile organic compounds (VOCs) while commuting by bus and motorcycle in Taipei, Taiwan in the winter of 1992. A total of 19 target C5-C10 VOCs on three most frequently used commuting routes were collected on Tenax-GC adsorbent tubes. The VOCs were desorbed by thermal desorption method and analyzed by GC-MS. The most abundant VOC exposure experienced by commuters was to toluene. Several alkylated benzenes, such as propyl benzenes, ethyl-methyl-benzenes and trimethyl-benzenes, were relatively abundant on the roads in Taipei. The mean benzene concentration measured in buses was 173 micrograms/m3 and motorcycles. On the average, the commuters in Taipei experienced about three to eight times higher VOC concentrations than the commuters in Los Angeles, California. Higher VOC concentrations were measured on motorcycles than in buses. The VOC concentrations were not significantly different between morning and afternoon commutes, nor among the three commuting routes. VOC concentrations measured in classroom at three schools in downtown Taipei did not vary significantly on each sampling day. However, at each school the in-classroom VOC concentrations varied significantly over the six consecutive sampling days. The VOC concentrations measured on the roads were about five times higher than those measured in the school classrooms in the city. Moderate to high correlations were found among most of the measurements of the 19 VOCs. The survey questionnaire indicated that daily commuting time ranged from 45 minutes for elementary school students to 95 minutes for vocational school students.

  14. Characteristics of Ambient Volatile Organic Compounds (VOCs) Measured in Shanghai, China

    PubMed Central

    Cai, Chang-Jie; Geng, Fu-Hai; Tie, Xue-Xi; Yu, Qiong; Peng, Li; Zhou, Guang-Qiang

    2010-01-01

    To better understand the characteristics of ambient abundance of volatile organic compounds (VOCs) in Shanghai, one of the biggest metropolis of China, VOCs were measured with a gas chromatography system equipped with a mass-selective detector (GC/MSD) from July 2006 to February 2010. An intensive measurement campaign was conducted (eight samples per day with a 3 hour interval) during May 2009. The comparison of ambient VOCs collected in different regions of Shanghai shows that the concentrations are slightly higher in the busy commercial area (28.9 ppbv at Xujiaui) than in the urban administrative area (24.3 ppbv at Pudong). However, during the intensive measurement period, the concentrations in the large steel industrial area (28.7 ppbv at Baoshan) were much higher than in the urban administrative area (18 ppbv at Pudong), especially for alkanes, alkenes, and toluene. The seasonal variations of ambient VOC concentrations measured at the Xujiahui sampling site indicate that the VOC concentrations are significantly affected by meteorological conditions (such as wind direction and precipitation). In addition, although alkanes are the most abundant VOCs at the Xujiahui measurement site, the most important VOCs contributing to ozone formation potential (OFP) are aromatics, accounting for 57% of the total OFP. The diurnal variations of VOC concentrations show that VOC concentrations are higher on weekdays than in weekends at the Xujiahui sampling site, suggesting that traffic condition and human activities have important impacts on VOC emissions in Shanghai. The evidence also shows that the major sources of isoprene are mainly resulted from gasoline evaporation at a particular time (06:00–09:00) in the busy commercial area. The results gained from this study provide useful information for better understanding the characteristics of ambient VOCs and the sources of VOCs in Shanghai. PMID:22163629

  15. Analysis of volatile compounds responsible for kiwifruit aroma by desiccated headspace gas chromatography-mass spectrometry.

    PubMed

    Zhang, Chun-Yun; Zhang, Qiong; Zhong, Cai-Hong; Guo, Ming-Quan

    2016-04-01

    A new method for desiccated headspace (DHS) sampling of aqueous sample to GC-MS for the analysis of volatile compounds responsible for kiwifruit aroma in different kiwifruit cultivars has been developed based on the complete hydrate formation between the sample solvent (water) with anhydrous salt (calcium chloride) at an elevated temperature (above the boiling point of the aqueous sample) in a non-contact format, which overcame the water-effect challenge to directly introduce aqueous sample into GC-MS analysis. By means of DHS, the volatile compounds in three different kiwifruit cultivars were analyzed and compared under the optimized operating conditions, mainly time and temperature for headspace equilibration, column temperature program for GC-MS measurement. As a result, 20 peaks of volatile compounds responsible for kiwifruit aroma were detected and remarkable differences were found in the relative contents of three major volatile compounds among the three different kiwifruit cultivars, i.e., acetaldehyde, ethanol and furfural. The DHS sampling technique used in the present method can make the GC-MS analysis of volatile compounds in the aqueous sample within complex matrix possible without contaminating the GC-MS instrument. In terms of the analysis of volatile compounds in kiwifruit, the present method enabled a direct measurement on the filtrate of the aqueous kiwifruit pulp, without intermediate trap phase for the extraction of analytes, which will be more reliable and simpler as compared with any other headspace method in use. Thus, DHS coupled with GC-MS will be a new valuable tool available for the kiwifruit related research and organoleptic quality control. PMID:26922094

  16. Detection of volatile organic compounds indicative of human presence in the air.

    PubMed

    Kwak, Jae; Geier, Brian A; Fan, Maomian; Gogate, Sanjay A; Rinehardt, Sage A; Watts, Brandy S; Grigsby, Claude C; Ott, Darrin K

    2015-07-01

    Volatile organic compounds were collected and analyzed from a variety of indoor and outdoor air samples to test whether human-derived compounds can be readily detected in the air and if they can be associated with human occupancy or presence. Compounds were captured with thermal desorption tubes and then analyzed by gas chromatography with mass spectrometry. Isoprene, a major volatile organic compound in exhaled breath, was shown to be the best indicator of human presence. Acetone, another major breath-borne compound, was higher in unoccupied or minimally occupied areas than in human-occupied areas, indicating that its majority may be derived from exogenous sources. The association of endogenous skin-derived compounds with human occupancy was not significant. In contrast, numerous compounds that are found in foods and consumer products were detected at elevated levels in the occupied areas. Our results revealed that isoprene and many exogenous volatile organic compounds consumed by humans are emitted at levels sufficient for detection in the air, which may be indicative of human presence. PMID:25944350

  17. Thermal engine driven heat pump for recovery of volatile organic compounds

    DOEpatents

    Drake, Richard L.

    1991-01-01

    The present invention relates to a method and apparatus for separating volatile organic compounds from a stream of process gas. An internal combustion engine drives a plurality of refrigeration systems, an electrical generator and an air compressor. The exhaust of the internal combustion engine drives an inert gas subsystem and a heater for the gas. A water jacket captures waste heat from the internal combustion engine and drives a second heater for the gas and possibly an additional refrigeration system for the supply of chilled water. The refrigeration systems mechanically driven by the internal combustion engine effect the precipitation of volatile organic compounds from the stream of gas.

  18. Influence of pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt.

    PubMed

    Akbaridoust, Ghazal; Plozza, Tim; Trenerry, V Craige; Wales, William J; Auldist, Martin J; Ajlouni, Said

    2015-08-01

    The influence of different pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt was studied. Pasture is the main source of nutrients for dairy cows in many parts of the world, including southeast Australia. Milk and milk products produced in these systems are known to contain a number of compounds with positive effects on human health. In the current study, 260 cows were fed supplementary grain and forage according to one of 3 different systems; Control (a traditional pasture based diet offered to the cows during milking and in paddock), PMR1 (a partial mixed ration which contained the same supplement as Control but was offered to the cows as a partial mixed ration on a feedpad), PMR 2 (a differently formulated partial mixed ration compared to Control and PMR1 which was offered to the cows on a feedpad). Most of the yoghurt fatty acids were influenced by feeding systems; however, those effects were minor on organic acids. The differences in feeding systems did not lead to the formation of different volatile organic flavour compounds in yoghurt. Yet, it did influence the relative abundance of these components. PMID:26143651

  19. Solid-phase microextraction and gas chromatography-mass spectrometry of volatile compounds from avocado puree after microwave processing.

