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1

Volatile fatty acid cycling in organic-rich marine sediments  

Microsoft Academic Search

Volatile fatty acid (VFA) apparent turnover rates were determined by measuring whole sediment VFA concentrations and the corresponding reaction rate constants. The following ranges of VFA concentrations were measured in Cape Lookout Bight, N.C. sediments ( molel s -1 ): acetate 54-660, propionate 1-24, butyrate <0.5-22, iso-butyrate <0.5-6. Apparent turnover rates measured over a one-year period ranged from 18-600 molel

Francis J. Sansone; Christopher S. Martens

1982-01-01

2

Organic Acids and Volatile Flavor Components Evolved During Refrigerated Storage of Kefir1  

Microsoft Academic Search

Kefir samples were prepared and transferred to ster- ile jars for storage at 4C. After 0, 7, 14, and 21 d of storage, the pH, organic acid, and volatile flavor compo- nent content were determined to monitor possible flavor changes during storage. Stored samples were analyzed for organic acid (orotic, citric, pyruvic, lactic, uric, ace- tic, propionic, butyric, and hippuric)

Z. Guzel-Seydim; A. C. Seydim; A. K. Greene

2000-01-01

3

Variation of Volatile Organic Acids in Spirits during Storage at Low and Room Temperatures  

Microsoft Academic Search

The volatile organic acids are formed during storage of the spirit under inadequate conditions and their presence in the marc distillate has a negative influence on its sensorial characteristics. The object of refining marc distillates is to improve their sensorial characteristics. In this study, this process was carried out on a distillate of grape pomace that was maintained for 7

Sandra C. Diguez; Lourdes D. D??az; M. Luisa; G. De La Pea; Esperanza F. Gmez

2002-01-01

4

Poly(L-aspartic acid) derivative soluble in a volatile organic solvent for biomedical application.  

PubMed

In order to develop a novel functional poly(L-amino acid) that can dissolve in volatile organic solvents, we prepared poly[L-aspartic acid-g-(3-diethylaminopropyl)]-b-poly(ethylene glycol) [poly(L-Asp-g-DEAP)-b-PEG] via the conjugation of 3-diethylaminopropyl (DEAP) to carboxylate groups of poly(L-Asp) (M(n) 4 K)-b-PEG (M(n) 2 K). This poly(L-aspartic acid) derivative evidenced a relatively high solubility in volatile organic solvents such as dichloromethane, chloroform, and acetone. We fabricated a model nanostructure (i.e., polymeric micelle) using poly(L-Asp-g-DEAP)-b-PEG by the film rehydration method, which involves the simple removal of the volatile organic solvent (dichloromethane) used to dissolve polymer, reducing concerns about organic solvents remaining in a nano-sized particle. Interestingly, this micelle showed the pH-stimulated release of encapsulated model drug [i.e., doxorubicin (DOX)] due to the protonation of DEAP according to the pH of the solution. We expect that this poly(L-aspartic acid) derivative promises to provide pharmaceutical potential for constituting a new stimuli-sensitive drug carrier for various drug molecules. PMID:22609602

Oh, Nam Muk; Oh, Kyung Taek; Youn, Yu Seok; Lee, Eun Seong

2012-04-27

5

Organic Acids and Volatile Organic Compounds Produced During Traditional and Starter Culture Fermentation of Bushera, a Ugandan Fermented Cereal Beverage  

Microsoft Academic Search

Starter cultures of lactic acid bacteria (Lactobacillus fermentum MINF99, Weissella confusa MINF8, Lactobacillus plantarum MINF277, Lactobacillus brevis MINF226, and Lactobacillus paracasei subsp paracasei MINF98) were used to ferment Bushera during fermentation (96 h). Organic acids and volatile compounds produced during starter and natural fermentation were investigated. Microbial counts, pH, and sugars were also determined. LAB counts increased from 5.87

C. M. B. K. Muyanja; J. A. Narvhus; T. Langsrud

2012-01-01

6

Production of hydrogen and volatile fatty acid by Enterobacter sp. T4384 using organic waste materials.  

PubMed

In a study of hydrogen-producing bacteria, strain T4384 was isolated from rice field samples in the Republic of Korea. The isolate was identified as Enterobacter sp. T4384 by phylogenetic analysis of 16S rRNA and rpoB gene sequences. Enterobacter sp. T4384 grew at a temperature range of 10-45 degrees C and at an initial pH range of 4.5-9.5. Strain T4384 produced hydrogen at 0-6% NaCl by using glucose, fructose, and mannose. In serum bottle cultures using a complete medium, Enterobacter sp. T4384 produced 1,098 ml/l H2, 4.0 g/l ethanol, and 1.0 g/l acetic acid. In a pH-regulated jar fermenter culture with the biogas removed, 2,202 ml/l H2, 6.2 g/l ethanol, and 1.0 g/l acetic acid were produced, and the lag-phase time was 4.8 h. Strain T4384 metabolized the hydrolysate of organic waste for the production of hydrogen and volatile fatty acid. The strain T4384 produced 947 ml/l H2, 3.2 g/l ethanol, and 0.2 g/l acetic acid from 6% (w/v) food waste hydrolysate; 738 ml/l H2, 4.2 g/l ethanol, and 0.8 g/l acetic acid from Miscanthus sinensis hydrolysate; and 805 ml/l H2, 5.0 g/l ethanol, and 0.7 g/l acetic acid from Sorghum bicolor hydrolysate. PMID:23412061

Kim, Byung-Chun; Deshpande, Tushar R; Chun, Jongsik; Yi, Sung Chul; Kim, Hyunook; Um, Youngsoon; Sang, Byoung-In

2013-02-01

7

Measurements of Volatile Organic Compounds and Gaseous Sulfuric Acid During the 2008 CAREBEIJING Campaign  

NASA Astrophysics Data System (ADS)

Air quality in Beijing has been a hot topic recently, because Beijing hosted the 2008 summer Olympics. To combat the problem, China ordered numerous factories shut down or used only sporadically during the games to limit air pollution in the area. Another major step involved ordering about one-half of the city's 3.3 million vehicles off the road during the games, allowing only cars on roads with odd or even-numbered license plates on alternate days until the games were over. In addition, China has implemented new auto emission standards since March 2009 with regulations that are similar to those used throughout Europe. Our team at the Texas A&M participated in the 2008 CAREBEIJING campaign, with the objectives of studying the complex chemistry of the air in Beijing, looking at emission controls and their effectiveness, studying the surrounding air from other regions and how it can affect Beijing's air, and comparing all of our findings with air quality in other cities we have examined, such as Mexico City and Houston. In this talk, preliminary results of measurements of volatile organic compounds (VOCs) and gaseous sulfuric acid will be presented to discuss the trends of VOCs and new particle formation associated with the traffic control.

Zhang, R.; Zheng, J.; Hu, M.; Zhu, T.

2009-05-01

8

Residential wood burning in an Alpine valley as a source for oxygenated volatile organic compounds, hydrocarbons and organic acids  

NASA Astrophysics Data System (ADS)

During a 3-week campaign in November/December 2005, 21 selected oxygenated volatile organic compounds (OVOCs), 19 non-methane hydrocarbons (NMHCs) and 11 low molecular weight organic acids were measured in Roveredo, a village in the Mesolcina valley in Southern Switzerland. In this region, the majority of the houses are heated with wood and the particulate matter is dominated by residential wood burning emissions. Markers in the aerosol mass spectra and carbon monoxide (CO) were used as indicators of domestic wood combustion while nitrogen oxides (NO x) were used as tracers for traffic emissions. The main source for most of the OVOCs, NMHCs and acids in this valley was assessed to be residential wood burning, except for trimethylbenzene (TMB), methylbutenol (MBO) and isopropanol. Comparisons for the NMHCs and OVOCs were made with measurements in Zrich, the largest city in Switzerland. These comparisons indicate that especially methanol, 1,3-butadiene, acrolein, methacrolein, methylacetate and methyl vinyl ketone (MVK) were strongly enhanced in Roveredo due to residential wood burning. The carcinogenic substance 1,3-butadiene shows higher concentrations in Roveredo than in Zrich, while benzene concentrations are similar at both locations. We provide a compilation of the VOC/CO ratios of the domestic wood burning dominated VOCs at Roveredo and a comparison to previously published emission ratios from wood stove studies.

Gaeggeler, Kathrin; Prevot, Andre S. H.; Dommen, Josef; Legreid, Geir; Reimann, Stefan; Baltensperger, Urs

9

Formation of short chain volatile organic acids in the automated AOM method  

Microsoft Academic Search

The end point in the automated AOM stability test for fats is related to the rapid production of volatile acids at the end\\u000a of the induction period and usually measured by conductivity of an aqueous solution of the exit gases. It has been postulated\\u000a that the reaction involves the transitory presence of a diperoxide which decomposes into two aldehydes and

J. M. deMan; Fan Tie; L. deMan

1987-01-01

10

A rapid gas chromatographic method for direct determination of short-chain (C 2C 12) volatile organic acids in foods  

Microsoft Academic Search

A simple, rapid and accurate GC analytical method for direct quantification of short-chain volatile organic acids in liquid foods was established. Hydrophilic 1,3-butanediol was selected as the internal standard. Thirteen volatile organic acids including acetic, propionic, isobutyric, butyric, isovaleric, valeric, caproic, heptanoic, caprylic, capric, lauric, lactic and levulinic acids were simultaneously determined with detection limits 0.0251 ng . The recovery

Ming-Hua Yang; Youk-Meng Choong

2001-01-01

11

Effects of acid washing treatment on the adsorption equilibrium of volatile organic compounds on titanate nanotubes  

Microsoft Academic Search

Gravimetric techniques were employed to determine the adsorption capacities of titanate nanotubes (TNT) for volatile organic compounds (VOC), including n-hexane, benzene, toluene, p-xylene, m-xylene, and o-xylene, at isothermal conditions of 15, 20 and 25C. TNT were prepared via a hydrothermal treatment of TiO2 powders in a 10M NaOH solution at 150C for 24h, and subsequently washed with HCl aqueous solution

Chung-Kung Lee; Huang-Chi Chen; Shin-Shou Liu; Fu-Chuang Huang

2010-01-01

12

Analysis of Volatile Organic Compounds.  

National Technical Information Service (NTIS)

An improved system is described for reproducibly analyzing, both qualitatively and quantitatively, trace amounts of a large number of organic volatiles existing in a gas sample. Applications include: (1) analyzing the headspace gas of body fluids and comp...

A. Zlatkis

1974-01-01

13

Volatile organic acid adsorption and cation dissociation by porphyritic andesite for enhancing hydrolysis and acidogenesis of solid food wastes.  

PubMed

Volatile organic acid adsorption, cation dissociation by porphyritic andesite, and their effects on the hydrolysis and acidogenesis of solid food wastes were evaluated through batch experiments. The acetic acid adsorption experiments show that pH was mainly regulated by H(+) adsorption. The mono-layer and multi-layer adsorption were found under the low (8.3-83.2 mmol/L) and high (133.22-532.89 mmol/L) initial acetic acid concentration, respectively. The dissociated cations concentration in acidic solution showed the predominance of Ca(2+). Porphyritic andesite addition elevated the pH levels and accelerated hydrolysis and acidogenesis in the batch fermentation experiment. Leachate of porphyritic andesite addition achieved the highest hydrolysis constant of 22.1 x 10(-3)kgm(-2)d(-1) and VS degradation rates of 3.9 g L(-1)d(-1). The highest activity of microorganisms represented by specific growth rate of ATP, 0.16d(-1), and specific consumption rate of Ca(2+), 0.18d(-1), was obtained by adding leachate of porphyritic andesite. PMID:20156676

Cheng, Fan; Li, Ming; Li, Dawei; Chen, Ling; Jiang, Weizhong; Kitamura, Yutaka; Li, Baoming

2010-02-13

14

Milk volatile organic compounds and fatty acid profile in cows fed timothy as hay, pasture, or silage.  

PubMed

Nutrient composition and organoleptic properties of milk can be influenced by cow diets. The objective of this study was to evaluate the forage type effects on volatile organic compounds, fatty acid (FA) profile, and organoleptic properties of milk. Timothy grass was fed as hay, pasture, or silage during a period of 27 d to a group of 21 cows in a complete block design based on days in milk. Each cow also received 7.2kg/d of a concentrate mix to meet their nutrient requirements. Forage dry matter intake averaged 13.9kg/d and was not different among treatments. Milk yield was higher for cows fed pasture, intermediate for cows fed silage, and lowest for cows fed hay. However, milk fat content was higher for cows fed hay and silage, compared with cows fed pasture. As a result, fat-corrected milk and fat yield were not different among treatments. Increasing the supply of dietary cis-9,cis-12 18:2 (linoleic acid) and cis-9,cis-12,cis-15 18:3 (?-linolenic acid) when feeding pasture enhanced the concentration of these 2 essential FA in milk fat compared with feeding hay or silage. Moreover, the ratio of 16:0 (palmitic acid) to cis-9 18:1 (oleic acid), which is closely related to the melting properties of milk fat, was lower in milk from cows on pasture than in milk from cows fed hay or silage. Cows fed hay produced milk with higher levels of several free FA and ?-lactones, but less pentanal and 1-pentanol. More dimethyl sulfone and toluene were found in milk of cows on pasture. Cows fed silage produced milk with higher levels of acetone, 2-butanone, and ?-pinene. Results from a sensory evaluation showed that panelists could not detect a difference in flavor between milk from cows fed hay compared with silage. However, a significant number of assessors perceived a difference between milk from cows fed hay compared with milk from cows fed pasture. In a sensory ranking test, the percentage of assessors ranking for the intensity of total (raw milk, fresh milk, and farm milk), sweet (empyreumatic, vanilla, caramel, and sugar), and grassy (grass, leafy vegetable, and plant) flavors was higher for milk from cows fed pasture compared with hay and silage. Using timothy hay, pasture, or silage harvested at a similar stage of development, the current study shows that the taste of milk is affected by the forage type fed to cows. More research is, however, needed to establish a link between the sensory attributes of milk and the observed changes in volatile organic compounds and FA profile. PMID:24035021

Villeneuve, M-P; Lebeuf, Y; Gervais, R; Tremblay, G F; Vuillemard, J C; Fortin, J; Chouinard, P Y

2013-09-12

15

VOLATILIZATION OF ORGANIC POLLUTANTS FROM WATER  

EPA Science Inventory

The volatilization of organic environmental contaminants from water bodies to the atmosphere was investigated. The general aim was to elucidate the factors that control the volatilization process and develop predictive methods for calculating volatilization rates for various comp...

16

SCREENING FOR VOLATILE ORGANIC FATTY ACIDS IN AGRICULTURAL AIR USING SOLID-PHASE MICROEXTRACTION AND GAS CHROMATOGRAPHY-MASS SPECTROMETRY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Volatile fatty acids (VFAs) are a major component of odorous gases associated with agricultural sources. Because of typically low VFA air concentrations, conventional air sampling methods including sorbent tubes and vacuum canisters are often not sensitive enough to detect them. Solid phase microe...

17

In situ direct measurement of vapor pressures and thermodynamic parameters of volatile organic materials in the vapor phase: benzoic acid, ferrocene, and naphthalene.  

PubMed

We report the direct determination of vapor pressures and optical and thermodynamic parameters of powders of low-volatile materials in their vapor phase using a commercial UV/Vis spectrometer. This methodology is based on the linear proportionality between the density of the saturated gas of the material and the absorbance of the gas at different temperatures. The vapor pressure values determined for benzoic acid and ferrocene are in good agreement with those reported in the literature with ?2-7?% uncertainty. Thermodynamic parameters of benzoic acid, ferrocene, and naphthalene are determined in situ at temperatures below their melting points. The sublimation enthalpies of the investigated organic molecules are in excellent agreement with the ICTAC recommended values (less than 1?% difference). This method has been used to measure vapor pressures and thermodynamic parameters of organic volatile materials with vapor pressures of ?0.5-355 Pa in the 50-100?C temperature range. PMID:23606455

Hikal, Walid M; Weeks, Brandon L

2013-04-19

18

Volatilization of Organic Pollutants from Water.  

National Technical Information Service (NTIS)

The volatilization of organic environmental contaminants from water bodies to the atmosphere was investigated. The general aim was to elucidate the factors that control the volatilization process and develop predictive methods for calculating volatilizati...

A. Bobra D. Mackay E. Chau J. Billington W. Yang Shiu

1982-01-01

19

Regeneration of carboxylic acid-laden basic sorbents by leaching with a volatile base in an organic solvent  

DOEpatents

Carboxylic acids are sorbed from aqueous feedstocks onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with an organic solution of alkylamine thus forming an alkylamine/carboxylic acid complex which is decomposed with improved efficiency to the desired carboxylic acid and the alkylamine. Carbon dioxide addition can be used to improve the adsorption or the carboxylic acids by the solid phase sorbent.

King, C. Judson (Kensington, CA); Husson, Scott M. (Berkeley, CA)

1999-01-01

20

Low volatile organic compound paints  

SciTech Connect

Increasingly stringent air emission standards in various states has dictated the elimination of engineering finishes which are derived from high volatile organic compound (VOC) paint chemistries. In July 1989, Allied-Signal, Inc., Kansas City Division, Kansas City, Missouri, voluntarily closed its paint facility, due to non-compliance with local air emission standards. The following details the materials selection and evaluations which led to current processing using low VOC paints, which permitted the Allied Signal, Inc., paint facility to achieve compliance and resume operations. 1 tab.

Martinez, F.E.

1991-01-01

21

THEORETICAL EVALUATION OF STABILITY OF VOLATILE ORGANIC CHEMICALS AND POLAR VOLATILE ORGANIC CHEMICALS IN CANISTERS  

EPA Science Inventory

A mathematical model was developed for describing loss by physical adsorption of volatile organic chemicals (VOCs) and polar volatile organic chemicals (PVOCs) in stainless steel canisters. he model incorporates compound specific properties such as polarizability, vapor concentra...

22

SEMI-VOLATILE ORGANIC ACIDS AND OTHER POLAR COMPOUNDS COLLECTED IN NEW YORK CITY IN RESPONSE TO THE EVENTS OF 9/11  

EPA Science Inventory

Concentrations of over 25 polar semi-volatile and non-volatile organic compounds were measured in Lower Manhattan, New York using a high capacity Integrated Organic Gas and Particle sampler, after the initial destruction of the World Trade Center. The polar organic compounds in...

23

Volatile Organic Compounds in Uremia  

PubMed Central

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 1059 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 1059 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.

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

2012-01-01

24

Organic Aerosols: A Potential Source of Oxygenated Volatile Organic Compounds  

NASA Astrophysics Data System (ADS)

Numerous laboratory studies have demonstrated that organic surfaces are readily oxidized by O3 and OH, in many cases producing oxygenated volatile organic compounds (OVOC) such as aldehydes and organic acids. Because many aerosols possess organic coatings, it is possible that oxidation of organic aerosol surfaces could provide a significant flux of OVOC into the troposphere that is not accounted for in current models. From data collected on the NASA DC-8 during INTEX-NA over North America in the summer of 2004 (part of ICARTT -- the International Consortium for Atmospheric Research on Transport and Transformation), we estimate the potential flux of OVOC from organic aerosol oxidation, and discuss its implications for our understanding of atmospheric photochemistry.

Kwan, A. J.; Crounse, J. D.; Wennberg, P. O.

2005-12-01

25

Volatility of secondary organic aerosol during OH radical induced ageing  

NASA Astrophysics Data System (ADS)

The aim of this study was to investigate oxidation of SOA formed from ozonolysis of ?-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA) set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of KIT in Karlsruhe and at the SAPHIR chamber of FZJ in Jlich. A fresh SOA was produced from ozonolysis of ?-pinene or limonene and then aged by enhanced OH exposure. As an OH-radical source in the AIDA-chamber the ozonolysis of tetramethylethylene (TME) was used while in the SAPHIR-chamber the OH was produced by natural light photochemistry. A general feature is that SOA produced from ozonolysis of ?-pinene and limonene initially were rather volatile and becomes less volatile with time in the ozonolysis part of the experiment. Inducing OH chemistry or adding a new portion of precursors made the SOA more volatile due to addition of new semi-volatile material to the aged aerosol. The effect of OH chemistry was less pronounced in high concentration and low temperature experiments when lower relative amounts of semi-volatile material were available in the gas phase. Conclusions drawn from the changes in volatility were confirmed by comparison with the measured and modelled chemical composition of the aerosol phase. Three quantified products from the ?-pinene oxidation; pinonic acid, pinic acid and methylbutanetricarboxylic acid (MBTCA) were used to probe the processes influencing aerosol volatility. A major conclusion from the work is that the OH induced ageing can be attributed to gas phase oxidation of products produced in the primary SOA formation process and that there was no indication on significant bulk or surface reactions. The presented results, thus, strongly emphasise the importance of gas phase oxidation of semi- or intermediate-volatile organic compounds (SVOC and IVOC) for atmospheric aerosol ageing processing.

Salo, K.; Hallquist, M.; Jonsson, . M.; Saathoff, H.; Naumann, K.-H.; Spindler, C.; Tillmann, R.; Fuchs, H.; Bohn, B.; Rubach, F.; Mentel, Th. F.; Mller, L.; Reinnig, M.; Hoffmann, T.; Donahue, N. M.

2011-07-01

26

Volatility of secondary organic aerosol during OH radical induced ageing  

NASA Astrophysics Data System (ADS)

The aim of this study was to investigate oxidation of SOA formed from ozonolysis of ?-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA) set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of Karlsruhe Institute of Technology (KIT) in Karlsruhe and at the SAPHIR chamber of Forchungzentrum Jlich (FZJ) in Jlich. A fresh SOA was produced from ozonolysis of ?-pinene or limonene and then aged by enhanced OH exposure. As an OH radical source in the AIDA-chamber the ozonolysis of tetramethylethylene (TME) was used while in the SAPHIR-chamber the OH was produced by natural light photochemistry. A general feature is that SOA produced from ozonolysis of ?-pinene and limonene initially was rather volatile and becomes less volatile with time in the ozonolysis part of the experiment. Inducing OH chemistry or adding a new portion of precursors made the SOA more volatile due to addition of new semi-volatile material to the aged aerosol. The effect of OH chemistry was less pronounced in high concentration and low temperature experiments when lower relative amounts of semi-volatile material were available in the gas phase. Conclusions drawn from the changes in volatility were confirmed by comparison with the measured and modelled chemical composition of the aerosol phase. Three quantified products from the ?-pinene oxidation; pinonic acid, pinic acid and methylbutanetricarboxylic acid (MBTCA) were used to probe the processes influencing aerosol volatility. A major conclusion from the work is that the OH induced ageing can be attributed to gas phase oxidation of products produced in the primary SOA formation process and that there was no indication on significant bulk or surface reactions. The presented results, thus, strongly emphasise the importance of gas phase oxidation of semi- or intermediate-volatile organic compounds (SVOC and IVOC) for atmospheric aerosol ageing.

Salo, K.; Hallquist, M.; Jonsson, . M.; Saathoff, H.; Naumann, K.-H.; Spindler, C.; Tillmann, R.; Fuchs, H.; Bohn, B.; Rubach, F.; Mentel, Th. F.; Mller, L.; Reinnig, M.; Hoffmann, T.; Donahue, N. M.

2011-11-01

27

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...

28

VOLATILE ORGANIC SAMPLING TRAIN - SOOT INTERFERENCE REPORT  

EPA Science Inventory

The U.S. Environmental Protection Agency uses Method 0030, the Volatile Organic Sampling Train (VOST), as a tool in determining the destruction and removal efficiencies of industrial boilers co-firing hazardous waste. ecently, concerns have been expressed over possible measuremen...

29

COMPLETE CATALYTIC OXIDATION OF VOLATILE ORGANICS  

EPA Science Inventory

The paper reviews heterogeneous catalytic oxidation, focusing on its application to the control of volatile organic compounds (VOCs) at operating conditions typical of field applications. The parameters for this review are: low to moderate temperatures (25-400 C), atmospheric pre...

30

Emerging Control Technologies for Volatile Organic Compounds  

Microsoft Academic Search

Environmental problems associated with volatile organic compounds (VOCs) in the atmosphere have provided the driving force for sustained fundamental and applied research in the area of environmental remediation. Conventional methods currently used to treat VOCs include incineration, condensation, adsorption, and absorption. Incineration and condensation are cost-effective only for moderate to high VOC concentrations. Adsorption and absorption do not destroy VOCs

Geeta Rani Parmar; N. N. Rao

2008-01-01

31

Treatment of odorous volatile fatty acids using a biotrickling filter  

Microsoft Academic Search

In this study, a novel fibrous bioreactor was developed for treating odorous compounds present in contaminated air. The first stage of this work was a preliminary study which aimed at investigating the feasibility of using the fibrous bioreactor for the removal of malodorous volatile fatty acids (VFA) that is a common odorous contaminant generated from anaerobic degradation of organic compounds.

Y. F. Tsang; H. Chua; S. N. Sin; S. Y. Chan

2008-01-01

32

Volatile Organic Compounds Fibre Optic Nanosensor  

Microsoft Academic Search

A novel vapochromic material of formula (Au2Ag2(C6F5)4(C6H5N)2) has been used to develop a volatile organic compounds (VOCs) sensor. This product changes its optical properties, such as colour or refractive index, when exposed to some organic vapours. The sensor consists of a nanometer-scale Fizeau interferometer doped with the above mentioned vapochromic complex and built onto a cleaved end of a multimode

Csar Elosaa; Cndido Bariina; Ignacio R. Matas; Francisco J. Arreguia; Asuncin Luquin; Mariano Laguna; Julin Garrido

33

Influence of pulping process on the emission of formaldehyde and volatile organic acids from pulps and medium density fibreboards (MDF)  

Microsoft Academic Search

Cold water extracts from pulps produced by the chemo-thermomechanical technique (CTMP process) contain\\u000a higher amounts of formate and acetate ions compared to cold water extracts from pulps produced by the thermo-mechanical\\u000a process (TMP process). The CTMP shows ahigher emission of acetic acid than the corresponding TMP.\\u000a However, the release of formic acid is lower than that from TMP due to

Edmone Roffael; Brigitte Dix; Thomas Schneider

2007-01-01

34

40 CFR 60.582 - Standard for volatile organic compounds.  

Code of Federal Regulations, 2010 CFR

...Subpart Fff - Standards of Performance for Flexible Vinyl and Urethane] [Sec. 60.582 - Standard for volatile organic compounds...SOURCES-- Standards of Performance for Flexible Vinyl and Urethane Sec. 60.582 Standard for volatile organic...

2009-07-01

35

Secondary organic aerosols formed from oxidation of biogenic volatile organic compounds in the Sierra Nevada Mountains of California  

Microsoft Academic Search

Biogenic volatile organic compound (BVOC) emissions, such as isoprene and terpenes, can be oxidized to form less volatile carbonyls, acids, and multifunctional oxygenated products that may condense to form secondary organic aerosols (SOA). This research was designed to assess the contribution of oxidized BVOC emissions to SOA in coniferous forests by collecting high-volume particulate samples for 6 days and 5

Thomas M. Cahill; Vincent Y. Seaman; M. Judith Charles; Rupert Holzinger; Allen H. Goldstein

2006-01-01

36

Gas chromatography coupled to mass spectrometry analysis of volatiles, sugars, organic acids and aminoacids in Valencia Late orange juice and reliability of the Automated Mass Spectral Deconvolution and Identification System for their automatic identification and quantification.  

PubMed

Neutral volatiles and non-volatile polar compounds (sugars, organics acids and aminoacids) present in Valencia Late orange juice have been analysed by Gas Chromatography coupled to Mass Spectrometry (GC-MS). Before analysis, the neutral volatiles have been extracted by Headspace-Solid Phase Microextraction (HS-SPME), and the non-volatile polar compounds have been transformed to their corresponding volatile trimethylsilyl (TMS) derivatives. From the resulting raw GC-MS data files, the reliability of the Automated Mass Spectral Deconvolution and Identification System (AMDIS) to perform accurate identification and quantification of the compounds present in the sample has been tested. Hence, both raw GC-MS data files have been processed automatically by using AMDIS and manually by using Xcalibur, the manufacturer's data processing software for the GC-MS platform used. Results indicate that the reliability of AMDIS for accurate identification and quantification of the compounds present in the sample strongly depends on a number of operational settings, for both the MS and AMDIS, which must be optimized for the particular type of assayed sample. After optimization of these settings, AMDIS and Xcalibur yield practically the same results. A total of 85 volatiles and 22 polar compounds have been identified and quantified in Valencia Late orange juice. PMID:22533907

Cerdn-Calero, Manuela; Sendra, Jos Mara; Sentandreu, Enrique

2012-04-11

37

Volatile organic compounds (VOCs) in soils  

Microsoft Academic Search

Soils may act as sources or sinks of volatile organic compounds (VOCs). Many of the formed VOCs are produced by microorganisms,\\u000a and it would be a challenge to investigate soil microbial communities by studying their VOC profile. Such volatilomics would\\u000a have the advantage of avoiding extraction steps that are often a limit in genomic or proteomic approaches. Abundant literature\\u000a on

Heribert Insam; Martin S. A. Seewald

2010-01-01

38

TMVOC, simulator for multiple volatile organic chemicals  

SciTech Connect

TMVOC is a numerical simulator for three-phase non-isothermal flow of water, soil gas, and a multicomponent mixture of volatile organic chemicals (VOCs) in multidimensional heterogeneous porous media. It is an extension of the TOUGH2 general-purpose simulation program developed at the Lawrence Berkeley National Laboratory. TMVOC is designed for applications to contamination problems that involve hydrocarbon fuel or organic solvent spills in saturated and unsaturated zones. It can model contaminant behavior under ''natural'' environmental conditions, as well as for engineered systems, such as soil vapor extraction, groundwater pumping, or steam-assisted source remediation. TMVOC is upwards compatible with T2VOC (Falta et al., 1995) and can be initialized from T2VOC-style initial conditions. The main enhancements in TMVOC relative to T2VOC are as follows: a multicomponent mixture of volatile organic chemicals can be modeled; any and all combinations of the three phases water-oil-gas are treated; several non-condensible gases may be present; diffusion is treated in all phases in a manner that is fully coupled with phase partitioning. This paper gives a brief summary of the methodology used in TMVOC as well as highlighting some implementation issues. Simulation of a NAPL spill and subsequent remediation is discussed for a 2-D vertical section of a saturated-unsaturated flow problem.

Pruess, Karsten; Battistelli, Alfredo

2003-03-25

39

Volatile organic carbon/air separation test using gas membranes  

SciTech Connect

An estimated 900 metric tons of carbon tetrachloride were discharged to soil columns during the Plutonium Finishing Plant Operations at the Hanford Site. The largest percentage of this volatile organic compound was found in the vadose region of the 200 West Area. Using a Vacuum Extraction System, the volatile organic compound was drawn from the soil in an air mixture at a concentration of about 1,000 parts per million. The volatile organic compounds were absorbed from the air stream using granulated activated carbon canisters. A gas membrane separation system, developed by Membrane Technology and Research, Inc., was tested at the Vacuum Extraction System site to determine if the volatile organic compound load on the granulated activated carbon could be reduced. The Vacuum Extraction System condensed most of the volatile organic compound into liquid carbon tetrachloride and vented the residual gas stream into the granulated activated carbon. This system reduced the cost of operation about $5/kilogram of volatile organic compound removed.

King, C.V.; Kaschemekat, J.

1993-08-01

40

Volatile Organic Compound Emissions from Dairy Facilities in Central California  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

41

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS  

SciTech Connect

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.

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

2002-06-01

42

Volatile Organic Compound Emissions by Agricultural Crops  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

43

Aldol Condensation of Volatile Carbonyl Compounds in Acidic Aerosols  

NASA Astrophysics Data System (ADS)

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.

Noziere, B.; Esteve, W.

2003-12-01

44

21 CFR 573.914 - Salts of volatile fatty acids.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Salts of volatile fatty acids. 573.914... Food Additive Listing § 573.914 Salts of volatile fatty acids. (a) Identity...blend containing the ammonium or calcium salt of isobutyric acid and the ammonium...

2013-04-01

45

COMPARISON OF AMBIENT AIR SAMPLING TECHNIQUES FOR VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

A series of fourteen experimental sampling runs were carried out at a field site to collect data from several ambient air monitoring methods for volatile organic compounds (VOCs). Ambient air was drawn through a sampling manifold and was continuously spiked with volatile organic ...

46

40 CFR 60.462 - Standards for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.462 Section 60.462 Protection of Environment...Coil Surface Coating § 60.462 Standards for volatile organic compounds. (a) On and after the date on which §...

2013-07-01

47

40 CFR 60.492 - Standards for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection of Environment...Surface Coating Industry § 60.492 Standards for volatile organic compounds. On or after the date on which the...

2013-07-01

48

40 CFR 60.602 - Standard for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.602 Section 60.602 Protection of Environment...Production Facilities § 60.602 Standard for volatile organic compounds. On and after the date on which the...

2013-07-01

49

40 CFR 60.432 - Standard for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.432 Section 60.432 Protection of Environment...Publication Rotogravure Printing § 60.432 Standard for volatile organic compounds. During the period of the performance test...

2013-07-01

50

40 CFR 60.392 - Standards for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.392 Section 60.392 Protection of Environment...Surface Coating Operations § 60.392 Standards for volatile organic compounds. On and after the date on which the...

2013-07-01

51

40 CFR 60.712 - Standards for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.712 Section 60.712 Protection of Environment...Tape Coating Facilities § 60.712 Standards for volatile organic compounds. Each owner or operator of any...

2013-07-01

52

40 CFR 60.452 - Standard for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.452 Section 60.452 Protection of Environment...Coating: Large Appliances § 60.452 Standard for volatile organic compounds. On or after the date on which the...

2013-07-01

53

40 CFR 60.742 - Standards for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection of Environment...Substrates Facilities § 60.742 Standards for volatile organic compounds. (a) Each owner or operator of an...

2013-07-01

54

40 CFR 60.442 - Standard for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection of Environment...Surface Coating Operations § 60.442 Standard for volatile organic compounds. (a) On and after the date on which the...

2013-07-01

55

40 CFR 60.582 - Standard for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standard for volatile organic compounds. 60.582 Section 60.582 Protection of Environment...Urethane Coating and Printing § 60.582 Standard for volatile organic compounds. (a) On and after the date on which the...

2013-07-01

56

40 CFR 60.622 - Standards for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection of Environment...Petroleum Dry Cleaners § 60.622 Standards for volatile organic compounds. (a) Each affected petroleum solvent...

2013-07-01

57

SOIL SAMPLE COLLECTION AND HANDLING FOR VOLATILE ORGANICS ANALYSIS  

EPA Science Inventory

The guidance document will detail the Region I EPA New England requirements for the collection of soil samples for volatile organics analysis by SW-846, Method 5035. The guidance will describe the project planning process for the collection of soil samples for volatile organics ...

58

BIOCONCENTRATION FACTORS FOR VOLATILE ORGANIC COMPOUNDS IN VEGETATION  

EPA Science Inventory

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

59

DYNAMIC ANALYSIS OF SORPTION OF VOLATILE ORGANIC COMPOUNDS IN WATER  

Microsoft Academic Search

Chlorinated and brominated volatile organic compounds are among the groundwater pollutants creating major environmental problems. In this study, dynamic behavior of certain volatile organic compounds in water was investigated by using a novel moment technique. Adsorption equilibrium constant and the penetration length of tracers were evaluated by the first absolute and the second central moment expressions derived for a pulse-response

Nail Yasyerli; Ugur Harbili

2008-01-01

60

Formation of volatile chemicals from thermal degradation of less volatile coffee components: quinic acid, caffeic acid, and chlorogenic acid.  

PubMed

The less volatile constituents of coffee beans (quinic acid, caffeic acid, and chlorogenic acid) were roasted under a stream of nitrogen, air, or helium. The volatile degradation compounds formed were analyzed by gas chromatography and gas chromatography-mass spectrometry. Caffeic acid produced the greatest amount of total volatiles. Quinic acid and chlorogenic acid produced a greater number of volatiles under the nitrogen stream than under the air stream. These results suggest that the presence of oxygen does not play an important role in the formation of volatile compounds by the heat degradation of these chemicals. 2,5-Dimethylfuran formed in relatively large amounts (59.8-2231.0 microg/g) in the samples obtained from quinic acid and chlorogenic acid but was not found in the samples from caffeic acid. Furfuryl alcohol was found in the quinic acid (259.9 microg/g) and caffeic acid (174.4 microg/g) samples roasted under a nitrogen stream but not in the chlorogenic sample. The three acids used in the present study do not contain a nitrogen atom, yet nitrogen-containing heterocyclic compounds, pyridine, pyrrole, and pyrazines, were recovered. Phenol and its derivatives were identified in the largest quantities. The amounts of total phenols ranged from 60.6 microg/g (quinic acid under helium) to 89893.7 microg/g (caffeic acid under helium). It was proposed that phenol was formed mainly from quinic acid and that catechols were formed from caffeic acid. Formation of catechol from caffeic acid under anaerobic condition indicates that the reaction participating in catechol formation was not oxidative degradation. PMID:20405916

Moon, Joon-Kwan; Shibamoto, Takayuki

2010-05-12

61

Control of postharvest Botrytis fruit rot of strawberry by volatile organic compounds of Candida intermedia.  

PubMed

A study was conducted to identify volatile organic compounds or volatiles produced by Candida intermedia strain C410 using gas chromatography-mass spectrometry, and to determine efficacy of the volatiles of C. intermedia in suppression of conidial germination and mycelial growth of Botrytis cinerea and control of Botrytis fruit rot of strawberry. Results showed that, among 49 volatiles (esters, alcohols, alkenes, alkanes, alkynes, organic acids, ketones, and aldehydes) identified from C. intermedia cultures on yeast extract peptone dextrose agar, two compounds, 1,3,5,7-cyclooctatetraene and 3-methyl-1-butanol, were the most abundant. Synthetic chemicals of 1,3,5,7-cyclooctatetraene; 3-methyl-1-butanol; 2-nonanone; pentanoic acid, 4-methyl-, ethyl ester; 3-methyl-1-butanol, acetate; acetic acid, pentyl ester; and hexanoic acid, ethyl ester were highly inhibitory to conidial germination and mycelial growth of B. cinerea. Inhibition of conidial germination and mycelial growth of B. cinerea by volatiles of C. intermedia was also observed. Meanwhile, results showed that incidence and severity of Botrytis fruit rot of strawberry was significantly (P < 0.01) reduced by exposure of the strawberry fruit to the volatiles from C. intermedia cultures or C. intermedia-infested strawberry fruit. These results suggest that the volatiles of C. intermedia C410 are promising biofumigants for control of Botrytis fruit rot of strawberry. PMID:21323467

Huang, R; Li, G Q; Zhang, J; Yang, L; Che, H J; Jiang, D H; Huang, H C

2011-07-01

62

Volatile organic compound remedial action project  

SciTech Connect

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).

NONE

1991-12-01

63

Volatile Organic Compounds Contribute to Airway Hyperresponsiveness  

PubMed Central

Background Volatile organic compounds (VOCs) in concentrations found in both the work and home environments may influence lung function. We investigated the prevalence of airway responsiveness in workers exposed to VOCs. Methods We used allergic skin tests, nonspecific airway hyperresponsiveness testing and questionnaires to study twenty exposed workers and twenty-seven control subjects. Atopy was defined as a reactor who showed >3+ response to one or more allergens on the skin prick tests. Airway hyperresponsiveness (BRindex) was defined as log [% fall of FEV1/ log (last concentration of methacholine) +10]. Results The VOC exposed workers, in comparison with the control subjects, tended to have a higher BRindex (1.190.07 vs. 1.150.08, respectively). Workers exposed to VOCs with atopy or smoker, as compared with the workers exposed to VOCs with non-atopy and who were non-smokers and the control subjects with non-atopy and who were non-smokers, had a significantly higher BRindex (1.200.05 vs. 1.140.06 vs. 1.100.03, respectively p<0.05). The BRindex was not correlated with atopy, the smoking status or the duration of VOC exposure. Conclusions These findings suggest that VOCs may act as a contributing factor of airway hyperresponsiveness in workers exposed to VOCs.

