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Sample records for volatile liquid compounds

  1. Determination of the solubility of low volatility liquid organic compounds in water using volatile-tracer assisted headspace gas chromatography.

    Science.gov (United States)

    Zhang, Shu-Xin; Chai, Xin-Sheng; Barnes, Donald G

    2016-02-26

    This study reports a new headspace gas chromatographic method (HS-GC) for the determination of water solubility of low volatility liquid organic compounds (LVLOs). The HS-GC analysis was performed on a set of aqueous solutions containing a range of concentrations of toluene-spiked (as a tracer) LVLOs, from under-saturation to over-saturation. A plot of the toluene tracer GC signal vs. the concentration of the LVLO results in two lines of different slopes that intersect at the concentration corresponding to the compound's solubility in water. The results showed that the HS-GC method has good precision (RSD solubility of LVLOs at elevated temperatures. This approach should be of special interest to those concerned about the impact of the presence of low-volatility organic liquids in waters of environmental and biological systems.

  2. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Contact Us Share Volatile Organic Compounds' Impact on Indoor Air Quality On this page: Introduction Sources Health Effects Levels in Homes Steps to Reduce Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds ( ...

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

    Science.gov (United States)

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

    2010-09-07

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

  4. Volatile Compounds Detected in Coconut Shell Liquid Smoke through Pyrolysis at a Fractioning Temperature of 350-420 C

    Directory of Open Access Journals (Sweden)

    Ruslin Hadanu

    2016-09-01

    Full Text Available This study evaluated the volatile components of liquid smoke from coconut shells obtained through the pyrolysis process at fraction 350-420 °C. The volatile compounds of liquid smoke from a coconut shell were analyzed using gas chromatography and mass spectrometry (GC-MS. Nineteen peaks were detected by GC-MS in the coconut shell liquid smoke, and 19 compounds also were identified. The volatile compounds were identified as follows based on their function group’s composition percentage: phenol (90.75%, carbonyl (3.71%, alcohol (1.81%, and benzene (3.73%, respectively. The liquid smoke contains a high ratio of phenol derivatives (90.75% in volatile profile. The phenol derivatives were the major volatile compounds found in the coconut shell liquid smoke.

  5. Role of Aerosol Liquid Water in Secondary Organic Aerosol Formation from Volatile Organic Compounds.

    Science.gov (United States)

    Faust, Jennifer A; Wong, Jenny P S; Lee, Alex K Y; Abbatt, Jonathan P D

    2017-02-07

    A key mechanism for atmospheric secondary organic aerosol (SOA) formation occurs when oxidation products of volatile organic compounds condense onto pre-existing particles. Here, we examine effects of aerosol liquid water (ALW) on relative SOA yield and composition from α-pinene ozonolysis and the photooxidation of toluene and acetylene by OH. Reactions were conducted in a room-temperature flow tube under low-NOx conditions in the presence of equivalent loadings of deliquesced (∼20 μg m(-3) ALW) or effloresced (∼0.2 μg m(-3) ALW) ammonium sulfate seeds at exactly the same relative humidity (RH = 70%) and state of wall conditioning. We found 13% and 19% enhancements in relative SOA yield for the α-pinene and toluene systems, respectively, when seeds were deliquesced rather than effloresced. The relative yield doubled in the acetylene system, and this enhancement was partially reversible upon drying the prepared SOA, which reduced the yield by 40% within a time scale of seconds. We attribute the high relative yield of acetylene SOA on deliquesced seeds to aqueous partitioning and particle-phase reactions of the photooxidation product glyoxal. The observed range of relative yields for α-pinene, toluene, and acetylene SOA on deliquesced and effloresced seeds suggests that ALW plays a complicated, system-dependent role in SOA formation.

  6. Selection of ionic liquids for enhancing the gas solubility of volatile organic compounds.

    Science.gov (United States)

    Gonzalez-Miquel, Maria; Palomar, Jose; Rodriguez, Francisco

    2013-01-10

    A systematic thermodynamic analysis has been carried out for selecting cations and anions to enhance the absorption of volatile organic compounds (VOCs) at low concentration in gaseous streams by ionic liquids (ILs), using COSMO-RS methodology. The predictability of computational procedure was validated by comparing experimental and COSMO-RS calculated Henry's law constant data over a sample of 125 gaseous solute-IL systems. For more than 2400 solute-IL mixtures evaluated, including 9 solutes and 270 ILs, it was found that the lower the activity coefficient at infinite dilution (γ(∞)) of solutes in the ILs, the more the exothermic excess enthalpy (H(E)) of the equimolar IL-solute mixtures. Then, the solubility of a representative sample of VOC solutes, with very different chemical nature, was screened in a wide number of ILs using COSMO-RS methodology by means of γ(∞) and H(E) parameters, establishing criteria to select the IL structures that promote favorable solute-solvent intermolecular interactions. As a result of this analysis, an attempt of classification of VOCs respect to their potential solubility in ILs was proposed, providing insights to rationally select the cationic and anionic species for a possible development of absorption treatments of VOC pollutants based on IL systems.

  7. OPTIMIZED DETERMINATION OF TRACE JET FUEL VOLATILE ORGANIC COMPOUNDS IN HUMAN BLOOD USING IN-FIELD LIQUID-LIQUID EXTRACTION WITH SUBSEQUENT LABORATORY GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC ANALYSIS AND ON-COLUMN LARGE VOLUME INJECTION

    Science.gov (United States)

    A practical and sensitive method to assess volatile organic compounds (VOCs) from JP-8 jet fuel in human whole blood was developed by modifying previously established liquid-liquid extraction procedures, optimizing extraction times, solvent volume, specific sample processing te...

  8. Synthesis and toxicity evaluation of hydrophobic ionic liquids for volatile organic compounds biodegradation in a two-phase partitioning bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Castillo, Alfredo Santiago [Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Université européenne de Bretagne (France); Guihéneuf, Solène, E-mail: solene.guiheneuf@wanadoo.fr [Université européenne de Bretagne, Université de Rennes 1, Sciences Chimiques de Rennes, UMR, CNRS 6226, Groupe Ingénierie Chimique & Molécules Pour le Vivant (ICMV), Bât. 10A, Campus de Beaulieu, Avenue du Général Leclerc, CS 74205, 35042 Rennes cedex (France); Le Guével, Rémy [Plate-forme ImPACcell Structure Fédérative de Recherche BIOSIT Université de Rennes 1, Bat. 8, Campus de Villejean, 2 Avenue du Pr. Leon Bernard, CS 34317, 35043 Rennes Cedex (France); Biard, Pierre-François [Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Université européenne de Bretagne (France); and others

    2016-04-15

    Highlights: • Description of a VOC depollution system suitable with industrial processes, TPPB. • Novel association of TPPB and hydrophobic ionic liquids. • Synthesis of several hydrophobic ionic liquids designed to fit desired properties. • Toxicity evaluation of these ILs towards cells, animals and bacteria. - Abstract: Synthesis of several hydrophobic ionic liquids (ILs), which might be selected as good candidates for degradation of hydrophobic volatile organic compounds in a two-phase partitioning bioreactor (TPPB), were carried out. Several bioassays were also realized, such as toxicity evaluation on activated sludge and zebrafish, cytotoxicity, fluoride release in aqueous phase and biodegradability in order to verify their possible effects in case of discharge in the aquatic environment and/or human contact during industrial manipulation. The synthesized compounds consist of alkylimidazoliums, functionalized imidazoliums, isoqinoliniums, triazoliums, sulfoniums, pyrrolidiniums and morpholiniums and various counter-ions such as: PF{sub 6}{sup −}, NTf{sub 2}{sup −} and NfO{sup −}. Toxicity evaluation on activated sludge of each compound (5% v/v of IL) was assessed by using a glucose uptake inhibition test. Toxicity against zebrafish and cytotoxicity were evaluated by the ImPACCell platform of Rennes (France). Fluoride release in water was estimated by regular measurements using ion chromatography equipment. IL biodegradability was determined by measuring BOD{sub 28} of aqueous samples (compound concentration,1 mM). All ILs tested were not biodegradable; while some of them were toxic toward activated sludge. Isoquinolinium ILs were toxic to human cancerous cell lines. Nevertheless no toxicity was found against zebrafish Danio rerio. Only one IL released fluoride after long-time agitation.

  9. Synthesis and toxicity evaluation of hydrophobic ionic liquids for volatile organic compounds biodegradation in a two-phase partitioning bioreactor.

    Science.gov (United States)

    Rodriguez Castillo, Alfredo Santiago; Guihéneuf, Solène; Le Guével, Rémy; Biard, Pierre-François; Paquin, Ludovic; Amrane, Abdeltif; Couvert, Annabelle

    2016-04-15

    Synthesis of several hydrophobic ionic liquids (ILs), which might be selected as good candidates for degradation of hydrophobic volatile organic compounds in a two-phase partitioning bioreactor (TPPB), were carried out. Several bioassays were also realized, such as toxicity evaluation on activated sludge and zebrafish, cytotoxicity, fluoride release in aqueous phase and biodegradability in order to verify their possible effects in case of discharge in the aquatic environment and/or human contact during industrial manipulation. The synthesized compounds consist of alkylimidazoliums, functionalized imidazoliums, isoqinoliniums, triazoliums, sulfoniums, pyrrolidiniums and morpholiniums and various counter-ions such as: PF6(-), NTf2(-) and NfO(-). Toxicity evaluation on activated sludge of each compound (5% v/v of IL) was assessed by using a glucose uptake inhibition test. Toxicity against zebrafish and cytotoxicity were evaluated by the ImPACCell platform of Rennes (France). Fluoride release in water was estimated by regular measurements using ion chromatography equipment. IL biodegradability was determined by measuring BOD28 of aqueous samples (compound concentration,1mM). All ILs tested were not biodegradable; while some of them were toxic toward activated sludge. Isoquinolinium ILs were toxic to human cancerous cell lines. Nevertheless no toxicity was found against zebrafish Danio rerio. Only one IL released fluoride after long-time agitation. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Exposure to volatile organic compounds and kidney dysfunction in thin film transistor liquid crystal display (TFT-LCD) workers.

    Science.gov (United States)

    Chang, Ta-Yuan; Huang, Kuei-Hung; Liu, Chiu-Shong; Shie, Ruei-Hao; Chao, Keh-Ping; Hsu, Wen-Hsin; Bao, Bo-Ying

    2010-06-15

    Many volatile organic compounds (VOCs) are emitted during the manufacturing of thin film transistor liquid crystal displays (TFT-LCDs), exposure to some of which has been reported to be associated with kidney dysfunction, but whether such an effect exists in TFT-LCD industry workers is unknown. This cross-sectional study aimed to investigate the association between exposure to VOCs and kidney dysfunction among TFT-LCD workers. The results showed that ethanol (1811.0+/-1740.4 ppb), acetone (669.0+/-561.0 ppb), isopropyl alcohol (187.0+/-205.3 ppb) and propylene glycol monomethyl ether acetate (PGMEA) (102.9+/-102.0 ppb) were the four dominant VOCs present in the workplace. The 63 array workers studied had a risk of kidney dysfunction 3.21-fold and 3.84-fold that of 61 cell workers and 18 module workers, respectively. Workers cumulatively exposed to a total level of isopropyl alcohol, PGMEA and propylene glycol monomethyl ether> or =324 ppb-year had a significantly higher risk of kidney dysfunction (adjusted OR=3.41, 95% CI=1.14-10.17) compared with those exposed to LCD industry, and cumulative exposure to specific VOCs might be associated with kidney dysfunction.

  11. Application of dispersive liquid-liquid microextraction and gas chromatography with mass spectrometry for the determination of oxygenated volatile organic compounds in effluents from the production of petroleum bitumen.

    Science.gov (United States)

    Boczkaj, Grzegorz; Makoś, Patrycja; Przyjazny, Andrzej

    2016-07-01

    We present a new procedure for the determination of oxygenated volatile organic compounds in samples of postoxidative effluents from the production of petroleum bitumens using dispersive liquid-liquid microextraction and gas chromatography with mass spectrometry. The eight extraction parameters were optimized for 43 oxygenated volatile organic compounds. The detection limits obtained ranged from 0.07 to 0.82 μg/mL for most of the analytes, the precision was good (relative standard deviation below 2.91% at the 5 μg/mL level and 4.75% at the limit of quantification), the recoveries for the majority of compounds varied from 70.6 to 118.9%, and the linear range was wide, which demonstrates the usefulness of the procedure. The developed procedure was used for the determination of oxygenated volatile organic compounds in samples of raw postoxidative effluents and in effluents after chemical treatment. In total, 23 compounds at concentration levels from 0.37 to 32.95 μg/mL were identified in real samples. The same samples were also analyzed in the SCAN mode, which resulted in four more phenol derivatives being identified and tentatively determined. The studies demonstrated the need for monitoring volatile organic compounds content in effluents following various treatments due to the formation of secondary oxygenated volatile organic compounds.

  12. Polymeric ionic liquid coatings versus commercial solid-phase microextraction coatings for the determination of volatile compounds in cheeses.

    Science.gov (United States)

    Trujillo-Rodríguez, María J; Yu, Honglian; Cole, William T S; Ho, Tien D; Pino, Verónica; Anderson, Jared L; Afonso, Ana M

    2014-04-01

    The extraction performance of four polymeric ionic liquid (PIL)-based solid-phase microextraction (SPME) coatings has been studied and compared to that of commercial SPME coatings for the extraction of 16 volatile compounds in cheeses. The analytes include 2 free fatty acids, 2 aldehydes, 2 ketones and 10 phenols and were determined by headspace (HS)-SPME coupled to gas chromatography (GC) with flame-ionization detection (FID). The PIL-based coatings produced by UV co-polymerization were more efficient than PIL-based coatings produced by thermal AIBN polymerization. Partition coefficients of analytes between the sample and the coating (Kfs) were estimated for all PIL-based coatings and the commercial SPME fiber showing the best performance among the commercial fibers tested: carboxen-polydimethylsyloxane (CAR-PDMS). For the PIL-based fibers, the highest K(fs) value (1.96 ± 0.03) was obtained for eugenol. The normalized calibration slope, which takes into account the SPME coating thickness, was also used as a simpler approximate tool to compare the nature of the coating within the determinations, with results entirely comparable to those obtained with estimated K(fs) values. The PIL-based materials obtained by UV co-polymerization containing the 1-vinyl-3-hexylimidazolium chloride IL monomer and 1,12-di(3-vinylimiazolium)dodecane dibromide IL crosslinker exhibited the best performance in the extraction of the select analytes from cheeses. Despite a coating thickness of only 7 µm, this copolymeric sorbent coating was capable of quantitating analytes in HS-SPME in a 30 to 2000 µg L(-1) concentration range, with correlation coefficient (R) values higher than 0.9938, inter-day precision values (as relative standard deviation in %) varying from 6.1 to 20%, and detection limits down to 1.6 µg L(-1).

  13. Optimization of dynamic headspace extraction system for measurement of halogenated volatile organic compounds in liquid or viscous samples

    Science.gov (United States)

    Taniai, G.; Oda, H.; Kurihara, M.; Hashimoto, S.

    2010-12-01

    Halogenated volatile organic compounds (HVOCs) produced in the marine environment are thought to play a key role in atmospheric reactions, particularly those involved in the global radiation budget and the depression of tropospheric and stratospheric ozone. To evaluate HVOCs concentrations in the various natural samples, we developed an automated dynamic headspace extraction method for the determination of 15 HVOCs, such as chloromethane, bromomethane, bromoethane, iodomethane, iodoethane, bromochloromethane, 1-iodopropane, 2-iodopropane, dibromomethane, bromodichloromethane, chloroiodomethane, chlorodibromomethane, bromoiodomethane, tribromomethane, and diiodomethane. Dynamic headspace system (GERSTEL DHS) was used to purge the gas phase above samples and to trap HVOCs on the adsorbent column from the purge gas. We measured the HVOCs concentrations in the adsorbent column with gas chromatograph (Agilent 6890N)- mass spectrometer (Agilent 5975C). In dynamic headspace system, an glass tube containing Tenax TA or Tenax GR was used as adsorbent column for the collection of 15 HVOCs. The parameters for purge and trap extraction, such as purge flow rate (ml/min), purge volume (ml), incubation time (min), and agitator speed (rpm), were optimized. The detection limits of HVOCs in water samples were 1270 pM (chloromethane), 103 pM (bromomethane), 42.1 pM (iodomethane), and 1.4 to 10.2 pM (other HVOCs). The repeatability (relative standard deviation) for 15 HVOCs were < 9 % except chloromethane (16.2 %) and bromomethane (11.0 %). On the basis of the measurements for various samples, we concluded that this analytical method is useful for the determination of wide range of HVOCs with boiling points between - 24°C (chloromethane) and 181°C (diiodomethane) for the liquid or viscous samples.

  14. atmospheric volatile organic compounds

    Directory of Open Access Journals (Sweden)

    A. R. Koss

    2016-07-01

    organic compounds (VOCs that cannot be ionized with H3O+ ions (e.g., in a PTR-MS or H3O+ CIMS instrument. Here we describe the adaptation of a high-resolution time-of-flight H3O+ CIMS instrument to use NO+ primary ion chemistry. We evaluate the NO+ technique with respect to compound specificity, sensitivity, and VOC species measured compared to H3O+. The evaluation is established by a series of experiments including laboratory investigation using a gas-chromatography (GC interface, in situ measurement of urban air using a GC interface, and direct in situ measurement of urban air. The main findings are that (1 NO+ is useful for isomerically resolved measurements of carbonyl species; (2 NO+ can achieve sensitive detection of small (C4–C8 branched alkanes but is not unambiguous for most; and (3 compound-specific measurement of some alkanes, especially isopentane, methylpentane, and high-mass (C12–C15 n-alkanes, is possible with NO+. We also demonstrate fast in situ chemically specific measurements of C12 to C15 alkanes in ambient air.

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

    Science.gov (United States)

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

    1997-09-01

    A flame ionization detector (FID) is used to detect volatile organic compounds that have been separated by water-only reversed-phase liquid chromatography (WRP-LC). The mobile phase is 100% water at room temperature, without use of organic solvent modifiers. An interface between the LC and detector is presented, whereby a helium stream samples the vapor of volatile components from individual drops of the LC eluent, and the vapor-enriched gas stream is sent to the FID. The design of the drop headspace cell is simple because the water-only nature of the LC separation obviates the need to do any organic solvent removal prior to gas phase detection. Despite the absence of organic modifier, hydrophobic compounds can be separated in a reasonable time due to the low phase volume ratio of the WRP-LC columns. The drop headspace interface easily handles LC flows of 1 mL/min, and, in fact, compound detection limits are improved at faster liquid flow rates. The transfer efficiency of the headspace interface was estimated at 10% for toluene in water at 1 mL/min but varies depending on the volatility of each analyte. The detection system is linear over more than 5 orders of 1-butanol concentration in water and is able to detect sub-ppb amounts of o-xylene and other aromatic compounds in water. In order to analyze volatile and nonvolatile analytes simultaneously, the FID is coupled in series to a WRP-LC system with UV absorbance detection. WRP-LC improves UV absorbance detection limits because the absence of organic modifier allows the detector to be operated in the short-wavelength UV region, where analytes generally have significantly larger molar absorptivities. The selectivity the headspace interface provides for flame ionization detection of volatiles is demonstrated with a separation of 1-butanol, 1,1,2-trichloroethane (TCE), and chlorobenzene in a mixture of benzoic acid in water. Despite coelution of butanol and TCE with the benzoate anion, the nonvolatile benzoate anion

  16. Determination of volatile compounds in cider apple juices using a covalently bonded ionic liquid coating as the stationary phase in gas chromatography.

    Science.gov (United States)

    Pello-Palma, Jairo; González-Álvarez, Jaime; Gutiérrez-Álvarez, María Dolores; Dapena de la Fuente, Enrique; Mangas-Alonso, Juan José; Méndez-Sánchez, Daniel; Gotor-Fernández, Vicente; Arias-Abrodo, Pilar

    2017-04-01

    A chromatographic method for the separation of volatile compounds in Asturian cider apple juices has been developed. For this separation purpose, a monocationic imidazolium-based ionic liquid bearing a reactive terminal iodine atom was synthesized by a quaternization-anion exchange chemical sequence. Next, the gas chromatography (GC) stationary phase was prepared by covalently linking the imidazolium monolith to the reactive silanol groups of the inner capillary wall at 70 °C. This coated GC column exhibited good thermal stability (290 °C), as well as good efficiency (2000 plates/m) in the separation of volatile compounds from Asturian apple cider juices, and was characterized using the Abraham solvation parameter model. The intra-day and inter-day precision of the chromatographic method was evaluated, obtaining relative standard deviations from 3.7 to 12.9% and from 7.4 to 18.0%, respectively. Furthermore, recoveries from 82.5 to 122% were achieved. Graphical Abstract Covalent bonding of an ionic liquid to inner column wall led to a great improvement of the separation efficiencies of stationary phases in gas chromatography.

  17. Volatile flavor compounds in yogurt: a review.

    Science.gov (United States)

    Cheng, Hefa

    2010-11-01

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

  18. Analyzing volatile compounds in dairy products

    Science.gov (United States)

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

  19. 40 CFR 60.112b - Standard for volatile organic compounds (VOC).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds... organic compounds (VOC). (a) The owner or operator of each storage vessel either with a design capacity... for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for...

  20. Characterisation of selected volatile organic compounds in ...

    African Journals Online (AJOL)

    kshale

    2013-05-15

    May 15, 2013 ... spectrometry. K. Shale1*, J. Mukamugema2, R. J. Lues1, P. Venter3 and K. K. Mokoena1 ..... Cajka T, Riddellova K, Tomaniova M, Hajslova J (2010). Recognition of ... volatile organic compounds of coniferous needle litter.

  1. Optimized determination of trace jet fuel volatile organic compounds in human blood using in-field liquid-liquid extraction with subsequent laboratory gas chromatographic-mass spectrometric analysis and on-column large-volume injection.

    Science.gov (United States)

    Liu, S; Pleil, J D

    2001-03-05

    A practical and sensitive method to assess volatile organic compounds (VOCs) from JP-8 jet fuel in human whole blood was developed by modifying previously established liquid-liquid extraction procedures, optimizing extraction times, solvent volume, specific sample processing techniques, and a new on-column large-volume injection method for GC-MS analysis. With the optimized methods, the extraction efficiency was improved by 4.3 to 20.1 times and the detection sensitivity increased up to 660 times over the standard method. Typical detection limits in the parts-per-trillion (ppt) level range were achieved for all monitored JP-8 constituents; this is sufficient for assessing human fuels exposures at trace environmental levels as well as occupational exposure levels. The sample extractions are performed in the field and only solvent extracts need to be shipped to the laboratory. The method is implemented with standard biological laboratory equipment and a modest bench-top GC-MS system.

  2. Volatile compounds in meat and meat products

    Directory of Open Access Journals (Sweden)

    Monika KOSOWSKA

    Full Text Available Abstract Meaty flavor is composed of a few hundreds of volatile compounds, only minor part of which are responsible for the characteristic odor. It is developed as a result of multi-directional reactions proceeding between non-volatile precursors contained in raw meat under the influence of temperature. The volatile compounds are generated upon: Maillard reactions, lipid oxidation, interactions between Maillard reaction products and lipid oxidation products as well as upon thiamine degradation. The developed flavor is determined by many factors associated with: raw material (breed, sex, diet and age of animal, conditions and process of slaughter, duration and conditions of meat storage, type of muscle, additives applied and the course of the technological process. The objective of this review article is to draw attention to the issue of volatile compounds characteristic for meat products and factors that affect their synthesis.

  3. Volatile organic compound emissions from silage systems

    Science.gov (United States)

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

  4. Isolation and preconcentration of volatile organic compounds from water; Review

    Energy Technology Data Exchange (ETDEWEB)

    Namiesnik, J.; Gorecki, T.; Biziuk, M.; Torres, L. (Technical Univ. of Gdansk (Poland) Ecole Nationale Superieure de Chimie, Toulouse (France))

    1990-10-01

    Methods for the isolation and/or concentration of volatile organic compounds from water samples for trace organic analysis by gas chromatography are reviewed. The following basic groups of methods are discussed: liquid-liquid extraction, adsorption on solid sorbents, extraction with gas (gas stripping and static and dynamic headspace techniques) and membrane processes. The theoretical bases of these methods are discussed. Experimental arrangements for the isolation and/or concentration of volatile compounds from water are presented and discussed with respect to their efficiency. The applicability of the described methods to the isolation and/or concentration of various organic compounds from waters of various origins is discussed. 26 figs., 7 tabs., 695 refs.

  5. Volatile compound formation during argan kernel roasting.

    Science.gov (United States)

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

    2013-01-01

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

  6. Effect on microorganisms of volatile compounds released from germinating seeds.

    Science.gov (United States)

    Schenck, S; Stotzky, G

    1975-10-01

    Volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source. Growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium. Volatiles caused increased growth of Pseudomonas fluorescens, Bacillus cereus, Erwinia carotovora, Agrobacterium tumefaciens, A. radiobacter, Rhizobium japonicum, Mucor mucedo, Fusarium oxysporum f. conglutinans, Trichoderma viride, and Penicillium vermiculatum but not of Sarcina lutea, Serratia marcescens, Chaetomium globosum, or Schizophyllum commune. Spores of Trichoderma viride showed higher germination in the presence of volatiles. Effects on growth were apparent only during the first 3 or 4 days after planting the seeds. Killed or dried seeds had no effect. The volatiles did not support microbial growth in the absence of nitrogen nor did they supply growth factors. Passing volatiles through KMnO4 or hydrazone reduced growth of the bacteria, indicating that oxidizable organic compounds, primarily aldehydes, were the active components. The volatiles were not absorbed by sterile soil, clay minerals, or water, but they were absorbed by non-steril soil and activated charcoal.

  7. Marine Vibrio Species Produce the Volatile Organic Compound Acetone

    OpenAIRE

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

    1995-01-01

    While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine...

  8. Factors affecting the volatilization of volatile organic compounds from wastewater

    Directory of Open Access Journals (Sweden)

    Junya Intamanee

    2006-09-01

    Full Text Available This study aimed to understand the influence of the wind speed (U10cm, water depth (h and suspended solids (SS on mass transfer coefficient (KOLa of volatile organic compounds (VOCs volatilized from wastewater. The novelty of this work is not the method used to determine KOLa but rather the use of actual wastewater instead of pure water as previously reported. The influence of U10cm, h, and SS on KOLa was performed using a volatilization tank with the volume of 100-350 L. Methyl Ethyl Ketone (MEK was selected as a representative of VOCs investigated here in. The results revealed that the relationship between KOLa and the wind speeds falls into two regimes with a break at the wind speed of 2.4 m/s. At U10cm 2.4 m/s, KOLa increased more rapidly. The relationship between KOLa and U10cm was also linear but has a distinctly higher slope. For the KOLa dependency on water depth, the KOLa decreased significantly with increasing water depth up to a certain water depth after that the increase in water depth had small effect on KOLa. The suspended solids in wastewater also played an important role on KOLa. Increased SS resulted in a significant reduction of KOLa over the investigated range of SS. Finally, the comparison between KOLa obtained from wastewater and that of pure water revealed that KOLa from wastewater were much lower than that of pure water which was pronounced at high wind speed and at small water depth. This was due the presence of organic mass in wastewater which provided a barrier to mass transfer and reduced the degree of turbulence in the water body resulting in low volatilization rate and thus KOLa. From these results, the mass transfer model for predicting VOCs emission from wastewater should be developed based on the volatilization of VOCs from wastewater rather than that from pure water.

  9. Organic liquids storage tanks volatile organic compounds (VOCS) emissions dispersion and risk assessment in developing countries: the case of Dar-es-Salaam City, Tanzania.

    Science.gov (United States)

    Jackson, Msafiri M

    2006-05-01

    The emission estimation of nine volatile organic compounds (VOCs) from eight organic liquids storage tanks companies in Dar-es-Salaam City Tanzania has been done by using US EPA standard regulatory storage tanks emission model (TANKS 4.9b). Total VOCs atmospheric emission has been established to be 853.20 metric tones/yr. It has been established further that petrol storage tanks contribute about 87% of total VOCs emitted, while tanks for other refined products and crude oil were emitting 10% and 3% of VOCs respectively. Of the eight sources (companies), the highest emission value from a single source was 233,222.94 kg/yr and the lowest single source emission value was 6881.87 kg/yr. The total VOCs emissions estimated for each of the eight sources were found to be higher than the standard level of 40,000 kg/yr per source for minor source according to US EPA except for two sources, which were emitting VOCs below the standard level. The annual emissions per single source for each of the VOCs were found to be below the US EPA emissions standard which is 2,000 kg/yr in all companies except the emission of hexane from company F1 which was slightly higher than the standard. The type of tanks used seems to significantly influence the emission rate. Vertical fixed roof tanks (VFRT) emit a lot more than externally floating roof tanks (EFRT) and internally floating roof tanks (IFRT). The use of IFRT and EFRT should be encouraged especially for storage of petrol which had highest atmospheric emission contribution. Model predicted atmospheric emissions are less than annual losses measured by companies in all the eight sources. It is possible that there are other routes for losses beside atmospheric emissions. It is therefore important that waste reduction efforts in these companies are directed not only to reducing atmospheric emissions, but also prevention of the spillage and leakage of stored liquid and curbing of the frequently reported illegal siphoning of stored products

  10. Identification of non-volatile compounds and their migration from hot melt adhesives used in food packaging materials characterized by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Vera, Paula; Canellas, Elena; Nerín, Cristina

    2013-05-01

    The identification of unknown non-volatile migrant compounds from adhesives used in food contact materials is a very challenging task because of the number of possible compounds involved, given that adhesives are complex mixtures of chemicals. The use of ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-MS/QTOF) is shown to be a successful tool for identifying non-targeted migrant compounds from two hot melt adhesives used in food packaging laminates. Out of the seven migrants identified and quantified, five were amides and one was a compound classified in Class II of the Cramer toxicity. None of the migration values exceeded the recommended Cramer exposure values.

  11. Volatile compounds of commercial Milano salami.

    Science.gov (United States)

    Meynier, A; Novelli, E; Chizzolini, R; Zanardi, E; Gandemer, G

    1999-02-01

    The relationship between extracted volatiles of Milano salami, one of the main dry-cured sausages produced in Italy, and their olfactory properties was studied. Volatile compounds were extracted by a purge-and-trap method, quantified using a flame ionisation detector and identified by mass spectrometry. Olfactory analysis was performed by sniffing the gas chromatographic effluent. Nearly 80 compounds were identified and quantified: most came from spices (60.5%), 18.9% from lipid oxidation, 11.8% from amino acid catabolism and 4.9% from fermentation processes. Panellists detected 19 odours by sniffing. These odours were associated with spices, lipid oxidation or fermentation and were in agreement with the contributions of each reaction to the overall aroma of the product.

  12. Volatile Sulfur Compounds from Livestock Production

    DEFF Research Database (Denmark)

    Kasper, Pernille

    2017-01-01

    Volatile sulfur compounds, i.e. hydrogen sulfide, methanethiol and dimethyl sulfide have been identified as key odorants in livestock production due to their high concentration levels and low odor threshold values. At the same time their removal with abatement technologies based on mass transfer...... and, thus, odor removal in these systems. In this context, two processes based on the absorptive oxidation of sulfur compounds in trickling filters containing metal catalysts were examined. One process with iron chelated by ethylenediaminetetraacetic acid (EDTA) was shown to remove hydrogen sulfide...... that the original sample composition was significantly impaired due to adsorption and diffusion at the walls of the measuring equipment. Generally, sulfur compounds were best preserved in both olfactometers and sample bags, while carboxylic acids, 4-methylphenol and trimethylamine were found to undergo substantial...

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

    Science.gov (United States)

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

    2016-05-01

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

  14. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-06-01

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

  15. Volatile organic compound detection using nanostructured copolymers.

    Science.gov (United States)

    Li, Bo; Sauvé, Genevieve; Iovu, Mihaela C; Jeffries-El, Malika; Zhang, Rui; Cooper, Jessica; Santhanam, Suresh; Schultz, Lawrence; Revelli, Joseph C; Kusne, Aaron G; Kowalewski, Tomasz; Snyder, Jay L; Weiss, Lee E; Fedder, Gary K; McCullough, Richard D; Lambeth, David N

    2006-08-01

    Regioregular polythiophene-based conductive copolymers with highly crystalline nanostructures are shown to hold considerable promise as the active layer in volatile organic compound (VOC) chemresistor sensors. While the regioregular polythiophene polymer chain provides a charge conduction path, its chemical sensing selectivity and sensitivity can be altered either by incorporating a second polymer to form a block copolymer or by making a random copolymer of polythiophene with different alkyl side chains. The copolymers were exposed to a variety of VOC vapors, and the electrical conductivity of these copolymers increased or decreased depending upon the polymer composition and the specific analytes. Measurements were made at room temperature, and the responses were found to be fast and appeared to be completely reversible. Using various copolymers of polythiophene in a sensor array can provide much better discrimination to various analytes than existing solid state sensors. Our data strongly indicate that several sensing mechanisms are at play simultaneously, and we briefly discuss some of them.

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

    Science.gov (United States)

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

    2013-01-01

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

  17. Biogenic volatile organic compounds - small is beautiful

    Science.gov (United States)

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

    2012-12-01

    While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to allelopathy. A gradient of monoterpene concentration was found in soil around Pinus sylvestris and Pinus halepensis, decreasing with distance from the tree. Some compounds (α-pinene, sabinene, humulene and caryophyllene) in mineral soil were linearly correlated with the total amount of each compound in the overlying litter, indicating that litter might be the dominant source of these compounds. However, α-pinene did not fall within the correlation, indicating a source other than litter, probably root exudates. We also show that rhizosphere bVOCs can be a carbon source for soil microbes. In a horizontal gradient from Populus tremula trees, microbes closest to the tree trunk were better enzymatically equipped to metabolise labeled monoterpene substrate. Monoterpenes can also increase the degradation rate in soil of the persistant organic pollutants, likely acting as analogues for the cometabo-lism of polychlorinated biphenyls (PCBs) Flowers of a ginger species (Alpinia kwangsiensis) and a fig species (Ficus hispida) showed different bVOC signals pre- and post pollination. For Ficus hispida, there are three floral stages of a fig-wasp dependency mechanism: receptive, post pollinator and interfloral. Of 28 compounds detected, transcaryophyllene with trans-β-farnesene were the most important at the receptor stage, trans-caryophyllene was the most abundant at the post-pollinator stage, and isoprene was the most abundant in the interfloral stage. Alpinia kwangsiensis presents two morphologies for the reproductive parts of the flower. The "anaflexistyle" morphology has the flower style lowered in the

  18. Measurement of volatile organic compounds inside automobiles.

    Science.gov (United States)

    Fedoruk, Marion J; Kerger, Brent D

    2003-01-01

    The objective of the current study was to evaluate the types and concentrations of volatile organic compounds (VOCs) in the passenger cabin of selected sedan automobiles under static (parked, unventilated) and specified conditions of operation (i.e., driving the vehicle using air conditioning alone, vent mode alone, or driver's window half open). Data were collected on five different passenger sedan vehicles from three major automobile manufacturers. Airborne concentrations were assessed using 90-min time-weighted average (TWA) samples under U.S. Environmental Protection Agency (USEPA) Method IP-1B to assess individual VOC compounds and total VOCs (TVOCs) calibrated to toluene. Static vehicle testing demonstrated TVOC levels of approximately 400-800 microg/m(3) at warm interior vehicle temperatures (approximately 80 degrees F), whereas TVOCs at least fivefold higher were observed under extreme heat conditions (e.g., up to 145 degrees F). The profile of most prevalent individual VOC compounds varied considerably according to vehicle brand, age, and interior temperature tested, with predominant compounds including styrene, toluene, and 8- to 12-carbon VOCs. TVOC levels under varied operating conditions (and ventilation) were generally four- to eightfold lower (at approximately 50-160 microg/m(3)) than the static vehicle measurements under warm conditions, with the lowest measured levels generally observed in the trials with the driver's window half open. These data indicate that while relatively high concentrations of certain VOCs can be measured inside static vehicles under extreme heat conditions, normal modes of operation rapidly reduce the inside-vehicle VOC concentrations even when the air conditioning is set on recirculation mode.

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

    Science.gov (United States)

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

    2015-05-01

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

  20. Volatile Organic Compound Analysis in Istanbul

    Science.gov (United States)

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

    2012-04-01

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

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

    Science.gov (United States)

    2010-07-01

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

  2. 40 CFR 60.542 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.542 Section 60.542 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  3. 40 CFR 60.442 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds... Pressure Sensitive Tape and Label Surface Coating Operations § 60.442 Standard for volatile organic compounds. (a) On and after the date on which the performance test required by § 60.8 has been...

  4. 40 CFR 60.622 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

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

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

    Science.gov (United States)

    2010-07-01

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

  6. 40 CFR 60.712 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

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

  7. 40 CFR 60.492 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

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

  8. 40 CFR 60.392 - Standards for volatile organic compounds

    Science.gov (United States)

    2010-07-01

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

  9. 40 CFR 60.722 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

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

  10. 40 CFR 60.452 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

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

  11. 40 CFR 60.602 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

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

  12. 40 CFR 60.742 - Standards for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

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

  13. Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

    Science.gov (United States)

    Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

    2017-04-01

    Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Volatile organic compound remedial action project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-12-01

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

  15. 40 CFR 60.432 - Standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

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

  16. BIOCONCENTRATION FACTORS FOR VOLATILE ORGANIC COMPOUNDS IN VEGETATION

    Science.gov (United States)

    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...

  17. Analytical performance of three commonly used extraction methods for the gas chromatography-mass spectrometry analysis of wine volatile compounds.

    Science.gov (United States)

    Andujar-Ortiz, I; Moreno-Arribas, M V; Martín-Alvarez, P J; Pozo-Bayón, M A

    2009-10-23

    The analytical performance of three extraction procedures based on cold liquid-liquid extraction using dicloromethane (LLE), solid phase extraction (SPE) using a styrene-divinylbenzene copolymer and headspace solid phase microextraction (SPME) using a carboxen-polydimethylsiloxane coated fibre has been evaluated based on the analysis of 30 representative wine volatile compounds. From the comparison of the three procedures, LLE and SPE showed very good linearity covering a wide range of concentrations of wine volatile compounds, low detection limits, high recovery for most of the volatile compounds under study and higher sensitivity compared to the headspace-SPME procedure. The latter showed in general, poor recovery for polar volatile compounds. Despite some drawbacks associated with the LLE and SPE procedures such as the more tedious sampling treatment and the use of organic solvents, the analytical performance of both procedures showed that they are more adequate for the analysis of wine volatiles.

  18. Separation and Identification of Volatile Flavor Compounds in High-Salt Liquid State-Fermented Soy Sauce%高盐稀态酱油挥发性风味物质的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    高献礼; 赵谋明; 崔春; 曹鸣凯; 李丹

    2009-01-01

    分别采用固相微萃取(SPME)、同时蒸馏萃取(VSDE)和直接溶剂萃取(DSE)法对高盐稀态酱油挥发性风味物质进行分离、浓缩,并利用气质联用色谱(GC-MS)对其挥发性风味物质进行鉴定.试验共鉴定出147种风味化合物,其中酸类17种、醇类12种、醛类16种、酯类36种、呋喃(酮)类12种、酮类13种、杂环化合物14种、酚类8种、吡喃(酮)类6种、吡嗪类4种、吡咯(酮)类3种、含硫化合物6种.研究结果表明,主要挥发性风味化合物为酯、酸、醛、杂环化合物和醇类,其中酯类化合物的数量和相对含量最多;此外,有16种日式和韩式酱油中的关键风味化合物在国产高盐稀态酱油中被检出.%In this paper, such technologies as solid-phase micro-extraction (SPME), simultaneous steam distillation-extraction (VSDE) and direct solvent extraction (DSE) were employed to separate and concentrate the volatile flavor compounds in high-salt liquid state-fermented soy sauce, and the extracts were identified by means of gas chromatography-mass spectrometry (GC-MS). 147 flavor compounds, including 17 kinds of acids, 12 kinds of alcohols, 16 kinds of aldehydes, 36 kinds of esters, 12 kinds of furan(one)s, 13 kinds of ketones, 14 kinds of he-〖JP2〗 terocyclic compounds, 8 kinds of phenols, 6 kinds of pyran(one)s, 4 kinds of pyrazines, 3 kinds of pyrrol(idon)es〖JP〗 and 6 kinds of sulfur-containing compounds, were then identified. The results indicate that, in the dominant volatile flavor compounds in the soy sauce, namely, esters, acids, alcohols, aldehydes and heterocyclic compounds, esters are of the most species and of the highest relative content; and that 16 aroma-impact compounds of Japanese and Korean soy sauces were detected from Chinese high-salt liquid state-fermented soy sauce.

  19. Evolution of Volatile Compounds during the Distillation of Cognac Spirit.

    Science.gov (United States)

    Awad, Pierre; Athès, Violaine; Decloux, Martine Esteban; Ferrari, Gérald; Snakkers, Guillaume; Raguenaud, Patrick; Giampaoli, Pierre

    2017-09-06

    Cognac wine spirit has a complex composition in volatile compounds which contributes to its organoleptic profile. This work focused on the batch distillation process and, in particular, on volatile compounds specifically produced by chemical reactions during the distillation of Cognac wine spirit, traditionally conducted in two steps with charentais pot stills. The aim of this study was to characterize these volatile compounds formed during distillation. Sampling has been performed on the distillates and inside the boiler during a typical Cognac distillation. The analysis of these samples allowed us to perform a mass balance and to point out several types of volatile compounds whose quantities strongly increased during the distillation process. These compounds were distinguished by their chemical family. It has been found that the first distillation step was decisive for the formation of volatile compounds. Moreover, 2 esters, 3 aldehydes, 12 norisoprenoids, and 3 terpenes were shown to be generated during the process. These results suggest that some volatile compounds found in Cognac spirit are formed during distillation due to chemical reactions induced by high temperature. These findings give important indications to professional distillers in order to enhance the product's quality.

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

    Data.gov (United States)

    U.S. Environmental Protection Agency — Supporting information Tables S3 and S4 list emission factors in g/kg of speciated volatile and particulate organic compounds emitted from peat burning. Peat samples...

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

    Science.gov (United States)

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

    2015-02-15

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

  2. Total volatile organic compounds (TVOC) in indoor air quality investigations

    DEFF Research Database (Denmark)

    Mølhave, L.; Clausen, Geo; Berglund, B.

    1997-01-01

    The amount of volatile organic compounds (VOCs) in indoor air, usually called TVOC (total volatile organic compounds), has been measured using different definitions and techniques which yield different results. This report recommends a definition of TVOC referring to a specified range of VOCs...... for characterizing indoor pollution and for improving source control as required from the points of view of health, comfort, energy efficiency and sustainability. (C) Indoor Air (1997)....

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

    OpenAIRE

    Bennett, Joan W.; Arati A. Inamdar

    2015-01-01

    Volatile organic compounds (VOCs) are carbon-compounds that easily evaporate at room temperature. Toxins are biologically produced poisons; mycotoxins are those toxins produced by microscopic fungi. All fungi emit blends of VOCs; the qualitative and quantitative composition of these volatile blends varies with the species of fungus and the environmental situation in which the fungus is grown. These fungal VOCs, produced as mixtures of alcohols, aldehydes, acids, ethers, esters, ketones, terpe...

  4. Measurement of volatile organic compounds in human blood.

    OpenAIRE

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

    1996-01-01

    Volatile organic compounds (VOCs) are an important public health problem throughout the developed world. Many important questions remain to be addressed in assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in the analytical determination of VOCs. The analytical methodology chosen to measure toxicants in biological materials must be well validated and carefully carried out; poor quality assurance can lead to invalid resul...

  5. Characterization of volatile and non-volatile compounds of fresh pepper (Capsicum annuum)

    NARCIS (Netherlands)

    Eggink, P.M.; Haanstra, J.P.W.; Tikunov, Y.M.; Bovy, A.G.; Visser, R.G.F.

    2010-01-01

    In this study volatile and non-volatile compounds and several agronomical important parameters were measured in mature fruits of elite sweet pepper breeding lines and hybrids and several genebank accessions from different Capsicum species. The sweet pepper breeding lines and hybrids were chosen to

  6. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  7. Volatile compounds of some popular Mediterranean seafood species

    Directory of Open Access Journals (Sweden)

    I. GIOGIOS

    2013-06-01

    Full Text Available The volatile compounds of highly commercialised fresh Mediterranean seafood species, including seven fish (sand-smelt Atherina boyeri, picarel Spicara smaris, hake Merluccius merluccius, pilchard Sardina pilchardus, bogue Boobps boops, anchovy Engraulis encrasicolus and striped-mullet Mullus barbatus, squid (Loligo vulgaris, shrimp (Parapenaeus longirostris and mussel (Mytilus galloprovincialis, were evaluated by simultaneous steam distillation-extraction and subsequent GC-MS analysis. A total of 298 volatile compounds were detected. The mussels contained the highest total concentration of volatile compounds, while pilchard among fish species contained the highest number and concentrations of volatile compounds. Individual patterns of volatile compounds have been distinguished. The fish species when compared to the shellfish species studied, contained 6 to 30 times more 1-penten-3-ol, higher quantities of 2-ethylfuran, and 2,3-pentanedione, which was absent from the shellfish species. Pilchard is characterized by a high concentration of alcohols, shrimps by the high presence of amines and S-compounds, while mussels by high amounts of aldehydes, furans, and N-containing compounds (pyridine, pyrazines and pyrrols. The fatty acid-originating carbonyl compounds in fish seem to be related to the species’ fat content.

  8. Volatile compounds of some popular Mediterranean seafood species

    Directory of Open Access Journals (Sweden)

    I. GIOGIOS

    2013-07-01

    Full Text Available The volatile compounds of highly commercialised fresh Mediterranean seafood species, including seven fish (sand-smelt Atherina boyeri, picarel Spicara smaris, hake Merluccius merluccius, pilchard Sardina pilchardus, bogue Boobps boops, anchovy Engraulis encrasicolus and striped-mullet Mullus barbatus, squid (Loligo vulgaris, shrimp (Parapenaeus longirostris and mussel (Mytilus galloprovincialis, were evaluated by simultaneous steam distillation-extraction and subsequent GC-MS analysis. A total of 298 volatile compounds were detected. The mussels contained the highest total concentration of volatile compounds, while pilchard among fish species contained the highest number and concentrations of volatile compounds. Individual patterns of volatile compounds have been distinguished. The fish species when compared to the shellfish species studied, contained 6 to 30 times more 1-penten-3-ol, higher quantities of 2-ethylfuran, and 2,3-pentanedione, which was absent from the shellfish species. Pilchard is characterized by a high concentration of alcohols, shrimps by the high presence of amines and S-compounds, while mussels by high amounts of aldehydes, furans, and N-containing compounds (pyridine, pyrazines and pyrrols. The fatty acid-originating carbonyl compounds in fish seem to be related to the species’ fat content.

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

    Science.gov (United States)

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

    2004-01-01

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

  10. Permeation of volatile compounds through starch films

    NARCIS (Netherlands)

    Yilmaz, G.; Jongboom, R.O.J.; Feil, H.; Dijk, van C.; Hennink, W.E.

    2004-01-01

    The aim of this study was to gain insight into the factors that affect the permeation of volatiles through starch films. These films were obtained by casting gelatinized starch/water/glycerol mixtures. The films were dried and conditioned under different conditions (temperature and relative humidity

  11. The volatile compound BinBase mass spectral database

    Directory of Open Access Journals (Sweden)

    Barupal Dinesh K

    2011-08-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2017-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-06-01

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

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

    Science.gov (United States)

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

    2007-12-01

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

  16. Comparation sensory characteristic, non-volatile compounds, volatile compounds and antioxidant activity of MRPs by novel gradient temperature-elevating and traditional isothermal methods

    National Research Council Canada - National Science Library

    Huang, Meigui; Zhang, Xiaoming; Karangwa, Eric

    2015-01-01

    .... The main purpose of the present study was to compare the color, taste characteristic, non-volatile compounds, volatile compounds and antioxidant activity of MRPs prepared by the novel gradient...

  17. Volatile compounds in the thermoplastic extrusion of bovine rumen

    Directory of Open Access Journals (Sweden)

    Ana Carolina Conti e Silva

    2008-01-01

    Full Text Available The volatile compounds of raw and extruded bovine rumen, extracted by dynamic headspace, were separated by gas chromatography and analyzed by GC-MS. Raw and extruded materials presented thirty-two volatile compounds. The following compounds were identified in raw bovine rumen: heptane, 1-heptene, 4-methyl-2-pentanone, toluene, hexanal, ethyl butyrate, o-xylene, m-xylene, p-xylene, heptanal, limonene, nonanal, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane and octadecane. The following compounds were identified in the extruded material: 1-heptene, 2,4-dimethylhexane, toluene, limonene, undecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane and nonadecane. Mass spectra of some unidentified compounds indicated the presence of hydrocarbons with branched chains or cyclic structure.