    PubMed

    López, Mercedes G; Guzmán, G R; Dorantes, A L

    2004-05-14

    Microwave processing offers an alternative to blanch fruits and vegetables, since the application of high temperature and short time often results in minimum damage. An experimental design was used to investigate the effect of microwave time, pH, and avocado leaves (independent variables) on avocado flavor (response) using solid-phase microextraction (SPME)-GC-MS. Among the fully characterized flavor volatiles, 19 compounds were derived from lipid oxidation and only 4 from the avocado leaves. The main components derived from lipids were aldehydes, ketones and alcohols. Terpenoids, estragole, and 2-hexenal [E] were volatiles derived from avocado leaves. When leaves were added to fresh and microwaved avocado terpenoids and 2-hexenal [E]/hexanal ratio increased, this behavior was considered to have a positive effect on the sensorial quality of the product. From the statistical analysis of the experimental design, it was possible to determinate that the most important factors influencing the abundance of flavor compounds derived from lipids were microwave time and pH. Maximum values of these compounds were detected at high levels of microwave time and low values of pH. On the other hand, response surface of terpenoids and estragole showed an increment when microwave time and avocado leaf was increased. The region of optimum response was 30 s microwave time, pH 5.5, and 1% of avocado leaf. PMID:15139417

  20. Effects of volatile organic compounds from Streptomyces albulus NJZJSA2 on growth of two fungal pathogens.

    PubMed

    Wu, Yuncheng; Yuan, Jun; E, Yaoyao; Raza, Waseem; Shen, Qirong; Huang, Qiwei

    2015-09-01

    A Streptomyces albulus strain NJZJSA2 was isolated from the forest soil sample of Tzu-chin Mountain (Nanjing China) and identified based on its morphological and physiological properties and 16S rDNA gene sequence analysis. The strain S. albulus NJZJSA2 was evaluated for the production of antifungal volatile organic compounds (VOCs) against two fungal pathogens. Results showed that the VOCs generated by S. albulus NJZJSA2 inhibited mycelial growth of Sclerotinia sclerotiorum (SS) and Fusarium oxysporum (FO) by 100 and 56.3%, respectively. The germination of SS sclerotia and FO conidia was completely inhibited in the presence of VOCs produced by S. albulus NJZJSA2 in vitro. In soil, the VOCs delayed the germination of SS sclerotia and inhibited the germination of FO conidia for 45 days. The strain S. albulus NJZJSA2 was able to produce 13 VOCs based on GC/MS analyses. Among those, six compounds were purchased and used for the antifungal activity assay. Three relatively abundant VOCs, 4-methoxystyrene, 2-pentylfuran, and anisole were proved to have antifungal activity. Microscopy analysis showed that the pathogen hyphae were shriveled and damaged after treatment with 4-methoxystyrene. These results suggest that the S. albulus strain NJZJSA2 produce VOCs that not only reduce the growth of SS and FO, but also significantly inhibit the SS sclerotia and FO conidia. The results are useful for the better understanding of biocontrol mechanisms by S. albulus strains and will help to improve the biological control efficiency of lethal plant diseases. PMID:26059065

  1. Seasonal cycles of biogenic volatile organic compound fluxes and concentrations in a California citrus orchard

    NASA Astrophysics Data System (ADS)

    Fares, S.; Park, J.-H.; Gentner, D. R.; Weber, R.; Ormeño, E.; Karlik, J.; Goldstein, A. H.

    2012-07-01

    Orange trees are widely cultivated in Mediterranean climatic regions where they are an important agricultural crop. Citrus have been characterized as emitters of volatile organic compounds (VOC) in chamber studies under controlled environmental conditions, but an extensive characterization at field scale has never been performed using modern measurement methods, and is particularly needed considering the complex interactions between the orchards and the polluted atmosphere in which Citrus is often cultivated. For one year, in a Valencia orange orchard in Exeter, California, we measured fluxes using PTRMS (Proton Transfer Reaction Mass Spectrometer) and eddy covariance for the most abundant VOC typically emitted from citrus vegetation: methanol, acetone, and isoprenoids. Concentration gradients of additional oxygenated and aromatic compounds from the ground level to above the canopy were also measured. In order to characterize concentrations of speciated biogenic VOC (BVOC) in leaves, we analyzed leaf content by GC-MS (Gas Chromatography-Mass Spectrometery) regularly throughout the year. We also characterize in more detail concentrations of speciated BVOC in the air above the orchard by in-situ GC-MS during a few weeks in spring flowering and summer periods. Here we report concentrations and fluxes of the main VOC species emitted by the orchard, discuss how fluxes measured in the field relate to previous studies made with plant enclosures, and describe how VOC content in leaves and emissions change during the year in response to phenological and environmental parameters. The orchard was a source of monoterpenes and oxygenated VOC. The highest emissions were observed during the springtime flowering period, with mid-day fluxes above 2 nmol m-2 s-1 for methanol and up to 1 nmol m-2 s-1 for acetone and monoterpenes. During hot summer days emissions were not as high as we expected considering the known dependence of biogenic emissions on temperature. We provide evidence

  2. Seasonal cycles of biogenic volatile organic compound fluxes and concentrations in a California citrus orchard

    NASA Astrophysics Data System (ADS)

    Fares, S.; Park, J.-H.; Gentner, D. R.; Weber, R.; Ormeño, E.; Karlik, J.; Goldstein, A. H.

    2012-10-01

    Orange trees are widely cultivated in Mediterranean climatic regions where they are an important agricultural crop. Citrus have been characterized as emitters of volatile organic compounds (VOC) in chamber studies under controlled environmental conditions, but an extensive characterization at field scale has never been performed using modern measurement methods, and is particularly needed considering the complex interactions between the orchards and the polluted atmosphere in which Citrus is often cultivated. For one year, in a Valencia orange orchard in Exeter, California, we measured fluxes using PTRMS (Proton Transfer Reaction Mass Spectrometer) and eddy covariance for the most abundant VOC typically emitted from citrus vegetation: methanol, acetone, and isoprenoids. Concentration gradients of additional oxygenated and aromatic compounds from the ground level to above the canopy were also measured. In order to characterize concentrations of speciated biogenic VOC (BVOC) in leaves, we analyzed leaf content by GC-MS (Gas Chromatography - Mass Spectrometery) regularly throughout the year. We also characterized in more detail concentrations of speciated BVOC in the air above the orchard by in-situ GC-MS during a few weeks in spring flowering and summer periods. Here we report concentrations and fluxes of the main VOC species emitted by the orchard, discuss how fluxes measured in the field relate to previous studies made with plant enclosures, and describe how VOC content in leaves and emissions change during the year in response to phenological and environmental parameters. The orchard was a source of monoterpenes and oxygenated VOC. The highest emissions were observed during the springtime flowering period, with mid-day fluxes above 2 nmol m-2 s-1 for methanol and up to 1 nmol m-2 s-1 for acetone and monoterpenes. During hot summer days emissions were not as high as we expected considering the known dependence of biogenic emissions on temperature. We provide

  3. Volatile organic compounds (VOCs) in photochemically aged air from the Eastern and Western Mediterranean

    NASA Astrophysics Data System (ADS)

    Derstroff, Bettina; Stoenner, Christof; Klüpfel, Thomas; Sauvage, Carina; Crowley, John; Phillips, Gavin; Parchatka, Uwe; Lelieveld, Jos; Williams, Jonathan

    2015-04-01

    In summer 2014 a comprehensively instrumented measurement campaign (CYPHEX) was conducted in northwest Cyprus in order to investigate atmospheric oxidation chemistry in the Mediterranean region. The site was periodically influenced by the northerly Etesian winds advecting air from Eastern Europe (Turkey and Greece) and from westerly winds bringing more photochemically processed emissions from Western Europe (Spain and France). In this study the data from a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS) are analyzed. Generally, oxidized volatile organic compounds (OVOCs) such as methanol and acetone were measured in high mixing ratios (max. 9.5 ppb, min. 1.3 ppb, average 3.2 ppb for methanol, max. 7.9 ppb, min. 1.3 ppb, average 2.4 ppb for acetone ) while precursors like propane showed low values (max. 500 ppt). This demonstrates that the air measured was oxidized to a high degree over the Mediterranean Sea. Low values of acetonitrile throughout the campaign indicated no significant influence of biomass burning on the data. Temporal variations in VOC mixing ratios and precursor/product ratios over the campaign can be explained by using the HYSPLIT backward trajectory model which delineated air masses originating from Eastern and Western Europe. Diel variations of reactive VOCs such as isoprene and terpenes were also observed at the site. A sharp increase in isoprene and monoterpenes at circa 9:00 local time indicated that the 600 m hilltop site was influenced by ascending boundary layer air at this time. In this study, particular emphasis is placed on acetic (ethanoic) acid measured by PTR- TOF-MS and calibrated by a permeation source. Acetic acid is an atmospheric oxidation product of multiple volatile organic compounds, emitted directly from vegetation, and found in abundance in the Mediterranean region (max. 2.7 ppb, min. 0.2 ppb, average 0.8 ppb). Acetic acid contributes to the acidity of precipitation in remote areas, can be incorporated