Jang, An-Soo; Choi, Inseon-S; Koh, Young-Il

2007-01-01

64

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

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Ohio; Volatile Organic Compound Emission Control Measures for...Implementation Plan (SIP), several volatile organic compound (VOC) rules that were submitted...stationary sources, storage of volatile organic liquids, industrial cleaning...

2013-04-29

65

40 CFR 60.112b - Standard for volatile organic compounds (VOC).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standard for volatile organic compounds (VOC). 60.112b Section... Standards of Performance for Volatile Organic Liquid Storage Vessels (Including Petroleum... § 60.112b Standard for volatile organic compounds (VOC). (a) The...

2013-07-01

66

77 FR 46961 - Approval and Promulgation of Implementation Plans; Wisconsin; Volatile Organic Compound Emission...  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Wisconsin; Volatile Organic Compound Emission Control Measures for...Technology (RACT) for sources of Volatile Organic Compound (VOC) emissions in moderate...recordkeeping requirements, Volatile organic compounds. Dated: June 11, 2012....

2012-08-07

67

Radioiodine Volatilization in the Presence of Organic Compounds  

SciTech Connect

The impact of organic compounds on iodine volatility was investigated under a range of postaccident chemical conditions expected in a reactor containment structure. The rate of production of volatile iodine was evaluated in the presence of 10{sup -3} M concentrations of carbonyl, alkyl halide, and aromatic compounds. A bench-scale apparatus, installed in the irradiation chamber of a Gammacell, was used to measure the rate of iodine volatilization from 10{sup -6} to 10{sup -4} M CsI solutions with pH values from 5 to 9. The results indicated that organic compounds could be classified into groups, based on their distinct effects on iodine volatility. Iodine volatilization increased significantly, up to two orders of magnitude, in the presence of carbonyl compounds and alkyl chlorides, while it decreased in the presence of aromatic compounds. Gas phase speciation indicated that organic iodides dominate the airborne iodine species in the presence of carbonyl compounds and alkyl halides.

Taghipour, Fariborz; Evans, Greg J. [University of Toronto (Canada)

2001-05-15

68

Secondary organic aerosol from biogenic volatile organic compound mixtures  

NASA Astrophysics Data System (ADS)

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.

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

2011-04-01

69

Volatile Organic Compound Analysis in Istanbul  

NASA Astrophysics Data System (ADS)

Volatile Organic Compound Analysis in Istanbul . apraz1, 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, Ni?anta??, 34365, ?stanbul, 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 Ka??thane (Golden Horn) region in Istanbul during the winter season of 2011 in order to develop the necessary scientific framework for the subsequent developments. Ka??thane 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 compounds. N-octane, 3-methylheptane, n-nonane, 2,3,4-trimethylpentane and n-hexane parameters ranged between 3 ppbv and maximum value of 10 ppbv. The other VOC parameters are measured below 3 ppbv value. At participating urban locations for the year of data considered, levels of carbonyls were higher than the level of the other organic compound groups, suggesting that emissions from motor vehicles and photochemical reactions strongly in?uence ambient air concentrations of carbonyls. Of the most prevalent carbonyls, formaldehyde and acetaldehyde were the dominant compounds, ranging from 1.5-7.4 ppbv for formaldehyde, to 0.8-2.7 ppbv for acetaldehyde. Keywords: Air quality, Volatile Organic Compounds (VOC), industry, meteorology, urban, Ka??thane, ?stanbul. Acknowledgment: This work was part of the TUJJB-TUMEHAP-01-10 and Turkish Scientific and Technical Research Council Project No: 109Y132.

?apraz, .; Deniz, A.; ztrk, A.; Incecik, S.; Toros, H.; Co?kun, M.

2012-04-01

70

Volatile chelates and organic compounds of neptunium and plutonium  

SciTech Connect

In this review, volatile coordination and organic compounds of neptunium and plutonium are described, including complex halides, alkoxides, borohydrides, ..beta..-diketonates, phthalocyanines, and organometallic ..pi..-complexes. Comparison is made with analogous compounds of other f-elements (particularly, uranium and thorium). The prospects of practical use of volatile compounds of neptunium and plutonium are discussed.

Mishin, V.Ya.; Sidorenko, G.V.; Suglobov, D.N.

1987-01-01

71

[Emission volatile organic compounds from new textile floor coverings].  

PubMed

The emission of formaldehyde and the other volatile organic compounds (toluene, styrene, 4-PC) and total volatile organic compounds (VOCs) from new textile floor coverings was measured with the use of environmental chamber (0.6 m3 capacity) in the following conditions: temperature 23 degrees C, relative humidity 45%, 1 exchange/hour and factor loading 1 m2 m-3. The formaldehyde was determined by using colorimetric method, VOCs by GC method. The tested carpets did not emit formaldehyde. The emission of other volatile organic compounds was very low and fulfill known requirements. PMID:12621886

Igielska, Barbara; Pecka, Irena; Sitko, Elzbieta; Nikel, Grazyna; Wiglusz, Renata

2002-01-01

72

Volatilization of Organic Pollutants in Wastewater Treatment: Model Studies.  

National Technical Information Service (NTIS)

Methods are presented for simulating the transfer of volatile organic contaminants to the atmosphere during surface and bubble aeration. Suitable values of the input parameters for conditions representative of activated sludge treatment are suggested, and...

P. V. Roberts C. Munz P. Daendliker C. Matter-Mueller

1984-01-01

73

VOLATILIZATION OF ORGANIC POLLUTANTS IN WASTEWATER TREATMENT: MODEL STUDIES  

EPA Science Inventory

Methods are presented for simulating the transfer of volatile organic contaminants to the atmosphere during surface and bubble aeration. Suitable values of the input parameters for conditions representative of activated sludge treatment are suggested, and model calculations are p...

74

SEPARATION OF VOLATILE ORGANIC COMPOUNDS FROM SURFACTANT SOLUTIONS BY PERVAPORATION  

EPA Science Inventory

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

75

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 ...

76

EVALUATION OF A PASSIVE MONITOR FOR VOLATILE ORGANICS  

EPA Science Inventory

A laboratory investigation was conducted to determine the potential utility of a commercially available passive dosimeter for monitoring toxic volatile organic compounds at ambient levels. Test compounds included: chloroform, methylchloroform, carbon tetrachloride, trichloroethyl...

77

DEVELOPMENT OF OZONE REACTIVITY SCALES FOR VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

Methods for developing a numerical scale ranking reactivities of volatile organic compounds (VOCs) towards ozone formation were investigated. ffects of small VOC additions on ozone formation (incremental reactivities) were calculated for 140 types of VOCs in model scenarios repre...

78

Preparing Soil Samples for Volatile Organic Compound Analysis.  

National Technical Information Service (NTIS)

Three equilibrium headspace and three solvent extraction methods of preparing soil samples for determining volatile organic compounds (VOCs) were compared. Soil samples were spiked with five gasoline range aromatic compounds and four chlorinated compounds...

A. D. Hewitt

1997-01-01

79

Collaborative Study of Soils Spiked with Volatile Organic Compounds.  

National Technical Information Service (NTIS)

Vapor fortification is a method of spiking soils with volatile organic compounds (VOCs) that was recently developed for producing materials suitable for performance evaluation and quality assurance/quality control (QA/QC). Using this treatment method, soi...

A. D. Hewitt C. L. Grant

1995-01-01

80

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...

81

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....

82

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS  

SciTech Connect

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 the goal of developing a portable test kit for screening halogenated VOCs in the field.

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

2003-07-01

83

Volatile organic compounds from a Tuber melanosporum fermentation system.  

PubMed

A total of 59 volatile organic compounds (VOCs) were identified from Tuber melanosporum fermentation: 53 from its fermented mycelia and 32 from the fermentation broth. Alcohol-derived compounds were predominant in both the fermentation mycelia and the broth, although long chain fatty acids and isoprenoids were, for the first time, also found in the mycelia. The intense wine bouquet properties of the broth arose from several specific flavor substances, including sulfur compounds, pyrazines, furans and jasmones. Comparing the VOCs identified in this work with those previously reported, our results are more similar to the composition of the Tuber fruiting-body than previous Tuber fermentations. The composition and accumulation of flavor volatiles (e.g., pyrazines, sulfur compounds, and esters) and major constituents (e.g., 3-methyl-1-butanol and 2-phenylethanol) in this fermentation were significantly influenced by the sucrose concentration in the medium. The obtained information could therefore be useful in applications to convert the flavors of truffle mycelia similar to those of the fruiting-body by optimising the fermentation process. PMID:22980851

Li, Yuan-Yuan; Wang, Guan; Li, Hong-Mei; Zhong, Jian-Jiang; Tang, Ya-Jie

2012-07-14

84

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

PubMed

Plants synthesize an amazing diversity of volatile organic compounds (VOCs) that facilitate interactions with their environment, from attracting pollinators and seed dispersers to protecting themselves from pathogens, parasites and herbivores. Recent progress in -omics technologies resulted in the isolation of genes encoding enzymes responsible for the biosynthesis of many volatiles and contributed to our understanding of regulatory mechanisms involved in VOC formation. In this review, we largely focus on the biosynthesis and regulation of plant volatiles, the involvement of floral volatiles in plant reproduction as well as their contribution to plant biodiversity and applications in agriculture via crop-pollinator interactions. In addition, metabolic engineering approaches for both the improvement of plant defense and pollinator attraction are discussed in light of methodological constraints and ecological complications that limit the transition of crops with modified volatile profiles from research laboratories to real-world implementation. PMID:23383981

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

2013-02-06

85

PROJECTION METHODOLOGY FOR FUTURE STATE LEVEL VOLATILE ORGANIC COMPOUND EMISSIONS FROM STATIONARY SOURCES (VERSION 1.8)  

EPA Science Inventory

The report presents the model framework used to estimate state level and national future volatile organic compound (VOC) emissions and control costs for stationary industrial and utility sources. The framework involves a projection approach using the 1980 National Acid Precipitat...

86

Concentration stability of four volatile organic compounds in soil subsamples  

SciTech Connect

This study assesses the short-term (14- to 20-day) concentration stability of benzene, toluene, trans-1,2-dichloroethylene and trichloroethylene in soil matrices, in the absence of volatilization losses. Previously, holding time studies failed to eliminate volatilization as a variable, making them difficult to interpret. Here, vapor-fortified soil subsamples, sealed in glass ampoules for 16 days, experienced appreciable reductions in benzene, presumably attributable only to biodegradation. Treated soil subsamples, on the other hand, prepared without vapor losses for either aqueous extraction headspace or purge-and-trap analyses, showed appreciable reductions in toluene and lost all the benzene over a 14-day holding period at 4 deg C. These findings suggest that chemical preservatives are necessary to maintain volatile organic compound concentrations in soil when more than a couple of days pass between collection and analysis. Biodegradation, Soil samples, Holding time, Volatile-organic compounds.

Hewitt, A.D.

1994-04-01

87

Analysis of volatile organic compounds from illicit cocaine samples  

SciTech Connect

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.

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

1994-07-01

88

Volatile organic compounds from feces and their potential for diagnosis of gastrointestinal disease.  

PubMed

Little is known about the volatile organic compounds (VOCs) in feces and their potential health consequences. Patients and healthcare professionals have observed that feces often smell abnormal during gastrointestinal disease. The aim of this work was to define the volatiles emitted from the feces of healthy donors and patients with gastrointestinal disease. Our hypotheses were that i) VOCs would be shared in health; ii) VOCs would be constant in individuals; and iii) specific changes in VOCs would occur in disease. Volatile emissions in health were defined in a cohort and a longitudinal study. Subsequently, the pattern of volatiles found in the cohort study were compared to that found from patients with ulcerative colitis, Campylobacter jejuni, and Clostridium difficile. Volatiles from feces were collected by solid-phase microextraction and analyzed by gas chromatography/mass spectrometry. In the cohort study, 297 volatiles were identified. In all samples, ethanoic, butanoic, pentanoic acids, benzaldehyde, ethanal, carbon disulfide, dimethyldisulfide, acetone, 2-butanone, 2,3-butanedione, 6-methyl-5-hepten-2-one, indole, and 4-methylphenol were found. Forty-four compounds were shared by 80% of subjects. In the longitudinal study, 292 volatiles were identified, with some inter and intra subject variations in VOC concentrations with time. When compared to healthy donors, volatile patterns from feces of patients with ulcerative colitis, C. difficile, and C. jejuni were each significantly different. These findings could lead the way to the development of a rapid diagnostic device based on VOC detection. PMID:17314143

Garner, Catherine E; Smith, Stephen; de Lacy Costello, Ben; White, Paul; Spencer, Robert; Probert, Chris S J; Ratcliffe, Norman M

2007-02-21

89

Heterogeneous reactions of volatile organic compounds in the atmosphere  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

90

FIELD VALIDATION OF THE VOLATILE ORGANIC SAMPLING TRAIN (VOST) PROTOCOL  

EPA Science Inventory

With the development of the Volatile Organic Sampling Train (VOST) Protocol (February 1984) to measure organic emissions from hazardous waste incinerators, a wide variety of compounds have been collected and analyzed. Because its use is currently being recommended by regulatory a...

91

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

ERIC Educational Resources Information Center

|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.|

Chasteen, Thomas G.; Bentley, Ronald

2004-01-01

92

Bioconcentration factors for volatile organic compounds in vegetation.  

PubMed

Samples of air and leaves were taken at the University of Nevada [Formula: see text] Las Vegas campus and analyzed for volatile organic compounds using vacuum distillation coupled with gas chromatography/mass spectrometry. The data were used to estimate the bioconcentration of volatile organic compounds (VOCs) and to characterize the equilibration of VOCs between the leaves and air. The bioconcentration of volatiles in the leaves of some species can be predicted using the partition coefficients between air and octanol (K(oa)) and only considering VOC absorption in the lipid fraction of leaves. For these leaves, the bioconcentration factors agreed with existing models. Leaves of some species displayed a bioconcentration of volatiles that greatly exceeded theory. These hyperbioconcentration leaves also contain appreciable concentrations of monoterpenes, suggesting that a terpenoid compartment should be considered for the bioconcentration of organic compounds in leaves. Adding an additional "terpenoid" compartment should improve the characterization of volatile organic compounds in the environment. The uptake of VOCs from air by leaves is rapid, and the equilibration rates are seen to be quicker for compounds that have higher vapor pressures. The release of VOCs from the leaves of plants is slower for hyperbioconcentration leaves. PMID:21644617

Hiatt, M H

1998-03-01

93

Sorbent-based sampling methods for volatile and semi-volatile organic compounds in air  

Microsoft Academic Search

Sorbent tubes\\/traps are widely used in combination with gas chromatographic (GC) analytical methods to monitor the vapour-phase fraction of organic compounds in air. Target compounds range in volatility from acetylene and freons to phthalates and PCBs and include apolar, polar and reactive species. Airborne vapour concentrations will vary depending on the nature of the location, nearby pollution sources, weather conditions,

Elizabeth Woolfenden

2010-01-01

94

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

PubMed

To evaluate postmortem intervals (PMIs), one should take into account the determined age of necrophagous flies present on the cadaver. However, PMI determination needs further improvement, and rapid and accurate approaches have therefore to be developed. While previous studies have focussed on insect cuticular hydrocarbons, here we explore the volatile profile released by larvae and pupae of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). We monitored changes in volatile compounds daily, by headspace solid-phase microextraction, followed by gas chromatography-mass spectrometry. Branched and unbranched hydrocarbons, alcohols, esters and acids were identified, and the volatile profile was shown to vary, in both composition and quantity, with the age of the larva/pupa under investigation. We concluded, based on the analysis of the released volatile organic compounds, that it is possible to increase the accuracy of the estimated PMI, through improved estimation of the age of blowflies present on the cadaver. PMID:22341879

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

2012-02-16

95

Production of Volatile Fatty Acids by Some Lactic Acid Bacteria. II. Selective Formation of Volatile FattyAcids by Degradation of Amino Acids1  

Microsoft Academic Search

The kinds and amounts of volatile fatty acids (VFA) produced from single amino acids, modified amino acid mixtures, and pyruvate by resting cells of some streptococci and lactobacilli have been investigated. The effects of pit of substrate, temperature of incubation, and oxygen removal from substrate on VFA production from some selected amino acids were also studied. Two strains of lactic

T. Nakae; J. A. Elliott

1965-01-01

96

Transient oxidation of volatile organic compounds on aCuO\\/Al 2O 3 catalyst  

Microsoft Academic Search

Temperature-programmed desorption (TPD) and oxidation (TPO) were used to study decomposition and oxidation of methanol, ethanol, acetaldehyde, formic acid, and acetic acid on aCuO\\/Al2O3 catalyst. The volatile organic compounds (VOCs) were adsorbed on the alumina surface and diffused to the CuO to react. Lattice oxygen in CuO is active for deep oxidation, and as lattice oxygen is depleted, diffusion of

Eric M. Cordi; Peter J. O'Neill; John L. Falconer

1997-01-01

97

Oxidation of volatile organic compounds on a Ag\\/Al 2O 3 catalyst  

Microsoft Academic Search

Temperature-programmed desorption (TPD) and oxidation (TPO) were used to study decomposition and oxidation of methanol, ethanol, acetaldehyde, formic acid, and acetic acid on an Ag\\/Al2O3 catalyst. The volatile organic compounds (VOCs) were adsorbed on the alumina support. Silver was inactive for decomposition of adsorbed VOCs; all dehydration and dehydrogenation products evolved from reaction on the Al2O3 support during TPD. Silver

Eric M. Cordi; John L. Falconer

1997-01-01

98

21 CFR 573.914 - Salts of volatile fatty acids.  

Code of Federal Regulations, 2010 CFR

...FEED AND DRINKING WATER OF ANIMALS Food...Listing § 573.914 Salts of volatile fatty...percent. Ammonium salt of isobutyric acid 22 to 26 percent. Water 28 percent maximum...percent. Calcium salt of isobutyric acid...percent maximum. Water 14 percent...

2009-04-01

99

Relationship between acid volatile sulfide and the toxicity of zinc, lead and copper in marine sediments  

Microsoft Academic Search

It has been proposed that acid volatile sulfide (AVS) is an important sediment phase for determining the toxicity of certain trace metals. By evaluating the ratio of the molar quantities of simultaneously extracted metal (SEM) to AVS, the toxicity of metals to organisms in contact with sediment can be predicted. This study examines the role of AVS in prediction the

Atina M. Casas; Eric A. Crecelius

1994-01-01

100

Radiotracer Experiments on Biological Volatilization of Organic Iodine from Coastal Seawaters  

Microsoft Academic Search

Biological volatilization of iodine from seawaters was studied using a radiotracer technique. Seawater samples were incubated aerobically in serum bottles with radioactive iodide tracer (I), and volatile organic and inorganic iodine were collected with activated charcoal and silver wool trap, respectively. Iodine was volatilized mainly as organic iodine, and inorganic iodine volatilization was not observed. Influence of light intensity on

Seigo Amachi; Mizuyo Kasahara; Takaaki Fujii; Hirofumi Shinoyama; Satoshi Hanada; Yoichi Kamagata; Tadaaki Ban-nai; Yasuyuki Muramatsu

2004-01-01

101

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...

102

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...

103

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...

104

NATIONAL AMBIENT VOLATILE ORGANIC COMPOUNDS (VOCS) DATA BASE UPDATE, DOCUMENTATION  

EPA Science Inventory

Data on the observed concentrations of three hundred twenty (320) volatile organic compounds (VOCs) were compiled, critically evaluated, and assembled into a relational data base. Ambient (i.e., outdoor) measurements, indoor data, and data collected with personal monitors are inc...

105

Quantitative estimates of the volatility of ambient organic aerosol  

Microsoft Academic Search

Measurements of the sensitivity of organic aerosol (OA, and its components) mass to changes in temperature were recently reported by Huffman et al. (2009) using a tan- dem thermodenuder-aerosol mass spectrometer (TD-AMS) system in Mexico City and the Los Angeles area. Here, we use these measurements to derive quantitative estimates of aerosol volatility within the framework of absorptive parti- tioning

C. D. Cappa; J. L. Jimenez

2010-01-01

106

CHARACTERIZATION OF VOLATILE ORGANIC COMPOUNDS IN AIRBORNE DUST  

Technology Transfer Automated Retrieval System (TEKTRAN)

Three methods of extracting volatile organic compounds (VOC's) adsorbed on the airborne dust in a swine finishing building were investigated. Airborne dust was collected in pre-baked glass fiber filters (GFF's) and the compounds were extracted by solvent extraction using dichloromethane, solid phas...

107

REMOVAL OF VOLATILE ORGANIC CONTAMINANTS FROM GROUND WATER  

EPA Science Inventory

Because ground water is a source of potable water for millions of people, an economical means of removing volatile organic contaminants is essential. Laboratory, pilot-scale and full-scale studies are being carried out in the United States of America to determine the effect of va...

108

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...

109

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...

110

Volatile organic compounds in some urban locations in United States  

Microsoft Academic Search

Volatile organic compounds (VOCs) have been determined to be human risk factors in urban environments, as well as primary contributors to the formation of photochemical oxidants. Ambient air quality measurements of 54 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in or near 13 urban locations in the United States during September 1996 to August 1997. Air samples were

Mahmoud F. Mohamed; Daiwen Kang; Viney P. Aneja

2002-01-01

111

Assessment of volatile organic compound emissions from ecosystems of China  

Microsoft Academic Search

Isoprene, monoterpene, and other volatile organic compound (VOC) emissions from grasslands, shrublands, forests, and peatlands in China were characterized to estimate their regional magnitudes and to compare these emissions with those from landscapes of North America, Europe, and Africa. Ecological and VOC emission sampling was conducted at 52 sites centered in and around major research stations located in seven different

L. F. Klinger; Q.-J. Li; A. B. Guenther; J. P. Greenberg; B. Baker; J.-H. Bai

2002-01-01

112

Removal of Volatile Organic Compounds from polluted air  

Microsoft Academic Search

Volatile Organic Compounds (VOCs) are among the most common air pollutants emitted from chemical, petrochemical, and allied industries. VOCs are one of the main sources of photochemical reaction in the atmosphere leading to various environmental hazards; on the other hand, these VOCs have good commercial value. Growing environmental awareness has put up stringent regulations to control the VOCs emissions. In

Faisal I. Khan; Aloke Kr. Ghoshal

2000-01-01

113

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...

114

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...

115

Mass flow of a volatile organic liquid mixture in soils  

Microsoft Academic Search

The flow of kerosene, a volatile organic liquid mixture (VOLM), was studied in loam and clay soils and in a medium sand. The kerosene residual capacity and conductivity were determined for all three media at different initial moisture contents and with kerosene of different compositions. The kerosene conductivity of the soil was found to be strongly influenced by the soil

Z. Gerstl; Ts. Galin; B. Yaron

1994-01-01

116

REACTIVITY/VOLATILITY CLASSIFICATION OF SELECTED ORGANIC CHEMICALS: EXISTING DATA  

EPA Science Inventory

This study deals with the reactivity/volatility classification of some 118 organic chemicals specified by the U. S. Environmental Protection Agency (EPA). The classification system has been developed based on existing and available information. It was clear at the outset that lit...

117

FIELD EXPERIENCE WITH FOUR PORTABLE VOC (VOLATILE ORGANIC COMPOUND) MONITORS  

EPA Science Inventory

This report discusses the field operation problems associated with use of four portable volatile organic compound (VOC) detection instruments in conducting Reference Method 21 VOC screenings. The report presents the results of the field trials and summarizes the ease of use of ea...

118

Volatile organic compound emission factors from roadside measurements  

Microsoft Academic Search

Volatile organic compounds (VOCs) play a significant role in the generation of urban photochemical smog. In addition, some VOCs, such as benzene, are harmful to human health. In Japan, motor vehicles are the dominant source of VOCs. Therefore, it is important to determine the emission of VOCs from vehicles in order to estimate human risk and the production mechanisms of

Hiroto Kawashima; Shigeki Minami; Yoshimichi Hanai; Akihiro Fushimi

2006-01-01

119

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...

120

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...

121

Emission and Chemical Transformation of Biogenic Volatile Organic Compounds (echo)  

Microsoft Academic Search

Forests are complex sources of biogenic volatile organic compounds (VOC) in the planetary boundary layer. The impact of biogenic VOC on tropospheric photochem- istry, air quality, and the formation of secondary products affects our climate on a regional and global scale but is far from being understood. A considerable lack of knowledge exists concerning a forest stand as a net

R. Koppmann; T. Hoffmann; J. Kesselmeier; M. Schatzmann

2002-01-01

122

Reduction of volatile acidity of wines by selected yeast strains  

Microsoft Academic Search

Herein, we isolate and characterize wine yeasts with the ability to reduce volatile acidity of wines using a refermentation\\u000a process, which consists in mixing the acidic wine with freshly crushed grapes or musts or, alternatively, in the incubation\\u000a with the residual marc. From a set of 135 yeast isolates, four strains revealed the ability to use glucose and acetic acid

A. Vilela-Moura; D. Schuller; A. Mendes-Faia; M. Crte-Real

2008-01-01

123

Removal of volatile organic compounds from paper coatings  

NASA Astrophysics Data System (ADS)

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

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

1997-08-01

124

Mass transfer of volatile organics from large open basins  

SciTech Connect

Controlling the volatilization of organic compounds from treatment works is becoming increasingly important as the definition of industrial categorical standards for air emissions by the EPA draws nearer. In this light, specific volatilization rates of several volatile organic compounds (VOC`s) contained in multimillion gallon retention ({open_quotes}equalization basins{close_quotes}) and settling ({open_quotes}primary clarifier{close_quotes}) basins were measured using a flux chamber technique, a method used by the EPA for emission measurement. In this method, the liquid surface within an enclosing chamber is swept with air at a measured rate and the gas is analyzed. The mass transfer coefficients derived from these VOC vaporization rates were equal for the primary clarifier and the equalization basins. Factors were estimated to correct for the different ambient wind conditions to which these basins are exposed. Also it was determined that the rate of volatilization of VOC`s with low Henry`s law constants may be underestimated by the measurement. This is a result of the gas-phase resistance being dominant under the test conditions and the liquid-phase resistance being dominant under normal ambient conditions, and of the assumption that the liquid-phase resistance remains unchanged under both test and ambient conditions. The particular organics studied were acetone, methyl ethyl ketone, methyl isobutyl ketone, isopropanol, methanol and toluene. 7 refs., 4 figs., 9 tabs.

Sadek, S.E.; Gebel, R. [Ciba-Geigy Corporation, McIntosh, AL (United States); Smith, J.D. [Ciba-Geigy Corporation, Greensboro, NC (United States)] [and others

1996-12-31

125

Emissions and Secondary Organic Aerosol Production from Semivolatile and Intermediate Volatility Organic Compounds  

Microsoft Academic Search

Organic aerosols are a highly-dynamic system dominated by both variable gas-particle partitioning and chemical evolution. Important classes of organics include semivolatile and intermediate volatility organic compounds (SVOC and IVOC, respectively). SVOCs are compounds that exist in both the gas and particle phases at typical atmospheric conditions while IVOC are low-volatility vapors that exist exclusively in the gas phase. Both classes

A. L. Robinson; A. A. Presto; M. A. Miracolo; N. M. Donahue; J. H. Kroll; D. R. Worsnop

2008-01-01

126

Determination of volatile fatty acids in landfill leachates by ion-exclusion chromatography.  

PubMed

An ion-exclusion chromatographic method with on-line desalinization for the determination of volatile fatty acids in landfill leachates is described. Highly sensitive conductivity detection of the organic acids was achieved by using dilute p-hydroxybenzoic acid solution as an eluent. Interference with mineral acids was reduced by treatment with barium chloride solution prior to desalinization. A silver-loaded cation-exchange guard column for the desalinization was installed in series with the analytical column to avoid the contamination of organic acids. This method features detection limits of 0.01 mg L(-1) formic acid, 0.02 mg L(-1) acetic acid, 0.05 mg L(-1) propionic acid, and 0.1 mg L(-1) butyric acid, respectively, with an injection of 20 microL sample. Application of the on-line desalinization LC method is illustrated for leachate samples from a Japanese sanitary landfill. PMID:15334921

Yamamoto, Atsushi; Yasuhara, Akio; Kodama, Shuji; Matsunaga, Akinobu; Suzuki, Shigeru; Mohri, Shino; Yamada, Masato

2004-03-01

127

Reduction of volatile acidity of acidic wines by immobilized Saccharomyces cerevisiae cells.  

PubMed

Excessive volatile acidity in wines is a major problem and is still prevalent because available solutions are nevertheless unsatisfactory, namely, blending the filter-sterilized acidic wine with other wines of lower volatile acidity or using reverse osmosis. We have previously explored the use of an empirical biological deacidification procedure to lower the acetic acid content of wines. This winemaker's enological practice, which consists in refermentation associated with acetic acid consumption by yeasts, is performed by mixing the acidic wine with freshly crushed grapes, musts, or marc from a finished wine fermentation. We have shown that the commercial strain Saccharomyces cerevisiae S26 is able to decrease the volatile acidity of acidic wines with a volatile acidity higher than 1.44 g?L(-1) acetic acid, with no detrimental impact on wine aroma. In this study, we aimed to optimize the immobilization of S26 cells in alginate beads for the bioreduction of volatile acidity of acidic wines. We found that S26 cells immobilized in double-layer alginate-chitosan beads could reduce the volatile acidity of an acidic wine (1.1 g?L(-1) acetic acid, 12.5 % (v/v) ethanol, pH 3.12) by 28 and 62 % within 72 and 168 h, respectively, associated with a slight decrease in ethanol concentration (0.7 %). Similar volatile acidity removal efficiencies were obtained in medium with high glucose concentration (20 % w/v), indicating that this process may also be useful in the deacidification of grape musts. We, therefore, show that immobilized S. cerevisiae S26 cells in double-layer beads are an efficient alternative to improve the quality of wines with excessive volatile acidity. PMID:23361840

Vilela, A; Schuller, D; Mendes-Faia, A; Crte-Real, M

2013-01-30

128

Cost and Engineering Study - Control of Volatile Organic Emissions from Whiskey Warehousing.  

National Technical Information Service (NTIS)

This document provides cost and engineering information on control of volatile organic emissions from whiskey warehousing. Included are a description of whiskey aging, warehousing, and of volatile organic emissions from warehousing; a development of emiss...

D. C. Mascone

1978-01-01

129

LOCATING VOLATILE ORGANIC PLUMES ENTERING WATER BODIES USING PASSIVE VAPOR DIFFUSION SAMPLERS  

EPA Science Inventory

Many water bodies in New England are impacted by volatile organic contaminated groundwater intrusions. To determine the health and ecological impacts of these intrusions, it is important to locate fracture zones that transport groundwater contaminated with volatile organic compou...

130

Determination of Volatile Organic Content in Ultraviolet Radiation-Cured Coatings: Method Development.  

National Technical Information Service (NTIS)

Volatile organic compounds are important contributors to the formation of ozone in photochemical smog. To reduce the concentration of ozone in the environment, the Environmental Protection Agency (EPA) currently regulates volatile organic emissions from s...

E. E. Rickman R. K. M. Jayanty L. V. Jaffe

1993-01-01

131

75 FR 82363 - Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound Emission...  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Ohio; Volatile Organic Compound Emission Control Measures...and letterpress printing volatile organic compound (VOC) rule for approval into...with potential VOC ink oil emissions from the...

2010-12-30

132

77 FR 52630 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic...  

Federal Register 2010, 2011, 2012, 2013

...Quality Implementation Plans; Indiana; Volatile Organic Compounds; Architectural and Industrial Maintenance Coatings AGENCY...that sets emissions limits on the amount of volatile organic compounds in architectural and industrial maintenance coatings...

2012-08-30

133

Recovery of organic acids  

SciTech Connect

A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

Verser, Dan W. (Menlo Park, CA); Eggeman, Timothy J. (Lakewood, CO)

2011-11-01

134

Recovery of organic acids  

DOEpatents

A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

Verser, Dan W. (Golden, CO); Eggeman, Timothy J. (Lakewood, CO)

2009-10-13

135

Fungal wood decay in the presence of fly ash as indicated by gravimetrics and by extractability of low molecular weight volatile organic acids  

Microsoft Academic Search

A mycoremediation system of wood substrate and fungal inoculum was established on an organically poor fly ash deposit at the otanj Thermal Power Plant, Slovenia. A mini-block method with beech wood samples was used to select a suitable fungal isolate for inoculation into the mycoremediation system. Pleurotus ostreatus ZIM 76 proved to be the most appropriate for further tests. Compared

Barbara Pikur; Janja Zule; Mitja Pikur; Duan Jurc; Franc Pohleven

2009-01-01

136

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 2013-07-01 false Volatile Organic Compound (VOC), Content Limits for...PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for...

2013-07-01

137

40 CFR Table 1 to Subpart B of... - Volatile Organic Compound (VOC) Content Limits for Automobile Refinish Coatings  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Volatile Organic Compound (VOC) Content Limits for Automobile...PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for...

2013-07-01

138

40 CFR Table 1 to Subpart B of... - Volatile Organic Compound (VOC) Content Limits for Automobile Refinish Coatings  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Volatile Organic Compound (VOC) Content Limits for Automobile...CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Automobile...

2009-07-01

139

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

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Volatile Organic Compound (VOC), Content Limits for Architectural...CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for...

2009-07-01

140

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Volatile Organic Compound (VOC), Content Limits for Architectural...CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for...

2010-07-01

141

Screening of ground water samples for volatile organic compounds using a portable gas chromatograph  

Microsoft Academic Search

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

Buchmiller

2009-01-01

142

Emission of volatile organic compounds during composting of municipal solid wastes.  

PubMed

The objective of this study was to identify and quantify volatile and semi-volatile organic compounds (VOCs) produced during composting of the organic fraction of municipal solid wastes (MSW). A laboratory experiment was conducted using organic components of MSW that were decomposed under controlled aerobic conditions. Mixed paper primarily produced alkylated benzenes, alcohols and alkanes. Yard wastes primarily produced terpenes, alkylated benzenes, ketones and alkanes, while food wastes primarily produced sulfides, acids and alcohols. Among 13 aromatic VOCs found in MSW composting facilities, toluene, ethylbenzene, 1,4-dichlorobenzene, p-isopropyl toluene, and naphthalene were in the largest amounts. Unseeded mixed paper, seeded mixed paper, seeded yard wastes, unseeded yard wastes, seeded food wastes and unseeded food wastes produced approximately 6.5, 6.1, 2.1, 0.83, 2.5 and 0.33 mg of 13 volatile and semi-volatile aromatic organic compounds combined, respectively, per dry kg. All VOCs were emitted early during the composting process and their production rates decreased with time at thermophilic temperatures. PMID:15026225

Komilis, Dimitris P; Ham, Robert K; Park, Jae K

2004-04-01

143

Aromatic and volatile acid intermediates observed during anaerobic metabolism of lignin-derived oligomers  

SciTech Connect

Anaerobic enrichment cultures acclimated for 2 years to use a /sup 14/C-labeled, lignin-derived substrate with a molecular weight of 600 as a sole source of carbon were characterized by capillary and packed column gas chromatography. After acclimation, several of the active methanogenic organisms were inhibited with 2-bromoethanesulfonic acid, which suppressed methane formation and enhanced accumulation of a series of metabolic intermediates. Volatile fatty acids levels in 2-bromoethansulfonic acid-amended cultures were 10 times greater than those in the uninhibited, methane-forming organisms with acetate as the predominant component. Furthermore, in the 2-bromoethanesulfonic acid-amended organisms, almost half of the original substrate carbon was metabolized to 10 monaromatic compounds, with the most appreciable quantities accumulated as cinnamic, benzoic, caffeic, vanillic, and ferulic acids. 2-Bromoethanesulfonic acid seemed to effectively block CH/sub 4/ formation in the anaerobic food chain, resulting in the observed buildup of volatile fatty acids and monoaromatic intermediates. Neither fatty acids nor aromatic compounds were detected in the oligolignol substrate before its metabolism, suggesting that these anaerobic organisms have the ability to mediate the cleavage of the ..beta..-aryl-ether bond, the most common intermonomeric linkage in lignin, with the subsequent release of the observed constituent aromatic monomers.

Colberg, P.J.; Young, L.Y.

1985-02-01

144

Volatile organic compound emissions: an inventory for Western Europe  

SciTech Connect

The report gives details of an inventory compiled by CONCAWE and covering man-made non-methane volatile organic compound (VOC) emissions in Western Europe. The survey shows that the major man-made sources are road transport and solvents, each contributing around 40%. Total oil industry operations account for around 8%, with refining operations contribution about 2%. The major oil industry contribution comes from the distribution of gasoline, including vehicle refuelling (5%).

Edwards, A.H.; Campobasso, A.; Camps, R.; Cremer, G.; Long, M.D.

1986-01-01

145

Compositions of volatile organic compounds and methods of use thereof  

US Patent & Trademark Office Database

The present invention provides compositions and methods for treating, inhibiting or preventing the developing of a plant pathogenic disease. The compositions comprise volatile organic compounds effective to inhibit the growth of, or kill pathogenic microbes, including Ganoderma boninense. Invention compositions are especially useful in preventing and treating basal stem rot in the oil palm, and can be applied in the vicinity of the plant or used to sterilize the plant growth medium prior to or concurrent with plant growth therein.

2013-04-23

146

Determination of total volatile organic compound emissions from furniture polishes  

Microsoft Academic Search

In this study, an environmental test chamber with controlled temperature, relative humidity, and airflow rate was developed\\u000a to evaluate emissions of total volatile organic compounds (TVOCs) from three different kinds of furniture polish. The time\\u000a dependence of TVOC concentrations produced from the emissions of furniture polish products in the chamber was tested. TVOC\\u000a emissions from each furniture polish were compared.

Hai Guo; Frank Murray

2001-01-01

147

Structureactivity relationships of volatile organic chemicals as sensory irritants  

Microsoft Academic Search

We used a database of 145 volatile organic chemicals for which the sensory irritation potency (RD50) has been reported in mice. Chemicals were first separated into two groups: nonreactive and reactive, using Ferguson's rule.\\u000a This rule suggests that nonreactive chemicals induce their effect via a physical (?p) mechanism (i.e., weak forces or interactions between a chemical and a biological receptor).

Y. Alarie; M. Schaper; G. D. Nielsen; M. H. Abraham

1998-01-01

148

Hydrolysis rates of dissolved volatile organic compounds: Principles, temperature effects and literature review  

Microsoft Academic Search

Arrhenius parameters, 25 and 10 C rate constants for hydrolysis of most EPA 601\\/602 volatile organic compounds (VOCs), their hydrolytic progeny, and selected other VOCs are tabulated. Data include Arrhenius parameters for base-mediated hydrolysis of bromodichloromethane, bromoform, dibromochloromethane, and the acid-mediated hydrolysis of ethylene oxide which have not been published before. The average activation energy of the tabulated values, excepting

John W. Washington

1995-01-01

149

Volatile organic compound emissions from dry mill fuel ethanol production.  

