These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Investigation on the evolution of N-containing organic compounds during pyrolysis of sewage sludge.  

PubMed

Pyrolysis is an emerging technology for the disposal of huge amounts of sewage sludge. However, the thermochemical decomposition mechanism of organic compounds in sludge is still unclear. We adopt a novel online TG-FTIR-MS technology to investigate the pyrolysis of sludge. The sludge samples were pyrolyzed from 150 to 800 °C with heating rates of 10, 50, and 200 K min(-1). We found for the first time that the heating rate of pyrolysis can significantly change the species of liquid organic compounds produced, but cannot change the gaseous species produced under the same conditions. The contents of produced gas and liquid compounds, most of which were produced at 293-383 °C, are influenced by both the heating rate and temperature of pyrolysis. The results also showed that heterocyclic-N, amine-N, and nitrile-N compounds are obtained from the decomposition of N-compounds in sludge, such as pyrrolic-N, protein-N, amine-N, and pyridinic-N. Heterocyclic-N compounds are the dominant N-containing products, which can be due to the thermochemical decomposition of pyridine-N and pyrrole-N, whereas fewer amine-N compounds are produced during the pyrolysis. A mechanism for the decomposition of N-containing compounds in sludge is proposed based on the obtained data. PMID:25141119

Tian, Ke; Liu, Wu-Jun; Qian, Ting-Ting; Jiang, Hong; Yu, Han-Qing

2014-09-16

2

ORGANIC COMPOUNDS IN FISSION REACTORS. II. THORIO-ORGANIC COMPOUNDS  

Microsoft Academic Search

The advantages of the use of organic liquids in fission reactors to ; minmize corrosion and pressure problems were studied relative to the solution of ; thorium in such fluids. Thorio-organic compounds were prepared from organic ; acids, diketones, and other chelating compounds. Salts of carboxylic and phospho-; organic acids were insoluble. The chelate with dibenzoylmethane was soluble in ;

1960-01-01

3

Semivolatile Organic Compounds (SVOCs) Semivolatile organic compounds (SVOCs) are a group of compounds that includes some  

E-print Network

for years indoors, akin to persistent organic pollutants in the outdoor environment (POPs). Many SVOCs alterSemivolatile Organic Compounds (SVOCs) Background Semivolatile organic compounds (SVOCs products, and additives to materials such as vinyl flooring, furniture, clothing, cookware, food packaging

Iglesia, Enrique

4

PERSISTENT PERFLUORINATED ORGANIC COMPOUNDS  

EPA Science Inventory

Perfluorinated compounds (PFCs) have gained notoriety in the recent past. Global distribution of PFCs in wildlife, environmental samples and humans has sparked a recent increase in new investigations concerning PFCs. Historically PFCs have been used in a wide variety of consume...

5

Photochemical dimerization of organic compounds  

DOEpatents

At least one of selectivity and reaction rate of photosensitized vapor phase dimerizations, including dehydrodimerizations, hydrodimerizations and cross-dimerizations of saturated and unsaturated organic compounds is improved by conducting the dimerization in the presence of hydrogen or nitrous oxide.

Crabtree, Robert H. (Bethany, CT); Brown, Stephen H. (Princeton, NJ); Muedas, Cesar A. (New Haven, CT); Ferguson, Richard R. (Branford, CT)

1992-01-01

6

Extraterrestrial Organic Compounds in Meteorites  

NASA Technical Reports Server (NTRS)

Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

2003-01-01

7

Biomedical Compounds from Marine organisms  

PubMed Central

The Ocean, which is called the ‘mother of origin of life’, is also the source of structurally unique natural products that are mainly accumulated in living organisms. Several of these compounds show pharmacological activities and are helpful for the invention and discovery of bioactive compounds, primarily for deadly diseases like cancer, acquired immuno-deficiency syndrome (AIDS), arthritis, etc., while other compounds have been developed as analgesics or to treat inflammation, etc. The life-saving drugs are mainly found abundantly in microorganisms, algae and invertebrates, while they are scarce in vertebrates. Modern technologies have opened vast areas of research for the extraction of biomedical compounds from oceans and seas.

Jha, Rajeev Kumar; Zi-rong, Xu

2004-01-01

8

Thermodynamics of organic compounds  

NASA Astrophysics Data System (ADS)

This research program consisted of an integrated and interrelated effort of basic and applied research in chemical thermodynamics and thermochemistry. Knowledge of variation of physical and thermodynamic properties with molecular structure was used to select compounds for study that because of high ring strain or unusual steric effects may have good energy characteristics per unit volume or per unit mass and thus be useful in the synthesis of high energy fuels. These materials were synthesized, and their thermodynamic properties were evaluated. In cooperation with researcher at Wright-Patterson Air Force Base, ramjet fuels currently in use were subjected to careful thermodynamic evaluation by measurements of heat capacity, enthalpy of combustion and vapor pressure. During the last year of this effort, seven kerosene-type fuels produced by British Petroleum and seven jet fuels produced from shale oil were studied.

Gammon, B. E.; Smith, N. K.

1982-11-01

9

Volatile Organic Compounds in Uremia  

PubMed Central

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

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

2012-01-01

10

Physiological modelling of organic compounds.  

PubMed

In pharmacokinetic modelling the body is represented as a set of compartments. The characteristics of these compartments are defined either by fitting predetermined mathematical equations to the data ('data-based compartments') or by defining compartments based on the actual biological structure of the animal ('physiologically based compartments'). Physiological models of chemical disposition are developed using these physiologically based compartments. These models then consist of sets of organs or types of tissue compartments whose characteristics are based as far as possible on the anatomy and physiology of the test species. Individual organs or types of tissue are defined with respect to their blood flow, volume, kinetic constants for metabolism, storage capacity for the compound involved, protein binding and other relevant characteristics. Linking these compartments together in a proper anatomical arrangement yields the physiological model for compound disposition. This paper provides an overview of the basics for constructing physiological models for organic compounds, focusing on the structure of individual compartments in these models and the data required for model development. Some past applications of physiological models are reviewed and speculation offered on future developments in this field. PMID:1888102

Andersen, M E

1991-06-01

11

Volatile organic compound sensor system  

DOEpatents

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

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

2011-03-01

12

Electroreduction of Halogenated Organic Compounds  

NASA Astrophysics Data System (ADS)

The electroreductive cleavage of the carbon-halogen bond in halogenated organic compounds has been extensively studied for more than 70 years, since it is prodromal to a large variety of synthetic applications in organic electrochemistry. Over the years the research interest have progressively included the environmental applications, since several organic halocompounds are known to have (or have had) a serious environmental impact because of their (present or past) wide use as cleaning agents, herbicides, cryogenic fluids, reagents (e.g. allyl and vinyl monomers) for large production materials, etc. Recent studies have also demonstrated the wide spread out- and in-door-presence of volatile organic halides, although at low level, in connexion with residential and non-residential (e.g. stores, restaurants and transportation) activities. In this context, the detoxification of emissions to air, water and land by the selective removal of the halogen group represents a valid treatment route, which, although not leading to the complete mineralization of the pollutants, produces less harmful streams to be easily treated by electrochemical or conventional techniques. The electroreduction process is analysed and discussed in terms of electrode material, reaction medium, cell design and operation, and of substrate classification.

Rondinini, Sandra; Vertova, Alberto

13

Volatile organic compound sensing devices  

DOEpatents

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

Lancaster, Gregory D. (Idaho Falls, ID); Moore, Glenn A. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID); Reagen, William K. (Stillwater, MN)

1995-01-01

14

Volatile organic compound sensing devices  

DOEpatents

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

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

1995-08-29

15

Determination of organic compounds in bottled waters  

Microsoft Academic Search

The presence of organic compounds in bottled waters available in the Greek market and their fate when the representative samples exposed at different conditions were the main purposes of this study. The determination of the organic compounds was performed by gas chromatography–mass spectrometry techniques. Disinfection by-products compounds, such as trihalomethanes (THMs) and haloacetic acids (HAAs), were detected at low concentrations

Stavroula V. Leivadara; Anastasia D. Nikolaou; Themistokles D. Lekkas

2008-01-01

16

SORPTION OF HYDROPHOBIC ORGANIC COMPOUNDS BY SEDIMENTS  

EPA Science Inventory

Thermodynamic and kinetic principles which govern the uptake of nonionic, hydrophobic organic chemicals by sediments in aqueous systems are summarized. Sorption onto organic-rich sediments can be modeled as a process where the hydrophobic compound partitions into the organic matt...

17

Thermodynamic properties of organic iodine compounds  

NASA Astrophysics Data System (ADS)

A critical evaluation has been made of the thermodynamic properties reported in the literature for 43 organic iodine compounds in the solid, liquid, or ideal gas state. These compounds include aliphatic, cyclic and aromatic iodides, iodophenols, iodocarboxylic acids, and acetyl and benzoyl iodides. The evaluation has been made on the basis of carbon number systematics and group additivity relations, which also allowed to provide estimates of the thermodynamic properties of those compounds for which no experimental data were available. Standard molal thermodynamic properties at 25 °C and 1 bar and heat capacity coefficients are reported for 13 crystalline, 29 liquid, and 39 ideal gas organic iodine compounds, which can be used to calculate the corresponding properties as a function of temperature and pressure. Values derived for the standard molal Gibbs energy of formation at 25 °C and 1 bar of these crystalline, liquid, and ideal gas organic iodine compounds have subsequently been combined with either solubility measurements or gas/water partition coefficients to obtain values for the standard partial molal Gibbs energies of formation at 25 °C and 1 bar of 32 aqueous organic iodine compounds. The thermodynamic properties of organic iodine compounds calculated in the present study can be used together with those for aqueous inorganic iodine species to predict the organic/inorganic speciation of iodine in marine sediments and petroleum systems, or in the near- and far-field of nuclear waste repositories.

Richard, Laurent; Gaona, Xavier

2011-11-01

18

Organic electronic devices using phthalimide compounds  

DOEpatents

Organic electronic devices comprising a phthalimide compound. The phthalimide compounds disclosed herein are electron transporters with large HOMO-LUMO gaps, high triplet energies, large reduction potentials, and/or thermal and chemical stability. As such, these phthalimide compounds are suitable for use in any of various organic electronic devices, such as OLEDs and solar cells. In an OLED, the phthalimide compounds may serve various functions, such as a host in the emissive layer, as a hole blocking material, or as an electron transport material. In a solar cell, the phthalimide compounds may serve various functions, such as an exciton blocking material. Various examples of phthalimide compounds which may be suitable for use in the present invention are disclosed.

Hassan, Azad M.; Thompson, Mark E.

2012-10-23

19

Organic electronic devices using phthalimide compounds  

DOEpatents

Organic electronic devices comprising a phthalimide compound. The phthalimide compounds disclosed herein are electron transporters with large HOMO-LUMO gaps, high triplet energies, large reduction potentials, and/or thermal and chemical stability. As such, these phthalimide compounds are suitable for use in any of various organic electronic devices, such as OLEDs and solar cells. In an OLED, the phthalimide compounds may serve various functions, such as a host in the emissive layer, as a hole blocking material, or as an electron transport material. In a solar cell, the phthalimide compounds may serve various functions, such as an exciton blocking material. Various examples of phthalimide compounds which may be suitable for use in the present invention are disclosed.

Hassan, Azad M.; Thompson, Mark E.

2010-09-07

20

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

Smith, Jr., Lawrence A. (Houston, TX)

1989-01-01

21

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

Smith, L.A. Jr.

1989-07-18

22

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

Smith, Jr., Lawrence A. (Bellaire, TX); Arganbright, Robert P. (Seabrook, TX); Hearn, Dennis (Houston, TX)

1993-01-01

23

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

1993-09-07

24

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

Smith, Jr., Lawrence A. (Bellaire, TX); Arganbright, Robert P. (Seabrook, TX); Hearn, Dennis (Houston, TX)

1994-01-01

25

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

1994-06-14

26

Microwave spectra of some volatile organic compounds  

NASA Technical Reports Server (NTRS)

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

White, W. F.