  18. Volatile organic compounds and oxides of nitrogen. Further emission reductions

    Energy Technology Data Exchange (ETDEWEB)

    Froste, H. [comp.

    1996-12-31

    This report presents the current status in relation to achievement of the Swedish Environmental target set by Parliament to reduce emission of volatile organic compounds by 50 per cent between 1988 and 2000. It also instructed the Agency to formulate proposed measures to achieve a 50 per cent reduction of emission of nitrogen oxides between 1985 and 2005. The report presents an overall account of emission trends for volatile organic compounds (from all sectors) and nitrogen oxides (from the industry sector) and steps proposed to achieve further emission reductions. 43 refs

  19. Volatile Organic Compounds are Ghosts for Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Prakash R. Somani

    2014-11-01

    Full Text Available All our efforts to demonstrate a multifunctional device – photovoltaic gas sensor (i.e. solar cell which show photovoltaic action depending on the gas / volatile organic compounds (VOC in the surrounding atmosphere yielded negative results. Photovoltaic performance of the organic solar cells under study degraded – almost permanently by exposing them to volatile organic compounds (VOCs. Although, the proposed multifunctional device could not be demonstrated; Present investigations yielded very important result that organic solar cells have problems not only with oxygen and humidity (known facts but also with many VOCs and hazardous gases – making lamination / encapsulation step mandatory for their practical utilization.

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

    Energy Technology Data Exchange (ETDEWEB)

    Barbarin, N.; Crucq, A.S.; Tilquin, B. [Universite Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium)

    1996-12-01

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

  1. [Determination of volatile organic compounds in atmospheric environment].

    Science.gov (United States)

    Chen, H W; Li, G K; Li, H; Zhang, Z X; Wang, B G; Li, T; Luo, H K

    2001-11-01

    It is well known that volatile organic compounds (VOCs) are the main photochemical pollutants and ozone precursors of the photochemical smog. Investigation of photochemical pollution in the ambient air must focus on VOCs, but the concentration of VOCs in ambient air is in a very low level (10(-9)-10(-12), volume fraction), so there are difficulties in the determination of VOCs. In this work, based on the TO14A and TO15 methods recommended by the Environmental Protection Agency of United States, an improved method for the determination of fifty-six VOCs, mainly O3 precursors, in atmospheric environment was developed. Operating conditions of VOCs preconcentrator, gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were optimized. Air sample was first frozen by liquid nitrogen, and then H2O and CO2 were eliminated in the VOCs preconcentrator. The preconcentrated VOCs sample was injected to GC and detected by MS or hydrogen flame ionization detector (FID). The C2-C10 hydrocarbons were separated effectively in capillary columns under the high concentration of CO2. The detection limits were 0.1 microgram.m-3 and the relative standard deviations were in the range from 2.57% to 9.82%. This method has been used for the determination of VOCs in real samples. The results were satisfactory.

  2. 76 FR 18893 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

    Science.gov (United States)

    2011-04-06

    ... Organic Compound Emission Control Measures for Lithographic and Letterpress Printing in Cleveland AGENCY... volatile organic compound (VOC) rule. These rule revisions specify compliance dates for subject facilities... approved offset lithographic and letterpress printing volatile organic compound (VOC) rule for...

  3. 76 FR 4835 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

    Science.gov (United States)

    2011-01-27

    ... Organic Compound Reinforced Plastics Composites Production Operations Rule AGENCY: Environmental... control of volatile organic compound (VOC) emissions from reinforced plastic composites production..., Volatile organic compounds. Dated: January 14, 2011. Susan Hedman, Regional Administrator, Region...

  4. 76 FR 41086 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

    Science.gov (United States)

    2011-07-13

    ... Organic Compound Reinforced Plastic Composites Production Operations Rule AGENCY: Environmental Protection...) a new rule for the control of volatile organic compound (VOC) emissions from reinforced plastic..., Reporting and recordkeeping requirements, Volatile organic compounds. Dated: June 24, 2011. Susan...

  5. Supercritical fluid extraction of volatile and non-volatile compounds from Schinus molle L.

    Directory of Open Access Journals (Sweden)

    M. S. T. Barroso

    2011-06-01

    Full Text Available Schinus molle L., also known as pepper tree, has been reported to have antimicrobial, antifungal, anti-inflammatory, antispasmodic, antipyretic, antitumoural and cicatrizing properties. This work studies supercritical fluid extraction (SFE to obtain volatile and non-volatile compounds from the aerial parts of Schinus molle L. and the influence of the process on the composition of the extracts. Experiments were performed in a pilot-scale extractor with a capacity of 1 L at pressures of 9, 10, 12, 15 and 20 MPa at 323.15 K. The volatile compounds were obtained by CO2 supercritical extraction with moderate pressure (9 MPa, whereas the non-volatile compounds were extracted at higher pressure (12 to 20 MPa. The analysis of the essential oil was carried out by GC-MS and the main compounds identified were sabinene, limonene, D-germacrene, bicyclogermacrene, and spathulenol. For the non-volatile extracts, the total phenolic content was determined by the Folin-Ciocalteau method. Moreover, one of the goals of this study was to compare the experimental data with the simulated yields predicted by a mathematical model based on mass transfer. The model used requires three adjustable parameters to predict the experimental extraction yield curves.

  6. Analysis of volatile compounds from Iberian hams: a review

    Directory of Open Access Journals (Sweden)

    Narváez-Rivas, M.

    2012-10-01

    Full Text Available This article provides information on the study of the volatile compounds in raw and dry-cured Iberian hams. Different volatile compounds are identified and studies carried out by different authors are presented. This article reviews the analytical methods that have been used to determine the different volatiles of these samples. Furthermore, all volatile compounds identified (a total of 411 volatiles have been collected in several tables according to different series of compounds: hydrocarbons, aldehydes, ketones, alcohols, esters and ethers, lactones, terpenes and chloride compounds, nitrogenous compounds, sulfur compounds and carboxylic acids. This review can be useful in subsequent research due to the complexity of the study.

    En este artículo se proporciona información sobre el estudio de los compuestos volátiles del jamón ibérico tanto fresco como curado. Se presentan los diferentes compuestos volátiles identificados por distintos autores. Además, se evalúan los métodos analíticos que han sido utilizados para determinar dichos compuestos volátiles en este tipo de muestras. Todos los compuestos identificados y descritos en esta revisión (un total de 411 compuestos volátiles han sido agrupados en diversas tablas de acuerdo a las diferentes familias a que pertenecen: hidrocarburos, aldehídos, cetonas, alcoholes, ésteres y éteres, lactonas, terpenos, compuestos halogenados, compuestos nitrogenados, compuestos de azufre y ácidos carboxílicos. Debido a la complejidad de este estudio, la presente revisión puede ser muy útil en investigaciones posteriores.

  7. Fast and simple screening for the simultaneous analysis of seven metabolites derived from five volatile organic compounds in human urine using on-line solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Chiang, Wen-Chieh; Chen, Chao-Yu; Lee, Ting-Chen; Lee, Hui-Ling; Lin, Yu-Wen

    2015-01-01

    Recently, the International Agency for Research on cancer classified outdoor air pollution and particulate matter from outdoor air pollution as carcinogenic to humans (IARC Group 1), based on sufficient evidence of carcinogenicity in humans and experimental animals and strong mechanistic evidence. In particular, a wide variety of volatile organic compounds (VOCs) are volatized or released into the atmosphere and can become ubiquitous, as they originate from many different natural and anthropogenic sources, such as paints, pesticides, vehicle exhausts, cooking fumes, and tobacco smoke. Humans may be exposed to VOCs through inhalation, ingestion, or dermal contact, which may increase the risk of leukemia, birth defects, neurocognitive impairment, and cancer. Therefore, the focus of this study was the development of a simple, effective and rapid sample preparation method for the simultaneous determination of seven metabolites (6 mercaptic acids+t,t-muconic acid) derived from five VOCs (acrylamide, 1,3-butadiene, acrylonitrile, benzene, and xylene) in human urine by using automated on-line solid-phase extraction (SPE) coupled with liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS). An aliquot of each diluted urinary sample was directly injected into an autosampler through a trap column to reduce contamination, and then the retained target compounds were eluted by back-flush mode into an analytical column for separation. Negative electrospray ionization tandem mass spectrometry was utilized for quantification. The coefficients of correlation (r(2)) for the calibration curves were greater than 0.995. Reproducibility was assessed by the precision and accuracy of intra-day and inter-day precision, which showed results for coefficient of variation (CV) that were low 0.9 to 6.6% and 3.7 to 8.5%, respectively, and results for recovery that ranged from 90.8 to 108.9% and 92.1 to 107.7%, respectively. The limits of detection (LOD) and limits of

  8. IN SITU MEASUREMENTS OF C2-C10 VOLATILE ORGANIC COMPOUNDS ABOVE A SIERRA NEVADA PONDEROSA PINE PLANTATION

    Science.gov (United States)

    A fully automated GC-FID system was designed and built to measure ambient concentrations of C2-C10 volatile organic compounds, including many oxygenated compounds, without using liquid cryogen. It was deployed at Blodgett Forest Research Station in Georgetown, CA USA, 38 deg 53' ...

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

    Science.gov (United States)

    Urbach, G

    1987-08-28

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

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

    Directory of Open Access Journals (Sweden)

    Chang-Bin Wei

    2012-06-01

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

  11. Volatile compounds present in traditional meat products (charqui and longaniza sausage in Chile

    Directory of Open Access Journals (Sweden)

    María Pía Gianelli

    2012-08-01

    Full Text Available The aim of this work was to identify and quantify the volatile compounds in five different commercial brands of charqui and longaniza sausages. Volatile compounds were extracted from some samples headspace using solid phase microextraction (SPME. The identification and quantification were made through the gas chromatography with a mass-selective detector (GS-MS. Fifty-four volatile compounds were identified in charqui samples and thirty-two volatile compounds in longaniza sausages. The chemical groups of the volatile compounds found in both the products were: aldehydes, alcohols, ketones, organic acids, furans, aromatic and aliphatic hydrocarbons. Significant differences were found (p<0.05 in the volatile compounds among the brands of longaniza and charqui. A characteristic volatile compounds profile was not found in the analyzed products. However, an important percentage of the volatile compounds in charqui came from the lipid oxidation. In the case of longanizas sausages, volatile compounds come mainly from the carbohydrates fermentation and spices.

  12. Methods in plant foliar volatile organic compounds research 1

    OpenAIRE

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel J.; Gauci, Vincent

    2015-01-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant–plant and plant–insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas...

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

    Science.gov (United States)

    Speciated volatile organic compounds (VOCs) and organic fine particulate matter (PM2.5) mass emission factors were determined from laboratory peat fire experiments. Peat samples originated from two wildlife reserves located near the coast of North Carolina, U.S. Gas and particula...

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

    Science.gov (United States)

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

  15. Volatile organic compounds of whole grain soft winter wheat

    Science.gov (United States)

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

  16. Modeling emissions of volatile organic compounds from silage

    Science.gov (United States)

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

  17. The emission of volatile compounds from leaf litter

    NARCIS (Netherlands)

    Derendorp, L.

    2012-01-01

    Leaf litter is available at the Earth’s surface in large quantities. During the decomposition of leaf litter, volatile compounds can be released into the atmosphere, where they potentially influence local air quality, atmospheric chemistry or the global climate. In this thesis the focus was on the e

  18. Development of volatile compounds in processed cheese during storage

    DEFF Research Database (Denmark)

    Sunesen, Lars Oddershede; Lund, Pia; Sørensen, J.

    2002-01-01

    The purpose of this work teas to study tire impact of storage conditions, such as light and temperature, on the development of volatile compounds to processed cheese. Cheese in glass containers was stored at 5, 20 or 37 degreesC in light or darkness for up to 1 yr. Dynamic headspace and gas...

  19. Volatile compounds released during ripening in Italian dried sausage

    DEFF Research Database (Denmark)

    Sunesen, Lars Oddershede; Dorigoni, V.; Zanardi, E.

    2001-01-01

    A commercial production was analysed at six stages during ripening. Water content, pH and bacterial counts were followed, and volatile compounds from sausages were extracted by dynamic headspace sampling and analysed by gas chromatography/mass spectrometry. Total concentrations of all classes inc...

  20. Qualitative analysis of volatile organic compounds on biochar

    Science.gov (United States)

    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...

  1. Volatile compounds released during ripening in Italian dried sausage

    DEFF Research Database (Denmark)

    Sunesen, Lars Oddershede; Dorigoni, V.; Zanardi, E.;

    2001-01-01

    A commercial production was analysed at six stages during ripening. Water content, pH and bacterial counts were followed, and volatile compounds from sausages were extracted by dynamic headspace sampling and analysed by gas chromatography/mass spectrometry. Total concentrations of all classes...

  2. The emission of volatile compounds from leaf litter

    NARCIS (Netherlands)

    Derendorp, L.|info:eu-repo/dai/nl/314016414

    2012-01-01

    Leaf litter is available at the Earth’s surface in large quantities. During the decomposition of leaf litter, volatile compounds can be released into the atmosphere, where they potentially influence local air quality, atmospheric chemistry or the global climate. In this thesis the focus was on the

  3. Bioactivity of volatile organic compounds produced by Pseudomonas tolaasii

    Directory of Open Access Journals (Sweden)

    Pietro eLo Cantore

    2015-10-01

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

  4. Characterization of volatile aroma compounds in different brewing barley cultivars.

    Science.gov (United States)

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

    2015-03-30

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

  5. Determination of Volatile Organic Compounds in Selected Strains of Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Ivan Milovanović

    2015-01-01

    Full Text Available Microalgal biomass can be used in creating various functional food and feed products, but certain species of microalgae and cyanobacteria are known to produce various compounds causing off-flavour. In this work, we investigated selected cyanobacterial strains of Spirulina, Anabaena, and Nostoc genera originating from Serbia, with the aim of determining the chemical profile of volatile organic compounds produced by these organisms. Additionally, the influence of nitrogen level during growth on the production of volatile compounds was investigated for Nostoc and Anabaena strains. In addition, multivariate techniques, namely, principal component analysis (PCA and hierarchical cluster analysis (HCA, were used for making distinction among different microalgal strains. The results show that the main volatile compounds in these species are medium chain length alkanes, but other odorous compounds such as 2-methylisoborneol (0.51–4.48%, 2-pentylfuran (0.72–8.98%, β-cyclocitral (0.00–1.17%, and β-ionone (1.15–2.72% were also detected in the samples. Addition of nitrogen to growth medium was shown to negatively affect the production of 2-methylisoborneol, while geosmin was not detected in any of the analyzed samples, which indicates that the manipulation of growth conditions may be useful in reducing levels of some unwanted odor-causing components.

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

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-03-10

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

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

    Directory of Open Access Journals (Sweden)

    Milena Šetka

    2017-03-01

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

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

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Hubálek, Jaromír

    2017-01-01

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

  9. QSRR Study of GC Retention Indices of Volatile Compounds Emitted from Mosla chinensis Maxim by Multiple Linear Regression%QSRR Study of GC Retention Indices of Volatile Compounds Emitted from Mosla chinensis Maxim by Multiple Linear Regression

    Institute of Scientific and Technical Information of China (English)

    曹慧; 李祖光; 陈小珍

    2011-01-01

    The volatile compounds emitted from Mosla chinensis Maxim were analyzed by headspace solid-phase micro- extraction (HS-SPME) and headspace liquid-phase microextraction (HS-LPME) combined with gas chromatography-mass spectrometry (GC-MS). The main volatiles from Mosla chinensis Maxim were studied in this paper. It can be seen that 61 compounds were separated and identified. Forty-nine volatile compounds were identified by SPME method, mainly including myrcene, a-terpinene, p-cymene, (E)-ocimene, thymol, thymol acetate and (E)-fl-farnesene. Forty-five major volatile compounds were identified by LPME method, including a-thujene, a-pinene, camphene, butanoic acid, 2-methylpropyl ester, myrcene, butanoic acid, butyl ester, a-terpinene, p-cymene, (E)-ocimene, butane, 1,1-dibutoxy-, thymol, thymol acetate and (E)-fl-farnesene. After analyzing the volatile compounds, multiple linear regression (MLR) method was used for building the regression model. Then the quantitative structure-retention relationship (QSRR) model was validated by predictive-ability test. The prediction results were in good agreement with the experimental values. The results demonstrated that headspace SPME-GC-MS and LPME-GC-MS are the simple, rapid and easy sample enrichment technique suitable for analysis of volatile compounds. This investigation provided an effective method for predicting the retention indices of new compounds even in the absence of the standard candidates.

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

    Science.gov (United States)

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

    2014-10-15

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

  11. 75 FR 2090 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound...

    Science.gov (United States)

    2010-01-14

    ... Organic Compound Automobile Refinishing Rules for Indiana AGENCY: Environmental Protection Agency (EPA... relations, Nitrogen dioxide, Ozone, Reporting and recordkeeping requirements, Volatile organic compounds... Plan (SIP). These rule revisions extend the applicability of Indiana's approved volatile...

  12. Characteristics of volatile compounds removal in biogas slurry of pig manure by ozone oxidation and organic solvents extraction

    Institute of Scientific and Technical Information of China (English)

    Yujun Wang; Lianshuang Feng; Xiaosong Zhao; Xiulan Ma; Jingmin Yang; Huiqing Liu; Sen Dou

    2013-01-01

    Biogas slurry is not suitable for liquid fertilizer due to its high amounts of volatile materials being of complicated composition and peculiar smell.In order to remove volatiles from biogas slurry efficiently,the dynamic headspace and gas chromatography-mass spectrometry were used to clear the composition of volatiles.Nitrogen stripping and superfluous ozone were also used to remove volatiles from biogas slurry.The results showed that there were 21 kinds of volatile compounds in the biogas slurry,including sulfur compounds,organic amines,benzene,halogen generation of hydrocarbons and alkanes,some of which had strong peculiar smell.The volatile compounds in biogas slurry can be removed with the rate of 53.0% by nitrogen stripping and with rate of 81.7% by the oxidization and stripping of the superfluous ozone.On this basis,the removal rate of the volatile compounds reached 99.2%by chloroform and n-hexane extraction,and almost all of odor was eliminated.The contents of some dissolved organic compounds decreased obviously and however main plant nutrients had no significant change in the biogas slurry after being treated.

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

    Science.gov (United States)

    Justesen, Ulrik Stenz

    2016-12-12

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

  14. Analytical methods for volatile compounds in wheat bread.

    Science.gov (United States)

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

    2016-01-08

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

  15. 78 FR 11119 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of trans

    Science.gov (United States)

    2013-02-15

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

  16. Volatile organic compound optical fiber sensors: a review

    OpenAIRE

    Arregui, Francisco J.; Candido Bariain; Matias, Ignacio R; Cesar Elosua

    2006-01-01

    Volatile organic compound (VOC) detection is a topic of growing interest with applications in diverse fields, ranging from environmental uses to the food or chemical industries. Optical fiber VOC sensors offering new and interesting properties which overcame some of the inconveniences found on traditional gas sensors appeared over two decades ago. Thanks to its minimum invasive nature and the advantages that optical fiber offers such as light weight, passive nature, low attenuation and the...

  17. Highly sensitive electromembrane extraction for the determination of volatile organic compound metabolites in dried urine spot.

    Science.gov (United States)

    Suh, Joon Hyuk; Eom, Han Young; Kim, Unyong; Kim, Junghyun; Cho, Hyun-Deok; Kang, Wonjae; Kim, Da Som; Han, Sang Beom

    2015-10-16

    Electromembrane extraction coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for determination of ten volatile organic compound metabolites in dried urine spot samples. The dried urine spot approach is a convenient and economical sampling method, wherein urine is spotted onto a filter paper and dried. This method requires only a small amount of sample, but the analysis sometimes suffers from low sensitivity, which can lead to analytical problems in the detection of minor components in samples. The newly developed dried urine spot analysis using electromembrane extraction exhibited improved sensitivity and extraction, and enrichment of the sample was rapidly achieved in one step by applying an electric field. Aliquots of urine were spotted onto Bond Elut DMS cards and dried at room temperature. After drying, the punched out dried urine spot was eluted with water. Volatile organic compound metabolites were extracted from the sample through a supported liquid membrane into an alkaline acceptor solution inside the lumen of a hollow fiber with the help of an electric potential. The optimum extraction conditions were determined by using design of experiments (fractional factorial design and response surface methodology). Satisfactory sensitivity was achieved and the limits of quantification (LOQ) obtained were lower than the regulatory threshold limits. The method was validated by assessing the linearity, precision, accuracy, recovery, reproducibility, stability, and matrix effects. The results were acceptable, and the developed method was successfully applied to biological exposure monitoring of volatile organic compound metabolites in fifty human urine samples.

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

    Science.gov (United States)

    Bennett, Joan W; Inamdar, Arati A

    2015-09-22

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

  19. Are Some Fungal Volatile Organic Compounds (VOCs Mycotoxins?

    Directory of Open Access Journals (Sweden)

    Joan W. Bennett

    2015-09-01

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

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

    Science.gov (United States)

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

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

  1. Rapid changes of induced volatile organic compounds in Pinus massoniana

    Institute of Scientific and Technical Information of China (English)

    REN Qin; JIN Youju; HU Yongiian; CHEN Huajun; LI Zhenyu

    2007-01-01

    Using the thermal-desorption cold trap gas chromatography/mass spectrometer(TCT-GC-MS)technique,the composition and relative contents of volatile compounds were analyzed in undamaged(control),insect-damaged(ID)and artificially-damaged(AD)leaves ofPinus massoniana in field at different times and levels of damage.Results showed that although volatile substances were highly released earlier in AD leaves plants,they were significantly less abundant in AD than in ID leaves treatments.Also,the damage level considerably influenced the changes of induced volatile products from leaves.Compared with the control,the emission rate of camphene,β-pinene,phellandrene,caryophyllene and(E)farnesene was high after 1 h in 25%-40% ID-affected leaves,whereas that of tricyclene,myrcene,camphene,β-Pinene,phellandrene and caryophyllene reached its maximum after 24 h in 60%-75% D-affected leaves.In the same manner,some volatile compounds in the AD leaves treatment displayed their peaks just after 1 h,but others after 24 h.The AD and ID leaves at the damage level of 25%-40% did not exhibit an obvious regularity with time;however,in 60%- 75% AD leaves,peaks of volatile substances were attained after 1 or 2 h.Our results also showed that the relative content ofβ-pinene increased and was higher in damaged than control plants,β-pinene plays an important role in inducing the insect resistance of P.massoniana trees.

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

    Science.gov (United States)

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

    2016-11-15

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

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Increasing the isolated quantities and purities of volatile compounds by using a triple Deans-switch multidimensional preparative gas chromatographic system with an apolar-wax-ionic liquid stationary-phase combination.

    Science.gov (United States)

    Sciarrone, Danilo; Pantò, Sebastiano; Ragonese, Carla; Tranchida, Peter Quinto; Dugo, Paola; Mondello, Luigi

    2012-08-21

    A novel preparative-scale triple gas chromatographic system, equipped with three Deans-switch devices, is herein described. The isolation of volatile compounds was achieved by using a lab-made collection system. Considerations are made on the possibility to inject high volumes of neat sample, maintaining, at the same time, high resolution levels. The degree of recovery of a series of compounds, characterized by a differing volatility, is also reported. In this respect, different collection conditions were evaluated, namely, the presence (or not) of packing material as well as CO(2) cooling, in various combinations. Finally, the interconnected features, that is time requirements and the isolation of "acceptable" analyte quantities (e.g., milligram level for NMR characterization), are related to parameters such as analyte concentration, injected volume, collection conditions, and number of GC runs. The results herein reported will demonstrate the need for a high-resolution GC step, prior to analyte collection, in the prep-GC analysis of complex samples.

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

    Science.gov (United States)

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

    2017-05-02

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

  6. [Emission model of volatile organic compounds from materials used indoors].

    Science.gov (United States)

    Han, K

    1998-11-30

    Various materials, such as wall-paper, floor-wax, paint, multicolor wall-coat, air freshener and mothball were experimented in a simulated test chamber under constant selected temperature, humidity and air exchange rate. The relation between the total VOCs concentration and time was regressed by four emission models and the surface emission rate was calculated. The regressed results indicated the similarity among four emission models for the liquid materials with volatile-solvent such as paint and multicolor wall-coat. But for low volatile solid materials, such as wall-paper, floor-wax, mothball, the sink model and the empirical model were better than the dilution model and vapor pressure model. Only for air freshener, it was improper to the total VOCs concentration as a parameter.

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

    Science.gov (United States)

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

    2016-12-01

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

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

    Science.gov (United States)

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

    2011-12-01

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

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

    Science.gov (United States)

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

    2005-08-01

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

  10. Molecular Beam Studies of Volatile Liquids and Fuel Surrogates Using Liquid Microjets

    Science.gov (United States)

    2014-12-18

    Molecular Beam Studies of Volatile Liquids and Fuel Surrogates Using Liquid Microjets Gilbert Nathanson, Department of Chemistry University of...alter the dynamics of evaporation from the commercial jet fuel Jet A. These results are outlined below. Exploring Fuels in Vacuum using Liquid ...hydrocarbon liquids inside a vacuum chamber. These jets, narrower than a human hair, are typically 10 – 40 µm in diameter. Their small surface area and

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-07

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

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

    Science.gov (United States)

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

    2010-12-01

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

  13. Volatile organic compound emissions from Larrea tridentata (creosotebush

    Directory of Open Access Journals (Sweden)

    J. Ortega

    2010-07-01

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

  14. Volatile organic compound emissions from Larrea tridentata (creosotebush

    Directory of Open Access Journals (Sweden)

    A. Guenther

    2010-12-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

  16. Fast analysis of volatile organic compounds and disinfection by-products in drinking water using solid-phase microextraction-gas chromatography/time-of-flight mass spectrometry.

    Science.gov (United States)

    Niri, Vadoud H; Bragg, Leslie; Pawliszyn, Janusz

    2008-08-08

    A fast method was developed for the extraction and analysis of volatile organic compounds, including disinfection by-products (DBPs), with headspace solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) techniques. A GC/time-of-flight (TOF)-MS instrument, which had fast acquisition rates and powerful deconvolution software, was used. Under optimum conditions total runtime was 45s. Volatile organic compounds (VOCs), including purgeable A and B compounds (listed in US Environmental Protection Agency method 624), were identified in standard water samples. Extraction times were 1min for more volatile compounds and 2min for less volatile compounds. The method was applied to the analysis of water samples treated under different disinfection processes and the results were compared with those from a liquid-liquid extraction method.

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

    Science.gov (United States)

    Rathbun, R.E.

    2000-01-01

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

  18. Simultaneous Microwave Extraction and Separation of Volatile and Non-Volatile Organic Compounds of Boldo Leaves. From Lab to Industrial Scale

    Directory of Open Access Journals (Sweden)

    Loïc Petigny

    2014-04-01

    Full Text Available Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC from non-Volatile Organic Compounds (NVOC of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant.

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

    Science.gov (United States)

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

    2012-01-01

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

  20. Synthesis of Carbon Nanotubes and Volatile Organic Compounds Detection

    Directory of Open Access Journals (Sweden)

    Sobri S.

    2016-01-01

    Full Text Available In this work, the adsorption effect of volatile organic compounds (chloroacetophenone, acetonitrile and hexane towards the change of resistance of CNTs pellet as sensor signal was investigated. CNTs used in this research were synthesized using Floating Catalyst – Chemical Vapor Deposition (FC-CVD method in optimum condition. The synthesized CNTs were characterized using Scanning Electron Microscopy (SEM, Transmission Electron Microscopy (TEM and Raman Spectroscopy. The variation of resistance changes towards the tested gases were recorded using a multimeter. CNTs sensor pellet showed good responses towards the tested gases, however, the sensitivity, response time and recovery time of sensor pellet need to be optimized.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    The biogenic volatile organic compound (BVOC) emissions from plants impact atmosphere and climate. The species-specific emissions, and thereby the atmospheric impact, of many plant species are still unknown. Knowledge of BVOC emission from arctic plants is particularly limited. The vast area...... and relatively high leaf temperature give the Arctic potential for emissions that cannot be neglected. This field study aimed to elucidate the BVOC emission profiles for four common arctic plant species in their natural environment during the growing season. BVOCs were sampled from aboveground parts of Empetrum...

  2. The sampling apparatus of volatile organic compounds for wood composites

    Institute of Scientific and Technical Information of China (English)

    SHENJun; ZHAOLin-bo; LIUYu

    2005-01-01

    Terpenes, aldehydes, ketones, benzene, and toluene are the important volatile organic compounds (VOCs) emitted from wood composites. A sampling apparatus of VOCs for wood composites was designed and manufactured by Northeast Forestry University in China.The concentration of VOCs derived from wood based materials, such as flooring, panel wall, finishing, and furniture can be sampled in a small stainless steel chambers. A protocol is also developed in this study to sample and measure the new and representative specimens. Preliminary research showed that the properties of the equipment have good stability. The sort and the amount of different components can be detected from it. The apparatus is practicable.

  3. Review on Volatile Organic Compounds Emission from Wood Composites

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; YU Yaoming; SHEN Jun; LIU Ming

    2006-01-01

    The problem of indoor air quality (IAQ) is mainly caused by the volatile organic compounds (VOC) emission from the wood-based composites. As a material for decoration, furniture manufacturing or building, wood-based composite is one of the sources of VOC emissions. Most of them are formaldehyde, terpene, ketone and benzene. The paper reviews on VOC emission of wood-based composites at home and abroad, including the source of the VOC, its impacts on IAQ, its emission during processing and using, the usual sampling and analyse methods of VOC in different conditions. Meanwhile, main problems existed in the past researches are summarized and some suggestions are put forward.

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

    Science.gov (United States)

    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...

  5. Turbulence effects on volatilization rates of liquids and solutes

    Science.gov (United States)

    Lee, J.-F.; Chao, H.-P.; Chiou, C.T.; Manes, M.

    2004-01-01

    Volatilization rates of neat liquids (benzene, toluene, fluorobenzene, bromobenzene, ethylbenzene, m-xylene, o-xylene, o-dichlorobenzene, and 1-methylnaphthalene) and of solutes (phenol, m-cresol, benzene, toluene, ethylbenzene, o-xylene, and ethylene dibromide) from dilute water solutions have been measured in the laboratory over a wide range of air speeds and water-stirring rates. The overall transfer coefficients (KL) for individual solutes are independent of whether they are in single- or multi-solute solutions. The gas-film transfer coefficients (kG) for solutes in the two-film model, which have hitherto been estimated by extrapolation from reference coefficients, can now be determined directly from the volatilization rates of neatliquids through anew algorithm. The associated liquid-film transfer coefficients (KL) can then be obtained from measured KL and kG values and solute Henry law constants (H). This approach provides a novel means for checking the precision of any kL and kG estimation methods for ultimate prediction of KL. The improved kG estimation enables accurate K L predictions for low-volatility (i.e., low-H) solutes where K L and kGH are essentially equal. In addition, the prediction of KL values for high-volatility (i.e., high-H) solutes, where KL ??? kL, is also improved by using appropriate reference kL values.

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

    Science.gov (United States)

    Aprea, Eugenio; Biasioli, Franco; Gasperi, Flavia

    2015-01-30

    Volatile compounds play a key role in the formation of the well-recognized and widely appreciated raspberry aroma. Studies on the isolation and identification of volatile compounds in raspberry fruit (Rubus idaeus L.) are reviewed with a focus on aroma-related compounds. A table is drawn up containing a comprehensive list of the volatile compounds identified so far in raspberry along with main references and quantitative data where available. Two additional tables report the glycosidic bond and enantiomeric distributions of the volatile compounds investigated up to now in raspberry fruit. Studies on the development and evolution of volatile compounds during fruit formation, ripening and senescence, and genetic and environmental influences are also reviewed. Recent investigations showing the potential role of raspberry volatile compounds in cultivar differentiation and fruit resistance to mold disease are reported as well. Finally a summary of research done so far and our vision for future research lines are reported.

  7. Volatile Compounds of Raspberry Fruit: From Analytical Methods to Biological Role and Sensory Impact

    Directory of Open Access Journals (Sweden)

    Eugenio Aprea

    2015-01-01

    Full Text Available Volatile compounds play a key role in the formation of the well-recognized and widely appreciated raspberry aroma. Studies on the isolation and identification of volatile compounds in raspberry fruit (Rubus idaeus L. are reviewed with a focus on aroma-related compounds. A table is drawn up containing a comprehensive list of the volatile compounds identified so far in raspberry along with main references and quantitative data where available. Two additional tables report the glycosidic bond and enantiomeric distributions of the volatile compounds investigated up to now in raspberry fruit. Studies on the development and evolution of volatile compounds during fruit formation, ripening and senescence, and genetic and environmental influences are also reviewed. Recent investigations showing the potential role of raspberry volatile compounds in cultivar differentiation and fruit resistance to mold disease are reported as well. Finally a summary of research done so far and our vision for future research lines are reported.

  8. Non-Equilibrium Gibbs' Criterion for Completely Wetting Volatile Liquids

    CERN Document Server

    Tsoumpas, Yannis; Galvagno, Mariano; Rednikov, Alexey; Ottevaere, Heidi; Thiele, Uwe; Colinet, Pierre

    2014-01-01

    During the spreading of a liquid over a solid substrate, the contact line can stay pinned at sharp edges until the contact angle exceeds a critical value. At (or sufficiently near) equilibrium, this is known as Gibbs' criterion. Here, we show both experimentally and theoretically that for completely wetting volatile liquids there also exists a dynamically-produced critical angle for depinning, which increases with the evaporation rate. This suggests that one may introduce a simple modification of the Gibbs' criterion for (de)pinning, that accounts for the non-equilibrium effect of evaporation.

  9. Biogenic Emissions of Volatile Organic Compounds by Urban Forests

    Institute of Scientific and Technical Information of China (English)

    CENTRITTOMauro; LIUShirong; LORETOFrancesco

    2005-01-01

    All plants emit a wide range of volatile compounds, the so-called biogenic volatile organic compounds (BVOC). BVOC emissions have received increased scientific attention in the last two decades because they may profoundly influence the chemical and physical properties of the atmosphere, and may modulate plant tolerance to heat, pollutants, oxidative stress and abiotic stresses, and affect plant-plant and plant-insect interactions. Urban forestry may have a high impact on atmospheric composition, air quality, environment,and quality of life in urban areas. However, few studies have been carried out where the emission of BVOC could have important consequence for the quality of air and contribute to pollution episodes. A screening of BVOC emission by the mixed stand constituting urban forests is therefore required if emissions are to be reliably predicted. Monitoring the emission rates simultaneously with measurements of air quality, plant physiology and micrometeorology on selected urban forests, will allow detailed quantitative information on the inventory of BVOC emissions by urban vegetation to be compiled. This information will make it possible to propose an innovative management of urban vegetation in cities characterised by heavy emissions of anthropogenic pollutants, aiming at the abatement of BVOC emissions through the introduction or selection of non-BVOC emitting species in urban areas subjected to pollution episodes and in the new afforestation areas covering peri-urban parks, green belts and green corridors between peri-urban rural areas and the conurbations.

  10. Evaporation of volatile organic compounds from human skin in vitro.

    Science.gov (United States)

    Gajjar, Rachna M; Miller, Matthew A; Kasting, Gerald B

    2013-08-01

    The specific evaporation rates of 21 volatile organic compounds (VOCs) from either human skin or a glass substrate mounted in modified Franz diffusion cells were determined gravimetrically. The diffusion cells were positioned either on a laboratory bench top or in a controlled position in a fume hood, simulating indoor and outdoor environments, respectively. A data set of 54 observations (34 skin and 20 glass) was assembled and subjected to a correlation analysis employing 5 evaporative mass transfer relationships drawn from the literature. Models developed by Nielsen et al. (Prediction of isothermal evaporation rates of pure volatile organic compounds in occupational environments: a theoretical approach based on laminar boundary layer theory. Ann Occup Hyg 1995;39:497-511.) and the U.S. Environmental Protection Agency (Peress, Estimate evaporative losses from spills. Chem Eng Prog 2003; April: 32-34.) were found to be the most effective at correlating observed and calculated evaporation rates under the various conditions. The U.S. EPA model was selected for further use based on its simplicity. This is a turbulent flow model based only on vapor pressure and molecular weight of the VOC and the effective air flow rate u. Optimum values of u for the two laboratory environments studied were 0.23 m s(-1) (bench top) and 0.92 m s(-1) (fume hood).

  11. Emission of Biogenic Volatile Organic Compounds in the Arctic

    DEFF Research Database (Denmark)

    Lindwall, Frida

    Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants,......, arctic BVOC emissions will become more important for the global BVOC budget as well as for the regional climate due to the positive and negative climate warming feedbacks.......Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants...... growing seasons, low temperatures and low statured plants, occurs at twice the speed of the global average. Changes in temperature and precipitation patterns have consequences for soil, plant species distribution, plant biomass and reproductive success. Emission and production of BVOCs are temperature...

  12. EPA Method 8321B (SW-846): Solvent-Extractable Nonvolatile Compounds by High Performance Liquid Chromatography-Thermospray-Mass Spectrometry (HPLC-TS-MS) or Ultraviolet (UV) Detection

    Science.gov (United States)

    Method 8321B describes procedures for preparation and analysis of solid, aqueous liquid, drinking water and wipe samples using high performance liquid chromatography and mass spectrometry for extractable non-volatile compounds.

  13. Volatile organic compounds emissions from gasoline and diesel powered vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Mugica, V [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico); Vega, E; Sanchez, G; Reyes, E; Arriaga, J. L [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Chow, J; Watson, J; Egami, R [Desert Research Institute, Reno, NV (United States)

    2001-01-01

    In this research, volatile organic compound emissions were characterized from gasoline and diesel vehicles. Sampling campaigns in the Metropolitan Area of Mexico City were designed and carried out in tunnels, crossroads, and truck and bus terminals. The samples were analyzed with gas chromatography getting more than 250 different compounds, being more or less 60 of them the 80% of all the emissions. The most abundant are the two carbon compounds, as a result of the combustion, and compounds related to fuels compositions, like isopentane, xylenes, toluene among others. The profiles obtained in tunnels and crossroads were very similar with the exception of the 3 and 4 carbon compounds, which were found in bigger proportion in the profiles at crossroads. This may probably be due to the blend with the ambient air. The profiles corresponding to trucks and buses have a smaller content of two carbon compounds and a bigger content of xylenes, toluene and ethylbenzene. The variations in the proportions of the compounds allow differentiating the profiles of vehicles using gasoline and diesel. [Spanish] En este trabajo se caracterizaron las emisiones de compuestos organicos volatiles provenientes de vehiculos a gasolina y a diesel. Para ello, se disenaron diversas campanas de muestreo en la zona Metropolitana de la Ciudad de Mexico, en tuneles, cruceros y estaciones de camiones de carga y autobuses. Las muestras se analizaron con cromatografia, de gases obteniendose mas de 250 compuestos distintos, de los cuales aproximadamente 60 corresponden a mas del 80% de las emisiones. Los compuestos mas abundantes son los de dos carbonos, resultado de la combustion, y 4 carbonos que se encontraron en mayor proporcion en los perfiles de cruceros, lo cual se debe probablemente a la mezcla con el aire ambiente. Los perfiles correspondientes a camiones de carga y autobuses tienen un menor contenido de compuestos de dos carbonos y un mayor contenido de xilenos, tolueno y etilbenceno. Estas

  14. Anti-Salmonella Activity of Volatile Compounds of Vietnam Coriander.

    Science.gov (United States)

    Fujita, Ken-Ichi; Chavasiri, Warinthorn; Kubo, Isao

    2015-07-01

    Essential oil derived from the fresh leaves of Polygonum odoratum Lour was tested for their effects on a foodborne bacterium Salmonella choleraesuis subsp. choleraesuis ATCC 35640 using a broth dilution method. This essential oil showed a significant antibacterial activity against S. choleraesuis at the concentration of 200 µg/mL. Twenty-five volatile compounds were characterized from this essential oil by GC-MS, and aldehyde compounds were found abundant and accounted for more than three-fourths of the essential oil. Among the compounds characterized, dodecanal (C12 ) was the most abundant (55.5%), followed by decanal (C10 ) (11.6%). Both alkanals were effective against S. choleraesuis with the minimum growth inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 100 µg/mL. The most potent antibacterial activity against this bacterium was found with two minor compounds, dodecanol (lauryl alcohol) and 2E-dodecenal, both with each MBC of 6.25 µg/mL. Their primary antibacterial action against S. choleraesuis provably comes from their ability to function as nonionic surface-active agents (surfactants), disrupting the native function of integral membrane proteins nonspecifically. Thus, the antibacterial activity is mediated by biophysical processes. In the case of 2E-alkenals, a biochemical mechanism is also somewhat involved, depending on their alkyl chain length.

  15. Recovery of volatile fruit juice aroma compounds by membrane technology

    DEFF Research Database (Denmark)

    Bagger-Jørgensen, Rico; Meyer, Anne S.; Pinelo, Manuel

    2011-01-01

    The influence of temperature (10–45°C), feed flow rate (300–500L/h) and sweeping gas flow rate (1.2–2m3/h) on the recovery of berry fruit juice aroma compounds by sweeping gas membrane distillation (SGMD) was examined on an aroma model solution and on black currant juice in a lab scale membrane...... (Cpermeate/Cfeed) of the aroma compounds. At 45°C the most volatile and hydrophobic aroma compounds obtained the highest concentration factors: 12.1–9.3 (black currant juice) and 17.2–12.8 (model solution). With black currant juice a volume reduction of 13.7% (vol.%) at 45°C, 400L/h, resulted in an aroma...... the degradation of anthocyanins and polyphenolic compounds in the juice. Industrial relevanceHigh temperature evaporation is the most widely used industrial technique for aroma recovery and concentration of juices, but membrane distillation (MD) may provide for gentler aroma stripping and lower energy consumption...

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

    NARCIS (Netherlands)

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

    2016-01-01

    The formation of volatile compounds in Turkish Divle Cave cheese produced in 3 different dairy farms was determined during production and ripening, revealing 110 compounds including acids, alcohols, ketones, esters, and terpenes. The presence and concentration of these volatile compounds varied betw

  17. Influence of ventilation type in volatile organic compounds exposure: poultry case

    OpenAIRE

    Viegas, Susana; Monteiro, ANA; Manteigas, Vítor; Carolino, Elisabete; Viegas, Carla

    2012-01-01

    Agricultural workers especially poultry farmers are at increased risk of occupational respiratory diseases. Epidemiological studies showed increased prevalence of respiratory symptoms and adverse changes in pulmonary function parameters in poultry workers. In poultry production volatile organic compounds (VOCs) presence can be due to some compounds produced by molds that are volatile and are released directly into the air. These are known as microbial volatile organic compounds (MVOCs). Be...

  18. Sensory Profiles and Volatile Compounds of Wheat Species, Landraces and Modern Varieties

    DEFF Research Database (Denmark)

    Starr, Gerrard

    ). Seventy two volatile compounds were identified in the grain of 81 wheat varieties (Paper II). Out of these, 7 selected wheat volatile compounds were significantly varied among 14 wheat varieties, indicating huge variation in volatile compound profiles among wheat varieties. Multivariate analysis showed...... that several wheat samples retained their configuration of distribution throughout the sensory tests. The same varieties also retained the same distribution configuration when analysed for volatile compounds which could link volatile profiles to sensory evaluation results (Papers II and III). Landraces were...... distinguishable from modern varieties and varieties from Austria could be distinguished from Danish, French and British varieties based on volatile profiles. This suggests that wheat volatile composition has genetic causes. The results in this study provide a strong case that there is wide variation among wheat...

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

    Science.gov (United States)

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

    2009-01-01

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

  20. Development of novel biofilters for treatment of volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, D.F. [Environmental Protection Agency, Cincinnati, OH (United States). National Risk Management Research Lab.; Govind, R. [Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering

    1995-12-31

    Biofiltration involves contacting a contaminated gas stream with immobilized microorganisms in a contactor to biodegrade the contaminants. It is emerging as an attractive technology for removing low concentrations (i.e., less than 800 ppmv) of volatile organic chemicals (VOCs) from air. Compared with other technologies, biofiltration fully mineralizes the contaminants, is inexpensive and reliable, and requires no posttreatment. In the study described in this paper, four types of media consisting of porous ceramic monoliths with several straight passages were studied to determine the effects of adsorptive and nonadsorptive media on biofilter startup time, dynamic response to step changes in inlet substrate concentration, biofilm adherence, and overall VOC-removal efficiency. Volatile compounds studied were benzene, toluene, ethylbenzene, m-xylene, and o-xylene. Adsorbing media such as activated carbon, when compared with nonadsorbing media such as ceramic, exhibit faster biofilter startup, are more stable to dynamic changes in inlet concentration, and attain higher VOC-removal efficiencies due to better adherence of biofilm on media surfaces.

  1. First Characterisation of Volatile Organic Compounds Emitted by Banana Plants.

    Science.gov (United States)

    Berhal, Chadi; De Clerck, Caroline; Fauconnier, Marie-Laure; Levicek, Carolina; Boullis, Antoine; Kaddes, Amine; Jijakli, Haïssam M; Verheggen, François; Massart, Sébastien

    2017-05-16

    Banana (Musa sp.) ranks fourth in term of worldwide fruit production, and has economical and nutritional key values. The Cavendish cultivars correspond to more than 90% of the production of dessert banana while cooking cultivars are widely consumed locally around the banana belt production area. Many plants, if not all, produce Volatile Organic Compounds (VOCs) as a means of communication with their environment. Although flower and fruit VOCs have been studied for banana, the VOCs produced by the plant have never been identified despite their importance in plant health and development. A volatile collection methodology was optimized to improve the sensitivity and reproducibility of VOCs analysis from banana plants. We have identified 11 VOCs for the Cavendish, mainly (E,E)-α-farnesene (87.90 ± 11.28 ng/μl), methyl salicylate (33.82 ± 14.29) and 6-methyl-5-hepten-2-one (29.60 ± 11.66), and 14 VOCs for the Pacific Plantain cultivar, mainly (Z,E)-α-farnesene (799.64 ± 503.15), (E,E)-α-farnesene (571.24 ± 381.70) and (E) β ocimene (241.76 ± 158.49). This exploratory study paves the way for an in-depth characterisation of VOCs emitted by Musa plants.

  2. Biofiltration for control of volatile organic compounds (VOCS)

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, D.F. [Environmental Protection Agency, Cincinnati, OH (United States); Govind, R. [Univ. of Cincinnati, OH (United States)

    1995-10-01

    Air biofiltration is a promising technology for control of air emissions of biodegradable volatile organic compounds (VOCs). In conjunction with vacuum extraction of soils or air stripping of ground water, it can be used to mineralize VOCs removed from contaminated soil or groundwater. The literature describes three major biological systems for treating contaminated air bioscrubbers, biotrickling filters and biofilters. Filter media can be classified as: bioactive fine or irregular particulates, such as soil, peat, compost or mixtures of these materials; pelletized, which are randomly packed in a bed; and structured, such as monoliths with defined or variable passage size and geometry. The media can be made of sorbing and non-absorbing materials. Non-bioactive pelletized and structured media require recycled solutions of nutrients and buffer for efficient microbial activity and are thus called biotrickling filters. Extensive work has been conducted to improve biofiltration by EPA`s Risk Reduction Engineering Laboratory and the University of Cincinnati in biofilters using pelletized and structured media and improved operational approaches. Representative VOCs in these studies included compounds with a range of aqueous solubilities and octanol-water partition coefficients. The compounds include iso-pentane, toluene, methylene chloride, trichloroethylene (TCE), ethyl benzene, chlorobenzene and perchloroethylene (PCE) and alpha ({alpha}-) pinene. Comparative studies were conducted with peat/compost biofilters using isopentane and {alpha}-pinene. Control studies were also conducted to investigate adsorption/desorption of contaminants on various media using mercuric chloride solution to insure the absence of bioactivity.

  3. Methods in plant foliar volatile organic compounds research.

    Science.gov (United States)

    Materić, Dušan; Bruhn, Dan; Turner, Claire; Morgan, Geraint; Mason, Nigel; Gauci, Vincent

    2015-12-01

    Plants are a major atmospheric source of volatile organic compounds (VOCs). These secondary metabolic products protect plants from high-temperature stress, mediate in plant-plant and plant-insect communication, and affect our climate globally. The main challenges in plant foliar VOC research are accurate sampling, the inherent reactivity of some VOC compounds that makes them hard to detect directly, and their low concentrations. Plant VOC research relies on analytical techniques for trace gas analysis, usually based on gas chromatography and soft chemical ionization mass spectrometry. Until now, these techniques (especially the latter one) have been developed and used primarily by physicists and analytical scientists, who have used them in a wide range of scientific research areas (e.g., aroma, disease biomarkers, hazardous compound detection, atmospheric chemistry). The interdisciplinary nature of plant foliar VOC research has recently attracted the attention of biologists, bringing them into the field of applied environmental analytical sciences. In this paper, we review the sampling methods and available analytical techniques used in plant foliar VOC research to provide a comprehensive resource that will allow biologists moving into the field to choose the most appropriate approach for their studies.