PubMed

Ethanol fuel production is growing rapidly in the rural Midwest, and this growth presents potential environmental impacts. In 2002, the U.S. Environmental Protection Agency (EPA) and the Minnesota Pollution Control Agency (MPCA) entered into enforcement actions with 12 fuel ethanol plants in Minnesota. The enforcement actions uncovered underreported emissions and resulted in consent decrees that required pollution control equipment be installed. A key component of the consent decrees was a requirement to conduct emissions tests for volatile organic compounds (VOCs) with the goal of improving the characterization and control of emissions. The conventional VOC stack test method was thought to underquantify total VOC emissions from ethanol plants. A hybrid test method was also developed that involved quantification of individual VOC species. The resulting database of total and speciated VOC emissions from 10 fuel ethanol plants is relatively small, but it is the most extensive to date and has been used to develop and gauge compliance with permit limits and to estimate health risks in Minnesota. Emissions were highly variable among facilities and emissions units. In addition to the variability, the small number of samples and the presence of many values below detection limits complicate the analysis of the data. To account for these issues, a nested bootstrap procedure on the Kaplan-Meier method was used to calculate means and upper confidence limits. In general, the fermentation scrubbers and fluid bed coolers emitted the largest mass of VOC emissions. Across most facilities and emissions units ethanol was the pollutant emitted at the highest rate. Acetaldehyde, acetic acid, and ethyl acetate were also important emissions from some units. Emissions of total VOCs, ethanol, and some other species appeared to be a function of the beer feed rate, although the relationship was not reliable enough to develop a production rate-based emissions factor. PMID:17912928

Brady, Daniel; Pratt, Gregory C

2007-09-01

150

Solubility of volatile organic compounds in aqueous ammonia solution.  

PubMed

The Ostwald solubility coefficient, L of 17 volatile organic compounds (VOCs) from the gas phase into water and dilute aqueous ammonia solutions was determined by the equilibrium partitioning in closed system-solid phase micro extraction (EPICS-SPME) method at 303 K and at 0-2.5 mol dm(-3) ammonia concentrations. Ammonia increased the solubility of all VOCs nearly linearly, but to a different extent. The difference in the solubility values in aqueous ammonia solutions (Lmix) compared to pure water (L) is explained on the basis of a Linear Solvation Energy Relationship (LSER) equation made applicable for solvent mixtures, logLmix - logL = x((sNH3 - sH2O)pi2H + (aNH3 - aH2O)Sigma2H + (bNH3 - bH2O)Sigmabeta2H + (vNH3 - VH2O)Vx). sNH3 - sH2O, aNH3 - aH2O, bNH3 - bH2O, vNH3 - vH2O are the differences of solvent parameters, x is the mole fraction, pi2H is the solute dipolarity-polarizability, Sigmaalpha2H is the effective hydrogen bond acidity of the solute, Sigmabeta2H is the effective hydrogen bond basicity of the solute and Vx, the McGowan characteristic volume. The most significant term was v, the phase hydrophobicity. The solubility behavior was explained by the change in structure of the aqueous solution: the presence of ammonia reduces the cavity effect. These findings show that the presence of compounds such as ammonia, frequently observed in environmental waters, especially wastewaters, affect the fugacity of VOCs, having consequences for the environmental partitioning of VOCs and having technical consequences towards wastewater treatment technologies. PMID:15833481

Grgnyi, Mikls; Dewulf, Jo; Van Langenhove, Herman; Kirly, Zoltn

2005-05-01

151

Chemical mass balance for volatile organics in Chicago  

SciTech Connect

Increasing attention to the presence of atmospheric volatile organic compounds has focused interest on the sources and fate of organics in ambient air. The purpose of this study was to develop a chemical mass balance receptor model (CMB) to determine the contributions of major organic pollution source types to ambient pollution levels. Twenty mid-day ambient air samples were analyzed for the presence of volatile hydrocarbons by gas chromatographic procedures. Based on these measurements, contributions from vehicles, gasoline vapor emissions, and petroleum refineries to ambient organic concentrations were estimated. For the receptor site studied, vehicles were the dominant source type and accounted for 60.8 percent of the organics evaluated. Contributions from refineries, gasoline vapor, and all other sources were 10.1, 11.1, and 17.9 percent, respectively. Validation of the predictions showed that the model is sensitive to the effect of overall upwind emissions. The CMB model was shown to produce reasonable predictive results for vehicles, gasoline vapor, and refinery contributions to ambient non-methane organic concentrations.

O'Shea, W.J.; Scheff, P.A.

1988-08-01

152

Emission of volatile organic compounds to the atmosphere in the solvent sublation process. II. Volatile chlorinated organic compounds  

SciTech Connect

The mass of trichloroethylene, chlorobenzene, and 1,3-dichlorobenzene removed from an aqueous solution and emitted to the atmosphere during solvent sublation was determined experimentally. It was shown that the emission of these compounds in solvent sublation was reduced by 30 to 85% over air stripping under the same experimental conditions. The efficiency of removal of these compounds from water was also studied. The reduction of emissions over air stripping was more effective for the more hydrophobic and less volatile compounds. Emissions are reduced as the thickness of organic layer on the top of the column is increased. The use of decyl alcohol as the layer compound decreases emissions to a greater extent than does paraffin oil. Removal of these chlorinated volatile organic compounds from water by solvent sublation at an elevated temperature of 45{degrees}C is significantly faster than at room temperature. However, the emissions to the atmosphere are also increased.

Ososkov, V.; Kebbekus, B.; Chou, C.C. [New Jersey Inst. of Technology, Newark, NJ (United States)

1996-06-01

153

[Organ protective effects of volatile anesthetics and perioperative outcomes].  

PubMed

Anesthetic agents, especially, volatile anesthetics are considered to exert organ toxicity such as nephrotoxicity and hepatotoxicity; however, recent aggressive researches explored the beneficial effects of volatile anesthetics as an organ protectant. Ischemic preconditioning is a phenomenon in which single or multiple brief periods of ischemia have been shown to protect the myocardium and brain against prolonged ischemic insult. General anesthesia showed the protection against both ischemic myocardial and brain reperfusion injuries. This phenomenon is called anesthetic preconditioning. Regarding the organ protection, anesthetic preconditioning is one of the useful ways to diverse the organ protective effects not only to heart but also brain. Nowadays, ischemic postconditioning, consisting of repeated brief cycles of ischemia-reperfusion performed immediately after reperfusion following a prolonged ischemic insult, dramatically reduces infarct size in experimental models and such clinical studies are reported. Both preconditioning and postconditioning share the same signal transduction pathway and inhibit the mitochondrial permeability transition (MPT) that leads to either apoptosis or necrosis of myocardium and neuronal cell. Both phenomena look very promising, but we still lack the real evidence for human reserach in terms of the clinical outcome and further analysis is necessary. Neurotoxicities of anesthetic agents are very crucial problems for the patient and they are considered to be due to the activation of IP3 receptor in ER after exposure to volatile anesthetics. Massive release of Ca2+ from ER induces Ca2+ overload leading to mitochondria permeability transition (MPT) and induces apoptosis in the brain or aggravates the neurodegenerative disease. Susceptible mechanisms and beneficial treatment for the toxicity of general anesthesia is considered as a critical subject to discuss and challenge to solve for our future. PMID:22702090

Uchino, Hiroyuki; Suzuki, Morika; Okita, Ayano; Yuhnaiyama, Yohko; Shibuya, Mariko; Usui, Daiki; Miyashita, Ryoichi; Hatakeyama, Kiyoshi

2012-05-01

154

78 FR 11618 - Approval and Promulgation of Implementation Plans Tennessee: Revisions to Volatile Organic...  

Federal Register 2010, 2011, 2012, 2013

...Plans Tennessee: Revisions to Volatile Organic Compound Definition AGENCY: Environmental Protection Agency...Tennessee's September 3, 1999, SIP revision adds 17 compounds to the list of compounds excluded from the definition of ``Volatile...

2013-02-19

155

78 FR 22197 - Approval and Promulgation of Implementation Plans for Tennessee: Revisions to Volatile Organic...  

Federal Register 2010, 2011, 2012, 2013

...for Tennessee: Revisions to Volatile Organic Compound Definition AGENCY: Environmental Protection Agency...rule 1200-3-9-.01 to add a total of 17 compounds to the list of compounds excluded from the definition of ``Volatile...

2013-04-15

156

Monensin and Dichloroacetamide Influences on Methane and Volatile Fatty Acid Production by Rumen Bacteria In Vitro  

PubMed Central

The effect of monensin (0 or 33 ?g/g of diet) upon rumen fermentation in the presence and absence of methanogenesis was determined in vitro by using mixed rumen organisms continuously cultured for 17 days. Methane was inhibited by dichloroacetamide (DCA; 32 mg/day) or by a pH of 5.1. Monensin effected a significant decrease in the ratio of acetic to propionic acid in the presence or absence of methanogenesis. In the absence of methanogenesis, the decrease in the ratio of acetic to propionic acid was entirely the result of increased propionic acid, whereas in the presence of methanogenesis the decrease in the ratio was the result of a combination of decreased acetic acid and increased propionic acid. There was a complementary interaction between monensin and DCA on volatile fatty acid production (expressed as millimoles of carbon per day). Addition of monensin to DCA-treated cultures resulted in the production of more acid; however, monensin and DCA had no beneficial effect on total carbon formed as acid and gases as compared with nonsupplemented control cultures. The monensin and DCA also resulted in greater digestion of neutral detergent fiber and less accumulation of formic acid and hydrogen as end products than did DCA alone. l-Lactic acid was produced in small but significantly greater amounts by the low-pH cultures, which also had less volatile fatty acid carbon formed from the fiber fraction of the forage supplied.

Slyter, L. L.

1979-01-01

157

Seasonal variation of acid volatile sulfide concentration in sediment cores from three northeastern Minnesota lakes  

Microsoft Academic Search

Acid volatile sulfide (AVS) is a natural agent in sediments which complexes some cationic metals and thereby influences the\\u000a toxicity of these metals to benthic organisms. Because of its influence on metal bioavailability, AVS has been proposed as\\u000a a key normalization phase for the development of sediment quality criteria for metals. However, studies conducted primarily\\u000a in marine and estuarine systems

E. N. Leonard; V. R. Mattson; D. A. Benoit; R. A. Hoke; G. T. Ankley

1993-01-01

158

Preliminary evaluation of selected in situ remediation technologies for Volatile Organic Compound contamination at Arid sites  

SciTech Connect

To support the Volatile Organic Compounds-Arid Site (VOC-Arid) Integrated Demonstration (ID) in its technical, logistical, institutional, and economical testing of emerging environmental management and restoration technologies. Pacific Northwest Laboratory(a) is evaluating several in situ remediation technologies for possible inclusion in the demonstration. The evaluations are made with respect to the initial focus of the VOC-Arid ID: the carbon tetrachloride contamination at the Hanford Site, where it was disposed to the vadose zone along with other volatile and nonvolatile organic wastes. heavy metals, acids. and radionuclides. The purposes of this report are (1) to identify candidate in situ technologies for inclusion in the program, (2) to evaluate the candidate technologies based on their potential applicability to VOC contamination at arid sites and geologic conditions representative of the ID host site (i.e., Hanford Site), and (3) to prioritize those technologies for future US Department of Energy (DOE) support.

Lenhard, R.J.; Gerber, M.A.; Amonette, J.E.

1992-10-01

159

Volatile organic compound losses from sewage sludge-amended soils  

SciTech Connect

Volatile organic compounds (VOCs) applied to soil in sludge have been assumed to disappear quickly and completely. The VOC behavior in sludge-amended soils has been studied previously only in laboratory systems where the sludged soil has been spiked with compounds of interest. Behavior in these systems may not necessarily represent compound behavior in field soils to which contaminated sludge is added. A series of laboratory microcosm experiments were designed therefore to investigate the behavior of toluene, ethyl benzene, o-, m-, and p-xylene applied to soil in contaminated sludge, and factors influencing loss processes. The VOC loss from sludge-amended soil was well described by a simple one step pseudo-first-order model but in certain soils was better described by a two step first-order model. Volatilization was the predominant loss process. Rates of loss depended on sludge application rate, method of sludge application, soil properties, and on compound characteristics. Experiments indicated that spiking sludge-amended soils gave a reasonable indication of VOC loss rates from systems amended with contaminated sludge at least over a period of 23 d. The majority of VOCs applied to soils in sludge volatilizes quickly to the atmosphere over a few to 10s of days with a small fraction lost more slowly. Potential for VOC crop uptake, livestock ingestion, and contamination of ground water is low under routine, managed applications of sewage sludge to agricultural land.

Wilson, S.C.; Jones, K.C.

1999-08-01

160

Analysis of organic volatile flavor compounds in fermented stinky tofu using SPME with different fiber coatings.  

PubMed

The organic volatile flavor compounds in fermented stinky tofu (FST) were studied using SPME-GC/MS. A total of 39 volatile compounds were identified, including nine esters, seven alcohols, five alkenes, four sulfides, three heterocycles, three carboxylic acids, three ketones, two aldehydes, one phenol, one amine and one ether. These compounds were determined by MS, and conformed by comparison of the retention times of the separated constituents with those of authentic samples and by comparison of retention indexes (RIs) of separated constituents with the RIs reported in the literature. The predominant volatile compound in FST was indole, followed by dimethyl trisulfide, phenol, dimethyl disulfide and dimethyl tetrasulfide. In order to find a better extraction time, the extraction times was optimized for each type of SPME fiber; the results show that the best extraction time for Carboxen/PDMS is 60 min, for PDMS/DVB 30 min, for DVB/CAR/PDMS 60 min and for PDMS 75 min. Of the four fibers used in this work, Carboxen/PDMS is found to be the most suitable to extract the organic volatile flavor compounds in fermented stinky tofu. PMID:22450681

Liu, Yuping; Miao, Zhiwei; Guan, Wei; Sun, Baoguo

2012-03-26

161

Stability of volatile organics in environmental soil samples. Final report  

SciTech Connect

This report focuses on data generated for the purpose of establishing the stability of 19 volatile organic compounds in environmental soil samples. The study was carried out over a 56 day (for two soils) and a 111 day (for one reference soil) time frame and took into account as many variables as possible within the constraints of budget and time. The objectives of the study were: 1) to provide a data base which could be used to provide guidance on pre-analytical holding times for regulatory purposes; and 2) to provide a basis for the evaluation of data which is generated outside of the currently allowable holding times.

Maskarinec, M.P.; Bayne, C.K.; Jenkins, R.A.; Johnson, L.H.; Holladay, S.K.

1992-11-01

162

Stability of volatile organics in environmental soil samples  

SciTech Connect

This report focuses on data generated for the purpose of establishing the stability of 19 volatile organic compounds in environmental soil samples. The study was carried out over a 56 day (for two soils) and a 111 day (for one reference soil) time frame and took into account as many variables as possible within the constraints of budget and time. The objectives of the study were: 1) to provide a data base which could be used to provide guidance on pre-analytical holding times for regulatory purposes; and 2) to provide a basis for the evaluation of data which is generated outside of the currently allowable holding times.

Maskarinec, M.P.; Bayne, C.K.; Jenkins, R.A.; Johnson, L.H.; Holladay, S.K.

1992-11-01

163

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

PubMed

In this study 29 PVC floor coverings were tested for emission of vinyl chloride (VC) and other volatile organic compounds (VOCs). A study on the effect of higher temperature on emission of VOCs from newly manufactured PVC flooring was also carried out. The study was conducted in climatic chamber, according to Polish Standard PN-89/Z-04021. GC method was used for analyzing of the compounds emitted. VC was not emitted from any of the floorings tested. Other VOCs were emitted in different concentrations. The influence of temperature on emission was conducted at temperatures of 23 degrees C and 35 degrees C from 2 hrs up to 180 days after introduction of materials in the chamber. The increase of temperature caused increase of total volatile organic compounds (TVOC) emission during 24 hrs of experiment. Then the emission was comparable for both temperatures. After 9 days emission of identified and unidentified compounds (TVOC) showed a rapid decay and stayed on very low level during a few months. The study conducted showed that PVC floorings after 10 days of installation in the room should not be source of indoor air contamination. PMID:10431652

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

1998-01-01

164

Emerging site characterization technologies for volatile organic compounds  

SciTech Connect

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

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

1992-05-01

165

Emerging site characterization technologies for volatile organic compounds  

SciTech Connect

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

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

1992-05-01

166

Volatile organic compounds in Gulf of Mexico sediments  

SciTech Connect

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.

McDonald, T.J.

1988-01-01

167

On-line monitoring of volatile organic species  

SciTech Connect

On-line chemical monitoring systems can help ensure safe, environmentally sound operation of industrial processes using hazardous chemicals. Using polymer-coated surface acoustic wave (SAW) sensors, we have demonstrated monitors that are capable of detecting dilute concentrations of volatile organic species. Using changes in both wave velocity and wave attenuation, the identity and concentration of an isolated chemical species can be determined. A polysiloxane coating has been found to provide unique properties for monitoring chlorinated hydrocarbons (CHCs) such as trichloroethylene: good discrimination of CHCs from most other organic species, rapid and reversible sensor response, and low detection limits. Using this technology, a portable acoustic wave sensor (PAWS) system has been constructed. 7 refs., 4 figs.

Frye, G.C.; Martin, S.J.

1990-01-01

168

Identification and use of potential bacterial organic antifungal volatiles in biocontrol  

Microsoft Academic Search

Bacteria, isolated from canola and soybean plants, produced antifungal organic volatile compounds. These compounds inhibited sclerotia and ascospore germination, and mycelial growth of Sclerotinia sclerotiorum, in vitro and in soil tests. Ascospore germination in cavity slides was inhibited 5490% by the volatile producers. When mycelial plugs or the sclerotia, exposed to these volatiles, were transferred to fresh agar plates, the

W. G. Dilantha Fernando; Rajesh Ramarathnam; Akkanas S. Krishnamoorthy; Sarah C. Savchuk

2005-01-01

169

Volatility of secondary organic aerosols from the ozone initiated oxidation of ? -pinene and limonene  

Microsoft Academic Search

The volatility of secondary organic aerosol (SOA) from the ozone initiated oxidation of ?-pinene and limonene has been investigated in a large aerosol chamber facility, the AIDA chamber of Research Centre Karlsruhe, by using a volatility tandem-DMA system (VTDMA). The volatility of particles has been classified by monitoring the change in particle peak diameter at temperatures between 298 and 583K.

sa M. Jonsson; Mattias Hallquist; Harald Saathoff

2007-01-01

170

Screening of ground water samples for volatile organic compounds using a portable gas chromatograph  

USGS Publications Warehouse

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

Buchmiller, R. C.

1989-01-01

171

Program to Establish In situ Immobilization as a Remedial Action Option for Wastes Containing Volatile Organic Compounds (VOC).  

National Technical Information Service (NTIS)

Sludges and soils containing volatile organic compounds (VOC), base-neutralized acids (BNA), and heavy metals are a generic problem on many military bases due to petroleum fuel-handling activities, metal stripping, fire training, and/or other processing a...

M. I. Morris R. D. Spence T. M. Gilliam L. R. Dole

1988-01-01

172

Emission of volatile organic compounds during composting of municipal solid wastes  

Microsoft Academic Search

The objective of this study was to identify and quantify volatile and semi-volatile organic compounds (VOCs) produced during composting of the organic fraction of municipal solid wastes (MSW). A laboratory experiment was conducted using organic components of MSW that were decomposed under controlled aerobic conditions. Mixed paper primarily produced alkylated benzenes, alcohols and alkanes. Yard wastes primarily produced terpenes, alkylated

Dimitris P Komilis; Robert K Ham; Jae K Park

2004-01-01

173

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline...Terminals § 60.502 Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline...collection system designed to collect the total organic compounds vapors displaced from tank...

2013-07-01

174

40 CFR Table 2 to Subpart II of... - Volatile Organic HAP (VOHAP) Limits for Marine Coatings  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Volatile Organic HAP (VOHAP) Limits for Marine Coatings...2 to Subpart II of Part 63Volatile Organic HAP (VOHAP) Limits for Marine Coatings... 728 Nuclear 420 841 1,069 Organic zinc 360 630 802...

2013-07-01

175

77 FR 38761 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic...  

Federal Register 2010, 2011, 2012, 2013

...Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compounds; Consumer Products AGENCY: Environmental Protection...and other restrictions on consumer products that are sold, supplied,...

2012-06-29

176

Electrophysiological and behavioral responses of Thanatophilus sinuatus Fabricius (Coleoptera: Silphidae) to selected cadaveric volatile organic compounds.  

PubMed

Soon after death, carcasses release volatile chemicals that attract carrion insects including Silphidae. Nevertheless, it is not known which chemical cues are involved in the attractiveness of the carcass. So far, little information is available on the chemical ecology of carrion beetles, particularly concerning the subfamily of Silphinae. The biological role of selected cadaveric volatile organic compounds including dimethyldisulfide (DMDS), butan-1-ol, n-butanoic acid, indole, phenol, p-cresol, putrescine, and cadaverine on the silphine species, Thanatophilus sinuatus Fabricius, was investigated using both electrophysiological and behavioral techniques. Among the tested cadaveric compounds, butan-1-ol and DMDS elicited the strongest electroantennography (EAG) from both T. sinuatus male and female antennae. In a two-arm olfactometer, males and females were significantly attracted to DMDS for both tested doses, whereas only males were attracted to p-cresol at 100 ng. Putrescine was repellent to males at the dose of 1 ?g. PMID:23822801

Dekeirsschieter, Jessica; Frederickx, Christine; Lognay, Georges; Brostaux, Yves; Verheggen, Francois J; Haubruge, Eric

2013-07-03

177

Inhibition of reticulo-ruminal motility by volatile fatty acids and lactic acid in sheep.  

PubMed Central

1. A study was made of the influence on reticulo-ruminal motility, recorded by electromyography, of ruminal infusions of volatile fatty acids (VFAs) and lactic acid in twenty-four sheep maintained by intragastric infusion of a complete liquid diet, in three sheep fed grass pellets, and in nine chronically vagotomized sheep; abomasal and duodenal infusions of VFA and lactic acid were tested in five sheep fed grass pellets. 2. Ruminal infusions of VFAs and lactic acid progressively inhibited the amplitude of the reticulo-ruminal contractions. In many experiments there was no effect on contraction frequency until the cessation of all reticulo-ruminal contractions at which point the maximal concentration of VFA recorded in the abomasum was 28 mM, and that of lactic acid was 20 mM. 3. The concentrations of undissociated VFAs causing cessation of reticulo-ruminal contractions in the vagus-intact sheep were very similar to the concentrations causing abolition of the organized intrinsic motility of the chronically vagotomized sheep. 4. The inhibition of reticulo-ruminal motility with ruminal infusions of mixtures of VFAs and of lactic acid together with VFAs could largely be explained by the sum of the effects of the individual acids present. 5. Abomasal infusion of VFA or lactic acid inhibited the amplitude of ruminal, especially primary ruminal, contractions at concentrations of undissociated acid of 60 mM and above and increased the frequency of reticulum and primary ruminal contractions at about 80 mM. 6. Duodenal infusion of VFAs and lactic acid (100 mM, 5 ml/min) strongly inhibited abomasal motility without affecting reticulo-ruminal motility, and at a higher rate (100 mM, 10 ml/min) abolished motility and inhibited both the amplitude and frequency of reticulo-ruminal contractions. 7. It is concluded that the initial inhibition of reticulo-ruminal motility in ruminal acidosis is unlikely to involve any significant influence from duodenal, or abomasal receptors. The final cessation of reticulo-ruminal motility with ruminal acidosis could involve local effects of VFAs in the reticulo-rumen as well as through excitation of acid-sensitive reticulo-ruminal receptors.

Gregory, P C

1987-01-01

178

Using volatile fatty acid relationships to predict anaerobic digester failure  

SciTech Connect

During recent years, a number of observations have been made in the literature regarding the level and ratio of certain organic acids and the correlation of these acid relationships with anaerobic digester performance, either complete failure or operation in a stressed state. It is an accepted fact that levels of organic acid are important in digestion for two reasons: (a) organic acids (particularly acetic) are the immediate precursors in the metabolic chain leading to methane formation and (b) if present in high concentration, acids are known to cause stress in the microbial population and can ultimately lead to complete process failure. The recent literature (approximately the last 7 years) was searched for digester performance data and organic acid levels. Seventy observations were used in arriving at a relationship between acetic acid level and propionic to acetic acid ratio and digester failure or success. Methane productivity (L CH4/g VS added) was used as the parameter determining digester performance. A definite trend was recognized that suggests acetic acid levels in excess of 800 mg/L or a propionic to acetic acid ratio greater than 1.4 indicate impending digester failure. A laboratory scale study was then conductd to verify this phenomenon. (Refs. 22).

Hill, D.T.; Cobb, S.A.; Bolte, J.P.

1987-01-01

179

Organic volatile sulfur compounds in inland aquatic systems  

SciTech Connect

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

Richards, S.R.

1991-01-01

180

Residential pollutants and ventilation strategies: Volatile organic compounds and radon  

SciTech Connect

This paper reviews literature that reports investigations of residential ventilation and indoor air quality. Two important residential pollutant classes, volatile organic compounds and radon, are examined. A companion paper examines moisture and combustion pollutants. Control strategies recommended from the review include appropriate building design to prevent or limit the sources of the pollutants within the space, proper operation and maintenance to prevent adverse conditions from developing during the building's life and appropriate use of ventilation. The characteristics of these pollutant sources suggest that ventilation systems in residences should have several properties. They should have the extra capacity available to reduce short bursts of pollution, be located close to the expected source of the contamination, and be inexpensive. Mitigation of radon is technically a major success using a form of task ventilation. Whole-house ventilation is, at best, a secondary form of control of excess radon in residences.

Grimsrud, D.T.; Hadlich, D.E.

1999-07-01

181

Nanoenabled microelectromechanical sensor for volatile organic chemical detection  

NASA Astrophysics Data System (ADS)

A nanoenabled gravimetric chemical sensor prototype based on the large scale integration of single-stranded DNA (ss-DNA) decorated single-walled carbon nanotubes (SWNTs) as nanofunctionalization layer for aluminum nitride contour-mode resonant microelectromechanical (MEM) gravimetric sensors has been demonstrated. The capability of two distinct single strands of DNA bound to SWNTs to enhance differently the adsorption of volatile organic compounds such as dinitroluene (simulant for explosive vapor) and dymethyl-methylphosphonate (simulant for nerve agent sarin) has been verified experimentally. Different levels of sensitivity (17.3 and 28 KHz ?m2/fg) due to separate frequencies of operation (287 and 450 MHz) on the same die have also been shown to prove the large dynamic range of sensitivity attainable with the sensor. The adsorption process in the ss-DNA decorated SWNTs does not occur in the bulk of the material, but solely involves the surface, which permits to achieve 50% recovery in less than 29 s.

Zuniga, Chiara; Rinaldi, Matteo; Khamis, Samuel M.; Johnson, A. T.; Piazza, Gianluca

2009-06-01

182

Flux Measurements of Volatile Organic Compounds from an Urban Landscape  

SciTech Connect

Direct measurements of volatile organic compound (VOC) emissions that include all anthropogenic and biogenic emission sources in urban areas are a missing requirement to evaluate emission inventories and constrain current photochemical modelling practices. Here we demonstrate the use of micrometeorological techniques coupled with fast-response sensors to measure urban VOC fluxes from a neighborhood of Mexico City, where the spatial variability of surface cover and roughness is high. Fluxes of olefins, methanol, acetone, toluene and C2-benzenes were measured and compared with the local gridded emission inventory. VOC fluxes exhibited a clear diurnal pattern with a strong relationship to vehicular traffic. Recent photochemical modeling results suggest that VOC emissions are significantly underestimated in Mexico City1, but the measured VOC fluxes described here indicate that the official emission inventory2 is essentially correct. Thus, other explanations are needed to explain the photochemical modelling results.

Velasco, E.; Lamb, Brian K.; Pressley, S.; Allwine, Eugene J.; Westberg, Halvor; Jobson, B Tom T.; Alexander, M. Lizabeth; Prazeller, Peter; Molina, Luisa; Molina, Mario J.

2005-10-19

183

Catalytic oxidation process cleans volatile organics from exhaust  

SciTech Connect

Unsteady-state catalytic oxidation is the basis of a technology now becoming available in the US for removing volatile organic compounds (VOCs) from industrial exhaust streams. The technology originated in Russia and is being developed for the US market by Monsanto Enviro-Chem Systems, St. Louis. At least 149 of the 189 pollutants identified by EPA are VOCs. EPA estimates that the initial cost to industry for equipment to remove the hazardous materials will be about $350 million. The expected annual maintenance bill to treat the major pollution sources is about $182 million. Catalytic oxidizers are applicable to most, but not all, VOC removal applications. The advantages in most cases are VOC removal efficiencies of at least 99%, half the energy requirement of other systems, low operating temperatures, stable operation with variable flow rates and VOC concentrations, and low capital and operating costs.

Haggin, J.

1994-06-27

184

Detection of volatile organic compounds using surface enhanced Raman scattering  

SciTech Connect

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.

Chang, A S; Maiti, A; Ileri, N; Bora, M; Larson, C C; Britten, J A; Bond, T C

2012-03-22

185

A novel nanostructure for ultrasensitive volatile organic compound sensing  

NASA Astrophysics Data System (ADS)

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.

Zhao, Huaizhou; Rizal, Binod; Ren, Zhifeng; Naughton, Michael J.; Chiles, Thomas C.; Cai, Dong

2011-03-01

186

Source apportionment of volatile organic compounds in Tehran, Iran.  

PubMed

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

Sarkhosh, Maryam; Mahvi, Amir Hossein; Yunesian, Masud; Nabizadeh, Ramin; Borji, Saeedeh Hemmati; Bajgirani, Ali Ghiami

2013-01-03

187

Source characteristics of oxygenated volatile organic compounds and hydrogen cyanide  

NASA Astrophysics Data System (ADS)

Airborne trace gas measurements from Transport and Chemical Evolution over the Pacific (TRACE-P), Pacific Exploratory Mission (PEM)-Tropics B, and Intercontinental Chemical Transport Experiment-North America (INTEX-NA) experiments are analyzed to examine the major source factors contributing to the observed variabilities of oxygenated volatile organic compounds and cyanides. The positive matrix factorization method is applied to coincident measurements of 11 chemicals including CH3OH, CH3COCH3, CH3CHO, C2H2, C2H6, i-C5H12, CO, CH3Cl, and CHBr3. Measurements of HCN and CH3CN are available for TRACE-P and INTEX-NA. We identify major source contributions from the terrestrial biosphere, biomass burning, industry/urban regions, and oceans. Spatial and back trajectory characteristics of these factors are examined. On the basis of TRACE-P and PEM-Tropics B data, we find a factor that explains 80-88% of the CH3OH variability, 20-40% of CH3COCH3, 7-35% of CH3CHO, and 41% of HCN, most likely representing the emissions from terrestrial biosphere. Our analysis suggested that biogenic emissions of HCN may be significant. Cyanogenesis in plants is likely a major emission process for HCN, which was not fully accounted for previously. Larger contributions than previous global estimations to CH3COCH3 and CH3CHO by biomass burning and industry/urban sources likely reflect significant secondary production from volatile organic compound oxidation. No evidence was found for large emissions of CH3COCH3 from the ocean. The oceanic CH3CHO contribution implies large regional variations.

Shim, Changsub; Wang, Yuhang; Singh, Hanwant B.; Blake, Donald R.; Guenther, Alex B.

2007-05-01

188

Source characteristics of oxygenated volatile organic compounds and hydrogen cyanide  

NASA Astrophysics Data System (ADS)

Airborne trace gas measurements from TRACE-P, PEM-Tropics B, and INTEX-NA experiments are analyzed to examine the major source factors contributing to the observed variabilities of oxygenated volatile organic compounds and cyanides. Positive matrix factorization (PMF) is applied to coincident measurements of 11 chemicals including CH3OH, CH3COCH3, CH3CHO, C2H2, C2H6, i-C5H12, CO, CH3Cl, and CHBr3. Measurements of HCN and CH3CN are available for TRACE-P and INTEX-NA. We identify major source contributions from the terrestrial biosphere, biomass burning, industry/urban regions, and oceans. Spatial and backtrajectory characteristics of these factors are examined. Based on TRACE-P and PEM-Tropics B data, we find that the terrestrial biogenic factor explains 80-88% of the CH3OH variability, 20-40% of CH3COCH3, 7-35% of CH3CHO, and 41% of HCN. The biogenic contribution to HCN derived from this analysis is much larger than previous global estimates. Cyanogenesis in plants is likely a major emission process for HCN, not fully accounted for previously. Larger contributions than previous global estimations to CH3COCH3 and CH3CHO by biomass burning and industry/urban sources likely reflect significant secondary production from volatile organic compounds (VOC) oxidation. No evidence was found for large emissions of CH3COCH3 from the ocean. The oceanic CH3CHO contribution implies large regional variations.

Wang, Y.; Shim, C.; Singh, H.; Blake, D.; Guenther, A.

2006-12-01

189

CCN activity and volatility of ?-caryophyllene secondary organic aerosol  

NASA Astrophysics Data System (ADS)

In a series of smog chamber experiments, the Cloud Condensation Nuclei (CCN) activity of Secondary Organic Aerosol (SOA) generated from ozonolysis of ?-caryophyllene was characterized by determining the CCN derived hygroscopicity parameter, ?CCN, from experimental data. Two types of CCN counters, operating at different temperatures, were used. The effect of semi-volatile organic compounds on the CCN activity of SOA was studied using a thermodenuder. Overall, SOA was only slightly CCN active (with ?CCN in the range 0.001-0.16), and in dark experiments with no OH scavenger present, ?CCN decreased when particles were sent through the thermodenuder (with a temperature up to 50 C). SOA was generated under different experimental conditions: in some experiments, an OH scavenger (2-butanol) was added. SOA from these experiments was less CCN active than SOA produced in experiments without an OH scavenger (i.e. where OH was produced during ozonolysis). In other experiments, lights were turned on, either without or with the addition of HONO (OH source). This led to the formation of more CCN active SOA. SOA was aged up to 30 h through exposure to ozone and (in experiments with no OH scavenger present) to OH. In all experiments, the derived ?CCN consistently increased with time after initial injection of ?-caryophyllene, showing that chemical ageing increases the CCN activity of ?-caryophyllene SOA. ?CCN was also observed to depend on supersaturation, which was explained either as an evaporation artifact from semi-volatile SOA (only observed in experiments lacking light exposure) or, alternatively, by effects related to chemical composition depending on dry particle size. Using the method of Threshold Droplet Growth Analysis it was also concluded that the activation kinetics of the SOA do not differ significantly from calibration ammonium sulphate aerosol.

Frosch, M.; Bilde, M.; Nenes, A.; Praplan, A. P.; Jurnyi, Z.; Dommen, J.; Gysel, M.; Weingartner, E.; Baltensperger, U.

2012-08-01

190

Adsorption of volatile organic compounds in porous metalorganic frameworks functionalized by polyoxometalates  

Microsoft Academic Search

The functionalization of porous metalorganic frameworks (Cu3(BTC)2) was achieved by incorporating Keggin-type polyoxometalates (POMs), and further optimized via alkali metal ion-exchange. In addition to thermal gravimetric analysis, IR, single-crystal X-ray diffraction, and powder X-ray diffraction, the adsorption properties were characterized by N2 and volatile organic compounds (VOCs) adsorption measurements, including short-chain alcohols (C<4), cyclohexane, benzene, and toluene. The adsorption enthalpies

Feng-Ji Ma; Shu-Xia Liu; Da-Dong Liang; Guo-Jian Ren; Feng Wei; Ya-Guang Chen; Zhong-Min Su

2011-01-01

191

Effects of additional nonmethane volatile organic compounds, organic nitrates, and direct emissions of oxygenated organic species on global tropospheric chemistry  

NASA Astrophysics Data System (ADS)

This work evaluates the sensitivity of tropospheric ozone and its precursors to the representation of nonmethane volatile organic compounds (NMVOCs) and organic nitrates. A global 3-D tropospheric chemistry/transport model (IMPACT) has been exercised initially using the GEOS-Chem chemical reaction mechanism. The model was then extended by adding emissions and photochemical reactions for aromatic and terpenoid hydrocarbons, and by adding explicit representation of hydroxy alkyl nitrates produced from isoprene. Emissions of methanol, phenol, acetic acid and formic acid associated with biomass burning were also added. Results show that O3 increases by 20% in most of the troposphere, peroxyacetyl nitrate (PAN) increases by 30% over much of the troposphere and OH increases by 10%. NOx (NO + NO2) decreases near source regions and increases in remote locations, reflecting increased transport of NOx away from source regions by organic nitrates. The increase in O3 was driven largely by the increased role of PAN as a transporter of NOx and by the rerelease of NOx from isoprene nitrates. The increased PAN production was associated with increases in methyl glyoxal and hydroxyacetone. Comparison with measured values show reasonable agreement for O3 and PAN, but model measurement agreement does not either improve or degrade in the extended model. The extended model shows improved agreement with measurements for methanol, acetic acid and peroxypropional nitrate (PPN). Results from the extended model were consistent with measured alkyl nitrates and glycolaldehyde, but hydroxyacetone and methyl glyoxal were overestimated. The latter suggests that the effect of the isoprene nitrates is somewhat smaller than estimated here. Although the model measurement comparison does not show specific improvements with the extended model, it provides a more complete description of tropospheric chemistry that we believe is important to include.

Ito, Akinori; Sillman, Sanford; Penner, Joyce E.

2007-03-01

192

Oxidation of volatile organic compounds on AlO, Pd\\/AlO, and PdO\\/AlO catalysts  

Microsoft Academic Search

Temperature-programmed desorption (TPD) and oxidation (TPO) were used to study the decomposition and oxidation of methanol, ethanol, acetaldehyde, formic acid, and acetic acid on AlO, Pd\\/AlO, and PdO\\/AlO catalysts. The oxidation and decomposition rates were much higher on Pd\\/AlO than on AlO, even though the volatile organic compounds (VOCs) were adsorbed on the AlO support in both cases. The VOCs

E. Cordi; J. L. Falconer

1996-01-01

193

Effects of airborne volatile organic compounds on plants.  