1975-01-01

27

(CHINA) PERFLUORINATED ORGANIC COMPOUND EXPOSURE ASSESSMENT RESEARCH  

EPA Science Inventory

A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...

28

Organic compounds passage through RO membranes  

Microsoft Academic Search

Organic solute permeation, sorption, and rejection by reverse osmosis membranes, from aqueous solutions, were studied experimentally and via artificial neural networks (ANN)-based quantitative structure–property relations (QSPR), for a set of fifty organic compounds for polyamide and cellulose acetate membranes. Membrane solute sorption and passage for dead-end filtration model experiments were quantified based on radioactivity measurements for radiolabeled compounds in the

Dan Libotean; Jaume Giralt; Robert Rallo; Yoram Cohen; Francesc Giralt; Harry F. Ridgway; Grisel Rodriguez; Don Phipps

2008-01-01

29

Volatile organic compounds in ambient aerosols  

NASA Astrophysics Data System (ADS)

In order to investigate the concentration levels of volatile organic compounds (VOCs) in ambient aerosols, monocyclic aromatic hydrocarbons (MAHs) and chlorinated hydrocarbons (CHs) in the particulate phase were measured simultaneously with those in the gas phase in the urban atmosphere. Six compounds were detected in the aerosols at concentrations from 0.051 (1,2-dichloroethane) to 1.75 ng m - 3 (benzene). Benzene was detected as the most dominant compound in the aerosols, although toluene was the most dominant compound in the gas phase. The VOCs in the aerosols had concentrations comparable to those reported for some semi-volatile organic compounds (SOCs) in the aerosols. The concentrations of the VOCs in the aerosols were primarily controlled by the aerosol mass loading. Temperature and relative humidity had no significant effect on the gas/particle partitioning of the VOCs. Our results also suggested that the hygroscopic properties of the aerosols should be considered to discuss the partitioning of the VOCs.

Matsumoto, Kiyoshi; Matsumoto, Kumi; Mizuno, Riichi; Igawa, Manabu

2010-07-01

30

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

Smith, Jr., Lawrence A. (Bellaire, TX); Arganbright, Robert P. (Seabrook, TX); Hearn, Dennis (Houston, TX)

1993-01-01

31

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

1993-01-05

32

Air sparging of organic compounds in groundwater  

SciTech Connect

Soils and aquifers containing organic compounds have been traditionally treated by excavation and disposal of the soil and/or pumping and treating the groundwater. These remedial options are often not practical or cost effective solutions. A more favorable alternative for removal of the adsorbed/dissolved organic compounds would be an in situ technology. Air sparging will remove volatile organic compounds from both the adsorbed and dissolved phases in the saturated zone. This technology effectively creates a crude air stripper below the aquifer where the soil acts as the ``packing``. The air stream that contacts dissolved/adsorbed phase organics in the aquifer induces volatilization. A case history illustrates the effectiveness of air sparging as a remedial technology for addressing organic compounds in soil and groundwater. The site is an operating heavy equipment manufacturing facility in central Florida. The soil and groundwater below a large building at the facility was found to contain primarily diesel type petroleum hydrocarbons during removal of underground storage tanks. The organic compounds identified in the groundwater were Benzene, Xylenes, Ethylbenzene and Toluenes (BTEX), Methyl tert-Butyl Ether (MTBE) and naphthalenes in concentrations related to diesel fuel.

Hicks, P.M. [Groundwater Technology, Inc., Tampa, FL (United States)

1994-12-31

33

Reflectance spectroscopy of organic compounds: 1. Alkanes  

USGS Publications Warehouse

Reflectance spectra of the organic compounds comprising the alkane series are presented from the ultraviolet to midinfrared, 0.35 to 15.5 /??m. Alkanes are hydrocarbon molecules containing only single carbon-carbon bonds, and are found naturally on the Earth and in the atmospheres of the giant planets and Saturn's moon, Titan. This paper presents the spectral properties of the alkanes as the first in a series of papers to build a spectral database of organic compounds for use in remote sensing studies. Applications range from mapping the environment on the Earth, to the search for organic molecules and life in the solar system and throughout the. universe. We show that the spectral reflectance properties of organic compounds are rich, with major diagnostic spectral features throughout the spectral range studied. Little to no spectral change was observed as a function of temperature and only small shifts and changes in the width of absorption bands were observed between liquids and solids, making remote detection of spectral properties throughout the solar system simpler. Some high molecular weight organic compounds contain single-bonded carbon chains and have spectra similar to alkanes even ' when they fall into other families. Small spectral differences are often present allowing discrimination among some compounds, further illustrating the need to catalog spectral properties for accurate remote sensing identification with spectroscopy.

Clark, R.N.; Curchin, J.M.; Hoefen, T.M.; Swayze, G.A.

2009-01-01

34

Catalyst for Oxidation of Volatile Organic Compounds  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

35

Analyzing method on biogenic volatile organic compounds  

NASA Astrophysics Data System (ADS)

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

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

2002-02-01

36

Atmospheric transformation of volatile organic compounds  

NASA Astrophysics Data System (ADS)

To be able to understand and predict the concentration of a target compound in the atmosphere one must understand the atmospheric chemistry involved. The transformation of volatile organic compounds in the troposphere is predominantly driven by the interaction with the hydroxyl and nitrate radicals. The hydroxyl radical exists in daylight conditions and its reaction rate constant with an organic compound is typically very fast. The nitrate radical drives the nighttime chemistry. These radicals can scavenge hydrogen from an organic molecule generating secondary products that are often overlooked in detection schemes. Secondary products can be more stable and serve as a better target compound in detection schemes. The gas phase reaction of the hydroxyl radical (OH) with cyclohexanol (COL) has been studied. The rate coefficient was determined to be (19.0 +/- 4.8) X 10-12 cm3 molecule-1 s-1 (at 297 +/- 3 K and 1 atmosphere total pressure) using the relative rate technique with pentanal, decane, and tridecane as the reference compounds. Assuming an average OH concentration of 1 X 106 molecules cm-3, an atmospheric lifetime of 15 h is calculated for cyclohexanol. Products of the OH + COL reaction were determined to more clearly define cyclohexanol's atmospheric degradation mechanism. The observed products were: cyclohexanone, hexanedial, 3- hydroxycyclohexanone, and 4-hydroxycyclohexanone. Consideration of the potential reaction pathways suggest that each of these products is formed via hydrogen abstraction at a different site on the cyclohexanol ring.

Henley, Michael V.; Bradley, William R.; Wyatt, Sheryl E.; Graziano, G. M.; Wells, J. R.

2000-07-01

37

Chlorinated organic compounds in urban river sediments  

SciTech Connect

Among anthropogenic chemicals, many chlorinated organic compounds have been used as insecticides and detected frequently as contaminants in urban river sediments so far. However, the number and total amount of chemicals produced commercially and used are increasing year by year, though each amount of chemicals is not so high. New types of contaminants in the environment may be detected by the use of newly developed chemicals. Chlorinated organic compounds in the urban river sediments around Tokyo and Kyoto, large cities in Japan, were surveyed and recent trends of contaminants were studied. Contaminants of the river sediments in industrial areas had a variety, but PCB (polychlorinated biphenyls) was detected in common in industrial areas. Concentration of PCB related well to the number of factories on both sides of rivers, although the use of PCB was stopped 20 years ago. In domestic areas, Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) and Triclocarban (3,4,4{prime}-trichlorocarbanilide)(both are contained in soap or shampoo for fungicides), p-dichlorobenzene (insecticides for wears) and TCEP(tris-chloroethyl phosphate) were detected. EOX(extracted organic halogen) in the sediments was 5 to 10 times of chlorinated organic compounds detected by GC/MS. Major part of organic halogen was suggested to be included in chlorinated organics formed by bleaching or sterilization.

Soma, Y.; Shiraishi, H.; Inaba, K. [National Inst. of Environmental Studies, Tsukuba, Ibaraki (Japan)

1995-12-31

38

Measurement of volatile organic compounds inside automobiles†  

Microsoft Academic Search

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

Marion J Fedoruk; Brent D Kerger

2003-01-01

39

Azodicarboxylates: synthesis and functionalization of organic compounds  

NASA Astrophysics Data System (ADS)

The data on transformations of dialkyl azodicarboxylates and their analogues involving various substrates are generalized. Nucleophilic addition and oxidation, pericyclic reactions and reactions occurring under the Mitsunobu reaction conditions are considered. Ample opportunities for application of these compounds in fine organic synthesis are shown. The bibliography includes 245 references. Dedicated to Academician B A Trofimov on the occasion of his 75th birthday.

Zhirov, A. M.; Aksenov, A. V.

2014-06-01

40

Catalytic Destruction Of Toxic Organic Compounds  

NASA Technical Reports Server (NTRS)

Proposed process disposes of toxic organic compounds in contaminated soil or carbon beds safely and efficiently. Oxidizes toxic materials without producing such other contaminants as nitrogen oxides. Using air, fuel, catalysts, and steam, system consumes less fuel and energy than decontamination processes currently in use. Similar process regenerates carbon beds used in water-treatment plants.

Voecks, Gerald E.

1990-01-01

41

Global Exposure Modelling of Semivolatile Organic Compounds  

NASA Astrophysics Data System (ADS)

Organic compounds which are persistent and toxic as the agrochemicals ?-hexachlorocyclohexane (?-HCH, lindane) and dichlorodiphenyltrichloroethane (DDT) pose a hazard for the ecosystems. These compounds are semivolatile, hence multicompartmental substances and subject to long-range transport (LRT) in atmosphere and ocean. Being lipophilic, they accumulate in exposed organism tissues and biomagnify along food chains. The multicompartmental global fate and LRT of DDT and lindane in the atmosphere and ocean have been studied using application data for 1980, on a decadal scale using a model based on the coupling of atmosphere and (for the first time for these compounds) ocean General Circulation Models (ECHAM5 and MPI-OM). The model system encompasses furthermore 2D terrestrial compartments (soil and vegetation) and sea ice, a fully dynamic atmospheric aerosol (HAM) module and an ocean biogeochemistry module (HAMOCC5). Large mass fractions of the compounds are found in soil. Lindane is also found in comparable amount in ocean. DDT has the longest residence time in almost all compartments. The sea ice compartment locally almost inhibits volatilization from the sea. The air/sea exchange is also affected , up to a reduction of 35 % for DDT by partitioning to the organic phases (suspended and dissolved particulate matter) in the global oceans. Partitioning enhances vertical transport in the sea. Ocean dynamics are found to be more significant for vertical transport than sinking associated with particulate matter. LRT in the global environment is determined by the fast atmospheric circulation. Net meridional transport taking place in the ocean is locally effective mostly via western boundary currents, upon applications at mid- latitudes. The pathways of the long-lived semivolatile organic compounds studied include a sequence of several cycles of volatilisation, transport in the atmosphere, deposition and transport in the ocean (multihopping substances). Multihopping is more significant for DDT than for lindane. It enhances the LRT potential for both compounds.

Guglielmo, F.; Lammel, G.; Maier-Reimer, E.

2008-12-01

42

Sonochemical degradation of chlorinated organic compounds, phenolic compounds and organic dyes - a review.  

PubMed

Sonochemical processes have been widely used in chemistry and chemical engineering field. Recently, these processes have found new applications in the environmental field, because of advantages in terms of operational simplicity, secondary pollutant formation and safety. Several studies have reported on sonochemical degradation of organic compounds that are toxic in nature. The objective of this review was to identify and examine some of the studies on sonochemical degradation of chlorinated organic compounds, phenolic compounds and organic dyes. This review also examines the basic theory of sonochemical reactions and the use of sonochemical reactors for environmental applications. PMID:19200588

Chowdhury, Pankaj; Viraraghavan, T

2009-04-01

43

Nonvolatile organic compounds in treated waters.  