  4. How well do we know the Martian abundances of highly volatile elements

    NASA Technical Reports Server (NTRS)

    Bogard, Donald

    1988-01-01

    The table is given that summarizes four models based on observations and gives some reasonable inferences of each for Martian volatiles. The table columns give: (1) the volatile assumptions of the model; (2) the inferred Martian volatile concentrations relative to earth; (3) the N/36 Ar and C/36 Ar ratios; (4) the percentage of Martian degassing inferred by the model, and 5 and 6) the equivalent global column heights of liquid water and solid CaCO3 over the entire surface of Mars that would be formed from the model quantities of degassed volatiles.

  5. Volatile metabolites in occupational exposure to organic sulfur compounds.

    PubMed

    Jäppinen, P; Kangas, J; Silakoski, L; Savolainen, H

    1993-01-01

    Dimethyl sulfide in breath was determined by the gas chromatographic method in 14 persons exposed to organic reduced sulfur compounds in sulfate pulp mills. Dimethyl sulfide concentrations in breath (range 0.04-0.69 cm3/m3 were compared to the combined workplace concentrations of methyl mercaptan, dimethyl sulfide and dimethyl disulfide. This method of analysis proved to be a practical noninvasive way to assess recent exposure, and therefore it should be applicable to workplaces contaminated with organic sulfur compounds in the pulp industry. PMID:8481097

  6. Calculated volatilization rates of fuel oxygenate compounds and other gasoline-related compounds from rivers and streams

    USGS Publications Warehouse

    Pankow, J.F.; Rathbun, R.E.; Zogorski, J.S.

    1996-01-01

    Large amounts of the 'fuel-oxygenate' compound methyl-tert-butyl ether (MTBE) are currently being used in gasoline to reduce carbon monoxide and ozone in urban air and to boost fuel octane. Because MTBE can be transported to surface waters in various ways, established theory was used to calculate half-lives for MTBE volatilizing from flowing surface waters. Similar calculations were made for benzene as a representative of the 'BTEX' group of compounds (benzene, toluene, ethyl benzene, and the xylenes), and for tert-butyl alcohol (TBA). The calculations were made as a function of the mean flow velocity u (m/day), the mean flow depth h (m), the ambient temperature, and the wind speed. In deep, slow-moving flows, MTBE volatilizes at rates which are similar to those for the BTEX compounds. In shallow, fast-moving flows, MTBE volatilizes more slowly than benzene, though in such flows both MTBE and benzene volatilize quickly enough that these differences may often not have much practical significance. TBA was found to be essentially nonvolatile from water.

  7. Identification and quantification of volatile organic compounds using systematic single-ion chromatograms

    SciTech Connect

    Tsuchiya, Yoshio; Kanabus-Kaminska, J.M.

    1996-12-31

    In order to determine the background level of volatile organic compounds (VOCs) in Canadian indoor air, a method of identification and quantification at a level of 0.3 {micro}g/m{sup 3} using systematic single-ion chromatograms (SICs) has been developed. The compounds selected for measurement included several halogenated compounds, oxygen compounds, terpenes, and C8 to C16 n-alkanes. Air samples were taken in 3-layered sorbent tubes and trapped compounds were thermally desorbed into the helium stream of a gas chromatograph/mass spectrometer (GC/MS) analytical system. Total quantities of volatile organic compounds (TVOCs) were measured using a flame ionization detector (FID). Individual compounds were analyzed by a GC/MS. For the identification of compounds in the main stream GC effluent, both the specific GC retention and mass spectra were used. About 50 selected SICs were routinely extracted from a total ion chromatogram (TIC) to detect and quantify compounds. For each compound, a single representative ion was selected. The specific retention was calculated from the elution time on the SIC. For quantification, ion counts under a peak in the SIC were measured. The single-ion MS response factor for some of the compounds was experimentally determined using a dynamic reference procedure.

  8. Volatile isoprenoids as defense compounds during abiotic stress in tropical plants

    NASA Astrophysics Data System (ADS)

    Jardine, K.

    2015-12-01

    Emissions of volatile isoprenoids from tropical forests play central roles in atmospheric processes by fueling atmospheric chemistry resulting in modified aerosol and cloud lifecycles and their associated feedbacks with the terrestrial biosphere. However, the identities of tropical isoprenoids, their biological and environmental controls, and functions within plants and ecosystems remain highly uncertain. As part of the DOE ARM program's GoAmazon 2014/15 campaign, extensive field and laboratory observations of volatile isoprenoids are being conducted in the central Amazon. Here we report the results of our completed and ongoing activities at the ZF2 forest reserve in the central Amazon. Among the results of the research are the suprisingly high abundance of light-dependent volatile isoprenoid emissions across abundant tree genera in the Amazon in both primary and secondary forests, the discovery of highly reactive monoterpene emissions from Amazon trees, and evidence for the importance of volatile isoprenoids in protecting photosynthesis during oxidative stress under elevated temperatures including energy consumption and direct antioxidant functions and a tight connection betwen volatile isoprenoid emissions, photorespiration, and CO2 recycling within leaves. The results highlight the need to model allocation of carbon to isoprenoids during elevated temperature stress in the tropics.

  9. Distribution of volatile organic compounds in a New Jersey coastal plain aquifer system

    USGS Publications Warehouse

    Fusillo, T.V.; Hochreiter, J.J., Jr.; Lord, D.G.

    1985-01-01

    Samples for analysis of volatile organic compounds were collected from 315 wells in the Potomac-Raritan-Magothy aquifer system in southwestern New Jersey and a small adjacent area in Pennsylvania during 1980-82. Volatile organic compounds were detected in all three aquifer units of the Potomac-Raritan-Magoth aquifer system in the study area. Most of the contamination appears to be confined to the outcrop area at present. Low levels of contamination, however, were found downdip of the outcrop area in the upper and middle aquifers. Trichloroethylene, tetrachloroethylene, and benzene were the most frequently detected compounds. Differences in the areal distributions of light chlorinated hydrocarbons, such as trichloroethylene, and aromatic hydrocarbons, such as benzene, were noted and are probably due to differences in the uses of the compounds and the distribution patterns of potential contamination sources. The distribution patterns of volatile organic compounds differed greatly among the three aquifer units. The upper aquifer, which crops out mostly in less-developed areas, had the lowest percentage of wells with volatile organic compounds detected (10 percent of wells sampled). The concentrations in most wells in the upper aquifer which had detectable levels were less than 10 ??g/l. In the middle aquifer, which crops out beneath much of the urban and industrial area adjacent to the Delaware River, detectable levels of volatile organic compounds were found in 22 percent of wells sampled, and several wells contained concentrations above 100 ??g/l. The lower aquifer, which is confined beneath much of the outcrop area of the aquifer system, had the highest percentage of wells (28 percent) with detectable levels. This is probably due to (1) vertical leakage of contamination from the middle aquifer, and (2) the high percentage of wells tapping the lower aquifer in the most heavily developed areas of the outcrop.