PubMed

Routine measurements of volatile organic compounds (VOCs) in air have shown that average concentrations are very much smaller than those used in laboratory experiments designed to study the effects of VOCs on plants. However, maximum hourly concentrations of some VOCs can be 100 times larger than the average, even in rural air. Experimental studies have rarely extended for longer than a few days, so there is little information on potential long-term effects of exposure to small concentrations. This review considers the available evidence for long-term effects, based on laboratory and field data. Previous reviews of the literature from Germany and the USA are cited, prior to an assessment of the effects of individual VOCs. Although hydrocarbons from vehicle exhausts have been implicated in the observed effects on roadside vegetation, the evidence suggests that it is the nitrogen oxides in the exhaust gases that are mostly responsible. There is evidence that aromatic hydrocarbons can be metabolised in plants, although the fate of the metabolites is not known. There is a large literature on the effects of ethylene, because of its role as a plant hormone. Effects have been reported in the field, in response to industrial emissions, and dose-response experiments over several weeks in laboratory studies have clearly identified the potential for effects at ambient concentrations. The main responses are morphological (e.g. epinasty), which may be reversible, and on the development of flowers and fruit. Effects on seed production may be positive or negative, depending on the exposure concentration. Chlorinated hydrocarbons have been identified as potentially harmful to vegetation, but only one long-term experiment has studied dose-response relationships. As for ethylene, the most sensitive indication of effect was on seed production, although long-term accumulation of trichloroacetic acid in tissue may also be a problem. There is little evidence of the direct effects of oxygenated hydrocarbons on plants. Plants are a significant emission source of short-chain alcohols, aldehydes and ketones. Peroxyacetyl nitrate (PAN) has a well-documented history as damaging to vegetation. There have been few long-term experimental studies despite the field evidence for damaging effects. Early studies in California have been followed by more recent data from east Asia, but there is still a dearth of information on the potential for effects of PAN and related peroxyacyl nitrates on vegetation typical of regions around tropical and sub-tropical cities where PAN pollution is increasingly important. The lack of long-term measurements, coupled with the available evidence that effects are not linearly related to 'dose' measured as the product of exposure concentration and time, means that the possibility of adverse effects of VOCs on vegetation cannot be safely rejected, particularly in urban and industrial areas. Although reproductive processes (flowering, seed production) appear to be most sensitive, there have been no experimental studies on subsequent seed viability and the consequences at the ecosystem level of changes to plant phenology. The potential for VOC metabolites to accumulate in plant tissue has been demonstrated, but any subsequent effects on herbivores and phytophagous insects have yet to be investigated. PMID:12535603

Cape, J N

2003-01-01

194

The role of low volatile organics on secondary organic aerosol formation  

NASA Astrophysics Data System (ADS)

Large-scale atmospheric models, which typically describe secondary organic aerosol (SOA) formation based on chamber experiments, tend to systematically underestimate observed organic aerosol burdens. Since SOA constitutes a significant fraction of atmospheric aerosol, this discrepancy translates to an underestimation of SOA contribution to climate. Here we show that the underestimation of SOA yields can partly be explained by wall-losses of SOA forming compounds during chamber experiments. We present a chamber experiment where ?-pinene and ozone are injected in a Teflon chamber. When these two compounds react, we observe rapid formation and growth of new particles. Theoretical analysis of this formation and growth event indicates rapid formation of oxidized organic compounds (OVOC) of very low volatility in the chamber. Although these OVOCs of very low volatility contribute to the growth of new particles, their mass will almost completely be depleted to the chamber walls during the experiment while the depletion of OVOCs of higher volatilities is less efficient. According to our model simulations, the volatilities of OVOC contributing to the new particle formation event are of the order of 10-5 ?g m-3.

Kokkola, H.; Yli-Piril, P.; Vesterinen, M.; Korhonen, H.; Keskinen, H.; Romakkaniemi, S.; Hao, L.; Kortelainen, A.; Joutsensaari, J.; Worsnop, D. R.; Virtanen, A.; Lehtinen, K. E. J.

2013-06-01

195

Identification of volatile organic compounds polluting the atmosphere  

SciTech Connect

For an exact evaluation of the state of man`s environment and to adopt preventive measures to reduce the effect of human influences on it, it is necessary to know the of pollutants entering the atmosphere from various industrial sources. Chromatography methods of analysis are used in most of the analytical methods proposed for the solution of this problem. They enable the identification of the individual substances or a number of compounds within a given class. The chromato-mass spectrometric (CMS) method using high performance capillary separation overcomes this limitation and makes it possible to identify a considerably larger number of organic pollutants of quite different types. At present a standard method is used in the USA for the determination of critical pollutants in the atmosphere of urban areas, which was developed by the Environmental Protection Agency. There are similar methods in operation in other countries.Investigations in this field are limited in character in the Soviet Union. The present work outlines the results of investigations carried out with respect to sampling and structural identification of volatile organic compounds in the atmosphere of urban areas. The methods are based on the principle of sorption of the organic pounds on a solid carrier with subsequent thermal desorption and transfer of the solid components to the chromatograph of a CMS system. Examples of the use of the adsorption concentration on Tenax type sorbents have been described in the literature. 6 refs., 3 figs., 3 tabs.

Zamureenko, V.A.; Matveev, A.K.; Shik, N.V. [A.N. Severtsov Inst. of Evolutionary Morphology and Animal Ecology, Moscow (Russian Federation)] [and others

1992-03-10

196

Maximization of volatile fatty acids production from alginate in acidogenesis.  

PubMed

In this study, the response surface methodology (RSM) was applied to determine the optimum fermentative condition of alginate with the respect to the simultaneous effects of alginate concentration and initial pH to maximize the production of total volatile fatty acids (TVFAs) and alcohols. The results showed that the alginate fermentation was significantly affected by initial pH than by alginate concentration and there was no interaction between the two variables. The optimum condition was 6.2g alginate/L and initial pH 7.6 with a maximum TVFAs yield of 37.1%. Acetic acids were the main constituents of the TVFAs mixtures (i.e., 71.9-95.5%), while alcohols (i.e., ethanol, butanol, and propanol) were not detected. PMID:24080441

Pham, Hong Duc; Seon, Jiyun; Lee, Seong Chan; Song, Minkyung; Woo, Hee-Chul

2013-08-30

197

Volatile organic compounds in storm water from a parking lot  

USGS Publications Warehouse

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.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.

Lopes, T. J.; Fallon, J. D.; Rutherford, D. W.; Hiatt, M. H.

2000-01-01

198

Production of PHA from starchy wastewater via organic acids  

Microsoft Academic Search

Polyhydroxyalkanoate (PHA) was produced from a starchy wastewater in a two-step process of microbial acidogenesis and acid polymerization. The starchy organic waste was first digested in a thermophilic upflow anaerobic sludge blanket (UASB) reactor to form acetic (6080%), propionic (1030%) and butyric (540%) acids. The total volatile fatty acids reached 4000 mg l?1 at a chemical oxygen demand (COD) loading

Jian Yu

2001-01-01

199

Nano-Ag-Nafion modified Pt electrode for oxidation of volatile organic compounds: an electrochemical study.  

PubMed

In this work, we describe Nano-Ag-Nafion coated pt electrode for oxidation of volatile organic compound (VOC), here acetaldehyde. Electrochemically synthesized Nano-Ag-Nafion film on Pt was analyzed by electrochemically in various electrolyte solutions like nitric acid, sulfuric acid, potassium nitrate, and potassium hydroxide for its stability. High stability of Nano-Ag-Nafion film appeared in potassium hydroxide medium among electrolyte solutions studied. Electrocatalysis of acetaldehyde was occurred only in acid and neutral medium. A catalytic oxidative peak during cathodic voltammetric reduction scan was observed at 1.75 V, which, unusual redox behavior, follows EC' reaction path way between electrogenerated Ag(II) and acetaldehyde. For Nano-Ag potential applicability, a calibration plot was drawn from various concentration range of acetaldehyde to check the maximum concentration level of acetaldehyde degradation in air. PMID:22103205

Muthuraman, G; Chung, Sang Joon; Moon, Il Shik

2011-08-01

200

[Assessment of the emission of volatile organic compounds from polyurethane foams].  

PubMed

The emission of 2,4- and 2,6-diaminotoluene, triethylenediamine, diethanolamine and other volatile organic compounds from polyurethane foams was examined in environmental chamber. Tested materials did not release of amines. The emission of total volatile organic compounds showed differences for polyurethane samples but did not exceed ecological standards. PMID:15493351

Pecka, Irena; Wiglusz, Renata; Sitko, Elzbieta; Nikel, Grazyna

2004-01-01

201

40 CFR 60.112 - Standard for volatile organic compounds (VOC).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112 Protection...Prior to May 19, 1978 § 60.112 Standard for volatile organic compounds (VOC). (a) The owner or operator of...

2013-07-01

202

40 CFR 60.312 - Standard for volatile organic compounds (VOC).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312 Protection...Coating of Metal Furniture § 60.312 Standard for volatile organic compounds (VOC). (a) On and after the date on...

2013-07-01

203

40 CFR 60.542a - Alternate standard for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection of...Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a) On and after the date on which...

2013-07-01

204

40 CFR 60.112a - Standard for volatile organic compounds (VOC).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Standard for volatile organic compounds (VOC). 60.112a Section 60.112a Protection...Prior to July 23, 1984 § 60.112a Standard for volatile organic compounds (VOC). (a) The owner or operator of...

2013-07-01

205

Chlorinated Volatile Organic CompoundsOld, However, Actual Analytical and Toxicological Problem  

Microsoft Academic Search

The interest in chlorinated volatile organic compounds is not a new task but still draws the attention of scientists. The role they play in human organism, is an important aspect to consider, since the development of analytical techniques and instrumental solutions gives new possibilities of their application in the analytics of volatile compounds and recognition of properties, so far impossible

El?bieta Dobrzy?ska; Ma?gorzata Po?niak; Ma?gorzata Szewczy?ska; Bogus?aw Buszewski

2010-01-01

206

Bioactive volatile organic compounds from Antarctic (sponges) bacteria.  

PubMed

Antarctic bacteria represent a reservoir of unexplored biodiversity, which, in turn, might be correlated to the synthesis of still undescribed bioactive molecules, such as antibiotics. In this work we have further characterized a panel of four marine Antarctic bacteria able to inhibit the growth of human opportunistic multiresistant pathogenic bacteria belonging to the Burkholderia cepacia complex (responsible for the 'cepacia' syndrome in Cystic Fibrosis patients) through the production of a set of microbial Volatile Organic Compounds (mVOCs). A list of 30 different mVOCs synthesized under aerobic conditions by Antarctic bacteria was identified by GC-SPME analysis. Cross-streaking experiments suggested that Antarctic bacteria might also synthesize non-volatile molecules able to enhance the anti-Burkholderia activity. The biosynthesis of such a mixture of mVOCs was very probably influenced by both the presence/absence of oxygen and the composition of media used to grow the Antarctic strains. The antimicrobial activity exhibited by Antarctic strains also appeared to be more related to their taxonomical position rather than to the sampling site. Different Bcc bacteria were differently sensitive to the 'Antarctic' mVOCs and this was apparently related neither to the taxonomical position of the different strains nor to their source. The genome sequence of three new Antarctic strains was determined revealing that only P. atlantica TB41 possesses some genes belonging to the nrps-pks cluster. The comparative genomic analysis performed on the genome of the four strains also revealed the presence of a few genes belonging to the core genome and involved in the secondary metabolites biosynthesis. Data obtained suggest that the antimicrobial activity exhibited by Antarctic bacteria might rely on a (complex) mixture of mVOCs whose relative concentration may vary depending on the growth conditions. Besides, it is also possible that the biosynthesis of these compounds might occur through still unknown metabolic pathways. PMID:23619351

Papaleo, Maria Cristiana; Romoli, Riccardo; Bartolucci, Gianluca; Maida, Isabel; Perrin, Elena; Fondi, Marco; Orlandini, Valerio; Mengoni, Alessio; Emiliani, Giovanni; Tutino, Maria Luisa; Parrilli, Ermenegilda; de Pascale, Donatella; Michaud, Luigi; Lo Giudice, Angelina; Fani, Renato

2013-04-22

207

Multiple microbial activities for volatile organic compounds reduction by biofiltration.  

PubMed

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

Civilini, Marcello

2006-07-01

208

A biogenic volatile organic compound emission inventory for Hong Kong  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOCs) in the atmosphere react to form ozone and secondary organic aerosols, which deteriorate air quality, affect human health, and indirectly influence global climate changes. The present study aims to provide a preliminary assessment of BVOC emissions in Hong Kong (HKSAR). Thriteen local tree species were measured for their isoprene emission potential. Tree distribution was estimated for country park areas based on field survey data. Plant emission data obtained from measurements and the literature, tree distribution estimation data, land use information, and meteorological data were combined to estimate annual BVOC emissions of 8.610 9 g C for Hong Kong. Isoprene, monoterpenes, and other VOCs contributed about 30%, 40%, and 30% of the estimated total annual emissions, respectively. Although hundreds of plant species are found in Hong Kong country parks, the model results indicate that only 10 tree species contribute about 76% of total annual VOC emissions. Prominent seasonal and diurnal variations in emissions were also predicted by the model. The present study lays a solid foundation for future local research, and results can be applied for studying BVOC emissions in nearby southern China and Asian regions that share similar climate and plant distributions.

Tsui, Jeanie Kin-Yin; Guenther, Alex; Yip, Wing-Kin; Chen, Feng

209

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

PubMed

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

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

2010-01-01

210

Alternatives to Automotive Consumer Products That Use Volatile Organic Compounds (VOC) and/or Chlorinated Organic Compound Solvents. Addendum.  

National Technical Information Service (NTIS)

This addendum to the document entitled 'Alternatives to Automotive Consumer Products that use Volatile Organic Compounds (VOC) and/or Chlorinated Organic Compound Solvents' presents the questionnaires that were filled out by the staff of the Institute for...

D. Wolf J. Zavadil M. Morris

2004-01-01

211

Draft Analytical Method for Determination of Acid Volatile Sulfide in Sediment. Determination of Acid Volatile Sulfide and Selected Simultaneously Extractable Metals in Sediment.  

National Technical Information Service (NTIS)

The method describes procedures for the determination of acid volatile sulfide (AVS) and for selected metals that are solubilized during the acidification step (simultaneously extracted metal, SEM). As a precipitant of toxic heavy metals, sulfide is impor...

H. E. Allen G. Fu W. Boothman D. M. Di Toro J. D. Mahony

1991-01-01

212

Analysis of low- and non-volatile organic substances in the environment  

SciTech Connect

Three analytical techniques were utilized for the analysis of low- and non-volatile organic materials in various environmental samples. Gas chromatography-mass spectrometry was used to characterize lipid materials extracted from atmospheric aerosol samples collected over the equatorial Pacific ocean. Although terrestrial-derived lipids were present, the major source of the aerosol lipids appeared to be local marine sources whereas previous reports of non-equatorial Pacific ocean aerosols indicated a major terrestrial source of lipids. A supercritical fluid chromatograph (SFC), with flame ionization and mass spectrometric detectors, was constructed for analysis of compound mixtures which could not be adequately separated by gas chromatography or liquid chromatography. One such application was the separation and quantitation of glycerol tetraether lipids of archaebacteria. A new theory of solute retention in SFC, in which entropy changes play a significant role, was also developed. Pattern recognition procedures were applied to pyrolysis-mass spectrometry (Py-MS) data for the characterization of complex non-volatile organic mixtures. In one study, Py-MS data were used to distinguish humic acids from fulvic acids in a varied suite of humic materials. Another Py-MS study involved the classification of southeast Asian environmental samples associated with yellow rain. The method classified samples as either pollen or bee feces with a 95% success rate.

DeLuca, S.J.

1986-01-01

213

Exogenous ACC enhances volatiles production mediated by jasmonic acid in lima bean leaves  

Microsoft Academic Search

We report the synergistic effects of exogenous 1-aminocyclopropane-1-carboxylic acid (ACC) and jasmonic acid (JA) on production of induced volatiles by excised lima bean leaves. Application of ACC alone to leaves induced trace amounts of volatiles. ACC positively affected three JA-induced volatiles, (E)- and (Z)-?-ocimene, and (Z)-3-hexenyl acetate. The ethylene inhibitor, silver thiosulfate, inhibited the production of these compounds. The results

Jun-ichiro Horiuchi; Gen-ichiro Arimura; Rika Ozawa; Takeshi Shimoda; Junji Takabayashi; Takaaki Nishioka

2001-01-01

214

Responses of Calves Fed Diets Supplemented with Different Sources of Nitrogen and with Volatile Fatty Acids  

Microsoft Academic Search

Responses of young calves to starters containing supplements as follows: (I) soybean meal (44%), (II) soybean meal and branched-chain volatile fatty acids, (III) urea, and (IV) urea and branched- chain volatile fatty acids were studied. Calf starters and high quality alfalfa hay were fed ad libitum. Calves fed starters containing supplements of soybean meal (I and II) gained faster (P

A. E. Miron; D. E. Otterby; V. G. Pursel

1968-01-01

215

Organic non-volatile memories from ferroelectric phase separated blends  

Microsoft Academic Search

Ferroelectric polarisation is an attractive physical property for non-volatile binary switching. The functionality of the targeted memory should be based on resistive switching. Conductivity and ferroelectricity however cannot be tuned independently. The challenge is to develop a storage medium in which the favourable properties of ferroelectrics such as bistability and non-volatility can be combined with the beneficial properties provided by

Kamal Asadi; Dago de Leeuw; Bert de Boer; Paul Blom

2009-01-01

216

A universal temperature controlled membrane interface for the analysis of volatile and semi-volatile organic compounds.  

PubMed

A universal temperature controlled membrane interface (TCMI) has been constructed for hollow-fibre membranes. The membrane temperature is controllable in the range -70 to 250 degrees C using an electric heater and a flow of cooled nitrogen or helium gas. Volatile and semi-volatile organic compounds may be detected either by continuous diffusion across the membrane or by in-membrane pre-concentration followed by thermal desorption into the detector. The TCMI interface is demonstrated in combination with mass spectrometry and GC-MS, for the determination of VOCs and SVOCs in aqueous and air samples and for the on-line monitoring of a bioreactor. PMID:14529022

Creaser, Colin S; Lamarca, David Gmez; dos Santos, Luisa M Freitas; New, Anthony P; James, Phillip A

2003-09-01

217

Implications of volatile fatty acid profile on the metabolic pathway during continuous sulfate reduction.  

PubMed

Volatile fatty acid (VFA) profile is an important parameter in anaerobic reactors because it enables the assessment of metabolic pathways. Volatile fatty acids were monitored during sulfate reduction in a UASB (upflow anaerobic sludge blanket) reactor treating 2g/L sulfate concentration and with the organic loading increasing from 3.5 kg COD/m(3)d to 5.9 kg COD/m(3)d, for a 1-day residence time. In the absence of recirculation, the best outcome (65% reduction) was noticed with the lowest organic loading (3.55 kg/m(3)d). When recirculation was applied, sulfate reduction yields increased to 89%, corresponding to a sulfate removal rate of 1.94 kg SO(4)(2-)/m(3)d. The reactor performance was discussed in relation to microbial diversity and metabolic pathways. At high organic loading, two metabolic pathways account for lactate degradation: (i) lactate is oxidized to acetate and carbon dioxide by the incomplete-oxidizer SRB (sulfate-reducing bacteria) Desulfomonas, Desulfovibrio, Desulfolobus, Desulfobulbus and Desulfotomaculum spp.; (ii) lactate is converted to acetate by fermenting bacteria such as Clostridium sp. High propionate concentrations imply that there are low sulfate reduction efficiencies. PMID:22459067

Bertolino, Sueli M; Rodrigues, Isabel C B; Guerra-S, Renata; Aquino, Srgio F; Leo, Versiane A

2012-03-28

218

Organic Acids by Ion Chromatography  

NASA Astrophysics Data System (ADS)

The presence of increased levels of various organic acids in physiological fluids such as serum, plasma, and urine has been correlated with a variety of diseases (1). Although some are rare, others such as lactic acidosis and hyperoxaluria are more widespread (2, 3). The estimation of organic acids in biological fluids has long been an analytical problem owing to the nature of the samples and the hydrophilic behavior of the various acids.

Rich, William E.; Johnson, Edward; Lois, Louis; Stafford, Brian E.; Kabra, Pokar M.; Marton, Laurence J.

219

Chemically-Resolved Volatility Measurements of Organic Aerosol from Different Sources  

NASA Astrophysics Data System (ADS)

A newly modified fast temperature-stepping thermodenuder (TD) was coupled to a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) for rapid quantification of chemically-resolved volatility of organic aerosols (OA) emitted from individual sources. The TD-AMS system was used to characterize primary OA (POA) from biomass burning, trash burning surrogates (paper and plastic), and meat cooking as well as chamber-generated secondary OA (SOA) from a-pinene and gasoline vapor. Almost all atmospheric models represent POA as non-volatile, with no allowance for evaporation upon heating or dilution, or condensation upon cooling. Our results indicate that all OAs observed show semi-volatile behavior and that most POAs are at least as volatile as SOA measured in urban environments. Biomass-burning OA (BBOA) exhibited a wide range of volatilities, but more often showed volatility similar to urban OA. Paper-burning resembles BBOA because of its high volatility and intermediate atomic oxygen-to-carbon (O/C) ratio, while meat-cooking OAs (MCOA) have consistently lower volatility than ambient OA. Chamber-generated SOA was significantly more volatile than urban SOA, challenging extrapolation of traditional laboratory volatility measurements to the atmosphere. Most OAs sampled show increasing O/C ratio and decreasing H/C (hydrogen-to-carbon) ratio with temperature, further indicating that more oxygenated OA components are less volatile.

Huffman, J. A.; Docherty, K. S.; Mohr, C.; Ulbrich, I. M.; Ziemann, P. J.; Onasch, T. B.; Jimenez, J. L.

2009-04-01

220

Membrane bioreactor for control of volatile organic compound emissions  

SciTech Connect

A membrane bioreactor system that overcomes many of the limitations of conventional compost biofilters is described. The system utilizes microporous hydrophobic hollow fiber membranes for mass transfer of volatile organic compounds (VOCs) from the gas phase to a microbially active liquid phase. The reactor design provides a high biomass concentration, a method for wasting biomass, and a method for addition of pH buffers, nutrients, cometabolites, and/or other amendments. A theoretical model is developed, describing mass transfer and biodegradation in the membrane bioreactor. Reactor performance was determined in a laboratory scale membrane bioreactor over a range of gas loading rates using toluene as a model VOC. Toluene removal efficiency was greater than 98% at an inlet concentration of 100 ppm, and a gas residence time of less than 2 s. Factors controlling bioreactor performance were determined through both experiments and theoretical modeling to include: compound Henry`s law constant, membrane specific surface area, gas and VOC loading rates, liquid phase turbulence, and biomass substrate utilization rate.

Ergas, S.J. [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Civil and Environmental Engineering; McGrath, M.S. [Monsanto Enviro-Chem Systems Inc., Chesterfield, MO (United States)

1997-06-01

221

Modeling Emissions of Volatile Organic Compounds from New Carpets  

SciTech Connect

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.

Little, J.C.; Hodgson, A.T.; Gadgil, A.J.

1993-02-01

222

Predicting flammability of gas mixtures containing volatile organic compounds  

SciTech Connect

One requirement regarding the transportation of transuranic (TRU) radioactive waste containers currently limits the total concentration of potentially flammable volatile organic compounds (VOCs) and flammable gases in the headspace of the waste container. Typical VOCs observed in the drums include aromatic hydrocarbons, ketones, alcohols, cyclohexane, as well as chlorinated hydrocarbons (alkanes and alkenes). Flammable gases, such as hydrogen and methane, may be generated in the containers by radiation-induced decomposition (radiolysis) of water and hydrocarbon waste forms. An experimental program was initiated to identify an accurate means for predicting flammability for gas mixtures containing one or more of the following species: hydrogen, carbon tetrachloride, 1,2-dichloroethane, toluene, or 2-butanone. The lower flammability limits (LFL) of gas mixtures containing equimolar quantity for each species were determined in a 19-liter laboratory flammability chamber using a strong spark ignition source. The group factor contribution method was determined to be more accurate than the LeChatelier method for estimating the LFL for these gas mixtures.

Liekhus, K. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Zlochower, I. [National Inst. for Occupational Safety and Health, Pittsburgh, PA (United States). Pittsburgh Research Lab.; Djordjevic, S.; Loehr, C. [Benchmark Environmental, Albuquerque, NM (United States)

1997-12-31

223

Indoor chemistry. Ozone, volatile organic compounds, and carpets  

SciTech Connect

Volatile organic compounds (VOCs) have been measured in a freshly carpeted 20-m[sup 3] stainless-steel room in both the absence and presence of ozone (ozone concentrations ranging from 30 to 50 ppb, with one experiment conducted at 400 ppb). Four different types of carpeting were exposed, and in each set of experiments, the room was ventilated at 1 air exchange/h. The gas-phase concentrations of selected carpet emissions (e.g., 4-phenylcyclohexene, 4-vinylcyclohexene, and styrene) significantly decreased in the presence of ozone. Conversely, the concentrations of other compounds (e.g., formaldehyde, acetaldehyde, and aldehydes with between 5 and 10 carbons) significantly increased. Furthermore, the total concentration of VOCs increased markedly in the presence of ozone. The additional VOCs appear to have been generated by reactions between ozone and relatively nonvolatile compounds associated with the carpets. These studies suggest that VOCs measured within a building at elevated ozone levels (>30 ppb) may differ from those measured at lower ozone levels (<10 ppb). 12 refs., 2 figs., 6 tabs.

Weschler, C.J. (Bell Communications Research, Red Bank, NJ (United States)); Hodgson, A.T.; Wooley, J.D. (Lawrence Berkeley Lab., CA (United States))

1992-12-01

224

Degradation of volatile organic compounds with thermally activated persulfate oxidation.  

PubMed

This study investigated the extent and treatability of the degradation of 59 volatile organic compounds (VOCs) listed in the EPA SW-846 Method 8260B with thermally activated persulfate oxidation. Data on the degradation of the 59 VOCs (in mixture) reacted with sodium persulfate in concentrations of 1 g l(-1) and 5 g l(-1) and at temperatures of 20 degrees C, 30 degrees C, and 40 degrees C were obtained. The results indicate that persulfate oxidation mechanisms are effective in degrading many VOCs including chlorinated ethenes (CEs), BTEXs and trichloroethanes that are frequently detected in the subsurface at contaminated sites. Most of the targeted VOCs were rapidly degraded under the experimental conditions while some showed persistence to the persulfate oxidation. Compounds with "CC" bonds or with benzene rings bonded to reactive functional groups were readily degraded. Saturated hydrocarbons and halogenated alkanes were much more stable and difficult to degrade. For those highly persulfate-degradable VOCs, degradation was well fitted with a pseudo first-order decay model. Activation energies of reactions of CEs and BTEXs with persulfate were determined. The degradation rates increased with increasing reaction temperature and oxidant concentration. Nevertheless, to achieve complete degradation of persulfate-degradable compounds, the systems required sufficient amounts of persulfate to sustain the degradation reaction. PMID:16202809

Huang, Kun-Chang; Zhao, Zhiqiang; Hoag, George E; Dahmani, Amine; Block, Philip A

2005-04-12

225

Analysis of volatile organic compounds released during food decaying processes.  

PubMed

A number of volatile organic compounds (VOCs) including acetone, methyl ethyl ketone, toluene, ethylbenzene, m,p-xylene, styrene, and o- xylene released during food decaying processes were measured from three types of decaying food samples (Kimchi (KC), fresh fish (FF), and salted fish (SF)). To begin with, all the food samples were contained in a 100-mL throwaway syringe. These samples were then analyzed sequentially for up to a 14-day period. The patterns of VOC release contrasted sharply between two types of fish (FF and SF) and KC samples. A comparison of data in terms of total VOC showed that the mean values for the two fish types were in the similar magnitude with 280 579 (FF) and 504 1,089 ppmC (SF), while that for KC was much lower with 16.4 7.6 ppmC. There were strong variations in VOC emission patterns during the food decaying processes between fishes and KC that are characterized most sensitively by such component as styrene. The overall results of this study indicate that concentration levels of the VOCs differed significantly between the food types and with the extent of decaying levels through time. PMID:21541778

Phan, Nhu-Thuc; Kim, Ki-Hyun; Jeon, Eui-Chan; Kim, Uk-Hun; Sohn, Jong Ryeul; Pandey, Sudhir Kumar

2011-05-04

226

A biogenic volatile organic compounds emission inventory for Yunnan Province.  

PubMed

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

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

2005-01-01

227

Constituents of volatile organic compounds of evaporating essential oil  

NASA Astrophysics Data System (ADS)

Essential oils containing aromatic compounds can affect air quality when used indoors. Five typical and popular essential oilsrose, lemon, rosemary, tea tree and lavenderwere 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.

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

2009-12-01

228

Predicting the emission rate of volatile organic compounds fromvinyl flooring  

SciTech Connect

A model for predicting the rate at which a volatile organic compound (VOC) is emitted from a diffusion-controlled material is validated for three contaminants (n-pentadecane, n-tetradecane, and phenol) found in vinyl flooring (VF). Model parameters are the initial VOC concentration in the material-phase (C{sub 0}), the material/air partition coefficient (K), and the material-phase diffusion coefficient (D). The model was verified by comparing predicted gas-phase concentrations to data obtained during small-scale chamber tests, and by comparing predicted material-phase concentrations to those measured at the conclusion of the chamber tests. Chamber tests were conducted with the VF placed top side up and bottom side up. With the exception of phenol, and within the limits of experimental precision, the mass of VOCs recovered in the gas phase balances the mass emitted from the material phase. The model parameters (C{sub 0}, K, and D) were measured using procedures that were completely independent of the chamber test. Gas- and material-phase predictions compare well to the bottom-side-up chamber data. The lower emission rates for the top-side-up orientation may be explained by the presence of a low-permeability surface layer. The sink effect of the stainless steel chamber surface was shown to be negligible.

Cox, Steven S.; Little, John C.; Hodgson, Alfred T.

2001-03-01

229

[Volatile organic compounds (VOCs) emitted from large furniture].  

PubMed

Indoor air pollution by volatile organic compounds (VOCs), which may cause a hazardous influence on human being such as sick building (sick house) syndrome, has become a serious problem. In this study, VOCs emitted from nine pieces of home furniture, three sets of dining tables, three sets of chest of drawers and three sofas, were analyzed as potential sources of indoor air pollution by large chamber test method (JIS A 1911). Based on the emission rates of total VOC (TVOC), the impacts on the indoor TVOC was estimated by the sample model with a volume of 20 m3 and ventilation frequency of 0.5 times/h. The estimated TVOC increment values were exceeded the provisional target value for indoor air (400 microg/m3) in three sets of dining tables, one set of chest of drawer and one sofa. The estimated increment of formaldehyde were exceeded the guideline value (100 microg/m3) in one set of dining table, two sets of chest of drawers and one sofa. These results revealed that VOC emissions from furniture may influence significantly indoor air quality. Also, in this study, to establish the alternative method for large chamber test methods, emission rates from representative three parts of furniture unit were evaluated using the small chamber and emission rate from full-sized furniture was predicted. Emission rates of TVOC and formaldehyde predicted by small chamber test were 3-46% and 6-252% of the data obtained using large chamber test, respectively. PMID:22259846

Tanaka-Kagawa, Toshiko; Furuta, Mitsuko; Shibatsuji, Masayoshi; Jinno, Hideto; Nishimura, Tetsuji

2011-01-01

230

Advanced heat pump for the recovery of volatile organic compounds  

SciTech Connect

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.

Not Available

1992-03-01

231

Effect of phenolic acids on glucose and organic acid metabolism by lactic acid bacteria from wine.  

PubMed

The influence of phenolic (p-coumaric, caffeic, ferulic, gallic and protocatechuic) acids on glucose and organic acid metabolism by two strains of wine lactic acid bacteria (Oenococcus oeni VF and Lactobacillus hilgardii 5) was investigated. Cultures were grown in modified MRS medium supplemented with different phenolic acids. Cellular growth was monitored and metabolite concentrations were determined by HPLC-RI. Despite the strong inhibitory effect of most tested phenolic acids on the growth of O. oeni VF, the malolactic activity of this strain was not considerably affected by these compounds. While less affected in its growth, the capacity of L. hilgardii 5 to degrade malic acid was clearly diminished. Except for gallic acid, the addition of phenolic acids delayed the metabolism of glucose and citric acid in both strains tested. It was also found that the presence of hydroxycinnamic acids (p-coumaric, caffeic and ferulic) increased the yield of lactic and acetic acid production from glucose by O. oeni VF and not by L. hilgardii 5. The results show that important oenological characteristics of wine lactic acid bacteria, such as the malolactic activity and the production of volatile organic acids, may be differently affected by the presence of phenolic acids, depending on the bacterial species or strain. PMID:19376463

Campos, Francisco M; Figueiredo, Ana R; Hogg, Tim A; Couto, Jos A

2009-02-07

232

Source apportionment modeling of volatile organic compounds in streams.  

PubMed

It often is of interest to understand the relative importance of the different sources contributing to the concentration c(w) of a contaminant in a stream; the portions related to sources 1, 2, 3, etc. are denoted c(w,1), c(w2), c(w3), etc. Like c(w), the fractions alpha1 = c(w,1)/c(w), alpha2 = c(w,2)/c(w), alpha3 = c(w,3)/c(w), 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 c(w). Rule 2: VOC loss by volatilization, flow loss to groundwater, in-stream degradation, etc. is distributed over c(w,1), c(w,2), c(w3), etc. in proportion to their corresponding alpha 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 c(w) values approaching the common water quality guideline range of 1 to 10 microg/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 alpha(j) for the compound remain unchanged over that section while c(w) decreases. A characteristic time tau(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 contamination at points of interest along a stream. PMID:16629131

Pankow, James F; Asher, William E; Zogorski, John S

2006-04-01

233

Controlled exposures to volatile organic compounds in sensitive groups.  

PubMed

Sensitivities to chemicals are characterized by symptoms in multiple organ systems in response to low-level chemical exposures. This paper reviews studies of controlled exposures to odorants and to mixtures of volatile organic compounds. Sensitive subgroups include subjects who met Cullen's 1987 criteria for multiple chemical sensitivity (MCS), Gulf War veterans with chronic fatigue syndrome and chemical sensitivity (CFS/CS), and subjects with specific self-reported sensitivities to methyl terbutyl ether (MTBE) in gasoline (MTBE-sensitive). All studies include comparison of age- and sex-matched healthy controls. Studies of olfaction did not support unusual sensitivity, defined as lower odor thresholds, among MCS subjects; however, a dose-response pattern of symptoms was observed in response to suprathreshold concentrations of phenyl ethyl alcohol. In blinded, controlled exposures to clean air, gasoline, gasoline/11% MTBE, and gasoline/15% MTBE, a threshold effect was observed with MTBE-sensitive subjects reporting significantly increased symptoms to gasoline/15% MTBE exposure. Autonomic arousal (heart and respiration rate; end-tidal CO2) in response to odor of chemical mixtures may mediate symptoms for subjects with generalized chemical sensitivities, but not for those whose sensitivities are confined to specific chemicals. For example, Gulf War veterans with CFS/CS experienced reduced end-tidal CO2 when exposed to diesel fumes, while exposure to MTBE did not produce any psychophysiologic changes in MTBE-sensitive subjects. Controlled olfactory and exposure studies reveal that significant responses can be observed in chemically sensitive subjects even when de-adaptation has not occurred. However, these studies suggest that symptoms are not necessarily accompanied by changes in physiologic arousal. Subject characteristics play a critical role in outcomes. PMID:12000025

Fiedler, N; Kipen, H M

2001-03-01

234

On the flux of oxygenated volatile organic compounds from organic aerosol oxidation  

NASA Astrophysics Data System (ADS)

Previous laboratory and field studies suggest that oxidation of organic aerosols can be a source of oxygenated volatile organic compounds (OVOC). Using measurements of atmospheric oxidants and aerosol size distributions performed on the NASA DC-8 during the INTEX-NA campaign, we estimate the potential magnitude of the continental summertime OVOC flux from organic aerosol oxidation by OH to be as large as ~70 pptv C/day in the free troposphere. Contributions from O3, H2O2, photolysis, and other oxidants may increase this estimate. These processes may provide a large, diffuse source of OVOC that has not been included in current atmospheric models, and thus have a significant impact on our understanding of organic aerosol, OVOC, PAN, and HOx chemistry. The potential importance and highly uncertain nature of our estimate highlights the need for more field and laboratory studies on organic aerosol composition and aging.

Kwan, Alan J.; Crounse, John D.; Clarke, Antony D.; Shinozuka, Yohei; Anderson, Bruce E.; Crawford, James H.; Avery, Melody A.; McNaughton, Cameron S.; Brune, William H.; Singh, Hanwant B.; Wennberg, Paul O.

2006-08-01

235

Role of volatile fatty acids in colonization resistance to Clostridium difficile.  

PubMed Central

The in vitro inhibition of Clostridium difficile by volatile fatty acids was correlated with the pH and concentrations of volatile fatty acids in the ceca of hamsters of different ages. The concentrations of cecal volatile fatty acids increased with the age of the animals. Maximum concentrations of individual volatile fatty acids were attained when the animals were ca. 19 days old, with acetic, propionic, and butyric acids occurring in the highest concentrations (72, 16, and 32 microequivalents/g of cecum, respectively). The cecal pH was approximately the same in hamsters of all ages (pH 6.6 to 7.0). Only butyric acid reached a concentration in the ceca of hamsters which was inhibitory to the in vitro multiplication of C. difficile. This inhibitory concentration was attained when the animals were ca. 19 days of age. When mixtures of volatile fatty acids were prepared at concentrations equal to those present in the ceca of hamsters, there was a direct correlation between the in vitro inhibitory activity of the volatile fatty acids and the susceptibility of hamsters 4 days of age or older to C. difficile intestinal colonization. The resistance of hamsters less than 4 days of age to C. difficile intestinal colonization appears to be due to factors other than volatile fatty acids.

Rolfe, R D

1984-01-01

236

Transport and fate of volatile organic chemicals in unsaturated, nonisothermal, salty porous media  

Microsoft Academic Search

A wide variety of volatile organic chemicals (VOC) have been applied to agricultural land or buried in chemical waste sites. The fate of these chemicals depends upon several mechanisms such as sorption, degradation, and transport in liquid and gaseous phases. Understanding the transport mechanisms affecting the volatile chemicals can lead to better management strategies. A theory describing inorganic solute transport,

I. N Nassar; Robert Horton

1999-01-01

237

Engineered endophytic bacteria improve phytoremediation of water-soluble, volatile, organic pollutants  

Microsoft Academic Search

Phytoremediation of highly water soluble and volatile organic xenobiotics is often inefficient because plants do not completely degrade these compounds through their rhizospheres. This results in phytotoxicity and\\/or volatilization of chemicals through the leaves, which can cause additional environmental problems. We demonstrate that endophytic bacteria equipped with the appropriate degradation pathway improve the in planta degradation of toluene. We introduced

Tanja Barac; Safiyh Taghavi; Brigitte Borremans; Ann Provoost; Licy Oeyen; Jan V Colpaert; Jaco Vangronsveld; Daniel van der Lelie

2004-01-01

238

Assessing the fate of biodegradable volatile organic contaminants in unsaturated soil filter systems  

Microsoft Academic Search

The assessment of contaminant biodegradation in the subsurface is challenged by various abiotic processes leading to a reduction of contaminant concentration without a destructive mass removal of the contaminant. In unsaturated porous media, this interplay of processes is further complicated by volatilization. Many organic contaminants are sufficiently volatile to allow for significant fluxes from the water phase into the soil

Martin Thullner; Cecilia de Biase; Joanna Hanzel; Daniel Reger; Lukas Wick; Sascha Oswald; Manfred van Afferden; Axel Schmidt; Nils Reiche; Sven Jechalke

2010-01-01

239

Emission of Ozone and Organic Volatiles from a Selection of Laser Printers and Photocopiers  

Microsoft Academic Search

To estimate the impact of office equipment on the quality of indoor air, the emission of ozone and organic volatiles was measured from one photocopier and four laser printers, three of which operated according to traditional corona discharge technology. The laser printers equipped with traditional technology emitted significant amounts of ozone and formaldehyde. Lesser amounts of other volatile aldehydes were

Tapani Tuomi; Bernt Engstrm; Raimo Niemel; Juha Svinhufvud; Kari Reijula

2000-01-01

240

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...

241

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...