PubMed Central

Over the past decade much information has been published on the analysis of organics extracted from treated water. Certain of these organics have been shown to be by-products of the chlorination disinfection process and to possess harmful effects at high concentrations. This has resulted in increased interest in alternative disinfection processes, particularly ozonation. The data on organics had been largely obtained by using gas chromatography-mass spectrometry, which is only capable of analyzing, at best, 20% of the organics present in treated water. Research in key areas such as mutagenicity testing of water and characterization of chlorination and ozonation by-products has emphasized the need for techniques suitable for analysis of the remaining nonvolatile organics. Several methods for the isolation of nonvolatile organics have been evaluated and, of these, freeze-drying followed by methanol extraction appears the most suitable. Reverse-phase HPLC was used for separation of the methanol extract, but increased resolution for separation of the complex mixtures present is desirable. In this context, high resolution size exclusion chromatography shows promise. Characterization of separated nonvolatiles is possible by the application of state-of-the-art mass spectrometric techniques. Results obtained by these techniques have shown that the nonvolatile organic fraction of chlorinated drinking water consists of many discrete compounds. Among these, some of the chlorinated compounds are almost certainly by-products of disinfection. Studies of the by-products of ozonation of fulvic and humic acids isolated from river waters have indicated a similar proportion of nonvolatile organics. Further, ozonation can result in the release of compounds that are trapped in the macromolecules. PMID:6759110

Watts, C D; Crathorne, B; Fielding, M; Killops, S D

1982-01-01

44

Organic photosensitive devices using subphthalocyanine compounds  

DOEpatents

An organic photosensitive optoelectronic device, having a donor-acceptor heterojunction of a donor-like material and an acceptor-like material and methods of making such devices is provided. At least one of the donor-like material and the acceptor-like material includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound; and/or the device optionally has at least one of a blocking layer or a charge transport layer, where the blocking layer and/or the charge transport layer includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound.

Rand, Barry (Princeton, NJ); Forrest, Stephen R. (Ann Arbor, MI); Mutolo, Kristin L. (Hollywood, CA); Mayo, Elizabeth (Alhambra, CA); Thompson, Mark E. (Anaheim Hills, CA)

2011-07-05

45

Toxic organic compounds from energy production  

SciTech Connect

The US Department of Energy's Office of Health and Environmental Research (OHER) has supported work in our laboratory since 1977. The general theme of this program has been the identification of potentially toxic organic compounds associated with various combustion effluents, following the fates of these compounds in the environment, and improving the analytical methodology for making these measurements. The projects currently investigation include: an improved sampler for semi-volatile compounds in the atmosphere; the wet and dry deposition of dioxins and furans from the atmosphere; the photodegradation and mobile sources of dioxins and furans; and the bioaccumulation of PAH by tree bark. These projects are all responsive to OHER's interest in the pathways and mechanisms by which energy-related agents move through and are modified by the atmosphere''. The projects on gas chromatographic and liquid chromatographic tandem mass spectrometry are both responsive to OHER's interest in new and more sensitive technologies for chemical measurements''. 35 refs., 9 figs.

Hites, R.A.

1991-09-20

46

Microbiological degradation of atmospheric organic compounds  

NASA Astrophysics Data System (ADS)

Until now, aerosol transformation was assumed to be via chemical or physical processes. Here we present evidence that an important class of organic aerosols - dicarboxylic acids (DCA) - can be efficiently transformed by existing airborne microbes (bacteria and fungi) in the boundary layer. Isotopic studies indicate that microbiological entities transform and use DCA as nutrients. Several observed products are toxicants or pathogens. Identified volatile products indicate that DCA can be recycled back to the atmosphere via microbiological processes. Thus, biodegradation could be an important atmospheric transformation pathway for organic compounds.

Ariya, Parisa A.; Nepotchatykh, Oleg; Ignatova, Olga; Amyot, Marc

2002-11-01

47

Organic Compounds in Star Forming Regions  

NASA Astrophysics Data System (ADS)

The influence of complex dust composition on the general chemical evolution of a prestellar core and the content of complex organic compounds is studied. It is shown that various component groups respond differently to the presence of a small dust population. At early stages the difference is determined primarily by changes in the balance of photo processes due to effective absorption of ultraviolet photons by small dust grains of the second population and collisional reactions with dust particles. At later stages differences are also caused by the growing dominance of additional reaction channels related to surface organic synthesis.

Kochina, O.; Wiebe, D.

2014-09-01

48

Metabolic Reactions among Organic Sulfur Compounds  

NASA Technical Reports Server (NTRS)

Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. Numerous authors have addressed the energy available from a variety of inorganic sulfur redox pairs. Less attention has been paid, however, to the energy required or gained from metabolic reactions among organic sulfur compounds. Work in this area has focused on the oxidation of alkyl sulfide or disulfide to thiol and formaldehyde, e.g. (CH3)2S + H2O yields CH3SH + HCHO + H2, eventually resulting in the formation of CO2 and SO4(-2). It is also found that reactions among thiols and disulfides may help control redox disequilibria between the cytoplasm and the periplasm. Building on our earlier efforts for thiols, we have compiled and estimated thermodynamic properties for alkyl sulfides. We are investigating metabolic reactions among various sulfur compounds in a variety of extreme environments, ranging from sea floor hydrothermal systems to organic-rich sludge. Using thermodynamic data and the revised HKF equation of state, along with constraints imposed by the geochemical environments sulfur-metabolizing organisms inhabit, we are able to calculate the amount of energy available to these organisms.

Schulte, M.; Rogers, K.

2005-01-01

49

Surface ionization mass spectrometry of organic compounds Part 4. Oxygen-containing organic compounds  

Microsoft Academic Search

Surface ionization organic mass spectrometry (SIOMS) was performed for 42 oxygen-containing organic compounds not previously investigated, using a quadrupole mass spectrometer in which the thermionic ion source has a rhenium oxide emitter. The results are interpreted in terms of the modes of ion formation: molecular surface ionization, dissociative surface ionization and associative surface ionization. SIOMS is particularly well suited to

Toshihiro Fujii; Kouichi Kakizaki; Yoshihiro Mitsutsuka

1991-01-01

50

Self assembly properties of primitive organic compounds  

NASA Technical Reports Server (NTRS)

A central event in the origin of life was the self-assembly of amphiphilic, lipid-like compounds into closed microenvironments. If a primitive macromolecular replicating system could be encapsulated within a vesicular membrane, the components of the system would share the same microenvironment, and the result would be a step toward true cellular function. The goal of our research has been to determine what amphiphilic molecules might plausibly have been available on the early Earth to participate in the formation of such boundary structures. To this end, we have investigated primitive organic mixtures present in carbonaceous meteorites such as the Murchison meteorite, which contains 1-2 percent of its mass in the form of organic carbon compounds. It is likely that such compounds contributed to the inventory of organic carbon on the prebiotic earth, and were available to participate in chemical evolution leading to the emergence of the first cellular life forms. We found that Murchison components extracted into non-polar solvent systems are surface active, a clear indication of amphiphilic character. One acidic fraction self-assembles into vesicular membranes that provide permeability barriers to polar solutes. Other evidence indicates that the membranes are bimolecular layers similar to those formed by contemporary membrane lipids. We conclude that bilayer membrane formation by primitive amphiphiles on the early Earth is feasible. However, only a minor fraction of acidic amphiphiles assembles into bilayers, and the resulting membranes require narrowly defined conditions of pH and ionic composition to be stable. It seems unlikely, therefore, that meteoritic infall was a direct source of membrane amphiphiles. Instead, the hydrocarbon components and their derivatives more probably would provide an organic stock available for chemical evolution. Our current research is directed at possible reactions which would generate substantial quantities of membranogenic amphiphiles. One possibility is photochemical oxidation of hydrocarbons.

Deamer, D. W.

1991-01-01

51

Molecular Characterization of S- and N-containing Organic Constituents in Ambient Aerosols by negative ion mode High-Resolution Nanospray Desorption Electrospray Ionization Mass Spectrometry: CalNex 2010 field study  

SciTech Connect

Samples of ambient aerosols from the 2010 California Research at the Nexus of Air Quality and Climate Change (CalNex) field study were analyzed using Nanospray Desorption Electrospray Ionization High Resolution Mass Spectrometry (nano-DESI/MS). Four samples per day were collected in Bakersfield, CA on June 20-24 with a collection time of 6 hours per sample. Four characteristic groups of organic constituents were identified in the samples: compounds containing carbon, hydrogen, and oxygen only (CHO), sulfur- (CHOS), nitrogen-(CHON), and both nitrogen- and sulfur-containing organics (CHONS). Within the groups, organonitrates, organosulfates, and nitroxy organosulfates were assigned based on accurate mass measurements and elemental ratio comparisons. Changes in the chemical composition of the aerosol samples were observed throughout the day. The number of observed CHO compounds increased in the afternoon samples, suggesting regional photochemical processing as a source. The average number of CHOS compounds had the smallest changes throughout the day, consistent with a more broadly distributed source. Both of the nitrogen-containing groups (CHON and CHONS) had greater numbers of compounds in the night and morning samples, indicating that nitrate radical chemistry was likely a source for those compounds. Most of the compounds were found in submicron particles. The size distribution of CHON compounds was bimodal. We conclude that the majority of the compounds observed were secondary in nature with both biogenic and anthropogenic sources.

O'Brien, Rachel E.; Laskin, Alexander; Laskin, Julia; Rubitschun, Caitlin L.; Surratt, Jason D.; Goldstein, Allen H.

2014-11-19

52

Palladium catalyzed hydrogenation of bio-oils and organic compounds  

SciTech Connect

The invention provides palladium-catalyzed hydrogenations of bio-oils and certain organic compounds. Experimental results have shown unexpected and superior results for palladium-catalyzed hydrogenations of organic compounds typically found in bio-oils.

Elliott, Douglas C. (Richland, WA); Hu, Jianli (Kennewick, WA); Hart, Todd R. (Kennewick, WA); Neuenschwander, Gary G. (Burbank, WA)

2008-09-16

53

Biogenic volatile organic compounds - small is beautiful  

NASA Astrophysics Data System (ADS)

While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to <2m above ground level. Emissions at leaf scale are well documented and widely presented, and are not discussed here. Instead we describe some details of recent research on rhizosphere bVOCs, and bVOCs associated with pollination of flowers. Although bVOC emissions from soil surfaces are small, bVOCs are exuded by roots of some plant species, and can be extracted from decaying litter. Naturally occurring monoterpenes in the rhizosphere provide a specialised carbon source for micro-organisms, helping to define the micro-organism community structure, and impacting on nutrient cycles which are partly controlled by microorganisms. Naturally occurring monoterpenes in the soil system could also affect the aboveground structure of ecosystems because of their role in plant defence strategies and as mediating chemicals in allelopathy. A gradient of monoterpene concentration was found in soil around Pinus sylvestris and Pinus halepensis, decreasing with distance from the tree. Some compounds (?-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, ?-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-?-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 morning and raised in the afternoon. This is reversed for the "cataflexistyle" morphology. The bVOC mixture emitted by each morphology in morning and afternoon was complex. However for compounds showing a difference (cis-ocimene and Z + E epoxy -ocimene), the emissions from the anaflexistyle were greater than from the cataflexistyle, and were greater in the afternoon compared with the morning emissions. Where large flowering plant species are abundant, big changes in monoterpene emissions at < 2m above ground level over relatively small periods of time during pollination are likely to be missed in larger scale integrated flux measurements.