  10. Influence of rearing conditions on the volatile compounds of cooked fillets of Silurus glanis (European catfish).

    PubMed

    Hallier, Arnaud; Prost, Carole; Serot, Thierry

    2005-09-01

    Volatile compounds of cooked fillets of Silurus glanis reared under two conditions occurring in France were studied. They were extracted by dynamic headspace, identified by gas chromatography/mass spectrometry, and quantified by gas chromatography-flame ionization detection. Odor active volatile compounds were characterized by gas chromatography-olfactometry. Sixty volatile compounds were detected in dynamic headspace extracts, among which 33 were odor active. Rearing conditions affected their estimated concentrations and their odor intensities, but very few qualitative differences were exhibited (only seven volatile compounds were concerned). A good correlation between quantitative and olfactometric results is shown. 2-Methylisoborneol and (E)-2-hexenal were less represented in OUTDOOR extracts, while 2-butanone was less represented in INDOOR extracts. In addition, olfactometric results can be closely related to those previously obtained by sensory analysis. Boiled potato sensory odor of the silurus cooked fillets can be related to (Z)-4-heptenal and methional, and buttery odor can be related to 2,3-butanedione, an unknown compound (RI = 1010), and 2,3-pentadione. PMID:16131131

  11. Lipid oxidation in baked products: impact of formula and process on the generation of volatile compounds.

    PubMed

    Maire, Murielle; Rega, Barbara; Cuvelier, Marie-Elisabeth; Soto, Paola; Giampaoli, Pierre

    2013-12-15

    This paper investigates the effect of ingredients on the reactions occurring during the making of sponge cake and leading to the generation of volatile compounds related to flavour quality. To obtain systems sensitive to lipid oxidation (LO), a formulation design was applied varying the composition of fatty matter and eggs. Oxidation of polyunsaturated fatty acids (PUFA) and formation of related volatile compounds were followed at the different steps of cake-making. Optimised dynamic Solid Phase Micro Extraction was applied to selectively extract either volatile or semi-volatile compounds directly from the baking vapours. We show for the first time that in the case of alveolar baked products, lipid oxidation occurs very early during the step of dough preparation and to a minor extent during the baking process. The generation of lipid oxidation compounds depends on PUFA content and on the presence of endogenous antioxidants in the raw matter. Egg yolk seemed to play a double role on reactivity: protecting unsaturated lipids from oxidation and being necessary to generate a broad class of compounds of the Maillard reaction during baking and linked to the typical flavour of sponge cake. PMID:23993514

  12. 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. PMID:26434291

  13. Volatile compounds in acacia, chestnut, cherry, ash, and oak woods, with a view to their use in cooperage.

    PubMed

    de Simón, Brígida Fernández; Esteruelas, Enrique; Muñoz, Angel M; Cadahía, Estrella; Sanz, Miriam

    2009-04-22

    Extracts of wood from acacia, European ash, American ash, chestnut, cherry, and three oak species (Quercus pyrenaica, Quercus alba and Quercus petraea) before and after toasting in cooperage were studied by GC-MS. 110 compounds were detected, and 97 of them were identified. In general, all studied woods showed more lignin derivatives than lipid and carbohydrate derivatives, with a higher variety of compounds detected and abundance of them. The toasting led to an increase in the concentrations of most of these compounds, and this increase is especially important in acacia, chestnut and ash woods. The cis and trans isomers of beta-methyl-gamma-octalactone and isobutyrovanillone were only detected in oak wood, 3,4-dimethoxyphenol and 2,4-dihydroxybenzaldehyde only in acacia wood, and p-anisaldehyde and benzylsalicylate only in cherry wood, before and after toasting, and these compounds could be considered chemical markers for each one of these woods. Moreover, each wood has a characteristic volatile composition, from a quantitative point of view, and therefore we can expect a characteristic sensorial profile. The oak wood turned out to be the most balanced, since although it provides a lot of volatile compounds to the aroma and flavor of aged wine, it can do so without masking their primary and secondary aroma. On the whole, toasted acacia and chestnut woods showed a very high richness of studied compounds, as lignin as lipid and carbohydrate derivatives, while cherry and ash were much richer than toasted oak wood in lignin derivatives, but much poorer in lipid and carbohydrate derivatives. PMID:19290598

  14. Abundances of volatile-bearing phases in carbonaceous chondrites and cooling rates of meteorites based on cation ordering of orthopyroxenes

    NASA Technical Reports Server (NTRS)

    Ganguly, Jibamitra

    1989-01-01

    Results of preliminary calculations of volatile abundances in carbonaceous chondrites are discussed. The method (Ganguly 1982) was refined for the calculation of cooling rate on the basis of cation ordering in orthopyroxenes, and it was applied to the derivation of cooling rates of some stony meteorites. Evaluation of cooling rate is important to the analysis of condensation, accretion, and post-accretionary metamorphic histories of meteorites. The method of orthopyroxene speedometry is widely applicable to meteorites and would be very useful in the understanding of the evolutionary histories of carbonaceous chondrites, especially since the conventional metallographic and fission track methods yield widely different results in many cases. Abstracts are given which summarize the major conclusions of the volatile abundance and cooling rate calculations.

  15. Blood and breath levels of selected volatile organic compounds in healthy volunteers

    PubMed Central

    King, Julian; Klieber, Martin; Unterkofler, Karl; Hinterhuber, Hartmann; Baumann, Matthias

    2016-01-01

    Gas chromatography with mass spectrometric detection (GC-MS) was used to identify and quantify volatile organic compounds in the blood and breath of healthy individuals. Blood and breath volatiles were preconcentrated using headspace solid phase micro-extraction (HS-SPME) and needle trap devices (NTDs), respectively. The study involved a group of 28 healthy test subjects and resulted in the quantification of a total of 74 compounds in both types of samples. The concentrations of the species under study varied between 0.01 and 6700 nmol L−1 in blood and between 0.02 and 2500 ppb in exhaled air. Limits of detection (LOD) ranged from 0.01 to 270 nmol L−1 for blood compounds and from 0.01 to 0.7 ppb for breath species. Relative standard deviations for both measurement regimes varied from 1.5 to 14%. The predominant chemical classes among the compounds quantified were hydrocarbons (24), ketones (10), terpenes (8), heterocyclic compounds (7) and aromatic compounds (7). Twelve analytes were found to be highly present in both blood and exhaled air (with incidence rates higher than 80%) and for 32 species significant differences (Wilcoxon signed-rank test) between room air and exhaled breath were observed. By comparing blood, room air and breath levels in parallel, a tentative classification of volatiles into endogenous and exogenous compounds can be achieved. PMID:23435188

  16. Diet-induced and mono-genetic obesity alter volatile organic compound signature in mice.

    PubMed

    Kistler, Martin; Muntean, Andreea; Szymczak, Wilfried; Rink, Nadine; Fuchs, Helmut; Gailus-Durner, Valerie; Wurst, Wolfgang; Hoeschen, Christoph; Klingenspor, Martin; Hrabě de Angelis, Martin; Rozman, Jan

    2016-03-01

    The prevalence of obesity is still rising in many countries, resulting in an increased risk of associated metabolic diseases. In this study we aimed to describe the volatile organic compound (VOC) patterns symptomatic for obesity. We analyzed high fat diet (HFD) induced obese and mono-genetic obese mice (global knock-in mutation in melanocortin-4 receptor MC4R-ki). The source strengths of 208 VOCs were analyzed in ad libitum fed mice and after overnight food restriction. Volatiles relevant for a random forest-based separation of obese mice were detected (26 in MC4R-ki, 22 in HFD mice). Eight volatiles were found to be important in both obesity models. Interestingly, by creating a partial correlation network of the volatile metabolites, the chemical and metabolic origins of several volatiles were identified. HFD-induced obese mice showed an elevation in the ketone body acetone and acrolein, a marker of lipid peroxidation, and several unidentified volatiles. In MC4R-ki mice, several yet-unidentified VOCs were found to be altered. Remarkably, the pheromone (methylthio)methanethiol was found to be reduced, linking metabolic dysfunction and reproduction. The signature of volatile metabolites can be instrumental in identifying and monitoring metabolic disease states, as shown in the screening of the two obese mouse models in this study. Our findings show the potential of breath gas analysis to non-invasively assess metabolic alterations for personalized diagnosis. PMID:26860833

  17. Flavour compounds in tomato fruits: identification of loci and potential pathways affecting volatile composition.

    PubMed

    Mathieu, Sandrine; Cin, Valeriano Dal; Fei, Zhangjun; Li, Hua; Bliss, Peter; Taylor, Mark G; Klee, Harry J; Tieman, Denise M