242

A batch reactor for monitoring process dynamics during biodegradation of volatile organics  

Microsoft Academic Search

Data are presented that demonstrate a batch reactor that allows accurate monitoring of process dynamics during biodegradation of volatile organics. Using this system, many samples can be removed in an aseptic fashion, allowing frequent measurements of the concentrations of biomass, electron donors, electron acceptors, and volatile compounds. Additionally, the reactor is well instrumented, allowing the continuous monitoring of pH, oxidation\\/reduction

Rodney S. Skeen; M. J. Truex; J. N. Petersen; J. S. Hill

1994-01-01

243

A dynamic two-dimensional system for measuring volatile organic compound volatilization and movement in soils.  

PubMed

There is an important need to develop instrumentation that allows better understanding of atmospheric emission of toxic volatile compounds associated with soil management. For this purpose, chemical movement and distribution in the soil profile should be simultaneously monitored with its volatilization. A two-dimensional rectangular soil column was constructed and a dynamic sequential volatilization flux chamber was attached to the top of the column. The flux chamber was connected through a manifold valve to a gas chromatograph (GC) for real-time concentration measurement. Gas distribution in the soil profile was sampled with gas-tight syringes at selected times and analyzed with a GC. A pressure transducer was connected to a scanivalve to automatically measure the pressure distribution in the gas phase of the soil profile. The system application was demonstrated by packing the column with a sandy loam in a symmetrical bed-furrow system. A 5-h furrow irrigation was started 24 h after the injection of a soil fumigant, propargyl bromide (3-bromo-1-propyne; 3BP). The experience showed the importance of measuring lateral volatilization variability, pressure distribution in the gas phase, chemical distribution between the different phases (liquid, gas, and sorbed), and the effect of irrigation on the volatilization. Gas movement, volatilization, water infiltration, and distribution of degradation product (Br-) were symmetric around the bed within 10%. The system saves labor cost and time. This versatile system can be modified and used to compare management practices, estimate concentration-time indexes for pest control, study chemical movement, degradation, and emissions, and test mathematical models. PMID:12175024

Allaire, S E; Yates, S R; Ernst, F F; Gan, J

244

Adsorption of volatile organic compounds onto activated carbon cloths derived from a novel regenerated cellulosic precursor.  

PubMed

Activated carbon cloths (ACC) were prepared from lyocell, a novel regenerated cellulose nanofibre fabric, by phosphoric acid activation in inert atmosphere at two different final thermal treatment temperatures (864 and 963 degrees C). Benzene, toluene and n-hexane isotherms at 298 and 273K were measured in order to gain insight into the porous structure of the ACC and to evaluate their performance for the removal of volatile organic compounds (VOCs). The Dubinin-Radushkevich equation was employed to evaluate textural parameters of the ACC. The textural characteristics of the ACC were compared with those previously determined from nitrogen (77K) and carbon dioxide (273K) adsorption data. The samples were essentially microporous. The textural parameters calculated from the hydrocarbon isotherms were in good agreement with those evaluated from nitrogen isotherms for the ACC with the wider microporosity. Additionally, the Freundlich model provided a good description of the experimental isotherms for the three volatile organic compounds. The ACC obtained at the higher temperature exhibited a larger adsorption capacity. The ACC were also electrically conductive and showed potential for regeneration by the Joule effect, as determined from macroscopic electrical measurements before and after n-hexane adsorption. PMID:20042290

Ramos, M E; Bonelli, P R; Cukierman, A L; Ribeiro Carrott, M M L; Carrott, P J M

2009-12-11

245

A global model of natural volatile organic compound emissions  

NASA Astrophysics Data System (ADS)

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 (0.50.5 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.

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

246

A biogenic volatile organic compounds emission inventory for Beijing  

NASA Astrophysics Data System (ADS)

The present study presents us the first detailed inventory for volatile organic compounds (VOC) emissions from vegetation over Beijing, China. 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 and photosynthetic active radiation (PAR) data from direct real-time measurement. The inventory has a spatial resolution of 11 km2 and a time resolution of 1 h. Urban, agriculture, and natural land-use distributions in Beijing 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. Twenty-three kinds of the emission rate data of the 39 vegetation types in Beijing were identified using a bag-enclosure sampling method followed by GC-FID analysis in our field measurement. Other emission rate data were quoted from previous study or assigned with the taxonomic method. Correcting for environmental factors, including light intensity and temperature, we arrive a value of 1.610 10 g C for total annual biogenic VOC emissions from Beijing, including 7.910 9 g C for isoprene, 3.510 9 g C for monoterpenes, and 4.810 9 g C for OVOC. Some uncertainties are also discussed in this study.

Zhihui, Wang; Yuhua, Bai; Shuyu, Zhang

247

Identification and Quantification of Volatile Organic Compounds at a Dairy  

NASA Astrophysics Data System (ADS)

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.

Filipy, J.; Mount, G.; Westberg, H.; Rumburg, B.

2003-12-01

248

Magmatic MORB Volatiles, Seafloor Hydrothermal Systems and Abiotic Organic Synthesis  

NASA Astrophysics Data System (ADS)

A plausible model for the origin of the observed C-O-H volatiles observed in MORB glasses is that they were incorporated in primary melts of the upwelling mantle. Based on the observed ferric/ferrous ratios in MORB glass, it is probable that the MORB source mantle contained diamond or graphite, depending on pressure. If true, then during partial mantle melting the graphite/diamond would react with FeO1.5 in garnet/spinel and clinopyroxene to form CO2 which would dissolve in the melt as carbonate ion. Using equation of state models for CO2 activity and ferric/ferrous ratios in the magma it is possible to model the amount of carbonate dissolved in the basaltic magma as a function of the degree of melting (Holloway and O'Day, 2000). The results require that rising MORB magma will become saturated in CO2 at depths much greater than those proposed for MORB magma chambers. Conversely H2O values observed in MORB glasses are far below saturation. However as CO2 reaches saturation and exsolves from the melt the low fO2 imposed by the low ferric/ferrous ratio results in a high H2/H2O ratio in the exsolving supercritical fluid. We have shown that fluids with this composition produce methanol (CH3OH) in the presence of magnetite at seafloor hydrothermal P-T conditions in a flow-through system (Voglesonger, et al., 2001) and that aqueous methanol solutions react in montmorillonite clay interlayers to form a wide variety of complex hydrocarbon molecules, the most abundant being hexamethyl benzene (Williams, et al., 2005). Methyl stearate (C17H35COOCH3) was also observed in moderate amounts. Holloway, J. R. and P. A. O'Day (2000). "Production of CO2 and H2 by Diking-Eruptive Events at Mid-Ocean Ridges: Implications for Abiotic Organic Synthesis and Global Geochemical Cycling." International Geology Review 42: 673-683. Voglesonger, K. M., J. R. Holloway, E. E. Dunn, P. J. Dalla-Betta and P. A. O'Day (2001). "Experimental Abiotic Synthesis of Methanol in Seafloor Hydrothermal Systems." Chemical Geology 180: 129-139. Williams, L. B., B. C. Canfield, K. M. Voglesonger and J. R. Holloway (2005). "Organic molecules formed in a primordial womb." Geology 33: 913-916.

Holloway, J. R.

2007-12-01

249

Exchange of volatile organic compounds in the boreal forest floor  

NASA Astrophysics Data System (ADS)

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 consideration when assessing ecosystem level VOC fluxes. These results can be utilized also in air chemistry models, which are almost entirely lacking the below-canopy compartment. Kulmala, M., Suni, T., Lehtinen, K.E.J., Dal Maso, M., Boy, M., Reissell, A., Rannik, ., Aalto, P., Keronen, P., Hakola, H., Bck, J., Hoffmann, T., Vesala, T. & Hari, P. 2004. A new feedback mechanism linking forests, aerosols, and climate. Atmospheric Chemistry and Physics 4: 557-562.

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

2013-04-01

250

Neurotoxic Effects of Controlled Exposure to a Complex Mixture of Volatile Organic Compounds.  

National Technical Information Service (NTIS)

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 (VOCs) found in new buildings. 66 normal healt...

D. A. Otto L. Molhave H. K. Hudnell G. Goldstein J. O'Neil

1990-01-01

251

Preliminary evaluation of selected in situ remediation technologies for Volatile Organic Compound contamination at Arid sites.  

National Technical Information Service (NTIS)

To support the Volatile Organic Compounds-Arid Site (VOC-Arid) Integrated Demonstration (ID) in its technical, logistical, institutional, and economical testing of emerging environmental management and restoration technologies. Pacific Northwest Laborator...

R. J. Lenhard M. A. Gerber J. E. Amonette

1992-01-01

252

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 ...

253

Development of a Universally Accepted Test Method for Volatile Organic Compounds.  

National Technical Information Service (NTIS)

Test methods published by the American Society for Testing and Materials (ASTM) and used for the determination of Volatile Organic Compound (VOC) content of coatings are known to have cumulatively poor reproducibility. The VOC calculations are contained i...

D. P. Fairley R. Gill R. Haffner

1991-01-01

254

PERTURBATION OF VOLTAGE-SENSITIVE Ca2+ CHANNEL FUNCTION BY VOLATILE ORGANIC SOLVENTS.  

EPA Science Inventory

The mechanisms underlying the acute neurophysiological and behavioral effects of volatile organic compounds (VOCs) remain to be elucidated. However, the function of neuronal ion channels is perturbed by VOCs. The present study examined effects of toluene (TOL), trichloroethylene ...

255

76 FR 41086 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...  

Federal Register 2010, 2011, 2012, 2013

...Volatile Organic Compound Reinforced Plastic Composites Production Operations Rule...compound (VOC) emissions from reinforced plastic composites production operations. This...applies to any facility that has reinforced plastic composites production operations....

2011-07-13

256

Ground Water Supply Survey. Summary of Volatile Organic Contaminant Occurrence Data.  

National Technical Information Service (NTIS)

The document summarizes a sampling and analysis program on finished water from 945 water supplies which use underground sources. The program was conducted in order to strengthen the volatile organic chemical occurrence data base and to encourage state inv...

J. J. Westrick J. W. Mello R. F. Thomas

1983-01-01

257

Analysis of Ambient Polar Volatile Organic Compounds Using Chemical Ionization-Ion Trap Detector.  

National Technical Information Service (NTIS)

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 refocusing onto a column for analysis by capillary gas chrom...

S. M. Gordon M. Miller

1989-01-01

258

FIELD EVALUATION OF A SIMPLE MICROCOSM SIMULATING THE BEHAVIOR OF VOLATILE ORGANIC COMPOUNDS IN SUBSURFACE MATERIALS  

EPA Science Inventory

A simple batch microcosm had previously been developed to simulate the behavior of volatile organic compounds in unconsolidated subsurface material. The microcosm was evaluated by comparing the behavior of tetrachloroethylene, bromoform, carbon tetrachloride, 1,2-dichlorobenzene,...

259

Field Strategy for Sorting Volatile Organics into Source-Related Groups.  

National Technical Information Service (NTIS)

A new monitoring strategy, referred to as temporal profile analysis (TPA), has been developed. TPA uses fixed-site, ambient air monitoring of volatile organic compounds (VOCs) to determine the number, VOC composition, and approximate trajectories of nearb...

W. A. McClenny K. D. Oliver J. D. Pleil

1989-01-01

260

IMPROVED METHOD FOR THE STORAGE OF GROUND WATER SAMPLES CONTAINING VOLATILE ORGANIC ANALYTES  

EPA Science Inventory

The sorption of volatile organic analytes from water samples by the Teflon septum surface used with standard glass 40-ml sample collection vials was investigated. Analytes tested included alkanes, isoalkanes, olefins, cycloalkanes, a cycloalkene, monoaromatics, a polynuclear arom...

261

FACTORS CONTROLLING THE EMISSIONS OF MONOTERPENES AND OTHER VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

Plants contain a number of volatile organic compounds, including isoprene, mono- and sesquiterpenes, alcohols, aldehydes, ketones, and esters. ndividual plant species have unique combinations of these compounds; consequently, the emission pattern for each species is also specific...

262

Performance specifications for technology development: Application for characterization of volatile organic compounds in the environment.  

National Technical Information Service (NTIS)

This report contains information about technology development for the monitoring and remediation of environmental pollution caused by the release of volatile organic compounds. Topics discussed include: performance specification processes, gas chromatogra...

S. E. Carpenter P. V. Doskey M. D. Erickson P. C. Lindahl

1994-01-01

263

Total Exposure and Risk Assessment for Drinking Water Contaminated with Volatile Organic Compounds.  

National Technical Information Service (NTIS)

A total exposure and cancer risk assessment was conducted on nine volatile organic compounds (VOCs) frequently found in contaminated drinking water. Routes of exposure considered in the analysis included ingestion, inhalation and dermal uptake. A total of...

J. M. Clark C. L. Fuller

1987-01-01

264

Organic Polychloride Microanalysis: A Guide to Volatiles and Multichlorinates in the Oxygen Flask.  

National Technical Information Service (NTIS)

The degree of chlorination of an organic material affects both its volatility and resistance to oxidation. Each of these properties makes difficult the selection of a quantitative means of mineralization for elemental microanalysis. Since the analysis for...

J. M. Corliss N. B. Scholtz T. E. Wollner

1972-01-01

265

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...

266

VOLATILE ORGANIC COMPOUNDS IN INDOOR AIR: A SURVEY OF VARIOUS STRUCTURES  

EPA Science Inventory

Co-workers collected indoor air samples in their homes in SUMMA polished canisters. Upon receipt in the laboratory, the whole air samples were analyzed for volatile organic compounds (VOCs) using cryogenic sample preconcentration and subsequent capillary column chromatography. Ea...

267

National Ambient Volatile Organic Compounds (VOCs) Data Base, 1970-1987 (for Microcomputers),  

National Technical Information Service (NTIS)

The National Ambient Volatile Organic Compounds (VOCs) Data Base update is the result of an ongoing effort to gather, evaluate, and compile the measured concentrations of a large number of VOCs. Data on the observed concentrations of three hundred twenty ...

J. J. Shah L. T. Cupitt

1987-01-01

268

Interlaboratory Study of a Test Method for Measuring Total Volatile Organic Compound Content of Consumer Products.  

National Technical Information Service (NTIS)

Consumer products are potentially significant sources of volatile organic compounds (VOCs), which contribute to formation of ozone in photochemical smog. Currently, the U.S Environmental Protection Agency (EPA) has no approved method for measuring the VOC...

E. E. Rickman G. B. Howe R. K. M. Jayanty

1995-01-01

269

INTERLABORATORY STUDY OF A TEST METHOD FOR MEASURING TOTAL VOLATILE ORGANIC COMPOUND CONTENT OF CONSUMER PRODUCTS  

EPA Science Inventory

The report describes results of an interlaboratory study to estimate repeatability (precision of analyses performed by a single laboratory) and reproducibility (precision analyses performed by different laboratories) of a consumer products volatile organic compound (VOC) measurem...

270

EXPOSURE OF HUMANS TO A VOLATILE ORGANIC MIXTURE: I. BEHAVIORAL ASSESSMENT  

EPA Science Inventory

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

271

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-...

272

PERTURBATION OF VOLTAGE-SENSITIVE CALCIUM FUNCTION IN PHEOCHROMOCYTOMA CELLS BY VOLATILE ORGANIC SOLVENTS.  

EPA Science Inventory

Volatile organic solvents such as toluene (TOL) and trichloroethylene perturb nervous system function and share characteristic effects with other central nervous system depressants such as anesthetic gasses, ethanol, benzodiazepines and barbiturates. Recently, mechanistic studies...

273

EVALUATION OF SOLID ADSORBENTS FOR THE COLLECTION AND ANALYSES OF AMBIENT BIOGENIC VOLATILE ORGANICS  

EPA Science Inventory

Micrometeorological flux measurements of biogenic volatile organic compounds (BVOCs) usually require that large volumes of air be collected (whole air samples) or focused during the sampling process (cryogenic trapping or gas-solid partitioning on adsorbents) in order to achiev...

274

CONTROL OF INDUSTRIAL VOC (VOLATILE ORGANIC COMPOUND) EMISSIONS BY CATALYTIC INCINERATION. VOLUME 9. QUALITY ASSURANCE  

EPA Science Inventory

Radian Corporation, under contract to the U.S. Environmental Protection Agency, performed site selection, test plan development, and performance tests of catalytic incinerators used for volatile organic compound (VOC) emissions control at industrial sites. VOC emissions are of co...

275

Volatile organic compound emissions from usaf wastewater treatment plants in ozone nonattainment areas. Master's thesis  

Microsoft Academic Search

In accordance with the 1990 Clean Air Act Amendments (CAAA), this research conducts an evaluation of the potential emission of volatile organic compounds (VOCs) from selected Air Force wastewater treatment plants. Using a conservative mass balance analysis and process specific simulation models, volatile organic emission estimates are calculated for four individual facilities--Edwards AFB, Luke AFB, McGuire AFB, and McClellan AFB--which

Ouellette

1994-01-01

276

Guideline series: Control of volatile organic compound emissions from offset lithographic printing. Draft report  

SciTech Connect

The report is a draft control techniques guideline (CTG) document for control of volatile organic compound emissions from offset lithographic printing. The document address sheet fed, non-heatset web, newspapers, and heat-set web offset lithographic printing. The principle emission sources addressed are fountain solution, cleaning solvents (blanket and roller washes) and heatset dryers. The purpose of a CTG document is to assist state and local air pollution agencies in developing regulations to limit emissions of volatile organic compounds.

NONE

1993-09-01

277

Reaction Rates of Semi-Volatile Organic Compounds with the Hydroxyl Radical  

Microsoft Academic Search

The atmosphere is the primary route of global dispersion of many semi-volatile organic compounds (SOCs), including polychlorinated biphenyls, dibenzo-p-dioxins, and dibenzofurans. While the long-distance atmospheric transport of these compounds has been well established, the importance of chemical reactions that may occur while SOCs are in the atmosphere is largely unknown. For most semi-volatile organic compounds in the vapor phase, the

Philip Neal Anderson

1995-01-01

278

Characteristics of major volatile organic hazardous air pollutants in the urban air of Kaohsiung city  

Microsoft Academic Search

The concentrations and characteristics of volatile organic hazardous air pollutants (HAPs) in the urban city of Kaohsiung\\u000a from motor vehicles and dense pollutant sources has become a national concern. To continuously monitor volatile organic HAPs,\\u000a sampling sites were selected near the four air-quality monitoring stations established by Ethe nvironmental Protection Administration\\u000a of Taiwan ROC, namely Nan-tz, Tso-ying, San-min and Hsiao-kang,

Mei-Chuan Huang; Jim Juimin Lin

2007-01-01

279

Headspace-SPME-GC-MS Identification of Volatile Organic Compounds Released from Expanded Polystyrene  

Microsoft Academic Search

A method for the identification of volatile organic compounds (VOCs) released from packaging expanded polystyrene (EPS) is presented. Headspace solid-phase microextraction (HS-SPME) with a 75-m carboxen-polydimethylsiloxan fiber was used as sample preparation technique before the determination of the volatile organic compounds by gas chromatographymass spectrometry (GC-MS). For separation of compounds, two fused silica capillary columns of different polarity (DB-5ms and

Peter Kusch; Gerd Knupp

2004-01-01

280

A two-dimensional volatility basis set - Part 2: Diagnostics of organic-aerosol evolution  

NASA Astrophysics Data System (ADS)

We discuss the use of a two-dimensional volatility-oxidation space (2-D-VBS) to describe organic-aerosol chemical evolution. The space is built around two coordinates, volatility and the degree of oxidation, both of which can be constrained observationally or specified for known molecules. Earlier work presented the thermodynamics of organics forming the foundation of this 2-D-VBS, allowing us to define the average composition (C, H, and O) of organics, including organic aerosol (OA) based on volatility and oxidation state. Here we discuss how we can analyze experimental data, using the 2-D-VBS to gain fundamental insight into organic-aerosol chemistry. We first present a well-understood "traditional" secondary organic aerosol (SOA) system - SOA from ?-pinene + ozone, and then turn to two examples of "non-traditional" SOA formation - SOA from wood smoke and dilute diesel-engine emissions. Finally, we discuss the broader implications of this analysis.

Donahue, N. M.; Kroll, J. H.; Pandis, S. N.; Robinson, A. L.

2011-09-01

281

A two-dimensional volatility basis set - Part 2: Diagnostics of organic-aerosol evolution  

NASA Astrophysics Data System (ADS)

We discuss the use of a two-dimensional volatility-oxidation space (2-D-VBS) to describe organic-aerosol chemical evolution. The space is built around two coordinates, volatility and the degree of oxidation, both of which can be constrained observationally or specified for known molecules. Earlier work presented the thermodynamics of organics forming the foundation of this 2-D-VBS, allowing us to define the average composition (C, H, and O) of organics, including organic aerosol (OA) based on volatility and oxidation state. Here we discuss how we can analyze experimental data, using the 2-D-VBS to gain fundamental insight into organic-aerosol chemistry. We first present a well-understood "traditional" secondary organic aerosol (SOA) system - SOA from ?-pinene + ozone, and then turn to two examples of "non-traditional" SOA formation - SOA from wood smoke and dilute diesel-engine emissions. Finally, we discuss the broader implications of this analysis.

Donahue, N. M.; Kroll, J. H.; Pandis, S. N.; Robinson, A. L.

2012-01-01

282

DETERMINATION OF VOLATILE ORGANICS IN INDUSTRIAL AND MUNICIPAL WASTEWATERS  

EPA Science Inventory

This report describes the systematic evaluation of a series of parameters leading to the development of a test procedure for 36 volatile priority pollutants in wastewaters. A study of the effect of pH, temperature, and residual chlorine on the aqueous stability of the compounds l...

283

40 CFR 60.722 - Standards for volatile organic compounds.  

Code of Federal Regulations, 2013 CFR

...Coating of Plastic Parts for Business Machines § 60.722 Standards for volatile...coating of plastic parts for business machines. (2) 1.5 kilograms of VOC's...coating of plastic parts for business machines. (3) 2.3 kilograms of...

2013-07-01

284

Microextraction techniques for the determination of volatile and semivolatile organic compounds from plants: A review.  

PubMed

Vegetables and fruits are necessary for human health, and traditional Chinese medicine that uses plant materials can cure diseases. Thus, understanding the composition of plant matrix has gained increased attention in recent years. Since plant matrix is very complex, the extraction, separation and quantitation of these chemicals are challenging. In this review we focus on the microextraction techniques used in the determination of volatile and semivolatile organic compounds (such as esters, alcohols, aldehydes, hydrocarbons, ketones, terpenes, sesquiterpene, phenols, acids, plant secondary metabolites and pesticides) from plants (e.g., fruits, vegetables, medicinal plants, tree leaves, etc.). These microextraction techniques include: solid phase microextraction (SPME), stir-bar sorptive extraction (SBSE), single drop microextraction (SDME), hollow fiber liquid phase microextraction (HF-LPME), dispersive liquid liquid microextraction (DLLME), and gas purge microsyringe extraction (GP-MSE). We have taken into consideration papers published from 2008 to the end of January 2013, and provided critical and interpretative review on these techniques, and formulated future trends in microextraction for the determination of volatile and semivolatile compounds from plants. PMID:24091369

Yang, Cui; Wang, Juan; Li, Donghao

2013-08-06

285

Cadaveric volatile organic compounds released by decaying pig carcasses (Sus domesticus L.) in different biotopes.  

PubMed

Forensic entomology uses pig carcasses to surrogate human decomposition and to investigate the entomofaunal colonization. Insects communicate with their environment through the use of chemical mediators, which in the case of necrophagous insects, may consist in the cadaveric volatile organic compounds (VOCs) released by the corpse under decomposition. Previous studies have focused on cadaveric VOCs released from human corpses. Nevertheless, studies on human corpses are restricted for many reasons, including ethics. Forensic entomologists use pig as animal model but very few information are available about the decompositional VOCs released by a decaying pig carcass. We here tested a passive sampling technique, the Radiello diffusive sampler, to monitor the cadaveric VOCs released by decomposing pig carcasses in three biotopes (crop field, forest, urban site). A total of 104 chemical compounds, exclusively produced by the decompositional process, were identified by thermal desorption interfaced with gas chromatography and mass spectrometry (TDS-GC-MS). Ninety, 85 and 57 cadaveric VOCs were identified on pig carcasses laying on the agricultural site, the forest biotope and in the urban site, respectively. The main cadaveric VOCs are acids, cyclic hydrocarbons, oxygenated compounds, sulfur and nitrogen compounds. A better knowledge of the smell of death and their volatile constituents may have many applications in forensic sciences. PMID:19423246

Dekeirsschieter, J; Verheggen, F J; Gohy, M; Hubrecht, F; Bourguignon, L; Lognay, G; Haubruge, E

2009-05-06

286

Contributions of individual reactive biogenic volatile organic compounds to organic nitrates above a mixed forest  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOCs) can react in the atmosphere to form organic nitrates, which serve as NOx (NO + NO2) reservoirs, impacting ozone and secondary organic aerosol production, the oxidative capacity of the atmosphere, and nitrogen availability to ecosystems. To examine the contributions of biogenic emissions and the formation and fate of organic nitrates in a forest environment, we simulated the oxidation of 57 individual BVOCs emitted from a rural mixed forest in northern Michigan. Key BVOC-oxidant reactions were identified for future laboratory and field investigations into reaction rate constants, yields, and speciation of oxidation products. Of the total simulated organic nitrates, monoterpenes contributed ~70% in the early morning at ~12 m above the forest canopy when isoprene emissions were low. In the afternoon, when vertical mixing and isoprene nitrate production were highest, the simulated contribution of isoprene-derived organic nitrates was greater than 90% at all altitudes, with the concentration of secondary isoprene nitrates increasing with altitude. Notably, reaction of isoprene with NO3 leading to isoprene nitrate formation was found to be significant (~8% of primary organic nitrate production) during the daytime, and monoterpene reactions with NO3 were simulated to comprise up to ~83% of primary organic nitrate production at night. Lastly, forest succession, wherein aspen trees are being replaced by pine and maple trees, was predicted to lead to increased afternoon concentrations of monoterpene-derived organic nitrates. This further underscores the need to understand the formation and fate of these species, which have different chemical pathways and oxidation products compared to isoprene-derived organic nitrates and can lead to secondary organic aerosol formation.

Pratt, K. A.; Mielke, L. H.; Shepson, P. B.; Bryan, A. M.; Steiner, A. L.; Ortega, J.; Daly, R.; Helmig, D.; Vogel, C. S.; Griffith, S.; Dusanter, S.; Stevens, P. S.; Alaghmand, M.

2012-11-01

287

Odors and volatile organic compounds released from ventilation filters  

NASA Astrophysics Data System (ADS)

Used supply air filters were studied by sensory and chemical methods. In addition, filter dust was examined by thermodesorption/cold trap (TCT) and headspace (HS) devices connected to a GC-MS. The prefilter was the main odor source in the ventilation unit, but when humidifier was turned on odor was released mainly from the fine filter. However, the effect of the relative humidity (RH) was only temporary. At the same time, there was an increase in the concentration of aldehydes after the filters. Aldehydes, carboxylic acids, and nitrogen-containing organic compounds were the main emission products in the thermodesorption analyses of the filter dust. Many of these compounds have low odor threshold values and, therefore, contribute to the odor released from the filters. Especially, the role of aldehydes seems to be important in the odor formation.

Hyttinen, Marko; Pasanen, Pertti; Bjrkroth, Marko; Kalliokoski, Pentti

288

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

PubMed

Results are presented that were obtained on the geographic traceability of the white truffle Tuber magnatum Pico. Solid-phase microextraction coupled to gas chromatography/mass spectrometry (SPME-GC/MS) was employed to characterize the volatile profile of T. magnatum white truffle produced in seven geographical areas of Italy. The main components of the volatile fraction were identified using SPME-GC/MS. Significant differences in the proportion of volatile constituents from truffles of different geographical areas were detected. The results suggest that, besides genetic factors, environmental conditions influence the formation of volatile organic compounds. The mass spectra of the volatile fraction of the samples were used as fingerprints to characterize the geographical origin. Next, stepwise factorial discriminant analysis afforded a limited number of characteristic fragment ions that allowed a geographical classification of the truffles studied. PMID:18798200

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

2008-10-01

289

Determination of Acid Volatile Sulfide and Selected Simultaneously Extractable Metals in Sediment.  

National Technical Information Service (NTIS)

The method describes procedures for the determination of acid volatile sulfide (AVS) and for selected metals that are solubilized during the acidification step (simultaneously extracted metal, SEM). As a precipitant of toxic heavy metals, sulfide is impor...

H. E. Allen G. Fu W. Boothman D. M. DiToro J. D. Mahony

1991-01-01

290

Acid-Volatile Sulfide as a Factor Mediating Cadmium and Nickel Bioavailability in Contaminated Sediments.  

National Technical Information Service (NTIS)

The authors investigated the influence of sulfide, measured as acid-volatile sulfide (AVS), on the bioavailability of cadmium and nickel in sediments. Seventeen samples from an estuarine system heavily contaminated with cadmium and nickel were analyzed fo...

G. T. Ankley G. L. Phipps E. L. Leonard D. A. Benoit V. R. Mattson

1991-01-01

291

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

NASA Astrophysics Data System (ADS)

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 storage of silage. Aldehydes may also be produced aerobically by spoilage microorganisms through the oxidation of alcohols. Abiotic reactions may be important for production of methanol and esters. Although silage additives appear to affect VOC production in individual studies, bacterial inoculants have not shown a consistent effect on ethanol, and effects on other VOCs have not been studied. Production of acetic acid is understood, and production could be minimized, but a decrease could lead to an increase in other, more volatile and more reactive, VOCs. Chemical additives designed for controlling yeasts and undesirable bacteria show promise for reducing ethanol production in corn silage.More work is needed to understand silage VOC production and emission from silage, including: additional measurements of VOC concentrations or production in silage of all types, and an exploration of the causes of variability; accurate on-farm measurements of VOC emission, including an assessment of the importance of individual ensiling stages and practices that could reduce emission of existing VOCs; and work on understanding the sources of silage VOCs and possible approaches for reducing production.

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

292

Adsorption of volatile organic compounds in porous metal-organic frameworks functionalized by polyoxometalates  

NASA Astrophysics Data System (ADS)

The functionalization of porous metal-organic frameworks (Cu3(BTC)2) was achieved by incorporating Keggin-type polyoxometalates (POMs), and further optimized via alkali metal ion-exchange. In addition to thermal gravimetric analysis, IR, single-crystal X-ray diffraction, and powder X-ray diffraction, the adsorption properties were characterized by N2 and volatile organic compounds (VOCs) adsorption measurements, including short-chain alcohols (C<4), cyclohexane, benzene, and toluene. The adsorption enthalpies estimated by the modified Clausius-Clapeyron equation provided insight into the impact of POMs and alkali metal cations on the adsorption of VOCs. The introduction of POMs not only improved the stability, but also brought the increase of adsorption capacity by strengthening the interaction with gas molecules. Furthermore, the exchanged alkali metal cations acted as active sites to interact with adsorbates and enhanced the adsorption of VOCs.

Ma, Feng-Ji; Liu, Shu-Xia; Liang, Da-Dong; Ren, Guo-Jian; Wei, Feng; Chen, Ya-Guang; Su, Zhong-Min

2011-11-01

293

Branched-chain and aromatic amino acid catabolism into aroma volatiles in Cucumis melo L. fruit  

Technology Transfer Automated Retrieval System (TEKTRAN)

The unique aroma of melons (Cucumis melo L., Cucurbitaceae) is composed of many volatile compounds biosynthetically derived from fatty-acids, carotenoids, amino-acids as well as terpenes. Incubation of melon fruit cubes with amino- and a-keto acids led to the enhanced formation of aroma compounds be...

294

Organic non-volatile memories from ferroelectric phase-separated blends  

Microsoft Academic Search

New non-volatile memories are being investigated to keep up with the organic-electronics road map. Ferroelectric polarization is an attractive physical property as the mechanism for non-volatile switching, because the two polarizations can be used as two binary levels. However, in ferroelectric capacitors the read-out of the polarization charge is destructive. The functionality of the targeted memory should be based on

Kamal Asadi; Dago M. de Leeuw; Bert de Boer; Paul W. M. Blom

2008-01-01

295

Modeling organic aerosols in a megacity: potential contribution of semi-volatile and intermediate volatility primary organic compounds to secondary organic aerosol formation  

NASA Astrophysics Data System (ADS)

It has been established that observed local and regional levels of secondary organic aerosols (SOA) in polluted areas cannot be explained by the oxidation and partitioning of anthropogenic and biogenic VOC precursors, at least using current mechanisms and parameterizations. In this study, the 3-D regional air quality model CHIMERE is applied to estimate the potential contribution to SOA formation of recently identified semi-volatile and intermediate volatility organic precursors (S/IVOC) in and around Mexico City for the MILAGRO field experiment during March 2006. The model has been updated to include explicitly the volatility distribution of primary organic aerosols (POA), their gas-particle partitioning and the gas-phase oxidation of the vapors. Two recently proposed parameterizations, those of Robinson et al. (2007) ("ROB") and Grieshop et al. (2009) ("GRI") are compared and evaluated against surface and aircraft measurements. The 3-D model results are assessed by comparing with the concentrations of OA components from Positive Matrix Factorization of Aerosol Mass Spectrometer (AMS) data, and for the first time also with oxygen-to-carbon ratios derived from high-resolution AMS measurements. The results show a substantial enhancement in predicted SOA concentrations (2-4 times) with respect to the previously published base case without S/IVOCs (Hodzic et al., 2009), both within and downwind of the city leading to much reduced discrepancies with the total OA measurements. Model improvements in OA predictions are associated with the better-captured SOA magnitude and diurnal variability. The predicted production from anthropogenic and biomass burning S/IVOC represents 40-60% of the total measured SOA at the surface during the day and is somewhat larger than that from commonly measured aromatic VOCs, especially at the T1 site at the edge of the city. The SOA production from the continued multi-generation S/IVOC oxidation products continues actively downwind. Similar to aircraft observations, the predicted OA/?CO ratio for the ROB case increases from 20-30 ?g sm-3 ppm-1 up to 60-70 ?g sm-3 ppm-1 between a fresh and 1-day aged air mass, while the GRI case produces a 30% higher OA growth than observed. The predicted average O/C ratio of total OA for the ROB case is 0.16 at T0, substantially below observed value of 0.5. A much better agreement for O/C ratios and temporal variability (R2=0.63) is achieved with the updated GRI treatment. Both treatments show a deficiency in regard to POA ageing with a tendency to over-evaporate POA upon dilution of the urban plume suggesting that atmospheric HOA may be less volatile than assumed in these parameterizations. This study highlights the important potential role of S/IVOC chemistry in the SOA budget in this region, and highlights the need for further improvements in available parameterizations. The agreement observed in this study is not sufficient evidence to conclude that S/IVOC are the major missing SOA source in megacity environments. The model is still very underconstrained, and other possible pathways such as formation from very volatile species like glyoxal may explain some of the mass and especially increase the O/C ratio.

Hodzic, A.; Jimenez, J. L.; Madronich, S.; Canagaratna, M. R.; Decarlo, P. F.; Kleinman, L.; Fast, J.

2010-06-01

296

Modeling organic aerosols in a megacity: potential contribution of semi-volatile and intermediate volatility primary organic compounds to secondary organic aerosol formation  

SciTech Connect

It has been established that observed local and regional levels of secondary organic aerosols (SOA) in polluted areas cannot be explained by the oxidation and partitioning of traditional anthropogenic and biogenic VOC precursors. In this study, the 3D regional air quality model CHIMERE is applied to quantify the contribution to SOA formation of recently identified semi-volatile and intermediate volatility organic vapors (S/IVOC) in and around Mexico City for the MILAGRO field experiment during March 2006. The model has been updated to explicitly include the volatility distribution of primary organic aerosols (POA), their gas-particle partitioning and the gas-phase oxidation of the vapors. Two recently proposed parameterizations, those of Robinson et al. (2007) ("ROB") and Grieshop et al. (2009) ("GRI") are compared and evaluated against surface and aircraft measurements. For the first time, 3D model results are assessed by comparing with the concentrations of OA components from Positive Matrix Factorization of Aerosol Mass Spectrometer (AMS) data, but also against and oxygen-to-carbon ratios derived from high-resolution AMS measurements. The results show a substantial enhancement in predicted SOA concentrations (3-6 times) with respect to the previously published base case without S/IVOCs (Hodzic et al., 2009), both within and downwind of the city leading to much reduced discrepancies with the total OA measurements. The predicted anthropogenic POA levels are found to agree within 20% with the observed HOA concentrations for both the ROB and GRI simulations, consistent with the interpretation of the emissions inventory by previous studies. The impact of biomass burning POA within the city is underestimated in comparison to the AMS BBOA, presumably due to insufficient nighttime smoldering emissions. Model improvements in OA predictions are associated with the better-captured SOA magnitude and diurnal variability. The production from anthropogenic and biomass burning S/IVOC represents 40-60% of the total SOA at the surface during the day and is somewhat larger than that from aromatics, especially at the T1 site at the edge of the city. The downwind SOA production from the continued multi-generation S/IVOC oxidation products actively continues. Similar to aircraft observations, the predicted OA/DCO ratio for the ROB case increases from 20-30 mg sm-3 ppm-1 up to 60-70 mg sm-3 ppm-1 between a fresh and 1-day aged air mass, while the GRI case produces a 30-40% higher OA growth than observed. The predicted average O/C ratio of total OA for the ROB case is 0.16 at T0, substantially below observed value of 0.5. A much better agreement for O/C ratios and temporal variability (R2=0.63) is achieved with the updated GRI treatment. Both treatments show a deficiency in regard to POA evolution with a tendency to over-evaporate POA upon dilution of the urban plume suggesting that atmospheric HOA may be less volatile than assumed in these parameterizations. This study highlights the very important potential role of S/IVOC chemistry in the SOA budget in this region, and highlights the need for improvements in current parameterizations. We note that other proposed pathways of SOA formation such as formation from very volatile species like glyoxal were not included in our simulations, which can also contribute SOA mass and especially increase the O/C ratio.

Hodzic, Alma; Jimenez, Jose L.; Madronich, Sasha; Canagaratna, M. R.; DeCarlo, Peter F.; Kleinman, Lawrence I.; Fast, Jerome D.

2010-06-21

297

Abundances and flux estimates of volatile organic compounds from a dairy cowshed in Germany.  

PubMed

Animal husbandry and manure treatment have been specifically documented as significant sources of methane, ammonia, nitrous oxide, and particulate matter. Although volatile organic compounds (VOCs) are also produced, much less information exists concerning their impact. We report on chemical ionization mass spectrometry and photo-acoustic spectroscopy measurements of mixing ratios of VOCs over a 2-wk measurement period in a large cowshed at the Federal Agricultural Research Centre (FAL) in Mariensee, Germany. The high time resolution of these measurements enables insight into the sources of the emissions in a typical livestock management setting. During feeding hours and solid manure removal, large mixing ratio spikes of several VOCs were observed and correlated with simultaneous methane, carbon dioxide, and ammonia level enhancements. The subsequent decay of cowshed concentration due to passive cowshed ventilation was used to model emission rates, which were dominated by ethanol and acetic acid, followed by methanol. Correlations of VOC mixing ratios with methane or ammonia were also used to calculate cowshed emission factors and to estimate potential nationwide VOC emissions from dairy cows. The results ranged from around 0.1 Gg carbon per year (1 Gg = 10(9) g) for nonanal and dimethylsulfide, several Gg carbon per year for volatile fatty acids and methanol, to over 10 Gg carbon per year of emitted ethanol. While some estimates were not consistent between the two extrapolation methods, the results indicate that animal husbandry VOC emissions are dominated by oxygenated compounds and may be a nationally but not globally significant emission to the atmosphere. PMID:18396542

Ngwabie, Ngwa Martin; Schade, Gunnar W; Custer, Thomas G; Linke, Stefan; Hinz, Torsten

298

Volatile Organic Compounds Obtained by in Vitro Callus Cultivation of Plectranthus ornatus Codd. (Lamiaceae).  