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

2012-12-01

54

Volatile Organic Compound Analysis in Istanbul  

NASA Astrophysics Data System (ADS)

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, Ni?anta??, 34365, ?stanbul, Turkey. One of the major problems of megacities is air pollution. Therefore, investigations of air quality are increasing and supported by many institutions in recent years. Air pollution in Istanbul contains many components that originate from a wide range of industrial, heating, motor vehicle, and natural emissions sources. VOC, originating mainly from automobile exhaust, secondhand smoke and building materials, are one of these compounds containing some thousands of chemicals. In spite of the risks to human health, relatively little is known about the levels of VOC in Istanbul. In this study, ambient air quality measurements of 32 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in Ka??thane (Golden Horn) region in Istanbul during the winter season of 2011 in order to develop the necessary scientific framework for the subsequent developments. Ka??thane creek valley is the source part of the Golden Horn and one of the most polluted locations in Istanbul due to its topographical form and pollutant sources in the region. In this valley, horizontal and vertical atmospheric motions are very weak. The target compounds most commonly found were benzene, toluene, xylene and ethyl benzene. Concentrations of total hydrocarbons ranged between 1.0 and 10.0 parts per billion, by volume (ppbv). Ambient air levels of halogenated hydrocarbons appeared to exhibit unique spatial variations and no single factor seemed to explain trends for this group of compounds. N-octane, 3-methylheptane, n-nonane, 2,3,4-trimethylpentane and n-hexane parameters ranged between 3 ppbv and maximum value of 10 ppbv. The other VOC parameters are measured below 3 ppbv value. At participating urban locations for the year of data considered, levels of carbonyls were higher than the level of the other organic compound groups, suggesting that emissions from motor vehicles and photochemical reactions strongly in?uence ambient air concentrations of carbonyls. Of the most prevalent carbonyls, formaldehyde and acetaldehyde were the dominant compounds, ranging from 1.5-7.4 ppbv for formaldehyde, to 0.8-2.7 ppbv for acetaldehyde. Keywords: Air quality, Volatile Organic Compounds (VOC), industry, meteorology, urban, Ka??thane, ?stanbul. Acknowledgment: This work was part of the TUJJB-TUMEHAP-01-10 and Turkish Scientific and Technical Research Council Project No: 109Y132.

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

2012-04-01

55

Measurement of volatile organic compounds inside automobiles.  

PubMed

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. PMID:12595882

Fedoruk, Marion J; Kerger, Brent D

2003-01-01

56

Alkaline dechlorination of chlorinated volatile organic compounds  

SciTech Connect

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

Gu, B.; Siegrist, R.L.

1996-06-01

57

Catalytic destruction of organic volatile nitrogen compounds  

SciTech Connect

A family of catalysts has been identified for purification of industrial gas streams which are contaminated with odorous and/or toxic volatile nitrogen compounds (VNC). Temperature-conversion curves were measured for destruction of a series of organic VNC`s in moist air at 15,000 hr {sup {minus}1} gas hourly space velocity (STP), and the yields of N{sub 2}, N{sub 2}O, and total NO{sub x} (NO + NO{sub 2}) were measured. The VNCs of interest included primary, secondary and tertiary amines, ethylenediamine, ethanolamine, acetonitrile, dimethylfomamide, pyridine, piperidine and aniline. The ease of destruction of these compounds over a monolithic platinum VNC catalyst as reflected in the temperature required or 95% conversion, ranged from n-propylamine (234{degrees}C) to acetonitrile (343{degrees}C). Selectivity to N{sub 2} plus N{sub 2}O at the temperatures of 95% conversion decreased with increasing T-95 from 93% to 46%. Additional studies were done with triethylamine at several space velocities with the VNC catalyst and with some related PT catalysts. The results of these tests suggest that N{sub 2}, N{sub 2}O, and NO{sub x} (NO + NO{sub 2}) are formed by at least three competitive reaction pathways.

Lester, G.R.; Homeyer, S.T. [Allied Signal Inc., Des Plaines, IL (United States)

1993-12-31

58

GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FORM ANTHROPOGENIC SOURCES  

EPA Science Inventory

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

59

ACUTE TOXICITY OF SELECTED ORGANIC COMPOUNDS TO FATHEAD MINNOWS  

EPA Science Inventory

Static nonrenewal laboratory bioassays were conducted with 26 organic compounds commonly used by industry. The selected compounds represented the five following chemical classes: acids, alcohols, hydrocarbons, ketones and aldehydes, and phenols. Juvenile fathead minnows (Pimephal...

60

BIODEGRADATION AND CARBON ADSORPTION CARCINOGENIC AND HAZARDOUS ORGANIC COMPOUNDS  

EPA Science Inventory

This research program was conducted to determine the capability of biological treatment and activated carbon adsorption to remove chemical carcinogens and other hazardous organic compounds from water and wastewater. Compounds studied were benzidine, 4-nitrobiphenyl, 3,3'-dichloro...

61

Soluble organic compounds in the Tagish Lake meteorite  

NASA Astrophysics Data System (ADS)

The C2 ungrouped Tagish Lake meteorite preserves a range of lithologies, reflecting variable degrees of parent-body aqueous alteration. Here, we report on soluble organic compounds, including aliphatic and aromatic hydrocarbons, monocarboxylic acids, and amino acids, found within specimens representative of the range of aqueous alteration. We find that differences in soluble organic compounds among the lithologies may be explained by oxidative, fluid-assisted alteration, primarily involving the derivation of soluble organic compounds from macromolecular material. In contrast, amino acids probably evolved from precursor molecules, albeit in parallel with other soluble organic compounds. Our results demonstrate the role of parent-body alteration in the modification of organic matter and generation of prebiotic compounds in the early solar system, and have implications for interpretation of the complement of soluble organic compounds in carbonaceous chondrites.

Hilts, Robert W.; Herd, Christopher D. K.; Simkus, Danielle N.; Slater, Greg F.

2014-04-01

62

Method and reaction pathway for selectively oxidizing organic compounds  

DOEpatents

A method of selectively oxidizing an organic compound in a single vessel comprises: a) combining an organic compound, an acid solution in which the organic compound is soluble, a compound containing two oxygen atoms bonded to one another, and a metal ion reducing agent capable of reducing one of such oxygen atoms, and thereby forming a mixture; b) reducing the compound containing the two oxygen atoms by reducing one of such oxygen atoms with the metal ion reducing agent to, 1) oxidize the metal ion reducing agent to a higher valence state, and 2) produce an oxygen containing intermediate capable of oxidizing the organic compound; c) reacting the oxygen containing intermediate with the organic compound to oxidize the organic compound into an oxidized organic intermediate, the oxidized organic intermediate having an oxidized carbon atom; d) reacting the oxidized organic intermediate with the acid counter ion and higher valence state metal ion to bond the acid counter ion to the oxidized carbon atom and thereby produce a quantity of an ester incorporating the organic intermediate and acid counter ion; and e) reacting the oxidized organic intermediate with the higher valence state metal ion and water to produce a quantity of alcohol which is less than the quantity of ester, the acid counter ion incorporated in the ester rendering the carbon atom bonded to the counter ion less reactive with the oxygen containing intermediate in the mixture than is the alcohol with the oxygen containing intermediate.

Camaioni, Donald M. (Richland, WA); Lilga, Michael A. (Richland, WA)

1998-01-01

63

Breath measurements as volatile organic compound biomarkers.  

PubMed Central

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

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

1996-01-01

64

Molecular Models of Volatile Organic Compounds  

NSDL National Science Digital Library

This month's Featured Molecules come from the Report from Other Journals column, Nature: Our Atmosphere in the Year of Planet Earth, and the summary found there of the paper by Lelieveld et al. (1, 2) Added to the collection are several volatile organic compounds (VOCs) that are emitted by a variety of plants. The term VOCs is a common one in environmental chemistry, and is interpreted quite broadly, typically referring to any organic molecule with a vapor pressure sufficiently high to allow for part-per-billion levels in the atmosphere. Common VOCs include methane (the most prevalent VOC), benzene and benzene derivatives, chlorinated hydrocarbons, and many others. The source may be natural, as in the case of the plant emissions, or anthropogenic, as in the case of a molecule such as the gasoline additive methyl tert-butyl ether (MTBE).The oxidation of isoprene in the atmosphere has been a source of interest for many years. Several primary oxidation products are included in the molecule collection, although a number of isomeric forms are also possible (3).The area of VOCs provides innumerable topics for students research papers and projects at all levels of the curriculum from high-school chemistry through the undergraduate courses in chemistry and environmental science. Along the way students have the opportunity for exposure to fields such as epidemiology and toxicology, that may be new to them, but are of increasing importance in the environmental sciences. The MTBE story is an interesting one for students to discover, as it once again emphasizes the role that unintended consequences play in life. An exploration of the sources, structures, reactivity, health and environmental effects and ultimate fate of various VOCs reinforces in students minds just how interconnected the chemistry of the environment is, a lesson that bears repeating frequently.

65

Oceanic protection of prebiotic organic compounds from UV radiation  

NASA Technical Reports Server (NTRS)

It is frequently stated that UV light would cause massive destruction of prebiotic organic compounds because of the absence of an ozone layer. The elevated UV flux of the early sun compounds this problem. This applies to organic compounds of both terrestrial and extraterrestrial origin. Attempts to deal with this problem generally involve atmospheric absorbers. We show here that prebiotic organic polymers as well as several inorganic compounds are sufficient to protect oceanic organic molecules from UV degradation. This aqueous protection is in addition to any atmospheric UV absorbers and should be a ubiquitous planetary phenomenon serving to increase the size of planetary habitable zones.

Cleaves, H. J.; Miller, S. L.; Bada, J. L. (Principal Investigator)

1998-01-01

66

[Quantification assessment of the relationship between chemical and olfactory concentrations for malodorous volatile organic compounds].  

PubMed

Using self-made cold-traps and gas bags, the odor samples were collected from 6 sewage treatment workshops of a typical municipal sewage treatment plant in Guangzhou City. The chemical composition and olfactory concentrations of these samples were respectively analyzed by thermal-desorption/GC-MS and triangle odor bag method. Finally, a mathematical equation was built for assessing the relationship between principal organic odorants and the olfactory concentrations. The result showing that: (1) More than 70 volatile organic compounds were detected in municipal sewage treatment plant, among which were 30 malodorous volatile organic compounds (MVOCs), ranging from 0.37 to 1 872.24 microg x m(-3) and appearing in sludge dewatering, thickening and aeration tank with the highest concentrations. (2) Principle component analysis was used to group the target MVOCs into 5 categories: benzenes, halohydrocarbons, aldehydes, hydrocarbons and S, N-containing organic compounds. (3) Multiple lineal regression analysis was used to build a quantified relationship between chemical and olfactory concentrations of MVOCs. The result indicated that 25% of the odor problem of sewage treatment unit was due to MVOCs. The predicted values were fitting well with measured values. The sensitivity of mathematical equation for measuring odor concentration was higher than that of human olfactory system. PMID:22468522

Liu, Shu-Le; Wang, Bo-Guang; He, Jie; Tang, Xiao-Dong; Zhao, De-Jun; Guo, Wei

2011-12-01

67

Volatile organic compound remedial action project  

SciTech Connect

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

NONE

1991-12-01

68

Microwave process for volatile organic compound abatement.  