  4. [Ion mobility spectrometry for the isomeric volatile organic compounds].

    Science.gov (United States)

    Han, Hai-yan; Jia, Xian-de; Huang, Guo-dong; Wang, Hong-mei; Li, Jian-quan; Jin, Shun-ping; Jiang, Hai-he; Chu, Yan-nan; Zhou, Shi-kang

    2007-10-01

    Ion mobility spectrometry (IMS) is based on determining the drift velocities, which the ionized sample molecules attain in the weak electric field of a drift tube at atmospheric pressure. The drift behavior can be affected by structural differences of the analytes, so that ion mobility spectrometry has the ability to separated isomeric compounds. In the present article, an introduction to IMS is given, followed by a description of the instrument used for the experiments to differentiate isomeric compounds. Positive ion mobility spectras of three kinds of isomeric volatile organic compounds were studied in a homemade high-resolution IMS apparatus with a discharge ionization source. The study includes the differences in the structure of carbon chain, the style of function group, and the position of function group. The reduced mobility values were determined, which are in very good agreement with the previously reported theoretical values using neural network theory. The influence of the structural features of the substances and including the size and shape of the molecule has been investigated. The reduced mobility values increases in the order: alcohols ion mobility spectra of the constitutional isomers studied reflect the influence of structural features. In order to calibrate or determine the detection limits and the sensitivity of the ion mobility spectrometry, the exponential dilution flask (EDF) was used. Using this method, the detection limit of the analytes can reach the order of magnitude of ng x L(-1).

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

    Science.gov (United States)

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

    2016-09-01

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

  6. Emission of Biogenic Volatile Organic Compounds in the Arctic

    DEFF Research Database (Denmark)

    Lindwall, Frida

    Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants...... in the atmosphere. This may warm the climate due to a prolonged lifetime of the potent greenhouse gas methane in the atmosphere. However, oxidized BVOCs may participate in formation or growth of aerosols, which in turn may mitigate climate warming. Climate change in the Arctic, an area characterized by short...... dependent and the emissions will increase in a future warmer climate. The aims of this dissertation were to study BVOC emission rates and blends from arctic ecosystems and to reveal the effect of climate change on BVOC emissions from the Arctic. BVOC emissions were measured in ambient and modified...

  7. Catabolism of volatile organic compounds influences plant survival.

    Science.gov (United States)

    Oikawa, Patricia Y; Lerdau, Manuel T

    2013-12-01

    Plants emit a diverse array of phytogenic volatile organic compounds (VOCs). The production and emission of VOCs has been an important area of research for decades. However, recent research has revealed the importance of VOC catabolism by plants and VOC degradation in the atmosphere for plant growth and survival. Specifically, VOC catabolism and degradation have implications for plant C balance, tolerance to environmental stress, plant signaling, and plant-atmosphere interactions. Here we review recent advances in our understanding of VOC catabolism and degradation, propose experiments for investigating VOC catabolism, and suggest ways to incorporate catabolism into VOC emission models. Improving our knowledge of VOC catabolism and degradation is crucial for understanding plant metabolism and predicting plant survival in polluted environments.

  8. Cyclodextrin-based microsensors for volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, B.; Johnson, S.; Shi, J.; Yang, Xiaoguang

    1997-10-01

    Host-guest chemistry and self-assembly techniques are being explored to develop species selective thin-films for real-time sensing of volatile organic compounds (VOCs). Cyclodextrin (CD) and calixarene (CA) molecules are known to form guest-host inclusion complexes with a variety of organic molecules. Through the control of the cavity size and chemical functionality on the rims of these bucket-like molecules, the binding affinities for formation of inclusion complexes can be controlled and optimized for specific agents. Self-assembly techniques are used to covalently bond these reagent molecules to the surface of acoustic transducers to create dense, highly oriented, and stable thin films. Self-assembly techniques have also been used to fabricate multilayer thin film containing molecular recognition reagents through alternating adsorption of charged species in aqueous solutions. Self-assembly of polymeric molecules of the SAW device was also explored for fabricating species selective interfaces.

  9. HS-SPME-GC-MS ANALYSIS OF VOLATILE AND SEMI-VOLATILE COMPOUNDS FROM DRIED LEAVES OF Mikania glomerata Sprengel

    Directory of Open Access Journals (Sweden)

    Esmeraldo A. Cappelaro

    2015-03-01

    Full Text Available This paper reports on the identification of volatile and semi-volatile compounds and a comparison of the chromatographic profiles obtained by Headspace Solid-Phase Microextraction/Gas Chromatography with Mass Spectrometry detection (HS-SPME-GC-MS of dried leaves of Mikania glomerata Sprengel (Asteraceae, also known as 'guaco.' Three different types of commercial SPME fibers were tested: polydimethylsiloxane (PDMS, polydimethylsiloxane/divinylbenzene (PDMS/DVB and polyacrylate (PA. Fifty-nine compounds were fully identified by HS-SPME-HRGC-MS, including coumarin, a marker for the quality control of guaco-based phytomedicines; most of the other identified compounds were mono- and sesquiterpenes. PA fibers performed better in the analysis of coumarin, while PDMS-DVB proved to be the best choice for a general and non-selective analysis of volatile and semi-volatile guaco-based compounds. The SPME method is faster and requires a smaller sample than conventional hydrodistillation of essential oils, providing a general overview of the volatile and semi-volatile compounds of M. glomerata.

  10. Emissions of biogenic volatile organic compounds & their photochemical transformation

    Science.gov (United States)

    Yu, Zhujun; Hohaus, Thorsten; Tillmann, Ralf; Andres, Stefanie; Kuhn, Uwe; Rohrer, Franz; Wahner, Andreas; Kiendler-Scharr, Astrid

    2015-04-01

    Natural and anthropogenic activities emit volatile organic compounds (VOC) into the atmosphere. While it is known that land vegetation accounts for 90% of the global VOC emissions, only a few molecules' emission factors are understood. Through VOCs atmospheric oxidation intermediate products are formed. The detailed chemical mechanisms involved are insufficiently known to date and need to be understood for air quality management and climate change predictions. In an experiment using a PTR-ToF-MS with the new-built plant chamber SAPHIR-PLUS in Forschungszentrum Juelich, biogenic emissions of volatile organic compounds (BVOC) from Quercus ilex trees were measured. The BVOC emissions were dominated by monoterpenes, minor emissions of isoprene and methanol were also observed with the overall emission pattern typical for Quercus ilex trees in the growing season. Monoterpenes and isoprene emissions showed to be triggered by light. Additionally, their emissions showed clear exponential temperature dependence under constant light condition as reported in literature. As a tracer for leaf growth, methanol emission showed an abrupt increase at the beginning of light exposure. This is explained as instantaneous release of methanol produced during the night once stomata of leaves open upon light exposure. Emission of methanol showed a near linear increase with temperature in the range of 10 to 35 °C. BVOC were transferred from the plant chamber PLUS to the atmospheric simulation chamber SAPHIR, where their oxidation products from O3 oxidation were measured with PTR-ToF-MS. Gas phase oxidation products such as acetone and acetaldehyde were detected. A quantitative analysis of the data will be presented, including comparison of observations to the Master Chemical Mechanism model.

  11. Key volatile compounds in red koji-shochu, a Monascus-fermented product, and their formation steps during fermentation.

    Science.gov (United States)

    Rahayu, Yen Yen Sally; Yoshizaki, Yumiko; Yamaguchi, Keiko; Okutsu, Kayu; Futagami, Taiki; Tamaki, Hisanori; Sameshima, Yoshihiro; Takamine, Kazunori

    2017-06-01

    Red koji, which refers the solid culture grown koji mold on the steamed rice, is one of the ingredients of Asian fermented foods including the Japanese spirit shochu. This study was aimed at elucidating the characteristic flavor and key volatile compounds of red koji-shochu as well as the mechanism of their formation. Sensory evaluation showed that red koji-shochu has the distinctive flavors cheese, sour, milky, and oily. Fifteen key volatile compounds of red koji-shochu were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography, and by comparison between red koji-shochu and white koji-shochu, as another typical shochu. The mash analysis revealed that ketone compounds and short-chain acids derive from red koji. Furthermore, although other key compounds were produced by yeast, it is highly likely that their concentrations were affected directly or indirectly by the high activities of protease and lipase in red koji.

  12. Water-Air Volatilization Factors to Determine Volatile Organic Compound (VOC Reference Levels in Water

    Directory of Open Access Journals (Sweden)

    Vicenç Martí

    2014-06-01

    Full Text Available The goal of this work is the modeling and calculation of volatilization factors (VFs from water to air for volatile organic compounds (VOCs in order to perform human health risk-based reference levels (RLs for the safe use of water. The VF models have been developed starting from the overall mass-transfer coefficients (Koverall concept from air to water for two interaction geometries (flat surface and spherical droplets in indoor and outdoor scenarios. For a case study with five groups of risk scenarios and thirty VOCs, theoretical VFs have been calculated by using the developed models. Results showed that Koverall values for flat and spherical surface geometries were close to the mass transfer coefficient for water (KL when Henry’s law constant (KH was high. In the case of spherical drop geometry, the fraction of volatilization (fV was asymptotical when increasing KH with fV values also limited due to Koverall. VFs for flat surfaces were calculated from the emission flux of VOCs, and results showed values close to 1000KH for the most conservative indoor scenarios and almost constant values for outdoor scenarios. VFs for spherical geometry in indoor scenarios followed also constant VFs and were far from 1000KH. The highest calculated VF values corresponded to the E2A, E2B, E3A and E5A scenarios and were compared with experimental and real results in order to check the goodness of flat and sphere geometry models. Results showed an overestimation of calculated values for the E2A and E2B scenarios and an underestimation for the E3A and E5A scenarios. In both cases, most of the calculated VFs were from 0.1- to 10-times higher than experimental/real values.

  13. Vapor condensation onto a non-volatile liquid drop

    Energy Technology Data Exchange (ETDEWEB)

    Inci, Levent; Bowles, Richard K., E-mail: richard.bowles@usask.ca [Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9 (Canada)

    2013-12-07

    Molecular dynamics simulations of miscible and partially miscible binary Lennard–Jones mixtures are used to study the dynamics and thermodynamics of vapor condensation onto a non-volatile liquid drop in the canonical ensemble. When the system volume is large, the driving force for condensation is low and only a submonolayer of the solvent is adsorbed onto the liquid drop. A small degree of mixing of the solvent phase into the core of the particles occurs for the miscible system. At smaller volumes, complete film formation is observed and the dynamics of film growth are dominated by cluster-cluster coalescence. Mixing into the core of the droplet is also observed for partially miscible systems below an onset volume suggesting the presence of a solubility transition. We also develop a non-volatile liquid drop model, based on the capillarity approximations, that exhibits a solubility transition between small and large drops for partially miscible mixtures and has a hysteresis loop similar to the one observed in the deliquescence of small soluble salt particles. The properties of the model are compared to our simulation results and the model is used to study the formulation of classical nucleation theory for systems with low free energy barriers.

  14. Biodegradation of volatile organic compounds by five fungal species

    Energy Technology Data Exchange (ETDEWEB)

    Qi, B.; Moe, W.M. [Dept. of Civil and Environmental Engineering, Louisiana State Univ., Baton Rouge, LA (United States); Kinney, K.A. [Dept. of Civil Engineering, Univ. of Texas, Austin (United States)

    2002-07-01

    Five fungal species, Cladosporium resinae (ATCC 34066), Cladosporium sphaerospermum (ATCC 200384), Exophiala lecanii-corni (CBS 102400), Mucor rouxii (ATCC 44260), and Phanerochaete chrysosporium (ATCC 24725), were tested for their ability to degrade nine compounds commonly found in industrial off-gas emissions. Fungal cultures inoculated on ceramic support media were provided with volatile organic compounds (VOCs) via the vapor phase as their sole carbon and energy sources. Compounds tested included aromatic hydrocarbons (benzene, ethylbenzene, toluene, and styrene), ketones (methyl ethyl ketone, methyl isobutyl ketone, and methyl propyl ketone), and organic acids (n-butyl acetate, ethyl 3-ethoxypropionate). Experiments were conducted using three pH values ranging from 3.5 to 6.5. Fungal ability to degrade each VOC was determined by observing the presence or absence of visible growth on the ceramic support medium during a 30-day test period. Results indicate that E. lecanii-corni and C. sphaerospermum can readily utilize each of the nine VOCs as a sole carbon and energy source. P. chrysosporium was able to degrade all VOCs tested except for styrene under the conditions imposed. C. resinae was able to degrade both organic acids, all of the ketones, and some of the aromatic compounds (ethylbenzene and toluene); however, it was not able to grow utilizing benzene or styrene under the conditions tested. With the VOCs tested, M. rouxii produced visible growth only when supplied with n-butyl acetate or ethyl 3-ethoxypropionate. Maximum growth for most fungi was observed at a pH of approximately 5.0. The experimental protocol utilized in these studies is a useful tool for assessing the ability of different fungal species to degrade gas-phase VOCs under conditions expected in a biofilter application. (orig.)

  15. Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Rodolfo Sosa, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Humberto Bravo, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico)], E-mail: hbravo@servidor.unam.mx; Violeta Mugica, A. [Universidad Autonoma Metropolitana, Azcapotzalco, D.F. (Mexico); Pablo Sanchez, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Emma Bueno, L. [Centro Nacional de Investigacion y Capacitacion Ambiental, Instituto Nacional de Ecologia (Mexico); Krupa, Sagar [Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (United States)

    2009-03-15

    Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City.

  16. [Study of volatile organic compounds of fresh allium species using headspace combined with surface-enhanced Raman scattering].

    Science.gov (United States)

    Si, Min-Zhen; Zhang, De-Qing; Liu, Ren-Ming

    2014-09-01

    In order to identify volatile organic compounds of fresh plants at room temperature and avoid sample pretreatment and extractions which can be labor intensive, garlic, Chinese chives and scallion were chopped into pieces. Then some of them were placed in the headspace vial and sealed. The gases were drawn from the vial with a syringe and were injected very slowly into Ag colloids for test using R-3000 portable Raman spectrometer. The spectra of volatile organic compounds of allium species, fresh garlic, Chinese chive and shallot plants were successfully.recorded for the first time. For garlic high intensity bands are present at 307, 399, 569, 711, 1,182, 1,287, 1,397 and 1,622 cm(-1). For Chinese chives the high intensity band is present at 672 cm(-1). Low intensity bands are present at 274, 412, 575, 1,185, 1,289, 1,396, 1,618 cm(-1). For shallot high intensity bands are present at 693 cm(-1). Lower intensity bands are present at 372, 888, 1,023 cm(-1). Low intensity bands are present at 1,088, 1,211 and 1,322 cm(-1). The SERS of diallyl disulfide, allyl methyl sulfide and 1-propanethiol in liquid state and gas state were also obtained. The main volatile organic compound of fresh garlic, Chinese chive and shallot are diallyl disulfide, allyl methyl sulfide and 1-propanethiol respectively, and the volatile organic compound of fresh onion, scallion, shallot and chive are all 1-propanethiol. The presented results illustrate that combining headspace and SERS is a powerful tool for volatile organic compound analysis in fresh plants. The volatile organic compound can be detected in fresh plant samples directly and quickly without extraction.

  17. 78 FR 55234 - Approval and Promulgation of Implementation Plans; Indiana; Volatile Organic Compound Emission...

    Science.gov (United States)

    2013-09-10

    ... Compound Emission Control Measures for Industrial Solvent Cleaning for Northwest Indiana AGENCY... of Environmental Management (IDEM) submitted revisions to its volatile organic compound (VOC... less than or equal to 8 millimeters of mercury; (2) several work practices must be...

  18. Diurnal characteristics of volatile organic compounds in the Seoul atmosphere

    Science.gov (United States)

    Na, Kwangsam; Kim, Yong Pyo; Moon, Kil Choo

    Concentrations of volatile organic compounds (VOCs) were measured at a site in central Seoul from 8 to 13 September 1998. On each sampling day, three 2-h-integrated canister samples were collected in the morning, afternoon and evening, respectively, to observe diural variations of VOCs. Most of the VOCs species showed diurnal variations with higher concentrations during the morning and evening, and lower concentrations during the afternoon. However, in the afternoon, the concentrations of aromatic compounds, closely correlated with solvent usage such as toluene, ethylbenzene, m-/p-xylene, and o-xylene, were slightly higher than or comparable to those in the morning. This may be due to the increase of evaporative emissions derived from the rise in ambient temperature and additional sources such as the use of solvents in painting, printing and dry cleaning. To estimate the participation of individual VOCs in ozone formation, propylene equivalent concentrations were calculated. The results showed that toluene was the most dominant contributor to ozone formation as well as ambient VOC concentrations. Toluene/benzene and m-/ p-xylene/benzene ratios showed a high observed in the afternoon and a low observed in the morning and evening. This may be because the contribution of evaporative emissions by solvent usage on the ambient VOC concentrations is more dominant than those of vehicle-related emissions and photochemical loss.

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

    Science.gov (United States)

    Chein, HungMin; Chen, Tzu Ming

    2003-08-01

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

  20. Constituents of volatile organic compounds of evaporating essential oil

    Science.gov (United States)

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

    2009-12-01

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

  1. Volatile organic compounds in fourteen U.S. retail stores.

    Science.gov (United States)

    Nirlo, E L; Crain, N; Corsi, R L; Siegel, J A

    2014-10-01

    Retail buildings have a potential for both short-term (customer) and long-term (occupational) exposure to indoor pollutants. However, little is known about volatile organic compound (VOC) concentrations in the retail sector and influencing factors, such as ventilation, in-store activities, and store type. We measured VOC concentrations and ventilation rates in 14 retail stores in Texas and Pennsylvania. With the exception of formaldehyde and acetaldehyde, VOCs were present in retail stores at concentrations well below health guidelines. Indoor formaldehyde concentrations ranged from 4.6 ppb to 67 ppb. The two mid-sized grocery stores in the sample had the highest levels of ethanol and acetaldehyde, with concentrations up to 2.6 ppm and 92 ppb, respectively, possibly due to the preparation of dough and baking activities. Indoor-to-outdoor concentration ratios indicated that indoor sources were the main contributors to indoor VOC concentrations for the majority of compounds. There was no strong correlation between ventilation and VOC concentrations across all stores. However, increasing the air exchange rates at two stores led to lower indoor VOC concentrations, suggesting that ventilation can be used to reduce concentrations for some specific stores.

  2. Gas chromatography-olfactometry analysis of the volatile compounds of two commercial Irish beef meats

    NARCIS (Netherlands)

    Machiels, D.; Ruth, van S.M.; Posthumus, M.A.; Istasse, L.

    2003-01-01

    The volatile flavour compounds of two commercial Irish beef meats (labelled as conventional and organic) were evaluated by gas chromatography-olfactometry and were identified by gas chromatography-mass spectrometry. The volatile compounds were isolated in a model mouth system. Gas

  3. 40 CFR 60.542a - Alternate standard for volatile organic compounds.

    Science.gov (United States)

    2010-07-01

    ... Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a) On... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  4. 40 CFR 60.312 - Standard for volatile organic compounds (VOC).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Surface Coating of Metal Furniture § 60.312 Standard for volatile organic compounds (VOC). (a) On...

  5. 40 CFR 60.112 - Standard for volatile organic compounds (VOC).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... After June 11, 1973, and Prior to May 19, 1978 § 60.112 Standard for volatile organic compounds...

  6. 75 FR 57412 - Approval and Promulgation of Implementation Plans Alabama: Volatile Organic Compounds

    Science.gov (United States)

    2010-09-21

    ... ``volatile organic compounds'' (VOCs) found at Alabama Administrative Code section 335-3-1-.02(gggg... AGENCY 40 CFR Part 52 Approval and Promulgation of Implementation Plans Alabama: Volatile Organic Compounds AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing...

  7. 75 FR 82363 - Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound Emission...

    Science.gov (United States)

    2010-12-30

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound... printing volatile organic compound (VOC) rule for approval into the Ohio State Implementation Plan (SIP... mercury at 20 degrees Celsius. This rule also contains the appropriate test methods ] for determining...

  8. Characterization of volatile compounds in Fen-Daqu - a traditional Chinese liquor fermentation starter

    NARCIS (Netherlands)

    Van-Diep, L.; Zheng, X.; Chen, J.Y.; Han, B.Z.

    2012-01-01

    Fen-Daqu is a saccharifying agent and fermentation starter for the production of Chinese liquor Fen (alcoholic spirit) and Fen traditional vinegar. The volatile compounds produced at seven incubation steps were analysed by HS-SPME-GC-MS. A total of 83 major volatile compounds were identified,

  9. Gas chromatography-olfactometry analysis of the volatile compounds of two commercial Irish beef meats

    NARCIS (Netherlands)

    Machiels, D.; Ruth, van S.M.; Posthumus, M.A.; Istasse, L.

    2003-01-01

    The volatile flavour compounds of two commercial Irish beef meats (labelled as conventional and organic) were evaluated by gas chromatography-olfactometry and were identified by gas chromatography-mass spectrometry. The volatile compounds were isolated in a model mouth system. Gas chromatography-olf

  10. Characterization of volatile compounds in Fen-Daqu - a traditional Chinese liquor fermentation starter

    NARCIS (Netherlands)

    Van-Diep, L.; Zheng, X.; Chen, J.Y.; Han, B.Z.

    2012-01-01

    Fen-Daqu is a saccharifying agent and fermentation starter for the production of Chinese liquor Fen (alcoholic spirit) and Fen traditional vinegar. The volatile compounds produced at seven incubation steps were analysed by HS-SPME-GC-MS. A total of 83 major volatile compounds were identified, includ

  11. Volatile sulphur compounds elimination: A new insight in periodontal treatment

    Directory of Open Access Journals (Sweden)

    Ernie Maduratna Setiawatie

    2011-12-01

    Full Text Available Background: Recent evidences had demonstrated a link between halitosis and apoptosis in periodontitis. Periodontal pathogenic micro-organisms produce volatile sulphur compounds (VSCs. VSCs are toxic to periodontal tissue. Purpose: The purpose of this paper was to reveal the mechanism of VSCs in periodontal breakdown according to the most recent knowledges. Reviews: Halitosis is mainly attributed to VSCs such as hydrogen sulfide, methyl mercaptan and dimethyl sulfide. Several studies demonstrated a strong relationship between VSCs and periodontal disease progression. VSCs are released from amino acid breakdown from food, protein, cells, blood and saliva. In prone subjects, the VSCs may cause alteration in tissue integrity by increasing its permeability and facilitate the endotoxin to penetrate the tissue barrier. They may also causing apoptotic in gingival and periodontal tissue, which are considered the main pathogenesis in aggravating the periodontitis. VSCs may also initiate the increase of proinflammatory cytokines which is considered to have negative effects in host response. Conclusion: VSCs had been shown to have detrimental effects in gingival and periodontal ligament cells. The use of chlorine dioxine agent and topical antioxidant is beneficial in controlling the periodontal disease severity.Latar belakang: Penelitian terakhir menunjukkan adanya hubungan antara halitosis dengan terjadinya apoptosis pada periodontitis. Mikroorganisme penyebab periodontitis memproduksi volatile sulphur compounds (VSCs yang bersifat toksik terhadap jaringan periodontal. Tujuan: Tujuan penulisan ini adalah membahas mekanisme VSCs dalam menyebabkan kerusakan periodontal berdasarkan penelitian terakhir yang ada. Tinjauan pustaka: Halitosis seringkali dikaitkan dengan timbulnya VSCs seperti hidrogen sulfida, metil merkaptan, dan dimetil sulfida. Penelitian terakhir menunjukkan bahwa VSCs yang dilepaskan dari pemecahan asam amino makanan ternyata memiliki

  12. Solid phase microextraction for profiling volatile compounds in liquered white wines

    Directory of Open Access Journals (Sweden)

    Henryk H. Jeleń

    2010-03-01

    Full Text Available Background. Profile of volatile compounds is a distinct feature of wine, which is dependent on the type of wine, grapes, fermentation and ageing processes. Profiling volatile compounds in wine using fast method provides information on major groups of compounds and can be used for classification/differentiation purposes. Solid phase microextraction (SPME was used for the profiling of volatile compounds in liquered white wines in this study. Material and methods. Different fibers were tested for this purpose: PDMS, Carboxene/ PDMS, Carboxene/DVB/PDMS, Polyacrylate, Divinylbenzene/PDMS. Different times were compared to optimize extraction process. Profile and amount of volatile compounds extracted by SPME fiber was compared for eight liquered white wines. Results. Carboxene/DVB/PDMS showed the highest efficiency in extracting higher alcohols, esters, carbonyls and terpenes. Of tested extraction times ranging from 5 to 30 min. 20 minutes was chosen providing sufficient peak responses. Using SPME total amount of volatile compounds in eight liquered wines was compared – Riversaltes, Offley Porto and Jutrzenka having the highest amount of adsorbed volatiles. Profiles of volatiles of analysed wines revealed that dominating compounds in 6 wines were esters, followed by higher alcohols, two analysed Muscat wines had high terpene contents compared to remaining wines. Conclusion. SPME can be used for relatively fast profiling of wine volatiles, that can be used for wines classification.  

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

    Science.gov (United States)

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

    2011-06-22

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

  14. Measurements of Volatile Organic Compounds in a Newly Built Daycare Center.

    Science.gov (United States)

    Noguchi, Miyuki; Mizukoshi, Atsushi; Yanagisawa, Yukio; Yamasaki, Akihiro

    2016-07-21

    We measured temporal changes in concentrations of total volatile organic compounds (TVOCs) and individual volatile organic compounds in a newly built daycare center. The temporal changes of the TVOC concentrations were monitored with a photo ionization detector (PID), and indoor air was sampled and analyzed by Gas Chromatography/Mass Spectrometry (GC/MS) and high performance liquid chromatography (HPLC) to determine the concentrations of the constituent VOCs. The measurements were performed just after completion of the building and again 3 months after completion. The TVOC concentration exceeded 1000 µg·m(-3) for all the sampling locations just after completion of building, and decreased almost one tenth after 3 months, to below the guideline values of the TVOC in Japan at 400 µg·m(-3). The concentrations of the target VOCs of which the indoor concentrations are regulated in Japan were below the guideline values for all the cases. The air-exchange rates were determined based on the temporal changes of the TVOC concentrations, and it was found that the countermeasure to increase the air exchange rate successfully decrease the TVOC concentration level in the rooms.

  15. Measurements of Volatile Organic Compounds in a Newly Built Daycare Center

    Directory of Open Access Journals (Sweden)

    Miyuki Noguchi

    2016-07-01

    Full Text Available We measured temporal changes in concentrations of total volatile organic compounds (TVOCs and individual volatile organic compounds in a newly built daycare center. The temporal changes of the TVOC concentrations were monitored with a photo ionization detector (PID, and indoor air was sampled and analyzed by Gas Chromatography/Mass Spectrometry (GC/MS and high performance liquid chromatography (HPLC to determine the concentrations of the constituent VOCs. The measurements were performed just after completion of the building and again 3 months after completion. The TVOC concentration exceeded 1000 µg·m−3 for all the sampling locations just after completion of building, and decreased almost one tenth after 3 months, to below the guideline values of the TVOC in Japan at 400 µg·m−3. The concentrations of the target VOCs of which the indoor concentrations are regulated in Japan were below the guideline values for all the cases. The air-exchange rates were determined based on the temporal changes of the TVOC concentrations, and it was found that the countermeasure to increase the air exchange rate successfully decrease the TVOC concentration level in the rooms.

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

    Directory of Open Access Journals (Sweden)

    Tanzeela Khalid

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

  17. Characterization of volatile organic compounds from different cooking emissions

    Science.gov (United States)

    Cheng, Shuiyuan; Wang, Gang; Lang, Jianlei; Wen, Wei; Wang, Xiaoqi; Yao, Sen

    2016-11-01

    Cooking fume is regarded as one of the main sources of urban atmospheric volatile organic compounds (VOCs) and its chemical characteristics would be different among various cooking styles. In this study, VOCs emitted from four different Chinese cooking styles were collected. VOCs concentrations and emission characteristics were analyzed. The results demonstrated that Barbecue gave the highest VOCs concentrations (3494 ± 1042 μg/m3), followed by Hunan cuisine (494.3 ± 288.8 μg/m3), Home cooking (487.2 ± 139.5 μg/m3), and Shandong cuisine (257.5 ± 98.0 μg/m3). The volume of air drawn through the collection hood over the stove would have a large impact on VOCs concentration in the exhaust. Therefore, VOCs emission rates (ER) and emission factors (EF) were also estimated. Home cooking had the highest ER levels (12.2 kg/a) and Barbecue had the highest EF levels (0.041 g/kg). The abundance of alkanes was higher in Home cooking, Shandong cuisine and Hunan cuisine with the value of 59.4%-63.8%, while Barbecue was mainly composed of alkanes (34.7%) and alkenes (39.9%). The sensitivity species of Home cooking and Hunan cuisine were alkanes, and that of Shandong cuisine and Barbecue were alkenes. The degree of stench pollution from cooking fume was lighter.

  18. Volatile organic silicon compounds: the most undesirable contaminants in biogases.

    Science.gov (United States)

    Ohannessian, Aurélie; Desjardin, Valérie; Chatain, Vincent; Germain, Patrick

    2008-01-01

    Recently a lot of attention has been focused on volatile organic silicon compounds (VOSiC) present in biogases. They induce costly problems due to silicate formation during biogas combustion in valorisation engine. The cost of converting landfill gas and digester gas into electricity is adversely affected by this undesirable presence. VOSiC in biogases spark off formation of silicate deposits in combustion chambers. They engender abrasion of the inner surfaces leading to serious damage, which causes frequent service interruptions, thus reducing the economic benefit of biogases. It is already known that these VOSiC originate from polydimethylsiloxanes (PDMS) hydrolysis. PDMS (silicones) are used in a wide range of consumer and industrial applications. PDMS are released into the environment through landfills and wastewater treatment plants. There is a lack of knowledge concerning PDMS biodegradation during waste storage. Consequently, understanding PDMS behaviour in landfill cells and in sludge digester is particularly important. In this article, we focused on microbial degradation of PDMS through laboratory experiments. Preliminary test concerning anaerobic biodegradation of various PDMS have been investigated. Results demonstrate that the biotic step has an obvious influence on PDMS biodegradation. IWA Publishing 2008.

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

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-hui; BAI Yu-hua; ZHANG Shu-yu

    2005-01-01

    The first detailed inventory for volatile organic compounds(VOC) emissions from vegetation over Yunnan Province, China was presented. The spatially and temporally resolved inventory was developed based on a geographic information system (GIS), remote sensing(RS) data and field measurement data, such as digitized land-use data, normalized difference vegetation index (NDVl) and temperature data from direct real-time measurement. The inventory has a spatial resolution of 5 km × 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 × 1012 gC for total annual biogenic VOC emissions from Yunnan Province, including 6.1 × 1011 gCfor isoprene, 2.1 × 1011 gC for monoterpenes, and 2.6 × 1011 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.

  20. Analysis of volatile organic compounds released during food decaying processes.

    Science.gov (United States)

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

    2012-03-01

    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.

  1. Development and mining of a volatile organic compound database.

    Science.gov (United States)

    Abdullah, Azian Azamimi; Altaf-Ul-Amin, Md; Ono, Naoaki; Sato, Tetsuo; Sugiura, Tadao; Morita, Aki Hirai; Katsuragi, Tetsuo; Muto, Ai; Nishioka, Takaaki; Kanaya, Shigehiko

    2015-01-01

    Volatile organic compounds (VOCs) are small molecules that exhibit high vapor pressure under ambient conditions and have low boiling points. Although VOCs contribute only a small proportion of the total metabolites produced by living organisms, they play an important role in chemical ecology specifically in the biological interactions between organisms and ecosystems. VOCs are also important in the health care field as they are presently used as a biomarker to detect various human diseases. Information on VOCs is scattered in the literature until now; however, there is still no available database describing VOCs and their biological activities. To attain this purpose, we have developed KNApSAcK Metabolite Ecology Database, which contains the information on the relationships between VOCs and their emitting organisms. The KNApSAcK Metabolite Ecology is also linked with the KNApSAcK Core and KNApSAcK Metabolite Activity Database to provide further information on the metabolites and their biological activities. The VOC database can be accessed online.

  2. Microcantilever sensors coated with a sensitive polyaniline layer for detecting volatile organic compounds.

    Science.gov (United States)

    Steffens, C; Leite, F L; Manzoli, A; Sandovall, R D; Fatibello, O; Herrmann, P S P

    2014-09-01

    This paper describes a silicon cantilever sensor coated with a conducting polymer layer. The mechanical response (deflection) of the bimaterial (the coated microcantilever) was investigated under the influence of several volatile compounds-methanol, ethanol, acetone, propanol, dichloroethane, toluene and benzene. The variations in the deflection of the coated and uncoated microcantilevers when exposed to volatile organic compounds were evaluated, and the results indicated that the highest sensitivity was obtained with the coated microcantilever and methanol. The uncoated microcantilever was not sensitive to the volatile organic compounds. An increase in the concentration of the volatile organic compound resulted in higher deflections of the microcantilever sensor. The sensor responses were reversible, sensible, rapid and proportional to the volatile concentration.

  3. Non-conventional gas phase remediation of volatile halogenated compounds by dehydrated bacteria

    OpenAIRE

    Erable, Benjamin; Goubet, Isabelle; Seltana, Amira; Maugard, Thierry

    2009-01-01

    Traditional biological removal processes are limited by the low solubility of halogenated compounds in aqueous media. A new technology appears very suitable for the remediation of these volatile organic compounds (VOCs). Solid/gas bio-catalysis applied in VOC remediation can transform halogenated compounds directly in the gas phase using dehydrated cells as a bio-catalyst. The hydrolysis of volatile halogenated substrates into the corresponding alcohol was studied in a solid/gas bio...

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

    Science.gov (United States)

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

    2013-04-01

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

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

    Science.gov (United States)

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

    2015-03-01

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

  6. Correct quantitative determination of ethanol and volatile compounds in alcohol products

    CERN Document Server

    Charapitsa, Siarhei; Sytova, Svetlana; Yakuba, Yurii

    2014-01-01

    Determination of the volume content of ethanol in the alcohol products in practice is usually determined by pycnometry, electronic densimetry, or densimetry using a hydrostatic balance in accordance with Commission Regulation No 2870/2000. However, these methods determine directly only density of the tested liquid sample and does not take into account the effects of other volatile components such as aldehydes, esters and higher alcohols. So they are appropriate only for binary water-ethanol solutions in accordance with international table adopted by the International Legal Metrology Organization in its Recommendation No 22. Availability notable concentrations of the higher alcohols and ethers in different alcohol-based products, e. g. in whisky, cognac, brandy, wine as well as in waste alcohol and alcohol beverage production, leads to the significant contribution of these compounds in the value of the density of tested alcohol-containing sample. As a result, determination of the volume of ethanol content for ...

  7. Volatile Compounds and Capsaicinoid Content of Fresh Hot Peppers (Capsicum Chinense Scotch Bonnet Variety at Red Stage

    Directory of Open Access Journals (Sweden)

    Arthur Gahungu

    2011-06-01

    Full Text Available The aim of this study was to evaluate the capsaicinoids content and the volatile compounds of fresh hot pepper from Burundi at red stage. The Capsaicinoids were extracted in acetone and separated using column chromatography on silica gel, then evaluated quantitatively using a reverse phase High performance liquid chromatography/Photodiode array detection (RP-HPLC/PAD. The volatile compounds were extracted by hydrodistillation and then re-extracted and concentrated by SPME fiber at 55ºC for 30 min and analyzed using Gas chromatography-mass spectrometry (GC-MS. Seventy volatile compounds were identified, of which aliphatic esters, alcohols, terpenoids and acids were the main classes. Hexyl pentanoate, hexyl isopentanoate, Pentyl 3- methylbutanoate, 10- undecenol, 3, 3- dimethyl cyclohexanol, β-chamigrene, Pentadecanoic acid, (E- 9- tetradecenoic acid and Hexadecanoic acid were found to be the major volatile constituents. Capsaicin (CAPS 47.632 mg/g and dihydrocapsaicin (DHCAPS 23.096 mg/g were the major capsaicinoids and their contents converted in Scoville heat value (142931 show that the Scotch Bonnet variety is a high hot chili pepper according to the Scoville scale.

  8. Ethanol as Internal Standard for Quantitative Determination of Volatile Compounds in Spirit Drinks by Gas Chromatography

    CERN Document Server

    Charapitsa, Siarhei V; Kulevich, Nikita V; Makoed, Nicolai M; Mazanik, Arkadzi L; Sytova, Svetlana N

    2012-01-01

    The new methodical approach of using ethanol as internal standard in gas chromatographic analysis of volatile compounds in spirit drinks in daily practice of testing laboratories is proposed. This method provides determination of volatile compounds concentrations in spirit drinks directly expressed in milligrams per liter (mg/L) of absolute alcohol according to official methods without measuring of alcohol strength of analyzed sample. The experimental demonstration of this method for determination of volatile compounds in spirit drinks by gas chromatography is described. Its validation was carried out by comparison with experimental results obtained by internal standard method and external standard method.

  9. Transport of volatile organic compounds across the capillary fringe

    Science.gov (United States)

    McCarthy, Kathleen A.; Johnson, Richard L.

    1993-01-01

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

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

    Science.gov (United States)

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

    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 source of reactive trace com- pounds, which are transported directly into the planetary boundary layer (PBL). In particular, little is known about the amounts of VOC which are processed within the canopy. The goal of ECHO, which is presented in this poster, is to investigate these questions and to improve our understanding of biosphere-atmosphere interactions and their effects on the PBL. The investigation of emissions, chemical processing and vertical transport of biogenic VOC will be carried out in and above a mixed forest stand in Jülich, Germany. A large set of trace gases, free radicals and meteorologi- cal parameters will be measured at different heights in and above the canopy, covering concentrations of VOC, CO, O3, organic nitrates und NOx as well as organic aerosols. For the first time concentration profiles of OH, HO2, RO2 und NO3 radicals will be measured as well together with the actinic UV radiation field and photolysis frequen- cies of all relevant radical precursors (O3, NO2, peroxides, oxygenated VOC). The different tasks of the field experiments will be supported by simulation experiments investigating the primary emission and the uptake of VOC by the plants in stirred tank reactors, soil parameters and soil emissions in lysimeter experiments, and the chem- ical processing of the trace gases as observed in and above the forest stand in the atmosphere simulation chamber SAPHIR. The planning and interpretation of the field experiments is supported by simulations of the field site in a wind tunnel.

  11. Diagnosing Tibetan pollutant sources via volatile organic compound observations

    Science.gov (United States)

    Li, Hongyan; He, Qiusheng; Song, Qi; Chen, Laiguo; Song, Yongjia; Wang, Yuhang; Lin, Kui; Xu, Zhencheng; Shao, Min

    2017-10-01

    Atmospheric transport of black carbon (BC) from surrounding areas has been shown to impact the Tibetan environment, and clarifying the geographical source and receptor regions is crucial for providing guidance for mitigation actions. In this study, 10 trace volatile organic compounds (VOCs) sampled across Tibet are chosen as proxies to diagnose source regions and related transport of pollutants to Tibet. The levels of these VOCs in Tibet are higher than those in the Arctic and Antarctic regions but much lower than those observed at many remote and background sites in Asia. The highest VOC level is observed in the eastern region, followed by the southern region and the northern region. A positive matrix factorization (PMF) model found that three factors-industry, biomass burning, and traffic-present different spatial distributions, which indicates that different zones of Tibet are influenced by different VOC sources. The average age of the air masses in the northern and eastern regions is estimated to be 3.5 and 2.8 days using the ratio of toluene to benzene, respectively, which indicates the foreign transport of VOC species to those regions. Back-trajectory analyses show that the Afghanistan-Pakistan-Tajikistan region, Indo-Gangetic Plain (IGP), and Meghalaya-Myanmar region could transport industrial VOCs to different zones of Tibet from west to east. The agricultural bases in northern India could transport biomass burning-related VOCs to the middle-northern and eastern zones of Tibet. High traffic along the unique national roads in Tibet is associated with emissions from local sources and neighboring areas. Our study proposes international joint-control efforts and targeted actions to mitigate the climatic changes and effects associated with VOCs in Tibet, which is a climate sensitive region and an important source of global water.

  12. Assessment of volatile organic compound emissions from ecosystems of China

    Science.gov (United States)

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

    2002-11-01

    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 regions of China: Inner Mongolia (temperate), Changbai Mountain (boreal-temperate), Beijing Mountain (temperate), Dinghu Mountain (subtropical), Ailao Mountain (subtropical), Kunming (subtropical), and Xishuangbanna (tropical). Transects were used to sample plant species and growth form composition, leafy (green) biomass, and leaf area in forests representing nearly all the major forest types of China. Leafy biomass was determined using generic algorithms based on tree diameter, canopy structure, and absolute cover. Measurements of VOC emissions were made on 386 of the 541 recorded species using a portable photo-ionization detector method. For 105 species, VOC emissions were also measured using a flow-through leaf cuvette sampling/gas chromatography analysis method. Results indicate that isoprene and monoterpene emissions, as well as leafy biomass, vary systematically along gradients of ecological succession in the same manner found in previous studies in the United States, Canada, and Africa. Applying these results to a regional VOC emissions model, we arrive at a value of 21 Tg C for total annual biogenic VOC emissions from China, compared to 5 Tg C of VOCs released annually from anthropogenic sources there. The isoprene and monoterpene emissions are nearly the same as those reported for Europe, which is comparable in size to China.

  13. Stable carbon isotope ratios of ambient aromatic volatile organic compounds

    Science.gov (United States)

    Kornilova, Anna; Huang, Lin; Saccon, Marina; Rudolph, Jochen

    2016-09-01

    Measurements of mixing ratios and stable carbon isotope ratios of aromatic volatile organic compounds (VOC) in the atmosphere were made in Toronto (Canada) in 2009 and 2010. Consistent with the kinetic isotope effect for reactions of aromatic VOC with the OH radical the observed stable carbon isotope ratios are on average significantly heavier than the isotope ratios of their emissions. The change of carbon isotope ratio between emission and observation is used to determine the extent of photochemical processing (photochemical age, ∫ [OH]dt) of the different VOC. It is found that ∫ [OH]dt of different VOC depends strongly on the VOC reactivity. This demonstrates that for this set of observations the assumption of a uniform ∫ [OH]dt for VOC with different reactivity is not justified and that the observed values for ∫ [OH]dt are the result of mixing of VOC from air masses with different values for ∫ [OH]dt. Based on comparison between carbon isotope ratios and VOC concentration ratios it is also found that the varying influence of sources with different VOC emission ratios has a larger impact on VOC concentration ratios than photochemical processing. It is concluded that for this data set the use of VOC concentration ratios to determine ∫ [OH]dt would result in values for ∫ [OH]dt inconsistent with carbon isotope ratios and that the concept of a uniform ∫ [OH]dt for an air mass has to be replaced by the concept of individual values of an average ∫ [OH]dt for VOC with different reactivity.

  14. Pengaruh Ritma Circadian Terhadap Produksi Volatile Sulfur Compounds (VSC Oral

    Directory of Open Access Journals (Sweden)

    Supriatno Supriatno

    2013-06-01

    Full Text Available Volatile sulfur compounds (VSCs oral dihasilkan dari produk putrifikasi mikroba gas hidrogen sulfida (H2S, metil merkaptan (CH3SH dan dimetil sulfida [(CH32S] yang merupakan gas utama penyebab halitosis. Ritma circadian mempunyai pengaruh terhadap fungsi beberapa organ tubuh termasuk sekresi saliva, produksi hormon, fungsi sistem tubuh, dan aktivitas mikroorganisma. Penelitian bertujuan menguji pengaruh ritma circadian terhadap produksi VSC oral yang diukur menggunakan OralChroma portable. Penelitian dilakukan dengan mengukur gas VSC individu yang sama pada pagi, siang dan malam hari di laboratorium riset terpadu FKG UGM. Hasil pengukuran H2S, CH3SH dan (CH32S diuji menggunakan analisis statistik Anava dua jalur dilanjutkan uji LSD dan uji korelasi Pearson dengan derajat kemaknaan 95%. Hasil penelitian menunjukkan terdapat perbedaan yang sangat bermakna antara produksi gas H2S, CH3SH dan (CH32S dengan waktu pengukuran (efek circadian (p=0,000. Perbedaan sangat bermakna diketahui pula pada pengukuran gas H2S dan (CH32S antara pagi, siang dan malam (p=0,01 dan p= 0,00, serta pengukuran gas CH3SH siang dan malam (p=0,006, tetapi tidak pada CH3SH pagi hari (p=0,061. Produksi gas H2S tertinggi diketahui pada pagi hari (mean 1,198 ng/10 ml, CH3SH pada malam hari (mean 0,099 ng/10 ml, dan (CH32S pada siang hari (mean 1,216 ng/10 ml. Kekuatan hubungan pengukuran antara ke tiga gas dengan efek circadian diketahui sebesar r=0,738. Disimpulkan bahwa ritma circadian berpengaruh terhadap produksi VSCs oral. Produksi gas H2S dan (CH32S berbeda antara pagi, siang dan malam hari, sedangkan produksi gas CH3SH berbeda hanya pengukuran siang dan malam hari. Produksi gas H2S tertinggi diketahui pada pagi hari, gas CH3SH pada malam hari, dan gas (CH32S pada siang hari. Maj Ked Gi. Juni 2013; 20(1: 14 - 20. The Effect Of Circadian Rhythm To Oral Volatile Sulfur Compounds Production. Oral volatile sulfur compound (VSC is produced from microbial purification

  15. Comparison of two common adsorption materials for thermal desorption gas chromatography - mass spectrometry of biogenic volatile organic compounds.

    Science.gov (United States)

    Marcillo, Andrea; Jakimovska, Viktorija; Widdig, Anja; Birkemeyer, Claudia

    2017-09-08

    Volatile organic compounds (VOCs) are commonly collected from gaseous samples by adsorption to materials such as the porous polymer Tenax TA. Adsorbed compounds are subsequently released from these materials by thermal desorption (TD) and separated then by gas chromatography (GC) with flame ionization (FID) or mass spectrometry (MS) detection. Tenax TA is known to be particularly suitable for non-polar to semipolar volatiles, however, many volatiles from environmental and biological samples possess a rather polar character. Therefore, we tested if the polymer XAD-2, which so far is widely used to adsorb organic compounds from aqueous and organic solvents, could provide a broader coverage for (semi)polar VOCs during gas-phase sampling. Mixtures of volatile compounds covering a wide range of volatility (bp. 20-256°C) and different chemical classes were introduced by liquid spiking into sorbent tubes with one of the two porous polymers, Tenax TA or XAD-2, and analyzed by TD/GC-MS. At first, an internal standard mixture composed of 17 authentic standards was used to optimize desorption temperature with respect to sorbent degradation and loading time for calibration. Secondly, we tested the detectability of a complex standard mixture composed of 57 volatiles, most of them common constituents of the body odor of mammals. Moreover, the performance of XAD-2 compared with Tenax TA was assessed as limit of quantitation and linearity for the internal standard mixture and 33 compounds from the complex standard mixture. Volatiles were analyzed in a range between 0.01-∼250ng/tube depending on the compound and material. Lower limits of quantitation were between 0.01 and 3 ng±0.9). Interestingly, we found different kinetics for compound adsorption with XAD-2, and a partially better sensitivity in comparison with Tenax TA. For these analytes, XAD-2 might be recommended as an alternative of Tenax TA for TD/GC-MS analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Analysis of volatile organic compounds in pleural effusions by headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry.

    Science.gov (United States)

    Huang, Zhongping; Zhang, Jie; Zhang, Peipei; Wang, Hong; Pan, Zaifa; Wang, Lili

    2016-07-01

    Headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry was applied to the analysis of volatile organic compounds in pleural effusions. The highly volatile organic compounds were separated successfully with high sensitivity by the employment of a cryotrap device, with the construction of a cold column head by freezing a segment of metal capillary with liquid nitrogen. A total of 76 volatile organic compounds were identified in 50 pleural effusion samples (20 malignant effusions and 30 benign effusions). Among them, 34 more volatile organic compounds were detected with the retention time less than 8 min, by comparing with the normal headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry method. Furthermore, 24 volatile organic compounds with high occurrence frequency in pleural effusion samples, 18 of which with the retention time less than 8 min, were selected for the comparative analysis. The results of average peak area comparison and box-plot analysis showed that except for cyclohexanone, 2-ethyl-1-hexanol, and tetramethylbenzene, which have been reported as potential cancer biomarkers, cyclohexanol, dichloromethane, ethyl acetate, n-heptane, ethylbenzene, and xylene also had differential expression between malignant and benign effusions. Therefore, the proposed approach was valuable for the comprehensive characterization of volatile organic compounds in pleural effusions.