PubMed

Plectranthus spp (Lamiaceae) are plants of economic importance because they are sources of aromatic essential oils and are also cultivated and several species of this genus are used as folk medicines. This paper describes the effects of different concentrations of the 2,4-dichlorophenoxyacetic acid (2,4-D) and 1-naphthaleneacetic acid (NAA) on the induction of callus from nodal segments of Plectranthus ornatus Codd and in the production of volatile organic compounds (monoterpenes and sesquiterpenes). The 20 and 40 day calli were subjected to solid phase micro extraction (HS-SPME) and submitted to GCMS analysis. Variations in VOCs between the samples were observed and, a direct relationship was observed between of the major constituent detected (?-terpinyl acetate) and the monoterpenes ?-thujene, ?-pinene, ?-pinene, camphene, sabinene and ?-limonene that were present in the volatile fractions. Besides ?-terpinyl acetate, isobornyl acetate and ?-limonene were also major constituents. Variations were observed in VOCs in the analyzed periods. The best cultivation media for the production of VOCs was found to be MS0 (control). Moderate success was achieved by treatment with 2.68 M and 5:37 M NAA (Group 2). With 2,4-D (9.0 M), only the presence of ?-terpinyl acetate and isocumene were detected and, with 2.26 M of 2,4-D was produced mainly ?-terpinyl acetate, ?-thujene and ?-caryophyllene (16.2%). The VOC profiles present in P. ornatus were interpreted using PCA and HCA. The results permitted us to determine the best cultivation media for VOC production and, the PCA and HCA analysis allowed us to recognize four groups among the different treatments from the compounds identified in this set of treatments. PMID:24064448

Passinho-Soares, Helna C; Meira, Paloma R; David, Juceni P; Mesquita, Paulo R R; Vale, Ademir E do; de M Rodrigues, Frederico; de P Pereira, Pedro A; de Santana, Jos Raniere F; de Oliveira, Fabio S; de Andrade, Jailson B; David, Jorge M

2013-08-26

299

Volatile buffers can override the "pH memory" of subtilisin catalysis in organic media.  

PubMed

The protonation state and activity of enzymes in low-water media are affected by the aqueous pH before drying ("pH memory"). However, both protonation and activity will change if buffer ions can be removed as volatile or organic-extractable weak acids or bases. With NH4OOCH buffers, in which both ions can be removed, pH memory disappears completely for subtilisin-catalyzed transesterification in hexane. Only weak pH memory is found with buffers having one volatile component, NH4-phosphate and NaOOCH. The changes in ionization state result from proton exchanges like Protein-COO-NH4+ --> Protein-COOH + NH3 (g) and Protein-NH3+HCOO- --> Protein-NH2 + HOOCH (g). An equivalent, complementary picture is that net charges on the protein and buffer ions must remain equal and opposite. With NaOOCH buffers, loss of some HCOO- ions gives a more negative net charge on the protein, balanced by the excess Na+. With NH4-phosphate buffers, loss of NH3 gives protein with a more positive net charge. The resulting catalytic activities were high and low, respectively, similar to those after drying from Na-phosphate buffers of optimal (8.5) and acid pH. All of the above effects have been demonstrated for both covalently immobilized subtilisin and the lyophilized free enzyme. Subtilisin lyophilized from NH4OOCH buffers gave pH approximately 4 after redissolution in water, probably because removal of HCOO- counterions remains incomplete. The resulting catalytic activity was low. The effects are discussed in relation to the possible locations, in low-dielectric media, of the positive charge that balances the net negative catalytic triad in active subtilisin. PMID:9990001

Zacharis, E; Halling, P J; Rees, D G

1999-02-16

300

Effect of source on net portal flux of glucose, lactate, volatile fatty acids and amino acids in the pig  

Microsoft Academic Search

The ileal digestibilities of maize starch and native pea starch do not differ. However maize starch is digested faster than pea starch and the ileal amino acid digestibility of a diet containing pea starch is lower. In the present study, the net portal fluxes of glucose, lactate, volatile fatty acids (VFA) and amino acids were measured for diets including 650

J. Van Der Meulen; J. G. M. Bakker; B. Smits; H. De Visser

1997-01-01

301

Henry`s law constant for selected volatile organic compounds in high-boiling oils  

SciTech Connect

Absorption systems are often used to remove and recover organic vapors from process air/gas streams. A high boiling and inert liquid like silicone oil is an excellent absorbent for volatile organic compounds in air. Henry`s law constants of four different volatile organic compounds, namely, acetone, methanol, methylene chloride, and toluene between air and high-boiling oils were determined experimentally by the headspace-GC technique over a temperature range. The Henry`s law constants were fitted as a function of temperature to an equation.

Poddar, T.K.; Sirkar, K.K. [New Jersey Inst. of Tech., Newark, NJ (United States). Dept. of Chemical Engineering, Chemistry and Environmental Science

1996-11-01

302

A Novel Method for Analyzing Microbially Affiliated Volatile Organic Compounds in Soil Environments  

NASA Astrophysics Data System (ADS)

A concerted, international effort by citizens, governments, industries and educational systems is necessary to address the myriad environmental issues that face us today. The authors of this paper concentrate on soil environments and, specifically, the methods currently used to characterize them. The ability to efficiently and effectively monitor and characterize various soils is desired, allows for the study, supervision, and protection of natural and cultivated ecosystems, and may assist stakeholders in meeting governmentally-imposed environmental standards. This research addresses soil characterization by a comparison of four methods that emphasize a combination of microbial community and metabolic measures: BIOLOG, fatty acid methyl-ester analysis (FAME), descriptive physical and chemical analysis (moisture content, pH, carbon content, nutrient content, and grain size), and the novel soil-microbe volatile organic compound analysis (SMVOC) presented in this work. In order to achieve the method comparison, soils were collected from three climatic regions (Bahamas, Michigan, and Mississippi), with three samples taken from niche ecosystems found at each climatic region (a total of nine sites). Of interest to the authors is whether or not an investigation of microbial communities and the volatile organic compounds (VOCs) produced by microbial communities from nine separate soil ecosystems provides useful information about soil dynamics. In essence, is analysis of soil-derived VOCs using gas chromatography-mass spectrometry (GC-MS) an effective method for characterizing microbial communities and their metabolic activity of soils rapidly and accurately compared with the other three traditional characterization methods? Preliminary results suggest that VOCs in each of these locales differ with changes in soil types, soil moisture, and bacterial community. Each niche site shows distinct patterns in both VOCs and BIOLOG readings. Results will be presented to show the efficacy of the SMVOC approach and the statistical alignment of the VOC and community measures.

Ruhs, C. V.; McNeal, K. S.

2010-12-01

303

The effect of concentration polarization on the separation of volatile organic compounds from water by pervaporation  

Microsoft Academic Search

Concentration polarization dominates the separation of dissolved volatile organic compounds from water by pervaporation. This is particularly true with hydrophobic organics, such as toluene and trichloroethylene, for which concentration polarization is severe even in highly turbulent membrane modules. With these compounds, measured separation factors can be 10 to 20% of the intrinsic separation factors in the absence of concentration polarization.

R. W. Baker; J. G. Wijmans; A. L. Athayde; R. Daniels; J. H. Ly; M. Le

1997-01-01

304

Determination of Volatile Organic Profiles and Photochemical Potentials from Chemical Manufacture Process Vents  

Microsoft Academic Search

The main objective of this study was to monitor the volatile organic compounds (VOCs) in the stack gas released from organic chemical industrial plants to determine emission factors. Samples from 52 stacks, with or without air pollution control devices (APCDs), from seven industrial processes were taken and VOCs measured using U.S. Environmental Protection Agency (EPA) Method 18. These 7 processes,

Yi-Chyun Hsu; Shan-Kun Chen; Jiun-Horng Tsai; Hung-Lung Chiang; Eric Fujita; Barbara Zielinska; David Campbell; W. Arnott; Judith Chow; Peter Gabele; William Crews; Richard Snow; Nigel Clark; W. Wayne; Douglas Lawson; Steven Brown; Anna Frankel; Sean Raffuse; Paul Roberts; Hilary Hafner; Darcy Anderson; Bart Eklund; Michelle Simon; Shekhar Regmi; Maneerat Ongwandee; Glenn Morrison; Mark Fitch; Rao Surampalli

2007-01-01

305

Microbial community related to volatile organic compound (VOC) emission in household biowaste  

Microsoft Academic Search

Summary Malodorous emissions and potentially pathogenic microorganisms which develop during domestic organic waste collection are not only a nuisance but may also pose health risks. The aim of the present study was to determine whether the presence of spe- cific microorganisms in biowastes is directly related to the composition of the emitted volatile organic compounds (VOCs). The succession of microbial

Sabine Mayrhofer; Tomas Mikoviny; Sebastian Waldhuber; Andreas O. Wagner; Gerd Innerebner; Ingrid H. Franke-Whittle; Tilman D. Mrk; Armin Hansel; Heribert Insam

2006-01-01

306

Evaluation of the walkthrough survey method for detection of volatile organic compound leaks. Final report  

Microsoft Academic Search

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 of their sampling program, several 'walkthrough surveys,' also called 'unit area surveys,' were conducted. The assistance of EPA's Industrial Environmental

R. C. Weber; K. Mims

1981-01-01

307

LABORATORY AND FIELD EVALUATION OF THE SEMI-VOST (SEMI-VOLATILE ORGANIC SAMPLING TRAIN) METHOD  

EPA Science Inventory

Laboratory studies and a second field evaluation have been completed to assess the performance of the Semi-Volatile Organic Sampling Train (Semi-VOST) method for measuring concentrations of principal organic hazardous constituents (POHCs) with boiling points greater than 100 deg ...

308

Membrane systems offer a new way to recover volatile organic air pollutants  

Microsoft Academic Search

Volatile organic compounds (VOCs) and other organic compounds are the most common pollutants emitted from chemical processes. Meeting new regulations will require a range of solutions, from complete elimination of the pollution source to more conventional end-of-pipe treatment. An increasingly common solution is installing equipment that recovers and recycles raw materials and byproducts within the process. Innovative alternatives have been

V. Simmons; J. Kaschemekat; M. L. Jacobs; D. D. Dortmundt

1994-01-01

309

Evolution and Kinetics of Volatile Organic Compounds Generated during Low-Temperature Polymer Degradation  

Microsoft Academic Search

A method using direct flame ionization detector (FID) measurement was developed to study total volatile organic compound (VOC) emissions during thermal degradation of polymers. This method was used to estimate organic emissions from different polymers, such as low-density polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and commingled postconsumer streams, such as recycled carpet residue and auto shredder residue (ASR). The

Qin Xiang; Somenath Mitra; Marino Xanthos; Subir K. Dey

2002-01-01

310

Plant Volatiles-based Insect Pest Management in Organic Farming  

Microsoft Academic Search

Organic agriculture is increasing in popularity worldwide due to the rapidly growing market for organic products. In organic production, insects present a major pest challenge that negatively impacts crop health and yield. To successfully manage an organic farmland, an effective insect pest management program is key. In this review, we first describe the approaches currently used for pest management in

Gitika Shrivastava; Mary Rogers; Annette Wszelaki; Dilip R. Panthee; Feng Chen

2010-01-01

311

Gas partitioning of dissolved volatile organic compounds in the vadose zone: Principles, temperature effects and literature review  

Microsoft Academic Search

Enthalpy and entropy of volatilization from dilute aqueous solutions for 26 volatile organic compounds (VOCs) have been determined using Henry`s Law values reported in published literature. Based on the linearity of van`t Hoff plots, for the temperature ranges common in soils, the differences in heat capacities of volatilization for reactants and products are very small for the VOCs studied. When

John W. Washington

1996-01-01

312

Ion-trap detection of volatile organic compounds in alveolar breath  

SciTech Connect

We describe a method for the collection and microanalysis of the volatile organic compounds in human breath. A transportable apparatus supplies subjects with purified air and samples their alveolar breath; the volatile organic compounds are captured in an adsorptive trap containing activated carbon and molecular sieve. The sample is thermally desorbed from the trap in an automated microprocessor-controlled device, concentrated by two-stage cryofocusing, and assayed by gas chromatography with ion-trap detection. Compounds are identified by reference to a computer-based library of mass spectra with subtraction of the background components present in the inspired air. We used this device to study 10 normal subjects and determined the relative abundance of the volatile organic compounds in their alveolar breath. The breath-collecting apparatus was convenient to operate and was well tolerated by human volunteers.

Phillips, M.; Greenberg, J. (Department of Medicine, St. Vincent's Medical Center of Richmond, Staten Island, NY (United States))

1992-01-01

313

HS-SPME/GC-MS analysis of volatile and semi-volatile organic compounds emitted from municipal sewage sludge.  

PubMed

The aim of the research involved identification and semi-quantitative determination of unknown volatile and semi-volatile organic compounds emitted to air by sewage sludge formed in the process of municipal wastewater treatment in a sewage treatment plant. Samples taken directly after completion of the technological process as well as the sludge stored on the premise of the sewage treatment plant were analyzed. A simple method using off-line headspace solid-phase microextraction combined with gas chromatography-mass spectrometry has been proposed for extraction and detection of organic pollutants. For reliable identification of compounds, combination of two independent parameters: mass spectra and linear temperature programmed retention indices were employed. Over 170 compounds of different structure were identified including aliphatic and aromatic hydrocarbons, alcohols, esters, carbonyls, as well as sulfur, nitrogen, and chlorine containing compounds. The prevailing substances included: ethyl ether, n-hexane, p-xylene, o-xylene, mesitylene, m-ethylbenzene, limonene, n-decane, n-undecane, and n-dodecane. A few compounds such as methanetiol, dimethyl polisulfide, octaatomic sulfur, phthalic anhydride, and indoles were identified in the sludge for the first time. PMID:21688031

Kotowska, Urszula; ?alikowski, Maciej; Isidorov, Valery A

2011-06-18

314

A Standardized Sampling Procedure for the Determination of Volatile Organic Compounds (VOC) Determined in Snow Samples  

NASA Astrophysics Data System (ADS)

Snow samples were collected from different semi-remote and urban environments using a standardized sampling procedure in order to minimize sampling errors. Samples were collected in pre-cleaned amber glass and sterile HDPE containers. Glass bottles and all non-sterilized equipment were washed with low nutrient detergent, acid washed and rinsed with ultra-pure water. Samples were collected using pre-sterilized or acid-washed sampling tools and blanks, consisting of ultra-pure water, which were treated identically to the collected samples in to monitor contamination from sampling equipment and the different types of containers. Analysis for VOC was carried out with a previously described, but modified solid phase micro-extraction (SPME) pre-concentration method and determination of compounds using gas-chromatography with mass spectrometric detection (GC-MS) (1). Low concentrations required the use of larger sample volumes and splitless injection mode. Samples analyzed were collected in and around Montreal, Quebec (45.28 N/73.45 W) at Mont-Saint Hilaire (altitude: 415 m a.s.l.), Downtown Montreal and Parc Tremblant. We will present and compare results from all sites, and the implication for atmospheric processes will be discussed. References (1) Kos G, Ariya PA (2004), Determination of Volatile Organic Compounds in Snow Using Solid Phase Micro Extraction, Eos Trans. AGU, 85 (47), Fall Meet. Suppl., Abstract A11B-53

Kos, G.; Ariya, P. A.

2005-12-01

315

Analysis of volatile fatty acids in wastewater collected from a pig farm by a solid phase microextraction method.  

PubMed

The main purpose of this study is to develop a reliable Solid Phase Microextraction (SPME) method for monitoring the concentration of volatile fatty acid (VFA) in the wastewater collected from pig farms. Ten volatile fatty acid species were spiked in 2 ml of swine wastewater and extracted with a carbowax coated extraction fiber to evaluate the accuracy and precision of the method. The fiber was introduced into a gas chromatography system by thermal desorption and detected by a mass spectrometer detector. The estimated method detection limits ranged from 11.5 mM/L for formic acid to 0.03 mM/L for heptanoic acid. The method is more sensitive than the sample direct injection method. The percentage recovery of analytes ranged from 77.3 for propanoic acid to 114.1 for formic acid at the spike level of 19.09 mM/L. The compound absorption rate varied significantly with the fiber absorption time for n-Valeric, isocaproic, n-caproic and heptanoic acids. An SPME method with twenty minutes fiber absorption and three minutes thermal desorption was tested in this study and resulted in good reproducibility for analyzing VFAs in swine wastewater. The method may be applied for scanning a wide spectrum of polar organic compounds in environmental samples. PMID:10903114

Yo, S P

1999-02-01

316

Volatile fatty acids production from food wastes and its application to biological nutrient removal  

Microsoft Academic Search

Korean food wastes were anaerobically digested to produce volatile fatty acids (VFA) that can be used as a carbon source in biological nutrient removal in a sequential batch reactor (SBR). Acetate, propionate and butyrate were produced at a yield of 379-400 g VFA\\/kg VS0 (initial volatile solids). The ratio of SCOD (Soluble Chemical Oxygen Demand) of VFA to ammonia nitrogen

S.-J. Lim; D. W. Choi; W. G. Lee; S. Kwon; H. N. Chang

2000-01-01

317

Electrical conductivity of mixed structures based on conjugated organic materials and metals oxides upon adsorption of volatile organic compounds  

NASA Astrophysics Data System (ADS)

This paper reports on the results of investigations of the electrophysical characteristics of films based on conjugated organic molecules of copper phthalocyanine (CuPc) and the perylene derivative 3,4,9,10-perylenetetracarboxylic acid dianhydride mixed with TiO2 microparticles and SnO2 nanoparticles. The electrical resistivity of the mixed films under investigation lies in the range from 5 108 to 5 109 GQ cm. The influence of adsorption on the surface of the films on the electrical conductivity is studied using vapors of water and volatile organic compounds, such as ethanol, ammonia, toluene, and acetone, at pressures in the range from 10-1 to 10 Pa. The adsorption of acetone and toluene vapors does not lead to considerable changes in the electrical conductivity of the films, whereas the exposure to vapors of water, ethanol, and ammonia results in a reversible multiple increase in the electrical conductivity of the studied films. In the case of mixed CuPc/TiO2 films, the electrical conductivity observed upon adsorption of ammonia vapors on the film surface exceeds the initial conductivity by a factor of approximately 2500. The mechanisms of the observed changes in the electrical conductivity are discussed with allowance made for the increase in the electron density of the films due to the electron exchange with adsorbed molecules of reducing gases.

Komolov, A. S.; Gerasimova, N. B.; Lazneva, . F.; Akhremchik, S. N.

2009-08-01

318

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

PubMed

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

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

2012-06-08

319

Determination of volatile organic profiles and photochemical potentials from chemical manufacture process vents.  

PubMed

The main objective of this study was to monitor the volatile organic compounds (VOCs) in the stack gas released from organic chemical industrial plants to determine emission factors. Samples from 52 stacks, with or without air pollution control devices (APCDs), from seven industrial processes were taken and VOCs measured using U.S. Environmental Protection Agency (EPA) Method 18. These 7 processes, including 26 plants, were the manufacturers of acrylonitrile-butadiene-styrene (ABS), polyvinyl chloride (PVC), polystyrene (PS), acrylic resin (ACR), vinyl chloride (VC), para-terephthalic acid (PTA), and synthetic fiber (SYF). The results clearly indicate significant variations of emission factors among the various industrial processes, particularly emission factors for those without APCDs. As expected, those with APCDs yield much less emission factors. Regardless of those with or without APCDs, the order of manufacturing processes with regard to VOC emission factors is SYF > ABS > PS >ACR > PTA > PVC > VC. The emission factors for some processes also differ from those in EPA-42 data file. The VOC profiles further indicate that some VOCs are not listed in the U.S. VOC/Particulate Matter Speciation Data System (SPECIATE). The potential O3 formation is determined from the total amount of VOC emitted for each of seven processes. The resultant O3 yield varied from 0.22 (ACR) to 2.33 g O3 g(-1) VOC (PTA). The significance of this O3 yield is discussed. PMID:17608005

Hsu, Yi-Chyun; Chen, Shan-Kun; Tsai, Jiun-Horng; Chiang, Hung-Lung

2007-06-01

320

Volatile acetic acid and formaldehyde emission from plywood treated with boron compound  

Microsoft Academic Search

The effects of plywood on formaldehyde and volatile acetic acid emissions treated with borax and boric acid were investigated. The treated plywood samples were manufactured by using two different methods; each veneer was first impregnated by a dipping method before the first group of plywood was manufactured. The second group of plywood panels was produced by adding preservatives (borax, boric

S. Colak; G. Colakoglu

2004-01-01

321

Alcohol production through volatile fatty acids reduction with hydrogen as electron donor by mixed cultures  

Microsoft Academic Search

In this research we demonstrated a new method to produce alcohols. It was experimentally feasible to produce ethanol, propanol and butanol from solely volatile fatty acids (VFAs) with hydrogen as electron donor. In batch tests, VFAs such as acetic, propionic and butyric acids were reduced by mixed microbial cultures with a headspace of 1.5bar of hydrogen. Observed alcohol concentrations were

Kirsten J. J. Steinbusch; Hubertus V. M. Hamelers; Cees J. N. Buisman

2008-01-01

322

A Simplified Extraction-Distillation Method for the Determination of the Volatile Fatty Acids of Cheese  

Microsoft Academic Search

A simple method for determining the volatile fatty acid content of cheese would be a valuable tool for the dairy chemist concerned with the ripening of cheese. Hiscox, Harrison, and Wolf (4, 5, 6) discussed this problem and proposed a method based on water extraction of the fatty acids from the cheese, and ether extraction of the fat and fat-soluble

K. L. Smiley; F. V. Kosikowsky; A. C. Dahlberg

1946-01-01

323

Analysis of volatile organic compounds of Fuji apples following electron beam irradiation and storage  

NASA Astrophysics Data System (ADS)

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.

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

2012-08-01

324

Gas-liquid chromatographic analysis of synovial fluid: volatile short-chain fatty acids in septic arthritis  

Microsoft Academic Search

Volatile short-chain fatty acids (SCFA) in synovial fluid from 80 patients were quantified by gas-liquid chromatography (GLC). Characteristic patterns of volatile SCFA could not be associated with septic, nonseptic inflammatory, or noninflammatory groups. Mean concentrations of pentanoic and hexanoic acids were similar in all groups studied. In the septic arthritis group 3 of 4 patients with acetic acid and of

D G Borenstein; C A Gibbs; R P Jacobs

1983-01-01

325

Secondary organic aerosol formation from intermediate-volatility organic compounds: cyclic, linear, and branched alkanes.  

PubMed

Intermediate volatility organic compounds (IVOCs) are an important class of secondary organic aerosol (SOA) precursors that have not been traditionally included in chemical transport models. A challenge is that the vast majority of IVOCs cannot be speciated using traditional gas chromatography-based techniques; instead they are classified as an unresolved complex mixture (UCM) that is presumably made up of a complex mixture of branched and cyclic alkanes. To better understand SOA formation from IVOCs, a series of smog chamber experiments was conducted with different alkanes, including cyclic, branched, and linear compounds. The experiments focused on freshly formed SOA from hydroxyl (OH) radical-initiated reactions under high-NO(x) conditions at typical atmospheric organic aerosol concentrations (C(OA)). SOA yields from cyclic alkanes were comparable to yields from linear alkanes three to four carbons larger in size. For alkanes with equivalent carbon numbers, branched alkanes had the lowest SOA mass yields, ranging between 0.05 and 0.08 at a C(OA) of 15 ?g m(-3). The SOA yield of branched alkanes also depends on the methyl branch position on the carbon backbone. High-resolution aerosol mass spectrometer data indicate that the SOA oxygen-to-carbon ratios were largely controlled by the carbon number of the precursor compound. Depending on the precursor size, the mass spectrum of SOA produced from IVOCs is similar to the semivolatile-oxygenated and hydrocarbon-like organic aerosol factors derived from ambient data. Using the new yield data, we estimated SOA formation potential from diesel exhaust and predict the contribution from UCM vapors to be nearly four times larger than the contribution from single-ring aromatics and comparable to that of polycyclic aromatic hydrocarbons after several hours of oxidation at typical atmospheric conditions. Therefore, SOA from IVOCs may be an important contributor to urban OA and should be included in SOA models; the yield data presented in this study are suitable for such use. PMID:22823284

Tkacik, Daniel S; Presto, Albert A; Donahue, Neil M; Robinson, Allen L

2012-08-09

326

Chemical aging of organic aerosols: Evidence of changing hygroscopicity and volatility  

NASA Astrophysics Data System (ADS)

Organic aerosols constitute a large fraction of the tropospheric aerosol budget. The composition and size of aerosol is important with respect to its effect on radiative forcing and impacts upon human health. During its lifecycle, an aerosol will encounter changing physical parameters (temperature, pressure, relative humidity) and different chemical fields (O3, OH, NO3, halogens, etc.). The composition of the aerosol can evolve via condensational aging, heterogeneous chemistry aging and homogenous chemistry aging. Condensational aging occurs via the evaporation and condensation of semi-volatile species from the aerosol to gas phase. The hygroscopicity of the aerosol dictates the water content and to a large extent the size of the aerosol. Our group have recently investigated the role an evolving chemical environment has upon the size and mass of aerosol. These laboratory studies have used a mixture of electrodynamic balance, mass spectrometric, and spectroscopic methodologies to probe aerosol size and composition. In particular, the ozonolysis of organic aerosol, containing alkenyl moieties, will be discussed. It is found that short exposure times of aerosols to small ozone concentrations result in dramatic changes in the volatility and hygroscopicity of various types of organic aerosol. In some cases, previously non-volatile aerosols become significantly volatilized upon reaction with ozone. The phase of the ozone-attacked aerosol is important to the reaction mechanism. Furthermore the chemical aging of the organic fraction within mixed organic/inorganic aerosols is investigated. Mechanistic pathways and their atmospheric implications will be presented.

Pope, F. D.; Gallimore, P. J.; Griffiths, P. T.; Clegg, S. L.; Cox, R.; Kalberer, M.

2009-12-01

327

A Quantitative Determination of the Ammonia, Amino Nitrogen, Lactose, Total Acid, and Volatile Acid Content of Cows Milk  

Microsoft Academic Search

A quantitative determination of the ammollia, Bznlno nitrogen, lactose, total acid, and volatile acid content of 27 samples of commercial milk obtained from Baltimore dairies has been made within the past year. As this milk was to be used in a later bacteriological investigation, it was sterilized by autoclaving before being subjected to chemical analysis. AMMONIA Shaffer (1903) published a

Henrietta Lisk

1924-01-01

328

Effects of ascorbic acid and antioxidants on color, lipid oxidation and volatiles of irradiated ground beef  

NASA Astrophysics Data System (ADS)

Beef loins with 3 different aging times after slaughter were ground, added with none, 0.1% ascorbic acid, 0.01% sesamol+0.01% ?-tocopherol, or 0.1% ascorbic acid+0.01% sesamol+0.01% tocopherol. The meats were packaged in oxygen-permeable bags, irradiated at 2.5kGy, and color, oxidation-reduction potential (ORP), lipid oxidation and volatile profiles were determined. Irradiation decreased the redness of ground beef, and visible color of beef changed from a bright red to a green/brown depending on the age of meat. Addition of ascorbic acid prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. The ground beef added with ascorbic acid had lower ORP than control, and the low ORP of meat helped maintaining the heme pigments in reduced form. During aerobic storage, S-volatiles disappeared while volatile aldehydes significantly increased in irradiated beef. Addition of ascorbic acid at 0.1% or sesamol+?-tocopherol at each 0.01% level to ground beef prior to irradiation were effective in reducing lipid oxidation and S-volatiles. As storage time increased, however, the antioxidant effect of sesamol+tocopherol in irradiated ground beef was superior to that of ascorbic acid.

Ahn, D. U.; Nam, K. C.

2004-09-01

329

Volatile organic compounds (VOCs): Remediation for wastewater. (Latest citations from the Selected Water Resources Abstracts database). Published Search  

SciTech Connect

The bibliography contains citations concerning wastewater contamination by volatile organic materials and the technology for reclamation. Remediation techniques discussed include use of activated carbon, activated sludge, oxidation, scrubbing, vapor stripping, biodegradation, and other degradative treatments. Articles include remediation of soils contaminated by volatile wastes. The citations examine a variety of compounds, including aromatic hydrocarbons, petroleum wastes, chlorinated organics, and other volatile materials. (Contains a minimum of 215 citations and includes a subject term index and title list.)

Not Available

1993-11-01

330

Assessing the fate of biodegradable volatile organic contaminants in unsaturated soil filter systems  

NASA Astrophysics Data System (ADS)

The assessment of contaminant biodegradation in the subsurface is challenged by various abiotic processes leading to a reduction of contaminant concentration without a destructive mass removal of the contaminant. In unsaturated porous media, this interplay of processes is further complicated by volatilization. Many organic contaminants are sufficiently volatile to allow for significant fluxes from the water phase into the soil air, which can eventually lead to an emission of contaminants into the atmosphere. Knowledge of the magnitude of these emissions is thus required to evaluate the efficiency of bioremediation in such porous media and to estimate potential risks due to these emissions. In the present study, vertical flow constructed wetlands were investigated at the pilot scale as part of the SAFIRA II project. The investigated wetland system is intermittently irrigated by contaminated groundwater containing the volatile compounds benzene and MTBE. Measured concentration at the in- and outflow of the system demonstrate a high mass removal rate, but the highly transient flow and transport processes in the system challenge the quantification of biodegradation and volatilization and their contribution to the observed mass removal. By a combination of conservative solute tracer tests, stable isotope fractionation and measurements of natural radon concentration is the treated groundwater is was possible to determine the contribution of biodegradation and volatilization to total mass removal. The results suggest that for the investigated volatile compounds biodegradation is the dominating mass removal process with volatilization contributing only to minor or negligible amounts. These results can be confirmed by reactive transport simulations and were further supported by laboratory studies showing that also gas phase gradients of volatile compounds can be affected by biodegradation suggesting the unsaturated zone to act as a biofilter for contaminants in the soil air.

Thullner, Martin; de Biase, Cecilia; Hanzel, Joanna; Reger, Daniel; Wick, Lukas; Oswald, Sascha; van Afferden, Manfred; Schmidt, Axel; Reiche, Nils; Jechalke, Sven

2010-05-01

331

Acid volatile sulfide determination in sediments using elemental analyzer with thermal conductivity detector.  

PubMed

A method for the determination of acid volatile sulfides (AVS) in sediments, using a common elemental analyzer with thermal conductivity detector, is proposed. The method uses a mixture of Sn and V(2)O(5) for pyrolysis and combustion to determine total sulfur (TS), and non volatile sulfur (NVS), after an acidic attack. AVS is calculated as the difference between TS and NVS. The method for TS is validated by analyzing a certified reference material. The recovery in the determination of acid volatile sulfide is determined by spiking a river sediment with ZnS. The method is accurate and gives a good reproducibility, recovering 97.7-99.6% of the sulfur in the 0-3% total sulfur content, with SD of approximately 0.015%. PMID:18967479

Fiedler, H D; Rubio, R; Rauret, G; Casals, I

1999-02-01

332

Lewis-Acid/Base Effects on Gallium Volatility in Molten Chlorides  

SciTech Connect

It has been proposed that GaCl{sub 3} can be removed by direct volatilization from a Pu-Ga alloy that is dissolved in a molten chloride salt. Although pure GaCl{sub 3} is quite volatile (boiling point, 201 C), the behavior of GaCl{sub 3} dissolved in chloride salts is different due to solution effects and is critically dependent on the composition of the solvent salt (i.e., its Lewis-acid/base character). In this report, the behavior of gallium in prototypical Lewis-acid and Lewis-base salts is compared. It was found that gallium volatility is suppressed in basic melts and enhanced in acidic melts. The implications of these results on the potential for simple gallium removal in molten salt systems are significant.

Williams, D.F.

2001-02-26

333

Partition of Volatile Organic Compounds in Activated Sludge and Wastewater  

Microsoft Academic Search

The Henrys law constant is important in the gas-liquid mass transfer process. Apparent dimensionless Henrys law constant, or the gas-liquid partition coefficient (KH), for both hydrophilic (methanol, isopropyl alcohol, and acetone) and hydrophobic (toluene and p-xylene) organic compounds in deionized (DI) water, a wastewater with a maximum total dissolved organic carbon (DOC) content of 700 mg\\/L, and DI water mixed

Jun-Hong Lin; Ming-Shean Chou

2006-01-01

334

Emission of ozone and organic volatiles from a selection of laser printers and photocopiers.  

PubMed

To estimate the impact of office equipment on the quality of indoor air, the emission of ozone and organic volatiles was measured from one photocopier and four laser printers, three of which operated according to traditional corona discharge technology. The laser printers equipped with traditional technology emitted significant amounts of ozone and formaldehyde. Lesser amounts of other volatile aldehydes were emitted during printing. The photocopier emitted mainly ozone. In a well-ventilated office environment, the amounts encountered here for individual volatiles were within recommended maximum exposure limits for a reasonable density of printers. Because it is not known whether the concentration of irritating volatiles, such as formaldehyde, should be kept lower in an ozone rich environment or not, and because emissions in the immediate vicinity of the printers exceeded recommendations, the authors recommend that laser printers equipped with the traditional corona rods not be placed beside or immediately at the working site of office personnel. This way, ozone concentrations can be kept below recommended maximum exposure limits, provided that the ventilation rate is adequate. Further, it seems that if a reliable quantitative comparison of total organic volatiles prior to and during printing is to be made, the inertness of the sorbent toward ozone should be confirmed. PMID:10957818

Tuomi, T; Engstrm, B; Niemel, R; Svinhufvud, J; Reijula, K

2000-08-01

335

FIELD AUDIT RESULTS WITH ORGANIC GAS STANDARDS ON VOLATILE ORGANIC AMBIENT AIR SAMPLERS EQUIPPED WITH TENAX GC (GAS CHROMATOGRAPHY)  

EPA Science Inventory

The results from two field audits of Tenax-equipped sampling systems measuring the volatile organic (VOC) concentrations in ambient air are reported. The audited samplers collected the VOC's on Tenax GC (a solid adsorbent) with the VOC's later thermally desorbed and then analyzed...

336

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 ...

337

Development of Oxide Semiconductor Thick Film Gas Sensor for the Detection of Total Volatile Organic Compounds  

Microsoft Academic Search

After an amendment of Building Standards Law in 2003, the installation of the ventilator is compulsory in the newly built house. Because many persons suffer from indoor-air pollutants caused by the volatile organic compounds (VOCs). The final purpose of this research is to develop the gas sensor which can monitor the gross weight of VOC gases indoors and then to

Masahiro Kadosaki; Yuichi Sakai; Ikuo Tamura; Ichiro Matsubara; Toshio Itoh

2008-01-01

338

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...

339

Development of the colorimetric sensor array for detection of explosives and volatile organic compounds in air  

NASA Astrophysics Data System (ADS)

In the framework of the research project 'Xsense' at the Technical University of Denmark (DTU) we are developing a simple colorimetric sensor array which can be useful in detection of explosives like DNT and TNT, and identification of volatile organic compounds in the presence of water vapor in air. The technology is based on an array of chemo-responsive dyes immobilized on a solid support. Upon exposure to the analyte in suspicion the dye array changes color. Each chosen dye reacts chemo selectively with analytes of interest. A change in a color signature indicates the presence of unknown explosives and volatile organic compounds (VOCs). We are working towards the selection of dyes that undergo color changes in the presence of explosives and VOCs, as well as the development of an immobilization method for the molecules. Digital imaging of the dye array before and after exposure to the analytes creates a color difference map which gives a unique fingerprint for each explosive and volatile organic compound. Such sensing technology can be used to screen for relevant explosives in a complex background as well as to distinguish mixtures of volatile organic compounds distributed in gas phase. This sensor array is inexpensive, and can potentially be produced as single use disposable.

Kostesha, N. V.; Alstrm, T. S.; Johnsen, C.; Nilesen, K. A.; Jeppesen, J. O.; Larsen, J.; Jakobsen, M. H.; Boisen, A.

2010-04-01

340

Abundances and Flux Estimates of Volatile Organic Compounds from a Dairy Cowshed in Germany  

Microsoft Academic Search

Animal husbandry and manure treatment have been specifi cally documented as signifi cant sources of methane, ammonia, nitrous oxide, and particulate matter. Although volatile organic compounds (VOCs) are also produced, much less information exists concerning their impact. We report on chemical ionization mass spectrometry and photo-acoustic spectroscopy measurements of mixing ratios of VOCs over a 2-wk measurement period in a

Ngwa Martin Ngwabie; Gunnar W. Schade; Thomas G. Custer; Stefan Linke; Torsten Hinz

2008-01-01

341

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

Microsoft Academic Search

Law enforcement agencies frequently use canines trained to detect the odor of human decomposition to aid in determining the location of clandestine burials and human remains deposited or scattered on the surface. However, few studies attempt to identify the specific volatile organic compounds (VOCs) that elicit an appropriate response from victim recovery (VR) canines. Solid-phase microextraction (SPME) was combined with

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

2009-01-01

342

Indoor\\/Outdoor Measurements of Volatile Organic Compounds in the Kanawha Valley of West Virginia  

Microsoft Academic Search

The Kanawha Valley region of West Virginia which is comprised of Charleston and surrounding communities Is the center of a heavily industrialized area known for its chemical manufacturing. As part of a larger study designed to investigate the Impact of the chemical industry on human exposures to volatile organic compounds (VOC), a study of the relationship between indoor and outdoor

Martin A. Cohen; P. Barry Ryan; Yukio Yanagisawa; John D. Spengler; Halk zkaynak; Paul S. Epstein

1989-01-01

343

VOLATILE ORGANIC COMPOUNDS IN THE AMBIENT ATMOSPHERE OF THE NEW JERSEY, NEW YORK AREA  

EPA Science Inventory

From 1979 through 1981 data were collected on selected volatile organics in the ambient atmosphere of New Jersey and New York. The sites selected included urban, suburban rural, and industrial areas: Newark, Rutherford, South Amboy, Elizabeth, Camden and Batsto Village in New Jer...

344

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...

345

Aqueous Extraction-Headspace/Gas Chromatographic Method for Determination of Volatile Organic Compounds in Soils.  

National Technical Information Service (NTIS)

This study compares aqueous extraction-headspace/Gas Chromatography (GC) and the EPA SW-846 purge-and-trap-gas chromatography/mass spectrometry(Method 8240)for the determination of four common Volatile Organic Compounds (VOCs) in soils. Comparisons were m...

A. D. Hewitt P. H. Miyares D. C. Leggett T. F. Jenkins

1992-01-01

346

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 gCg?1 ...

347

VOLATILE ORGANIC HYDROCARBON AND ALDEHYDE COMPOSITION IN RALEIGH, NORTH CAROLINA DURING THE 1985 WOODSMOKE STUDY  

EPA Science Inventory

Initial field tests for collection of volatile organic hydrocarbons and aldehydes under EPA's Integrated Air Cancer Project (IACP) were held in Raleigh, NC during the winter of 1985. Sampling was conducted during 12 hour (7:00-7:00) daytime or nighttime periods. Hydrocarbons were...