PubMed

The CHA Corporation has completed the U.S. Air Force Phase II Small Business Innovation Research program to investigate the feasibility of using a novel microwave-based process for the removal and destruction of volatile organic compounds (VOCs) in effluents from noncombustion sources, such as paint booth ventilation streams. Removal of solvents by adsorption, followed by the regeneration of saturated granular activated carbon (GAC) by microwave energy, was achieved in a single fixed-bed reactor. Microwave regeneration of the fixed-bed-saturated carbon restored the original GAC adsorption capacity. After 20 adsorption/regeneration cycles, the adsorption capacity dropped from 13.5 g methyl ethyl ketone (MEK)/100 g GAC to 12.5 g MEK/100 g GAC. During microwave regeneration of the GAC fixed bed, the concentrated desorbed paint solvent was oxidized by passing the solvent mixture through a fixed bed of an oxidation catalyst mixed with silicon carbide in a microwave reactor. A 98% oxidation efficiency was consistently achieved from the oxidation of VOCs in the microwave catalytic reactor. PMID:15666467

Cha, C Y; Carlisle, C T

2001-12-01

69

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS  

SciTech Connect

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

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

2002-06-01

70

Nitrated Secondary Organic Tracer Compounds in Biomass Burning Smoke  

NASA Astrophysics Data System (ADS)

Natural and human-initiated biomass burning releases large amounts of gases and particles into the atmosphere, impacting climate, environment and affecting public health. Several hundreds of compounds are emitted from biomass burning and these compounds largely originate from the pyrolysis of biopolymers such as lignin, cellulose and hemicellulose. Some of compounds are known to be specific to biomass burning and widely recognized as tracer compounds that can be used to identify the presence of biomass burning PM. Detailed chemical analysis of biomass burning influenced PM samples often reveals the presence compounds that correlated well with levoglucosan, a known biomass burning tracer compound. In particular, nitrated aromatic compounds correlated very well with levoglucosan, indicating that biomass burning as a source for this class of compounds. In the present study, we present evidence for the presence of biomass burning originating secondary organic aerosol (BSOA) compounds in biomass burning influenced ambient PM. These BSOA compounds are typically nitrated aromatic compounds that are produced in the oxidation of precursor compounds in the presence of NOx. The precursor identification was performed from a series of aerosol chamber experiments. m-Cresol, which is emitted from biomass burning at significant levels, is found to be a major precursor compounds for nitrated BSOA compounds found in the ambient PM. We estimate that the total concentrations of these compounds in the ambient PM are comparable to biogenic SOA compounds in winter months, indicating the BSOA contributes important amounts to the regional organic aerosol loading.

Iinuma, Y.; Böge, O.; Gräfe, R.; Herrmann, H.

2010-12-01

71

POTENTIAL EMISSIONS OF HAZARDOUS ORGANIC COMPOUNDS FROM SEWAGE SLUDGE INCINERATION  

EPA Science Inventory

Laboratory thermal decomposition studies were undertaken to evaluate potential organic emissions from sewage sludge incinerators. Precisely controlled thermal decomposition experiments were conducted on sludge spiked with mixtures of hazardous organic compounds, on the mixtures o...

72

Prioritizing testing of organic compounds detected as gas phase air pollutants: structure-activity study for human contact allergens.  

PubMed Central

Organic compounds that are used or generated anthropogenically in large quantities in cities can be identified through their presence in the urban atmosphere and in air pollutant source emissions. Compounds identified by this method were screened to evaluate their potential to act as contact allergens. The CASE and MULTICASE computer programs, which are based on the detection of structure-activity relationships (SAR), were used to evaluate this potential. These relationships first are determined by comparing chemical structures to biological activity within a learning set comprised of 458 compounds, each of which had been tested experimentally in human trials for its sensitization potential. Using the information contained in this learning set, CASE and MULTICASE predicted the activity of 238 compounds found in the atmosphere for their ability to act as contact allergens. The analysis finds that 21 of 238 compounds are predicted to be active contact allergens (probability >0.5), with potencies ranging from mild to very strong. The compounds come from chemical classes that include chlorinated aromatics and chlorinated hydrocarbons, N-containing compounds, phenols, alkenes, and an S-containing compound. Using the measured airborne concentrations or emission rates of these compounds as an indication of the extent of their use, together with their predicted potencies, provides an efficient method to prioritize the experimental assessment of contact sensitization of untested organic compounds that can be detected as air pollutants. Images Figure 1. PMID:9300925

Johnson, R; Macina, O T; Graham, C; Rosenkranz, H S; Cass, G R; Karol, M H

1997-01-01

73

Secondary organic aerosol from biogenic volatile organic compound mixtures  

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

74

SORPTION OF ORGANIC ACID COMPOUNDS TO SEDIMENTS: INITIAL MODEL DEVELOPMENT  

EPA Science Inventory

The adsorption to sediments and soils of selected organic acid compounds was examined as a function of compound and sediment properties. ntrinsic compound properties examined included the dissociation constant (pKa) and hydrophobic character. roperties of the sediment examined in...

75

Destruction of volatile organic compounds via catalytic incineration (journal version)  

Microsoft Academic Search

This paper gives results of an investigation of the effect of catalytic incinerator design and operation on the destruction of specific volatile organic compounds (VOCs), both singly and in mixtures. A range of operating and design parameters were tested on a wide variety of compounds and compound mixtures. Conclusions of the study, presented here as applying only to the test

M. A. Palazzolo; B. A. Tichenor

1987-01-01

76

Destruction of volatile organic compounds via catalytic incineration  

Microsoft Academic Search

The paper gives results of an investigation of the effect of catalytic-incinerator design and operation the destruction of specific volatile organic compounds (VOCs), both singly and in mixtures. A range of operating and design parameters were tested on a wide variety of compounds and compound mixtures. Conclusions of the study, presented here as applying only to the test catalyst and

B. A. Tichenor; M. A. Palazzolo

1985-01-01

77

High Arctic Biogenic Volatile Organic Compound emissions  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

78

REACTIVITY OF NITROGENOUS AND OTHER ORGANIC COMPOUNDS WITH AQUEOUS CHLORINE  

EPA Science Inventory

A protocol for determining the chlorine demand of organic compounds was developed and tested. Organics were reacted with chlorine at mole ratios of 1:05, 1:1, and 1:3 at pH values of 6, 7, and 8 over a one week period. Compounds tested were drawn mainly from the EPA Register of O...

79

Presence and Distribution of Organic Wastewater Compounds in Wastewater,  

E-print Network

Presence and Distribution of Organic Wastewater Compounds in Wastewater, Surface, Ground.W., Meyer, M.T., and Zaugg, S.D., 2004, Presence and distri- bution of organic wastewater compounds in wastewater, surface, ground, and drinking waters, Minnesota, 2000-02: U.S. Geological Survey Scientific

80

METHODS FOR THE DETERMINATION OF ORGANIC COMPOUNDS IN DRINKING WATER  

EPA Science Inventory

Thirteen analytical methods for the identification and measurement of organic compounds in drinking water are described in detail. ix of the methods are for volatile organic compounds (VOC's) and certain disinfection byproducts and these methods were cited in the Federal Register...

81

TEMPORAL VARIABILITY MEASUREMENT OF SPECIFIC VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

Methodology was developed to determine unambiguously trace levels of volatile organic compounds as they vary in concentration over a variety of time scales. his capability is important because volatile organic compounds (VOCs) are usually measure by time-integrative techniques th...

82

Organic--Inorganic Layer Compounds: Physical Properties and Chemical Reactions  

Microsoft Academic Search

In contrast with intercalation compounds, which can exist both with and without organic molecules between the planes of inorganic material, `molecular composite' compounds have organic groups covalently or ionically bound to inorganic layers. In such crystals the aim is to combine magnetic or optical properties characteristic of the inorganic solid state, like magnetism and luminescence, with properties found in the

P. Day

1985-01-01

83

A Systematic Presentation of Organic Phosphorus and Sulfur Compounds.  

ERIC Educational Resources Information Center

Because the names, interrelations, and oxidation levels of the organic compounds of phosphorus and sulfur tend to confuse students, a simple way to organize these compounds has been developed. The system consists of grouping them by oxidation state and extent of carbon substitution. (JN)

Hendrickson, James B.

1985-01-01

84

Volatile organic compound sources for Southern Finland  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) have several sources, both biogenic and anthropogenic. Emissions of biogenic VOCs in a global scale are estimated to be an order of magnitude higher than anthropogenic ones. However, in densely populated areas and during winter time the anthropogenic VOC emissions dominate over the biogenic ones. The aim of this study was to clarify potential local sources and source areas of VOCs in different seasons. Diurnal behaviour in winter and spring were also compared at two different sites in Finland: SMEAR II and III (Station for Measuring Ecosystem - Atmosphere Relations). SMEAR II is a rural site located in Hyytiälä in Southern Finland 220 km North-West from Helsinki whereas SMEAR III is background urban site located 5 km from the downtown of Helsinki. The volume mixing ratios of VOCs were measured with a proton-transfer-reaction mass spectrometer (PTR-MS, Ionicon Analytik GmbH, Austria) during years 2006-2011. Other trace gases such as CO, NOXand SO2 were also measured in both sites and used for source analysis. Source areas for long term VOC measurements were investigated with trajectory analysis and sources for local and regional concentrations were determined by Unmix multivariate receptor model. Forest fires affect air quality and the biggest smoke plumes can be seen in satellite images and even hinder visibility in the plume areas. They provide temporally and spatially well-defined sources that can be used to verify source area estimates. During the measurement periods two different forest fire episodes with several hotspots, happened in Russia. Forest fires which showed up in these measurements were in 2006 near the border of Finland in Vyborg area and 2010 in Moscow area. Forest fire episodes were clearly observed in trajectory analysis for benzene, toluene and methanol and also CO and NOX. In addition to event sources continuous source areas were determined. Anthropogenic local sources seemed to be dominant during winter in both sites. However during spring biogenic influence increased. In addition to source analysis this behaviour was visible in enhanced diurnal cycles of VOCs (Patokoski et al., 2014, in press). We will present important sources and source areas for Southern Finland's concentrations. References: Patokoski, J., Ruuskanen, T.M., Hellén, H., Taipale, R., Grönholm, T., Kajos, M.K., Petäjä, T., Hakola, H., Kulmala, M. & Rinne, J., 2014. Winter to spring transition and diurnal variation of VOCs in Finland at an urban background site and a rural site. Boreal Env. Res. 19. In press.

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

2014-05-01

85

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS  

SciTech Connect

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

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

2003-07-01

86

Volatile organic compounds from garden waste  

Microsoft Academic Search

About 170 compounds were identified in the headspace or liquid exudate from garden waste. Typical for microbiological growth were branched and straight chain alcohols, carboxylic acids and esters C2–C8. Several of the substances have been identified in early studies of compost For some waste samples the organosulfur compound concentration (C1 and C3 mono-, di- and trisulfides) was ca. 10 mg\\/m3

Ken Wilkins; Kjeld Larsen

1996-01-01

87

Biorestoration of aquifers contaminated with organic compounds  

Microsoft Academic Search

Several forms of biological treatment can be used to treat contaminated aquifers. In situ treatment increases the activity of the indigenous organisms by the addition of nutrients and electron acceptor. Withdrawal and treatment technologies rely on removal of the ground water and any of several wastewater treatment processes to biodegrade the organics. Addition of acclimated or genetically engineered organisms may

M. D. Lee; J. M. Thomas; R. C. Borden; P. B. Bedient; C. H. Ward; J. T. Wilson; R. A. Conway

1988-01-01

88

Thermal diffusion desorption for the comprehensive analysis of organic compounds.  

PubMed

Comprehensive analysis of organic compounds is crucial yet challenging considering that information on elements, fragments, and molecules is unavailable simultaneously by current analytical techniques. Additionally, many compounds are insoluble or only dissolve in toxic solvents. A solvent- and matrix-free strategy has been developed which allows the organic compound analyzed in its original form. It utilizes thermal diffusion desorption with the solid analyte irradiated with high energy laser. It is capable of providing explicit elemental, fragmental, and molecular information simultaneously for a variety of organic compounds. Thermal diffusion desorption has many advantages compared to the electrospray and MALDI techniques. The protons that form the protonated molecular ions originate from the analyte itself. All the elements and fragments are also derived from the analyte itself, which provides abundant information and expedites the identification of organic compounds. PMID:24914465

Yin, Zhibin; Wang, Xiaohua; Li, Weifeng; He, Miaohong; Hang, Wei; Huang, Benli

2014-07-01

89

Oxidation of Organic Compounds in the Soil.  