  17. Quantitative determination of volatile organic compounds (VOC) in milk by multiple dynamic headspace extraction and GC-MS.

    Science.gov (United States)

    Ciccioli, Paolo; Brancaleoni, Enzo; Frattoni, Massimiliano; Fedele, Vincenzo; Claps, Salvatore; Signorelli, Federica

    2004-01-01

    A method for the accurate determination of volatile organic compounds (VOC) in milk samples has been developed and tested. It combines multiple dynamic headspace extraction with GC-MS. Absolute amounts of VOC in the liquid phase are obtained by determining the first order kinetic dependence of the stepwise extraction of the analytes and internal standards from the liquid matrix. Compounds released from milk were collected on a train of traps filled with different solid sorbents to cover all components having a number of carbon atoms ranging from 4 to 15. They were analysed by GC-MS after thermal desorption of VOC from the collecting traps. Quantification of VOC in milk was performed using deuterated compounds as internal standards. The method was used to follow seasonal variations of monoterpenes in goat milk and to detect the impact of air pollution on the quality of milk.

  18. Fast online emission monitoring of volatile organic compounds (VOC) in wastewater and product streams (using stripping with direct steam injection).

    Science.gov (United States)

    Schocker, Alexander; Lissner, Bert

    2012-03-01

    Open-loop stripping analysis (also referred to as dynamic headspace) is a very flexible and robust technology for online monitoring of volatile organic compounds in wastewater or coolant. However, the quality and reliability of the analytical results depend strongly on the temperature during the stripping process. Hence, the careful and constant heating of the liquid phase inside the stripping column is a critical parameter. In addition, this stripping at high temperatures extends the spectrum of traceable organics to less volatile and more polar compounds with detection limits down to the ppm-level. This paper presents a novel and promising approach for fast, efficient, and constant heating by the direct injection of process steam into the strip medium. The performance of the system is demonstrated for temperatures up to 75 °C and traces of various hydrocarbons in water (e.g., tetrahydrofuran, methanol, 1-propanol, n-butanol, ethylbenzene).

  19. 40 CFR 60.112a - Standard for volatile organic compounds (VOC).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.112a Section 60.112a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic...

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2014-12-01

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

  2. Characteristics of a non-volatile liquid propellant in liquid-fed ablative pulsed plasma thrusters

    Science.gov (United States)

    Ling, William Yeong Liang; Schönherr, Tony; Koizumi, Hiroyuki

    2017-02-01

    In the past several decades, the use of electric propulsion in spacecraft has experienced tremendous growth. With the increasing adoption of small satellites in the kilogram range, suitable propulsion systems will be necessary in the near future. Pulsed plasma thrusters (PPTs) were the first form of electric propulsion to be deployed in orbit, and are highly suitable for small satellites due to their inherent simplicity. However, their lifetime is limited by disadvantages such as carbon deposition leading to thruster failure, and complicated feeding systems required due to the conventional use of solid propellants (usually polytetrafluoroethylene (PTFE)). A promising alternative to solid propellants has recently emerged in the form of non-volatile liquids that are stable in vacuum. This study presents a broad comparison of the non-volatile liquid perfluoropolyether (PFPE) and solid PTFE as propellants on a PPT with a common design base. We show that liquid PFPE can be successfully used as a propellant, and exhibits similar plasma discharge properties to conventional solid PTFE, but with a mass bit that is an order of magnitude higher for an identical ablation area. We also demonstrate that the liquid PFPE propellant has exceptional resistance to carbon deposition, completely negating one of the major causes of thruster failure, while solid PTFE exhibited considerable carbon build-up. Energy dispersive X-ray spectroscopy was used to examine the elemental compositions of the surface deposition on the electrodes and the ablation area of the propellant (or PFPE encapsulator). The results show that based on its physical characteristics and behavior, non-volatile liquid PFPE is an extremely promising propellant for use in PPTs, with an extensive scope available for future research and development.

  3. Effect of culture of accumulation white mold volatile aromatic compounds in cheese

    OpenAIRE

    Zhukova, Y.; MALOVA V.; KOROL TS.; KOZLOVA L.; PHEDIN PH.

    2012-01-01

    The influence of different cultures of white mold Penicillium caseicolum and Geotrichum candidum on the content of aromatic compounds in a soft cheese have been investigated, methodical approaches to the definition of aromatic compounds by capillary gas chromatography have been developed, a number of characteristic volatile compounds identified and defined that have a specific cheese flavor.

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

    Science.gov (United States)

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

  5. Predicting partitioning of volatile organic compounds from air into plant cuticular matrix by quantum chemical descriptors

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on theoretical linear solvation energy relationship and quantum chemical descriptors computed by AM1 Hamiltonian, a new model is developed to predict the partitioning of some volatile organic compounds between the plant cuticular matrix and air.

  6. Factors that influence the volatile organic compound content in human breath

    NARCIS (Netherlands)

    Blanchet, L.; Smolinska, Agnieszka; Baranska, Agnieszka; Tigchelaar-Feenstra, E.; Swertz, M.; Zhernakova, A.; Dallinga, J. W.; Wijmenga, C.; van Schooten, Frederik J.

    Background. Thousands of endogenous and exogenous volatile organic compounds (VOCs) are excreted in each breath. Inflammatory and deviant metabolic processes affect the level of endogeneous VOCs, which can serve as specific biomarkers for clinical diagnosis and disease monitoring. Important issues

  7. APPLICATION OF MICROWAVE IRRADIATION FOR THE TREATMENT OF ADSORBED VOLATILE ORGANIC COMPOUNDS ON GRANULAR ACTIVATED CARBON

    National Research Council Canada - National Science Library

    A Dehdashti; A Khavanin; A Rezaee; H Assilian; M Motalebi

    2011-01-01

      The purpose of this laboratory scale experimental research was to investigate the application of integrated microwave irradiation and granular activated carbon adsorption for removing volatile organic compounds (VOCs...

  8. Promotion of plant growth by Pseudomonas fluorescens strain SS101 via novel volatile organic compounds

    NARCIS (Netherlands)

    Park, Yong-Soon; Dutta, Swarnalee; Ann, Mina; Raaijmakers, Jos M.; Park, Kyungseok

    2015-01-01

    Abstract Volatile organic compounds (VOCs) from plant growth-promoting rhizobacteria (PGPR) play key roles in modulating plant growth and induced systemic resistance (ISR) to pathogens. Despite their significance, the physiological functions of the specific VOCs produced by Pseudomonas fluorescens

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

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

  11. VOLATILE COMPOUNDS OF WATER-ETHANOLIC EXTRACT OF SATUREJA MONTANA L.

    Directory of Open Access Journals (Sweden)

    A. E. Paliy

    2014-01-01

    Full Text Available We have studied a composition and content of volatile compounds of Satureja montana L. extract. It was established that concentration of volatile compounds in water-ethanol extract of S. montana amounted to 325 mg/100g. The principal component of the extract is carvacrol. It was shown that the extract of Satureja montana represents high biological value

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

    Science.gov (United States)

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

    2014-03-01

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

  13. Effects of trace volatile organic compounds on methane oxidation

    Directory of Open Access Journals (Sweden)

    Wilai Chiemchaisri

    2001-06-01

    Full Text Available The effects of volatile organic compounds (VOCs on methane oxidation in landfill cover soils were examined. The batch experiments were conducted using single and mixed VOCs, such as, dichloromethane (DCM, trichloroethylene (TCE, tetrachloroethylene (PCE, and benzene. The results from all combinations showed a decrease in methane oxidation rate with increase in VOC concentrations. Moreover, inhibition effects of TCE and DCM were found higher than benzene and PCE. The reduction of methane oxidation by benzene and PCE could be attributed to the toxicity effect, whereas TCE and DCM were found to exhibit the competitive-inhibition effect. When the soil was mixed with DCM, no methane oxidation was found. Damage to the cell’s internal membrane was found in a methanotrophic culture exposed to VOC gases which is the attachment site of a key enzyme needed for methane oxidationOs efeitos dos compostos orgânicos voláteis (VOCs na oxidação do metano em camadas superficiais do solo. Os experimentos foram conduzidos usando somente VOCs ou mistura do mesmo, como, diclorometano (DCM, tricloroetileno (TCE, tetracloroetileno (PCE, e benzeno. Os resultados de todas as combinações mostraram uma diminuição na taxa da oxidação do metano com aumento nas concentrações de VOC. Além disso, os efeitos da inibição de TCE e de DCM foram mais elevados do que do benzeno e PCE. A redução da oxidação do metano pelo benzeno e PCE poderia ser atribuída ao efeito da toxicidade, visto que TCE e DCM exibiram o efeito de competição-inibição. Quando o solo foi misturado com o DCM, nenhuma oxidação do metano foi encontrada. Os danos à membrana interna celular foi observada em uma cultura metanotrófica exposta aos gases de VOC que é o local de ligação de uma enzima chave necessário para a oxidação do metano.

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

    Science.gov (United States)

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

    2013-10-01

    Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) to the atmosphere. A small number of studies have measured VOC emission from silage, but not enough is known about the processes involved to accurately quantify emission rates and identify practices that could reduce emissions. Through a literature review, we have focused on identifying the most important compounds emitted from corn silage (the most common type of silage in the US) and the sources of these compounds by quantifying their production and emission potential in silage and describing production pathways. We reviewed measurements of VOC emission from silage and assessed the importance of individual silage VOCs through a quantitative analysis of VOC concentrations within silage. Measurements of VOC emission from silage and VOCs present within silage indicated that alcohols generally make the largest contribution to emission from corn silage, in terms of mass emitted and potential ozone formation. Ethanol is the dominant alcohol in corn silage; excluding acids, it makes up more than half of the mean mass of VOCs present. Acids, primarily acetic acid, may be important when emission is high and all VOCs are nearly depleted by emission. Aldehydes and esters, which are more volatile than acids and alcohols, are important when exposure is short, limiting emission of more abundant but less volatile compounds. Variability in silage VOC concentrations is very high; for most alcohols and acids, tolerance intervals indicate that 25% of silages have concentrations a factor of two away from median values, and possibly much further. This observation suggests that management practices can significantly influence VOC concentrations. Variability also makes prediction of emissions difficult. The most important acids, alcohols, and aldehydes present in silage are probably produced by bacteria (and, in the case of ethanol, yeasts) during fermentation and

  15. Evaporation losses and dispersion of volatile organic compounds from tank farms.

    Science.gov (United States)

    Howari, Fares M

    2015-05-01

    The present study is an application of a Gaussian dispersion model to evaluate volatilization losses from tank farms. It reports methodology to estimate evaporation losses of volatile organic compounds (VOCs) from organic liquid in storage tanks. This study used fixed roof and floating roof equations for breathing and working losses. Total loss, the breathing loss, vapor pressure, molecular weight of the product, tank diameter, diurnal temperature, paint factor, tank capacity, and number of turnovers were considered and factored in the calculation. AERMOD and ALOHA softwares were used to simulate the dispersion of VOCs under normal and accidental scenarios. For the modeling purposes, meteorological data such as annual average ambient temperature, annual average atmospheric pressure, daily minimum ambient temperature, daily maximum ambient temperature, solar insulation factor, and average wind speed were included as input in the calculation and modeling activities. The study took place in Sharjah Emirate in United Arab Emirates, which borders Dubai to the south and Ajman to the north, and the three form a conurbation. The reported method was used to estimate evaporation losses for baseline and hypothetical leak scenarios. Results of this research show that liquid storage tanks in the study area emit a low concentration of VOC under the studied and assumed conditions, e.g., new tanks with high performance sealing as well as the noted earlier climatic conditions. The dispersion of those concentrations is controlled by the prevailing wind direction. The predicted VOCs concentrations were within the range of the measured VOCs values in air. The study found that the spatial distributions of the predicted concentration attenuate with time and distance. Under the reported accidental spill scenario, the Gaussian model indicates that the danger area starts within the zone of less than 10 m. The danger area is subjected to flame pockets, and the VOC concentrations in this

  16. On the volatile flavour compounds of cooked trassi, a cured shrimp paste condiment of the Far East

    NARCIS (Netherlands)

    Soedarmo Moeljohardjo, D.

    1972-01-01

    The volatile compounds of cooked trassi, a cured shrimp paste condiment of the Far East have been studied. The techniques of volatiles isolation, concentration, fractionation as well as methods of identification have been described. 138 volatile compounds, which included 16 hydrocarbons, 7 alcohols,

  17. On the volatile flavour compounds of cooked trassi, a cured shrimp paste condiment of the Far East

    NARCIS (Netherlands)

    Soedarmo Moeljohardjo, D.

    1972-01-01

    The volatile compounds of cooked trassi, a cured shrimp paste condiment of the Far East have been studied. The techniques of volatiles isolation, concentration, fractionation as well as methods of identification have been described. 138 volatile compounds, which included 16 hydrocarbons, 7

  18. Analysis of Volatile Compounds from Solanumbetaceum Cav. Fruits from Panama by Head-Space Micro Extraction

    Directory of Open Access Journals (Sweden)

    Armando A. Durant

    2013-01-01

    Full Text Available The characterization of the volatile compounds of two varieties of Solanum betaceum Cav. by means of headspace solid-phase microextraction (HS-SPME coupled with gas chromatography-mass spectrometry ( GC-MS i s presented. The HS-SPME method for extraction of the volatiles compounds was optimized by using a 2 3 central composite design. Maximum extraction of volatile compounds was achieved by using a divinylbenzene-carboxen-polydimethylsiloxane (DVB/CAR/PDMS fiber, extraction temperature 76° C, incubation time 44 min, and extraction time of 46 min. The main types of compounds detected in both varieties are terpenoids, followed by aromatics, esters, and aldehydes. Golden-yellow cultivars contained higher levels of esters and terpenes, while the reddish-purple variety contained a significant amount of aromatic compounds. The data structure of the chemical information obtained as well as the relationship between variables was evaluated by means of principal component analysis and cluster analysis.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  2. Characterization and extraction of volatile compounds from pineapple (Ananas comosus L. Merril processing residues

    Directory of Open Access Journals (Sweden)

    Lília Calheiros de Oliveira Barretto

    2013-12-01

    Full Text Available The aim of this study was to extract and identify volatile compounds from pineapple residues generated during concentrated juice processing. Distillates of pineapple residues were obtained using the following techniques: simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by the solid-phase microextraction technique. The volatile compounds were identified in a system of high resolution gas chromatography system coupled with mass spectrometry using a polyethylene glycol polar capillary column as stationary phase. The pineapple residues constituted mostly of esters (35%, followed by ketones (26%, alcohols (18%, aldehydes (9%, acids (3% and other compounds (9%. Odor-active volatile compounds were mainly identified in the distillate obtained using hydrodistillation by passing nitrogen gas, namely decanal, ethyl octanoate, acetic acid, 1-hexanol, and ketones such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, and γ-dodecalactone. This suggests that the use of an inert gas and lower temperatures helped maintain higher amounts of flavor compounds. These data indicate that pineapple processing residue contained important volatile compounds which can be extracted and used as aroma enhancing products and have high potential for the production of value-added natural essences.

  3. Effect of {gamma}-irradiation on the volatile compounds of medicinal herb, Paeoniae Radix

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Sung-Lye; Hwang, In-Min; Ryu, Keun-Young; Jung, Min-Seok [Department of Food and Nutrition, Chosun University (Korea, Republic of); Seo, Hye-young [Korea Food Research Institute (Korea, Republic of); Kim, Hee-Yeon [Korea Food and Drug Administration (Korea, Republic of); Song, Hyun-Pa; Kim, Jae-Hun; Lee, Ju-Woon; Byun, Myung-Woo [Advanced Radiation Technology Institute, KAERI, Jeongeup 580-185 (Korea, Republic of); Kwon, Joong-Ho [Department of Food Science and Technology, Kyungpook National University (Korea, Republic of); Kim, Kyong-Su [Korea Food Research Institute (Korea, Republic of)], E-mail: kskim@chosun.ac.kr

    2009-07-15

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

  4. The Volatile Compounds of the Elderflowers Extract and the Essential Oil

    Directory of Open Access Journals (Sweden)

    Hale Gamze Ağalar

    2017-09-01

    Full Text Available Sambucus nigra L. (Caprifoliaceae known as ‘black elder’ is widely used as both food and medicinal plant in Europe. Elderflowers are consumed as herbal tea and its gargle has benefits in respiratory tract illnesses such as cough, influenza, inflammation in throat. In this study, we aimed to show the compositions of the volatile compounds-rich in extract and the essential oil of the elderflowers cultivated in Kütahya, Turkey. HS-SPME (Headspace-Solid Phase MicroExtraction technique was employed to trap volatile compounds in the hexane extract of dried elderflowers. The volatile compounds in the essential oil from elderflowers isolated by hydrodistillation were analyzed GC and GC-MS systems, simultaneously. Results for the n-hexane extract: thirty volatile compounds were identified representing 84.4% of the sample. cis-Linalool oxide (27.3% and 2-hexanone (10.5% were found to be main compounds of the n-hexane extract. Results for the essential oil: fifteen volatile compounds were identified representing 90.4% of the oil. Heneicosane (18.8%, tricosane (17.3%, nonadecane (13% and pentacosane (10.3% were the major compounds of the oil.

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

    Directory of Open Access Journals (Sweden)

    Ewa Górska

    2017-05-01

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

  6. Atmospheric fate of non volatile and ionizable compounds

    DEFF Research Database (Denmark)

    Franco, Antonio; Hauschild, Michael Zwicky; Jolliet, Olivier

    2011-01-01

    A modified version of theMultimedia Activity Model for Ionics MAMI, including two-layered atmosphere,air–water interface partitioning, intermittent rainfall and variable cloud coverage was developed to simulate the atmospheric fate of ten low volatility or ionizable organic chemicals. Probabilist...

  7. Multiclass semi-volatile compounds determination in wine by gas chromatography accurate time-of-flight mass spectrometry.

    Science.gov (United States)

    Rodríguez-Cabo, T; Rodríguez, I; Ramil, M; Silva, A; Cela, R

    2016-04-15

    The performance of gas chromatography (GC) with accurate, high resolution mass spectrometry (HRMS) for the determination of a group of 39 semi-volatile compounds related to wine quality (pesticide residues, phenolic off-flavours, phenolic pollutants and bioactive stilbenes) is investigated. Solid-phase extraction (SPE) was used as extraction technique, previously to acetylation (phenolic compounds) and dispersive liquid-liquid microextraction (DLLME) concentration. Compounds were determined by GC coupled to a quadrupole time-of-flight (QTOF) MS system through an electron ionization (EI) source. The final method attained limits of quantification (LOQs) at the very low ng mL(-1) level, covering the range of expected concentrations for target compounds in red and white wines. For 38 out of 39 compounds, performance of sample preparation and determination steps were hardly affected by the wine matrix; thus, accurate recoveries were achieved by using pseudo-external calibration. Levels of target compounds in a set of 25 wine samples are reported. The capabilities of the described approach for the post-run identification of species not considered during method development, without retention time information, are illustrated and discussed with selected examples of compounds from different classes.

  8. The storage stability of biogenic volatile organic compounds (BVOCs) in polyester aluminum bags

    Science.gov (United States)

    Ahn, Jeong-Hyeon; Deep, Akash; Kim, Ki-Hyun

    2016-09-01

    In this study, the sorptive loss properties of biogenic volatile organic compounds (BVOCs) in polyester aluminum bags were investigated as a function of storage duration. To this end, the relative recovery of gas phase standards of BVOCs, obtained via vaporization of liquid phase standards, was computed by calibrating their standards (response factors: RF) represnting each phase. Accordingly, the results indicated either slight loss (-5.59% (isoprene), -2.39% (camphene), -1.69% ((R)-(+)-limonene), -0.88% (p-cymene)) or gain (1.47% (γ-terpinene), 2.27% (α-terpinene), 2.63% (α-phellandrene), 2.73% ((+)-3-carene), 3.93% ((+)-β-pinene), and 5.98% ((+)-α-pinene)). Through comparison of the calibration results across storage time, the temporal stability of BVOCs was assessed. Longer BVOC storage time in polyester aluminum (PEA) bags lowered the relative recovery of BVOCs. The relative loss of BVOCs, if calculated in terms of mean bag standard RF ratios (relative to liquid standard) across elapsed time, decreased systematically: 0.99 ± 0.05 (0 h), 0.88 ± 0.06 (24 h), 0.66 ± 0.11 (72 h), and 0.62 ± 0.14 (120 h). It is thus recommended to complete the analysis of BVOC in PEA bags within 24 h of sample acquisition. As such, it is important to apply appropriate sampling approaches with a proper storage plan when measuring ambient BVOCs collected by bag sampling methods.

  9. Effects of airborne volatile organic compounds on plants.

    Science.gov (United States)

    Cape, J N

    2003-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    P. K. Misztal

    2014-03-01

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

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

    Science.gov (United States)

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

    2010-08-01

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

  12. Volatile organic compound (VOC) determination in working atmospheres; Determinacion de compuestos organicos volatiles (VOC) en ambiente laboral

    Energy Technology Data Exchange (ETDEWEB)

    Blass A, Georgina; Panama T, Luz A; Corrales C, Deyanira [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2003-07-01

    The present work describes, in a synthesized way, the implementation and application of procedures based on the normativity related to the subject of the volatile organic compounds (Volatile Organic Compounds VOC), that allow to sample, quantify and evaluate the present contamination in the working atmosphere of a refinery due to the fugitive emissions of VOC and other substances. In accordance with the corresponding normativity, more than 189 organic compounds denominated dangerous air polluting agents (Hazardous Air Pollutants, HAP) can be found in a working atmosphere, but they are the 11 main HAP that can be found in a refinery. In the present article the work made for the sampling and quantification of 5 of the 11 dangerous polluting agents of the air: benzene, toluene, xylene, iso-octane and naphthalene. [Spanish] El presente trabajo describe, de manera sintetizada, la implementacion y aplicacion de procedimientos basados en la normatividad relacionada al tema de los compuestos organicos volatiles (Volatil Organic Compounds, VOC), que permiten muestrear, cuantificar y evaluar la contaminacion presente en el ambiente laboral de una refineria debido a las emisiones fugitivas de VOC y otras sustancias. De acuerdo con la normatividad correspondiente, mas de 189 compuestos organicos denominados contaminantes peligrosos del aire (Hazardous Air Pollutants, HAP), pueden ser encontrados en un ambiente laboral, pero son 11 los principales HAP que pueden ser hallados en una refineria. En el presente articulo se informa el trabajo realizado para el muestreo y cuantificacion de 5 de los 11 contaminantes peligrosos del aire: benceno, tolueno, xileno, iso-octano y naftaleno.

  13. Characterization of Volatile Flavor Compounds in Chinese Rice Wine Fermented from Enzymatic Extruded Rice.

    Science.gov (United States)

    Xu, Enbo; Long, Jie; Wu, Zhengzong; Li, Hongyan; Wang, Fang; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan

    2015-07-01

    Enzymatic extrusion, instead of traditional steam cooking, to treat rice is an efficient and alternative pretreatment for Chinese rice wine fermentation. In order to determine the formation of volatiles in enzymatic extrusion-processed rice wine (EE), and to confirm its characteristic flavor compounds, headspace solid-phase micro-extraction followed by GC-MS was used. A total of 66 volatile compounds were identified in EE. During fermentation, most volatiles generated from enzymatic extruded rice had the similar trends with those from steam-cooked rice, but the differences in the concentration of volatiles indicated a changed balance of flavors release caused by enzymatic extrusion. Besides, the concentrations and sorts of volatiles in EEs fermented from different rice particle sizes, were not dramatically different. By principal component analysis, EE could be distinctly separated from other traditional Chinese rice wines according to its characteristic volatiles, namely, 2-heptanol, 1-octen-3-ol, ethyl 4-hydroxybenzoate, methylpentyl 2-propenoate, γ-hexalactone, and 4-vinylguaiacol. Enzymatic extrusion liquefaction has been a popular thermal treatment for cereals, and gradually being applied in fermentation and liquor-making industry all over the world. The characterization of volatile flavor compounds in Chinese rice wine processed by enzymatic extrusion liquefaction pretreatment, might be made use not only for a better understanding of this new-type rice wine, but for the further utilization of enzymatic extrusion in other wine or alcohol production as well. © 2015 Institute of Food Technologists®

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

    Science.gov (United States)

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

    2013-05-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    DEFF Research Database (Denmark)

    Liu, Jing; Arneborg, Nils; Toldam-Andersen, Torben

    2017-01-01

    : The different non-Saccharomyces strains and cool-climate grape cultivars produced wines with a distinctive aromatic profile. A total of 67 volatile compounds were identified, including 43 esters, 14 alcohols, five acids, two ketones, a C13-norisoprenoid, a lactone and a sulfur compound. The use of M. viticola...

  18. Analysis of volatile organic compound from Elaeis guineensis inflorescences planted on different soil types in Malaysia

    Science.gov (United States)

    Muhamad Fahmi, M. H.; Ahmad Bukhary, A. K.; Norma, H.; Idris, A. B.

    2016-11-01

    The main attractant compound for Eleidobius kamerunicus to male spikelet Elaeis guineensis (oil palm) were determined by analyzing volatile organic compound extracted from E. guineenses inflorescences planted on different soil types namely peat soil, clay soil and sandy soil. Anthesizing male oil palm inflorescences were randomly choosen from palm aged between 4-5 years old age. Extraction of the volatiles from the oil palm inflorescences were performed by Accelerated Solvent Extraction method (ASE). The extracted volatile compound were determined by using gas chromatography-mass spectrometry. Out of ten identified compound, estragole was found to be a major compound in sandy soil (37.49%), clay soil (30.71%) and peat soil (27.79%). Other compound such as 9,12-octadecadieonic acid and n-hexadecanoic acid were found as major compound in peat soil (27.18%) and (7.45%); sandy soil (14.15 %) and (9.31%); and clay soil (30.23%) and (4.99%). This study shows that estragole was the predominant volatile compound detected in oil palm inflorescences with highly concentrated in palm planted in sandy soil type.

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

    OpenAIRE

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

    2014-01-01

    The aim of this study is to examine the influences of spices on the amounts and compositions of volatile compounds released from cooked beef patty. Beef patty with 0.5% of spice (nutmeg, onion, garlic, or ginger powder, w/w) was cooked by electronic pan until they reached an internal temperature of 75℃. A total of 46 volatile compounds (6 alcohols, 6 aldehydes, 5 hydrocarbons, 6 ketones, 9 sulfur compounds, and 14 terpenes) from cooked beef patties were detected by using purgeand- trap GC/MS....

  20. Liquidity, Volatility and Stock Price Adjustment: Evidence from Seasoned Equity Offerings in an Emerging Market

    OpenAIRE

    Chia-Cheng Ho; Chin-Chuan Lee; Chien-Ting Lin; C. Edward Wang

    2005-01-01

    Using data from the Taiwanese stock market, an emerging market, this paper documents positive changes in liquidity and volatility around seasoned equity offerings (SEOs). These findings are consistent with the uncertain signal hypothesis that investors with diverse views on the information content of SEOs are likely to induce larger trading activity and subsequent higher stock return volatility. We also provide direct evidence that changes in liquidity is positively associated with stock pric...

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

    Science.gov (United States)

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

    2016-01-15

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

  2. Associations of Volatile Compounds with Sensory Aroma and Flavor: The Complex Nature of Flavor

    Directory of Open Access Journals (Sweden)

    Edgar Chambers IV

    2013-04-01

    Full Text Available Attempts to relate sensory analysis data to specific chemicals such as volatile compounds have been frequent. Often these associations are difficult to interpret or are weak in nature. Although some difficulties may relate to the methods used, the difficulties also result from the complex nature of flavor. For example, there are multiple volatiles responsible for a flavor sensation, combinations of volatiles yield different flavors than those expected from individual compounds, and the differences in perception of volatiles in different matrices. This review identifies some of the reasons sensory analysis and instrumental measurements result in poor associations and suggests issues that need to be addressed in future research for better understanding of the relationships of flavor/aroma phenomena and chemical composition.

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

    Science.gov (United States)

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

    2012-06-10

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

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

    Science.gov (United States)

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

    2014-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, Casey C.; DiSalvo, Rick; Boylan, John [Stoller LMS Team, 11025 Dover Street, Suite 1000, Westminster, CO 80021 (United States)

    2013-07-01

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

  6. Changes in volatile compounds of gamma-irradiated fresh cilantro leaves during cold storage.

    Science.gov (United States)

    Fan, Xuetong; Sokorai, Kimberly J B

    2002-12-18

    Consumption of salsas and dishes containing cilantro has been linked to several recent outbreaks of food-borne illness due to contamination with human pathogens. Ionizing irradiation can effectively eliminate food-borne pathogens from various vegetables including cilantro. However, the effect of irradiation on aroma of fresh cilantro is unknown. This study was conducted to investigate the effect of irradiation on volatile compounds of fresh cilantro leaves. Fresh cilantro leaves (Coriandrum sativum L) were irradiated with 0, 1, 2, or 3 kGy gamma radiation and then stored at 3 degrees C up to 14 days. Volatile compounds were extracted using solid-phase microextraction (SPME), followed by gas chromatographic separation and mass spectra detection at 0, 3, 7, and 14 days after irradiation. Most of the volatile compounds identified were aldehydes. Decanal and (E)-2-decenal were the most abundant compounds, accounting for more than 80% of the total amount of identified compounds. The amounts of linalool, dodecanal, and (E)-2-dodecenal in irradiated samples were significantly lower than those in nonirradiated samples at day 14. However, the most abundant compounds [decanal and (E)-2-decenal] were not consistently affected by irradiation. During storage at 3 degrees C, the amount of most aldehydes peaked at 3 days and then decreased afterward. Our results suggest irradiation of fresh cilantro for safety enhancement at doses up to 3 kGy had minimal effect on volatile compounds compared with the losses that occurred during storage.

  7. Phytoactivity of secondary compounds in aromatic plants by volatile and water-soluble ways of release

    OpenAIRE

    A. S. Dias; Dias, L. S.

    2005-01-01

    Phytoactivity should be expected as a generalized trait of secondary plant compounds if their primary role is defence against co-occurring plants, and volatilization should be their predominant way of release in dry climates while in wet climates water leaching should prevail. Bioassays were designed to compare the ability of volatiles and water-solubles of four aromatic species thriving in dry environments (Cistus salvifolius L., Foeniculum vulgare Miller, Myrtus communis L., and Rosmarinus ...

  8. Antibacterial and insecticidal activity of volatile compounds of three algae species of Oman Sea

    OpenAIRE

    Pasdaran, Ardalan; Hamedi, Azadeh; Mamedov, Nazim A.

    2016-01-01

    Many of the volatile oils showed important biologicaland pharmacological activities, these compounds as part of the traditionalmedicine in many cultures used as long time. Potencies of them caused thesenatural products gained many scientific researches in felid of naturalproducts. The volatile oils of Actinotrichiafragilis (Forsskål) Børgesen,Liagora ceranoides J.V.Lamouroux and Colpomenia sinuosa (Mertensex Roth) Derbes and. Solier were extracted by hydrodistillation. Thesevolatile oils were...

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

    Science.gov (United States)

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

    2011-07-01

    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 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.

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

    Science.gov (United States)

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

    2016-07-22

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

  11. 78 FR 62451 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of 2,3,3,3...

    Science.gov (United States)

    2013-10-22

    ... AGENCY 40 CFR Part 51 RIN 2060-AR70 Air Quality: Revision to Definition of Volatile Organic Compounds.... SUMMARY: The EPA is taking final action to revise the regulatory definition of volatile organic compounds... those organic compounds of carbon that form ozone through atmospheric photochemical reactions....

  12. A variety of volatile compounds as markers in unifloral honey from dalmatian sage (Salvia officinalis L.).

    Science.gov (United States)

    Jerković, Igor; Mastelić, Josip; Marijanović, Zvonimir

    2006-12-01

    Volatile compounds of unifloral Salvia officinalis L. honey has been investigated for the first time. The botanical origin of ten unifloral Salvia honey samples has been ascertained by pollen analysis (the honey samples displayed 23-60% of Salvia pollen). Fifty-four volatile compounds were identified by GC and GC/MS in ten Salvia honey extracts obtained by ultrasound-assisted extraction (USE) with pentane/Et(2)O 1 : 2. The yield of isolated volatiles varied from 25.7 to 30.5 mg kg(-1). Salvia honey could be distinguished on the basis of the high percentage of benzoic acid (6.4-14.8%), and especially phenylacetic acid (5.7-18.4%). Minor, but floral-origin important volatiles were identified such as shikimate pathway derivatives, 'degraded-carotenoid-like' structures (3,5,5-trimethylcyclohex-2-ene derivatives) and 2,6,6-trimethylcyclohex-2-ene derivatives. Compounds from other metabolic pathways such as aliphatic acids and higher linear hydrocarbons, as well as heterocycles (pyrans, furans, and pyrroles), were also present. Most of the identified compounds do not constitute specific Salvia honey markers, due to their presence in honeys of other botanical origins; however, their ratio in different honeys could be useful to distinguish floral origin. Salvia-honey volatile markers were: benzoic acid, phenylacetic acid, p-anisaldehyde, alpha-isophorone, 4-ketoisophorone, dehydrovomifoliol, 2,6,6-trimethyl-4-oxocyclohex-2-ene-1-carbaldehyde, 2,2,6-trimethylcyclohexane-1,4-dione, and coumaran.

  13. Characterisation of volatile organic compounds in stemwood using solid-phase microextraction.

    Science.gov (United States)

    Wajs, A; Pranovich, A; Reunanen, M; Willför, S; Holmbom, B

    2006-01-01

    Solid-phase microextraction (SPME), hydrodistillation and dynamic headspace combined with GC and GC-MS were applied and compared for the analysis of volatile organic compounds (VOCs) from coniferous wood. The SPME conditions (type of fibre, size of wood sample, temperature and exposure time) were optimised, and more than 100 VOCs and semi-volatile compounds extracted and identified from the sapwood and heartwood of Norway spruce (Picea abies). The total number of mono- and sesquiterpenes eluted and identified was similar for the SPME and hydrodistillation methods, but more semi-volatile compounds were released by hydrodistillation. By applying dynamic headspace at room temperature, it was possible to analyse only the most volatile compounds. The qualitative composition of VOCs was similar in spruce sapwood and heartwood, although Z-beta-ocimene occurred only in sapwood while fenchol was present only in heartwood. SPME sampling coupled with GC, applied here to the analysis of VOCs released from stemwood of firs for the first time, is a convenient, sensitive, fast, solvent-free and simple method for the determination of wood volatiles. The technique requires much smaller sample amounts compared with hydrodistillation, and the total amount of VOCs extracted and identified is higher than that obtained by hydrodistillation or dynamic headspace. The relative ratios of the main mono- and sesquiterpenes and -terpenoids were similar using the SPME-GC and hydrodistillation methods.

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

    Science.gov (United States)

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

    2016-04-01

    Among Volatile Organic Compounds (VOC), the mono-aromatic compounds so-called BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) and the intermediate volatility organic compounds (IVOC) with C>12 are two remarkable chemical families having high impact on health, as well as on the production of secondary pollutants like secondary organic aerosols (SOA) and ozone. However, the nature and relative importance of their sources and, consequently, their impact on SOA formation at urban scale is still under debate. On the one hand, BTEX observations in urban areas of northern mid-latitudes do not reconcile with emission inventories; the latter pointing to solvent use as the dominant source compared to traffic. Moreover, a recent study by Borbon et al. (2013) has shown an enrichment in the C7-C9 aromatic fraction in Paris atmosphere by a factor of 3 compared to other cities. Causes would be: (i) differences in gasoline composition, (ii) differences in vehicle fleet composition, and (iii) differences in solvent use related sources. On the other hand, many smog chamber studies have highlighted IVOCs as important SOA precursors over the last decade but their origin and importance in urban areas relative to other precursors like BTEX is still poorly addressed. Here we combined large VOC datasets to investigate sources of BTEX and IVOC in contrasted urban areas by source-receptor approaches and laboratory experiments. Ambient data include multi-site speciated ambient measurements of C2 to C17 VOCs (traffic, urban background, and tunnel) from air quality networks (ie. AIRPARIF in Paris) and intensive field campaigns (MEGAPOLI-Paris, TRANSEMED in Beirut and Istanbul, PHOTOPAQ in Brussels). Preliminary results for Paris suggest that traffic dominates BTEX concentrations while traffic and domestic heating for IVOC (>70%). In parallel, the detailed composition of the fuel liquid phase was determined at the laboratory for typical fuels distributed in Ile de France region (diesel, SP95

  15. Chemical composition and volatile compounds in the artisanal ...

    African Journals Online (AJOL)

    Araceli

    2012-09-27

    Sep 27, 2012 ... ends, the fermented product is transferred to copper ..... Clostridium bacteria or Kloeckera spp. yeast .... Evolution of chemical compounds during fermentation of A. angustifolia musts with and without addition of ammonium ...

  16. Surface-tension-driven convection in pure liquid layers evaporating into ambient air: influence of liquid volatility

    Science.gov (United States)

    Chauvet, Fabien; Dehaeck, Sam; Colinet, Pierre

    2011-11-01

    The spontaneous surface-tension-driven convective patterns induced by evaporation of a pure liquid layer are studied experimentally. A volatile liquid layer placed in a cylindrical container is left free to evaporate into air at rest under ambient conditions. The thermal dynamics of the evaporating liquid layer is visualized using an infrared camera. Evaporation rate and liquid thickness are measured by weighting. We focus on the transition between the convective state and the conductive state appearing at a certain instant during the drying of the liquid layer. The critical Marangoni number Mac associated to this transition is estimated from evaporation rate and layer thickness measurements at this instant. The effect of the evaporation rate on Mac and kc (the critical wavenumber) has been investigated by changing the container height and, separately, the effect of the liquid volatility has been studied by using different liquids. Interestingly, it appears that Mac does not depend on the evaporation rate while it depends strongly on the liquid volatility. Given the typical uncertainties associated with liquid properties, a quite reasonable agreement is found with a ``one-sided'' linear stability analysis of this problem. Supported by ESA & BELSPO, by the EU, by ULB, and by FRS - FNRS.

  17. Volatile compounds of black cumin seeds (Nigella sativa L.) from microwave-heating and conventional roasting.

    Science.gov (United States)

    Kiralan, Mustafa

    2012-04-01

    The volatile compounds in raw, conventionally roasted and microwave roasted black cumin (Nigella sativa L.) seeds at 0.45 kW for 2, 4, and 8 min, were analyzed by headspace-SPME gas chromatography-mass spectrometry. Among the 38 volatile compounds identified, the major compounds were thymoquinone and p-cymene in all samples. The levels of these compounds decreased with roasting. However, concentrations of pyrazines and furans increased significantly as a result of roasting and these compounds may affect the flavor of roasted black cumin seeds. Methyl pyrazine and 2,5-dimethylpyrazine were major pyrazines, formed at high concentration in seeds roasted for 8 min and in conventional roasting.

  18. Sensory and Physiological Effects on Humans of Combined Exposures to Air Temperatures and Volatile Organic Compounds

    DEFF Research Database (Denmark)

    Mølhave, Lars; Liu, Zunyong; Jørgensen, Anne Hempel

    1993-01-01

    Ten healthy humans were exposed to combinations of volatile organic compounds (VOCs) and air temperature (0 mg/m3 and 10 mg/m3 of a mixture of 22 volatile organic compounds and 18, 22 and 26° C). Previously demonstrated effects of VOCs and thermal exposures were replicated. For the first time nasal...... cross-sectional areas and nasal volumes, as measured by acoustic rhinometry, were shown to decrease with decreasing temperature and increasing VOC exposure. Temperature and pollutant exposures affected air quality, the need for more ventilation, skin humidity on the forehead, sweating, acute sensory...

  19. Safety of food contact silicone rubber: Liberation of volatile compounds from soothers and teats

    DEFF Research Database (Denmark)

    Lund, Kirsten H.; Petersen, Jens Højslev

    2002-01-01

    The release of volatile compounds from soothers and teats made from silicone rubber has been investigated. Firstly, measurements of the total release of volatiles were performed according to the method in the draft European standard (CEN). Weight losses of 0.17-0.80% after four hours at 200 degre......) detectors. The main compounds were siloxane oligomers and aliphatic hydrocarbons. One teat released about 0.1 mg diethyl phtalate (DEP), which is considered to be quite a high quantity. Limited amounts of the antioxidant 3,5-di-t-butyl-4-hydroxytoluene (BHT) were found in most samples....

  20. Synthesis of novel ionic liquids from lignin-derived compounds

    Energy Technology Data Exchange (ETDEWEB)

    Socha, Aaron; Singh, Seema; Simmons, Blake A.; Bergeron, Maxime

    2017-09-19

    Methods and compositions are provided for synthesizing ionic liquids from lignin derived compounds comprising: contacting a starting material comprising lignin with a depolymerization agent to depolymerize the lignin and form a mixture of aldehyde containing compounds; contacting the mixture of aldehyde containing compounds with an amine under conditions suitable to convert the mixture of aldehyde containing compounds to a mixture of amine containing compounds; and contacting the mixture of amine containing compounds with an acid under conditions suitable to form an ammonium salt, thereby preparing the ionic liquid.

  1. Diurnal and seasonal variability of gasoline-related volatile organic compound emissions in Riverside, California.

    Science.gov (United States)

    Gentner, Drew R; Harley, Robert A; Miller, Angela M; Goldstein, Allen H

    2009-06-15

    On- and off-road mobile sources are the dominant contributors to urban anthropogenic volatile organic compound (AVOC) emissions. Analyses of gasoline samples from California for both summer and winter indicate significant differences in liquid fuel and vapor chemical composition due to intentional seasonal adjustments. Ambient concentrations of 55 VOCs were measured via in situ gas chromatography in the 2005 Study of Organic Aerosols at Riverside (SOAR) during both summer and fall. A chemical mass balance analysis was used to differentiate vapor pressure-driven VOC emissions from other motor vehicle-related emissions such as tailpipe exhaust. Overall, fuel vapor emissions accounted for 31 +/- 2% of gasoline-related VOC in Riverside; California's emission factor model similarly estimates 31% of gasoline-related VOC emissions are fuel vapor. The diurnal pattern of vapor pressure-driven VOC source contributions is relatively stable around 10 microg/m3, while whole gasoline (i.e., tailpipe) contributions peak at approximately 60 microg/m3 during the morning commute. There is no peak in whole gasoline source contributions during the afternoon, due to rapid dilution associated with high mixing heights and wind speeds in the Riverside area. The relationship between estimated gasoline-related VOC and observed carbon monoxide concentrations in this study is similar to California's 2005 emission inventory; we calculated a VOC to CO mass ratio of 0.086 +/- 0.006 (95% CI) compared to 0.097 in the emission inventory for all gasoline-related sources.

  2. Identification and quantitation of volatile organic compounds emitted from dairy silages and other feedstuffs.

    Science.gov (United States)

    Malkina, Irina L; Kumar, Anuj; Green, Peter G; Mitloehner, Frank M

    2011-01-01

    High ground-level ozone continues to be an important human, animal, and plant health impediment in the United States and especially in California's San Joaquin Valley (SJV). According to California state and regional air quality agencies, dairies are one of the major sources of volatile organic compounds (VOCs) in the SJV. A number of recently conducted studies reported emissions data from different dairy sources. However, limited data are currently available for silage and otherfeed storages on dairies, which could potentially contribute to ozone formation. Because the impact of different VOCs on ozone formation varies significantly from one molecular species to another, detailed characterization of VOC emissions is essential to include all the important contributors to atmospheric chemistry and especially atmospheric reactivity. The present research study identifies and quantifies the VOCs emitted from various silages and other feedstuffs. Experiments were conducted in an environmental chamber under controlled conditions. Almost 80 VOCs were identified and quantified from corn (Zea mays L.), alfalfa (Medicago sativa L.),and cereal (wheat [Triticum aestivum L.] and oat [Avena sativava L.] grains) silages, total mixed ration (TMR), almond (Amygdalus communis L.) shells and hulls using gas chromatography-mass spectrometry and high performance liquid chromatography. The results revealed high concentrations of emitted alcohols and other oxygenated species. Lower concentrations of highly reactive alkenes and aldehydes were also detected. Additional quantitation and monitoring of these emissions are essential for assessment of and response to the specific needs of the regional air quality in the SJV.

  3. Integrated gas chromatography for ultrafast analysis of volatile organic compounds in air.

    Science.gov (United States)

    Zhang, Yanggang; Wu, Dapeng; Yan, Xiaohui; Ding, Kun; Guan, Yafeng

    2016-07-01

    An integrated instrumentation of a cryogenic microtrap-thermal desorption-low thermal mass (LTM) fast gas chromatographic (GC) system had been designed and evaluated for the ultrafast enrichment and separation of trace amounts of highly volatile organic compounds (VOCs) in air. The LTM fast GC column was wrapped uniformly on outer surface of a thin metal heating cylinder of 65mm O.D. and 0.5mm in thickness. Both of microtrap and LTM column could be rapidly cooled by liquid CO2 down to -35°C, and heated by resistive heating. A 10m×100µm i.d. micro-bore capillary column was used in the LTM GC column module to provide a high separation speed. Key operational parameters, including adsorbent mass, trapping temperature, thermal desorption temperature and injection time were optimized. Under the optimized condition, the 39 species of TO-14 VOCs were well resolved and quantified in less than 3min. The detection limits were in the range of 8 ppt-0.22 ppb at sampling volume of 50mL and trapping temperature of -10°C. The average peak width was 0.9s, and the peak capacity of ~150 (at unit resolution) was obtained. The applicability of the setup was evaluated by analyzing three real environmental samples, where some typical VOCs at sub ppb level were detected.

  4. Evolution of volatile compounds in gluten-free bread: From dough to crumb.

    Science.gov (United States)

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

    2017-07-15

    Understanding the evolution of volatile compounds from dough to crumb is necessary in order to improve the weak aroma of gluten-free breads. Additionally, sensitive analytical methods are required to detect small changes. In the present study, a solvent extraction method combined with GC/MS was selected to examine the evolution of 31 principal volatile compounds from the beginning of fermentation to the end of baking in maize starch bread. During fermentation, only hexanal, hexanoic acid, benzaldehyde, benzyl alcohol, furfural and furfuryl alcohol remained constant whereas the rest became more abundant. After baking, 2,3-butanedione, 1-propanol, 2-methyl-1-propanol, 3/2-methyl-1-butanol and ethyl octanoate were evaporated whereas the other volatile compounds increased. The alcohols from fermentation, 2,3-butanedione, acetoin, acetic acid, isobutyric acid and ethyl octanoate, were the main volatile compounds in dough; all of them were formed during fermentation. In crumb, alongside those compounds, hexanal, 1-octen-3-ol and nonanal, produced from lipid oxidation, were also important contributors.

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

    Science.gov (United States)

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

    2013-12-15

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

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

    Science.gov (United States)

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

    2012-03-26

    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.

  7. Analysis of Organic Volatile Flavor Compounds in Fermented Stinky Tofu Using SPME with Different Fiber Coatings

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2012-03-01

    Full Text Available 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.

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

    Science.gov (United States)

    Hallier, Arnaud; Prost, Carole; Serot, Thierry

    2005-09-07

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

  9. Production of volatile aroma compounds by bacterial strains isolated from different surface-ripened French cheeses.

    Science.gov (United States)

    Deetae, Pawinee; Bonnarme, Pascal; Spinnler, Henry E; Helinck, Sandra

    2007-10-01

    Twelve bacterial strains belonging to eight taxonomic groups: Brevibacterium linens, Microbacterium foliorum, Arthrobacter arilaitensis, Staphylococcus cohnii, Staphylococcus equorum, Brachybacterium sp., Proteus vulgaris and Psychrobacter sp., isolated from different surface-ripened French cheeses, were investigated for their abilities to generate volatile aroma compounds. Out of 104 volatile compounds, 54 volatile compounds (identified using dynamic headspace technique coupled with gas chromatography-mass spectrometry [GC-MS]) appeared to be produced by the different bacteria on a casamino acid medium. Four out of eight species used in this study: B. linens, M. foliorum, P. vulgaris and Psychrobacter sp. showed a high flavouring potential. Among these four bacterial species, P. vulgaris had the greatest capacity to produce not only the widest varieties but also the highest quantities of volatile compounds having low olfactive thresholds such as sulphur compounds. Branched aldehydes, alcohols and esters were produced in large amounts by P. vulgaris and Psychrobacter sp. showing their capacity to breakdown the branched amino acids. This investigation shows that some common but rarely mentioned bacteria present on the surface of ripened cheeses could play a major role in cheese flavour formation and could be used to produce cheese flavours.