348

Barbecue charcoal combustion as a potential source of aromatic volatile organic compounds and carbonyls  

Microsoft Academic Search

The emission concentrations of a number of aromatic volatile organic compounds (VOCs) and carbonyl compounds were quantified during the combustion of commonly used barbecue charcoal. The concentrations of VOC and carbonyls were determined by gas chromatography coupled with thermal desorption and HPLC method, respectively. The analysis of VOC emission concentrations showed that toluene (116444ppb) was the most abundant. On the

Ehsanul Kabir; Ki-Hyun Kim; Ji-Won Ahn; Jong Ryeul Sohn

2010-01-01

349

COLD TRAPPING OF VOLATILE ORGANIC COMPOUNDS ON FUSED SILICA CAPILLARY COLUMNS  

EPA Science Inventory

A 30m, 0.25mm ID, fused silica capillary column at temperatures from -60 to -100C has been shown to be a quantitative trap for organic compounds with volatilities ranging from that of 1.1-dichloroethene to that of chlorobenzene. This type of 'whole column cryotrapping' provided s...

350

HISTORIC EMISSIONS OF VOLATILE ORGANIC COMPOUNDS IN THE UNITED STATES FROM 1900 TO 1985  

EPA Science Inventory

The report gives an estimate of historic emissions of volatile organic compounds (VOCs) for each state (and the District of Columbia) of the contiguous U.S. Annual emissions were estimated on the national level from 1960 to 1985. For 1940, 1950, and every fifth year from 1960 to ...

351

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...

352

Core-Based Intrinsic Fiber-Optic Absorption Sensor for the Detection of Volatile Organic Compounds  

Microsoft Academic Search

A core-based intrinsic fiber-optic absorption sensor has been developed and tested for the detection of volatile organic compounds. The distal ends of transmitting and receiving fibers are connected by a small cy- lindrical section of an optically clear silicone rubber. The silicone rubber acts both as a light pipe and as a selective membrane into which the analyte molecules can

Gregory L. Klunder; Richard E. Russo

1995-01-01

353

NATURAL VOLATILE ORGANIC SUBSTANCES AND THEIR EFFECT ON AIR QUALITY IN THE UNITED STATES (REVIEW)  

EPA Science Inventory

Large quantities of volatile organic substances are emitted from mobile and stationary sources in the United States. When the US, east of 105 west longitude is divided into 80 by 80 km grids, most of these grid areas east of the Mississippi River and many west of the river, have ...

354

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...

355

INHIBITION OF HUMAN A7 NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS BY THE VOLATILE ORGANIC SOLVENT TRICHLOROETHYLENE.  

EPA Science Inventory

Volatile organic compounds such as toleune, trichloroethylene and perchloroethylene are potent and reversible blockers of voltage-gated calcium current in nerve growth factor (NGF)-differentiated pheochromocytoma (PC12) cells. It is hypothesized that effects of VOCs on ICa contri...

356

A GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES  

EPA Science Inventory

As part of an effort to assess the potential impacts associated with global climate change, the U.S. Environmental Protection Agency's Office of Research and Development is supporting global atmospheric chemistry research by developing global scale estimates of volatile organic c...

357

Sampling Throughout The Hydrologic Cycle To Characterize Sources Of Volatile Organic Compounds In Ground Water  

Microsoft Academic Search

Results of three studies in New Jersey demonstrate that analysis of samples collected throughout the hydrologic cycle can improve understanding of the sources of volatile organic compounds (VOCs) in ambi- ent ground water. Results of the first study indicate that atmospheric concentrations of methyl-tert butyl ether (MTBE) are sufficiently high to cause detection in ground water, whereas atmospheric concentrations of

Arthur L. Baehr; Leon J. Kauffman; Emmanuel G. Charles; Ronald J. Baker

358

Volatile Organic Compounds in the Po Basin. Part B: Biogenic VOCs  

Microsoft Academic Search

Measurements of volatile organic compounds (VOCs) were performed in the Po Basin, northern Italy in early summer 1998, summer 2002, and autumn 2003. During the three campaigns, trace gases and meteorological parameters were measured at a semi-rural station, around 35 km north of the city center of Milan. Bimodal diurnal cycles of isoprene with highest concentrations in the morning and

M. Steinbacher; J. Dommen; C. Ordonez; S. Reimann; F. C. Grebler; J. Staehelin; S. Andreani-Aksoyoglu; A. S. H. Prevot

2005-01-01

359

Rapid aqueous sample extraction of volatile organic compounds: effect of sample matrix and analyte properties  

Microsoft Academic Search

Studies have been done using a rapid aqueous sample extraction (RASE) system to characterize the effects of chemical properties on the time required for removal of volatile organic compounds (VOCs) to the gas phase. These analyses include determinations of the effects that different analytes, and modifications to the matrix, have on extraction time. Experiments were performed to determine the distinct

Melissa J. Meyer; Mary F. Gress; Anthony J. Borgerding

2001-01-01

360

ASSESSMENT OF NATURAL VOLATILE ORGANIC SUBSTANCES AND THEIR EFFECT ON AIR QUALITY IN THE UNITED STATES  

EPA Science Inventory

This research brief is a summary of the extensive review and critical analysis of the literature on natural volatile organic substances, sometimes referred to as biogenic hydrocarbons, and an assessment of that body of scientific information. The review is reported separately (Na...

361

Spatial variation of volatile organic compounds in a Hot Spot for air pollution  

Microsoft Academic Search

The spatial variations of volatile organic compounds (VOCs) were characterized in the Village of Waterfront South neighborhood (WFS), a hot spot for air toxics in Camden, NJ. This was accomplished by conducting spatial saturation sampling for 11 VOCs using 3500 OVM passive samplers at 22 sites in WFS and 16 sites in Copewood\\/Davis Streets (CDS) neighborhood, an urban reference area

Xianlei Zhu; Xiangmei Wu; Qingyu Meng; Sheng-wei Wang; Xiaogang Tang; Pamela Ohman-Strickland; Panos Georgopoulos; Junfeng Zhang; Linda Bonanno; Joann Held; Paul Lioy

2008-01-01

362

Volatile organic compound emissions from automobile refinishing: Background information for promulgated standards. Final report  

SciTech Connect

A final rule for the regulation of volatile organic compounds (VOC) from automobile refinishing is being promulgated under the authority of Section 183(e) of the Clean Air Act. This document contains comments received from the public, and the EPA`s responses to these comments.

NONE

1998-08-01

363

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...

364

Application of headspace analysis for the determination of volatile organic compounds in contaminated soils  

Microsoft Academic Search

It has been shown that headspace analysis is more reliable than the purge?and?trap method for the quantification of volatile organic compounds (VOCs) in soil samples. The major shortcoming of the headspace analysis in the case of soil samples is the inability of water to fully extract the soil contaminants. Experiments were conducted to fully understand the limitations and applicability of

S. G. Pavlostathis; G. N. Mathavan

1992-01-01

365

In situ measurement of volatile organic compounds in groundwater by methods coupled to the cone penetrometer.  

National Technical Information Service (NTIS)

The objective of this investigation is to interface an in situ, on-line sparging system with a cone penetrometer to provide direct analysis of volatile organic compounds (VOCS) in groundwater by on-site analysis. Transfer line materials (15 m (times) 0.16...

P. V. Doskey J. H. Aldstadt J. M. Kuo M. S. Costanza M. D. Erickson

1995-01-01

366

Volatile organic compound emissions from automobile refinishing. Background information for proposed standards. Draft report  

SciTech Connect

A draft rule for the regulation of volatile organic compounds (VOC) from automible refinishing is being proposed under the authority of Section 183(e) of the Clean Air Act. This document contains information on the automobile refinish industry, and presents control options and their associated environmental and cost impacts.

NONE

1995-08-01

367

Human exposure to volatile organic compounds in household tap water: the indoor inhalation pathway  

Microsoft Academic Search

This paper addresses the quantification of human exposure to volatile organic compounds (VOC's) as a result of mass transfer from tap water to indoor air. A three-compartment model is developed and used to simulate the 24-h concentration profile within the shower, bathroom, and remaining household volumes of a dwelling. Mass transfers from water to air are derived from measured data

Thomas E. McKone

1987-01-01

368

A proton transfer reaction mass spectrometry based system for determining plant uptake of volatile organic compounds  

Microsoft Academic Search

In order to evaluate the contribution that higher plants make to the removal of volatile organic compounds from the atmosphere, a measurement system consisting of a proton transfer reaction mass spectrometer (PTR-MS), CO2 analyzer, diffusion devise and leaf enclosure was established. The uptake of VOCs by Golden Pothos (Epipremnum aureum) was investigated. The overall relative error associated with measurements made

Akira Tani; Shungo Kato; Yoshizumi Kajii; Michael Wilkinson; Sue Owen; Nick Hewitt

2007-01-01

369

Direct characterization and quantification of volatile organic compounds by piezoelectric module chips sensor  

Microsoft Academic Search

Although various gas sensors have been developed for the detection of volatile organic compounds (VOCs), the simultaneous detection and identification of several targets by application of biomaterials together with chemicals are rare in one sensor system. In this study a six chips sensor module coated with synthetic polypeptides together with conducting polymers is used for the simultaneous detection and identification

Hsin-Hsien Lu; Yerra Koteswara Rao; Tzong-Zeng Wu; Yew-Min Tzeng

2009-01-01

370

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,...

371

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. A shell-and-tube heat-exchange type of hollow fiber module was considered for treatment of a wastewater containing toluen...

372

Source identification and apportionment of volatile organic compounds in Houston, TX  

Microsoft Academic Search

Hourly concentrations of ambient volatile organic compounds (VOCs) were analyzed between June and October 2003 at three sites, in order to further understand emissions of VOCs in the Houston area. Ambient concentrations of 54 VOCs from three monitoring sites in the heavily industrialized Houston Ship Channel were analyzed using positive matrix factorization (PMF). Hourly concentrations were divided into weekly data

Birnur Buzcu; Matthew P. Fraser

2006-01-01

373

Contribution of Volatile Organic Compounds to Nigeria's Airshed by Petroleum Refineries  

Microsoft Academic Search

The emission factor approach was employed to predict the emission potential of volatile organic compounds (VOCs) from both operating and proposed petroleum refineries in Nigeria. The emission sources from the refineries (4 operating and 14 newly licensed) were classified as point and area with anticipated VOC release into the environment estimated. The overall contribution was also estimated using human population

J. A. Sonibare; F. A. Akeredolu; E. O.-O. Obanijesu; F. M. Adebiyi

2007-01-01

374

Volatile organic compound emissions from wastewater treatment plants in Taiwan: Legal regulations and costs of control  

Microsoft Academic Search

This study assessed volatile organic compound (VOC) emission characteristics from wastewater treatment plants (WWTPs) in five Taiwanese industrial districts engaged in numerous manufacturing processes, including petrochemical, science-based industry (primarily semiconductors, photo-electronics, electronic products and biological technology), as well as multiple manufacturing processes (primarily pharmaceuticals and paint manufacturing). The most aqueous hydrocarbons dissolved in the wastewater of Taiwanese WWTPs were acetone,

Wen-Hsi Cheng; Shu-Kang Hsu; Ming-Shean Chou

2008-01-01

375

Source Location and Characterization of Volatile Organic Compound Emissions at a Petrochemical Plant in Kaohsiung, Taiwan  

Microsoft Academic Search

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 chromatographymass spectrometry. The survey covered

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

2005-01-01

376

Study on Sources of Volatile Organic Compounds (CMB) in Pearl River Delta region, China  

Microsoft Academic Search

The profiles of major Volatile organic compounds (VOCs) sources including vehicle exhaust, gasoline vapor, painting, asphalt, liquefied petroleum gas (LPG), biomass burning and petrochemical industry in Pearl River Delta were experimentally determined. Source samples were taken by using dilution chamber for mobile and stationary sources, laboratory simulation for biomass burning. The concentrations of 108 VOC species of sources were quantified

Y. Liu; M. Shao; S. Lu; C. Chang; C. J. Wang; B. Wang

2007-01-01

377

Volatile organic compound concentrations in ambient air of Kaohsiung petroleum refinery in Taiwan  

Microsoft Academic Search

The air quality assessment for volatile organic compounds (VOC) was conducted in and around Chinese petroleum corporation (CPC) refinery at Kaohsiung, located in southern Taiwan, during 2001 by collecting air samples at 26 sites. Benzene and toluene were detected as the most abundant VOC by both gas chromatography and ultra-violet differential optical absorption spectroscopy (UV-DOAS) techniques. BTXE concentrations showed day

Tsai-Yin Lin; Usha Sree; Sen-Hong Tseng; Kong Hwa Chiu; Chien-Hou Wu; Jiunn-Guang Lo

2004-01-01

378

Ambient volatile organic compound (VOC) concentrations around a petrochemical complex and a petroleum refinery  

Microsoft Academic Search

Air samples were collected between September 2000 and September 2001 in Izmir, Turkey at three sampling sites located around a petrochemical complex and an oil refinery to measure ambient volatile organic compound (VOC) concentrations. VOC concentrations were 420-fold higher than those measured at a suburban site in Izmir, Turkey. Ethylene dichloride, a leaded gasoline additive used in petroleum refining and

Eylem Cetin; Mustafa Odabasi; Remzi Seyfioglu

2003-01-01

379

Data mining of the relationship between volatile organic components and transient high ozone formation  

Microsoft Academic Search

The aim of this study is to identify relationships between volatile organic components (VOCs) and transient high ozone formation in the Houston area. The ozone is not emitted to the atmosphere directly but is formed by chemical reactions in the atmosphere. In Houston, short-term (1h) sharp increases are observed followed by a rapid decrease back to typical concentrations. Automatic gas

Feng Gan; Philip K. Hopke

2003-01-01

380

Polymer coated quartz crystal microbalance sensors for detection of volatile organic compounds in gas mixtures  

Microsoft Academic Search

By coating different conducting polymers of thiophene and its derivatives on quartz crystal microbalance (QCM) sensor surfaces, new novel QCM gas sensors have been produced in two simple ways, which could classify testing gas samples of volatile organic compounds (VOCs) gases. Principle components analysis (PCA) has been performed based on the QCM measurement results, which shows that our QCM sensors

Pengchao Si; John Mortensen; Alexei Komolov; Jens Denborg; Preben Juul Mller

2007-01-01

381

DEVELOPMENT OF A SAMPLER FOR PARTICULATE-ASSOCIATED AND LOW VOLATILITY ORGANIC POLLUTANTS IN RESIDENTIAL AIR  

EPA Science Inventory

The report describes the development of a sampler for particulate-associated and low volatility organic pollutants in residential air. The performance of the sampler inlet, which is compatible with the proposed PM-10 regulations for particulate sampling, is documented under a var...

382

Biogenic volatile organic compound emissions from a lowland tropical wet forest in Costa Rica  

Microsoft Academic Search

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 3550% of the total basal area of old-growth forest on the major edaphic site types, indicating that a high proportion of the

Chris Geron; Alex Guenther; Jim Greenberg; Henry W. Loescher; Deborah Clark; Brad Baker

2002-01-01

383

PERFORMANCE EVALUATION MATERIALS FOR THE ANALYSIS OF VOLATILE ORGANIC CONTAMINANTS IN SOILS: A PRELIMINARY ASSESSMENT  

EPA Science Inventory

During an evaluation of field portable gas chromatographs (GC), site-specific performance evaluation materials (PEM) were prepared and used as quality control samples. lean soils from two contaminated sites were spiked with various volatile organic compounds. he PEM were shipped ...

384

Treatment of volatile organic contaminants in a vertical flow filter: Relevance of different removal processes  

Microsoft Academic Search

Vertical flow filters and vertical flow constructed wetlands are established wastewater treatment systems and have also been proposed for the treatment of contaminated groundwater. This study investigates the removal processes of volatile organic compounds in a pilot-scale vertical flow filter. The filter is intermittently irrigated with contaminated groundwater containing benzene, MTBE and ammonium as the main contaminants. The system is

Cecilia De Biase; Daniel Reger; Axel Schmidt; Sven Jechalke; Nils Reiche; Paula M. Martnez-Lavanchy; Mnica Rosell; Manfred Van Afferden; Uli Maier; Sascha E. Oswald; Martin Thullner

2011-01-01

385

Intercomparison of oxygenated volatile organic compound measurements at the SAPHIR atmosphere simulation chamber  

Microsoft Academic Search

This paper presents results from the first large-scale in situ intercomparison of oxygenated volatile organic compound (OVOC) measurements. The intercomparison was conducted blind at the large (270 m3) simulation chamber, Simulation of Atmospheric Photochemistry in a Large Reaction Chamber (SAPHIR), in Jlich, Germany. Fifteen analytical instruments, representing a wide range of techniques, were challenged with measuring atmospherically relevant OVOC species

E. C. Apel; T. Brauers; R. Koppmann; B. Bandowe; J. Bomeyer; C. Holzke; R. Tillmann; A. Wahner; R. Wegener; A. Brunner; M. Jocher; T. Ruuskanen; C. Spirig; D. Steigner; R. Steinbrecher; E. Gomez Alvarez; K. Mller; J. P. Burrows; G. Schade; S. J. Solomon; A. Ladsttter-Weienmayer; P. Simmonds; D. Young; J. R. Hopkins; A. C. Lewis; G. Legreid; S. Reimann; A. Hansel; A. Wisthaler; R. S. Blake; A. M. Ellis; P. S. Monks; K. P. Wyche

2008-01-01

386

Heterogeneous Adsorption Characteristics of Volatile Organic Compounds (VOCs) on MCM?48  

Microsoft Academic Search

This work focuses on the fundamental studies of heterogeneous adsorption characteristics of mesoporous adsorbent. MCM?48 was synthesized to investigate the adsorption properties of eight different volatile organic compounds (benzene, cyclohexane, n?hexane, toluene, methanol, acetone, methyl ethyl ketone (MEK), and trichloroethylene (TCE)). The gravimetric method was used to measure the adsorption equilibrium amount. Several simple and reliable methods such as isosteric

W. G. Shim; J. W. Lee; H. Moon

2006-01-01

387

Source Apportionment of Ambient Volatile Organic Compounds in Bursa, a Heavily Industrialized City in Turkey  

Microsoft Academic Search

Weekly passive sampling campaigns were carried out over two sample periods to measure volatile organic compounds (VOCs) in Bursa, one of the most heavily industrialized cities in Turkey. The measurements, taken at 40 points in October 2005 and 49 points in April 2006, revealed concentrations of 34 VOCs, including aromatics, olefins, paraffin and halogenated compounds; with benzene, toluene, ethylbenzene, and

Mihriban Yilmaz Civan; znur O?uz Kuntasal; Grdal Tuncel

2011-01-01

388

SCREENING PROCESSED MILK FOR VOLATILE ORGANIC COMPOUNDS USING VACUUM DISTILLATION/GAS CHROMATOGRAPHY/MASS SPECTROMETRY  

EPA Science Inventory

An adaptation of Office of Solid Waste and Emergency Response' Test Methods for Evaluating Solid Waste Physical/Chemical Methods (SW-846) method 8261 to analyze milk for an expanded list of volatile organic compounds is presented. The milk matriz exhibits a strong affinity for o...

389

FIELD EVALUATION OF VOLATILE ORGANIC COMPOUND REMOVAL EFFICIENCY FOR FULL-SCALE CARBON ADSORPTION SYSTEMS  

EPA Science Inventory

Six full-scale, fixed-bed carbon adsorption systems were tested for vapor-phase volatile organic compound removal efficiency. Solvents used in the systems included methyl ethyl ketone, isopropyl acetate, tetrahydrofuran and toluene. One year after the first tests, repeat testing ...

390

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...

391

MODELING OF MULTICOMPONENT PERVAPORATION FOR REMOVAL OF VOLATILE ORGANIC COMPOUNDS FROM WATER  

EPA Science Inventory

A resistance-in-series model was used to study the pervaporation of multiple volatile organic compounds (VOCs)-water mixtures. Permeation experiments were carried out for four membranes: poly(dimethylsiloxane) (PDMS), polyether-block-polyamides (PEBA), polyurethane (PUR) and sil...

392

Analysis of selected volatile organic compounds associated with residential kerosene heater use  

Microsoft Academic Search

Volatile organic species, including aliphatic hydrocarbons from hexane through dodecane, cyclohexane and the aromatic species benzene, toluene, ethyl benzene, nitrobenzene, ortho?, meta?, paraxylenes, styrene and naphthalene, associated with residential kerosene heater emissions, were measured at two sites: a small campus room (at NJIT) and living\\/dining room in a residence in Elizabeth, NJ. The analytical procedure involved collection of a series

Joseph W. Bozzelli; Barbara Kebbekus; Catherine Bobenhausen

1995-01-01

393

Plant Volatile Organic Compounds (VOCs) in Ozone (O-3) Polluted Atmospheres: The Ecological Effects  

Microsoft Academic Search

Tropospheric ozone (O-3) is an important secondary air pollutant formed as a result of photochemical reactions between primary pollutants, such as nitrogen oxides (NOx), and volatile organic compounds (VOCs). O-3 concentrations in the lower atmosphere (troposphere) are predicted to continue increasing as a result of anthropogenic activity, which will impact strongly on wild and cultivated plants. O-3 affects photosynthesis and

Delia M. Pinto; James D. Blande; Silvia R. Souza; Anne-Marja Nerg; Jarmo K. Holopainen

2010-01-01

394

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...

395

SEPARATION AND ISOLATION OF VOLATILE ORGANIC COMPOUNDS USING VACUUM DISTILLATION WITH GS/MS DETERMINATION  

EPA Science Inventory

The U.S. EPA's vacuum distillation of water, soil, oil, and fish samples is presented as an alternative technique for determining volatile organic compounds. nalysis of samples containing VOCs and non-VOCs at 50 ppb concentrations were performed to evaluate method limitations. na...

396

Internal Standards: A Source of Analytical Bias For Volatile Organic Analyte Determinations  

EPA Science Inventory

The use of internal standards in the determination of volatile organic compounds as described in SW-846 Method 8260C introduces a potential for bias in results once the internal standards (ISTDs) are added to a sample for analysis. The bias is relative to the dissimilarity betw...

397

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...

398

Compositions of Volatile Organic Compounds Emitted from Melted Virgin and Waste Plastic Pellets  

Microsoft Academic Search

To characterize potential air pollution issues related to recycling facilities of waste plastics, volatile organic compounds (VOCs) emitted from melted virgin and waste plastics pellets were analyzed. In this study, laboratory experiments were performed to melt virgin and waste plastic pellets under various temperatures (150, 200, and 250 C) and atmospheres (air and nitrogen [N2]). In the study presented here,

Kyoko Yamashita; Naomichi Yamamoto; Atsushi Mizukoshi; Miyuki Noguchi; Yueyong Ni; Yukio Yanagisawa; Richard Hoffbeck; Yongping Li; Guohe Huang; James Schwab; John Spicer; Kenneth Demerjian; Mark Gibson; Judith Guernsey; Stephen Beauchamp; David Waugh; Mathew Heal; Jeffrey Brook; Robert Maher; Graham Gagnon; Johnny McPherson; Barbara Bryden; Richard Gould; Liming Zhou; Philip Hopke; Weixiang Zhao; Elisabeth Hawley; Neven Kresic; Alexandra Wright; Michael Kavanaugh; Pat Saathoff; Amit Gupta; Ted Stathopoulos; Louis Lazure; ABM Khan; Nigel Clark; Mridul Gautam; W. Wayne; Gregory Thompson; Donald Lyons; Yu-Ming Kuo; Yasuhiro Fukushima

2009-01-01

399

Diffusion-controlled reference material for volatile organic compound emissions testing: Pilot inter-laboratory study  

Microsoft Academic Search

To improve the reliability and accuracy of tests used to measure emissions of volatile organic compounds (VOCs) from samples of interior building products, the National Institute of Standards and Technology (NIST) and Virginia Tech (VT) have created a program to develop reference materials with independently predictable emission rates. A diffusive reference material and associated mechanistic model have been developed and

Cynthia Howard-Reed; Zhe Liu; Jennifer Benning; Steven Cox; Daniel Samarov; Dennis Leber; Alfred T. Hodgson; Stephany Mason; Doyun Won; John C. Little

2011-01-01

400

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...

401

Performance specifications for technology development: Application for characterization of volatile organic compounds in the environment  

Microsoft Academic Search

This report contains information about technology development for the monitoring and remediation of environmental pollution caused by the release of volatile organic compounds. Topics discussed include: performance specification processes, gas chromatography, mass spectrometer, fiber-optic chemical sensors, infrared spectroscopy, Raman spectroscopy, piezoelectric sensors and electrochemical sensors. These methods are analyzed for their cost efficiency, accuracy, and the ability to meet the

S. E. Carpenter; P. V. Doskey; M. D. Erickson; P. C. Lindahl

1994-01-01

402

Machine learning methods on exhaled volatile organic compounds for distinguishing COPD patients from healthy controls  

Microsoft Academic Search

Exhaled volatile organic compounds (VOCs) have shown promise in diagnosing chronic obstructive pulmonary disease (COPD) but studies have been limited by small sample size and potential confounders. An investigation was conducted in order to establish whether combinations of VOCs could identify COPD patients from age and BMI matched controls. Breath samples were collected from 119 stable COPD patients and 63

Chris O Phillips; Yasir Syed; Neil Mac Parthalin; Reyer Zwiggelaar; Tim C Claypole; Keir E Lewis

2012-01-01

403

LONG-TERM STUDY OF VOLATILE ORGANIC COMPOUND RECOVERY FROM AMPULATED, DRY, FORTIFIED SOILS  

EPA Science Inventory

Our objective was to evaluate the stability and extractability of volatile organic compound (VOCs) when fortified on dry soils and stored in sealed ampules. Two desiccator-dried soils were fortified with eight neat VOCs, benzene,toluene,ethylbenzene,o-xylene,1,1,1-trichloroethane...

404

Volatile Organic Compounds in Ground Water From Rural Private Wells, 1986 to 1999  

Microsoft Academic Search

The U.S. Geological Survey (USGS) collected or compiled data on volatile organic compounds (VOCs) in samples of untreated ground water from 1,926 rural private wells during 1986 to 1999. At least one VOC was detected in 12 percent of samples from rural private wells. Individual VOCs were not commonly detected with the seven most frequently detected compounds found in only

Michael J. Moran; Wayne W. Lapham; Barbara L. Rowe; John S. Zogorski

2004-01-01

405

Volatile chlorinated organic compound levels in rain water from Kobe City in Japan  

Microsoft Academic Search

Water pollution by volatile chlorinated organic compounds has become a serious environmental problem. The Environmental Agency of Japan has defined the regulations on trichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane and carbon tetrachloride in wastewater in 1989. In order to protect against water pollution, it is important to keep concentrations in these compounds in environmental water as low as possible. Therefore, the determination of

Atsuko Adachi; Tadashi Kobayashi

1994-01-01

406

Volatile Organic Compound Emissions from Municipal Solid Waste Disposal Sites: A Case Study of Mumbai, India  

Microsoft Academic Search

Improper solid waste management leads to aesthetic and environmental problem. Emission of volatile organic compounds is one of the problems from uncontrolled dumpsite. VOCs are well known to be hazardous to human health and are many of them are known or potential carcinogens. They also contribute to ozone formation at ground level and climate change as well. The qualitative and

Dipanjali Majumdar; Anjali Srivastava

2012-01-01

407

EXTRACTION METHODS FOR RECOVERY OF VOLATILE ORGANIC COMPOUNDS FROM FORTIFIED DRY SOILS  

EPA Science Inventory

Recovery of 8 volatile organic compounds (VOCs) from dry soils, each fortified at 800 ng/g soil, was studied in relation to the extraction method and time of extraction. Extraction procedures studied on desiccator-dried soils were modifications of EPA low-and high-level purge-and...

408

Volatile organic compound emissions in relation to plant carbon fixation and the terrestrial carbon budget  

Microsoft Academic Search

A substantial amount of carbon is emitted by terrestrial vegetation as biogenic volatile organic compounds (VOC), which contributes to the oxidative capacity of the atmosphere, to particle production and to the carbon cycle. With regard to the carbon budget of the terrestrial biosphere, a release of these carbon compounds is regarded as a loss of photosynthetically fixed carbon. The significance

Jrgen Kesselmeier; Paolo Ciccioli; Uwe Kuhn; Paolo Stefani; Thomas Biesenthal; Stefanie Rottenberger; Annette Wolf; Marina Vitullo; Ricardo Valentini; Antonio Nobre; Pavel Kabat; Meinrat O. Andreae

2002-01-01

409

THIN-FILM EVAPORATION AS A PRETREATMENT TECHNIQUE FOR REMOVING VOLATILE ORGANICS FROM PETROLEUM REFINERY WASTES  

EPA Science Inventory

Oily wastes from petroleum refineries can result in air emissions during the land treatment of these wastes. A pilot-scale thin film evaporator (TFE) was used to remove volatile organics (VO) from refinery tank bottom sludge. Different TFE operating parameters were utilized to de...

410

Symptoms of Mothers and Infants Related to Total Volatile Organic Compounds in Household Products  

Microsoft Academic Search

The authors sought to determine whether reported symptoms of mothers and infants were associated significantly with the use of household products that raised indoor levels of total volatile organic compounds (TVOCs). Data collected from 170 homes within the Avon Longitudinal Study of Parents and Children (ALSPAC: a large birth cohort of more than 10,000) had determined which household products were

Alexandra Farrow; Hazel Taylor; Kate Northstone; Jean Golding

2003-01-01

411

Attenuation of Methane and Volatile Organic Compounds in Landfill Soil Covers  

Microsoft Academic Search

trace components originate from hazardous materials deposited in the landfill or from biological or chemical The potential for natural attenuation of volatile organic compounds degradation of materials disposed of in the landfill. Due (VOCs) in landfill covers was investigated in soil microcosms incu- bated with methane and air, simulating the gas composition in landfill to pressure and concentration gradients, the

Charlotte Scheutz; Hans Mosbk; Peter Kjeldsen

2004-01-01

412

TEMPERATURE-DEPENDENT COLLECTION EFFICIENCY OF A CRYOGENIC TRAP FOR TRACE-LEVEL VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

Reduced temperature preconcentration of volatile organic compounds in a packed trap is examined experimentally as a function of trapping temperatures ranging from -180C to +100C. Trapped compounds are thermally desorbed into a capillary column-equipped gas chromatograph and quant...

413

STORAGE STABILITY OF VOLATILE ORGANIC COMPOUNDS IN SUMMA (TRADE NAME) POLISHED CANISTERS  

EPA Science Inventory

Six-liter volume SUMMA polished canisters were filled with air samples containing certain volatile organic compounds (VOCs) of environmental interest at concentrations at or below 2 ppbv. Samples were periodically withdrawn from the canisters and analyzed using capillary-column g...

414

Patterns in volatile organic compound emissions along a savanna-rainforest gradient in central Africa  

Microsoft Academic Search

In temperate regions the chemistry of the lower troposphere is known to be significantly affected by biogenic volatile organic compounds (VOCs) emitted by plants. The chemistry of the lower troposphere over the tropics, however, is poorly understood, in part because of the considerable uncertainties in VOC emissions from tropical ecosystems. Present global VOC models predict that base emissions of isoprene

L. F. Klinger; J. Greenberg; A. Guenther; G. Tyndall; P. Zimmerman; J.-M. Moutsambot; D. Kenfack

1998-01-01

415

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 ...

416

The tropospheric degradation of volatile organic compounds: a protocol for mechanism development  

Microsoft Academic Search

Kinetic and mechanistic data relevant to the tropospheric oxidation of volatile organic compounds (VOCs) are used to define a series of rules for the construction of detailed degradation schemes for use in numerical models. These rules are intended to apply to the treatment of a wide range of non-aromatic hydrocarbons and oxygenated and chlorinated VOCs, and are currently being used

Sandra M. Saunders; Michael J. Pilling

1997-01-01

417

Cadaveric volatile organic compounds released by decaying pig carcasses ( Sus domesticus L.) in different biotopes  

Microsoft Academic Search

Forensic entomology uses pig carcasses to surrogate human decomposition and to investigate the entomofaunal colonization. Insects communicate with their environment through the use of chemical mediators, which in the case of necrophagous insects, may consist in the cadaveric volatile organic compounds (VOCs) released by the corpse under decomposition. Previous studies have focused on cadaveric VOCs released from human corpses. Nevertheless,

J. Dekeirsschieter; F. J. Verheggen; M. Gohy; F. Hubrecht; L. Bourguignon; G. Lognay; E. Haubruge

2009-01-01

418

Heterogeneous Photocatalysis for Control of Volatile Organic Compounds in Indoor Air  

Microsoft Academic Search

Research results concerning the photocatalytic activity and selectivity of benzene are discussed. This compound, which represents one of an important class of volatile organic compounds found in indoor air, was oxidized in an annular photocatalytic reactor featuring a thin film of titanium dioxide and illuminated by a fluorescent black light. The gas phase products, carbon dioxide and carbon monoxide, were

William A. Jacoby; Daniel M Blake; John A. Penned; James E. Boulter; LeAnn M. Vargo; Marya C George; Suzanne K. Dolberg

1996-01-01

419

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 ...

420

Decomposition of Volatile Organic Compounds under Low-Energy Pulsed-Electron Beam Irradiation  

Microsoft Academic Search

Development of treatment system of gaseous pollutants including some toxic substances, such as nitrogen oxides (NOx) and volatile organic compounds (VOCs), is one of the important technological research subjects. It is well known that the non-thermal plasma processes using electrical discharge or electron beam are effective for the environmental pollutant removal. Especially, the electron beam can efficiently remove pollutant, because

Masato Watanabe; Asuna Fukamachi; Akitoshi Okino; Eiki Hotta; Kwang-Cheol Ko

2006-01-01

421

EPA ORD VOLATILE ORGANIC COMPOUNDS RECOVERY SEMINAR, OVERVIEW AND CONCLUDING REMARKS  

EPA Science Inventory

The USEPA conducted a seminar during 9/98 in Cincinnati, OH which focused on recovering Volatile Organic Compounds (VOCs). The seminar emphasized new/innovative VOC Recovery technologies as well as commercially available technologies and addressed applications in all environmenta...

422

Interlaboratory Study of a Test Method Measuring Total Volatile Organic Compound Content of Consumer Products  

Microsoft Academic Search

Consumer products are potentially significant sources of volatile organic compounds (VOCs), which are precursors to the formation of ozone in photochemical smog. To address the problem of ozone formation in ambient air, the U.S. Environmental Protection Agency (EPA) has been involved in the development of test methods for measuring the VOC content of consumer products. This paper describes results of

E. E. Rickman Jr; G. B. Howe; R. K. M. Jayanty; J. Kaye Whitfield

1997-01-01

423

Total exposure and risk assessment for drinking water contaminated with volatile organic compounds. Final report  

Microsoft Academic Search

A total-exposure and cancer-risk assessment was conducted on nine volatile organic compounds (VOCs) frequently found in contaminated drinking water. Routes of exposure considered in the analysis included ingestion, inhalation, and dermal uptake. A total of ten exposure scenarios were constructed, reflecting minimum and maximum likelihood exposures. The total exposure scenarios developed for VOCs, the most extensive reported to date, clearly

J. M. Clark; C. L. Fuller

1987-01-01

424

Separation and concentration of volatile organic contaminants by activated carbon cloth for cryogenic recovery  

Microsoft Academic Search

New air quality control regulations and economics are causing the development of new devices or the optimization of existing technologies for control of toxic emissions from industrial sources. Volatile organic contaminants (VOCs) account for 47%, and non-halogenated VOCs account for 36% of these toxic emissions. For these emissions, under the 1990 Clean Air Act Amendments (CAAA), the United States Environmental

M. Lordgooei; K. R. Carmichael; T. W. Kelly

1996-01-01

425

Natural Attenuation of Chlorinated Volatile Organic Compounds in a Freshwater Tidal Wetland, Aberdeen Proving Ground, Maryland.  

National Technical Information Service (NTIS)

During 1992-97, the U.S. Geological Survey investigated the natural attenuation of chlorinated volatile organic compounds (VOC's) in a contaminant plume that discharges from a sand aquifer to a freshwater tidal wetland along the West Branch Canal Creek at...

M. M. Lorah L. D. Olsen B. L. Smith M. A. Johnson W. B. Fleck

1997-01-01

426

Three-Dimensional Simulation of Volatile Organic Compound Mass Flux from the Vadose Zone to Groundwater  

Microsoft Academic Search

Low permeability layers of the vadose zone containing volatile organic compounds (VOCs) may persist as source zones for long time periods and may provide contamination to groundwater. At sites with low recharge rates, where vapor migration is the dominant transport process, the impact of vadose zone sources on groundwater may be difficult to assess. Typical assessment methods include one-dimensional numerical

Martinus Oostrom; Michael J. Truex; Guzel D. Tartakovsky; Thomas W. Wietsma

2010-01-01

427

VOC (VOLATILE ORGANIC COMPOUNDS) FUGITIVE EMISSION DATA - HIGH DENSITY POLYETHYLENE PROCESS UNIT  

EPA Science Inventory

The report gives data from a 10-month study of volatile organic compound (VOC) fugitive emissions from a high density polyethylene process unit. It gives statistics on leak frequency, leak occurrence, and leak recurrence, with a leak defined as having a screening value equal to o...

428

Determinants of exposure to volatile organic compounds in four Oklahoma cities  

Microsoft Academic Search

To begin to develop generalized models for estimating personal exposure to ambient air pollutants within diverse populations, the design of the Oklahoma Urban Air Toxics Study incorporated eight dichotomous macroenvironmental and household factors that were hypothesized to be potential determinants of exposure. Personal, indoor, and outdoor samples of volatile organic compounds (VOCs) were collected over 24-h monitoring periods in 42

Margaret L Phillips; Nurtan A Esmen; Thomas A Hall; Robert Lynch

2005-01-01

429

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...

430

ASSESSING THE PERFORMANCE OF AMBIENT AIR SAMPLERS FOR VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

Performance audit results of two different ambient air monitoring projects for volatile organic compounds (VOC's) are presented. An NBS traceable gas cylinder containing several VOC's in dry nitrogen at parts per billion (ppb) concentration levels was used at the field sampling s...

431

Oxidation of diesel-generated volatile organic compounds in the selective catalytic reduction process  

Microsoft Academic Search

The main part of the VOCs (volatile organic compounds) contained in diesel exhaust (80%) is oxidized to CO and CO over an SCR (selective catalytic reduction) catalyst. CO is the major product of this oxidation, representing about 50--70% of the formed products (CO + CO). This preferential formation of CO leads to a pronounced increase of CO emissions when an

M. Koebel; M. Elsener

1998-01-01

432

Volatile organic chemical emissions from structural insulated panel (SIP) materials and implications for indoor air quality  

SciTech Connect

The emissions of volatile organic compounds (VOCs) from structural insulated panel (SIP) materials were investigated. Specimens of newly produced SIPs and associated panel adhesives were obtained from two relatively large manufacturers. Additionally, specimens of the oriented strand board (OSB) used as the inner and outer sheathing and the extruded polystyrene core for the SIP were obtained from one manufacturer. Using small-scale chambers, emissions of formaldehyde, acetaldehyde, acetic acid and other VOCs from SIPs, OSB and polystyrene were measured over a period of four months and from the adhesives over two months. SIP specimens overlaid by gypsum board panels were also tested over four months. The predominant VOCs emitted by the SIPs included acetic acid, pentanal, hexanal and styrene. The emissions of formaldehyde and acetaldehyde were relatively low. Acetic acid and the aldehydes derived from the OSB, while styrene derived from the polystyrene. One of the SIPs emitted toluene and methyl acetate. The adhesives primarily emitted a mixture of hydrocarbons. The emission rates of most VOCs from the SIP/gypsum board assemblies were approximately the same or higher than their respective emission rates from the unfinished SIPs. Modeling using VOC emission factors obtained for the SIP/gypsum board assemblies demonstrated the potential for SIP materials to degrade indoor air quality in houses. A field study to investigate VOC concentrations and emission rates in SIP houses relative to closely matched conventionally constructed houses is necessary to determine the actual impacts of SIPs. If significant impacts are observed, to it may be desirable to develop control measures to reduce the emissions of VOCs from SIPs, such as the substitution of lower emitting materials or the use of vapor diffusion barriers.