E-print Network

.. ; .......................................... 27 lummary and Conclusions .................................... 27 [Blank Page in Original Bulletin] OXIDATION OF ORGANIC MATTER IN THE SOIL The osidation of organic matter in the soil is a matter of consider- le agricultural importance. Ammonia...~truction or loss from the soil may give rise to changes in physical character. The oxidation of organic matter containing nitrogen could be studied indirectly by means of the nitrates and ammonia produced. TT'e might assume that the oxidation of the carbon...

Fraps, G. S. (George Stronach)

1915-01-01

90

Organic Compounds in Circumstellar and Interstellar Environments  

NASA Astrophysics Data System (ADS)

Recent research has discovered that complex organic matter is prevalent throughout the Universe. In the Solar System, it is found in meteorites, comets, interplanetary dust particles, and planetary satellites. Spectroscopic signatures of organics with aromatic/aliphatic structures are also found in stellar ejecta, diffuse interstellar medium, and external galaxies. From space infrared spectroscopic observations, we have found that complex organics can be synthesized in the late stages of stellar evolution. Shortly after the nuclear synthesis of the element carbon, organic gas-phase molecules are formed in the stellar winds, which later condense into solid organic particles. This organic synthesis occurs over very short time scales of about a thousand years. In order to determine the chemical structures of these stellar organics, comparisons are made with particles produced in the laboratory. Using the technique of chemical vapor deposition, artificial organic particles have been created by injecting energy into gas-phase hydrocarbon molecules. These comparisons led us to believe that the stellar organics are best described as amorphous carbonaceous nanoparticles with mixed aromatic and aliphatic components. The chemical structures of the stellar organics show strong similarity to the insoluble organic matter found in meteorites. Isotopic analysis of meteorites and interplanetary dust collected in the upper atmospheres have revealed the presence of pre-solar grains similar to those formed in old stars. This provides a direct link between star dust and the Solar System and raises the possibility that the early Solar System was chemically enriched by stellar ejecta with the potential of influencing the origin of life on Earth.

Kwok, Sun

2015-02-01

91

COMPACT, CONTINUOUS MONITORING FOR VOLATILE ORGANIC COMPOUNDS - PHASE I  

EPA Science Inventory

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

92

LOSS OF ORGANIC CHEMICALS IN SOIL: PURE COMPOUND TREATABILITY STUDIES  

EPA Science Inventory

Comprehensive screening data on the treatability of 32 organic chemicals in soil were developed. Of the evaluated chemicals, 22 were phenolic compounds. Aerobic batch laboratory microcosm experiments were conducted using two soils: an acidic clay soil with ...

93

Micropatterned Polymeric Gratings as Chemoresponsive Volatile Organic Compound  

E-print Network

Micropatterned Polymeric Gratings as Chemoresponsive Volatile Organic Compound Sensors or physical means, including but not limited to covalent, ionic, van der Waals, or hydrogen- patterning of a "receptor" material, regardless of atomic or molecular structure, into a periodic array

94

IMPROVEMENT IN AIR TOXICS METHODS FOR VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

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

95

Synthesis of fluorinated organic compounds using oxygen difluoride  

NASA Technical Reports Server (NTRS)

Oxygen difluoride synthesis is a much simpler, higher-yield procedure than reactions originally followed to synthesize various fluorinated organic compounds. Extreme care is taken in working with oxygen difluoride as its reactions present severe explosion hazard.

Toy, M. S.

1971-01-01

96

METHODS FOR LEVEL 2 ANALYSIS BY ORGANIC COMPOUND CATEGORY  

EPA Science Inventory

The report gives Level 2 procedures, including results of a laboratory evaluation of detailed methods for analyzing organic chemicals in particular compound categories. The report, supplementing an earlier Level 2 procedures manual, provides an initial experimental data base as a...

97

ESTIMATION OF PHYSIOCHEMICAL PROPERTIES OF ORGANIC COMPOUNDS BY SPARC  

EPA Science Inventory

The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

98

40 CFR 60.392 - Standards for volatile organic compounds.  

Code of Federal Regulations, 2014 CFR

...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Automobile and Light Duty Truck Surface Coating Operations § 60.392 Standards for volatile organic compounds. On and...

2014-07-01

99

GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES  

EPA Science Inventory

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

100

SYNTHESIZING ORGANIC COMPOUNDS USING LIGHT-ACTIVATED TIO2  

EPA Science Inventory

High-value organic compounds have been synthesized successfully from linear and cyclic hydrocarbons, by photocatalytic oxidation using a semiconductor material, titanium dioxide (TiO2). Various hydrocarbons were partially oxgenated in both liquid and gaseous phase reactors usi...

101

BIODEGRADABILITY STUDIES WITH ORGANIC PRIORITY POLLUTANT COMPOUNDS  

EPA Science Inventory

Ninty-six organic priority pollutants (from EPA Effluent Guidelines Consent Decree) were studied to determine the extent and rate of microbial degradation and the acclimation periods needed for substrate biooxidation. The pollutants have been classified into groups with character...

102

Analysis of the volatile organic compounds in seized cocaine hydrochloride  

Microsoft Academic Search

The volatile organic compounds in seized cocaine hydrochloride were analyzed using Gas Chromatography Mass Spectrometry (GC\\/MS). Two different methods of sampling volatile compounds were investigated. In the first method, 20, 50, and 100 mg samples of seized cocaine hydrochloride were loaded into 2-inch glass tubes. The headspace of each tube was then purged with ultra high purity (UHP) helium and

Lindy E. Dejarme; Sara J. Lawhon; Prasenjit Ray; Michael R. Kuhlman

1997-01-01

103

Speciation of volatile organic compounds from poultry production  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

104

A New Method of Separation of Organic Compounds  

Microsoft Academic Search

DURING attempts to purify a yellow crystalline compound obtained from acetone extract of resin, Canarium strictum Roxb., which could not be purified either by recrystallization with various solvents and mixtures of solvents or by chromatography over alumina and calcium sulphate, a new method of separation of organic compounds by fractional crystallization on filter paper has been developed.

R. C. Vasisth; M. S. Muthana

1953-01-01

105

INDOOR AIR QUALITY DATA BASE FOR ORGANIC COMPOUNDS  

EPA Science Inventory

The report gives results of the compilation of a data base for concentrations of organic compounds measured indoors. ased on a review of the literature from 1979 through 1990, the data base contains information on over 220 compounds ranging in molecular weight from 30 to 446. he ...

106

Predicting the emission of volatile organic compounds from silage systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

107

DESTRUCTION OF VOLATILE ORGANIC COMPOUNDS VIA CATALYTIC INCINERATION  

EPA Science Inventory

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

108

Influence of surfactants on microbial degradation of organic compounds  

Microsoft Academic Search

Surfactants have the ability to increase aqueous concentrations of poorly soluble compounds and interfacial areas between immiscible fluids, thus potentially improving the accessibility of these substrates to microorganisms. However, both enhancements and inhibitions of biodegradation of organic compounds in the presence of surfactants have been reported. The mechanisms behind these phenomena are not well understood. To better understand the factors

Joseph D. Rouse; David A. Sabatini; Joseph M. Suflita; Jeffrey H. Harwell

1994-01-01

109

OCCURRENCE & CHEMISTRY OF ORGANIC COMPOUNDS IN HANFORD SITE WASTE TANKS  

Microsoft Academic Search

Volatile and semivolatile organic compounds continuously evolve from the waste tanks at the Hanford Site. Some are identical to the compounds originally transferred to tanks and others are formed through interdependent chemical and radiolytic reactions. This document provides a technical basis for understanding the chemical consequences of long term storage, sluicing, the addition of chemicals, and the prediction of other

L. M. STOCK; J. E. MEACHAM

2004-01-01

110

Shock Modifications of Organic Compounds in Carbonaceous Chondrite Parent Bodies  

NASA Technical Reports Server (NTRS)

Impacts among asteroidal objects would have altered or destroyed pre-existing organic matter in both targets and projectiles to a greater or lesser degree depending upon impact velocities. To begin filling a knowledge gap on the shock metamorphism of organic compounds, we are studying the effects of shock impacts on selected classes of organic compounds utilizing laboratory shock facilities. Our approach is to subject mixtures of organic compounds, embedded in the matrix of the Murchison meteorite, to simulated hypervelocity impacts by firing them into targets at various pressures. The mixtures are then analyzed to determine the amount of each compound that survives as well as to determine if new compounds are being synthesized. The initial compounds added to the matrix (with the exception of thiosulfate). The sulfonic acids were chosen in part because they are relatively abundant in Murchison, relatively stable, and because they and the phosphonic acids are the first well-characterized homologous series of organic sulfur and phosphorus compounds identified in an extraterrestrial material. Experimental procedures were more fully described in the original proposal. A 20 mm gun, with its barrel extending into a vacuum chamber (10(exp -2) torr), was used to launch the projectile containing the sample at approx. 1.6 km/sec (3,600 mi/hr) into the target material. Maximum pressure of impact depend on target/projectile materials. The target was sufficiently thin to assure minimum pressure decay over the total sample thickness.

Cooper, George W.

1998-01-01

111

Shock Modifications of Organic Compounds in Carbonaceous Chondrite Parent Bodies  

NASA Astrophysics Data System (ADS)

Impacts among asteroidal objects would have altered or destroyed pre-existing organic matter in both targets and projectiles to a greater or lesser degree depending upon impact velocities. To begin filling a knowledge gap on the shock metamorphism of organic compounds, we are studying the effects of shock impacts on selected classes of organic compounds utilizing laboratory shock facilities. Our approach is to subject mixtures of organic compounds, embedded in the matrix of the Murchison meteorite, to simulated hypervelocity impacts by firing them into targets at various pressures. The mixtures are then analyzed to determine the amount of each compound that survives as well as to determine if new compounds are being synthesized. The initial compounds added to the matrix (with the exception of thiosulfate). The sulfonic acids were chosen in part because they are relatively abundant in Murchison, relatively stable, and because they and the phosphonic acids are the first well-characterized homologous series of organic sulfur and phosphorus compounds identified in an extraterrestrial material. Experimental procedures were more fully described in the original proposal. A 20 mm gun, with its barrel extending into a vacuum chamber (10-2 torr), was used to launch the projectile containing the sample at approx. 1.6 km/sec (3,600 mi/hr) into the target material. Maximum pressure of impact depend on target/projectile materials. The target was sufficiently thin to assure minimum pressure decay over the total sample thickness.

Cooper, George W.

1998-06-01

112

Molecular and Enantiomeric Analysis of Organic Compounds in Carbonaceous Meteorites  

NASA Technical Reports Server (NTRS)

Carbonaceous meteorites are relatively enriched in carbon. Much of this carbon is in the form of soluble organic compounds. The Murchison and Murray meteorites are the best-characterized carbonaceous meteorites with respect to organic chemistry. Their content of organic compounds has led to an initial understanding of early solar system organic chemistry as well as what compounds may have played a role in the origin of life (Cronin and Chang, 1993). Reported compounds include: amino acids, amides, carboxylic acids, sulfonic acids, and polyols. This talk will focus on the molecular and enantiomeric analysis of individual meteoritic compounds: polyol acids; and a newly identified class of meteorite compounds, keto acids, i.e., acetoacetic acid, levulinic acid, etc. Keto acids (including pyruvic) are critically important in all contemporary organisms. They are key intermediates in metabolism and processes such as the citric acid cycle. Using gas chromatography-mass spectrometry we identified individual meteoritic keto acids after derivatization to one or more of the following forms: isopropyl ester (ISP), trimethyIsiIy1 (TMS), tert-butyldimethylsilyl (BDMS). Ongoing analyses will determine if, in addition to certain amino acids from Murchison (Cronin and Pizzarello, 1997), other potentially important prebiotic compounds also contain enantiomeric excesses, i.e., excesses that could have contributed to the current homochirality of life.