  10. VOLATILE COMPOUNDS IDENTIFIED IN BARBADOS CHERRY ‘BRS-366 JABURÚ’

    Directory of Open Access Journals (Sweden)

    Y. M. Garcia

    2016-07-01

    Full Text Available In foods, the flavor and aroma are very important attributes, thus the main objective of this study was to identify the volatile compounds (VC of the "BRS-366 Jaburú" acerola variety, for which we used the solid phase microextraction method (SPE. The separation and identification of volatile compounds was made using gas chromatography-mass spectrometry (GC-MS. Three fibers were evaluated, Polydimethylsiloxane / Divinylbenzene (PDMS / DVB, 65 micrometres Divinylbenzene / Carboxen / Polydimethylsiloxane (DVB / CAR / PDMS 50/30 m and polyacrylate (PA 85 uM to compare the extraction of its components. Thirty-three volatile compounds were identified and classified into eight chemical classes: carboxylic acids, alcohols, aldehydes, ketones, esters, hydrocarbons, phenylpropanoids and terpenoids. The peak areas of each of the extracted compounds were expressed as percentages to indicate the relative concentration of each, of which ethyl acetate is distinguished by being responsible for the fruity aroma notes. Thus, the fiber PDMS / DVB was the best as it enabled to extract a greater amount of volatile compounds

  11. [Influence of exogenous sulfur-containing compounds on the exchange fluxes of volatile organic sulfur compounds].

    Science.gov (United States)

    Yi, Zhi-Gang; Wang, Xin-Ming

    2011-08-01

    The influences of cysteine, sodium sulfide (Na2S) and sodium sulfate (Na2SO4) on the soil-air exchange fluxes of volatile organic sulfur compounds (VOSCs), including carbonyl sulfide (COS), dimethyl sulfide (DMS), carbon disulfide (CS2) and dimethyl disulfide (DMDS), were studied employing static chamber enclosure followed by laboratory determination using an Entech 7100 preconcentrator coupled with an Agilent 5973 GC-MSD. The results showed that after the addition of cysteine, the soil for the exchange fluxes of COS and CS2 shifted to be the source from sink and the emissions of DMS and DMDS increased significant. The emission amount of DMS and CS2 accounted for 89.2% to the total VOSCs after the addition of cysteine, implying that cysteine is an important precursor for DMS and CS2 in the soil. The amount of DMDS accounted for 93.2% to the total sulfur from the soil after addition of Na2S, indicating that Na2S is a key precursor for DMDS. No significant difference of VOSCs fluxes was found between the controlled soil and the soil with addition of Na2SO4, suggesting Na2SO4 was not the direct precursor for VOSCs in soil. VOSCs exchange rates reached the maximum at 6 to 8 days after addition of cysteine. As for addition of Na2S, the maximal emission rates of different VOSCs appeared at different dates, and the dates differed significantly from those after addition of cysteine, implying that the formation process of VOSCs from the soil with addition of Na2S was more complex and different from the soil with addition of cysteine.

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

    Science.gov (United States)

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

    2009-01-01

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

  13. Characterization of Volatile Organic Compound Profiles of Bacterial Threat Agents

    Science.gov (United States)

    2008-12-01

    compounds contained in the headspace of bacterial cultures (Aathithan et al., 2001, Bunge et al., 2008, Casalinuovo et al., 2006, Lechner et al...Clin. Micro. 39: 2590-2593. Bunge M, Araghipour N, Mikoviny T, Dunkl J, Schnitzhofer R, Hansel A, Schinner F, Wisthaler A, Margesin R, and Mark T

  14. Dynamic Solution Injection: a new method for preparing pptv–ppbv standard atmospheres of volatile organic compounds

    Directory of Open Access Journals (Sweden)

    L. Abrell

    2010-11-01

    Full Text Available Proton Transfer Reaction-Mass Spectrometry (PTR-MS and thermal desorption Gas Chromatography-Mass Spectrometry (GC-MS allow for absolute quantification of a wide range of atmospheric volatile organic compounds (VOCs with concentrations in the ppbv to pptv range. Although often neglected, routine calibration is necessary for accurate quantification of VOCs by PTR-MS and GC-MS. Several gas calibration methods currently exist, including compressed gas cylinders, permeation tubes, diffusion tubes, and liquid injection. While each method has its advantages and limitations, no single technique has emerged that is capable of dynamically generating known concentrations of complex mixtures of VOCs over a large concentration range (ppbv to pptv and is technically simple, field portable, and affordable. We present the development of a new VOC calibration technique based on liquid injection with these features termed Dynamic Solution Injection (DSI. This method consists of injecting VOCs (0.1–0.5 mM dissolved in cyclohexane (PTR-MS or methanol (GC-MS into a 1.0 slpm flow of purified dilution gas in an unheated 25 ml glass vial. Upon changes in the injection flow rate (0.5–4.0 μl min−1, new VOC concentrations are reached within seconds to minutes, depending on the compound, with a liquid injection flow rate accuracy and precision of better than 7% and 4% respectively. We demonstrate the utility of the DSI technique by calibrating a PTR-MS to seven different cyclohexane solutions containing a total of 34 different biogenic compounds including volatile isoprenoids, oxygenated VOCs, fatty acid oxidation products, aromatics, and dimethyl sulfide. We conclude that because of its small size, low cost, and simplicity, the Dynamic Solution Injection method will be of great use to both laboratory and field VOC studies.

  15. Comparative Study of Volatile Compounds from Genus Ocimum

    Directory of Open Access Journals (Sweden)

    S. R. Vani

    2009-01-01

    Full Text Available There are distinct varieties of basil types in the genus Ocimum which makes them very special. Genus Ocimum is widespread over Asia, Africa and Central & Southern America. All basils are member of the Lamiaceae family. The colors of the leaves vary from bright green to purple-green and sometimes almost black. Fresh basil leaves have a strong and characteristic aroma, not comparable to any other spice, although there is a hint of clove traceable. Ocimum Sanctum, also addressed as Ocimum Tenuiflorum is a sacred plant in the Hindu culture and known as Tulasi in Tamil or Holy Basil in English. Meanwhile Ocimum Basilicum, known as Common or Sweet Basil has very dark green leaves. The genus Ocimum is cultivated for its remarkable essential oil which exhibits many usages such as in medicinal application, herbs, culinary, perfume for herbal toiletries, aromatherapy treatment and as flavoring agent. Due to varying essential oil profiles even within the same species, plants may often be classified as a different species as a result of different scents. In the present study, volatile constituents of Ocimum Sanctum and Ocimum Basilicum were extracted using various solvents and their chemical constituents were identified and quantified by using GC-MS in optimized conditions. The profiles of extract from both species were compared in an effort to investigate effects of seasonal variation on their chemical compositions. The predominant species in Ocimum Sanctum and Ocimum Basilicum was found to be methyl eugenol and methyl chavicol, respectively, during different months of analysis.

  16. Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

    Directory of Open Access Journals (Sweden)

    E. S. Cross

    2013-08-01

    Full Text Available A detailed understanding of the climate and air quality impacts of aviation requires measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs from aircraft. Currently both the amount and chemical composition of aircraft I/SVOC emissions remain poorly characterized. Here we characterize I/SVOC emissions from aircraft, using a novel instrument for the online, quantitative measurement of the mass loading and composition of low-volatility organic vapors. Emissions from the NASA DC8 aircraft were sampled on the ground 143 m downwind of the engines and characterized as a function of engine power from idle (4% maximum rated thrust through 85% power. Results show that I/SVOC emissions are highest during engine idle operating conditions, with decreasing but non-zero I/SVOC emissions at higher engine powers. Comparison of I/SVOC emissions with total hydrocarbon (THC measurements, VOC measurements, and an established emissions profile indicates that I/SVOCs comprise 10–20% of the total organic gas-phase emissions at idle, and an increasing fraction of the total gas-phase organic emissions at higher powers. Positive matrix factorization of online mass spectra is used to identify three distinct types of I/SVOC emissions: aliphatic, aromatic and oxygenated. The volatility and chemical composition of the emissions suggest that unburned fuel is the dominant source of I/SVOCs at idle, while pyrolysis products make up an increasing fraction of the I/SVOCs at higher powers. Oxygenated I/SVOC emissions were detected at lower engine powers (≤30% and may be linked to cracked, partially oxidized or unburned fuel components.

  17. Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

    Directory of Open Access Journals (Sweden)

    E. S. Cross

    2013-03-01

    Full Text Available A detailed understanding of the climate and air quality impacts of aviation requires detailed measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs from aircraft. Currently both the amount and chemical composition of aircraft I/SVOC emissions remain poorly characterized. Here we characterize I/SVOC emissions from aircraft, using a novel instrument for the online, quantitative measurement of the mass loading and composition of low-volatility organic vapors. Emissions from the NASA DC8 aircraft were sampled on the ground, 143 m downwind of the engines and characterized as a function of engine power from ground idle (~4% maximum rated thrust through 85% power. Results show that I/SVOC emissions are highest during engine-idle operating conditions, with decreasing but non-zero I/SVOC emissions at higher engine powers. Comparison of I/SVOC emissions with total hydrocarbon (THC measurements, VOC measurements, and an established emissions profile indicates that I/SVOCs comprise 10–20% of the total organic gas phase emissions at idle, and an increasing fraction of the total gas phase organic emissions at higher powers. Positive matrix factorization of online mass spectra is used to identify three distinct types of I/SVOC emissions: aliphatic, aromatic and oxygenated. The volatility and chemical composition of the emissions suggest that unburned fuel is the dominant source of I/SVOCs at idle, while pyrolysis products make up an increasing fraction of the I/SVOCs at higher powers. Oxygenated I/SVOC emissions were detected at lower engine powers (≤30% and may be linked to cracked, partially oxidized or unburned fuel components.

  18. Recovery of volatile aroma compounds from black currant juice by vacuum membrane distillation

    DEFF Research Database (Denmark)

    Bagger-Jørgensen, Rico; Meyer, Anne S.; Warming, C.

    2004-01-01

    l/h at 30 degreesC gave concentration factors, calculated for each aroma compound as C-permeate/C-feed: from similar to4 to 15. The concentration factors increased with decreased juice temperature during VMD; at 10 degreesC concentration factors of 21-31 were obtained for the highly volatile aroma....... VMD thus turned out to be a promising technique for gentle stripping of black currant juice aroma compounds....

  19. Volatile Compounds of New Promising Dried Apricot (Prunus armeniaca L. Genotypes

    Directory of Open Access Journals (Sweden)

    Burhanettin IMRAK

    2016-12-01

    Full Text Available Turkey has rich wild apricot populations and all Turkish apricot cultivars were previously selected among wild apricots. On this background for apricot breeding, six new late flowering dried apricot genotypes were taken under study, along with wide spread cv. ‘Hacihaliloglu’; all genotypes were examined in terms of volatile compounds using Headspace-Solid Phase Micro Extraction - Mass Spectrometry (HSSPME/GC/MS techniques. The most important volatiles of apricot genotypes were aldehydes, alcohols, esters, terpenes, ketones and acids. Among these compounds, ethanol, hexanal, 3-carene, squalene, acetic acid, tetradecaonic acid, pentadecaonic acid, octadecaonic acid, n- hexadecaonic acid and 1-hdroxy-2-propanone were present in all genotypes studied at certain levels. In general, total concentrations of aroma compounds were higher in some promising genotypes under study than within ‘Hacihaliloglu’ cultivar, except total alcohol compound (53.33%. Volatile compounds, particularly esters, were the major contributors to fruity, floral and pleasant fruit flavours. The highest esters’ compound contents were detected in ‘N95’ (9.2% and ‘N57’ (2.18% genotypes, while ‘Hacihaliloglu’ had 1.61% ester compounds. Lacton (γ-decalactone was a key aroma compound of apricot. γ-decalactone was detected ranging between 0.4-1.13% in all genotypes, except cv. ‘Hacihaliloglu’. The hereby obtained results showed that the volatile composition depended largely upon the apricot genotypes, moment of harvest, growing conditions and cultural applications that may all affect fruit quality. These results represent valuable starting points for apricot breeding programs.

  20. Bioactive and volatile organic compounds in Southern Brazilian blackberry (Rubus Fruticosus) fruit cv. Tupy

    OpenAIRE

    Andressa Carolina Jacques; Fábio Clasen Chaves; Rui Carlos Zambiazi; Márcia Campos Brasil; Elina Bastos Caramão

    2014-01-01

    Blackberry (Rubus fruticosus, cultivar Tupy), an expanding fruit crop in southern Brazil, is greatly appreciated for its flavor and bioactive potential with limited characterization of its metabolite content. The purpose of this study was to characterize the bioactive and volatile organic compound (VOC) content of mature blackberry fruit of cultivar Tupy. Gallic acid, (-)-epicatechin, ferulic acid, and quercetin were the main phenolic compounds found in mature fruit. Among the VOCs identified...

  1. 40 CFR 60.502 - Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals.

    Science.gov (United States)

    2010-07-01

    ... (VOC) emissions from bulk gasoline terminals. 60.502 Section 60.502 Protection of Environment... SOURCES Standards of Performance for Bulk Gasoline Terminals § 60.502 Standard for Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. On and after the date on which § 60.8(a) requires a...

  2. Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air

    NARCIS (Netherlands)

    Scholten, E.; Bromberg, L.; Rutledge, G.C.; Hatton, T.A.

    2011-01-01

    Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2014-05-15

    Gas chromatography with mass spectrometric detection (GC-MS) coupled with solid phase micro-extraction as pre-concentration method (SPME) was applied to identify and quantify volatile organic compounds (VOCs) emitted by human skin. A total of 64 C4-C10 compounds were quantified in skin emanation of 31 healthy volunteers. Amongst them aldehydes and hydrocarbons were the predominant chemical families with eighteen and seventeen species, respectively. Apart from these, there were eight ketones, six heterocyclic compounds, six terpenes, four esters, two alcohols, two volatile sulphur compounds, and one nitrile. The observed median emission rates ranged from 0.55 to 4,790 fmol cm(-2)min(-1). Within this set of analytes three volatiles; acetone, 6-methyl-5-hepten-2-one, and acetaldehyde exhibited especially high emission rates exceeding 100 fmol cm(-2)min(-1). Thirty-three volatiles were highly present in skin emanation with incidence rates over 80%. These species can be considered as potential markers of human presence, which could be used for early location of entrapped victims during Urban Search and Rescue Operations (USaR).

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

  8. Can ornamental potted plants remove volatile organic compounds from indoor air? - a review

    DEFF Research Database (Denmark)

    Dela Cruz, Majbrit; Christensen, Jan H.; Thomsen, Jane Dyrhauge;

    2014-01-01

    Volatile organic compounds (VOCs) are found in indoor air, and many of these can affect human health (e.g. formaldehyde and benzene are carcinogenic). Plants affect the levels of VOCs in indoor environments, thus they represent a potential green solution for improving indoor air quality...

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    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...

  11. Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air

    NARCIS (Netherlands)

    Scholten, E.; Bromberg, L.; Rutledge, G.C.; Hatton, T.A.

    2011-01-01

    Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and tetrame

  12. 77 FR 14324 - National Volatile Organic Compound Emission Standards for Aerosol Coatings-Addition of Dimethyl...

    Science.gov (United States)

    2012-03-09

    .... Email: a-and-r-docket@epa.gov . Fax: (202) 566-9744. Mail: U.S. Postal Service, send comments to: EPA... Factors AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: The EPA is proposing to amend the National Volatile Organic Compound Emission Standards for Aerosol Coatings final rule...

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

    Science.gov (United States)

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

  14. Removal of H2S and volatile organic sulfur compounds by silicone membrane extraction

    NARCIS (Netherlands)

    Manconi, I.; Lens, P.N.L.

    2009-01-01

    BACKGROUND: This study explores an alternative process for the abatement and/or desulfurization of H2S and volatile organic sulfur compounds (VOSC) containing waste streams, which employs a silicone-based membrane to simultaneously remove H2S and VOSC. An extractive membrane reactor allows the selec

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

    Science.gov (United States)

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

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

    NARCIS (Netherlands)

    Kesselmeier, J.; Ciccioli, P.; Kuhn, U.; Stefani, P.; Biesenthal, T.; Rottenberger, S.; Wolf, A.; Vitullo, M.; Valentini, R.; Nobre, A.; Kabat, P.; Andreae, M.O.

    2002-01-01

    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

  17. Removal of volatile organic compounds in vertical flow filters: predictions from Reactive Transport Modeling

    NARCIS (Netherlands)

    De Biase, C.; Maier, U.; Baeder-Bederski, O.; Bayer, P.; Oswald, S.E.; Thullner, M.

    2011-01-01

    Vertical flow filters are containers filled with porous medium that are recharged from top and drained at the bottom, and are operated at partly saturated conditions. They have recently been suggested as treatment technology for groundwater containing volatile organic compounds (VOCs). Numerical rea

  18. Removal of volatile organic compounds in vertical flow filters: predictions from Reactive Transport Modeling

    NARCIS (Netherlands)

    De Biase, C.; Maier, U.; Baeder-Bederski, O.; Bayer, P.; Oswald, S.E.; Thullner, M.

    2011-01-01

    Vertical flow filters are containers filled with porous medium that are recharged from top and drained at the bottom, and are operated at partly saturated conditions. They have recently been suggested as treatment technology for groundwater containing volatile organic compounds (VOCs). Numerical rea

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

    DEFF Research Database (Denmark)

    Kostesha, Natalie; Alstrøm, Tommy Sonne; Johnsen, C

    2010-01-01

    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...

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    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...

  2. Detection of diseased plants by analysis of volatile organic compound emission

    NARCIS (Netherlands)

    Jansen, R.M.C.; Wildt, J.; Kappers, I.F.; Bouwmeester, H.J.; Hofstee, J.W.; Henten, van E.

    2011-01-01

    This review focuses on the detection of diseased plants by analysis of volatile organic compound (VOC) emissions. It includes an overview of studies that report on the impact of infectious and noninfectious diseases on these emissions and discusses the specificity of disease-induced emissions. The

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

    Science.gov (United States)

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

  4. Changes in volatile compounds in whey protein concentrate stored at elevated temperature and humidity

    Science.gov (United States)

    Whey protein concentrate (WPC) has been recommended for use in emergency aid programs, but it is often stored overseas without temperature and relative humidity (RH) control, which may cause it to be rejected because of yellowing, off-flavors, or clumping. Therefore, the volatile compounds present ...

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

    Science.gov (United States)

    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...

  6. Removal of volatile organic compounds in vertical flow filters: predictions from Reactive Transport Modeling

    NARCIS (Netherlands)

    De Biase, C.; Maier, U.; Baeder-Bederski, O.; Bayer, P.; Oswald, S.E.; Thullner, M.

    2011-01-01

    Vertical flow filters are containers filled with porous medium that are recharged from top and drained at the bottom, and are operated at partly saturated conditions. They have recently been suggested as treatment technology for groundwater containing volatile organic compounds (VOCs). Numerical

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

    Science.gov (United States)

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

    2015-02-01

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

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

    NARCIS (Netherlands)

    Lykomitros, Dimitrios; Fogliano, Vincenzo; Capuano, Edoardo

    2016-01-01

    Flavor and color of roasted peanuts are important research areas due to their significant influence on consumer preference. The aim of the present study was to explore correlations between sensory attributes of peanuts, volatile headspace compounds and color parameters. Different raw peanuts were se

  9. Detection of diseased plants by analysis of volatile organic compound emission

    NARCIS (Netherlands)

    Jansen, R.M.C.; Wildt, J.; Kappers, I.F.; Bouwmeester, H.J.; Hofstee, J.W.; Henten, van E.

    2011-01-01

    This review focuses on the detection of diseased plants by analysis of volatile organic compound (VOC) emissions. It includes an overview of studies that report on the impact of infectious and noninfectious diseases on these emissions and discusses the specificity of disease-induced emissions. The r

  10. Analysis of selected volatile organic compounds at background level in South Africa.

    Science.gov (United States)

    Ntsasa, Napo; Tshilongo, James; Lekoto, Goitsemang

    2017-04-01

    Volatile organic compounds (VOC) are measured globally at urban air pollution monitoring and background level at specific locations such as the Cape Point station. The urban pollution monitoring is legislated at government level; however, the background levels are scientific outputs of the World Meteorological Organisation Global Atmospheric Watch program (WMO/GAW). The Cape Point is a key station in the Southern Hemisphere which monitors greenhouse gases and halocarbons, with reported for over the past decade. The Cape Point station does not have the measurement capability VOC's currently. A joint research between the Cape Point station and the National Metrology Institute of South Africa (NMISA) objective is to perform qualitative and quantitative analysis of volatile organic compounds listed in the GAW program. NMISA is responsible for development, maintain and disseminate primary reference gas mixtures which are directly traceable to the International System of Units (SI) The results of some volatile organic compounds which where sampled in high pressure gas cylinders will be presented. The analysis of samples was performed on the gas chromatography with flame ionisation detector and mass selective detector (GC-FID/MSD) with a dedicate cryogenic pre-concentrator system. Keywords: volatile organic compounds, gas chromatography, pre-concentrator

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    Kobayashi, Michiko; Shimizu, Hiroshi; Shioya, Suteaki

    2008-10-01

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

  13. Geographical provenance of palm oil by fatty acid and volatile compound fingerprinting techniques

    NARCIS (Netherlands)

    Tres, A.; Ruiz - Samblas, C.; Veer, van der G.; Ruth, van S.M.

    2013-01-01

    Analytical methods are required in addition to administrative controls to verify the geographical origin of vegetable oils such as palm oil in an objective manner. In this study the application of fatty acid and volatile organic compound fingerprinting in combination with chemometrics have been appl

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

    Science.gov (United States)

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

  15. Volatile organic compound emmission rates from mixed deciduous and coniferous foest in Northern Wisconsin, USA

    Science.gov (United States)

    J. G. Isebrands; A. B. Guenther; P. Harley; D. Helmig; L. Klinger; L. Vierling; P. Zimmerman; C. Geron

    1999-01-01

    Biogenic emissions of volatile organic compounds {VOC) from forests play an important role in regulating the atmospheric trace gas composition including global tropospheric ozone concentrations. However, more information is needed on VOC emission rates from different forest regions of the world to understand regional and global impacts and to implement possible...

  16. Infrared decontamination of oregano: effects on Bacillus cereus spores, water activity, color, and volatile compounds.

    Science.gov (United States)

    Eliasson, Lovisa; Libander, Patrik; Lövenklev, Maria; Isaksson, Sven; Ahrné, Lilia

    2014-12-01

    Infrared (IR) heating, a novel technology for decontaminating oregano, was evaluated by investigating the reduction of inoculated Bacillus cereus spores and the effect on water activity (a(w)), color, and headspace volatile compounds after exposure to IR treatment. Conditioned oregano (a(w) 0.88) was IR-treated in a closed heating unit at 90 and 100 °C for holding times of 2 and 10 min, respectively. The most successful reduction in B. cereus spore numbers (5.6 log units) was achieved after a holding time of 10 min at 90 °C, while treatment at 100 °C for the same time resulted in a lower reduction efficiency (4.7 log units). The lower reduction at 100 °C was probably due to a reduced aw (aw 0.76) during IR treatment or possibly to the alteration or loss of volatile compounds possessing antimicrobial properties. The green color of oregano was only slightly affected, while the composition of volatile compounds was clearly altered by IR heating. However, two of the key aroma compounds, carvacrol and thymol, were only slightly affected, compared to the effect on the other studied compounds, indicating that the typical oregano aroma can likely be preserved. In conclusion, IR heating shows potential for the successful decontamination of oregano without severe alteration of its color or the key aroma compounds, carvacrol and thymol.

  17. Ionic Liquids in the Synthesis of Antioxidant Targeted Compounds

    NARCIS (Netherlands)

    Falkeborg, Mia; Berton-Carabin, Claire C.; Cheong, Ling Zhi

    2016-01-01

    Oxidation of polyunsaturated lipids is a major cause of degradation of the sensory and nutritional quality of food products. The oxidation reactions lead to formation of volatile compounds generally associated with unpleasant flavors, which damages the sensory quality of foods. Lipid oxidation is

  18. Ionic Liquids in the Synthesis of Antioxidant Targeted Compounds

    NARCIS (Netherlands)

    Falkeborg, Mia; Berton-Carabin, Claire C.; Cheong, Ling Zhi

    2016-01-01

    Oxidation of polyunsaturated lipids is a major cause of degradation of the sensory and nutritional quality of food products. The oxidation reactions lead to formation of volatile compounds generally associated with unpleasant flavors, which damages the sensory quality of foods. Lipid oxidation is

  19. Development of a direct exposure system for studying the mechanisms of central neurotoxicity caused by volatile organic compounds.

    Science.gov (United States)

    Kanemitsu, Masanari; Fueta, Yukiko; Ishidao, Toru; Aou, Shuji; Hori, Hajime

    2016-01-01

    Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a constant bath concentration of relatively highly volatile solvents, e.g. 1-bromopropane (1-BP). Here we report a new exposure system for VOCs that we developed in which a high concentration of oxygen is dissolved to a perfused medium applying a gas-liquid equilibrium, and in which the tubing is made of Teflon, non adsorptive material. Using our system, the bath concentration of the perfused 1-BP remained stable for at least 2 h in the slice chamber. Both 6.4 and 2.2 mM of 1-BP did not change the paired-pulse response, but fully suppressed long-term potentiation in the dentate gyrus (DG) of hippocampal slices obtained from rats, suggesting that 1-BP decreases synaptic plasticity in the DG at the concentrations tested. Our new system can be applicable for investigating the underlying mechanisms of the neurotoxicity of VOCs at the cellular level.

  20. Development of a direct exposure system for studying the mechanisms of central neurotoxicity caused by volatile organic compounds

    Science.gov (United States)

    KANEMITSU, Masanari; FUETA, Yukiko; ISHIDAO, Toru; AOU, Shuji; HORI, Hajime

    2015-01-01

    Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a constant bath concentration of relatively highly volatile solvents, e.g. 1-bromopropane (1-BP). Here we report a new exposure system for VOCs that we developed in which a high concentration of oxygen is dissolved to a perfused medium applying a gas-liquid equilibrium, and in which the tubing is made of Teflon, non adsorptive material. Using our system, the bath concentration of the perfused 1-BP remained stable for at least 2 h in the slice chamber. Both 6.4 and 2.2 mM of 1-BP did not change the paired-pulse response, but fully suppressed long-term potentiation in the dentate gyrus (DG) of hippocampal slices obtained from rats, suggesting that 1-BP decreases synaptic plasticity in the DG at the concentrations tested. Our new system can be applicable for investigating the underlying mechanisms of the neurotoxicity of VOCs at the cellular level. PMID:26320726

  1. Attraction of the gypsy moth to volatile organic compounds (VOCs) of damaged Dahurian larch.

    Science.gov (United States)

    Li, Jing; Valimaki, Sanna; Shi, Juan; Zong, Shixiang; Luo, Youqing; Heliovaara, Kari

    2012-01-01

    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.

  2. Involvement of a broccoli COQ5 methyltransferase in the production of volatile selenium compounds.

    Science.gov (United States)

    Zhou, Xin; Yuan, Youxi; Yang, Yong; Rutzke, Michael; Thannhauser, Theodore W; Kochian, Leon V; Li, Li

    2009-10-01

    Selenium (Se) is an essential micronutrient for animals and humans but becomes toxic at high dosage. Biologically based Se volatilization, which converts Se into volatile compounds, provides an important means for cleanup of Se-polluted environments. To identify novel genes whose products are involved in Se volatilization from plants, a broccoli (Brassica oleracea var italica) cDNA encoding COQ5 methyltransferase (BoCOQ5-2) in the ubiquinone biosynthetic pathway was isolated. Its function was authenticated by complementing a yeast coq5 mutant and by detecting increased cellular ubiquinone levels in the BoCOQ5-2-transformed bacteria. BoCOQ5-2 was found to promote Se volatilization in both bacteria and transgenic Arabidopsis (Arabidopsis thaliana) plants. Bacteria expressing BoCOQ5-2 produced an over 160-fold increase in volatile Se compounds when they were exposed to selenate. Consequently, the BoCOQ5-2-transformed bacteria had dramatically enhanced tolerance to selenate and a reduced level of Se accumulation. Transgenic Arabidopsis expressing BoCOQ5-2 volatilized three times more Se than the vector-only control plants when treated with selenite and exhibited an increased tolerance to Se. In addition, the BoCOQ5-2 transgenic plants suppressed the generation of reactive oxygen species induced by selenite. BoCOQ5-2 represents, to our knowledge, the first plant enzyme that is not known to be directly involved in sulfur/Se metabolism yet was found to mediate Se volatilization. This discovery opens up new prospects regarding our understanding of the complete metabolism of Se and may lead to ways to modify Se-accumulator plants with increased efficiency for phytoremediation of Se-contaminated environments.

  3. Distribution of volatile organic compounds in Madrid (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Pastor, R.M.; Garcia-Alonso, S.; Quejido Cabezas, A.J. [CIEMAT, Madrid (Spain)

    1999-07-01

    From November 1995 to October 1996, airborne concentrations of VOCs were measured in the Madrid area to study the organic pollution in general, and the correlation between different pollutants in relation to such parameters as location and season. Mean concentrations for up to 90 compounds were measured at four test sites, including both urban and suburban areas. At the urban sites, maximum concentrations occurred in the autumn and winter, whereas minimum concentrations were reached in summer and spring. Similar changes were obtained for the less-contaminated site located in the SE of the city, whereas a different pattern was found at the site in the NW of the city due to meteorological aspects. Mean levels of hydrocarbons in Madrid were quite similar to those found in other European cities. Chemometrical techniques were applied to the set of data in order to assess the influence of such factors as traffic, temperature and seasonal variations on the VOC levels. (orig.)

  4. Maximizing Information from Residential Measurements of Volatile Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Li, Na [Berkeley Analytical Associates, Richmond, CA (United States); Hodgson, Alfred [Berkeley Analytical Associates, Richmond, CA (United States); Offermann, Francis [Indoor Environmental Engineering, San Francisco, CA (United States); Singer, Brett [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-02-01

    Continually changing materials used in home construction and finishing can introduce new chemicals or changes in the VOC profile in residential air and the trend towards tighter homes can lead to higher exposure concentrations for many indoor sources. However, the complex mixture of VOCs in residential air makes it difficult to discover emerging contaminants and/or trends in pollutant profiles. The purpose of this study is to prepare a comprehensive library of chemicals found in homes, along with a semi-quantitative approach to maximize the information gained from VOC measurements. We carefully reviewed data from 108 new California homes and identified 238 individual compounds. The majority of the identified VOCs originated indoors. Only 31% were found to have relevant health based exposure guidelines and less than 10% had a chronic reference exposure level (CREL). The finding highlights the importance of extending IAQ studies to include a wider range of VOCs

  5. Exposure to Volatile Organic Compounds and Possibility of Exposure to By-product Volatile Organic Compounds in Photolithography Processes in Semiconductor Manufacturing Factories.

    Science.gov (United States)

    Park, Seung-Hyun; Shin, Jung-Ah; Park, Hyun-Hee; Yi, Gwang Yong; Chung, Kwang-Jae; Park, Hae-Dong; Kim, Kab-Bae; Lee, In-Seop

    2011-09-01

    The purpose of this study was to measure the concentration of volatile organic compound (VOC)s originated from the chemicals used and/or derived from the original parental chemicals in the photolithography processes of semiconductor manufacturing factories. A total of four photolithography processes in 4 Fabs at three different semiconductor manufacturing factories in Korea were selected for this study. This study investigated the types of chemicals used and generated during the photolithography process of each Fab, and the concentration levels of VOCs for each Fab. A variety of organic compounds such as ketone, alcohol, and acetate compounds as well as aromatic compounds were used as solvents and developing agents in the processes. Also, the generation of by-products, such as toluene and phenol, was identified through a thermal decomposition experiment performed on a photoresist. The VOC concentration levels in the processes were lower than 5% of the threshold limit value (TLV)s. However, the air contaminated with chemical substances generated during the processes was re-circulated through the ventilation system, thereby affecting the airborne VOC concentrations in the photolithography processes. Tens of organic compounds were being used in the photolithography processes, though the types of chemical used varied with the factory. Also, by-products, such as aromatic compounds, could be generated during photoresist patterning by exposure to light. Although the airborne VOC concentrations resulting from the processes were lower than 5% of the TLVs, employees still could be exposed directly or indirectly to various types of VOCs.

  6. Volatile compounds of healthy and insect-damaged Hippophae rhamnoides sinensis in natural and planted forests.

    Science.gov (United States)

    Zong, Shixiang; Luo, Youqing; Zhou, Jiao; Liu, Shujing

    2012-01-01

    Volatile compounds of healthy and insect-damaged stems of Hippophae rhamnoides sinensis were analysed using dynamic headspace and thermal-desorption cold-trap injector gas chromatography/mass spectroscopy (TCT-GC/MS). Sixteen compounds, belonging to alkanes, alcohols, aldehydes, esters, ketones, and ethers, were identified in the stems of healthy H. rhamnoides sinensis; the compounds in H. rhamnoides sinensis occurring naturally or cultivated in plantations were similar, but the relative contents were significantly different. In plants damaged by Holcocerus hippophaecolus, the nature and content of the volatile compounds were greatly changed. Butanedione and butyl glyoxylate were newly generated after damage by the pest, and the relative levels of pentanal, heptanal, eucalyptol, terpineol, and camphor were sharply increased in both naturally occurring and plantation-grown plants. n-Decane, trans-2-nonen-1-ol, and n-hexadecane levels increased in plants cultivated in the plantation and decreased in natural forests, whereas the levels of other types were reduced. Thus, both the nature and the content of volatile compounds of H. rhamnoides sinensis are affected by H. hippophaecolus damage, providing a theoretical basis to identify the mechanism of pest destruction.

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

    Directory of Open Access Journals (Sweden)

    Ludmilla Lumholdt

    2014-11-01

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

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

    Science.gov (United States)

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

    2017-09-09

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

  9. Free amino acids and other non-volatile compounds formed during processing of Iberian ham.

    Science.gov (United States)

    Martín, L; Antequera, T; Ventanas, J; Benítez-Donoso, R; Córdoba, J J

    2001-12-01

    Fifty-five legs from Iberian pigs were traditionally processed into dry cured hams. Free amino acids and other non-volatile compounds in the water-soluble fraction from the biceps femoris muscle were analyzed by HPLC. At the drying stage and in the last months in the cellar the largest increases in these water-soluble compounds took place. There was a clear influence on free amino acid formation of salt content and on the formation of peptides of the temperature at each processing stage. As the amount of non-volatile compounds in the water-soluble fraction increases with processing time, their determination could provide a maturation index for Iberian ham.

  10. Production of volatile and sulfur compounds by ten Saccharomyces cerevisiae strains inoculated in Trebbiano must

    Directory of Open Access Journals (Sweden)

    Francesca ePatrignani

    2016-03-01

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

  11. Comparison of SPME Methods for Determining Volatile Compounds in Milk, Cheese, and Whey Powder

    Directory of Open Access Journals (Sweden)

    Michael H. Tunick

    2013-11-01

    Full Text Available Solid phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but conditions have to be adjusted to maximize release while not generating new compounds that are absent in the original sample. Queso Fresco, a fresh non-melting cheese, may be heated at 60 °C for 30 min; in contrast, compounds are produced in milk when exposed to light and elevated temperatures, so milk samples are heated as little as possible. Products such as dehydrated whey protein are more stable and can be exposed to longer periods (60 min of warming at lower temperature (40 °C without decomposition, allowing for capture and analysis of many minor components. The techniques for determining the volatiles in dairy products by SPME and GC-MS have to be optimized to produce reliable results with minimal modifications and analysis times.

  12. Volatile Compounds in Dry Dog Foods and Their Influence on Sensory Aromatic Profile

    Directory of Open Access Journals (Sweden)

    Koushik Adhikari

    2013-02-01

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

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

    Science.gov (United States)

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

    2013-02-27

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

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

    Science.gov (United States)

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

    2008-06-09

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

  15. Volatile organic compounds in the air of Izmir, Turkey

    Science.gov (United States)

    Muezzinoglu, Aysen; Odabasi, Mustafa; Onat, Levent

    A sampling program was conducted to determine the ambient VOC levels in the city of Izmir, Turkey during daytime and overnight periods between mid-August and mid-September 1998. Sampling sites were selected at high-density traffic roads and junctions far from stationary VOC sources. Samples were analyzed for benzene, toluene, m, p-xylene and o-xylene (BTX), alkylbenzenes (ethylbenzene, 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene), n-hexane and, n-heptane. Results were compared with similar data from other cities around the world and for probable health dangers and sources of the compounds. Results of this study indicated that Izmir has rather high ambient BTX concentrations compared to many polluted cities in the world. Toluene was the most abundant VOC in Izmir air and was followed by xylenes, benzene and alkylbenzenes, respectively. All were strongly dependent on the expected daily variations of traffic flow in the city. The concentrations of other VOCs correlated well with benzene concentration at most sampling sites, excluding Gumuldur station indicating that ambient VOC levels were mainly affected by motor vehicle emissions. The toluene-to-benzene ratios for urban and non-urban sites were in good agreement with previously reported values, indicating a good relationship between the motor vehicle emissions and ambient VOC levels.

  16. Determination of volatile compounds in Grenache wines in relation with different terroirs in the Rhone Valley.

    Science.gov (United States)

    Sabon, Isabelle; De Revel, Gilles; Kotseridis, Yorgos; Bertrand, Alain

    2002-10-23

    This paper describes the study of 19 wines of the Grenache Noir cultivar obtained from representative soils of the Rhone Valley according to their geographical site, climatic conditions, hydrological regulation, and soil profile. Among the volatile compounds analyzed by GC/MS/FID, the concentrations of the varietal compounds (i.e., beta-damascenone, beta-ionone, and geraniol) and those of the compounds without direct influence on the wine aroma (i.e., hexenols and methanol) indicated the existence of two groups of wines. These concentrations were correlated with grape maturity due to the ecosystem and particularly the soil.

  17. New UPLC coupled to mass spectrometry approaches for screening of non-volatile compounds as potential migrants from adhesives used in food packaging materials.

    Science.gov (United States)

    Canellas, E; Nerín, C; Moore, R; Silcock, P

    2010-05-07

    The objective of this study was to identify the non-volatile compounds as potential migrants from adhesives used in food packaging. A number of the current acrylic adhesive formulations were extracted and prepared for analysis. The extracts were screened using ultra-performance liquid chromatography coupled to a time-of-flight mass spectrometer detector (UPLC-TOF-MS). This approach allowed the identification of several components by a combination of exact mass and in-source collision induced dissociation (CID). Due to the lack of freely available information on adhesive formulations further analyses were undertaken using ultra-performance liquid chromatography coupled to high definition mass spectrometry (UPLC-HDMS). Using the Mass Fragment tool to interrogate fragmentation data, a wide series of compounds were identified, demonstrating the usefulness and importance of these tools for difficult problems. Moreover, using several packaging materials containing adhesives, qualitative migration tests were performed with Tenax as a food simulant. Several non-volatile compounds were identified as well in the Tenax which emphasizes the importance of this work and demonstrates that even the non-volatile compounds have the potential to migrate into food which is in contact with packaging materials. The main characteristics of the screening study and the results obtained are shown and discussed.

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

    Science.gov (United States)

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

    2015-10-15

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

  19. Volatile aromatic compounds in Mexico City atmosphere: levels and source apportionment

    Energy Technology Data Exchange (ETDEWEB)

    Mugica, V. [Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D.F. (Mexico); Ruiz, M.E. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Watson, J.; Chow, J. [Desert Research Institute, Reno, Nevada (United States)

    2003-01-01

    Samples of ambient air were simultaneously collected at three different sites of Mexico City in March of 1997 in order to quantify the most abundant volatile aromatic compounds and estimate the source contributions by application of the chemical mass balance model (CMB). Volatile aromatic compounds were around 20% of the total of non-methane hydrocarbons present in morning air samples. The most abundant volatile aromatic species in urban air were toluene and xylenes followed by 1, 2, 4 trimethylbenzene, benzene, ethylbenzene, metaethyltoluene, 1, 3, 5 trimethylbenzene, styrene, n propylbenzene, and isopropylbenzene. Sampling campaigns were carried out at crossroads, a bus station, a parking place, and areas where solvents and petroleum distillates are used, with the objective of determining people's exposure to volatile aromatic compounds. The CMB was applied for estimating the contribution of different sources to the presence of each one of the most abundant aromatic compounds. Motor vehicle exhaust was the main source of all aromatic compounds, especially gasoline exhaust, although diesel exhausts and asphalt operations also accounted for toluene, xylenes, ethylbenzene, propylbenzenes, and styrene. Graphic arts and paint applications had an important impact on the presence of toluene. [Spanish] Se colectaron simultaneamente muestras de aire ambiente en tres sitios de la Ciudad de Mexico durante el mes de marzo de 1997 con el fin de conocer las concentraciones y el origen de compuestos aromaticos utilizando el modelo de balance de masa de especies quimicas (CMB). Los compuestos aromaticos volatiles representaron alrededor del 20% del total de hidrocarburos no metalicos presentes en las muestras matutinas colectadas. Las especies aromaticas volatiles mas abundantes en el ambiente fueron el tolueno y los xilenos, seguidos por 1, 2, 4 trimetilbenceno, benceno, etilbenceno, metaetiltolueno, nporpilbenceno, isopropilbenceno, 1, 3, 5 trimetilbenceno y estireno. Se

  20. Release of bioactive volatiles from supramolecular hydrogels: influence of reversible acylhydrazone formation on gel stability and volatile compound evaporation.

    Science.gov (United States)

    Buchs, Barbara; Fieber, Wolfgang; Vigouroux-Elie, Florence; Sreenivasachary, Nampally; Lehn, Jean-Marie; Herrmann, Andreas

    2011-04-21

    In the presence of alkali metal cations, guanosine-5'-hydrazide (1) forms stable supramolecular hydrogels by selective self-assembly into a G-quartet structure. Besides being physically trapped inside the gel structure, biologically active aldehydes or ketones can also reversibly react with the free hydrazide functions at the periphery of the G-quartet to form acylhydrazones. This particularity makes the hydrogels interesting as delivery systems for the slow release of bioactive carbonyl derivatives. Hydrogels formed from 1 were found to be significantly more stable than those obtained from guanosine. Both physical inclusion of bioactive volatiles and reversible hydrazone formation could be demonstrated by indirect methods. Gel stabilities were measured by oscillating disk rheology measurements, which showed that thermodynamic equilibration of the gel is slow and requires several cooling and heating cycles. Furthermore, combining the rheology data with dynamic headspace analysis of fragrance evaporation suggested that reversible hydrazone formation of some carbonyl compounds influences the release of volatiles, whereas the absolute stability of the gel seemed to have no influence on the evaporation rates.

  1. The prey's scent - Volatile organic compound mediated interactions between soil bacteria and their protist predators.

    Science.gov (United States)

    Schulz-Bohm, Kristin; Geisen, Stefan; Wubs, E R Jasper; Song, Chunxu; de Boer, Wietse; Garbeva, Paolina

    2017-03-01

    Protists are major predators of bacteria in soils. However, it remains unknown how protists sense their prey in this highly complex environment. Here, we investigated whether volatile organic compounds (VOCs) of six phylogenetic distinct soil bacteria affect the performance of three different soil protists and how that relates to direct feeding interactions. We observed that most bacteria affected protist activity by VOCs. However, the response of protists to the VOCs was strongly dependent on both the bacterial and protist interacting partner. Stimulation of protist activity by volatiles and in direct trophic interaction assays often coincided, suggesting that VOCs serve as signals for protists to sense suitable prey. Furthermore, bacterial terpene synthase mutants lost the ability to affect protists, indicating that terpenes represent key components of VOC-mediated communication. Overall, we demonstrate that volatiles are directly involved in protist-bacterial predator-prey interactions.

  2. Experimental Study of the Influence of Operating Position on the Behavior of an Electromechanical Actuator with Volatile Liquid

    Directory of Open Access Journals (Sweden)

    NITAN Ilie

    2013-05-01

    Full Text Available This paper presents an experimental study of the influence of operating position on the behavior of an electrochemical actuator with volatile liquid. In the introduction, the operating principle of electromechanical actuators with volatile liquid is described. Are then presented experimental stand used, the study results and conclusions drawn from the studies.

  3. Simultaneous determination of six mercapturic acid metabolites of volatile organic compounds in human urine.

    Science.gov (United States)

    Ding, Yan S; Blount, Benjamin C; Valentin-Blasini, Liza; Applewhite, Heather S; Xia, Yang; Watson, Clifford H; Ashley, David L

    2009-06-01

    The widespread exposure to potentially harmful volatile organic compounds (VOCs) merits the development of practical and accurate exposure assessment methods. Measuring the urinary concentrations of VOC mercapturic acid (MA) metabolites provides noninvasive and selective information about recent exposure to certain VOCs. We developed a liquid chromatography-tandem mass spectrometry method for quantifying urinary levels of six MAs: N-acetyl-S-(2-carboxyethyl)-L-cysteine (CEMA), N-acetyl-S-(3-hydroxypropyl)-L-cysteine (HPMA), N-acetyl-S-(2-hydroxy-3-butenyl)-L-cysteine (MHBMA), N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-acetyl-S-(2-hydroxyethyl)-L-cysteine (HEMA), and N-acetyl-S-(phenyl)-L-cysteine (PMA). The method provides good accuracy (102% mean accuracy) and high precision (3.5% mean precision). The sensitivity (limits of detection of 0.01-0.20 microg/L) and wide dynamic detection range (0.025-500 microg/L) make this method suitable for assessing VOC exposure of minimally exposed populations and those with significant exposures, such as cigarette smokers. We used this method to quantify MA levels in urine collected from smokers and nonsmokers. Median levels of creatinine-corrected CEMA, HPMA, MHBMA, DHBMA, HEMA, and PMA among nonsmokers (n = 59) were 38.1, 24.3, 21.3, 104.7, 0.9, and 0.5 microg/g creatinine, respectively. Among smokers (n = 61), median levels of CEMA, HPMA, MHBMA, DHBMA, HEMA, and PMA were 214.4, 839.7, 10.2, 509.7, 2.2, and 0.9 microg/g creatinine, respectively. All VOC MAs measured were higher among smokers than among nonsmokers, with the exception of MHBMA.

  4. Core-shell nanostructured hybrid composites for volatile organic compound detection

    Directory of Open Access Journals (Sweden)

    Tung TT

    2015-08-01

    Full Text Available Tran Thanh Tung,1,2 Dusan Losic,1 Seung Jun Park,3 Jean-Francois Feller,2 TaeYoung Kim3 1School of Chemical Engineering, The University of Adelaide, North Terrace, Adelaide, SA, Australia; 2Smart Plastics Group, European University of Brittany (UEB, LIMATB-UBS, Lorient, France; 3Department of Bionanotechnology, Gachon University, Sujeong-gu, Seongnam-si, Gyeonggi-do South Korea Abstract: We report a high-performance chemiresistive sensor for detection of volatile organic compound (VOC vapors based on core-shell hybridized nanostructures of Fe3O4 magnetic nanoparticles (MNPs and poly(3,4-ethylenedioxythiophene (PEDOT-conducting polymers. The MNPs were prepared using microwave-assisted synthesis in the presence of polymerized ionic liquids (PILs, which were used as a linker to couple the MNP and PEDOT. The resulting PEDOT–PIL-modified Fe3O4 hybrids were then explored as a sensing channel material for a chemiresistive sensor to detect VOC vapors. The PEDOT–PIL-modified Fe3O4 sensor exhibited a tunable response, with high sensitivity (down to a concentration of 1 ppm and low noise level, to VOCs; these VOCs include acetone vapor, which is present in the exhaled breath of potential lung cancer patients. The present sensor, based on the hybrid nanostructured sensing materials, exhibited a 38.8% higher sensitivity and an 11% lower noise level than its PEDOT–PIL-only counterpart. This approach of embedding MNPs in conducting polymers could lead to the development of new electronic noses, which have significant potential for the use in the early diagnosis of lung cancer via the detection of VOC biomarkers. Keywords: hybrid nanomaterials, nanoparticle, conducting polymer, electronic nose, lung cancer detection

  5. Dissolution kinetics of volatile organic compound vapors in water: An integrated experimental and computational study

    Science.gov (United States)

    Mahmoodlu, Mojtaba G.; Pontedeiro, Elizabeth M.; Pérez Guerrero, Jesús S.; Raoof, Amir; Majid Hassanizadeh, S.; van Genuchten, Martinus Th.