    2009-01-01

    The unique flavour of a tomato fruit is the sum of a complex interaction among sugars, acids, and a large set of volatile compounds. While it is generally acknowledged that the flavour of commercially produced tomatoes is inferior, the biochemical and genetic complexity of the trait has made breeding for improved flavour extremely difficult. The volatiles, in particular, present a major challenge for flavour improvement, being generated from a diverse set of lipid, amino acid, and carotenoid precursors. Very few genes controlling their biosynthesis have been identified. New quantitative trait loci (QTLs) that affect the volatile emissions of red-ripe fruits are described here. A population of introgression lines derived from a cross between the cultivated tomato Solanum lycopersicum and its wild relative, S. habrochaites, was characterized over multiple seasons and locations. A total of 30 QTLs affecting the emission of one or more volatiles were mapped. The data from this mapping project, combined with previously collected data on an IL population derived from a cross between S. lycopersicum and S. pennellii populations, were used to construct a correlational database. A metabolite tree derived from these data provides new insights into the pathways for the synthesis of several of these volatiles. One QTL is a novel locus affecting fruit carotenoid content on chromosome 2. Volatile emissions from this and other lines indicate that the linear and cyclic apocarotenoid volatiles are probably derived from separate carotenoid pools. PMID:19088332

  18. Flow-modulated targeted signal enhancement for volatile organic compounds.

    PubMed

    Hayward, Taylor; Gras, Ronda; Luong, Jim

    2016-06-01

    Comprehensive two-dimensional gas chromatography is a technique that is becoming more widespread within the analytical community, especially in the separation of complex mixtures. Modulation in comprehensive two-dimensional gas chromatography can be achieved by manipulating temperature or flow and offers many advantages such as increased separation power, but one underutilized advantage is increased detectability due to the reduction of peak width from the use of a modulator. A flow modulator was used to selectively target analytes for increased detectability with a standard flame ionization detector operated at 100 Hz, without the need for cryogens or advanced modulation software. By the collection of the entire peak volume followed by peak transfer rather than further separation, an increase of 12 times in peak height and detectability was realized for the analytes tested using an internal loop modulator configuration. An external loop flow modulator configuration allowed for more volatile analytes (with k < 5), and demonstrated an analyte detectability enhancement factor of at least 6. The collection loop size can be readily increased with an external loop configuration to accommodate for these naturally broader peaks. This novel flow modulated targeted signal enhancement approach was applied to industrially significant analyses like the analysis of methanol in a hydrocarbon streams. Methanol was detected at 7 ppb with a conventional flame ionization detector and without the need for pre-concentration. PMID:27120133

  19. The human volatilome: volatile organic compounds (VOCs) in exhaled breath, skin emanations, urine, feces and saliva.

    PubMed

    Amann, Anton; Costello, Ben de Lacy; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Pleil, Joachim; Ratcliffe, Norman; Risby, Terence

    2014-09-01

    Breath analysis is a young field of research with its roots in antiquity. Antoine Lavoisier discovered carbon dioxide in exhaled breath during the period 1777-1783, Wilhelm (Vilém) Petters discovered acetone in breath in 1857 and Johannes Müller reported the first quantitative measurements of acetone in 1898. A recent review reported 1765 volatile compounds appearing in exhaled breath, skin emanations, urine, saliva, human breast milk, blood and feces. For a large number of compounds, real-time analysis of exhaled breath or skin emanations has been performed, e.g., during exertion of effort on a stationary bicycle or during sleep. Volatile compounds in exhaled breath, which record historical exposure, are called the 'exposome'. Changes in biogenic volatile organic compound concentrations can be used to mirror metabolic or (patho)physiological processes in the whole body or blood concentrations of drugs (e.g. propofol) in clinical settings-even during artificial ventilation or during surgery. Also compounds released by bacterial strains like Pseudomonas aeruginosa or Streptococcus pneumonia could be very interesting. Methyl methacrylate (CAS 80-62-6), for example, was observed in the headspace of Streptococcus pneumonia in concentrations up to 1420 ppb. Fecal volatiles have been implicated in differentiating certain infectious bowel diseases such as Clostridium difficile, Campylobacter, Salmonella and Cholera. They have also been used to differentiate other non-infectious conditions such as irritable bowel syndrome and inflammatory bowel disease. In addition, alterations in urine volatiles have been used to detect urinary tract infections, bladder, prostate and other cancers. Peroxidation of lipids and other biomolecules by reactive oxygen species produce volatile compounds like ethane and 1-pentane. Noninvasive detection and therapeutic monitoring of oxidative stress would be highly desirable in autoimmunological, neurological, inflammatory diseases and cancer

  20. [Ammonia volatilization of slow release compound fertilizer in different soils water conditions].

    PubMed

    Hu, Xiao-feng; Wang, Zheng-yin; You, Yuan; Li, Jing-chao

    2010-08-01

    By using venting method incubation experiment, we studied the ammonia volatilization and kinetics characteristics of uncoated slowed release compound fertilizer (SRF) under different soil water conditions and the growth and nitrogen utilization efficiency of rice in pot experiment. Results indicated that the ammonia volatilization of SRF under waterflooding reached the peak ahead of 3-4 days compared to the moist treatment. The peak and accumulation of ammonia volatilization in the waterflooding treatments were higher than those under the moist condition. SRF could significantly reduce total ammonia volatilization compared to the common compound fertilizer (CCF), reduced by 50.6% and 22.8% in the moist treatment and reduced by 24.2% and 10.4% in the waterflooding treatment,but the loss of ammonia volatilization of SRF was higher significantly than that of the coated fertilizer (CRF). Ammonia volatilization increased with the increasing of fertilizer application. The dynamics of ammonia volatilization of SRF could be quantitatively described with three equations: the first order kinetics equation, Elovich equation and parabola equation. Compared to moist condition, the biomass of rice plant in SRF, CCF and SRF treatments increased by 67.86%, 78.25% and 48.75%, and nitrogen utilization efficiency increased by 57.73%, 80.70% and 12.06% under waterflooding condition, respectively. Comparing with CCF, nitrogen utilization efficiency in SRF treatment improved by 59.10% and 10.40% under two soil moisture conditions. SRF could reduce ammonia volatilization and improve biomass and nitrogen utilization efficiency. PMID:21090317

  1. HS-SPME analysis of volatile organic compounds of coniferous needle litter

    NASA Astrophysics Data System (ADS)

    Isidorov, V. A.; Vinogorova, V. T.; Rafałowski, K.

    The composition of volatile emission of Scots pine ( Pinus sylvestris) and spruce ( Picea exelsa) litter was studied by gas chromatography-mass spectrometry (GC-MS) and samples were collected by solid-phase microextraction (SPME) method. The list of identified compounds includes over 60 organic substances of different classes. It was established that volatile emission contain not only components of essential oils of pine and spruce needles but also a large number of organic compounds which are probably secondary metabolites of litter-decomposing fungi. They include lower carbonyl compounds and alcohols as well as products of terpene dehydration and oxidation. These data show that the processes of litter decomposition are an important source of reactive organic compounds under canopy of coniferous forests.

  2. Influence of filtration on volatile compounds and sensory profile of virgin olive oils.

    PubMed

    Brkić Bubola, Karolina; Koprivnjak, Olivera; Sladonja, Barbara

    2012-05-01

    The influence of filtration through a hydrophilic cotton layer on volatile compounds, sensory characteristics and colour of two monovarietal oils was investigated in this study. Volatiles were evaluated using headspace solid-phase microextraction-gas chromatography. After the filtration of Buža oils only a slight increase in total alcohols was noticed. In filtered Črna oils a significant decrease of total alcohols and slight changes in total aldehydes, total ketones and total C5 volatile compounds concentration were detected. No significant influence on the sensory scores of oils, but some slight changes in sensorial profiles were noted (slightly higher intensities of sensory characteristics apple and grass, and higher values of the lightness L(∗) in filtered samples). The results point to unequal filtration impact on different monovarietal oils and could be useful in developing targeted technologies for specific monovarietal oils quality improvement. PMID:26434268

  3. 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.

  4. 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.

  5. RECOVERY OF SEMI-VOLATILE ORGANIC COMPOUNDS DURING SAMPLE PREPARATION: IMPLICATIONS FOR CHARACTERIZATION OF AIRBORNE PARTICULATE MATTER

    EPA Science Inventory

    Semi-volatile compounds present special analytical challenges not met by conventional methods for analysis of ambient particulate matter (PM). Accurate quantification of PM-associated organic compounds requires validation of the laboratory procedures for recovery over a wide v...