Hodgson, Alfred T.

2003-09-01

433

Contribution of non methane organic volatiles exchange to the carbon budget of isoprene and monoterpene emitting plant species  

Microsoft Academic Search

Compared to the aerosol fraction, most of the organic carbon present in the atmosphere is found in form of volatile or semivolatile compounds. Vegetation was identified being the major source of these organic volatiles, releasing carbon at the same order of magnitude as the global net biome productivity (NBP). To achieve an estimate of plants carbon exchange, including the emission

T. Dindorf; U. Kuhn; C. Ammann; A. Neftel; C. Tritsch; P. Ciccioli; R. Koppmann; J. Kesselmeier

2003-01-01

434

Effects of volatile organic compounds, damp, and other environmental exposures in the home on wheezing illness in children  

Microsoft Academic Search

Background: The effects of indoor exposure to volatile organic compounds (VOCs), including formaldehyde, on respiratory health are not clearly understood. The aim of this study was to determine the independent effects of VOCs and other common environmental exposures in the home on the risk and severity of persistent wheezing illness in children.Methods: Total volatile organic compounds, formaldehyde, nitrogen dioxide, damp

A J Venn; M Cooper; M Antoniak; C Laughlin; J Britton; S A Lewis

2003-01-01

435

RECEPTOR MODEL COMPARISONS AND WIND DIRECTION ANALYSES OF VOLATILE ORGANIC COMPOUNDS AND SUBMICROMETER PARTICLES IN AN ARID, BINATIONAL, URBAN AIRSHED  

EPA Science Inventory

The relationship between continuous measurements of volatile organic compounds sources and particle number was evaluated at a Photochemical Assessment Monitoring Station Network (PAMS) site located near the U.S.-Mexico Border in central El Paso, TX. Sources of volatile organic...

436

The use of naturally generated volatile fatty acids for herbicide removal via denitrification  

Microsoft Academic Search

This research focuses on the removal of 2, 4-D via denitrification, with a particular emphasis on the effect of adding naturally generated volatile fatty acids (VFAs) as a carbon source. These VFAs had been produced from an acid-phase anaerobic digester (mean VFA concentration of 3153 801 mg\\/L [as acetic acid]). The first step involved developing 2, 4-D degrading bacteria

Xuan He; David G. Wareham

2009-01-01

437

(Semi)volatile Organic Compounds and Microbiological Entities in Snow during OASIS Barrow 2009  

NASA Astrophysics Data System (ADS)

Snow has recently been shown to be an active medium for the deposition of (semi-)volatile (bio)organic compounds. We collected surface snow samples during the OASIS Barrow campaign in March 2009 for analysis of semi-volatile organic compounds using solid phase microextraction and gas chromatography with mass spectrometric detection (SPME-GC/MS). Additional grab samples were taken for analysis of non-methane hydrocarbons in air. Moreover we analyzed for microbial species in air and snow. Identifed organic compounds covered a wide range of functionalities and molecular weights, including oxygenated reactive speces such as aldehydes (e.g., hexanal to decanal), alcohols (e.g., hexanol, octanol) and aromatic species (e.g., methyl- and ethylbenzenes). Quantification data for selected aromatic species are presented with concentrations in the upper ng/L range. We will present our preliminary data on microbiological species, and will discuss the potential implications of the results for organic snow chemistry.

Kos, G.; Nafissa, A.; Lutchman, D.; Mortazavi, R.; Ariya, P.

2009-12-01

438

Health Effects of a Mixture of Indoor Air Volatile Organics, Their Ozone Oxidation Products, and Stress  

PubMed Central

In our present study we tested the health effects among women of controlled exposures to volatile organic compounds (VOCs), with and without ozone (O3), and psychological stress. Each subject was exposed to the following three conditions at 1-week intervals (within-subject factor): VOCs (26 mg/m3), VOCs + O3 (26 mg/m3 + 40 ppb), and ambient air with a 1-min spike of VOCs (2.5 mg/m3). As a between-subjects factor, half the subjects were randomly assigned to perform a stressor. Subjects were 130 healthy women (mean age, 27.2 years; mean education, 15.2 years). Health effects measured before, during, and after each 140-min exposure included symptoms, neurobehavioral performance, salivary cortisol, and lung function. Mixing VOCs with O3 was shown to produce irritating compounds including aldehydes, hydrogen peroxide, organic acids, secondary organic aerosols, and ultrafine particles (particulate matter with aerodynamic diameter < 0.1 ?m). Exposure to VOCs with and without O3 did not result in significant subjective or objective health effects. Psychological stress significantly increased salivary cortisol and symptoms of anxiety regardless of exposure condition. Neither lung function nor neurobehavioral performance was compromised by exposure to VOCs or VOCs + O3. Although numerous epidemiologic studies suggest that symptoms are significantly increased among workers in buildings with poor ventilation and mixtures of VOCs, our acute exposure study was not consistent with these epidemiologic findings. Stress appears to be a more significant factor than chemical exposures in affecting some of the health end points measured in our present study.

Fiedler, Nancy; Laumbach, Robert; Kelly-McNeil, Kathie; Lioy, Paul; Fan, Zhi-Hua; Zhang, Junfeng; Ottenweller, John; Ohman-Strickland, Pamela; Kipen, Howard

2005-01-01

439

Volatile organic compound (VOC) species data manual. Second edition  

SciTech Connect

This document contains tables of potential emissions of organic compounds for selected source categories. The species profile table format has been organized to be particularly useful in preparation of emission inventory inputs to photochemical modeling. Accompanying each VOC profile table is a brief narrative that describes process, emissions, controls, and basis of source report and data quantification. The chemical classifications include paraffin, olefin, aromatic, carbonyl (aldehydes and ketones), methane, non-reactive other than methane, and miscellaneous. Data confidence levels for each profile table have been assigned. Reports, published data, and names and titles of personal contacts are referenced for each source category.

Not Available

1980-07-01

440

Reactions of Volatile Furandiones, Aldehydes and Water Vapor in Secondary Organic Aerosol Formation and in Gas Chromatography Analysis  

NASA Astrophysics Data System (ADS)

Volatile furandiones and aldehydes are important atmospheric oxidation products of simple aromatic compounds found in gasoline. A mechanism of secondary organic aerosol formation by furandiones was identified using particle chamber observations and FTIR measurements of model condensed phases. Growth of inorganic seed aerosol was monitored by scanning mobility particle sizing in the presence of humidity and high concentrations of 2,5-furandione (maleic anhydride), 3-methyl-2,5-furandione (citraconic anhydride), benzaldehyde, and trans-cinnamaldehyde. Particle growth began when the gas-phase saturation level of each organic compound (relative to its pure liquid) and water vapor, when summed together, reached a threshold near one. This threshold implies that equilibrium is established between the gas phase and a newly formed, mixed condensed phase containing both organic compounds and water. This equilibrium appears to be governed by Raoult's Law, where the vapor pressure of each component is reduced proportionally to its mole fraction in the condensed phase. However, bulk liquid phase experiments showed that these organics are immiscible with water at the mole fractions expected in the particle phase in our chamber experiments. Thus, non-reactive condensation of these compounds into a mixed organic / aqueous phase is ruled out. Instead, we show that reactions between furandiones and water produce unusually strong dicarboxylic acids: cis-methylbutenedioic acid (citraconic acid) and cis-butenedioic acid (maleic acid). Bulk phase pH microprobe and FTIR attenuated total reflectance measurements demonstrated that an aqueous phase is rapidly acidified during exposure to furandiones. In addition, the presence of furandiones also greatly increased benzaldehyde solubility. This solubility increase has two causes. First, the entry of maleate (or methylmaleate) ions into the water layer lowers the polarity of the phase. Second, the increase in acidity may enhance reactivity at the aldehyde functional group. Thus the uptake of both furandiones and aldehydes onto particles in the presence of humidity appears to be reaction-dependent. When subjected to normal GC injector temperatures, the cis-butenedioic acids produced in these reactions recyclize back to furandiones with much greater ease than similar alkanedioic or trans-alkenedioic acids. This production of volatile compounds during GC analysis could cause large artifacts in gas / particle phase distribution measurements if chemical derivatization techniques are not employed.

Koehler, C. A.; Fillo, J. D.; Ries, K. A.; Sanchez, J. T.; de Haan, D. O.

2004-05-01

441

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

USGS Publications Warehouse

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.

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

1985-01-01

442

Monitoring Volatile Organic Tank Waste Using Cermet Microsensors  

Microsoft Academic Search

Presently, very few inexpensive technologies exist in the marketplace that can determine the contents of tank waste or monitor the chemistry of tank constituents in near-real time. The research addressed this problem by developing and assessing ceramic-metallic based microsensors for determining the constituents of a liquid organic storage tank by examining the gases in the headspace of the tank. Overall,

Edward G. Gatliff; Laura R. Skubal; Michael C. Vogt

2006-01-01

443

Development of technology performance specifications for volatile organic compounds  

Microsoft Academic Search

The Office of Technology Development (OTD) within the Office of Environmental Restoration and Waste Management of the Department of Energy has a mission to deliver needed and usable technologies to its customers. The primary customers are individuals and organizations performing environmental characterization and remediation, waste cleanup, and pollution prevention at DOE sites. DOE faces a monumental task in cleaning up

C. Purdy; W. E. Schutte; M. D. Erickson; S. C. Carpenter; P. V. Doskey; P. C. Lindahl; A. D. Pflug

1993-01-01

444

MULTICOMPONENT ADSORPTION OF VOLATILE ORGANIC CHEMICALS ONTO GRANULAR ACTIVATED CARBON  

EPA Science Inventory

A technique has been developed to predict the fixed-bed removal of known SOCs in background mixtures of unknown composition. In addition, this technique was used to relate the removal of important SOCs to nonspecific measures of contamination such as total organic halogen (TOX). ...

445

REVERSE OSMOSIS TREATMENT TO CONTROL INORGANIC AND VOLATILE ORGANIC CONTAMINATION  

EPA Science Inventory

Because of the versatility of reverse osmosis for removing a wide range of contaminants, U.S. EPA (Drinking Water Research Division) has been conducting laboratory and field studies to determine its effectiveness on specific inorganic and organic contaminants of concern to the wa...

446

VOLATILE ORGANIC CHEMICALS IN 10 PUBLIC-ACCESS BUILDINGS  

EPA Science Inventory

The U.S. EPA carried out studies of indoor air quality in 10 buildings. Qualitative analysis identified over 200 aromatics, halogens, esters, alcohols, phenols, ethers, ketones, aldehydes, and epoxides, in addition to several hundred aliphatic hydrocarbons. The total organic load...

447

Volatile organic compound emissions from elephant grass and bamboo cultivars used as potential bioethanol crop  

NASA Astrophysics Data System (ADS)

Volatile organic compound (VOC) emissions from elephant grass (Miscanthus gigantus) and black bamboo (Phyllostachys nigra) were measured online in semi-field chamber and plant enclosure experiments during growth and harvest using proton-transfer reaction mass spectrometry (PTR-MS), proton-transfer reaction ion-trap mass spectrometry (PIT-MS) and gas chromatography-mass spectrometry (GC-MS). Both cultivars are being considered for second-generation biofuel production. Before this study, no information was available on their yearly VOC emissions. This exploratory investigation shows that black bamboo is a strong isoprene emitter (daytime 28,516 ng gdwt-1 h-1) and has larger VOC emissions, especially for wound compounds from the hexanal and hexenal families, than elephant grass. Daytime emissions of methanol, acetaldehyde, acetone + propanal and acetic acid of black bamboo were 618, 249, 351, and 1034 ng gdwt-1 h-1, respectively. In addition, it is observed that elephant grass VOC emissions after harvesting strongly depend on the seasonal stage. Not taking VOC emission variations throughout the season for annual and perennial species into account, may lead to an overestimation of the impact on local air quality in dry periods. In addition, our data suggest that the use of perennial grasses for extensive growing for biofuel production have lower emissions than woody species, which might be important for regional atmospheric chemistry.

Crespo, E.; Graus, M.; Gilman, J. B.; Lerner, B. M.; Fall, R.; Harren, F. J. M.; Warneke, C.

2013-02-01

448

Removal of volatile organic compounds by heterogeneous ozonation on microporous synthetic alumina silicate.  

PubMed

A hybrid process combining adsorption and ozonation was examined as an alternative treatment for odorous volatile organic compounds (VOCs). Methyl ethyl ketone (MEK) was chosen to study the influence of operating parameters. Two synthetic aluminosilicates (faujasite-Y and ZSM-5) were tested for adsorption and reactivity with ozone. The adsorption equilibrium measurement on both adsorbents showed that adsorption performance depends on temperature but is not sensitive to relative humidity, due to the hydrophobic properties of the materials. Adsorbed VOCs were oxidized at low temperature when ozonated flow was sent to the reactor. Regeneration of the fixed bed was achieved at the same time, releasing mainly CO(2) and H(2)O. Intermediates of oxidation, such as 2,3-butanedione and acetic acid, were identified, leading to incomplete mineralization. The influence of concentration and humidity are discussed. Four successive cycles were tested: after the first adsorption/ozonation cycle, the adsorption efficiency was not affected during subsequent cycles. These results show that the same sample of adsorbent can be used in the treatment process for a long time. Ozonation regeneration is a promising process for VOC removal. PMID:22925878

Brodu, Nicolas; Zaitan, Hicham; Manero, Marie-Hlne; Pic, Jean-Stphane

2012-01-01

449

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

PubMed

Law enforcement agencies frequently use canines trained to detect the odor of human decomposition to aid in determining the location of clandestine burials and human remains deposited or scattered on the surface. However, few studies attempt to identify the specific volatile organic compounds (VOCs) that elicit an appropriate response from victim recovery (VR) canines. Solid-phase microextraction (SPME) was combined with gas chromatography-mass spectrometry (GC-MS) to identify the VOCs released into the headspace associated with 14 separate tissue samples of human remains previously used for VR canine training. The headspace was found to contain various classes of VOCs, including acids, alcohols, aldehydes, halogens, aromatic hydrocarbons, ketones, and sulfides. Analysis of the data indicates that the VOCs associated with human decomposition share similarities across regions of the body and across types of tissue. However, sufficient differences exist to warrant VR canine testing to identify potential mimic odor chemical profiles that can be used as training aids. The resulting data will assist in the identification of the most suitable mixture and relative concentrations of VOCs to appropriately train VR canines. PMID:19203852

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

2009-02-08

450

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

Microsoft Academic Search

Volatile organic compounds (VOC) and soot particles have been determined in a Diesels exhaust gas. A new sampling method allowed the measurement of emissions of organic compounds (C1 to C20) in a gas chromatogram at a detection limit of ca. 0.2 mg\\/m3. Particles were collected with a filter bed of ceramic particles and characterized by temperature programmed desorption (TPD) and

Hans Schulz; Gilberto Bandeira De Melo; Farid Ousmanov

1999-01-01

451

Cloud nucleating activities of water-soluble semi-volatile organic compounds  

NASA Astrophysics Data System (ADS)

The activities of organic compounds in serving as cloud condensation nuclei (CCN) have been extensively studied due to their potential impact on cloud formation. However, a number of experimental challenges remain. This study aims at addressing uncertainties often faced in CCN studies: 1) incomplete drying of particles, 2) evaporation of volatile organics from particles, 3) phase change during the drying process. The feasibility of performing CCN activity measurements using wet aerosols is discussed.

Nakao, Shunsuke; Kreidenweis, Sonia

2013-05-01

452

Field measurement of nickel sediment toxicity: role of acid volatile sulfide.  

PubMed

A field experiment was performed in four freshwater systems to assess the effects of Ni on the benthic macroinvertebrate communities. Sediments were collected from the sites (in Belgium, Germany, and Italy), spiked with Ni, and returned to the respective field sites. The colonization process of the benthic communities was monitored during a nine-month period. Nickel effect on the benthos was also assessed in the context of equilibrium partitioning model based on acid volatile sulfides (AVS) and simultaneously extracted metals (SEM). Benthic communities were not affected at (SEM?-?AVS) ? 0.4?mol/g, (SEM?-?AVS)/fraction of organic carbon (f(OC)) < 21?mol/g organic carbon (OC). Sediments with (SEM?-?AVS)?>?2?mol/g, (SEM?-?AVS)/f(OC)?>?700?mol/g OC resulted in clear adverse effects. Uncertainty about the presence and absence of Ni toxicity occurred at (SEM?-?AVS) and (SEM?-?AVS)/f(OC) between 0.4 to 2?mol/g and 21 to 700?mol/g OC, respectively. The results of our study also indicate that when applying the SEM:AVS concept for predicting metal toxicity in the field study, stressors other than sediment characteristics (e.g., sorption capacity), such as environmental disturbances, should be considered, and the results should be carefully interpreted. PMID:20853448

Nguyen, Lien T H; Burton, G Allen; Schlekat, Chris E; Janssen, Colin R

2011-01-01

453

Acid volatile sulfide and simultaneously extracted metals in superficial sediments from Baihua Lake, China  

NASA Astrophysics Data System (ADS)

The bioavailability of five divalent cationic heavy metals (Pb, Cd, Cu, Zn and Ni) in 10 superficial sediment samples from Baihua Lake was assessed based on the molar ratio of simultaneously extracted metals (SEMs) to acid volatile sulfide (AVS). Atomic absorption spectrometry (AAS) and X-ray powder diffraction (XRD) were used to determine the heavy metal concentrations and examine the mineralogy of the crystalline phases, respectively. The AVS loadings in sediments from Baihua Lake ranged from 64.30 to 350.08 ?mol/g (dry weight). The corresponding SEM levels for the sampling sites varied from 1.770 to 14.660 ?mol/g. The molar ratio of SEMs to AVS ranged from 0.014 to 0.084 with a mean value of 0.034. The XRD analysis also confirmed the presence of some metal sulfides in sediments from Baihua Lake. The SEMs/AVS ratios for all sampling sites were significantly lower than 1.0, indicating that AVS in the sediments was sufficient to bind the five heavy metals; thus, these heavy metals are currently not significantly bioavailable to benthic organisms. Comparing the SEMs results to published guideline values for metal toxicity to benthic organisms in sediments, however, suggests that Zn and Ni pose a risk at some sampling locations in Baihua Lake.

Zhang, Jiping; Hu, Jiwei; Huang, Xianfei; Shen, Wei; Jin, Mei; Fu, Liya; Jin, Xiaofei

2013-09-01

454

Combined volatility and mass spectrometric measurements of biogenic secondary organic aerosol  

NASA Astrophysics Data System (ADS)

The volatility of secondary organic aerosol (SOA) from the oxidation of mixtures of biogenic Volatile Organic Compounds (VOC) has been investigated in the SAPHIR facility in Forschungszentrum Jlich, Germany, by using a Volatility Tandem Differential Mobility Analyser (VTDMA). The standard VTDMA setup comprises three main parts: 1) An initial DMA, where a nearly monodisperse size fraction of the aerosol particles is selected (typically 100 or 150 nm), 2) the oven unit, i.e. four ovens in parallel where each oven includes a heating and adsorption section where the evaporation and adsorption of the volatile fraction occurs and 3) a final SMPS (Scanning Mobility Particle Sizer) system where the residual particle number distribution is measured. For this measurement campaign the set-up also contained a Quadrupole Aerosol Mass Spectrometer (Aerodyne QAMS). The temperature of the ovens can be varied between 298 and well above 573 K. In parallel to the final SMPS the AMS was used for chemical composition and density measurements. When the system was dedicated for AMS measurements the initial DMA was bypassed to improve the aerosol concentration. However, the produced SOA has a narrow size distribution still making it possible to follow small changes in the aerosol peak diameter. A general feature of the thermo-denuder system is that a less volatile SOA gives a larger residual particle size distribution compared to more volatile SOA. The experiments conducted were based on photochemical oxidation of selected terpene mixtures. A reference boreal mixture of terpenes, consisting of ?-pinene, β-pinene, limonene, ^-3-carene, and ocimene was used as base case. Secondary organic aerosol was formed from the precursor compounds by reaction with O3/H2O/OH in SAPHIR on the first day. The particles were kept in the chamber for up to two further days and were exposed to natural sunlight and OH radicals to initiate close to natural chemical ageing. The VTDMA results show that SOA becomes less volatile during ageing and this ageing was further enhanced when the mixtures were exposed to sunlight. The volatility was also affected by changes in the terpene mixtures. With the AMS we measured mass spectra of the organic aerosol particles at a reference temperature of 298 K and two additional elevated temperatures. Size distributions of the particles were obtained from the particle-time-of-flight mode of the AMS at sixteen representative m/z values. The residual total mass measured at the elevated oven temperatures was related to the total mass at the reference temperature to obtain the mass fraction remaining (MFR), which is higher for less volatile SOA. In agreement with the decreasing volatility during aging measured with the VTDMA, the MFR increases with time. An effective density of the particles was calculated comparing the mode position of the size distributions measured with the AMS and the SMPS. The effective density increases with ongoing photochemical ageing. In addition, the density of the low volatile residual particles that passed a high-temperature oven is higher than the density of particles at reference temperature. In order to investigate if the observed changes in density and volatility can be attributed to changes of the chemical composition of the particles, the mass spectra obtained at different oven temperatures and different chemical age were compared. We found that the ratio of heavy fragments (m/z > 90) increases with higher temperatures. Furthermore the fraction of the CO2+-fragment at m/z 44 to the total mass increases during the ageing process.

Emanuelsson, E.; Buchholz, A.; Hallquist, M.; Kiendler-Scharr, A.; Mentel, T.; Spindler, C.

2009-04-01

455

Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory  

NASA Astrophysics Data System (ADS)

Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic.

Ng, Tse Nga; Schwartz, David E.; Lavery, Leah L.; Whiting, Gregory L.; Russo, Beverly; Krusor, Brent; Veres, Janos; Brms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

2012-08-01

456

Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory.  

PubMed

Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic. PMID:22900143

Ng, Tse Nga; Schwartz, David E; Lavery, Leah L; Whiting, Gregory L; Russo, Beverly; Krusor, Brent; Veres, Janos; Brms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

2012-08-16

457

Modulation of volatile organic compound formation in the Mycodiesel-producing endophyte Hypoxylon sp. CI-4.  

PubMed

An endophytic Hypoxylon sp. (strain CI-4) producing a wide spectrum of volatile organic compounds (VOCs), including 1,8-cineole, 1-methyl-1,4-cyclohexadiene and cyclohexane, 1,2,4-tris(methylene), was selected as a candidate for the modulation of VOC production. This was done in order to learn if the production of these and other VOCs can be affected by using agents that may modulate the epigenetics of the fungus. Many of the VOCs made by this organism are of interest because of their high energy densities and thus the potential they might have as Mycodiesel fuels. Strain CI-4 was exposed to the epigenetic modulators suberoylanilide hydroxamic acid (SAHA, a histone deacetylase) and 5-azacytidine (AZA, a DNA methyltransferase inhibitor). After these treatments the organism displayed striking cultural changes, including variations in pigmentation, growth rates and odour, in addition to significant differences in the bioactivities of the VOCs. The resulting variants were designated CI4-B, CI4-AZA and CI4-SAHA. GC/MS analyses of the VOCs produced by the variants showed considerable variation, with the emergence of several compounds not previously observed in the wild-type, particularly an array of tentatively identified terpenes such as ?-thujene, sabinene, ?-terpinene, ?-terpinolene and ?-selinene, in addition to several primary and secondary alkanes, alkenes, organic acids and derivatives of benzene. Proton transfer reaction mass spectroscopic analyses showed a marked increase in the ratio of ethanol (mass 47) to the total mass of all other ionizable VOCs, from ~0.6 in the untreated strain CI-4 to ~0.8 in CI-4 grown in the presence of AZA. Strain CI4-B was created by exposure of the fungus to 100 M SAHA; upon removal of the epigenetic modulator from the culture medium, it did not revert to the wild-type phenotype. Results of this study have implications for understanding why there may be a wide range of VOCs found in various isolates of this fungus in nature. PMID:22096148

Ul-Hassan, Syed Riyaz; Strobel, Gary A; Booth, Eric; Knighton, Berk; Floerchinger, Cody; Sears, Joe

2011-11-17

458

Attraction of the gypsy moth to volatile organic compounds (VOCs) of damaged Dahurian larch.  

PubMed

Olfactory responses of the gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae), a major defoliator of deciduous trees, were examined in Inner Mongolia, China. We studied whether the gypsy moth adults are attracted by the major volatile organic compounds (VOCs) of damaged Larix gmelinii (Dahurian larch) foliage and compared the attractiveness of the plant volatiles with that of the synthetic sex pheromone. Our results indicated that the VOCs of the Dahurian larch were effective in attracting gypsy moth males especially during the peak flight period. The VOCs also attracted moths significantly better than the sex pheromone of the moth. Our study is the first trial to show the responses of adult gypsy moths to volatile compounds emitted from a host plant. Electroantennogram responses of L. gmelinii volatiles on gypsy moths supported our field observations. A synergistic effect between host plant volatiles and sex pheromone was also obvious, and both can be jointly applied as a new attractant method or population management strategy of the gypsy moth. PMID:23016284

Li, Jing; Valimaki, Sanna; Shi, Juan; Zong, Shixiang; Luo, Youqing; Heliovaara, Kari

459

Human exposures to volatile halogenated organic chemicals in indoor and outdoor air.  

PubMed

Volatile halogenated organic chemicals are found in indoor and outdoor air, often at concentrations substantially above those in remote, unpopulated areas. The outdoor ambient concentrations vary considerably among sampling stations throughout the United States, as well as diurnally and daily. The vapor pressures and air-water equilibrium (Henry's Law) constants of these chemicals influence considerably the likely relative human exposures for the air and water routes. Volatilization of chemicals from indoor uses of water can be a substantial source of exposure, as shown for radon-222. Measurements of air concentrations of trichloroethylene (TCE) in showers using TCE contaminated groundwater show increases with time to as high as one-third of occupational threshold limit values. Using a scaled down experimental shower, such volatilization and subsequent decay in air was also demonstrated. Using a simplified indoor air model and assuming complete volatilization from a full range of typical water uses within the home, calculations indicate that the expected air inhalation exposures can be substantially higher than those from ingestion of these chemicals in drinking water. Although the regulation of toxic chemicals in potable water supplies has focused traditionally on direct ingestion, the volatilization and inhalation from other much greater volume indoor uses of water should be considered as well. PMID:4085436

Andelman, J B

1985-10-01

460

Human exposures to volatile halogenated organic chemicals in indoor and outdoor air.  

PubMed Central

Volatile halogenated organic chemicals are found in indoor and outdoor air, often at concentrations substantially above those in remote, unpopulated areas. The outdoor ambient concentrations vary considerably among sampling stations throughout the United States, as well as diurnally and daily. The vapor pressures and air-water equilibrium (Henry's Law) constants of these chemicals influence considerably the likely relative human exposures for the air and water routes. Volatilization of chemicals from indoor uses of water can be a substantial source of exposure, as shown for radon-222. Measurements of air concentrations of trichloroethylene (TCE) in showers using TCE contaminated groundwater show increases with time to as high as one-third of occupational threshold limit values. Using a scaled down experimental shower, such volatilization and subsequent decay in air was also demonstrated. Using a simplified indoor air model and assuming complete volatilization from a full range of typical water uses within the home, calculations indicate that the expected air inhalation exposures can be substantially higher than those from ingestion of these chemicals in drinking water. Although the regulation of toxic chemicals in potable water supplies has focused traditionally on direct ingestion, the volatilization and inhalation from other much greater volume indoor uses of water should be considered as well.

Andelman, J B

1985-01-01

461

Volatility and hygroscopicity of aging secondary organic aerosol in a smog chamber  

NASA Astrophysics Data System (ADS)

The evolution of secondary organic aerosols (SOA) during (photo-)chemical aging processes was investigated in a smog chamber. Fresh SOA from ozonolysis of 10 to 40 ppb ?-pinene was formed followed by aging with OH radicals. The particles' volatility and hygroscopicity (expressed as volume fraction remaining (VFR) and hygroscopicity parameter ?) were measured in parallel with a volatility and hygroscopicity tandem differential mobility analyzer (V/H-TDMA). An aerosol mass spectrometer (AMS) was used for the chemical characterization of the aerosol. These measurements were used as sensitive parameters to reveal the mechanisms possibly responsible for the changes in the SOA composition during aging. A change of VFR and/or ? during processing of atmospheric aerosols may occur either by addition of SOA mass (by condensation) or by a change of SOA composition leading to different aerosol properties. The latter may occur either by heterogeneous reactions on the surface of the SOA particles, by condensed phase reactions like oligomerization or by an evaporation - gas-phase oxidation - recondensation cycle. The condensation mechanism showed to be dominant when there is a substantial change in the aerosol mass by addition of new molecules to the aerosol phase with time. Experiments could be divided into four periods based on the temporal evolution (qualitative changes) of VFR, ? and organic mass: O3 induced condensation, ripening, and OH induced chemical aging first with substantial mass gain and then without significant mass gain. During the O3 induced condensation the particles' volatility decreased (increasing VFR) while the hygroscopicity increased. Thereafter, in the course of ripening volatility continued to decrease, but hygroscopicity stayed roughly constant. After exposing the SOA to OH radicals an OH induced chemical aging with substantial mass gain started resulting in the production of at least 50 % more SOA mass. This new SOA mass was highly volatile and oxidized. This period was then followed by further OH induced chemical aging without significant mass gain leading to a decrease of volatility while hygroscopicity and SOA mass stayed roughly constant.

Tritscher, T.; Dommen, J.; Decarlo, P. F.; Gysel, M.; Barmet, P. B.; Praplan, A. P.; Weingartner, E.; Prvt, A. S. H.; Riipinen, I.; Donahue, N. M.; Baltensperger, U.

2011-11-01

462

Removal of volatile fatty acids (VFA) by microbial fuel cell with aluminum electrode and microbial community identification with 16S rRNA sequence  

Microsoft Academic Search

Removal of volatile fatty acids in anaerobic digestion of organic wastes can accelerate eventual decomposition of organic\\u000a wastes to CO2 and H2O using a recovery of electric energy by a microbial fuel cell. The fuel cell anode chamber was a 10 cm (I.D.)20 cm long\\u000a cylindrical Plexiglass having an ion ceramic cylinder separator (I.D.10 mm, O.D.12 mm, 0.3 ?m average

Chang Moon Jeong; Jin Dal Rae Choi; Yeonghee Ahn; Ho Nam Chang

2008-01-01

463

An Investigation of Fecal Volatile Organic Metabolites in Irritable Bowel Syndrome  

PubMed Central

Diagnosing irritable bowel syndrome (IBS) can be a challenge; many clinicians resort to invasive investigations in order to rule out other diseases and reassure their patients. Volatile organic metabolites (VOMs) are emitted from feces; understanding changes in the patterns of these VOMs could aid our understanding of the etiology of the disease and the development of biomarkers, which can assist in the diagnosis of IBS. We report the first comprehensive study of the fecal VOMs patterns in patients with diarrhea-predominant IBS (IBS-D), active Crohn's disease (CD), ulcerative colitis (UC) and healthy controls. 30 patients with IBS-D, 62 with CD, 48 with UC and 109 healthy controls were studied. Diagnosis of IBS-D was made using the Manning criteria and all patients with CD and UC met endoscopic, histologic and/or radiologic criteria. Fecal VOMs were extracted by solid phase microextraction (SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). 240 VOMs were identified. Univariate analysis showed that esters of short chain fatty acids, cyclohexanecarboxylic acid and its ester derivatives were associated with IBS-D (p<0.05), while aldehydes were more abundant in IBD (p<0.05). A predictive model, developed by multivariate analysis, separated IBS-D from active CD, UC and healthy controls with a sensitivity of 94%, 96% and 90%; and a specificity of 82%, 80% and 80% respectively (p<0.05). The understanding of the derivation of these VOMs may cast light on the etiology of IBS-D and IBD. These data show that fecal VOMs analyses could contribute to the diagnosis of IBS-D, for which there is no laboratory test, as well as IBD.

Ahmed, Iftikhar; Greenwood, Rosemary; Costello, Ben de Lacy; Ratcliffe, Norman M.; Probert, Chris S.

2013-01-01

464

Nucleation and growth of atmospheric particles: Contribution of ion-mediated nucleation and role of low volatile organics condensation  

NASA Astrophysics Data System (ADS)

Formation and subsequent growth of secondary particles is an important source of atmospheric aerosol and contributes significantly to climate effective aerosols. It is now generally accepted that H2SO4 and ions are involved in the nucleation process while low volatile organic gases (LV-SOG) and H2SO4 are involved in the growth process, although the relative contribution of ion versus neutral nucleation and possible involvement of species other than sulfuric acid in the nucleation process remain controversial. Here we study the particle formation and growth processes in the troposphere using a global chemical transport model (GEOS-Chem) with an advanced particle microphysics (APM) module incorporated. The widely used 2-product secondary organic aerosol (SOA) formation model has been extended to take into account the volatility changes of secondary organic gases (SOGs) arising from the aging process. In addition to semi-volatile SOG (SV-SOG) and medium-volatile SOG (MV-SOG), we add a third component representing low-volatile SOG (LV-SOG) and design a scheme to transfer MV-SOG to SV-SOG and SV-SOG to LV-SOG associated with oxidation aging. The co-condensation of H2SO4 and LV-SOG on particles is explicitly simulated in GEOS-Chem + APM. Our predicted LV-SOG concentrations are generally a factor of ~2-20 higher than those of [H2SO4], and LV-SOG condensation significantly enhances particle growth rates and SOA mass over many parts of the continents. We show that ion-mediated nucleation appears to be able to capture within a factor of ~ 2 the particle number concentrations measured around the globe. Comparisons of the simulated and observed evolution of particle size distributions at selected sites clearly show that LV-SOG condensation is critical in order to bring the simulations closer to the observations. Ion-mediated nucleation and LV-SOG condensation substantially increase the concentration of cloud condensation nuclei. The ability of GEOS-Chem +APM in explaining the seasonal and the diurnal variations of particle size distributions and number concentrations at a number of locations will be assessed and implications will be discussed.

Yu, F.; Luo, G.

2010-12-01

465

Effect of Volatile Fatty Acid Infusion on Development of the Rumen Epithelium in Neonatal Sheep1  

Microsoft Academic Search

The purpose of this study was to determine whether the continuous intraruminal infusion of cal- culated physiological concentrations of volatile fatty acids (VFA) stimulated the metabolic development of the neonatal rumen. Eight 1-wk-old lambs were as- signed to one of three treatments: saline infusion (three lambs), VFA infusion (three lambs), or no infusion (two lambs). Rumen catheters were surgi- cally

B. W. Jesse

1997-01-01

466

Characteristics of Volatile Fatty Acid and Oxidation Reduction Potential for Treating Municipal Wastewater in Modified EGSB  

Microsoft Academic Search

The traditional Expanded Granular Sludge Bed (EGSB) reactor was modified to treating municipal wastewater. The characteristics of Oxidation Reduction Potential (ORP) and Volatile Fatty Acid (VFA) concentration of effluent was studied to judge to the operation condition of anaerobic degradation process. The characteristics of ORP and VFA for treating municipal wastewater was studied in modified Expanded Granular Sludge Bed (EGSB).

Ma Limin; Sun Xiaojing; Ma Xiujuan

2009-01-01

467

VOLATILE FATTY ACIDS AND ESSENTIAL OILS (BIACID) IMPROVE TECHNICAL PERFORMANCE OF BROILERS  

Microsoft Academic Search

Summary Antimicrobial growth promoters (AGP's) will soon no longer be available to the poultry producer in Europe and a similar outcome is envisaged for Australia. This paper discusses and reports on the research and developmental efforts within Provimi to provide the poultry industry with an effective alternative to AGP's consisting of a blend of volatile fatty acids and essential oils.

H. KLEIN-HESSLING; D. J. LANGHOUT; P. WIJTTEN

468

Volatile Aromatic Anesthetics Variably Impact Human ?-Aminobutyric Acid Type A Receptor Function  

Microsoft Academic Search

BACKGROUND: The -aminobutyric acid type A (GABAA) and N-methyl-d-aspartate (NMDA) receptors are important inhibitory and excitatory neurotransmitter receptors, respectively, in the central nervous system. At the concentrations required to produce immobility in the face of a noxious stimulus, volatile aromatic anesthetics inhibit NMDA receptors to varying degrees, strongly suggesting that they also act at other targets to produce immobilization. In

Elizabeth W. Kelly; Ken Solt; Douglas E. Raines

2007-01-01

469

Acid-volatile sulfide as a factor mediating cadmium and nickel bioavailability in contaminated sediments  

Microsoft Academic Search

The authors investigated the influence of sulfide, measured as acid-volatile sulfide (AVS), on the bioavailability of cadmium and nickel in sediments. Seventeen samples from an estuarine system heavily contaminated with cadmium and nickel were analyzed for AVS and simultaneously extracted metals (SEM) and tested in 10-d exposures with the amphipod Hyalella azteca and the oligochaete Lumbriculus variegatus. Molar SEM(cadmium +

Gerald T. Ankley; Gary L. Phipps; Edward N. Leonard; Duane A. Benoit; Vincent R. Mattson; Patricia A. Kosian; Anne M. Cotter; Joseph R. Dierkes; David J. Hansen; John D. Mahony

1991-01-01

470

Characterisation of calamansi (Citrus microcarpa). Part I: volatiles, aromatic profiles and phenolic acids in the peel.  

PubMed

Volatile compounds in the peel of calamansi (Citrus microcarpa) from Malaysia, the Philippines and Vietnam were extracted with dichloromethane and hexane, and then analysed by gas chromatography-mass spectroscopy/flame ionisation detector. Seventy-nine compounds representing >98% of the volatiles were identified. Across the three geographical sources, a relatively small proportion of potent oxygenated compounds was significantly different, exemplified by the highest amount of methyl N-methylanthranilate in Malaysian calamansi peel. Principal component analysis and canonical discriminant analysis were applied to interpret the complex volatile compounds in the calamansi peel extracts, and to verify the discrimination among the different origins. In addition, four common hydroxycinnamic acids (caffeic, p-coumaric, ferulic and sinapic acids) were determined in the methanolic extracts of calamansi peel using ultra-fast liquid chromatography coupled to photodiode array detector. The Philippines calamansi peel contained the highest amount of total phenolic acids. In addition, p-Coumaric acid was the dominant free phenolic acids, whereas ferulic acid was the main bound phenolic acid. PMID:23107679

Cheong, Mun Wai; Chong, Zhi Soon; Liu, Shao Quan; Zhou, Weibiao; Curran, Philip; Bin Yu

2012-03-07

471

AUTOMATED ANALYSIS OF AQUEOUS SAMPLES CONTAINING PESTICIDES, ACIDIC/BASIC/NEUTRAL SEMIVOLATILES AND VOLATILE ORGANIC COMPOUNDS BY SOLID PHASE EXTRACTION COUPLED IN-LINE TO LARGE VOLUME INJECTION GC/MS  

EPA Science Inventory

Data is presented on the development of a new automated system combining solid phase extraction (SPE) with GC/MS spectrometry for the single-run analysis of water samples containing a broad range of organic compounds. The system uses commercially available automated in-line 10-m...

472