    2017-01-01

    In this study we performed batch experiments to investigate the dissolution kinetics of trichloroethylene (TCE) and toluene vapors in water at room temperature and atmospheric pressure. The batch systems consisted of a water reservoir and a connected headspace, the latter containing a small glass cylinder filled with pure volatile organic compound (VOC). Results showed that air phase concentrations of both TCE and toluene increased relatively quickly to their maximum values and then became constant. We considered subsequent dissolution into both stirred and unstirred water reservoirs. Results of the stirred experiments showed a quick increase in the VOC concentrations with time up to their solubility limit in water. VOC vapor dissolution was found to be independent of pH. In contrast, salinity had a significant effect on the solubility of TCE and toluene vapors. VOC evaporation and vapor dissolution in the stirred water reservoirs followed first-order rate processes. Observed data could be described well using both simplified analytical solutions, which decoupled the VOC dynamics in the air and water phases, as well as using more complete coupled solutions. However, the estimated evaporation (ke) and dissolution (kd) rate constants differed by up to 70% between the coupled and uncoupled formulations. We also numerically investigated the effects of fluid withdrawal from the small water reservoir due to sampling. While decoupling the VOC air and water phase mass transfer processes produced unreliable estimates of kd, the effects of fluid withdrawal on the estimated rate constants were found to be less important. The unstirred experiments showed a much slower increase in the dissolved VOC concentrations versus time. Molecular diffusion of the VOCs within the aqueous phase became then the limiting factor for mass transfer from air to water. Fluid withdrawal during sampling likely caused some minor convection within the reservoir, which was simulated by increasing the

  6. Analysis of seven salad rocket (Eruca sativa) accessions: The relationships between sensory attributes and volatile and non-volatile compounds.

    Science.gov (United States)

    Bell, Luke; Methven, Lisa; Signore, Angelo; Oruna-Concha, Maria Jose; Wagstaff, Carol

    2017-03-01

    Sensory and chemical analyses were performed on accessions of rocket (Eruca sativa) to determine phytochemical influences on sensory attributes. A trained panel was used to evaluate leaves, and chemical data were obtained for polyatomic ions, amino acids, sugars and organic acids. These chemical data (and data of glucosinolates, flavonols and headspace volatiles previously reported) were used in Principal Component Analysis (PCA) to determine variables statistically important to sensory traits. Significant differences were observed between samples for polyatomic ion and amino acid concentrations. PCA revealed strong, positive correlations between glucosinolates, isothiocyanates and sulfur compounds with bitterness, mustard, peppery, warming and initial heat mouthfeel traits. The ratio between glucosinolates and sugars inferred reduced perception of bitter aftereffects. We highlight the diversity of E. sativa accessions from a sensory and phytochemical standpoint, and the potential for breeders to create varieties that are nutritionally and sensorially superior to existing ones.

  7. Validation of thermodesorption method for analysis of semi-volatile organic compounds adsorbed on wafer surface.

    Science.gov (United States)

    Hayeck, Nathalie; Gligorovski, Sasho; Poulet, Irène; Wortham, Henri

    2014-05-01

    To prevent the degradation of the device characteristics it is important to detect the organic contaminants adsorbed on the wafers. In this respect, a reliable qualitative and quantitative analytical method for analysis of semi-volatile organic compounds which can adsorb on wafer surfaces is of paramount importance. Here, we present a new analytical method based on Wafer Outgassing System (WOS) coupled to Automated Thermal Desorber-Gas chromatography-Mass spectrometry (ATD-GC-MS) to identify and quantify volatile and semi-volatile organic compounds from 6", 8" and 12" wafers. WOS technique allows the desorption of organic compounds from one side of the wafers. This method was tested on three important airborne contaminants in cleanroom i.e. tris-(2-chloroethyl) phosphate (TCEP), tris-(2-chloroisopropyl) phosphate (TCPP) and diethyl phthalate (DEP). In addition, we validated this method for the analysis and quantification of DEP, TCEP and TCPP and we estimated the backside organic contamination which may contribute to the front side of the contaminated wafers. We are demonstrating that WOS/ATD-GC-MS is a suitable and highly efficient technique for desorption and quantitative analysis of organophosphorous compounds and phthalate ester which could be found on the wafer surface.

  8. Volatile compounds and sensory characteristics of various instant teas produced from black tea.

    Science.gov (United States)

    Kraujalytė, Vilma; Pelvan, Ebru; Alasalvar, Cesarettin

    2016-03-01

    Various instant teas produced differently from black tea [freeze-dried instant tea (FDIT), spray-dried instant tea (SDIT), and decaffeinated instant tea (DCIT)], were compared for their differences in volatile compounds as well as descriptive sensory analysis (DSA). A total of 63 volatile compounds in all tea samples (eight aldehydes, ten alcohols, nine ketones, five esters, eight acids, ten terpenes/terpenoids, ten furans/furanones, two pyrroles, and one miscellaneous compound) were tentatively identified. Black tea, FDIT, SDIT, and DCIT contained 60, 55, 47, and 40 volatile compounds, respectively. Ten flavour attributes such as after taste, astringency, bitter, caramel-like, floral/sweet, green/grassy, hay-like, malty, roasty, and seaweed were identified. Intensities for a number of flavour attributes (except for caramel-like in SDIT and bitter and after taste in DCIT) were not significantly different (p>0.05) among tea samples. The present study suggests that instant teas can also be used as good alternative to black tea.

  9. Volatile compounds formation in alcoholic fermentation from grapes collected at 2 maturation stages: influence of nitrogen compounds and grape variety.

    Science.gov (United States)

    Martínez-Gil, Ana M; Garde-Cerdán, Teresa; Lorenzo, Cándida; Lara, José Félix; Pardo, Francisco; Salinas, M Rosario

    2012-01-01

    The aim of this work was to study the influence of nitrogen compounds on the formation of volatile compounds during the alcoholic fermentation carried out with 4 nonaromatic grape varieties collected at 2 different maturation stages. To do this, Monastrell, Merlot, Syrah, and Petit Verdot grapes were collected 1 wk before harvest and at harvest. Then, the musts were inoculated with the same Saccharomyces cerevisiae yeast strain and were fermented in the same winemaking conditions. Amino acids that showed the highest and the lowest concentration in the must were the same, regardless of the grape variety and maturation stage. Moreover, the consumption of amino acids during the fermentation increased with their concentration in the must. The formation of volatile compounds was not nitrogen composition dependent. However, the concentration of amino acids in the must from grapes collected 1 wk before harvest can be used as a parameter to estimate the concentration of esters in wines from grapes collected at harvest and therefore to have more information to know the grape oenological capacity. Application of principal components analysis (PCA) confirmed the possibility to estimate the concentration of esters in the wines with the concentration of nitrogen compounds in the must.

  10. Development of a fast GC/MS-system for airborne measurements of Volatile Organic Compounds

    Science.gov (United States)

    Wenk, Ann-Kathrin; Wegener, Robert; Hofzumahaus, Andreas; Wahner, Andreas

    2010-05-01

    Volatile Organic Compounds (VOC) determine the radical chemistry of the atmosphere. They can serve both as sources, or sinks for radicals. Mass spectrometry linked to gas chromatography (GC/MS) is a widespread technique in environmental analysis since it can be used to separate and analyze any compound which can be evaporated and pass the analytical column with very high precision and a good sensitivity. The use of special chromatographic phases and long capillary columns enables the quantification of a wide range of compounds with little interference from other sample constituents. An in situ GC/MS consists in principle of three compartments, 1) a preconcentration unit where the sample is extracted from the air, focussed onto a small volume and volatilized, 2) a chromatographic system where the analytes are separated on the analytical column and 3) a mass spectrometer where the compounds are ionized and detected. VOC have to be preconcentrated due to their low concentration level and in order to get enough sensitivity for analysis. The aim of this project was to develop an in situ GC/MS system to analyze volatile Nonmethane Hydrocarbons (NMHC) and Oxygenated Volatile Organic Compounds (OVOC) for the High Altitude and LOng Range Research Aircraft (HALO). In contrast to other analytical instruments a GC/MS works discontinuously. The preconcentration unit is either heated up when the compounds are volatilized or cooled down when substances are adsorbed. The same is true for the GC oven. It is heated up when the compounds are separated or it is cooled down to be ready for the next injection. On a system with a single GC oven, these processes will inevitably lengthen the whole analytical procedure. To speed up the analytical process the GC/MS system described here was equipped with two GC ovens and two adsorption units. While the components are adsorbed in one adsorption unit, in the other unit the components are desorbed and transferred to the GC unit. The second GC

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

    Science.gov (United States)

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

    2009-02-01

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

  12. Volatile compounds in medlar fruit (Mespilus germanica L. at two ripening stages

    Directory of Open Access Journals (Sweden)

    Veličković Milovan M.

    2013-01-01

    Full Text Available Medlar is the fruit of Mespilus germanica L. in the family of Rosaceae. The fruit can be eaten only if ‘bletted’ (softened by frost or longer storage. The effect of the maturation stages on the volatile compounds of the medlar fruit was investigated during two different stages. Volatile flavour substances were isolated from the minced pulp of unripe and full ripe medlar fruits by simultaneous steam distillation extraction (SDE with methilen chloride as the extracting solvent. The concentrate was analysed by GC-FID-MS. Hexanoic and hexadecanoic acids were the predominant acids, hexanal and (E-2-hexenal were the predominant aldehydes, (Z-3-hexenol and hexanol were the predominant alcohols, with p-cymene, terpinen-4-ol, and γ-terpiene (the terpenes responsible for the characteristic medlar flavour being also present. The C6 aliphatic compounds, such as hexanal and (E-2-hexenal, were observed as the major volatile constituents in the green stage. In contrast, hexanol and (Z-3-hexenol were the main volatiles in ripe fruits.

  13. Effect of immobilized Lactobacillus casei on volatile compounds of heat treated probiotic dry-fermented sausages.

    Science.gov (United States)

    Sidira, Marianthi; Kandylis, Panagiotis; Kanellaki, Maria; Kourkoutas, Yiannis

    2015-07-01

    The effect of the amount of immobilized Lactobacillus casei ATCC 393 on wheat grains on the generation of volatile compounds during the production of heat treated probiotic dry-fermented sausages was investigated. For comparison reasons, sausages containing free L. casei cells or no starter culture as well as a similar commercial product were also included in the study. Samples ripened for 8 days and heat treated to 70-72°C for 8-10 min were subjected to Solid Phase Microextraction (SPME) Gas Chromatography/Mass Spectrometry (GC/MS) analysis. The starter culture affected significantly the production of volatile compounds. The highest content of esters and alcohols was observed in the sample containing 30 g of immobilized cells/kg of stuffing mixture, while the highest concentration of organic acids was observed in the sausages with no starter culture. In contrast, the commercial product contained the lowest concentration of volatiles. Principal component analysis of the semi-quantitative data revealed that the volatile composition was affected primarily by the nature and concentration of the starter culture.

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

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    Annalisa eGiorgio

    2015-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Teresa Weise

    2012-04-01

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

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

    Science.gov (United States)

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

    2012-01-01

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

  17. Effect of gamma radiation on the content {beta}-carotene and volatile compounds of cantaloupe melon

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Stefania P. de; Cardozo, Monique; Lima, Keila dos S.C.; Lima, Antonio L. dos S., E-mail: keila@ime.eb.br, E-mail: santoslima@ime.eb.br [Departamento de Quimica - IME - Instituto Militar de Engenharia, RJ (Brazil)

    2011-07-01

    The Japanese melon or cantaloupe (Cucumis melo L.) is characterized by fruits with almost 1.0 Kg, pulp usually salmon and musky scent. The fruits when ripe are sensitive to post harvest handling. This low transport resistance and reduced shelf-life makes it necessary to delay the ripening of fruit. In this way the use of irradiation technique is a good choice. Irradiation is the process of exposing food to high doses of gamma rays. The processing of fruits and vegetables with ionizing radiation has as main purpose to ensure its preservation. However, like other forms of food processing, irradiation may cause changes in chemical composition and nutritional value. This study aims to assess possible changes in carotene content and volatile compounds caused by exposure of cantaloupe melon fruit to gamma irradiation. Irradiation of the samples occurred in Centro Tecnologico do Exercito (Guaratiba-RJ), using Gamma irradiator (Cs{sub 137} source, dose rate 1.8 kGy/h), being applied 0.5 and 1.0 kGy doses and separated a control group not irradiated. Carotenoids were extracted with acetone and then suffered partition to petroleum ether, solvent was removed under nitrogen flow and the remainder dissolved in acetone again. The chromatographic analysis was performed using a Shimadzu gas chromatograph, with C30 column. For volatile compounds, we used gas chromatography (GC) associated with mass (MS). As a result, it was verified in analysis of carotenoids that cantaloupe melon is rich in {beta}-carotene. Both total content of carotenoids and specific {beta}-carotene amount wasn't suffer significant reduction in irradiated fruits at two doses, demonstrating that the irradiation process under these conditions implies a small loss of nutrients. The major volatile compounds were: 2-methyl-1-butyl acetate, ethyl hexanoate, n-hexyl acetate, benzyl acetate, 6-nonenyl acetate and {alpha} -terpinyl acetate. For all compounds we observed an increase in the volatile content in 0.5 k

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

    Science.gov (United States)

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

    2016-09-01

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

  19. Volatile organic compounds and Photobacterium phosphoreum associated with spoilage of modified-atmosphere-packaged raw pork

    DEFF Research Database (Denmark)

    Nieminen, Timo T.; Dalgaard, Paw; Björkroth, Johanna

    2016-01-01

    Accumulation of volatile organic compounds was monitored in association with sensory quality, bacterial concentrations and culture-independent microbial community analyses in raw pork loin and pork collar during storage under high-oxygen modified atmosphere at +4°C. Of the 48 volatile compounds....... According to the culture-dependent and culture-independent characterization of bacterial communities, Brochothrix thermosphacta, lactic acid bacteria (Carnobacterium, Lactobacillus, Lactococcus, Leuconostoc, Weissella) and Photobacterium spp. predominated in pork samples. Photobacterium spp., typically...... not associated with spoilage of meat, were detected also in 8 of the 11 retail packages of pork investigated subsequently. Eleven isolates from the pork samples were shown to belong to Photobacterium phosphoreum by phenotypic tests and sequencing of the 16S rRNA and gyrB gene fragments. Off-odors in pork samples...

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

    DEFF Research Database (Denmark)

    Poulsen, Henrik Vestergaard; Jensen, Bent Borg; Finster, Kai

    2012-01-01

    Aims: To investigate the production of volatile sulphur compounds (VSC) in segments of the large intestine of pigs and to assess the impact of diet on this production. Methods and Results: Pigs were fed two diets based on either wheat and barley (STD) or wheat and dried distillers grains with sol......Aims: To investigate the production of volatile sulphur compounds (VSC) in segments of the large intestine of pigs and to assess the impact of diet on this production. Methods and Results: Pigs were fed two diets based on either wheat and barley (STD) or wheat and dried distillers grains...... significantly higher in the STD group. Conversely, the net methanethiol production rate was significantly higher in the DDGS-group, while no difference was observed for dimethyl sulphide. The number of sulphate reducing bacteria and total bacteria were determined by quantitative PCR and showed a significant...

  1. Volatile organic compounds in pharmacy – the range of the problem

    Directory of Open Access Journals (Sweden)

    Marzena Jamrógiewicz

    2013-09-01

    Full Text Available The sensitivity and chemical instability of the active pharmaceutical ingredients (API may result in the formation and emission of volatile substances which affect not only the stability of the medicinal product, but also leads to changes of physicochemical properties, causing negative pharmacologic effects sometimes toxic. For this reason, it is important to conduct routine stability tests, as well as, to determine gaseous degradation products using modern analytical methods, often unconventional. Knowledge of medicinal chemistry, physical chemistry, technology and toxicology is needed to provide a stable form of the drug and its utmost therapeutic effect. Available guidelines on determined volatile organic compounds (VOCs present in samples of drug substances have been verified , types of VOCs have been specified and classified. Current literature reviewed shows the results of determination of VOCs in active drug compounds and medicinal products, including discussion on various possibilities of their detection and identification. Currently used methods are based on gas chromatography and ion mobility spectrometry IMS.

  2. Prediction of air to liver partition coefficient for volatile organic compounds using QSAR approaches.

    Science.gov (United States)

    Dashtbozorgi, Zahra; Golmohammadi, Hassan

    2010-06-01

    In this work a quantitative structure-activity relationship (QSAR) technique was developed to investigate the air to liver partition coefficient (log Kliver) for volatile organic compounds (VOCs). Suitable set of molecular descriptors was calculated and the important descriptors were selected by GA-PLS methods. These variables were served as inputs to generate neural networks. After optimization and training of the networks, they were used for the calculation of log Kliver for the validation set. The root mean square errors for the neural network calculated log Kliver of training, test, and validation sets are 0.100, 0.091, and 0.112, respectively. Results obtained reveal the reliability and good predictivity of neural network for the prediction of air to liver partition coefficient for volatile organic compounds.

  3. [Emission characteristics and hazard assessment analysis of volatile organic compounds from chemical synthesis pharmaceutical industry].

    Science.gov (United States)

    Li, Yan; Wang, Zhe-Ming; Song, Shuang; Xu, Zhi-Rong; Xu, Ming-Zhu; Xu, Wei-Li

    2014-10-01

    In this study, volatile organic compounds (VOCs) released from chemical synthesis pharmaceutical industry in Taizhou, Zhejiang province were analyzed quantitatively and qualitatively. The total volatile organic compounds (TVOCs) was in the range of 14.9-308.6 mg · m(-3). Evaluation models of ozone formation potentials (OFP) and health risk assessment were adopted to preliminarily assess the environmental impact and health risk of VOCs. The results showed that the values of OFP of VOCs were in the range of 3.1-315.1 mg · m(-3), based on the maximum incremental reactivity, the main principal contribution was toluene, tetrahydrofuran (THF), acetic ether etc. The non-carcinogenic risk and the carcinogen risk fell in the ranges of 9.48 x 10(-7)-4.98 x 10(-4) a(-1) and 3.17 x 10(-5)- 6.33 x 10(-3). The principal contribution of VOCs was benzene, formaldehyde and methylene chloride.

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

    Science.gov (United States)

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

    2013-11-01

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

  5. Antimicrobial and Volatile Compounds Study of Four Spices Commonly Used in Indonesian Culinary

    OpenAIRE

    Hamad, Alwani; Mahardika, M. Gigih Panji; Istifah, Istifah; Hartanti, Dwi

    2016-01-01

    The n-hexane extracts of the aerial parts of Ocimum x citriodorum and the leaves of Cymbopogon citratus, Syzygium aromaticum and Syzygium polyanthum were evaluated for their antimicrobial activity against some food borne microorganisms. Their volatile compounds were analyzed by gas chromatography/mass spectrometry (GC/MS). All extracts inhibited the growth of Bacillus subtilis. The extract of S. polyanthum showed the strongest inhibitory activity against Salmonella typhimurium. The growth of ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-07-01

    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 needs of the customer.

  7. A case study: shelf-life of smoked herring fillets by volatile compounds analysis.

    Directory of Open Access Journals (Sweden)

    Cristian Bernardi

    2014-02-01

    Full Text Available Two different products of vacuum packed cold smoked herrings were analyzed at time intervals in order to evaluate the efficiency of the processing and product stability. Microbiological total counts, lactic acid bacteria, total coliforms, pH, water activity, water content, salt content (WPS were determined. Differences in hygienic conditions and salt content were found. Principal components analysis (PCA of volatile compounds determined by GC-MS analysis allowed the differentiation of the processing.

  8. Non-methane volatile organic compound flux from a subarctic mire in Northern Sweden

    OpenAIRE

    Bäckstrand, Kristina; Crill, Patrick M.; Mastepanov, Mikhail; Christensen, Torben R.; Bastviken, David

    2011-01-01

    Biogenic NMVOCs are mainly formed by plants and microorganisms. They have strong impact on the local atmospheric chemistry when emitted to the atmosphere. The objective of this study was to determine if there are significant emissions of non-methane volatile organic compounds (NMVOCs) from a subarctic mire in northern Sweden. Subarctic peatlands in discontinuous permafrost regions are undergoing substantial environmental changes due to their high sensitivity to climate warming and there is ne...

  9. Sensory eye irritation in humans exposed to mixtures of volatile organic compounds

    DEFF Research Database (Denmark)

    Hempel-Jørgensen, Anne Hempel; Kjærgaard, Søren K.; Mølhave, Lars;

    1999-01-01

    Eight subjects participated in a controlled eyes-only exposure study of human sensory irritation in ocular mucosal tissue. The authors investigated dose-response properties and the additive effects of three mixtures of volatile organic compounds. The dose-response relationships for these mixtures...... to as simple agonism. Finally, the authors addressed the comparability of two methods to measure sensory irritation intensity (visual analogue scale and a comparative scale). The results indicated that the two rating methods produced highly comparable results....

  10. Contribution of a selected fungal population to the volatile compounds on dry-cured ham.

    Science.gov (United States)

    Martín, Alberto; Córdoba, Juan J; Aranda, Emilio; Córdoba, M Guía; Asensio, Miguel A

    2006-07-01

    Dry-cured ham is obtained after several months of ripening. Different fungi strive on the surface, including toxigenic molds. Proteolysis and lipolysis by the endogenous and microbial enzymes seem to play a decisive role in the generation of flavor precursors in dry-cured meat products. In addition, fungi show a positive impact on the volatile compounds of ripened pork loins. However, the contribution of the fungal population to flavor formation in dry-cured ham remains unclear. One selected strain each of Penicillium chrysogenum and Debaryomyces hansenii was inoculated as starter cultures on dry-cured ham. Volatile compounds extracted by solid phase micro-extraction technique were analyzed by gas chromatography/mass spectrometry. A trained panel evaluated flavor and texture of fully ripened hams. The wild fungal population on non-inoculated control hams correlates with higher levels of short chain aliphatic carboxylic acids and their esters, branched carbonyls, branched alcohols, and some sulfur compounds, particularly at the outer muscle. Conversely, P. chrysogenum and D. hansenii seem to be responsible for higher levels of long chain aliphatic and branched hydrocarbons, furanones, long chain carboxylic acids and their esters. The very limited impact of P. chrysogenum on pyrazines in inoculated hams can be due to the activity of the yeast. Lower levels for some of the more volatile linear carbonyls at the ham surface suggest an anti-oxidant effect by micro-organisms. The differences in volatile compounds did not show a neat impact on flavor in the sensorial analysis. Nonetheless, inoculated hams got a better overall acceptability, which has to be attributed to their improved texture. The lower toughness of inoculated hams is a direct consequence of an early settling of a highly proteolytic mold. Thus, the use of selected fungi as starter cultures may be useful to obtain high-quality and safe dry-cured ham.

  11. Volatile Organic Compound (VOC) Testing at Building 348, Kelly AFB, Texas.

    Science.gov (United States)

    1987-11-01

    At the request of HQ AFLC/ SGB , the USAFOEHL conducted a stack sampling survey to determine total volatile organic compounds (VOC) being emitted from...Occupational and Environmental Health Laboratory (USAFOEHL/ECQ). The survey was requested by HQ AFLC/ SGB .to estimate VOC emissions through each of...stardards. 2. Range and Sensitivity 2.1 This method was validated over the range of 1417-5940 mg/M at an atmospheric temperature and pressure of 24 0C

  12. Quartz Crystal Microbalance: A tool for analyzing loss of volatile compounds, gas sorption, and curing kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Bajric, Sendin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-16

    Los Alamos National Laboratory (LANL) has recently procured a quartz crystal microbalance (QCM). Current popular uses are biological sensors, surface chemistry, and vapor detection. LANL has projects related to analyzing curing kinetics, measuring gas sorption on polymers, and analyzing the loss of volatile compounds in polymer materials. The QCM has yet to be employed; however, this review will cover the use of the QCM in these applications and its potential.

  13. [Behavioral response of Anopheles albimanus to volatile compounds collected inside houses from the south of Chiapas, Mexico].

    Science.gov (United States)

    Ríos-Delgado, Silvany Mayoly; Rodríguez-Ramírez, Américo David; Cruz-López, Leopoldo; Escobar-Pérez, Luis Alonso; Aburto-Juárez, Ma de Lourdes; Torres-Estrada, José Luis

    2008-01-01

    To determine effects of volatile compounds in homes on the behavioral response of Anopheles albimanus. The study was conducted in January 2006, in the village of Nueva Independencia village, Suchiate, Chiapas. Volatile compounds were collected inside homes and the extracts were tested on unfed females in a Y-olfactometer. Extracts were analyzed in a gas chromatography-mass spectrometry system (GC-MS). Twenty eight extracts were obtained, twelve presented attraction and two repellency responses. GC-MS analyses of the extracts indicated variation in the volatile compound present in the extracts, but could not associated specific compounds with any particular effect. Within homes, volatiles presented attraction and repellency responses to An. albimanus. A definate pattern concerning the presence of a characteristic chemical compound and the observed response was not found.

  14. A non-invasive method for in vivo skin volatile compounds sampling.

    Science.gov (United States)

    Jiang, Ruifen; Cudjoe, Erasmus; Bojko, Barbara; Abaffy, Tatjana; Pawliszyn, Janusz

    2013-12-04

    The use of volatile organic compounds (VOCs) emanating from human skin presents great potential for skin disease diagnosis. These compounds are emitted at very low concentrations. Thus, the sampling preparation step needs to be implemented before gas chromatography-mass spectrometry (GC-MS) analysis. In this work, a simple, non-invasive headspace sampling method for volatile compounds emanating from human skin is presented, using thin film as the extraction phase format. The proposed method was evaluated in terms of reproducibility, membrane size, extraction mode and storage conditions. First, the in vial sampling showed an intra- and inter-membrane RSD% less than 9.8% and 8.2%, respectively, which demonstrated that this home-made skin volatiles sampling device was highly reproducible with regard to intra-, inter-membrane sampling. The in vivo sampling was influenced not only by the skin metabolic status, but also by environmental conditions. The developed sampling set-up (or "membrane sandwich") was used to compare two different modes of sampling: headspace and direct sampling. Results demonstrated that headspace sampling had significantly reduced background signal intensity, indicating minimized contamination from the skin surface. In addition, membrane storage conditions both before and after sampling were fully investigated. Membranes stored in dry ice for up to 72 h after collection were tested and showed no or minimal change in volatile profiles. This novel skin volatile compounds sampling approach coupled with gas chromatography-mass spectrometry (GC-MS) can achieve reproducible analysis. This technique was applied to identify the biomarkers of garlic intake and alcohol ingestion. Dimethyl sulphone, allyl methyl sulfide and allyl mercaptan, as metabolites of garlic intake, were detected. In addition, alcohol released from skin was also detected using our "membrane-sandwich" sampling. Using the same approach, we analyzed skin VOCs from upper back, forearm and

  15. Biofiltration kinetics for volatile organic compounds (VOCs) and development of a structure-biodegradability relationship

    Energy Technology Data Exchange (ETDEWEB)

    Govind, R.; Wang, Z. [Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering; Bishop, D.F. [Environmental Protection Agency, Cincinnati, OH (United States). National Risk Management Research Lab.

    1997-12-31

    In recent years, regulation of hazardous air pollutants under the Clean Air Act and its amendments, has emerged as a major environmental issue. Major sources of volatile organic compounds (VOCs) in air are chemical production plants, manufacturing sites using common solvents, combustion sources, and waste treatment operations, such as waste water treatment plants, vacuum extraction of contaminated soils, and ground water stripping operations. Biofiltration is an emerging technology for treatment of biodegradable volatile organic compounds (VOCs) present in air. In biofiltration, the contaminants are contacted with active microorganisms present either in naturally bioactive materials, such as soil, peat, compost, etc., or immobilized on an inactive support media. Design of biofilters requires information on biodegradation kinetics which controls biofilter size. In this paper, an experimental microbiofilter system is presented which can be used to measure biofiltration kinetics for any volatile organic compound. A mathematical model is used to derive the Monod biokinetic parameters from the experimental data. Finally, a structure-bioactivity relationship is derived for estimating the biofiltration biokinetic parameters for a variety of VOCs.

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

    Science.gov (United States)

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

    2015-01-01

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

  17. A study of volatile compounds in the breath of children with type 1 diabetes

    CERN Document Server

    Stevens, S; Wei, C; Greenwood, R; Hamilton-Shield, J; Costello, B de Lacy; Ratcliffe, N; Probert, C

    2013-01-01

    A pilot study of exhaled volatile compounds and their correlation with blood glucose levels in eight children with type 1 diabetes is reported. Five paired blood and breath samples were obtained from each child over a 6 hour period. The blood glucose concentration ranged from 41.4 to 435.6 mg/dL. Breath samples were collected in Tedlar bags and immediately evacuated through thermal desorption tubes packed with Carbopack B and C. The VOCs were later recovered by thermal desorption and analysed using gas chromatography mass spectrometry. The study identified 74 volatile compounds present in at least 10% of the patient samples. Of these 74 volatiles 36 were found in all patient samples tested. Further analysis of the 36 compounds found that none showed significant overall correlation with blood glucose levels. Isoprene showed a weak negative correlation with blood glucose levels. Acetone was found to have no correlation with blood glucose levels for the patients studied. Some patients showed significant individu...

  18. Ultrasound-assisted extraction of volatile compounds from industrial Cannabis sativa L. inflorescences

    Directory of Open Access Journals (Sweden)

    C. Da Porto

    2014-02-01

    Full Text Available Summary. This study investigated the use of ultrasound-assisted extraction (UAE to recovery  volatile compounds from the inflorescences of a fiber type Cannabis sativa L. cultivar. The results show that ultrasonic treatment not longer than 5 min allows to obtain an enhanced concentration of terpenes in comparison with maceration. Instead, an ultrasonic treatment longer than 5 min increased  the concentration of δ-9-tetraidrocannabinol (THC. A preliminary screening of cannabis inflorescences scent was performed by headspace solid-phase microextraction (HS-SPME with gas chromatography-mass spectrometry (GC-MS avoiding the chemical modification and artifact formation that can occur in conventional methods . Industrial relevance. Inflorescences of fiber type Cannabis sativa cultivars are generally considered waste parts for fiber industry, although the inflorescences’ volatiles are pleasant to the human sensory system. Cannabis scent originate from volatile monoterpenes and sesquiterpenes . Traditionally, the recovery of floral fragrances from plants is by water distillation (hydro-distillation or steam distillation to produce essential oils. However, these techniques take at least several hours and require the application of heating, which can produce the degradation of thermo labile compounds present in the starting plant material. Ultrasound-assisted extraction can be use as alternative method to extract aroma compounds from inflorescences of fiber type  Cannabis sativa. The extracts so obtained could be used as ingredients for perfumes (cosmetic industry or flavorings for beverages (food industry.Keywords. Ultrasound; Extraction; Cannabis sativa L.; terpenes; THC; HS-SPME

  19. Nutritional Value and Volatile Compounds of Black Cherry (Prunus serotina Seeds

    Directory of Open Access Journals (Sweden)

    Leticia García-Aguilar

    2015-02-01

    Full Text Available Prunus serotina (black cherry, commonly known in Mexico as capulín, is used in Mexican traditional medicine for the treatment of cardiovascular, respiratory, and gastrointestinal diseases. Particularly, P. serotina seeds, consumed in Mexico as snacks, are used for treating cough. In the present study, nutritional and volatile analyses of black cherry seeds were carried out to determine their nutraceutical potential. Proximate analysis indicated that P. serotina raw and toasted seeds contain mostly fat, followed by protein, fiber, carbohydrates, and ash. The potassium content in black cherry raw and toasted seeds is high, and their protein digestibility-corrected amino acid scores suggest that they might represent a complementary source of proteins. Solid phase microextraction and gas chromatography/flame ionization detection/mass spectrometry analysis allowed identification of 59 and 99 volatile compounds in the raw and toasted seeds, respectively. The major volatile compounds identified in raw and toasted seeds were 2,3-butanediol and benzaldehyde, which contribute to the flavor and odor of the toasted seeds. Moreover, it has been previously demonstrated that benzaldehyde possesses a significant vasodilator effect, therefore, the presence of this compound along with oleic, linoleic, and α-eleostearic fatty acids indicate that black cherry seeds consumption might have beneficial effects on the cardiovascular system.

  20. Development of a direct exposure system for studying the mechanisms of central neurotoxicity caused by volatile organic compounds

    OpenAIRE

    2015-01-01

    Many volatile organic compounds (VOCs) used in work places are neurotoxic. However, it has been difficult to study the cellular mechanisms induced by a direct exposure to neurons because of their high volatility. The objective of this study was to establish a stable system for exposing brain slices to VOCs. With a conventional recording system for brain slices, it is not possible to keep a constant bath concentration of relatively highly volatile solvents, e.g. 1-bromopropane (1-BP). Here we ...

  1. Volatile compounds emission and health risk assessment during composting of organic fraction of municipal solid waste

    DEFF Research Database (Denmark)

    Mustafa, Muhammad Farooq; Liu, Yanjun; Duan, Zhenhan

    2017-01-01

    Degradation of mechanically sorted organic fraction (MSOF) of municipal solid waste in composting facilities is among the major contributors of volatile compounds (VCs) generation and emission, causes nuisance problems and health risks on site as well as in the vicinages. The aim of current study...... was to determine the seasonal (summer and winter) variation and human health risk assessment of VCs in the ambient air of different processing units in MSOF at composting plant in China. Average concentration of VCs was 58.50 and 138.03 mg/m3 in summer and winter respectively. Oxygenated compounds were found...

  2. Bioactive and volatile organic compounds in Southern Brazilian blackberry (Rubus Fruticosus fruit cv. Tupy

    Directory of Open Access Journals (Sweden)

    Andressa Carolina Jacques

    2014-09-01

    Full Text Available Blackberry (Rubus fruticosus, cultivar Tupy, an expanding fruit crop in southern Brazil, is greatly appreciated for its flavor and bioactive potential with limited characterization of its metabolite content. The purpose of this study was to characterize the bioactive and volatile organic compound (VOC content of mature blackberry fruit of cultivar Tupy. Gallic acid, (--epicatechin, ferulic acid, and quercetin were the main phenolic compounds found in mature fruit. Among the VOCs identified in 'Tupy' blackberry were important flavor components characteristic of fruit berries, including hydrocarbons, alcohols, aldehydes, ketones, esters, and terpenoids. Some of the VOCs had not been previously found in blackberry, while others have been associated with typical blackberry flavor.

  3. Estimation of the Accuracy of Method for Quantitative Determination of Volatile Compounds in Alcohol Products

    CERN Document Server

    Charepitsa, S V; Zadreyko, Y V; Sytova, S N

    2016-01-01

    Results of the estimation of the precision for determination volatile compounds in alcohol-containing products by gas chromatography: acetaldehyde, methyl acetate, ethyl acetate, methanol, isopropyl alcohol, propyl alcohol, isobutyl alcohol, butyl alcohol, isoamyl alcohol are presented. To determine the accuracy, measurements were planned in accordance with ISO 5725 and held at the gas chromatograph Crystal-5000. Standard deviation of repeatability, intermediate precision and their limits are derived from obtained experimental data. The uncertainty of the measurements was calculated on the base of an "empirical" method. The obtained values of accuracy indicate that the developed method allows measurement uncertainty extended from 2 to 20% depending on the analyzed compound and measured concentration.

  4. Volatile organic compound concentrations and emission rates measured over one year in a new manufactured house

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, Alfred T.; Nabinger, Steven J.; Persily, Andrew K.

    2004-09-01

    A study to measure indoor concentrations and emission rates of volatile organic compounds (VOCs), including formaldehyde, was conducted in a new, unoccupied manufactured house installed at the National Institute of Standards and Technology (NIST) campus. The house was instrumented to continuously monitor indoor temperature and relative humidity, heating and air conditioning system operation, and outdoor weather. It also was equipped with an automated tracer gas injection and detection system to estimate air change rates every 2 h. Another automated system measured indoor concentrations of total VOCs with a flame ionization detector every 30 min. Active samples for the analysis of VOCs and aldehydes were collected indoors and outdoors on 12 occasions from August 2002 through September 2003. Individual VOCs were quantified by thermal desorption to a gas chromatograph with a mass spectrometer detector (GC/MS). Formaldehyde and acetaldehyde were quantified by high performance liquid chromatography (HPLC). Weather conditions changed substantially across the twelve active sampling periods. Outdoor temperatures ranged from 7 C to 36 C. House air change rates ranged from 0.26 h{sup -1} to 0.60 h{sup -1}. Indoor temperature was relatively constant at 20 C to 24 C for all but one sampling event. Indoor relative humidity (RH) ranged from 21% to 70%. The predominant and persistent indoor VOCs included aldehydes (e.g., formaldehyde, acetaldehyde, pentanal, hexanal and nonanal) and terpene hydrocarbons (e.g., a-pinene, 3-carene and d-limonene), which are characteristic of wood product emissions. Other compounds of interest included phenol, naphthalene, and other aromatic hydrocarbons. VOC concentrations were generally typical of results reported for other new houses. Measurements of total VOCs were used to evaluate short-term changes in indoor VOC concentrations. Most of the VOCs probably derived from indoor sources. However, the wall cavity was an apparent source of

  5. Release of volatile organic compounds (VOCs from the lung cancer cell line CALU-1 in vitro

    Directory of Open Access Journals (Sweden)

    Schubert Jochen

    2008-11-01

    Full Text Available Abstract Background The aim of this work was to confirm the existence of volatile organic compounds (VOCs specifically released or consumed by lung cancer cells. Methods 50 million cells of the human non-small cell lung cancer (NSCLC cell line CALU-1 were incubated in a sealed fermenter for 4 h or over night (18 hours. Then air samples from the headspace of the culture vessel were collected and preconcentrated by adsorption on solid sorbents with subsequent thermodesorption and analysis by means of gas chromatography mass spectrometry (GC-MS. Identification of altogether 60 compounds in GCMS measurement was done not only by spectral library match, but also by determination of retention times established with calibration mixtures of the respective pure compounds. Results The results showed a significant increase in the concentrations of 2,3,3-trimethylpentane, 2,3,5-trimethylhexane, 2,4-dimethylheptane and 4-methyloctane in the headspace of CALU-1 cell culture as compared to medium controls after 18 h. Decreased concentrations after 18 h of incubation were found for acetaldehyde, 3-methylbutanal, butyl acetate, acetonitrile, acrolein, methacrolein, 2-methylpropanal, 2-butanone, 2-methoxy-2-methylpropane, 2-ethoxy-2-methylpropane, and hexanal. Conclusion Our findings demonstrate that certain volatile compounds can be cancer-cell derived and thus indicative of the presence of a tumor, whereas other compounds are not released but seem to be consumed by CALU-1 cells.

  6. Determination of volatile organic compounds, catechins, caffeine and theanine in Jukro tea at three growth stages by chromatographic and spectrometric methods.

    Science.gov (United States)

    Jeon, Dong Bok; Hong, Young Shin; Lee, Ga Hyun; Park, Yu Min; Lee, Cheong Mi; Nho, Eun Yeong; Choi, Ji Yeon; Jamila, Nargis; Khan, Naeem; Kim, Kyong Su

    2017-03-15

    Tea contains characteristic volatile organic compounds, polyphenols, caffeine and catechins, and is therefore among the most widely consumed beverages all over the world. In this study, fresh Jukro tea leaves collected from Damyang-gun (Jeollanam-do) at 40, 60 and 90day growth stages, were semi-fermented. The volatile organic compounds (VOCs) were extracted by simultaneous distillation-solvent extraction (SDE) and analyzed by gas chromatography/mass spectrometry (GC/MS). Catechins, caffeine and theanine were analyzed by high performance liquid chromatography (HPLC). A total of 159 VOCs were identified in the analyzed Jukro tea leaves. Comparatively, the increase in the concentrations of VOCs was high in 60day leaves. The content of catechins increased along the three growth stages, whereas caffeine, compared to 90day leaves, was higher for 40 and 60day leaves. Based on the results, the 60day leaves were found to be the most suitable and useful for making semi-fermented Jukro tea.

  7. Identification, synthesis, and characterization of novel sulfur-containing volatile compounds from the in-depth analysis of Lisbon lemon peels (Citrus limon L. Burm. f. cv. Lisbon).

    Science.gov (United States)

    Cannon, Robert J; Kazimierski, Arkadiusz; Curto, Nicole L; Li, Jing; Trinnaman, Laurence; Jańczuk, Adam J; Agyemang, David; Da Costa, Neil C; Chen, Michael Z

    2015-02-25

    Lemons (Citrus limon) are a desirable citrus fruit grown and used globally in a wide range of applications. The main constituents of this sour-tasting fruit have been well quantitated and characterized. However, additional research is still necessary to better understand the trace volatile compounds that may contribute to the overall aroma of the fruit. In this study, Lisbon lemons (C. limon L. Burm. f. cv. Lisbon) were purchased from a grove in California, USA, and extracted by liquid-liquid extraction. Fractionation and multidimensional gas chromatography-mass spectrometry were utilized to separate, focus, and enhance unidentified compounds. In addition, these methods were employed to more accurately assign flavor dilution factors by aroma extract dilution analysis. Numerous compounds were identified for the first time in lemons, including a series of branched aliphatic aldehydes and several novel sulfur-containing structures. Rarely reported in citrus peels, sulfur compounds are known to contribute significantly to the aroma profile of the fruit and were found to be aroma-active in this particular study on lemons. This paper discusses the identification, synthesis, and organoleptic properties of these novel volatile sulfur compounds.

  8. RECEPTOR MODEL COMPARISONS AND WIND DIRECTION ANALYSES OF VOLATILE ORGANIC COMPOUNDS AND SUBMICROMETER PARTICLES IN AN ARID, BINATIONAL, URBAN AIRSHED

    Science.gov (United States)

    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...

  9. Assessment of dispersive liquid-liquid microextraction conditions for gas chromatography time-of-flight mass spectrometry identification of organic compounds in honey.

    Science.gov (United States)

    Moniruzzaman, M; Rodríguez, I; Rodríguez-Cabo, T; Cela, R; Sulaiman, S A; Gan, S H

    2014-11-14

    The suitability of the dispersive liquid-liquid microextraction (DLLME) technique for gas chromatography (GC) characterization of minor organic compounds in honey samples is evaluated. Under optimized conditions, samples were pre-treated by liquid-liquid extraction with acetonitrile followed by DLLME using carbon tetrachloride (CCl4, 0.075 mL) as extractant. The yielded settled phase was analyzed by GC using high resolution time-of-flight (TOF) mass spectrometry (MS). The whole sample preparation process is completed in approximately 10 min, with a total consumption of organic solvents below 4 mL, relative standard deviations lower than 12% and with more than 70 organic compounds, displaying linear retention index in the range from 990 to 2900, identified in the obtained extracts. In comparison with HS SPME extraction, higher peak intensities were attained for most volatile and semi-volatile compounds amenable to both extraction techniques. Furthermore, other species such as highly polar and water soluble benzene acids, long chain fatty acids, esters and flavonoids, which are difficult to concentrate by HS SPME, could be identified in DLLME extracts. Some of the compounds identified in DLLME extracts have been proposed as useful for samples classification and/or they are recognized as markers of honeys from certain geographic areas.

  10. PERUBAHAN KOMPOSISI VOLATIL DAGING BUAH MANGGA "KENSINGTON PRIDE" SELAMA PEMASAKAN [Changes in Volatile Compound Composition of Kensington Pride Mango Pulp During Fruit Ripening

    Directory of Open Access Journals (Sweden)

    Herianus J.D Lalel

    2003-08-01

    Full Text Available Volatile compounds of ‘Kesington Pride’ mango produced from the pulp during fruit ripening were studied using headspace solid-phase microextraction (SPME as a sampling method and gas chromatography with a flame ionisation detector (GC-FID and gas chromatography mass spectrophotometry (GC-MS for analysis. Ethylene production and respiration reached a peak on the second and third day of ripening, respectively. Seventy-eight volatile compounds were identified from the pulp of ‘Kesington Pride’ mango; however, only 73 volatile compounds were present in notable amount. The most abundant group of volatile compounds was monoterpenes, accounting for abaout 44% of the total identified compounds, followed by sesquiterpenes (19%, aldehydes (11%,esters (10% aromatics (8%, alcohol (2%, ketones (2%, alkanes (1% and norisoprenoid (1%. -Terpinolene was the major compound during ripening. Except for -pinene, 3,7-dimethl-1,3,7-octatriene, 4-methl-1 (1-methylethylidene-cyclohexene, p-mentha-1,5,8-triene, aloocimene, the concentration of all other monoterpenes increased for the first six or eight days and decreased afterwards. All sesquiteroenes, p-cymene, p-cymen-9-ol,2-ethyl-1,4-dimethl benzene also increased during ripening and peaked on day four, six or eight of ripening. Ketones, aldehydes alkane and cis-3-hexenol, on the other hand, decreased during ripening. Ethanol, esters and norisoprenoid increased quite sharply at the end of ripening period.

  11. Extraction of organic compounds with room temperature ionic liquids.

    Science.gov (United States)

    Poole, Colin F; Poole, Salwa K

    2010-04-16

    Room temperature ionic liquids are novel solvents with a rather specific blend of physical and solution properties that makes them of interest for applications in separation science. They are good solvents for a wide range of compounds in which they behave as polar solvents. Their physical properties of note that distinguish them from conventional organic solvents are a negligible vapor pressure, high thermal stability, and relatively high viscosity. They can form biphasic systems with water or low polarity organic solvents and gases suitable for use in liquid-liquid and gas-liquid partition systems. An analysis of partition coefficients for varied compounds in these systems allows characterization of solvent selectivity using the solvation parameter model, which together with spectroscopic studies of solvent effects on probe substances, results in a detailed picture of solvent behavior. These studies indicate that the solution properties of ionic liquids are similar to those of polar organic solvents. Practical applications of ionic liquids in sample preparation include extractive distillation, aqueous biphasic systems, liquid-liquid extraction, liquid-phase microextraction, supported liquid membrane extraction, matrix solvents for headspace analysis, and micellar extraction. The specific advantages and limitations of ionic liquids in these studies is discussed with a view to defining future uses and the need not to neglect the identification of new room temperature ionic liquids with physical and solution properties tailored to the needs of specific sample preparation techniques. The defining feature of the special nature of ionic liquids is not their solution or physical properties viewed separately but their unique combinations when taken together compared with traditional organic solvents.

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

    Science.gov (United States)

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

    2013-10-01

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

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

    Science.gov (United States)

    Boczkaj, Grzegorz; Przyjazny, Andrzej; Kamiński, Marian

    2014-07-01

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

  14. Microorganisms Associated with Volatile Organic Compound Production in Spoilt Mango Fruits

    Directory of Open Access Journals (Sweden)

    Aliyu D. Ibrahim

    2015-11-01

    Full Text Available Microorganisms associated with the production of volatile compound in spoilt mango fruits sold in Sokoto town were isolated and identified. The organisms include seven species of bacteria and a species of yeast. These include Bacillus pumilus, Bacillus firmus, Brevibacillus laterosporus, Morganella morganii, Paenibacillus alvei, Staphylococcus saccharolyticus, Listeria monocytogenes and Candida krusei respectively. GC-MS analysis revealed the presence of eleven and sixteen volatile organic compound in the healthy and spoilt ripe mango fruits. Octadecanoic acid, oleic acid, 1 – Butanol, 3 – methyl-, carbonate (2:1 and 3,7 – Dimethyl nonane were common to both healthy and spoilt fruits with the first three having higher concentration in healthy fruits than spoilt while the later had higher concentration in the spoilt. One methyl group of 3,3- Dimethyl hexane in healthy fruit was shifted to position two to yield 2,3-Dimethyl hexane in the spoilt fruits. 2,2-Dimethylbutane, Methyl(methyl-4-deoxy-2,3-di-O-methyl.beta.1-threo-hex-4-enopyranosid urinate, 3-(4-amino-phenyl-2-(toluene-4-sulfonylamino-propionic acid, 2-Methyl-3-heptanone, 3,5-Nonadien-7-yn-2-ol, (E,E, Butanoic acid, 1,1-dimethylethyl ester, 1-methyl-3-beta.phenylethyl-2,4,5-trioxoimidazolidine, Pentanoic acid, 2,2-dimethyl, ethyl ester (Vinyl 2,2-dimethylpentanoate, 4-Methyurazole, 1-Tridecyn- 4 – 9 – ol, 1-Hexyl-1-nitrocyclohexane were unique to spoilt fruits. This study suggests that these unique volatile metabolites could be exploited as biomarkers to discriminate pathogens even when more than one disease is present thereby curbing post harvest loss during storage after further validation and the volatile organic compound could form the basis for constructing a metabolomics database for Nigeria.

  15. The contribution of evaporative emissions from gasoline vehicles to the volatile organic compound inventory in Mexico City.

    Science.gov (United States)

    Schifter, I; Díaz, L; Rodríguez, R; González-Macías, C

    2014-06-01

    The strategy for decreasing volatile organic compound emissions in Mexico has been focused much more on tailpipe emissions than on evaporative emissions, so there is very little information on the contribution of evaporative emissions to the total volatile organic compound inventory. We examined the magnitudes of exhaust and evaporative volatile organic compound emissions, and the species emitted, in a representative fleet of light-duty gasoline vehicles in the Metropolitan Area of Mexico City. The US "FTP-75" test protocol was used to estimate volatile organic compound emissions associated with diurnal evaporative losses, and when the engine is started and a journey begins. The amount and nature of the volatile organic compounds emitted under these conditions have not previously been accounted in the official inventory of the area. Evaporative emissions from light-duty vehicles in the Metropolitan Area of Mexico City were estimated to be 39 % of the total annual amount of hydrocarbons emitted. Vehicles built before 1992 (16 % of the fleet) were found to be responsible for 43 % of the total hydrocarbon emissions from exhausts and 31 % of the evaporative emissions of organic compounds. The relatively high amounts of volatile organic compounds emitted from older vehicles found in this study show that strong emission controls need to be implemented in order to decrease the contribution of evaporative emissions of this fraction of the fleet.