  6. NATURAL EMISSIONS OF NON-METHANE VOLATILE ORGANIC COMPOUNDS, CARBON MONOXIDE, AND OXIDES OF NITROGEN FROM NORTH AMERICA

    EPA Science Inventory

    The magnitudes, distributions, controlling processes and uncertainties associated with North American natural emissions of oxidant precursors are reviewed. Natural emissions are repsonsible for a major portion of the compounds, including non-methane volatile organic compounds (N...

  7. 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

  8. Analysis of semi-volatile organic compounds using supercritical fluid methodologies

    SciTech Connect

    Wright, B.W.; Chess, E.K.; Yonker, C.R.; Smith, R.D.

    1985-06-01

    This study demonstrates the applicability of supercritical fluid chromatography (SFC) and analytical supercritical fluid extraction (SFE) for the analysis of semi-volatile compounds. Mixtures of nitro-polycyclic aromatic hydrocarbons that are not ammenable to gas chromatography were separated using SFC with tentative compound identifications made by SFC-MS. Comparisons of analytical SFE of XAD-2 resin and NBS Urban Dust (SRM 1649) to conventional Soxhlet extraction are also discussed.

  9. Nitrogen-Containing Low Volatile Compounds from Pinonaldehyde-Dimethylamine Reaction in the Atmosphere: A Laboratory and Field Study.

    PubMed

    Duporté, Geoffroy; Parshintsev, Jevgeni; Barreira, Luís M F; Hartonen, Kari; Kulmala, Markku; Riekkola, Marja-Liisa

    2016-05-01

    Pinonaldehyde, which is among the most abundant oxidation products of α-pinene, and dimethylamine were selected to study the formation of N-containing low volatile compounds from aldehyde-amine reactions in the atmosphere. Gas phase reactions took place in a Tedlar bag, which was connected to a mass spectrometer ionization source via a short deactivated fused silica column. In addition to on-line analysis, abundance of gaseous precursors and reaction products were monitored off-line. Condensable products were extracted from the bag's walls with a suitable solvent and analyzed by gas chromatography coupled to chemical ionization high-resolution quadrupole time-of-flight mass spectrometry and by ultra-high-performance liquid chromatography coupled to electrospray ionization Orbitrap mass spectrometry. The reactions carried out resulted in several mid-low vapor pressure nitrogen-containing compounds that are potentially important for the formation of secondary organic aerosols in the atmosphere. Further, the presence of brown carbon, confirmed by liquid chromatography-UV-vis-mass spectrometry, was observed. Some of the compounds identified in the laboratory study were also observed in aerosol samples collected at SMEAR II station (Hyytiälä, Finland) in August 2015 suggesting the importance of aldehyde-amine reactions for the aerosol formation and growth. PMID:27035788

  10. Microbial production of volatile sulphur compounds in the large intestine of pigs fed two different diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Only little is known about the microbial production of volatile sulphur compounds (VSC) in the 18 gastrointestinal tract, the dietary influence, and the magnitude of this production. To investigate intestinal VSC production in more detail, pigs were fed diets based on either wheat and barley (CONTRO...

  11. 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 PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Storage Vessels for Petroleum Liquids...

  12. 78 FR 78726 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ...The Environmental Protection Agency (EPA) is approving a request from the Indiana Department of Environmental Management to revise its volatile organic compound state implementation plan (SIP) for industrial solvent cleaning rule for manufacturers of coatings, inks, adhesives, and resins. These revisions are approvable because they are consistent with EPA's Industrial Solvent Cleaning Control......

  13. THEORETICAL DEVELOPMENT AND ANALYTICAL SOLUTIONS FOR TRANSPORT OF VOLATILE ORGANIC COMPOUNDS IN DUAL-POROSITY SOILS

    EPA Science Inventory

    Predicting the behavior of volatile organic compounds in soils or sediments is necessary for managing their use and designing appropriate remedial systems to eliminate potential threats to the environment, particularly the air and groundwater resources. In this effort, based on c...

  14. NATURAL VOLATILE ORGANIC COMPOUND EMISSION RATE ESTIMATES FOR U.S. WOODLAND LANDSCAPES

    EPA Science Inventory

    Volatile organic compound (VOC) emission rate factors are estimated for 49 tree genera based on a review of foliar emission rate measurements. oliar VOC emissions are grouped into three categories: isoprene, monoterpenes and other VOC'S. ypical emission rates at a leaf temperatur...

  15. COMPARISON OF TWO FIELD SAMPLING PROCEDURES (EN CORE AND FIELD METHANOL EXTRACTION) FOR VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    In-situ Lasagna technology was recently evaluated at a contaminated site at Offutt Air Force Base. The site was contaminated with low levels (< 30 mg/kg) of volatile organic compounds (VOCs). Originally, researchers planned to use field methanol extraction for both pre- and pos...

  16. IMPROVED METHOD FOR ESTIMATING MOLECULAR WEIGHTS OF VOLATILE ORGANIC COMPOUNDS FROM LOW RESOLUTION MASS SPECTRA

    EPA Science Inventory

    An improved method of estimating molecular weights of volatile organic compound from their mass spectra has been developed and implemented with an expert system. he method is based on the strong correlation of MAXMASS, the highest mass with an intensity of 5% of the base peak in ...

  17. AMBIENT LEVEL VOLATILE ORGANIC COMPOUND (VOC) MONITORING USING SOLID ADSORBANTS - RECENT U.S. EPA STUDIES

    EPA Science Inventory

    Ambient air spiked with 1-10 ppbv concentrations of 41 toxic volatile organic compounds (VOCs) listed in U.S. Environmental Protection Agency (EPA) Compendium Method TO-14A was monitored using solid sorbents for sample collection and a Varian Saturn 2000 ion trap mass spectrome...

  18. Emission rates of selected volatile organic compounds from skin of healthy volunteers

    PubMed Central

    Mochalski, Paweł; King, Julian; Unterkofler, Karl; Hinterhuber, Hartmann; Amann, Anton

    2014-01-01

    Gas chromatography with mass spectrometric detection (GC–MS) coupled with solid phase micro-extraction as pre-concentration method (SPME) was applied to identify and quantify volatile organic compounds (VOCs) emitted by human skin. A total of 64 C4-C10 compounds were quantified in skin emanation of 31 healthy volunteers. Amongst them aldehydes and hydrocarbons were the predominant chemical families with eighteen and seventeen species, respectively. Apart from these, there were eight ketones, six heterocyclic compounds, six terpenes, four esters, two alcohols, two volatile sulphur compounds, and one nitrile. The observed median emission rates ranged from 0.55 to 4790 fmol cm−2 min−1. Within this set of analytes three volatiles; acetone, 6-methyl-5-hepten-2-one, and acetaldehyde exhibited especially high emission rates exceeding 100 fmol cm−2 min−1. Thirty-three volatiles were highly present in skin emanation with incidence rates over 80%. These species can be considered as potential markers of human presence, which could be used for early location of entrapped victims during Urban Search and Rescue Operations (USaR). PMID:24768920

  19. Cold Temperature and Biodiesel Fuel Effects on Speciated Emissions of Volatile Organic Compounds from Diesel Trucks

    EPA Science Inventory

    Speciated volatile organic compounds (VOCs) were measured in diesel exhaust from three medium heavy-duty trucks equipped with modern aftertreatment technologies. Emissions testing was conducted on a chassis dynamometer at two ambient temperatures (-6.7°C and 21.7°C) operating on ...

  20. OPTIMIZATION OF MULTICOMPONENT PERVAPORATION FOR REMOVAL OF VOLATILE ORGANIC COMPOUNDS FROM WATER

    EPA Science Inventory

    Optimal operation of a hollow fiber membrane module for pervaporative removal of multicomponent volatile organic compounds (VOCS) from wastewater was studied. hell-and-tube heat-exchanger type of hollow fiber module was considered for treatment of a wastewater containing toluene,...