Cooper, George

2003-01-01

113

Process for reducing organic compounds with calcium, amine, and alcohol  

DOEpatents

Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about [minus]10 C to about 30 C or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

Benkeser, R.A.; Laugal, J.A.; Rappa, A.

1985-08-06

114

Process for reducing organic compounds with calcium, amine, and alcohol  

DOEpatents

Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about -10.degree. C. to about 30.degree. C. or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

Benkeser, Robert A. (West Lafayette, IN); Laugal, James A. (Lostant, IL); Rappa, Angela (Baltimore, MD)

1985-01-01

115

Composition and major sources of organic compounds in urban aerosols  

Microsoft Academic Search

Total suspended particles (TSP), collected during June 2002 to July 2003 in Guangzhou, a typical economically developed city in South China, were analyzed for the organic compound compositions using gas chromatography–mass spectrometry (GC\\/MS). Over 140 organic compounds were detected in the aerosols and grouped into different classes including n-alkanes, hopanoids, polycyclic aromatic hydrocarbons, alkanols, fatty acids, dicarboxylic acids excluding oxalic

Xinhui Bi; Bernd R. T. Simoneit; Guoying Sheng; Shexia Ma; Jiamo Fu

2008-01-01

116

Interlaboratory exercises for volatile organic compound determination  

NASA Astrophysics Data System (ADS)

The results of a European level intercomparison involving measurements of 26 hydrocarbons (from C2 to C9) at ambient air concentration level are discussed. On-line sampling with cryo-GC-FID analysis was the most commonly used methodology among the 20 participating laboratories. The stability of the gas samples in the canisters; the calibration methodology, the separation of peaks and the low level of concentrations were identified as the most important factors, which contributed to the increase in the uncertainty of the measurement. Uncertainty values associated with the common method used for the quantification of each compound and exercise were also determined.

Ballesta, P. Pérez; Field, R.; De Saeger, E.

117

Analysis of volatile organic compounds from illicit cocaine samples  

SciTech Connect

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

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

1994-07-01

118

COMPARISON OF AMBIENT AIR SAMPLING TECHNIQUES FOR VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

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

119

Students' Understanding of Molecular Structure and Properties of Organic Compounds.  

ERIC Educational Resources Information Center

The purpose of this study was to investigate senior high school students' difficulties predicting the existence of hydrogen bridge bonds between organic molecules, investigate students' difficulties predicting the relative boiling points of simple organic compounds, and develop test questions that enable teachers to quickly get information about…

Schmidt, Hans-Jurgen

120

Leveraging the beneficial compounds of organic and pasture milk  

Technology Transfer Automated Retrieval System (TEKTRAN)

Much discussion has arisen over the possible benefits of organic food, including milk. Organic milk comes from cows that are on pasture during the growing season, and would be expected to contain some compounds that are not found in animals receiving conventional feed, or at higher concentrations. ...

121

INTERACTIONS BETWEEN ORGANIC COMPOUNDS AND CYCLODEXTRIN-CLAY SYSTEMS  

EPA Science Inventory

Computational and experimental techniques are combined in order to better understand interactions involving organic compounds and cyclodextrin (CD)-clay systems. CD-clay systems may have great potential in the containment of organic contaminants in the environment. This study w...

122

BIOCONCENTRATION FACTORS FOR VOLATILE ORGANIC COMPOUNDS IN VEGETATION  

EPA Science Inventory

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

123

IDENTIFICATION OF ORGANIC COMPOUNDS IN INDUSTRIAL EFFLUENT DISCHARGES  

EPA Science Inventory

Samples of 63 effluent and 22 intake waters were collected from a wide range of chemical manufacturers in areas across the United States. The samples were analyzed for organic compounds in an effort to identify previously unknown and potentially hazardous organic pollutants. Each...

124

Highly stable meteoritic organic compounds as markers of asteroidal delivery  

NASA Astrophysics Data System (ADS)

Multiple missions to search for water-soluble organic compounds on the surfaces of Solar System bodies are either current or planned and, if such compounds were found, it would be desirable to determine their origin(s). Asteroid or comet material is likely to have been components of all surface environments throughout Solar System history. To simulate the survival of meteoritic compounds both during impacts with planetary surfaces and under subsequent (possibly) harsh ambient conditions, we subjected known meteoritic compounds to comparatively high impact-shock pressures (>30 GPa) and/or to extremely oxidizing/corrosive acid solution. Consistent with past impact experiments, ?-amino acids survived only at trace levels above ?18 GPa. Polyaromatic hydrocarbons (PAHs) survived at levels of 4-8% at a shock pressure of 36 GPa. Lower molecular weight sulfonic and phosphonic acids (S&P) had the highest degree of impact survival of all tested compounds at higher pressures. Oxidation of compounds was done with a 3:1 mixture of HCl:HNO3, a solution that generates additional strong oxidants such as Cl2 and NOCl. Upon oxidation, keto acids and ?-amino acids were the most labile compounds with proline as a significant exception. Some fraction of the other compounds, including non-? amino acids and dicarboxylic acids, were stable during 16-18 hours of oxidation. However, S&P quantitatively survived several months (at least) under the same conditions. Such results begin to build a profile of the more robust meteoritic compounds: those that may have survived, i.e., may be found in, the more hostile Solar System environments. In the search for organic compounds, one current mission, NASA's Mars Science Laboratory (MSL), will use analytical procedures similar to those of this study and those employed previously on Earth to identify many of the compounds described in this work. The current results may thus prove to be directly relevant to potential findings of MSL and other missions designed for extraterrestrial organic analysis.

Cooper, George; Horz, Friedrich; Spees, Alanna; Chang, Sherwood

2014-01-01

125

Can volatile organic compounds be markers of sea salt?  

PubMed

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. PMID:25236204

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

2015-02-15

126

Measurements of bromine containing organic compounds at the tropical tropopause  

Microsoft Academic Search

The amount of bromine entering the stratosphere from organic source gases is a primary factor involved in determining the magnitude of bromine catalyzed loss of ozone. Thirty two whole air samples were collected at the tropical tropopause during the NASA STRAT Campaign in Feb., Aug., and Dec., 1996 and were analyzed for brominated organic compounds. Total organic bromine was 17.4+\\/-0.9ppt

S. M. Schauffler; E. L. Atlas; F. Flocke; R. A. Lueb; V. Stroud; W. Travnicek

1998-01-01

127

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

Federal Register 2010, 2011, 2012, 2013, 2014

...applicability of Indiana's approved volatile organic compound (VOC) automobile...refinishing coatings or coating components that sell or distribute these...recordkeeping requirements, Volatile organic compounds. Dated:...

2010-01-14

128

Scaffold of Asymmetric Organic Compounds - Magnetite Plaquettes  

NASA Technical Reports Server (NTRS)

Life on Earth shows preference towards the set of organics with particular spatial configurations, this 'selectivity' is a crucial criterion for life. With only rare exceptions, life prefers the left- (L-) form over the right- (D-) form of amino acids, resulting in an L-enantiomeric excess (L-ee). Recent studies have shown Lee for alpha-methyl amino acids in some chondrites. Since these amino acids have limited terrestrial occurrence, the origin of their stereoselectivity is nonbiological, and it seems appropriate to conclude that chiral asymmetry, the molecular characteristic that is common to all terrestrial life form, has an abiotic origin. A possible abiotic mechanism that can produce chiral asymmetry in meteoritic amino acids is their formation with the presence of asymmetric catalysts, as mineral crystallization can produce spatially asymmetric structures. Magnetite is shown to be an effective catalyst for the formation of amino acids that are commonly found in chondrites. Magnetite 'plaquettes' (or 'platelets'), first described by Jedwab, show an interesting morphology of barrel-shaped stacks of magnetite disks with an apparent dislocation-induced spiral growth that seem to be connected at the center. A recent study by Singh et al. has shown that magnetites can self-assemble into helical superstructures. Such molecular asymmetry could be inherited by adsorbed organic molecules. In order to understand the distribution of 'spiral' magnetites in different meteorite classes, as well as to investigate their apparent spiral configurations and possible correlation to molecular asymmetry, we observed polished sections of carbonaceous chondrites (CC) using scanning electron microscope (SEM) imaging. The sections were also studied by electron backscattered diffraction (EBSD) in order to reconstruct the crystal orientation along the stack of magnetite disks.

Chan, Q. H. S.; Zolensky, M. E.; Martinez, J.

2015-01-01

129

GROUND WATER TRANSPORT OF HYDROPHOBIC ORGANIC COMPOUNDS IN THE PRESENCE OF DISSOLVED ORGANIC MATTER  

EPA Science Inventory

The effects of dissolved organic matter (DOM) on the transport of hydrophobic organic compounds in soil columns were investigated. hree compounds (naphthalene, phenathrene, and DDT) that spanned three orders of magnitude in water solubility were used. nstead of humic matter, mole...

130

GROUNDWATER TRANSPORT OF HYDROPHOBIC ORGANIC COMPOUNDS IN THE PRESENCE OF DISSOLVED ORGANIC MATTER  

EPA Science Inventory

The effects of dissolved organic matter (DOM) on the transport of hydrophobic organic compounds in soil columns were investigated. Three compounds (naphthalene, phenanthrene and DDT) that spanned three orders of magnitude in water solubility were used. Instead of humic matter, mo...

131

SDBS: Integrated Spectral Data Base System for Organic Compounds  

NSDL National Science Digital Library

Provided by Agency of Industrial Science and Technology of Japan, the Integrated Spectral Data Base System for Organic Compounds is a database of mass spectral, NMR (proton and carbon), and infrared spectra data. As of March 1999, the database contains 19,600 spectra of MS, 11,000 spectra of ^13 C NMR, 13,500 spectra of ^1 H NMR, 2,000 spectra of ESR, 47,500 spectra of IR, 3,500 spectra of Raman, and 30,000 compounds in the Compound Dictionary. A search engine (Frames) for the database allows the following fields to be specified: Compound Name, Molecular Formula, Number of Atoms (Carbon, Hydrogen, Oxygen, and Nitrogen), Molecular Weight, CAS Registry Number, and SDBS Number. Access is free; however, no more than 50 spectra and/or compound files may be downloaded in one day.

132

Dosimeter for monitoring vapors and aerosols of organic compounds  

DOEpatents

A dosimeter is provided for collecting and detecting vapors and aerosols of organic compounds. The dosimeter comprises a lightweight, passive device that can be conveniently worn by a person as a badge or placed at a stationary location. The dosimeter includes a sample collector comprising a porous web treated with a chemical for inducing molecular displacement and enhancing phosphorescence. Compounds are collected onto the web by molecular diffusion. The web also serves as the sample medium for detecting the compounds by a room temperature phosphorescence technique. 7 figs.

Vo-Dinh, T.

1987-07-14

133

Dosimeter for monitoring vapors and aerosols of organic compounds  

DOEpatents

A dosimeter is provided for collecting and detecting vapors and aerosols of organic compounds. The dosimeter comprises a lightweight, passive device that can be conveniently worn by a person as a badge or placed at a stationary location. The dosimeter includes a sample collector comprising a porous web treated with a chemical for inducing molecular displacement and enhancing phosphorescence. Compounds are collected onto the web by molecular diffusion. The web also serves as the sample medium for detecting the compounds by a room temperature phosphorescence technique.

Vo-Dinh, Tuan (625 Gulfwood Rd., Knoxville, TN 37923)

1987-01-01

134

Bioconcentration factors for volatile organic compounds in vegetation.  