  16. Bacterial succession and the dynamics of volatile compounds during the fermentation of Chinese rice wine from Shaoxing region.

    Science.gov (United States)

    Liu, Shuang Ping; Mao, Jian; Liu, Yun Ya; Meng, Xiang Yong; Ji, Zhong Wei; Zhou, Zhi Lei; Ai-lati, Aisikaer

    2015-12-01

    Shaoxing rice wine is one of the most typical representatives of Chinese rice wine. It is brewed under non-sterile condition with various microorganism growing at the same time and forms a special flavor. The aims of this study was to monitor the bacterial succession by MiSeq pyrosequencing and the volatile compound dynamics by HS-SPME/GC–MS during brewing process. Moreover, the volatile compounds and bacterial community were analyzed by partial least squares regression to evaluate the effect of bacteria on volatile compounds formation. The results showed that there were ten dominating genera during Shaoxing rice wine fermentation process. Ten genera, Bacillus, Leuconostoc, Lactococcus, Weissella, Thermoactinomyces, Pseudomonas, Saccharopolyspora, Staphylococcus, Enterobacter and Lactobacillus, were identified as the main bacteria. The Bacillus and Lactobacillus dominated the Chinese rice wine ecosystems. In addition, a total of 64 volatile compounds were identified, mainly esters, alcohols, carbonyl compound and phenols. Pseudomonas were involved in synthesis of a wide variety of volatile compounds. Thermoactinomyces, Bacillus and Lactococcus also played critical roles in the formation of volatile compounds.

  17. 77 FR 16981 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of a Group of Four...

    Science.gov (United States)

    2012-03-23

    ... AGENCY 40 CFR Part 51 RIN 2060-AO17 Air Quality: Revision to Definition of Volatile Organic Compounds... organic compounds (VOCs) for purposes of preparing State Implementation Plans (SIPs) to attain the... VOCs that can be released into the atmosphere. VOCs are those organic compounds of carbon which...

  18. A fast and simple method for quantitative determination of fat-derived medium and low-volatile compounds in cheese

    NARCIS (Netherlands)

    Alewijn, M.; Sliwinski, E.L.; Wouters, J.T.M.

    2003-01-01

    Cheese flavour is a mixture of many (volatile) compounds, mostly formed during ripening. The current method was developed to qualify and quantify fat-derived compounds in cheese. Cheese samples were extracted with acetonitrile, which led to a concentrated solution of potential favour compounds, main

  19. Volatile organic compounds of Thai honeys produced from several floral sources by different honey bee species.

    Science.gov (United States)

    Pattamayutanon, Praetinee; Angeli, Sergio; Thakeow, Prodpran; Abraham, John; Disayathanoowat, Terd; Chantawannakul, Panuwan

    2017-01-01

    The volatile organic compounds (VOCs) of four monofloral and one multifloral of Thai honeys produced by Apis cerana, Apis dorsata and Apis mellifera were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography and mass spectrometry (GC-MS). The floral sources were longan, sunflower, coffee, wild flowers (wild) and lychee. Honey originating from longan had more VOCs than all other floral sources. Sunflower honey had the least numbers of VOCs. cis-Linalool oxide, trans-linalool oxide, ho-trienol, and furan-2,5-dicarbaldehyde were present in all the honeys studied, independent of their floral origin. Interestingly, 2-phenylacetaldehyde was detected in all honey sample except longan honey produced by A. cerana. Thirty-two VOCs were identified as possible floral markers. After validating differences in honey volatiles from different floral sources and honeybee species, the results suggest that differences in quality and quantity of honey volatiles are influenced by both floral source and honeybee species. The group of honey volatiles detected from A. cerana was completely different from those of A. mellifera and A. dorsata. VOCs could therefore be applied as chemical markers of honeys and may reflect preferences of shared floral sources amongst different honeybee species.

  20. Thermogenic respiratory processes drive the exponential increase of volatile organic compound emissions in Macrozamia cycad cones.

    Science.gov (United States)

    Terry, L Irene; Roemer, Robert B; Booth, David T; Moore, Chris J; Walter, Gimme H

    2016-07-01

    An important outcome of plant thermogenesis is increased emissions of volatiles that mediate pollinator behaviour. We investigated whether the large increase in emissions, mainly the monoterpene ß-myrcene (>90%), during daily thermogenic events of Macrozamia macleayi and lucida cycad cones are due solely to the influence of high cone temperatures or are, instead, a result of increased respiratory rates during thermogenesis. We concurrently measured temperature, oxygen consumption and ß-myrcene emission profiles during thermogenesis of pollen cones under typical environmental temperatures and during experimental manipulations of cone temperatures and aerobic conditions, all in the dark. The exponential rise in ß-myrcene emissions never occurred without a prior, large increase in respiration, whereas an increase in cone temperature alone did not increase emissions. When respiration during thermogenesis was interrupted by anoxic conditions, ß-myrcene emissions decreased. The increased emission rates are not a result of increased cone temperature per se (through increased enzyme activity or volatilization of stored volatiles) but are dependent on biosynthetic pathways associated with increased respiration during thermogenesis that provide the carbon, energy (ATP) and reducing compounds (NADPH) required for ß-myrcene production through the methylerythritol phosphate (MEP) pathway. These findings establish the significant contribution of respiration to volatile production during thermogenesis.

  1. Volatile organic compounds of Thai honeys produced from several floral sources by different honey bee species

    Science.gov (United States)

    Pattamayutanon, Praetinee; Angeli, Sergio; Thakeow, Prodpran; Abraham, John; Disayathanoowat, Terd; Chantawannakul, Panuwan

    2017-01-01

    The volatile organic compounds (VOCs) of four monofloral and one multifloral of Thai honeys produced by Apis cerana, Apis dorsata and Apis mellifera were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography and mass spectrometry (GC-MS). The floral sources were longan, sunflower, coffee, wild flowers (wild) and lychee. Honey originating from longan had more VOCs than all other floral sources. Sunflower honey had the least numbers of VOCs. cis-Linalool oxide, trans-linalool oxide, ho-trienol, and furan-2,5-dicarbaldehyde were present in all the honeys studied, independent of their floral origin. Interestingly, 2-phenylacetaldehyde was detected in all honey sample except longan honey produced by A. cerana. Thirty-two VOCs were identified as possible floral markers. After validating differences in honey volatiles from different floral sources and honeybee species, the results suggest that differences in quality and quantity of honey volatiles are influenced by both floral source and honeybee species. The group of honey volatiles detected from A. cerana was completely different from those of A. mellifera and A. dorsata. VOCs could therefore be applied as chemical markers of honeys and may reflect preferences of shared floral sources amongst different honeybee species. PMID:28192487

  2. Identification of volatile compounds in codfish ( Gadus) by a combination of two extraction Methods coupled with GC-MS analysis

    Science.gov (United States)

    Chang, Yufei; Hou, Hu; Li, Bafang

    2016-06-01

    Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the volatile compounds in codfish, a combination of solid phase micro-extraction (SPME) method and simultaneous distillation extraction (SDE) method was used to extract the volatiles. Gas chromatography-mass spectrometry (GC-MS) along with Kovats indices (KI) and authentic standard compounds were used to identify the volatiles. The results showed that a total of 86 volatile compounds were identified in codfish, of them 24 were extracted by SDE, 69 compounds by SPME, and 10 compounds by both SDE and SPME. Seventy volatile compounds were found to have specific odors, of them 7 typical compounds contributed significantly to the flavor of codfish. Alcohols ( i.e., (E)-2-penten-1-ol and 2-octanol), esters ( i.e., ethyl butyrate and methyl geranate), aldehydes ( i.e., 2-dodecenal and pentadecanal) contributed the most to fresh flavor while nitrogen compounds, sulphur compounds, furans, as well as some ketones ( i.e., 2-hydroxy-3-pentanone) brought unpleasant odor, such as fishy and earthy odor. It was indicated that the combination of multiple extraction methods and GC-MS analysis can enhance the accuracy of identification, and provide a reference for the further study on flavor of aquatic products.

  3. Comprehensive verification of new method "Ethanol as Internal Standard" for determination of volatile compounds in alcohol products by gas chromatography

    CERN Document Server

    Charapitsa, Siarhei V; Markovsky, Mikhail G; Yakuba, Yurii F; Kotov, Yurii N

    2014-01-01

    Recently proposed new method "Ethanol as Internal Standard" for determination of volatile compounds in alcohol products by gas chromatography is investigated from different sides. Results of experimental study from three different laboratories from Belarus and Russian Federation are presented.

  4. Datasets used in the manuscript titled "Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms and organic aerosol"

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset documents that all of the data used in the manuscript "Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic...

  5. Influence of volatile organic compounds of varnish-and-paint materials on the workers organism on the industrial enterprises

    Directory of Open Access Journals (Sweden)

    Г.І. Архіпова

    2010-02-01

    Full Text Available In article describes the reasons of air contamination in working area of endustrial enterprises, defines main ways of incoming and mechanism of action of volatile organic compounds of paintwork material on the organisms of workers.

  6. Dynamic Solution Injection: a new method for preparing pptv-ppbv standard atmospheres of volatile organic compounds

    Directory of Open Access Journals (Sweden)

    K. J. Jardine

    2010-07-01

    Full Text Available Proton Transfer Reaction-Mass Spectrometry (PTR-MS and thermal desorption Gas Chromatography-Mass Spectrometry (GC-MS allow for absolute quantification of a wide range of atmospheric volatile organic compounds (VOCs with concentrations in the ppbv to pptv range. Although often neglected, routine calibration is necessary for accurate quantification of VOCs by PTR-MS and GC-MS. Several gas calibration methods currently exist, including compressed gas cylinders, permeation tubes, diffusion tubes, and liquid injection. While each method has its advantages and limitations, no single technique has emerged that is capable of dynamically generating accurate concentrations of complex mixtures of VOCs over a large concentration range (ppbv to pptv, is technically simple and field portable, and affordable. We present the development of a new VOC calibration technique based on liquid injection with these features termed Dynamic Solution Injection (DSI. This method consists of injecting VOCs (0.1–0.5 mM dissolved in cyclohexane (PTR-MS or methanol (GC-MS into a 1.0 slpm flow of purified dilution gas in an unheated 25 mL glass vial. Upon changes in the injection flow rate (0.5–4.0 μL min−1, new VOC concentrations are reached within seconds to minutes, depending on the compound, with a liquid injection flow rate accuracy and precision of better than 7% and 4%, respectively. We demonstrate the utility of the DSI technique by calibrating a PTR-MS to seven different cyclohexane solutions containing a total of 34 different biogenic compounds including volatile isoprenoids, oxygenated VOCs, fatty acid oxidation products, aromatics, and dimethyl sulfide. In order to validate the new DSI method, a GC-MS and PTR-MS calibration intercomparison with VOC standards generated by dynamic dilution of NIST traceable permeation tubes (α-pinene, acetone, and ethanol and a compressed gas cylinder (acetaldehyde was made. The results revealed that while

  7. Group extraction of organic compounds present in liquid samples

    Science.gov (United States)

    Jahnsen, Vilhelm J. (Inventor)

    1976-01-01

    An extraction device is disclosed comprising a tube containing a substantially inert, chemically non-reactive packing material with a large surface area to volume ratio. A sample which consists of organic compounds dissolved in a liquid, is introduced into the tube. As the sample passes through the packing material it spreads over the material's large surface area to form a thin liquid film which is held on the packing material in a stationary state. A particular group or family of compounds is extractable from the sample by passing a particular solvent system consisting of a solvent and selected reagents through the packing material. The reagents cause optimum conditions to exist for the compounds of the particular family to pass through the phase boundary between the sample liquid and the solvent of the solvent system. Thus, the compounds of the particular family are separated from the sample liquid and become dissolved in the solvent of the solvent system. The particular family of compounds dissolved in the solvent, representing an extract, exits the tube together with the solvent through the tube's nozzle, while the rest of the sample remains on the packing material in a stationary state. Subsequently, a different solvent system may be passed through the packing material to extract another family of compounds from the remaining sample on the packing material.

  8. Soil Samplers: New Techniques for Subsurface Sampling for Volatile Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Susan Sorini; John Schabron; Joseph Rovani; Mark Sanderson

    2009-03-31

    Soil sampling techniques for volatile organic analysis must be designed to minimize loss of volatile organic compounds (VOCs) from the soil that is being sampled. Preventing VOC loss from soil cores that are collected from the subsurface and brought to the surface for subsampling is often difficult. Subsurface bulk sample retrieval systems are designed to obtain intact cylindrical cores of soil ranging anywhere from one to four inches in diameter, and one to several feet in length. The current technique that is used to subsample these soil cores for VOC analysis is to expose a horizontal section of the soil core to the atmosphere; screen the exposed soil using a photoionization detector (PID) or other appropriate device to locate contamination in the soil core; and use a hand-operated coring tool to collect samples from the exposed soil for analysis. Because the soil core can be exposed to the atmosphere for a considerable length of time during screening and sample collection, the current sub-sampling technique provides opportunity for VOCs to be lost from the soil. This report describes three alternative techniques from the current technique for screening and collecting soil samples from subsurface soil cores for VOC analysis and field testing that has been done to evaluate the techniques. Based on the results of the field testing, ASTM D4547, Standard Guide for Sampling Waste and Soils for Volatile Organic Compounds, was revised to include information about the new techniques.

  9. A mass transfer model for predicting emission of the volatile organic compounds in wet building materials

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tao; JIA Li

    2008-01-01

    A new mass transfer model is developped to predict the volatile organic compounds (VOCs) from fresh wet building materials. The dry section of wet materials during the process of VOC emission from wet building materials is considered in this new model, differing from the mass transfer-based models in other literatures. The mechanism of effect of saturated vapor pressure on the surface of wet building materials in the process of VOC emission is discussed. The concentration of total volatile organic compounds (TVOC) in the building materials gradually decreases as the emission of VOCs begins, and the vapor pressure of VOCs on the surface of wet building materials decreases in the case of newly wet building materials. To ensure the partial pressure of VOCs on the surface of wet building materials to be saturated vapor pressure, the interface of gas-wet layer is lowered, and a dry layer of no-volatile gases in the material is formed. Compared with the results obtained by VB model, CFD model and the ex-periment data, the results obtained by the present model agree well with the results obtained by CFD model and the experiment data. The present model is more accurate in predicting emission of VOC from wet building materials than VB model.

  10. Simultaneous distillation-extraction of high-value volatile compounds from Cistus ladanifer L.

    Science.gov (United States)

    Teixeira, Salomé; Mendes, Adélio; Alves, Arminda; Santos, Lúcia

    2007-02-19

    The present paper describes a procedure to isolate volatiles from rock-rose (Cistus ladanifer L.) using simultaneous distillation-extraction (SDE). High-value volatile compounds (HVVC) were selected and the influence of the extraction conditions investigated. The effect of the solvent nature and extraction time on SDE efficiency was studied. The best performance was achieved with pentane in 1 h operation. The extraction efficiencies ranged from 65% to 85% and the repeatability varied between 4% and 6% (as a CV%). The C. ladanifer SDE extracts were analysed by headspace solid phase microextraction (HS-SPME) followed by gas chromatography with flame ionization detection (GC-FID). The HS-SPME sampling conditions such as fiber coating, temperature, ionic strength and exposure time were optimized. The best results were achieved with an 85 microm polyacrylate fiber for a 60 min headspace extraction at 40 degrees C with 20% (w/v) of NaCl. For optimized conditions the recovery was in average higher than 90% for all compounds and the intermediate precision ranged from 4 to 9% (as CV %). The volatiles alpha-pinene (22.2 mg g(-1) of extract), 2,2,6-trimethylcyclohexanone (6.1 mg g(-1) of extract), borneol (3.0 mg g(-1) of extract) and bornyl acetate (3.9 mg g(-1) of extract) were identified in the SDE extracts obtained from the fresh plant material.

  11. VISTA: A μ-Thermogravimeter for Investigation of Volatile Compounds in Planetary Environments

    Science.gov (United States)

    Palomba, Ernesto; Longobardo, Andrea; Dirri, Fabrizio; Zampetti, Emiliano; Biondi, David; Saggin, Bortolino; Bearzotti, Andrea; Macagnano, Antonella

    2016-06-01

    This paper presents the VISTA (Volatile In Situ Thermogravimetry Analyser) instrument, conceived to perform planetary in-situ measurements. VISTA can detect and quantify the presence of volatile compounds of astrobiological interest, such as water and organics, in planetary samples. These measurements can be particularly relevant when performed on primitive asteroids or comets, or on targets of potential astrobiological interest such as Mars or Jupiter's satellite Europa. VISTA is based on a micro-thermogravimetry technique, widely used in different environments to study absorption and sublimation processes. The instrument core is a piezoelectric crystal microbalance, whose frequency variations are affected by variations of the mass of the deposited sample, due to chemical processes such as sublimation, condensation or absorption/desorption. The low mass (i.e. 40 g), the low volume (less than 10 cm3) and the low power (less than 1 W) required makes this kind of instrument very suitable for space missions. This paper discusses the planetary applications of VISTA, and shows the calibration operations performed on the breadboard, as well as the performance tests which demonstrate the capability of the breadboard to characterize volatile compounds of planetary interests.

  12. Analysis of volatile organic compounds in compost samples: A potential tool to determine appropriate composting time.

    Science.gov (United States)

    Zhu, Fengxiang; Pan, Zaifa; Hong, Chunlai; Wang, Weiping; Chen, Xiaoyang; Xue, Zhiyong; Yao, Yanlai

    2016-12-01

    Changes in volatile organic compound contents in compost samples during pig manure composting were studied using a headspace, solid-phase micro-extraction method (HS-SPME) followed by gas chromatography with mass spectrometric detection (GC/MS). Parameters affecting the SPME procedure were optimized as follows: the coating was carbon molecular sieve/polydimethylsiloxane (CAR/PDMS) fiber, the temperature was 60°C and the time was 30min. Under these conditions, 87 compounds were identified from 17 composting samples. Most of the volatile components could only be detected before day 22. However, benzenes, alkanes and alkenes increased and eventually stabilized after day 22. Phenol and acid substances, which are important factors for compost quality, were almost undetectable on day 39 in natural compost (NC) samples and on day 13 in maggot-treated compost (MC) samples. Our results indicate that the approach can be effectively used to determine the composting times by analysis of volatile substances in compost samples. An appropriate composting time not only ensures the quality of compost and reduces the loss of composting material but also reduces the generation of hazardous substances. The appropriate composting times for MC and NC were approximately 22days and 40days, respectively, during the summer in Zhejiang.

  13. Non-conventional gas phase remediation of volatile halogenated compounds by dehydrated bacteria.

    Science.gov (United States)

    Erable, Benjamin; Goubet, Isabelle; Seltana, Amira; Maugard, Thierry

    2009-06-01

    Traditional biological removal processes are limited by the low solubility of halogenated compounds in aqueous media. A new technology appears very suitable for the remediation of these volatile organic compounds (VOCs). Solid/gas bio-catalysis applied in VOC remediation can transform halogenated compounds directly in the gas phase using dehydrated cells as a bio-catalyst. The hydrolysis of volatile halogenated substrates into the corresponding alcohol was studied in a solid/gas biofilter where lyophilised bacterial cultures were used as the catalyst. Four strains containing dehalogenase enzymes were tested for the hydrolysis of 1-chlorobutane. The highest removal yield was obtained using the dhaA-containing strains, the maximal reaction rate of 0.8 micromol min(-1)g(-1) being observed with Escherichia coli BL21(DE3)(dhaA). Various treatments such as cell disruption by lysozyme or alkaline gas addition in the bio-filter could stabilise the dehalogenase activity of the bacteria. A pre-treatment of the dehydrated bacterial cells by ammonia vapour improved the stability of the catalyst and a removal activity of 0.9 micromol min(-1)g(-1) was then obtained for 60h. Finally, the process was extended to a range of halogenated substrates including bromo- and chloro-substrates. It was shown that the removal capacity for long halogenated compounds (C(5)-C(6)) was greatly increased relative to traditional biological processes.

  14. Concentrations of volatile organic compounds at a building with health and comfort complaints.

    Science.gov (United States)

    Weschler, C J; Shields, H C; Rainer, D

    1990-05-01

    For four separate periods over a 1-yr span, the concentrations of volatile organic compounds (VOCs) have been measured at a facility with a history of occupant complaints. The reported symptoms were characteristic of "sick building syndrome." This study was initiated to determine if VOC levels were higher than those measured in "complaint-free" buildings and, if so, to identify sources and other factors that might contribute to the elevated concentrations. VOCs were collected with passive samplers, using a sampling interval that lasted from 3 to 4 weeks. Following collection, the samplers were extracted, and the compounds in the extract were separated and identified using standard gas chromatographic-mass spectrometric procedures. Over 40 different organic compounds with concentrations in excess of 1 microgram/m3 were identified; several species had values greater than 100 micrograms/m3. For each of the first three sampling periods, the total concentration of VOCs detected using this methodology was in excess of 3 mg/m3. Sources of the identified compounds included cleaning products, floor wax, latex paints, and reentrained motor vehicle exhaust. However, the dominant source was the hydraulic system for the buildings' elevators. Compounds were volatilizing from the hydraulic fluid used in this system. Neither the elevator shafts nor the mechanical room housing the fluid reservoirs were vented to the outside. The problem was compounded by the relatively small amount of outside air used for ventilation at this facility (less than 6 L/sec [12 cfm]/occupant or about 1/4 air change/hr). At such low ventilation rates, compounds with strong sources can achieve high steady-state concentrations within the facility. Recommendations have been made to reduce the VOC levels at this site. Although implementing the recommendations will be costly, even a slight improvement in employee productivity will offset these costs.

  15. Influence of the addition of activated charcoal on the absorption of volatile organic compounds in water; Influence de l'ajout de charbon actif sur l'absorption dans l'eau de composes organiques volatils

    Energy Technology Data Exchange (ETDEWEB)

    Dubray, A.; Thomas, D.; Vanderschuren, J. [Faculte Polytechnique de Mons, Service de Genie Chimique et Biochimique, Mons (Belgium)

    2001-07-01

    A new technique of abatement of volatile organic compounds (VOC) has been developed by combining two classical physico-chemical processes: the absorption and the adsorption. The capture of isopropanol and acetone with concentrations of 1 to 5 g/m{sup 3} of air has been performed using aqueous suspensions with up to 10% of weight of activated charcoal content, in a cable contactor operating semi-continuously with a recirculation of the suspension. A modeling of the mass transfer phenomena occurring during these tests has permitted to demonstrate the effect of charcoal concentration on the global process and on the gas-liquid transfer. (J.S.)

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

    Science.gov (United States)

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

    2016-06-01

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

  17. Assessment of volatile organic compounds in surface water at Canal Creek, Aberdeen Proving Ground, Maryland, November 1999-September 2000

    Science.gov (United States)

    Phelan, Daniel J.; Olsen, Lisa D.; Senus, Michael P.; Spencer, Tracey A.

    2001-01-01

    The purpose of this report is to describe the occurrence and distribution of volatile organic compounds in surface-water samples collected by the U.S. Geological Survey in the Canal Creek area of Aberdeen Proving Ground, Maryland, from November 1999 through September 2000. The report describes the differences between years with below normal and normal precipitation, the effects of seasons, tide stages, and location on volatile organic compound concentrations in surface water, and provides estimates of volatile organic concentration loads to the tidal Gunpowder River. Eighty-four environmental samples from 20 surface-water sites were analyzed. As many as 13 different volatile organic compounds were detected in the samples. Concentrations of volatile organic compounds in surface-water samples ranged from below the reporting limit of 0.5 micrograms per liter to a maximum of 50.2 micrograms per liter for chloroform. Chloroform was detected most frequently, and was found in 55 percent of the environmental samples that were analyzed for volatile organic compounds (46 of 84 samples). Carbon tetrachloride was detected in 56 percent of the surface-water samples in the tidal part of the creek (34 of 61 samples), but was only detected in 3 of 23 samples in the nontidal part of the creek. 1,1,2,2-Tetrachloroethane was detected in 43 percent of the tidal samples (26 of 61 samples), but was detected at only two nontidal sites and only during November 1999. Three samples were collected from the tidal Gunpowder River about 300 feet from the mouth of Canal Creek in May 2000, and none of the samples contained volatile organic compound concentrations above detection levels. Volatile organic compound concentrations in surface water were highest in the reaches of the creek adjacent to the areas with the highest known levels of ground-water contamination. The load of total volatile organic compounds from Canal Creek to the Gunpowder River is approximately 1.85 pounds per day (0

  18. Measurement of surface emission flux rates for volatile organic compounds at Technical Area 54

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo, V.; Morgenstern, M.; Krier, D. [Los Alamos National Lab., NM (United States); Gilkeson, R. [Weirich and Associates, Albuquerque, NM (United States)

    1998-06-01

    The survey described in this report was conducted to estimate the mass of volatile organic compounds venting to the atmosphere from active and inactive waste disposal sites at Technical Area 54. A large number of nonintrusive passive sample collection devices were placed on the ground surface for 72 hours to characterize an area of approximately 150 acres. Results provided an indication of the boundary location of the known volatile organic plume, plume constituents, and isolated high concentration areas. The data from this survey enhanced existing data from a limited number of monitor wells currently used for plume surveillance. Results indicate that the estimated mass emission to the atmosphere is orders of magnitude lower than what is considered a small flux rate at a spill site or a Resource Conservation and Recovery Act landfill and is far below the threshold limit established by the State of New Mexico as an air quality concern.

  19. MEMBRANE SYSTEM FOR RECOVERY OF VOLATILE ORGANIC COMPOUNDS FROM REMEDIATION OFF-GASES

    Energy Technology Data Exchange (ETDEWEB)

    J.G. Wijmans

    2003-11-17

    In situ vacuum extraction, air or steam sparging, and vitrification are widely used to remediate soil contaminated with volatile organic compounds (VOCs). All of these processes produce a VOC-laden air stream from which the VOC must be removed before the air can be discharged or recycled to the generating process. Treatment of these off-gases is often a major portion of the cost of the remediation project. Currently, carbon adsorption and catalytic incineration are the most common methods of treating these gas streams. Membrane Technology and Research, Inc. (MTR) proposed an alternative treatment technology based on selective membranes that separate the organic components from the gas stream, producing a VOC-free air stream. This technology can be applied to off-gases produced by various remediation activities and the systems can be skid-mounted and automated for easy transportation and unattended operation. The target performance for the membrane systems is to produce clean air (less than 10 ppmv VOC) for discharge or recycle, dischargeable water (less than 1 ppmw VOC), and a concentrated liquid VOC phase. This report contains the results obtained during Phase II of a two-phase project. In Phase I, laboratory experiments were carried out to demonstrate the feasibility of the proposed approach. In the subsequent Phase II project, a demonstration system was built and operated at the McClellan Air Force Base near Sacramento, California. The membrane system was fed with off-gas from a Soil Vacuum Extraction (SVE) system. The work performed in Phase II demonstrated that the membrane system can reduce the VOC concentration in remediation off-gas to 10 ppmv, while producing a concentrated VOC phase and dischargeable water containing less than 1 ppmw VOC. However, the tests showed that the presence of 1 to 3% carbon dioxide in the SVE off-gas reduced the treatment capacity of the system by a factor of three to four. In an economic analysis, treatment costs of the membrane

  20. Potential atmospheric production of small volatile organic compounds from soot oxidation

    Science.gov (United States)

    Horn, A.; Carpenter, L.; Daly, H.; Jones, C.

    2003-04-01

    In the polluted troposphere, VOCs are involved in a range of interlinked chemical and photochemical cycles with a direct bearing on the production of ozone. The rates of emission, production and reaction of VOC are therefore an important component of atmospheric models. Recent urban measurements using 2D-GC methods show that there are a large number of unidentified and unattributed VOC components. Any new sources of such material with high photochemical ozone creation potentials may therefore be significant. Hydrocarbon, fossil fuel and biomass burning produces particulate carbonaceous aerosols (soot) in addition to gas phase products. Soot in the atmosphere is known to undergo oxidation becoming hydrophilic in aged urban plumes and the process is also known to produce water soluble organic compounds. In our experiments, soot samples are prepared by combustion of appropriate liquid hydrocarbons and reacted with ozone in a glass reaction vessel. Analysis of the surface and gas-phase during the course of this reaction confirms kinetic measurements showing irreversible uptake of O_3 on soot and further identify that the reaction has oxidised the surface. Transmission electron micrographs of the fresh and ozonised soot reveal small, coagulated particles: fresh soot particle size ranges from 50--90 nm which reduces to 40--50 nm after ozonolysis. Separation of the soluble components of fresh and ozonised soot samples analysed by GC/MS reveal the presence of polyaromatic and unsaturated components in unreacted soot and partially oxidised components post-ozonolysis. ATR-IR spectra of soot extracts and ozonised soot confirm that surface features due to the creation of oxidised surface products grow in with exposure time. These include carbonyl, ester and alcohol functional groups. Direct sampling of the gas-phase during the ozone reaction allows some gaseous products to be identified as small organic acids, ketones and alcohols. Overall, the reaction of ozone with soot

  1. Characterization of urinary volatiles in Swiss male mice (Mus musculus): bioassay of identified compounds

    Indian Academy of Sciences (India)

    S Achiraman; G Archunan

    2002-12-01

    The present study was carried out to investigate the chemical nature of the urine of male mice and to assess its bioactivity. Urine of mature male mice was extracted with dichloromethane (1 : 1 ratio v/v) and analysed by gas-chromatography linked mass-spectrometry (GC-MS). Ten different compounds such as alkanes, alcohols, etc. were detected in the urine. Among the ten, five compounds are specific to males, namely 3-cyclohexene-1-methanol (I), 3-amino-s-triazole (II), 4-ethyl phenol (III), 3-ethyl-2,7-dimethyl octane (IV) and 1-iodoundecane (V). The compound, 4-ethylphenol, has been previously reported in several strains of male mice. Furthermore, the compounds (II) and (IV) are similar to 2-sec-butylthiazole and dehydro-exo-brevicomin compounds which have already been reported in male mice. Bioassay revealed that compounds (II), (III) and (IV) were responsible for attracting females and in inducing aggression towards males, as compared to the other compounds, i.e. (I) and (V). The results indicate that these three volatiles (II, III and IV) of male mice appear to act as attractants of the opposite sex.

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

    Science.gov (United States)

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

    2005-10-19

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

  3. The Use of Amberlite Adsorbents for Green Chromatography Determination of Volatile Organic Compounds in Air

    Directory of Open Access Journals (Sweden)

    Luis Juan-Peiró

    2012-01-01

    Full Text Available Passive samplers have been widely used for volatile organic compounds determination. Following the green chemistry tendency of the direct determination of adsorbed compounds in membrane-based devices through using head space direct chromatography analysis, this work has evaluated the use of Amberlite XAD-2, XAD-4, and XAD-16 adsorbents as a filling material for passive samplers. Direct analysis of the membranes by HS-GC-MS involves a solvent-free method avoiding any sample treatment. For exposed membranes, recoveries ranged from 10% to 203%, depending on the compound and adsorbent used. The limit of the detection values ranged from 1 to 140 ng per sampler. Acceptable precision and sensitivity levels were obtained for the XAD resins assayed.

  4. Production of extremely low volatile organic compounds from biogenic emissions: Measured yields and atmospheric implications

    Energy Technology Data Exchange (ETDEWEB)

    Jokinen, Tuija; Berndt, Torsten; Makkonen, Risto; Kerminen, Veli-Matti; Junninen, Heikki; Paasonen, Pauli; Stratmann, Frank; Herrmann, Hartmut; Guenther, Alex B.; Worsnop, Douglas R.; Kulmala, M.; Ehn, Mikael K.; Sipila, Mikko

    2015-06-09

    Extremely low volatility organic compounds (ELVOC) are suggested to promote aerosol particle formation and cloud condensation nuclei (CCN) production in the atmosphere. We show that the capability of biogenic VOC (BVOC) to produce ELVOC depends strongly on their chemical structure and relative oxidant levels. BVOC with an endocyclic double bond, representative emissions from, e.g., boreal forests, efficiently produce ELVOC from ozonolysis. Compounds with exocyclic double bonds or acyclic compounds including isoprene, emission representative of the tropics, produce minor quantities of ELVOC, and the role of OH radical oxidation is relatively larger. Implementing these findings into a global modeling framework shows that detailed assessment of ELVOC production pathways is crucial for understanding biogenic secondary organic aerosol and atmospheric CCN formation.

  5. Off-season biogenic volatile organic compound emissions from heath mesocosms

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Gierth, Diana; Bilde, Merete;

    2013-01-01

    measured in growth chambers by an enclosure method using gas chromatography-mass spectrometry. CO2 exchange, soil microbial biomass and soil carbon and nitrogen concentrations were also analyzed. Vegetation cutting increased BVOC emissions by more than 20-fold, and the induced compounds were mainly eight-carbon......Biogenic volatile organic compounds (BVOCs) affect both atmospheric processes and ecological interactions. Our primary aim was to differentiate between BVOC emissions from above- and belowground plant parts and heath soil outside the growing season. The second aim was to assess emissions from...... compounds and sesquiterpenes. In the Deschampsia heath, the overall low BVOC emissions originated mainly from soil. In the mixed heath, root and soil emissions were negligible. Net BVOC emissions from roots and soil of these well-drained heaths do not significantly contribute to ecosystem emissions...

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

    Science.gov (United States)

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

    2016-05-01

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

  7. Compostos voláteis em méis florais Volatile compounds in floral honeys

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Bastos De Maria

    2003-01-01

    Full Text Available A review about origin, composition and importance of volatile compounds in floral honeys is presented. Hydrocarbons, aromatic components, acids, diacids, terpenoids, ketones, aldehydes, esters and alcohols have been found in honey aroma of different botanical origin. Cis-rose oxide has been proposed as an indicator for Tilia cordata honey. Citrus honeys are known to contain methyl anthranilate, a compound which other honeys virtually lack. Linalool, phenylethylalcohol, phenylacetaldehyde, p-anisaldehyde and benzaldehyde are important contributors for the aroma of different unifloral honeys. Both isovaleric acid, gama-decalactone and benzoic acid appears to be important odourants for Anarcadium occidentale and Croton sp. honeys from Brazil. The furfurylmercaptan, benzyl alcohol, delta-octalactone, eugenol, phenylethylalcohol and guaiacol appear to be only relevant compounds for Anarcadium occidentale. The vanillin was considered an important odourant only for Croton sp..

  8. Gas-Chromatographic Analysis of Major Volatile Compounds Found in Traditional Fruit Brandies from Transylvania, Romania

    Directory of Open Access Journals (Sweden)

    Teodora Emilia RUSU COLDEA

    2011-11-01

    Full Text Available In the current study, the major volatile compounds from three categories of traditional fruit brandies (plum, apple and pear were characterized by gas-chromatography (GC-FID. There were collected 26 samples from different locations of Transylvania (Romania, all made by traditional technologies involving fermentation in barrels and distillation in copper stills. The major volatile compounds, besides ethanol, identified and quantified were: acetaldehyde, ethyl acetate, methanol, 1-propanol, 2-butanol, iso-butylic alcohol, alcool amyl active, iso-amylic alcohol, 1-butanol and furfural. For each type of brandy, positive but no significant correlations between methanol and furfural concentrations in plum and apple brandy were noticed. To evaluate the differences in composition regarding the geographical origin of plum brandies and to analyze the composition of plum, apple and pear brandies it has been compared the mean values (MVP, MVA and MVPe obtained for each volatile. For plum brandies it has been observed differences among the mean values of each volatile, in samples originating from counties Cluj, Bistriţa-Năsăud and Maramureş. For methanol, acetaldehyde and 1-propanol the MVP Cluj values were significantly higher than MVP Bistriţa-Năsăud. For iso-butylic alcohol, amyl active alcohol, iso-amylic alcohol the MVP Cluj values were significantly higher than for Bistriţa-Năsăud and Maramureş, while for ethyl acetate and furfural the MVP Bistriţa-Năsăud were significantly higher than MVP Cluj and MVP Maramureş. When compared the mean values of volatiles in plum vs apple vs pear brandies, for ethyl acetate, methanol, 2-butanol, 1-propanol and 1-butanol, the MVPe values were significantly higher than MVA, for furfural, amyl active and iso-amylic alcohols, while for acetaldehyde the MVPe values were significantly higher than MVP. Methanol represented the major volatile component, characteristic to fruit brandies, released by enzymatic

  9. Phase partitioning and volatility of secondary organic aerosol components formed from α-pinene ozonolysis and OH oxidation: the importance of accretion products and other low volatility compounds

    Directory of Open Access Journals (Sweden)

    F. D. Lopez-Hilfiker

    2015-02-01

    Full Text Available We measured a large suite of gas and particle phase multi-functional organic compounds with a Filter Inlet for Gases and AEROsols (FIGAERO coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS developed at the University of Washington. The instrument was deployed on environmental simulation chambers to study monoterpene oxidation as a secondary organic aerosol (SOA source. We focus here on results from experiments utilizing an ionization method most selective towards acids (acetate negative ion proton transfer, but our conclusions are based on more general physical and chemical properties of the SOA. Hundreds of compounds were observed in both gas and particle phases, the latter being detected upon temperature programmed thermal desorption of collected particles. Particulate organic compounds detected by the FIGAERO HR-ToF-CIMS are highly correlated with, and explain at least 25–50% of, the organic aerosol mass measured by an Aerodyne Aerosol Mass Spectrometer (AMS. Reproducible multi-modal structures in the thermograms for individual compounds of a given elemental composition reveal a significant SOA mass contribution from large molecular weight organics and/or oligomers (i.e. multi-phase accretion reaction products. Approximately 50% of the HR-ToF-CIMS particle phase mass is associated with compounds having effective vapor pressures 4 or more orders of magnitude lower than commonly measured monoterpene oxidation products. The relative importance of these accretion-type and other extremely low volatility products appears to vary with photochemical conditions. We present a desorption temperature based framework for apportionment of thermogram signals into volatility bins. The volatility-based apportionment greatly improves agreement between measured and modeled gas–particle partitioning for select major and minor components of the SOA, consistent with thermal decomposition during desorption causing

  10. Solvent-based dissolution method to sample gas-phase volatile organic compounds for compound-specific isotope analysis.

    Science.gov (United States)

    Bouchard, Daniel; Hunkeler, Daniel

    2014-01-17

    An investigation was carried out to develop a simple and efficient method to collect vapour samples for compound specific isotope analysis (CSIA) by bubbling vapours through an organic solvent (methanol or ethanol). The compounds tested were benzene and trichloroethylene (TCE). The dissolution efficiency was tested for different air volume injections, using flow rates ranging from 25ml/min to 150ml/min and injection periods varying between 10 and 40min. Based on the results, complete mass recovery for benzene and TCE in both solvents was observed for the flow rates of 25 and 50ml/min. However, small mass loss was observed at increased flow rate. At 150ml/min, recovery was on average 80±17% for benzene and 84±10% for TCE, respectively in methanol and ethanol. The δ(13)C data measured for benzene and TCE dissolved in both solvents were reproducible and were stable independently of the volume of air injected (up to 6L) or the flow rate used. The stability of δ(13)C values hence underlines no isotopic fractionation due to compound-solvent interaction or mass loss. The development of a novel and simple field sampling technique undertaken in this study will facilitate the application of CSIA to diverse gas-phase volatile organic compound studies, such as atmospheric emissions, soil gas or vapour intrusion.

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

    Science.gov (United States)

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

    2015-03-01

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

  12. Lipid and cholesterol oxidation, color changes, and volatile compounds production in irradiated raw pork batters with different fat content

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Cheo Run; Byun, Myung Woo [KAERI, Taejon (Korea, Republic of)

    2000-05-01

    An emulsion-type product was prepared to determine the effect of irradiation on lipid and cholesterol oxidation, color change, and volatile production in raw pork with different fat content. Lipid oxidation increased with an increase in fat content or irradiation dose. Irradiated batters had higher cholesterol oxides than did non-irradiated batters, and the major cholesterol oxides formed in irradiated pork batters were 7{alpha}- and 7{beta}- hydroxycholesterol. Hunter color a- and b-values of raw pork batters were decreased by irradiation regardless of fat content. Irradiation significantly increased the amount of volatile compounds. Although lipid oxidation of high fat products (10 and 15% fat) was higher than that of low fat products (4%), high fat products did not always produce greater amount of volatile compounds in raw pork batters. In summary, irradiation increased lipid and cholesterol oxidation, and volatile compounds production, and had detrimental effects on the color of raw pork batter under aerobic conditions.

  13. Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Javad Golhosseini

    2015-06-01

    Full Text Available Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOC are considered as the main effective factors in causing air pollution. Vehicles are among the major sources which emit these compounds, so it seems that automobiles’ microenvironment is one of the places where people are exposed to high concentration of VOC. Evaluating the exposure amount of Total Volatile Organic Compounds (TVOC can indeed be used as an indicator to estimate the amount of exposure to every individual VOC. This study was conducted on the concentration of TVOC inside Tehran taxies for a period of one year. For this purpose, a real time instrument equipped with photo-ionization detector (PID was used. Consequently, the highest and the lowest measured TVOC in taxies equaled 3.33 ppm and 0.72 ppm, respectively. In addition, the arithmetic mean of TVOC concentration was 1.77±0.53 ppm inside the examined taxies. In this study, the parameters like measurement time, climate and vehicle conditions were found to have significant effect on the amount of exposure to TVOC.

  14. Determination of volatile compounds and quality parameters of traditional Istrian dry-cured ham.

    Science.gov (United States)

    Marušić, Nives; Vidaček, Sanja; Janči, Tibor; Petrak, Tomislav; Medić, Helga

    2014-04-01

    The aim of this work was to determine the characteristics of Istrian dry-cured ham by instrumental methods and sensory analysis. The aroma-active compounds of Istrian dry-cured ham from 2010 and 2012 were investigated by using headspace-solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics. 92 volatile aroma compounds of Istrian dry-cured ham were found. Volatile compounds belonged to several chemical groups: aldehydes (51.4; 51.3%), terpenes (16.5; 16.4%), alcohols (15.5; 13.2%), ketones (8.6; 7.4%), alkanes (3.8; 5.7%), esters (1.3; 1.6%), aromatic hydrocarbons (0.8; 3.9%) and acids (0.6; 0.9%). Principal component analysis (PCA) showed that fat content, tenderness and melting texture were positively correlated. Terpenes were strongly correlated with flavour of added spices. Sweet taste and the presence of esters were positively correlated as well as negative odour, raw meat flavour and water content.

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

    Science.gov (United States)

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

    2014-01-01

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

  16. Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Javad Golhosseini*

    2015-06-01

    Full Text Available Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOCs are considered as the main effective factors in causing air pollution. Vehicles are among the major sources which emit these compounds, so it seems that automobiles’ microenvironment is one of the places where people are exposed to high concentration of VOC. Evaluating the exposure amount of Total Volatile Organic Compounds (TVOC can indeed be used as an indicator to estimate the amount of exposure to every individual VOC. This study was conducted on the concentration of TVOC inside Tehran taxies for a period of one year. For this purpose, a real time instrument equipped with photo-ionization detector (PID was used. Consequently, the highest and the lowest measured TVOC in taxies equaled 3.33 ppm and 0.72 ppm, respectively. In addition, the arithmetic mean of TVOC concentration was 1.77±0.53 ppm inside the examined taxies. In this study, the parameters like measurement time, climate and vehicle conditions were found to have significant effect on the amount of exposure to TVOC.

  17. Quantifying Volatile Organic Compound Emissions from Solvents and their Impacts on Urban Air Quality

    Science.gov (United States)

    Mcdonald, B. C.; De Gouw, J. A.; Gilman, J.; Ahmadov, R.; Cappa, C. D.; Frost, G. J.; Goldstein, A. H.; Jathar, S.; Jimenez, J. L.; Kim, S. W.; McKeen, S. A.; Roberts, J. M.; Trainer, M.

    2016-12-01

    Solvents, which consist of personal care products, paints, degreasing agents, and other chemical products, are an important anthropogenic source of volatile organic compound (VOC) emissions. Yet there are many unresolved questions related to their emission rates, chemical composition, and relative importance on urban air quality problems. Using atmospheric measurements of speciated VOCs collected at a ground site located in the Los Angeles basin during the California Nexus (CalNex) Study in 2010, and utilizing data on the composition of solvent emissions from the California Air Resources Board (CARB), we are able to reconcile solvent emissions with ambient observations. Our analysis indicates that solvent emissions are underestimated by a factor of 2-3 in the CARB inventory. We then estimate the reactivity of solvent emissions with the hydroxyl (OH) radical, and also estimate the propensity of solvent emissions to form secondary organic aerosol (SOA). Solvents contain significant fractions of oxygenated compounds, including intermediate volatility compounds, which if released to the atmosphere are potentially reactive and can lead to the formation of SOA. Overall, our results suggest that in the Los Angeles basin, solvents are now the largest anthropogenic source of VOC emissions, OH reactivity, and SOA formation, and larger than the contribution from motor vehicles. This suggests that more research is needed in better constraining this potentially important source of urban VOC emissions.

  18. Sweet scents from good bacteria: Case studies on bacterial volatile compounds for plant growth and immunity.

    Science.gov (United States)

    Chung, Joon-hui; Song, Geun Cheol; Ryu, Choong-Min

    2016-04-01

    Beneficial bacteria produce diverse chemical compounds that affect the behavior of other organisms including plants. Bacterial volatile compounds (BVCs) contribute to triggering plant immunity and promoting plant growth. Previous studies investigated changes in plant physiology caused by in vitro application of the identified volatile compounds or the BVC-emitting bacteria. This review collates new information on BVC-mediated plant-bacteria airborne interactions, addresses unresolved questions about the biological relevance of BVCs, and summarizes data on recently identified BVCs that improve plant growth or protection. Recent explorations of bacterial metabolic engineering to alter BVC production using heterologous or endogenous genes are introduced. Molecular genetic approaches can expand the BVC repertoire of beneficial bacteria to target additional beneficial effects, or simply boost the production level of naturally occurring BVCs. The effects of direct BVC application in soil are reviewed and evaluated for potential large-scale field and agricultural applications. Our review of recent BVC data indicates that BVCs have great potential to serve as effective biostimulants and bioprotectants even under open-field conditions.

  19. Distribution of volatile compounds in the pulp, cloud, and serum of freshly squeezed orange juice.

    Science.gov (United States)

    Brat, Pierre; Rega, Barbara; Alter, Pascaline; Reynes, Max; Brillouet, Jean-Marc

    2003-05-21

    The quantitative distribution of volatile compounds in the pulp, cloud, and serum of a freshly squeezed orange juice (cv. Naveline) was measured. Juice monoterpene and sesquiterpene hydrocarbons were primarily recovered from the pulp (74.0 and 87.2%, respectively) and cloud (7.3 and 14.9%, respectively). Esters and monoterpene alcohols were mainly found in the serum (90.4 and 84.1%, respectively). Long chain aliphatic aldehydes tend to concentrate in the pulp. The relative proportions of individual volatile compounds were similar in the pulp and cloud. Pulp and cloud alcohol insoluble residues exhibited similar compositions; half of them are made of nonwall proteins, and the rest are made of cell wall materials. Pulp and cloud total and neutral lipids had similar fatty acids distributions, although the cloud was much richer in total lipids than the pulp. No relationship was found between the retention of aroma compounds in the pulp or cloud and their AIR and lipid content or composition.

  20. Cryogen free automated gas chromatography for the measurement of ambient volatile organic compounds.

    Science.gov (United States)

    Wang, J L; Chen, W L; Lin, Y H; Tsai, C H

    2000-10-27

    An automated gas chromatographic system was constructed for measuring ambient volatile organic compounds (VOCs). Preconcentration of the VOCs was performed by using two separated sorbent traps of different combinations with each designated for either low or high boiling VOCs. Both traps and their associated valve systems were integrated as a complete system sharing a common sample inlet. Precise temperature controls for desorption relied on the use of a process controller with proportional-integral-derivative algorithm to throttle the current supply. No additional cryo-focusing stage prior to the column was needed owing to the flash heating capability for desorption. Other than the cryogen free preconcentration and focusing, the separation of VOCs of large volatility difference was also performed without cryogen. The system employed an Al2O3/KCl porous-layer open tubular column for separating C3-C7 compounds; and a DB-1 column for C6-C12. This automated GC system has been deployed in a Taiwan Environmental Protection Agency urban air quality monitoring station of Taiwan for continuous measuring C3-C7 ozone precursors. Excellent correlation between the car exhaust type of compounds measured by our GC system and carbon monoxide measured by a non-dispersive infrared spectrometer was observed, suggesting the automated GC system was robust and reliable.