  1. 40 CFR 180.1127 - Biochemical pesticide plant floral volatile attractant compounds: cinnamaldehyde, cinnamyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Biochemical pesticide plant floral volatile attractant compounds: cinnamaldehyde, cinnamyl alcohol, 4-methoxy cinnamaldehyde, 3-phenyl propanol, 4-methoxy phenethyl alcohol, indole, and 1,2,4-trimethoxybenzene; exemptions from the requirement of a tolerance. 180.1127 Section...

  2. VOLATILE ORGANIC COMPOUNDS INHIBIT HUMAN AND RAT NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS EXPRESSED IN XENOPUS OOCYTES.

    EPA Science Inventory

    This manuscript provides evidence to indicate that rats and humans are equally sensitive at the pharmacodynamic level to effects of volatile organic compounds.

    ? This manuscript also presents novel data that provides a plausible mechanism, disruption of ion channel functi...

  3. A POLYMER-CERAMIC COMPOSITE MEMBRANE FOR RECOVERING VOLATILE ORGANIC COMPOUNDS FROM WASTEWATERS BY PERVAPORATION

    EPA Science Inventory

    A composite membrane was constructed on a porous ceramic support from a block copolymer of styrene and butadiene (SBS). It was tested in a laboratory pervaporation apparatus for recovering volatile organic compounds (VOCs) such a 1,1,1-trichloroethane (TCA) and trichloroethylene ...

  4. VOLATILE ORGANIC COMPOUNDS AND ISOPRENE OXIDATION PRODUCTS AT A TEMPERATE DECIDUOUS FOREST SITE

    EPA Science Inventory

    Biogenic volatile compounds (BVOCs) and their role in atmospheric oxidant formation were investigated at a forest site near Oak Ridge, Tennessee, as part of the Nashville Southern Oxidants Study (SOS) in July 1995. Of 98 VOCs detected, a major fraction were anthropogenic VOCs suc...

  5. BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM DESERT VEGETATION OF THE SOUTHWESTERN U.S.

    EPA Science Inventory

    Thirteen common plant species in the Mojave and Sonoran Desert regions of the western United States were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 µgCg−1 ...

  6. MEASUREMENTS OF VOLATILE ORGANIC COMPOUNDS AND PARTICLES DURING APPLICATION OF LATEX PAINT WITH AN AIRLESS SPRAYER

    EPA Science Inventory

    The paper discusses experiments, conducted at EPA's Indoor Air Quality Research House, to measure airborne concentrations of volatile organic compounds (VOCs) and particles during and following the spray-application of latex wall paint. (NOTE: Paint may be applied indoors by a v...

  7. Synthesis of a volatile compound of the (2 minus ) Ho-160 nuclear isomer

    SciTech Connect

    Hartmann, F.X.; Naumann, R.A. )

    1988-10-01

    The synthesis of volatile compounds of radioactive holmium atoms are described and the gamma-ray spectra following the decay of the longest-lived isomer (Ho-160) presented. This latter isomer has an ultra-low energy transition of potential interest in laser driven nuclear inter-level transfer studies.

  8. Emission of volatile organic compounds as affected by rate of application of cattle manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef cattle manure can serve as a valuable nutrient source for crop production. However, emissions of volatile organic compounds (VOCs) following land application may pose a potential off-site odor concern. This study was conducted to evaluate the effects of land application method, N- application...

  9. Emission of volatile organic compounds after land application of cattle manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef cattle manure can serve as a valuable source of nutrients for crop production. However, emissions of volatile organic compounds (VOCs) following land application may pose an odor nuisance to downwind populations. This study was conducted to evaluate the effects of application method, diet, so...

  10. COMPARISON OF SOLID ADSORBENT SAMPLING TECHNIQUES FOR VOLATILE ORGANIC COMPOUNDS IN AMBIENT AIR

    EPA Science Inventory

    The specific objective of the study was to compare the performance of three solid adsorbents (Tenax, an experimental polyimide resin, and Spherocarb) as well as cryogenic trapping/gas chromatography for sampling and analysis of a target list of volatile organic compounds in ambie...

  11. LONG-PATH FTIR MEASUREMENTS OF VOLATILE ORGANIC COMPOUNDS IN AN INDUSTRIAL SETTING

    EPA Science Inventory

    As part of a Superfund Innovative Technology Evaluation (SITE) field program, a Fourier transform infrared (FTIR) spectrometer vas used to make open path measurements of volatile organic compounds in the New Castle, Delaware, area. he SITE program requires that new technologies b...

  12. EVALUATION OF CONTROL STRATEGIES FOR VOLATILE ORGANIC COMPOUND IN INDOOR AIR

    EPA Science Inventory

    The Air and Energy Engineering Research Laboratory of the U.S. Environmental Protection Agency (U.S. EPA) conducts and sponsors research on technology to reduce or eliminate emissions of potentially toxic volatile organic compounds (VOCs) from industrial/commercial sources. The r...

  13. SOIL SORPTION OF VOLATILE AND SEMIVOLATILE ORGANIC COMPOUNDS IN A MIXTURE

    EPA Science Inventory

    Studies were conducted to evaluate lipophilicity as a predictor sorption for a mixture of organic compounds with high vapor pressures commonly present at hazardous waste sites. Sorption partition coefficients (Kp) for the mixture of 16 volatile and semivolatile ...

  14. FINAL REPORT: MEMBRANE-MEDIATED EXTRACTION AND BIODEGRADATION OF VOLATILE ORGANIC COMPOUNDS FROM AIR

    EPA Science Inventory

    The report describes feasibility tests of a two-step strategy for air pollution control applicable to exhaust air contaminated with volatile organic compounds (VOCs) from painting aircraft. In the first step, the VOC-contaminated air passes over coated, polypropylene, hollow-fibe...

  15. EVALUATION OF INNOVATIVE LOW-VOLATILE ORGANIC COMPOUND (VOC) INDUSTRIAL MAINTENANCE (IM) COATINGS

    EPA Science Inventory

    The paper discusses a field evaluation of the feasibility of using alternative low-volatile organic compound (VOC) coatings to replace higher-VOC coatings. he evaluation includes chemical, performance, and outdoor exposure testing. he feasibility of five alternative coatings for ...

  16. Modeling emissions of volatile organic compounds from silage storages and feed lanes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An initial volatile organic compound (VOC) emission model for silage sources, developed using experimental data from previous studies, was incorporated into the Integrated Farm System Model (IFSM), a whole-farm simulation model used to assess the performance, environmental impacts, and economics of ...

  17. A NOVEL ENERGY-EFFICIENT PLASMA CHEMICAL PROCESS FOR THE DESTRUCTION OF VOLATILE TOXIC COMPOUNDS

    EPA Science Inventory

    Removal of low-concentrations (below several percent) of toxic volatile compounds from contaminated air streams is encountered at DOE waste sites in two instances:(i) off-gases resulting from air-stripping of contaminated soils and (ii) effluent from the incineration of highly-co...

  18. ANALYSIS OF AMBIENT POLAR VOLATILE ORGANIC COMPOUNDS USING CHEMICAL IONIZATION -- ION TRAP DETECTOR

    EPA Science Inventory

    The current approach to measuring trace levels of volatile organic compounds (VOCs) in ambient air requires cryogenic trapping of the analytes, followed by thermal desorption and low-temperature refocussing onto a column for analysis by capillary gas chromatography/mass spectrome...

  19. VOLATILE ORGANIC COMPOUNDS AS BREATH BIOMARKERS FOR ACTIVE AND PASSIVE SMOKING

    EPA Science Inventory

    Real-time breath measurement technology was used to investigate the suitability of some volatile organic compounds (VOCs) to serve as breath biomarkers for active and passive smoking and to measure actual exposures and resulting breath concentrations for persons exposed to toba...

  20. INHIBITORY EFFECTS OF VOLATILE ORGANIC COMPOUNDS ON NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS.

    EPA Science Inventory

    INHIBITORY EFFECTS OF VOLATILE ORGANIC COMPOUNDS ON NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS.
    A.S. Bale*; P.J. Bushnell; C.A. Meacham; T.J. Shafer
    Neurotoxicology Division, NHEERL, ORD, US Environmental Protection Agency, Research Triangle Park, NC, USA
    Toluene (TOL...

  1. LEAF, BRANCH, STAND & LANDSCAPE SCALE MEASUREMENTS OF VOLATILE ORGANIC COMPOUND FLUXES FROM U.S. WOODLANDS

    EPA Science Inventory

    Natural volatile organic compounds (VOC) fluxes were measured in three U.S. woodlands in summer 1993. Fluxes from individual leaves and branches were estimated with enclosure techniques and used to initialize and evaluate VOC emission model estimates. Ambient measurements were us...

  2. EXPOSURE TO VOLATILE ORGANIC COMPOUNDS MEASURED IN A SOURCE IMPACTED AIRSHED

    EPA Science Inventory

    A three-year exposure monitoring study is being conducted in a large city in the Midwestern U.S. The study is aimed at determining the factors influencing exposures to air pollutants of outdoor origin, including volatile organic compounds (VOCs) and particulate matter.

  3. ISOTOPIC (14C) AND CHEMICAL COMPOSITION OF ATMOSPHERIC VOLATILE ORGANIC COMPOUND FRACTIONS - PRECURSORS TO OZONE FORMATION

    EPA Science Inventory

    Atmospheric volatile organic compounds (VOCs) are an important factor in the production of ozone near ground level [3]. Many hydrocarbons originate from auto exhaust. However, a number of VOCs, e.g., isoprene, are known to be natural in origin. To develop reliable models for un...

  4. BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM A LOWLAND TROPICAL WET FOREST IN COSTA RICA

    EPA Science Inventory

    Twenty common plant species were screened for emissions of biogenic volatile organic compounds (BVOCS) at a lowland tropical wet forest site in Costa Rica. Ten of the species. examined emitted substantial quantities of isoprene. These species accounted for 35-50% of the total bas...

  5. 78 FR 24990 - Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound Emission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-29

    ...EPA is approving into the Ohio State Implementation Plan (SIP), several volatile organic compound (VOC) rules that were submitted by the Ohio Environmental Protection Agency (Ohio EPA) on June 1, 2011. These rules, which include the source categories covered by the Control Technique Guideline (CTG) documents issued in 2008, as well as several other miscellaneous rule revisions, will help......

  6. KINETICS AND SELECTIVITY OF DEEP CATALYTIC OXIDATION OF VOLATILE ORGANIC COMPOUND MIXTURES

    EPA Science Inventory

    The paper gives results of a fundamental study of low-temperature deep (complete) oxidation of n-hexane, benzene, and ethyl-acetate over a 0.1% Pt, 3% Ni/gamma-AL203 catalyst. (NOTE: Deep catalytic combustion of volatile organic compounds--VOCs--is emerging as an important emissi...

  7. Spatial Gradients and Source Apportionment of Volatile Organic Compounds Near Roadways

    EPA Science Inventory

    Concentrations of 55 volatile organic compounds (VOCs) are reported near a highway in Raleigh, NC (traffic volume of approximately 125,000 vehicles/day). Levels of VOCs generally decreased exponentially with perpendicular distance from the roadway 10-100m). The EPA Chemical Mass ...

  8. INFLUENCE OF DIETARY METHIONINE SOURCE ON VOLATILE SULFUR COMPOUNDS IN BROILER EXCRETA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the impact of methionine source on volatile sulfur compounds in broiler excreta a trial was conducted using straight run broiler chicks raised in battery cages. Chicks were randomly distributed into 3 replications of 5 treatment groups with 16 birds per pen. The treatment groups were d...

  9. Identification of volatile compounds from a food-grade vinegar attractive to house flies (Diptera: Muscidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report our recent findings on the identification of volatile compounds released from the ChiangKiang vinegar that is attractive to house flies, Musca domestica. The field trapping experiments showed that the traps baited with 50-ml of the vinegar captured the highest house flies in the diary farm...

  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. NON-POLAR VOLATILE ORGANIC COMPOUNDS IN WHOLE AIR SAMPLES FROM THE AUTOEX STUDIES

    EPA Science Inventory

    Air samples were captured in SUMMA polished stainless steel canisters and returned to the laboratory for analysis of trace level volatile organic compounds by gas chromatography - mass spectrometry. ampling was performed over 2-hour periods at various distances from heavily trave...

  12. Beer volatile compounds and their application to low-malt beer fermentation.

    PubMed

    Kobayashi, Michiko; Shimizu, Hiroshi; Shioya, Suteaki

    2008-10-01

    Low-malt beers, in which the amount of wort is adjusted to less than two-thirds of that in regular beer, are popular in the Japanese market because the flavor of low-malt beer is similar to that of regular beer but the price lesser than that of regular beer. There are few published articles about low-malt beer. However, in the production process, there are many similarities between low-malt and regular beer, e.g., the yeast used in low-malt beer fermentation is the same as that used for regular beer. Furthermore, many investigations into regular beer are applicable to low-malt beer production. In this review, we focus on production of volatile compounds, and various studies that are applicable to regular and low-malt beer. In particular, information about metabolism of volatile compounds in yeast cells during fermentation, volatile compound measurement and estimation methods, and control of volatile compound production are discussed in this review, which concentrates on studies published in the last 5-6 years. PMID:19000606

  13. Spatial analysis of volatile organic compounds in South Philadelphia using passive samplers

    EPA Science Inventory

    Select volatile organic compounds (VOCs) were measured in the vicinity of a petroleum refinery and related operations in South Philadelphia, Pennsylvania, USA, using passive air sampling and laboratory analysis methods. Two-week, time-integrated samplers were deployed at 17 sites...

  14. Allelochemical effects of volatile compounds from Muscodor yucatanensis, an endophytic fungus from Bursera simaruba

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Muscodor yucatanensis, a recently described endophytic fungus, was isolated from the leaves of Bursera simaruba. In the present study we tested in vitro the mixture of volatile organic compounds (VOCs) produced by M. yucatanensis for the allelochemical effects against phytopathogenic fungi and fungo...

  15. Volatile Organic Sulfur Compounds of Environmental Interest: Dimethyl Sulfide and Methanethiol

    ERIC Educational Resources Information Center

    Chasteen, Thomas G.; Bentley, Ronald

    2004-01-01

    Volatile organic sulfur compounds (VOSCs) have been assigned environmental roles in global warming, acid precipitation, and cloud formation where two important members dimethyl sulfide (CH3)2 S, DMS, and methanethiol, CH3SH, MT, of VOSC group are involved.

  16. Characterizing and mitigating emissions of volatile organic compounds from animal feeding operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile organic compounds (VOC) emitted from animal feeding operations negatively impact local and potentially regional air quality though the release of both odorous and ozone precursor molecules. Characterizing emissions of VOCs from AFOs is strongly influenced by both the method and location of ...

  17. EMISSION OF VOLATILE ORGANIC COMPOUNDS FROM DRUM-MIX ASPHALT PLANTS

    EPA Science Inventory

    This research program was undertaken in order to develop a quantitative estimate of the emission of volatile organic compounds (VOCs) from drum-mix asphalt plants. The study was carried out by field sampling of five drum-mix plants under a variety of operating conditions. Include...

  18. SUPERCRITICAL FLUID EXTRACTION OF SEMI-VOLATILE ORGANIC COMPOUNDS FROM PARTICLES

    EPA Science Inventory

    A nitrogen oxide flux chamber was modified to measure the flux of semi-volatile organic compounds (SVOCs). Part of the modification involved the development of methods to extract SVOCs from polyurethane foam (PUF), sand, and soil. Breakthroughs and extraction efficiencies were ...

  19. SEPARATION AND ISOLATION OF VOLATILE ORGANIC COMPOUNDS USING VACUUM DISTILLATION WITH GC/MS DETERMINATION

    EPA Science Inventory

    Vacuum distillation of water, soil, oil, and fish samples is presented as an alternative technique for determining volatile organic compounds (VOCs). Analyses of samples containing VOCs and non-VOCs at 50ppb concentrations were performed to evaluate method limitations. Analyte re...

  20. IDENTIFICATION OF POLAR VOLATILE ORGANIC COMPOUNDS IN CONSUMER PRODUCTS AND COMMON MICROENVIRONMENTS

    EPA Science Inventory

    Polar volatile organic compounds were identified in the headspace of 31 fragrance products such as perfumes, colognes and soaps. About 150 different chemicals were identified in a semiquantitative fashion, using two methods to analyze the headspace: direct injection into a gas ch...