  1. Untargeted metabolomic analysis using liquid chromatography quadrupole time-of-flight mass spectrometry for non-volatile profiling of wines

    Energy Technology Data Exchange (ETDEWEB)

    Arbulu, M. [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Sampedro, M.C. [Central Service of Analysis, SGIker, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Gómez-Caballero, A.; Goicolea, M.A. [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Barrio, R.J., E-mail: r.barrio@ehu.es [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain)

    2015-02-09

    Highlights: • An untargeted metabolomic method for the non-volatile profile of the Graciano wine was developed. • 411 different metabolites in Graciano Vitis vinifera red wine were identified. • 15 compounds could serve to differentiate Graciano and Tempranillo wines. • An enological database (WinMet) with 2080 compounds was constructed. - Abstract: The current study presents a method for comprehensive untargeted metabolomic fingerprinting of the non-volatile profile of the Graciano Vitis vinifera wine variety, using liquid chromatography/electrospray ionization time of flight mass spectrometry (LC–ESI-QTOF). Pre-treatment of samples, chromatographic columns, mobile phases, elution gradients and ionization sources, were evaluated for the extraction of the maximum number of metabolites in red wine. Putative compounds were extracted from the raw data using the extraction algorithm, molecular feature extractor (MFE). For the metabolite identification the WinMet database was designed based on electronic databases and literature research and includes only the putative metabolites reported to be present in oenological matrices. The results from WinMet were compared with those in the METLIN database to evaluate how much the databases overlap for performing identifications. The reproducibility of the analysis was assessed using manual processing following replicate injections of Vitis vinifera cv. Graciano wine spiked with external standards. In the present work, 411 different metabolites in Graciano Vitis vinifera red wine were identified, including primary wine metabolites such as sugars (4%), amino acids (23%), biogenic amines (4%), fatty acids (2%), and organic acids (32%) and secondary metabolites such as phenols (27%) and esters (8%). Significant differences between varieties Tempranillo and Graciano were related to the presence of fifteen specific compounds.

  2. Volatile organic compounds from native potato-associated Pseudomonas as potential anti-oomycete agents.

    Directory of Open Access Journals (Sweden)

    Mout eDeVrieze

    2015-11-01

    Full Text Available The plant kingdom represents a prominent biodiversity island for microbes that associate with the below- or aboveground organs of vegetal species. Both the root and the leaf represent interfaces where dynamic biological interactions influence plant life. Beside well-studied communication strategies based on soluble compounds and protein effectors, bacteria were recently shown to interact both with host plants and other microbial species through the emissions of volatile organic compounds (VOCs. Focusing on the potato late blight-causing agent Phytophthora infestans, this work addresses the potential role of the bacterial volatilome in suppressing plant diseases. In a previous study, we isolated and identified a large collection of strains with anti-Phytophthora potential from both the phyllosphere and the rhizosphere of potato. Here we report the characterization and quantification of their emissions of biogenic volatiles, comparing 16 Pseudomonas strains differing in i origin of isolation (phyllosphere vs. rhizosphere, ii in vitro inhibition of P. infestans growth and sporulation behavior, and iii protective effects against late blight on potato leaf discs. We systematically tested the pharmacological inhibitory activity of core and strain-specific single compounds against P. infestans mycelial growth and sporangial behavior in order to identify key effective candidate molecules present in the complex natural VOCs blends. We envisage the plant bacterial microbiome as a reservoir for functional VOCs and establish the basis for finding the primary enzymatic toolset that enables the production of active components of the volatile bouquet in plant-associated bacteria. Comprehension of these functional interspecies interactions will open perspectives for the sustainable control of plant diseases in forthcoming agriculture.

  3. [Occurrence and distribution of volatile organic compounds in conventional and advanced drinking water treatment processes].

    Science.gov (United States)

    Chen, Xi-Chao; Luo, Qian; Chen, Hu; Wei, Zi; Wang, Zi-Jian; Xu, Ke-Wen

    2013-12-01

    A series of experiments were conducted to study the occurrence and distribution of volatile organic compounds (VOCs) in conventional and advanced drinking water treatment processes of 3 water treatment plants in Lianyungang City. Results showed that 30 compounds of 3 classes were detected from 67 kinds of VOCs in all the samples collected. The concentrations of carbonyl compounds, halogenated hydrocarbons and benzenes detected were in the ranges of 0.04-61.27, 0.02-35.61 and 0.07-2.33 microg x L(-1) respectively. Comparing the changes of different VOCs in three drinking water treatment plants, conventional chlorination process could effectively remove benzenes but meanwhile produced trihalomethanes (THMs). Additional advanced treatment ozonation-biological activated carbon process could decrease the formation of THMs during pre-chlorination but produced new risky contaminants like carbonyl compounds. The changes of VOCs in tap water were also investigated. It was found that carbonyl compounds produced by ozonation could be further transformed to THMs with residual chlorine. However, the health risks of all detected compounds in tap water were at a low level, except that the carcinogenic risk of crotonaldehydes (9.3 x 10(-5)-2.2 x 10(-4)) was slightly higher than the US EPA threshold (10(-6)-10(-4)).

  4. Extended Research on Detection of Deception Using Volatile Organic Compound (VOC) Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Center for Human Reliability Studies

    2006-06-01

    A system that captures and analyzes volatile organic compound (VOC) emissions from skin surfaces may offer a viable alternative method to the polygraph instrument currently in use for detecting deception in U.S. government settings. Like the involuntary autonomic central nervous system response data gathered during polygraph testing, VOC emissions from the skin may provide data that can be used to detect stress caused by deception. Detecting VOCs, then, may present a noninvasive, non-intrusive method for observing, recording, and quantifying evidence of stress or emotional change.

  5. Photo-activated luminescence sensor and method of detecting trichloroethylene and related volatile organochloride compounds

    Science.gov (United States)

    Dinh, Tuan V.

    1996-01-01

    A sensor for detecting trichloroethylene and related volatile organochloride compounds uses a photo-activator that produces a photo-product complex with the contaminant. Characteristics of the light emitted from the complex will indicate the presence of the contaminant. A probe containing the photo-activator has an excitation light interface and a contaminant interface. One particular embodiment uses a porous membrane as the contaminant interface, so that the contaminant can migrate therethrough to the photo-activator and thereby form the complex.

  6. Impact of air pressure on volatile organic compound emissions from a carpet

    Institute of Scientific and Technical Information of China (English)

    高鹏; 邓琴琴; LIN; Chao-hsin; 杨旭东

    2009-01-01

    The measurement of volatile organic compound (VOC) emissions from materials is normally conducted under standard environmental conditions, i.e., (23±1) ℃ temperature, (50±5)% relative humidity, and 0.1 MPa pressure. In order to define VOC emissions in non-standard environmental conditions, it is necessary to study the impact of key environmental parameters on emissions. This paper evaluates the impact of air pressure on VOC emissions from an aircraft carpet. The correlation between air pressure and VOC diffusion coefficient is derived, and the emission model is applied to studying the VOC emissions under pressure conditions of less than 0.1 MPa.

  7. Radon, volatile organic compounds and water chemistry in springs around Popocatepetl volcano, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N.; Pena, P.; Lopez, M.B.E.; Cisniega, G. [Inst. Nacional de Investigaciones Nucleares, Mexico D.F. (Mexico); Valdes, C.; Armienta, M.A.; Mena, M. [Inst. de Geofisica, UNAM, Ciudad Univ., Mexico D.F. (Mexico)

    2003-07-01

    Popocatepetl volcano is a high-risk active volcano in Central Mexico where the highest population density in the country is settled. Radon in the soil and groundwater together with water chemistry from samples of nearby springs is analysed as a function of the 2002-2003 volcanic activity. Soil radon indicated fluctuations related both to the meteorological and sporadic explosive events. Groundwater radon showed essentially differences in concentration due to the specific characteristics of the studied springs. Water chemistry showed also stability along the monitoring period indicating differences between springs. No anthropogenic pollution from volatile organic compounds was observed. (orig.)

  8. Micro- and Nanostructured Metal Oxide Chemical Sensors for Volatile Organic Compounds

    Science.gov (United States)

    Alim, M. A.; Penn, B. G.; Currie, J. R., Jr.; Batra, A. K.; Aggarwal, M. D.

    2008-01-01

    Aeronautic and space applications warrant the development of chemical sensors which operate in a variety of environments. This technical memorandum incorporates various kinds of chemical sensors and ways to improve their performance. The results of exploratory investigation of the binary composite polycrystalline thick-films such as SnO2-WO3, SnO2-In2O3, SnO2-ZnO for the detection of volatile organic compound (isopropanol) are reported. A short review of the present status of the new types of nanostructured sensors such as nanobelts, nanorods, nanotube, etc. based on metal oxides is presented.

  9. Multiscale Modelling Approach for a Fungal Biofilter Unit for the Hydrophobic Abatement of Volatile Organic Compounds

    DEFF Research Database (Denmark)

    Vergara-Fernández, A.; Rebolledo-Castro, J.; Morales Rodriguez, Ricardo

    2011-01-01

    Currently, biofiltration has become a viable and potential alternative for the treatment of airstreams with low concentrations of hydrophobic volatile organic compounds (VOCs), which can employ to this end, diverse microorganisms (such as, bacteria, fungal or microbial consortia, etc.) growing...... a biofilm. Usually, the design, analysis and scale-up of this kind of units have been mainly done via experimental approach, which can be costly in terms of time and resources. Therefore, the objective of this work is to introduce mathematical model for the prediction and simulation of a fungal biofilter...

  10. Development of a Surface Acoustic Wave Sensor for In-Situ Monitoring of Volatile Organic Compounds

    Directory of Open Access Journals (Sweden)

    Jerome L. Wright

    2003-07-01

    Full Text Available This paper describes the development of a surface-acoustic-wave (SAW sensor that is designed to be operated continuously and in situ to detect volatile organic compounds. A ruggedized stainless-steel package that encases the SAW device and integrated circuit board allows the sensor to be deployed in a variety of media including air, soil, and even water. Polymers were optimized and chosen based on their response to chlorinated aliphatic hydrocarbons (e.g., trichloroethylene, which are common groundwater contaminants. Initial testing indicates that a running-average data-logging algorithm can reduce the noise and increase the sensitivity of the in-situ sensor.

  11. Contact line pinning of a perfectly wetting and volatile liquid at a sharp edge

    Science.gov (United States)

    Tsoumpas, Yannis; Dehaeck, Sam; Rednikov, Alexey; Colinet, Pierre

    2011-11-01

    According to the Gibbs' criterion, a sharp edge can act as an energy barrier during the spreading of a liquid drop on a rigid substrate. In this study, however, we are trying to determine experimentally whether Gibbs' criterion is also valid for the case of a perfectly wetting and volatile liquid. To this purpose, we constructed a groove of triangular cross section on a Plexiglas substrate. During the experiments liquid was injected in the region surrounded by the groove, which had a square shape with rounded corners. The results indicated that a microgroove edge can indeed prevent the spreading of the liquid drop up to a certain extent, with the maximum apparent contact angle being in close agreement with the one given by Gibbs' criterion. Nevertheless, the apparent contact angle at breakup was found to be significantly lower in the corner of our region. To study this further we developed a static model, which takes into account surface tension and gravity but not the evaporation. Both the simulations and the experiments have confirmed a remarkable behaviour of the contact line at the corner. Finally, to grasp the effect of evaporation, experiments have also been conducted with drops of equally wetting but less volatile liquids. Supported by ESA & BELSPO, by the EU, and by FRS-FNRS.

  12. Exhaled volatile organic compounds for phenotyping chronic obstructive pulmonary disease: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Basanta Maria

    2012-08-01

    Full Text Available Abstract Background Non-invasive phenotyping of chronic respiratory diseases would be highly beneficial in the personalised medicine of the future. Volatile organic compounds can be measured in the exhaled breath and may be produced or altered by disease processes. We investigated whether distinct patterns of these compounds were present in chronic obstructive pulmonary disease (COPD and clinically relevant disease phenotypes. Methods Breath samples from 39 COPD subjects and 32 healthy controls were collected and analysed using gas chromatography time-of-flight mass spectrometry. Subjects with COPD also underwent sputum induction. Discriminatory compounds were identified by univariate logistic regression followed by multivariate analysis: 1. principal component analysis; 2. multivariate logistic regression; 3. receiver operating characteristic (ROC analysis. Results Comparing COPD versus healthy controls, principal component analysis clustered the 20 best-discriminating compounds into four components explaining 71% of the variance. Multivariate logistic regression constructed an optimised model using two components with an accuracy of 69%. The model had 85% sensitivity, 50% specificity and ROC area under the curve of 0.74. Analysis of COPD subgroups showed the method could classify COPD subjects with far greater accuracy. Models were constructed which classified subjects with ≥2% sputum eosinophilia with ROC area under the curve of 0.94 and those having frequent exacerbations 0.95. Potential biomarkers correlated to clinical variables were identified in each subgroup. Conclusion The exhaled breath volatile organic compound profile discriminated between COPD and healthy controls and identified clinically relevant COPD subgroups. If these findings are validated in prospective cohorts, they may have diagnostic and management value in this disease.

  13. Reaction of ozone with c5 and c6 biogenic volatile organic compounds

    Science.gov (United States)

    O Connor, M.; O Dwyer, M.; Wenger, J.

    2003-04-01

    REACTION OF OZONE WITH C5 AND C6 BIOGENIC VOLATILE ORGANIC COMPOUNDS M. O'Connor, M. O'Dwyer, J. Wenger CRAC-Centre for Research into Atmospheric Chemistry, Department of Chemistry, University College Cork, Ireland. jwenger@chemistry.ucc.ie Biogenic volatile organic compounds (BVOCs) account for around 90% of hydrocarbon emissionsinto the Earth's atmosphere. During the last ten years an increasing number of oxygenated BVOCs have also been detected in field measurement campaigns and plant emission studies. In particular a range of C5 and C6 oxygenates have been identifiedincluding compounds such as 1-penten-3-ol, E-2-hexenal and E-2-hexenyl acetate. The atmospheric impact of many of these compounds is largely unknown. The major atmospheric degradation processes for biogenic VOCs are gas-phase reaction with hydroxyl (OH) radicals, nitrate (NO3) radicals and ozone (O3). These reactions produce oxidized hydrocarbons, ozone and secondary organic aerosol and, as a result, exert a strong influence on the chemical compositionof the atmosphere. Although a number of studies have been made on the kinetics of the degradation of BVOCs, very few details are available concerning the reaction products and chemical mechanisms. In this work we have studied the reaction of O3 with a series of C5 unsaturated alcohols and C6 unsaturated aldehydes. Rate coefficients for these reactions have been studied using the relative rate method and gas-phase oxidation products have been identified using FTIR spectroscopy and PFBHA derivatisation coupled with GC-MS analysis. In addition secondary organic aerosol (SOA) formation has been studied as a function of humidity. The data obtained in this work will be used to further our knowledge of the atmospheric degradation of these naturally occurring compounds.

  14. Toxic volatile organic compounds in environmental tobacco smoke: Emission factors for modeling exposures of California populations

    Energy Technology Data Exchange (ETDEWEB)

    Daisey, J.M.; Mahanama, K.R.R.; Hodgson, A.T. [Lawrence Berkeley Lab., CA (United States)

    1994-10-01

    The primary objective of this study was to measure emission factors for selected toxic air contaminants in environmental tobacco smoke (ETS) using a room-sized environmental chamber. The emissions of 23 volatile organic compounds (VOCs), including, 1,3-butadiene, three aldehydes and two vapor-phase N-nitrosamines were determined for six commercial brands of cigarettes and reference cigarette 1R4F. The commercial brands were selected to represent 62.5% of the cigarettes smoked in California. For each brand, three cigarettes were machine smoked in the chamber. The experiments were conducted over four hours to investigate the effects of aging. Emission factors of the target compounds were also determined for sidestream smoke (SS). For almost all target compounds, the ETS emission factors were significantly higher than the corresponding SS values probably due to less favorable combustion conditions and wall losses in the SS apparatus. Where valid comparisons could be made, the ETS emission factors were generally in good agreement with the literature. Therefore, the ETS emission factors, rather than the SS values, are recommended for use in models to estimate population exposures from this source. The variabilities in the emission factors ({mu}g/cigarette) of the selected toxic air contaminants among brands, expressed as coefficients of variation, were 16 to 29%. Therefore, emissions among brands were Generally similar. Differences among brands were related to the smoked lengths of the cigarettes and the masses of consumed tobacco. Mentholation and whether a cigarette was classified as light or regular did not significantly affect emissions. Aging was determined not to be a significant factor for the target compounds. There were, however, deposition losses of the less volatile compounds to chamber surfaces.

  15. Final report on CCQM-K47: Volatile organic compounds in methanol

    Science.gov (United States)

    Pérez Urquiza, Melina; Maldonado Torres, Mauricio; Mitani, Yoshito; Schantz, Michele M.; Duewer, David L.; May, Wille E.; Parris, Reenie M.; Wise, Stephen A.; Kaminski, Katja; Philipp, Rosemarie; Win, Tin; Rosso, Adriana; Kim, Dal Ho; Ishikawa, Keiichiro; Krylov, A. I.; Kustikov, Y. A.; Baldan, Annarita

    2013-01-01

    At the October 2005 CCQM Organic Analysis Working Group Meeting (IRMM, Belgium), the decision was made to proceed with a Key Comparison study (CCQM-K47) addressing the calibration function for the determination of volatile organic compounds (VOCs) used for water quality monitoring. This was coordinated by CENAM and NIST. Benzene, o-xylene, m-xylene and p-xylene were chosen as representative VOCs. The solvent of choice was methanol. Key Comparison CCQM-K47 demonstrated the capabilities of participating NMIs to identify and measure the four target VOCs in a calibration solution using GC-based methods. The measurement challenges in CCQM-K47, such as avoiding volatility loss, achieving adequate chromatographic resolution and isolating potential interferences, are typical of those required for value-assigning volatile reference materials. Participants achieving comparable measurements for all four VOCs in this Key Comparison should be capable of providing reference materials and measurements for VOCs in solutions when present at concentration levels greater than 10 µg/g. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  16. Growth and volatile compound production by Brettanomyces/Dekkera bruxellensis in red wine.

    Science.gov (United States)

    Romano, A; Perello, M C; de Revel, G; Lonvaud-Funel, A

    2008-06-01

    Brettanomyces/Dekkera bruxellensis is a particularly troublesome wine spoilage yeast. This work was aimed at characterizing its behaviour in terms of growth and volatile compound production in red wine. Sterile red wines were inoculated with 5 x 10(3) viable cells ml(-1) of three B. bruxellensis strains and growth and volatile phenol production were followed for 1 month by means of plate counts and gas chromatography-mass spectrometry (GC-MS) respectively. Maximum population levels generally attained 10(6)-10(7) colony forming units (CFU) ml(-1) and volatile phenol concentrations ranged from 500 to 4000 microg l(-1). Brettanomyces bruxellensis multiplication was also accompanied by the production of organic acids (from C(2) to C(10)), short chain acid ethyl-esters and the 'mousy off-flavour' component 2-acetyl-tetrahydropyridine. Different kinds of 'Brett character' characterized by distinct metabolic and sensory profiles can arise in wine depending on the contaminating strain, wine pH and sugar content and the winemaking stage at which contamination occurs. We identified new chemical markers that indicate wine defects caused by B. bruxellensis. Further insight was provided into the role of some environmental conditions in promoting wine spoilage.

  17. An improved, automated whole air sampler and gas chromatography mass spectrometry analysis system for volatile organic compounds in the atmosphere

    Science.gov (United States)

    Lerner, Brian M.; Gilman, Jessica B.; Aikin, Kenneth C.; Atlas, Elliot L.; Goldan, Paul D.; Graus, Martin; Hendershot, Roger; Isaacman-VanWertz, Gabriel A.; Koss, Abigail; Kuster, William C.; Lueb, Richard A.; McLaughlin, Richard J.; Peischl, Jeff; Sueper, Donna; Ryerson, Thomas B.; Tokarek, Travis W.; Warneke, Carsten; Yuan, Bin; de Gouw, Joost A.

    2017-01-01

    Volatile organic compounds were quantified during two aircraft-based field campaigns using highly automated, whole air samplers with expedited post-flight analysis via a new custom-built, field-deployable gas chromatography-mass spectrometry instrument. During flight, air samples were pressurized with a stainless steel bellows compressor into electropolished stainless steel canisters. The air samples were analyzed using a novel gas chromatograph system designed specifically for field use which eliminates the need for liquid nitrogen. Instead, a Stirling cooler is used for cryogenic sample pre-concentration at temperatures as low as -165 °C. The analysis system was fully automated on a 20 min cycle to allow for unattended processing of an entire flight of 72 sample canisters within 30 h, thereby reducing typical sample residence times in the canisters to less than 3 days. The new analytical system is capable of quantifying a wide suite of C2 to C10 organic compounds at part-per-trillion sensitivity. This paper describes the sampling and analysis systems, along with the data analysis procedures which include a new peak-fitting software package for rapid chromatographic data reduction. Instrument sensitivities, uncertainties and system artifacts are presented for 35 trace gas species in canister samples. Comparisons of reported mixing ratios from each field campaign with measurements from other instruments are also presented.

  18. Volatile organic compound emissions from arctic vegetation highly responsive to experimental warming

    Science.gov (United States)

    Rinnan, Riikka; Kramshøj, Magnus; Lindwall, Frida; Schollert, Michelle; Svendsen, Sarah H.; Valolahti, Hanna

    2017-04-01

    Arctic areas are experiencing amplified climate warming that proceeds twice as fast as the global temperature increase. The increasing temperature is already causing evident alterations, e.g. changes in the vegetation cover as well as thawing of permafrost. Climate warming and the concomitant biotic and abiotic changes are likely to have strong direct and indirect effects on emission of volatile organic compounds (VOCs) from arctic vegetation. We used long-term field manipulation experiments in the Subarctic, Low Arctic and High Arctic to assess effects of climate change on VOC emissions from vegetation communities. In these experiments, we applied passive warming with open-top chambers alone and in combination with other experimental treatments in well-replicated experimental designs. Volatile emissions were sampled in situ by drawing air from plant enclosures and custom-built chambers into adsorbent cartridges, which were analyzed by thermal desorption and gas chromatography-mass spectrometry in laboratory. Emission increases by a factor of 2-5 were observed under experimental warming by only a few degrees, and the strong response seems universal for dry, mesic and wet ecosystems. In some cases, these vegetation community level responses were partly due to warming-induced increases in the VOC-emitting plant biomass, changes in species composition and the following increase in the amount of leaf litter (Valolahti et al. 2015). In other cases, the responses appeared before any vegetation changes took place (Lindwall et al. 2016) or even despite a decrease in plant biomass (Kramshøj et al. 2016). VOC emissions from arctic ecosystems seem more responsive to experimental warming than other ecosystem processes. We can thus expect large increases in future VOC emissions from this area due to the direct effects of temperature increase, and due to increasing plant biomass and a longer growing season. References Kramshøj M., Vedel-Petersen I., Schollert M., Rinnan

  19. An investigation on the chemotactic responses of different entomopathogenic nematode strains to mechanically damaged maize root volatile compounds.

    Science.gov (United States)

    Laznik, Z; Trdan, S

    2013-07-01

    Entomopathogenic nematodes (EPNs) respond to a variety of stimuli when foraging. In a laboratory investigation, we tested the chemotactic responses of 8 EPN strains (Steinernema and Heterorhabditis) to three mechanically damaged maize root compounds (linalool, α-caryophyllene and β-caryophyllene). We hypothesized that the EPN directional response to the tested volatile compounds would vary among the species and volatile compound and may be related to foraging strategies. The nematodes with an intermediate foraging strategy (Steinernema feltiae) proved to be less active in their movement toward volatile compounds in a comparison with the ambushers (Steinernema carpocapsae) and cruisers (Steinernema kraussei and Heterorhabditis bacteriophora); β-caryophyllene was found to be the most attractive substance in our experiment. The results of our investigation showed that the cruisers were more attracted to β-caryophyllene than the ambushers and intermediates. The foraging strategy did not affect the movement of the IJs toward the other tested volatile compounds or the control. Our results suggest that the response to different volatile cues is more a strain-specific characteristic than a different host-searching strategy. Only S. carpocapsae strain B49 displayed an attraction to linalool, whereas S. kraussei showed a retarded reaction to β-caryophyllene and α-caryophyllene in our experiment. The EPN strains showed only a weak attraction to α-caryophyllene, suggesting that this volatile compound could not have an important role in the orientation of IJs to the damaged roots of maize plants. These results expand our knowledge of volatile compounds as the cues that may be used by EPNs for finding hosts or other aspects of navigation in the soil. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Air monitoring of volatile organic compounds at relevant receptors during hydraulic fracturing operations in Washington County, Pennsylvania.

    Science.gov (United States)

    Maskrey, Joshua R; Insley, Allison L; Hynds, Erin S; Panko, Julie M

    2016-07-01

    A 3-month air monitoring study was conducted in Washington County, Pennsylvania, at the request of local community members regarding the potential risks resulting from air emissions of pollutants related to hydraulic fracturing operations. Continuous air monitoring for total volatile organic compounds was performed at two sampling sites, including a school and a residence, located within 900 m of a hydraulic fracturing well pad that had been drilled prior to the study. Intermittent 24-hour air samples for 62 individual volatile organic compounds were also collected. The ambient air at both sites was monitored during four distinct periods of unconventional natural gas extraction activity: an inactive period prior to fracturing operations, during fracturing operations, during flaring operations, and during another inactive period after operations. The results of the continuous monitoring during fracturing and flaring sampling periods for total volatile organic compounds were similar to the results obtained during inactive periods. Total volatile organic compound 24-hour average concentrations ranged between 0.16 and 80 ppb during all sampling periods. Several individual volatile compounds were detected in the 24-hour samples, but they were consistent with background atmospheric levels measured previously at nearby sampling sites and in other areas in Washington County. Furthermore, a basic yet conservative screening level evaluation demonstrated that the detected volatile organic compounds were well below health-protective levels. The primary finding of this study was that the operation of a hydraulic fracturing well pad in Washington County did not substantially affect local air concentrations of total and individual volatile organic compounds.

  1. Vine-shoot waste aqueous extracts for re-use in agriculture obtained by different extraction techniques: phenolic, volatile, and mineral compounds.

    Science.gov (United States)

    Sánchez-Gómez, Rosario; Zalacain, Amaya; Alonso, Gonzalo L; Salinas, M Rosario

    2014-11-12

    Vine-shoots are an important waste in all viticulture areas that should be re-used with innovative applications. The aim of this work was to produce Airén waste vine-shoot aqueous extracts by four solid-liquid extraction techniques such as conventional solid-liquid extraction (CSLE), solid-liquid dynamic extraction (SLDE-Naviglio), microwave extraction (ME), and pressurized solvent extraction (PSE). Their chemical composition was studied in terms of phenolic, volatile, and mineral compounds. The highest concentrated extracts corresponded to CSLE and SLDE-Naviglio, independent of the conditions tested. The CSLE extracts had the highest flavanols, phenolic acids, and stilbenes contents. The volatile composition, quantified for first time in this work, shows that furanic compounds were the most abundant. All extracts showed an interesting mineral content, which may be assimilated by plants. These results show the agricultural potential of Airén vine-shoot waste aqueous extracts to be used as grape biostimulants and/or foliar fertilizer.

  2. Volatile compounds analysis and antioxidant, antimicrobial and cytotoxic activities of Mindium laevigatum

    Directory of Open Access Journals (Sweden)

    Abdolrasoul Haghir Ebrahimabadi

    2016-12-01

    Full Text Available Objective(s: Mindium laevigatum is an endemic plant of Iran and Turkey and is widely used as blood purifier, antiasthma and antidyspnea in traditional medicine. Chemical composition of volatile materials of the plant and its antioxidant, antimicrobial and cytotoxic activities were reported in this study. Materials and Methods: Simultaneous distillation-extraction (SDE and GC-Mass-FID analysis were used for the plant volatile materials chemical composition identification and quantification. Several antioxidant tests including DPPH radical scavenging, hydrogen peroxide scavenging, reducing power determination, β-carotene-linoleic acid and total phenolic content tests were used for antioxidant activity evaluation. Antimicrobial and anticancer activities were also estimated using microbial strains, cancer cell lines and brine shrimp larva. Results: GC-Mass-FID analysis of volatile samples showed a total of 74 compounds of which palmitic acid (7.4-33.7%, linoleic acid (6.6-18.6%, heneicosane (1.3-9.6% and myristic acid (1.4-6.0% were detected as main volatile components. Moderate to good results were recorded for the plant in              β-carotene-linoleic acid test. Total phenolic content of the extracts as gallic acid equivalents were estimated in the range of 15.7 to 79.6 μg/mg. Some microbial strains showed moderate sensitivities to plant extracts. Brine shrimp lethality test and cytotoxic cancer cell line assays showed mild cytotoxic activities for the plant. Conclusion: Moderate to good antioxidant activities in β-carotene-linoleic acid test and presence of considerable amounts of unsaturated hydrocarbons may explain the plant traditional use in asthma and dyspnea. These findings also candidate it as a good choice for investigating its possible modern medical applications.

  3. Volatile compounds analysis and antioxidant, antimicrobial and cytotoxic activities of Mindium laevigatum

    Science.gov (United States)

    Ebrahimabadi, Abdolrasoul Haghir; Movahedpour, Mohammad Mahdi; Batooli, Hossain; Ebrahimabadi, Ebrahim Haghir; Mazoochi, Asma; Qamsari, Maryam Mobarak

    2016-01-01

    Objective(s): Mindium laevigatum is an endemic plant of Iran and Turkey and is widely used as blood purifier, antiasthma and antidyspnea in traditional medicine. Chemical composition of volatile materials of the plant and its antioxidant, antimicrobial and cytotoxic activities were reported in this study. Materials and Methods: Simultaneous distillation-extraction (SDE) and GC-Mass-FID analysis were used for the plant volatile materials chemical composition identification and quantification. Several antioxidant tests including DPPH radical scavenging, hydrogen peroxide scavenging, reducing power determination, β-carotene-linoleic acid and total phenolic content tests were used for antioxidant activity evaluation. Antimicrobial and anticancer activities were also estimated using microbial strains, cancer cell lines and brine shrimp larva. Result: s: GC-Mass-FID analysis of volatile samples showed a total of 74 compounds of which palmitic acid (7.4-33.7%), linoleic acid (6.6-18.6%), heneicosane (1.3-9.6%) and myristic acid (1.4-6.0%) were detected as main volatile components. Moderate to good results were recorded for the plant in β-carotene-linoleic acid test. Total phenolic content of the extracts as gallic acid equivalents were estimated in the range of 15.7 to 79.6 μg/mg. Some microbial strains showed moderate sensitivities to plant extracts. Brine shrimp lethality test and cytotoxic cancer cell line assays showed mild cytotoxic activities for the plant. Conclusion: Moderate to good antioxidant activities in β-carotene-linoleic acid test and presence of considerable amounts of unsaturated hydrocarbons may explain the plant traditional use in asthma and dyspnea. These findings also candidate it as a good choice for investigating its possible modern medical applications. PMID:28096967

  4. Compound liquid crystal microlens array with convergent and divergent functions.

    Science.gov (United States)

    Kang, Shengwu; Zhang, Xinyu

    2016-04-20

    Based on the common liquid crystal microlens, a new compound structure for a liquid crystal (LC) microlens array is proposed. The structure consists of two sub LC microlens arrays with properties of light divergence and convergence. The structure has two LC layers: one to form the positive sub lens, one for the negative. The patterned electrode and plane electrode are used in both sub microlens arrays. When two sub microlens arrays are electrically controlled separately, they can diverge or converge the incident light, respectively. As two sub microlens arrays are both applied on the voltage, the focal length of the compound LC microlens becomes larger than that of the LC microlens with a single LC layer. Another feature of a compound LC microlens array is that it can make the target contour become visible under intense light. The mechanisms are described in detail, and the experimental data are given.

  5. Reactions of Lignin Model Compounds in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, John E.; Binder, Joseph B.; Gray, Michel J.; White, James F.; Zhang, Z. Conrad

    2009-09-15

    Lignin, a readily available form of biomass, awaits novel chemistry for converting it to valuable aromatic chemicals. Recent work has demonstrated that ionic liquids are excellent solvents for processing woody biomass and lignin. Seeking to exploit ionic liquids as media for depolymerization of lignin, we investigated reactions of lignin model compounds in these solvents. Using Brønsted acid catalysts in 1-ethyl-3-methylimidazolium triflate at moderate temperatures, we obtained up to 11.6% yield of the dealkylation product guaiacol from the model compound eugenol and cleaved phenethyl phenyl ether, a model for lignin ethers. Despite these successes, acid catalysis failed in dealkylation of the unsaturated model compound 4-ethylguaiacol and did not produce monomeric products from organosolv lignin, demonstrating that further work is required to understand the complex chemistry of lignin depolymerization.

  6. Ternary liquid-liquid equilibria for the phenolic compounds extraction from artificial textile industrial waste

    Science.gov (United States)

    Fardhyanti, Dewi Selvia; Prasetiawan, Haniif; Hermawan, Sari, Lelita Sakina

    2017-03-01

    Liquid waste in textile industry contains large amounts of dyes and chemicals which are capable of harming the environment and human health. It is due to liquid waste characteristics which have high BOD, COD, temperature, dissolved and suspended solid. One of chemical compound which might be harmful for environment when disposed in high concentration is phenol. Currently, Phenol compound in textile industrial waste has reached 10 ppm meanwhile maximum allowable phenol concentration is not more than 0.2 ppm. Otherwise, Phenol also has economic value as feedstock of plastic, pharmaceutical and cosmetic industry. Furthermore, suitable method to separate phenol from waste water is needed. In this research, liquid - liquid extraction method was used with extraction time for 70 minutes. Waste water sample was then separated into two layers which are extract and raffinate. Thereafter, extract and raffinate were then tested by using UV-Vis Spectrophotometer to obtained liquid - liquid equilibrium data. Aim of this research is to study the effect of temperature, stirring speed and type of solvent to obtain distribution coefficient (Kd), phenol yield and correlation of Three-Suffix Margules model for the liquid - liquid extraction data equilibrium. The highest extraction yield at 80.43 % was found by using 70% methanol as solvent at extraction temperature 50 °C with stirring speed 300 rpm, coefficient distribution was found 216.334. From this research it can be concluded that Three-Suffix Margules Model is suitable to predict liquid - liquid equilibrium data for phenol system.

  7. Comparison of two extraction techniques, solid-phase microextraction versus continuous liquid-liquid extraction/solvent-assisted flavor evaporation, for the analysis of flavor compounds in gueuze lambic beer.

    Science.gov (United States)

    Thompson-Witrick, Katherine A; Rouseff, Russell L; Cadawallader, Keith R; Duncan, Susan E; Eigel, William N; Tanko, James M; O'Keefe, Sean F

    2015-03-01

    Lambic is a beer style that undergoes spontaneous fermentation and is traditionally produced in the Payottenland region of Belgium, a valley on the Senne River west of Brussels. This region appears to have the perfect combination of airborne microorganisms required for lambic's spontaneous fermentation. Gueuze lambic is a substyle of lambic that is made by mixing young (approximately 1 year) and old (approximately 2 to 3 years) lambics with subsequent bottle conditioning. We compared 2 extraction techniques, solid-phase microextraction (SPME) and continuous liquid-liquid extraction/solvent-assisted flavor evaporation (CCLE/SAFE), for the isolation of volatile compounds in commercially produced gueuze lambic beer. Fifty-four volatile compounds were identified and could be divided into acids (14), alcohols (12), aldehydes (3), esters (20), phenols (3), and miscellaneous (2). SPME extracted a total of 40 volatile compounds, whereas CLLE/SAFE extracted 36 volatile compounds. CLLE/SAFE extracted a greater number of acids than SPME, whereas SPME was able to isolate a greater number of esters. Neither extraction technique proved to be clearly superior and both extraction methods can be utilized for the isolation of volatile compounds found in gueuze lambic beer.

  8. Substitution effect in reversible gel-liquid phase transformation polyoxometalate ionic liquid compounds.

    Science.gov (United States)

    Wu, Xuefei; Cai, Huaxue; Wu, Qingyin; Yan, Wenfu

    2016-07-28

    The substitution effect in a series of POM-type reversible gel-liquid phase transformation ionic liquid compounds, [MIMPS]8P2W16V2O62, [MIMPS]6H2P2W16V2O62 and [MIMPS]4H4P2W16V2O62, has been investigated. Interestingly, there is an obvious substitution effect on the physicochemical properties of these compounds. When protons are substituted in place of ammonium, both the conductivity and the thermo-stability of the compounds can be increased a lot, and more protons can enhance this tendency.

  9. Minor Volatile Compounds Profiles of ‘Aligoté’ Wines Fermented with Different Yeast Strains

    Directory of Open Access Journals (Sweden)

    Florin VARARU

    2015-03-01

    Full Text Available The aroma of wine can be classified accordingly to its origin, in varietal aroma, pre-fermentative aroma, fermentative aroma and post-fermentative aroma. Although a number of flavor components are found in the original grape, the dominant and major compounds contributing to white wines are formed during alcoholic fermentation, in concordance with the yeast strain used. In order to highlight the influence of the yeast strain to the aroma composition of wines, wine samples from ‘Aligoté’ grape variety made with 8 different yeast strains were subjected to stir bar sorptive extraction-gas chromatography-mass spectrometry (SBSE-GC-MS analyses. Also, a sensorial analysis of the studied wines was performed by a tasting panel consisting of 15 tasters. 38 minor volatile compounds were quantified by SBSE-GC-MS technique. Different concentration of the same compound and different aroma compounds were identified and quantified in wines obtained with different yeast strains. A wine finger printing was obtained by multivariate data analyses of aroma compounds grouped by chemical families. The analytical and sensorial analysis of the wine samples confirms that there are differences in aroma composition of the wines made with different yeast strains.

  10. Nanogram-scale preparation and NMR analysis for mass-limited small volatile compounds.

    Directory of Open Access Journals (Sweden)

    Satoshi Nojima

    Full Text Available Semiochemicals are often produced in infinitesimally small quantities, so their isolation requires large amounts of starting material, not only requiring significant effort in sample preparation, but also resulting in a complex mixture of compounds from which the bioactive compound needs to be purified and identified. Often, compounds cannot be unambiguously identified by their mass spectra alone, and NMR analysis is required for absolute chemical identification, further exacerbating the situation because NMR is relatively insensitive and requires large amounts of pure analyte, generally more than several micrograms. We developed an integrated approach for purification and NMR analysis of <1 µg of material. Collections from high performance preparative gas-chromatography are directly eluted with minimal NMR solvent into capillary NMR tubes. With this technique, (1H-NMR spectra were obtained on 50 ng of geranyl acetate, which served as a model compound, and reasonable H-H COSY NMR spectra were obtained from 250 ng of geranyl acetate. This simple off-line integration of preparative GC and NMR will facilitate the purification and chemical identification of novel volatile compounds, such as insect pheromones and other semiochemicals, which occur in minute (sub-nanogram, and often limited, quantities.

  11. The determination of botanical origin of honeys based on enantiomer distribution of chiral volatile organic compounds.

    Science.gov (United States)

    Špánik, Ivan; Pažitná, Alexandra; Šiška, Peter; Szolcsányi, Peter

    2014-09-01

    The enantiomer ratios of chiral volatile organic compounds in rapeseed, chestnut, orange, acacia, sunflower and linden honeys were determined by multi-dimensional gas chromatography using solid phase microextraction (SPME) as a sample pre-treatment procedure. Linalool oxides, linalool and hotrienol were present at the highest concentration levels, while significantly lower amounts of α-terpineol, 4-terpineol and all isomers of lilac aldehydes were found in all studied samples. On the other hand, enantiomer distribution of some chiral organic compounds in honey depends on their botanical origin. The significant differences in enantiomer ratio of linalool were observed for rapeseed honey that allows us to distinguish this type of honey from the other ones. The enantiomer ratios of lilac aldehydes were useful for distinguishing of orange and acacia honey from other studied monofloral honeys. Similarly, different enantiomer ratio of 4-terpineol was found for sunflower honeys.

  12. Quantification of volatile organic compounds in smoke from prescribed burning and comparison with occupational exposure limits

    Science.gov (United States)

    Romagnoli, E.; Barboni, T.; Santoni, P.-A.; Chiaramonti, N.

    2014-05-01

    Prescribed burning represents a serious threat to personnel fighting fires due to smoke inhalation. The aim of this study was to investigate exposure by foresters to smoke from prescribed burning, focusing on exposure to volatile organic compounds (VOCs). The methodology for smoke sampling was first evaluated. Potentially dangerous compounds were identified among the VOCs emitted by smoke fires at four prescribed burning plots located around Corsica. The measured mass concentrations for several toxic VOCs were generally higher than those measured in previous studies due to the experimental framework (short sampling distance between the foresters and the flame, low combustion, wet vegetation). In particular, benzene, phenol and furfural exceeded the legal short-term exposure limits published in Europe and/or the United States. Other VOCs such as toluene, ethybenzene or styrene remained below the exposure limits. In conclusion, clear and necessary recommendations were made for protection of personnel involved in fighting fires.

  13. Volatile organic compounds and trace metal level in some beers collected from Romanian market

    Science.gov (United States)

    Voica, Cezara; Kovacs, Melinda; Vadan, Marius

    2013-11-01

    Beer is one of the most popular beverages at worldwide level. Through this study fifteen different types of beer collected from Romanian market were analysed in order to evaluate their mineral, trace element as well the their organic content. Importance of such characterization of beer samples is supported by the fact that their chemical composition can affect both taste and stability of beer, as well the consumer health. Minerals and trace elements analysis were performed on ICP-MS while organic compounds analysis was done through GC-MS. Through ICP-MS analysis, elements as Ca, Na, K and Mg were evidenced at mgṡkg-1 order while elements as Cr, Ba, Co, Ni were detected at lower level. After GC-MS analysis the major volatile compounds that were detected belong to alcohols namely ethanol, propanol, isobutanol, isoamyl alcohol and linalool. Selected fatty acids and esters were evidenced also in the studied beer samples.

  14. Using Back Trajectories to Analyze Volatile Organic Compound Source Distributions in California's San Joaquin Valley

    Science.gov (United States)

    Ford, T. B.; Gentner, D. R.; Brioude, J.; Angevine, W. M.; Karlik, J. F.; Goldstein, A. H.

    2012-12-01

    Volatile organic compounds (VOCs) are emitted from a variety of biogenic and anthropogenic sources that vary in their degree of characterization. Using WRF/FLEXPART transport modeling and ~2 months of ambient in-situ VOC concentration data from two sites in the San Joaquin Valley (an urban site in Bakersfield, CA and a rural site near Visalia, CA), we assess the spatial distribution of VOC sources. Concentration Weighted Trajectory (CWT) analysis was used to statistically examine the distribution of VOC sources in California's San Joaquin Valley over six and twelve-hour back trajectory footprints. We present the overall flow patterns that determine the transport during the day and night at both San Joaquin Valley sites. The results of the CWT analysis using the ground site VOC data show clear differences in distributions between compounds and provide valuable insights into the potential sources of various classes of biogenic and anthropogenic VOCs.

  15. Fungal volatile compounds induce production of the secondary metabolite Sodorifen in Serratia plymuthica PRI-2C.

    Science.gov (United States)

    Schmidt, Ruth; Jager, Victor de; Zühlke, Daniela; Wolff, Christian; Bernhardt, Jörg; Cankar, Katarina; Beekwilder, Jules; Ijcken, Wilfred van; Sleutels, Frank; Boer, Wietse de; Riedel, Katharina; Garbeva, Paolina

    2017-04-13

    The ability of bacteria and fungi to communicate with each other is a remarkable aspect of the microbial world. It is recognized that volatile organic compounds (VOCs) act as communication signals, however the molecular responses by bacteria to fungal VOCs remain unknown. Here we perform transcriptomics and proteomics analyses of Serratia plymuthica PRI-2C exposed to VOCs emitted by the fungal pathogen Fusarium culmorum. We find that the bacterium responds to fungal VOCs with changes in gene and protein expression related to motility, signal transduction, energy metabolism, cell envelope biogenesis, and secondary metabolite production. Metabolomic analysis of the bacterium exposed to the fungal VOCs, gene cluster comparison, and heterologous co-expression of a terpene synthase and a methyltransferase revealed the production of the unusual terpene sodorifen in response to fungal VOCs. These results strongly suggest that VOCs are not only a metabolic waste but important compounds in the long-distance communication between fungi and bacteria.

  16. Determination of Volatile Organic Compounds in the Atmosphere Using Two Complementary Analysis Techniques.

    Science.gov (United States)

    Alonso, L; Durana, N; Navazo, M; García, J A; Ilardia, J L

    1999-08-01

    During a preliminary field campaign of volatile organic compound (VOC) measurements carried out in an urban area, two complementary analysis techniques were applied to establish the technical and scientific bases for a strategy to monitor and control VOCs and photochemical oxidants in the Autonomous Community of the Basque Country. Integrated sampling was conducted using Tenax sorbent tubes and laboratory analysis by gas chromatography, and grab sampling and in situ analysis also were conducted using a portable gas chromatograph. With the first technique, monocyclic aromatic hydrocarbons appeared as the compounds with the higher mean concentrations. The second technique allowed the systematic analysis of eight chlorinated and aromatic hydrocarbons. Results of comparing both techniques, as well as the additional information obtained with the second technique, are included.

  17. Ion chemistry for the detection of isoprene and other volatile organic compounds in ambient air

    Science.gov (United States)

    Leibrock, Edeltraud; Huey, L. Gregory

    2000-06-01

    A chemical ionization mass spectrometer (CIMS) and a flowing afterglow apparatus were used to study reactions of benzene cations (C6H6+ and (C6H6)2+) with a series of volatile organic compounds (VOCs). Both cations react at the collision rate with compounds of lower ionization potential than benzene, such as isoprene (C5H8), other conjugated dienes, and aromatics. These ions are generally unreactive with substances of higher ionization potential such as alkanes, simple alcohols, simple carbonyls, etc. The results demonstrate that C6H6+ and (C6H6)2+ are excellent reagent ions for the sensitive detection of isoprene in air with a CIMS. However, 2-methyl-3-buten-2-ol (MBO) and C5H8 conjugated dienes were identified as potential interferences to this technique. This indicates that the selectivity of the CIMS isoprene measurement must be tested by intercomparison with well-established methods, e.g. gas chromatography techniques.

  18. Differential volatile organic compounds in royal jelly associated with different nectar plants

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ya-zhou; LI Zhi-guo; TIAN Wen-li; FANG Xiao-ming; SU Song-kun; PENG Wen-jun

    2016-01-01

    The aim of this work was to distinguish volatile organic compound (VOC) proifles of royal jely (RJ) from different nectar plants. Headspace solid-phase microextraction (HS-SPME) was used to extract VOCs from raw RJ harvested from 10 nectar plants in lfowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry (GC-MS). Results showed that VOC proifles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exempliifed by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.

  19. Potential of volatile compounds produced by fungi to influence sensory quality of coffee beverage

    DEFF Research Database (Denmark)

    Iamanaka, B. T.; Teixeira, A. A.; Teixeira, A. R. R.

    2014-01-01

    Fungi are known producers of a large number of volatile compounds (VCs). Several VCs such as 2,4,6 trichloroanisole (TCA), geosmin and terpenes have been found in coffee beverages, and these compounds can be responsible for off-flavor development. However, few studies have related the fungal...... contamination of coffee with the sensory characteristics of the beverage. The aim of this research was to investigate the production of VCs by fungi isolated from coffee and their potential as modifiers of the sensory coffee beverage quality. Three species were isolated from coffee from the southwest of São...... Paulo state and selected for the study: Penicillium brevicompactum, Aspergillus luchuensis (belonging to section Nigri) and Penicillium sp. nov. (related to Penicillium crustosum). VCs produced by the fungal inoculated in raw coffee beans were extracted and tentatively identified by SPME...

  20. Critical role of a pre-purge setup in the thermal desorption analysis of volatile organic compounds by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2015-07-01

    In general, volatile organic compounds in ambient air are quantified by following a well-defined standard calibration procedure using a gas-/liquid-phase standard. If the liquid standard is analyzed by a thermal desorption, the solvent effect is unavoidable through the alteration of breakthrough properties or retention times. To learn more about the variables of the thermal desorption-based analysis, the effect of pre-purge conditions was evaluated for 18 volatile organic compounds with different types of sorbent tube materials by fixing standard volume (1 μL) and flow rate (100 mL/min). The gas phase calibration was also carried out as reference for the non-solvent effect. A single tube filled with Tenax TA exhibited the least solvent effect with the short pre-purge (1 min), while being subject to the breakthrough at or above 10 min pre-purge. For a three-bed sorbent tube with Carboxen 1000, at least 10 min of pre-purge was needed for the compounds with a retention time close to methanol (e.g., propanal). Another three-bed tube with Carbopack X reduced the solvent effect efficiently for a short pre-purge (2 min) without the breakthrough. As such, the solvent effect can be adjusted by the proper control of the sorbent tube application.