PubMed

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

Hiatt, M H

1998-03-01

135

Analysis of the volatile organic compounds in seized cocaine hydrochloride  

NASA Astrophysics Data System (ADS)

The volatile organic compounds in seized cocaine hydrochloride were analyzed using Gas Chromatography Mass Spectrometry (GC/MS). Two different methods of sampling volatile compounds were investigated. In the first method, 20, 50, and 100 mg samples of seized cocaine hydrochloride were loaded into 2-inch glass tubes. The headspace of each tube was then purged with ultra high purity (UHP) helium and the gas exiting the tube was directed through a cryogenic loop filled with glass beads and maintained at liquid nitrogen temperature. The volatile organic compounds were collected onto the glass beads while the helium gas was vented. The organic compounds were subsequently thermally desorbed onto the column and analyzed by GC/MS. In the second method, 10 mg and 100 mg samples of seized cocaine hydrochloride were loaded into glass tubes fitted with glass frits at one end. UHP helium was purged through each sample and the purge gas containing organic compounds was collected onto a sorbent tube packed with Tenax TA. The concentrated organic compounds were then thermally desorbed onto a 4 m section of a split GC capillary column maintained at -70 degrees C with flow rates of 20-28 ml/min. Flow was returned to 2.8 ml/min during analysis. By sampling the seized samples of cocaine hydrochloride using a cryogenic loop, methanol, methyl ethyl ketone, acetic acid, 2,2,4-trimethyl pentane, 2-methyl pentane, dichloromethane, 2-propanol, and 2-propanol, and 2-propane (acetone) were found in three different seized cocaine hydrochloride samples. The observed quantities of these volatile organic compounds were different for each of the three seized cocaine hydrochloride samples. THe observed quantities of these volatile organic compounds were different for each of the three seized samples labeled A, B, and C. By sampling the seized samples of cocaine hydrochloride using sorbent tubes, cocaine was consistently observed. Although volatile components other than cocaine were observed, the number and amount of volatile components were not consistent with the cryogenic loop results.

Dejarme, Lindy E.; Lawhon, Sara J.; Ray, Prasenjit; Kuhlman, Michael R.

1997-02-01

136

Chemical reactions of organic compounds on clay surfaces.  

PubMed Central

Chemical reactions of organic compounds including pesticides at the interlayer and exterior surfaces of clay minerals and with soil organic matter are reviewed. Representative reactions under moderate conditions possibly occurring in natural soils are described. Attempts have been made to clarify the importance of the chemical nature of molecules, their structures and their functional groups, and the Brönsted or Lewis acidity of clay minerals. PMID:2533556

Soma, Y; Soma, M

1989-01-01

137

Non-targeted analyses of organic compounds in urban wastewater.  

PubMed

A large number of organic pollutants that cause damage to the ecosystem and threaten human health are transported to wastewater treatment plants (WWTPs). The problems regarding water pollution in Latin America have been well documented, and there is no evidence of substantive efforts to change the situation. In the present work, two methods to study wastewater samples are employed: non-targeted 1D ((13) C and (1) H) and 2D NMR spectroscopic analysis to characterize the largest possible number of compounds from urban wastewater and analysis by HPLC-(UV/MS)-SPE-ASS-NMR to detect non-specific recalcitrant organic compounds in treated wastewater without the use of common standards. The set of data is composed of several compounds with the concentration ranging considerably with treatment and seasonality. An anomalous discharge, the influence of stormwater on the wastewater composition and the presence of recalcitrant compounds (linear alkylbenzene sulfonate surfactant homologs) in the effluent were further identified. The seasonal variations and abnormality in the composition of organic compounds in sewage indicated that the procedure that was employed can be useful in the identification of the pollution source and to enhance the effectiveness of WWTPs in designing preventive action to protect the equipment and preserve the environment. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25354334

Alves Filho, Elenilson G; Sartori, Luci; Silva, Lorena M A; Silva, Bianca F; Fadini, Pedro S; Soong, Ronald; Simpson, Andre; Ferreira, Antonio G

2014-10-29

138

Key volatile organic compounds emitted from swine nursery house  

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

139

AERATION TO REMOVE VOLATILE ORGANIC COMPOUNDS FROM GROUND WATER  

EPA Science Inventory

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

140

ABSORPTION OF SOME ORGANIC COMPOUNDS THROUGH THE SKIN IN MAN  

Microsoft Academic Search

We studied the percutaneous penetration of 21 organic chemicals. The experimental method consisted of the application of the chemical to the human forearm and quantitating its penetration through the skin by its appearance in urine.There was a great diversity in the ability of the chemicals to penetrate human skin. Compounds such as hippuric acid, nicotinic acid, and nitrobenzene support the

Robert J. Feldmann; Howard I. Maibach

1970-01-01

141

Luminescent properties of organic compounds in nanodimensional aluminium oxide structures  

Microsoft Academic Search

Dielectric anodic oxide alumina films have a nanoscale 2D structure consisting of cylindrical pores placed perpendicularly to the surface. Such films with a regular structure where pores distance is equal to pore diameter and can be changed from 5 nm to 400 nm are created. The spectral and luminescent properties of different organic compounds luminescing in a wide spectral region

A. Kukhto; E. Kolesnik; A. Mozalev; M. Taoubi

1998-01-01

142

CHARACTERIZATION OF VOLATILE ORGANIC COMPOUND PROFILES OF BACTERIAL THREAT AGENTS  

Microsoft Academic Search

Volatile organic compound (VOC) profiles are potentially an underutilized class of threat agent signatures that may be exploited in the identification of threat agents. In the present study we first focused on determining if VOC profiles collected from liquid culture headspace could be utilized to differentiate between bacterium of different genus, in this case Bacillus and Yersinia. The second focus

Jennifer Horsmon; Kathy Crouse

143

The Survival of Meteorite Organic Compounds with Increasing Impact Pressure  

NASA Technical Reports Server (NTRS)

The majority of carbonaceous meteorites studied today are thought to originate in the asteroid belt. Impacts among asteroidal objects generate heat and pressure that may have altered or destroyed pre-existing organic matter in both targets and projectiles to a greater or lesser degree depending upon impact velocities. Very little is known about the shock related chemical evolution of organic matter relevant to this stage of the cosmic history of biogenic elements and compounds. The present work continues our study of the effects of shock impacts on selected classes of organic compounds utilizing laboratory shock facilities. Our approach was to subject mixtures of organic compounds, embedded in a matrix of the Murchison meteorite, to a simulated hypervelocity impact. The molecular compositions of products were then analyzed to determine the degree of survival of the original compounds. Insofar as results associated with velocities < 8 km/sec may be relevant to impacts on planetary surfaces (e.g., oblique impacts, impacts on small outer planet satellites) or grain-grain collisions in the interstellar medium, then our experiments will be applicable to these environments as well.

Cooper, George; Horz, Friedrich; Oleary, Alanna; Chang, Sherwood; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

144

Destruction of Volatile Organic Compounds Using Catalytic Oxidation  

Microsoft Academic Search

Catalytic oxidation is an air pollution control technique in which volatile organic compounds (VOCs) and vapor-phase air toxics in an air emission stream are oxidized with the help of a catalyst Design of catalytic systems for control of point source emissions is based on stream-specific characteristics and desired control efficiency. This paper discusses the key emission stream characteristics and VOC

Michael Kosusko; Carlos M. Nunez

1990-01-01

145

Effects of airborne volatile organic compounds on plants  

Microsoft Academic Search

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

J. N. Cape

2003-01-01

146

A titrimetric method for estimation of fluorine in organic compounds.  

PubMed

A simple and rapid titrimetric method for estimation of fluorine in organic compounds and fluoropolymers is reported. It involves combustion of the sample in oxygen, absorption of the combustion products in an aqueous solution of Ce(III) nitrate and glycerol, containing hexamethylenetetramine, and finally titration with EDTA, with Xylenol Orange and Methylene Blue as screened indicator. PMID:18964642

Das, P S; Adhikari, B; Maiti, M M; Maiti, S

1988-11-01

147

Organic compounds in the rain water of Los Angeles  

Microsoft Academic Search

Solvent-extractable and purgeable (volatile) organic matter was studied by using a capillary GC-MS in rain water from a station in West Los Angeles on the UCLA campus. More than 600 peaks were obtained on gas chromatograms, and approximately 300 compounds have so far been either identified or tentatively identified in the neutral, acidic, and basic fractions of solvent extracts, including

K. Kawamura; I. R. Kaplan

1983-01-01

148

Volatile organic compounds in Gulf of Mexico sediments  

Microsoft Academic Search

Volatile organic compounds (VOC), concentrations and compositions were documented for estuarine, coastal, shelf, slope, and deep water sediments from the Gulf of Mexico. VOC were measured (detection limit >0.01 ppb) using a closed-loop stripping apparatus with gas chromatography (GC) and flame ionization, flame photometric, and mass spectrometric detectors. The five primary sources of Gulf of Mexico sediment VOC are: (1)

1988-01-01

149

OXYGENATED ORGANIC COMPOUND CONCENTRATIONS NEAR A ROADWAY IN LITHUANIA, SSR  

EPA Science Inventory

During the period June 1 to June 9, 1989, aldehyde and other oxygenated organic compound concentrations were examined at sites 3, 10, and 80 meters northeast of the Vilnius-Kaunas highway in Lithuania, SSR by collecting 120 liter (1 L/min for 120 min) samples on 2,4-dinitrophenyl...

150

Modeling emissions of volatile organic compounds from silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

151

SORPTION OF IONIZABLE ORGANIC COMPOUNDS TO SEDIMENTS AND SOILS  

EPA Science Inventory

The sorption of ionizable organic compounds to sediments and saturated soils is examined. he sorption of pentachlorophenol to two sediment silt-clay fractions as a function of pH is described. Sorption of both the neutral and the ionic species was shown to occur; results were qua...

152

EMISSIONS OF REACTIVE VOLATILE ORGANIC COMPOUNDS FROM UTILITY BOILERS  

EPA Science Inventory

The report gives results of the measurement of emission factors for reactive volatile organic compounds (VOC) from 43 utility boilers firing bituminous coal, lignite, oil, and natural gas. The boilers ranged in size from 9 to 910 MW. The median reactive VOC emission factors were ...

153

Measuring Emissions of Volatile Organic Compounds from Silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

154

Volatile organic compound emissions from dairy facilities in central California  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

155

Chemo-enzymatic fluorination of unactivated organic compounds  

E-print Network

Chemo-enzymatic fluorination of unactivated organic compounds Andrea Rentmeister1, Frances H Arnold1 & Rudi Fasan1,2 Fluorination has gained an increasingly important role in drug discovery. This procedure was applied for the rapid identification of fluorinated drug derivatives with enhanced membrane

Arnold, Frances H.

156

Qualitative analysis of volatile organic compounds on biochar  

Microsoft Academic Search

Qualitative identification of sorbed volatile organic compounds (VOCs) on biochar was conducted by headspace thermal desorption coupled to capillary gas chromatographic-mass spectrometry. VOCs may have a mechanistic role influencing plant and microbial responses to biochar amendments, since VOCs can directly inhibit\\/stimulate microbial and plant processes. Over 70 biochars encompassing a variety of parent feedstocks and manufacturing processes were evaluated and

Kurt A. Spokas; Jeffrey M. Novak; Catherine E. Stewart; Keri B. Cantrell; Minori Uchimiya; Martin G. DuSaire; Kyoung S. Ro

2011-01-01

157

Destruction of volatile organic compounds via catalytic incineration  

Microsoft Academic Search

EPA's Air and Energy Engineering Research Laboratory conducts and sponsors research on technology to reduce or eliminate emissions of volatile organic compounds (VOC's) from industrial\\/commercial sources. Recently, a study on the use of catalytic oxidation to destroy VOC's (including potentially toxic air pollutants) was completed by Radian Corporation under an EPA contract. The study was designed to investigate the effect

B. A. Tichenor; M. A. Palazzolo

1985-01-01

158

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

EPA Science Inventory

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

159

FIELD-DEPLOYABLE MONITORS FOR VOLATILE ORGANIC COMPOUNDS IN AIR  

EPA Science Inventory

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

160

LEAVES AS INDICATORS OF EXPOSURE TO AIRBORNE VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

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

161

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

EPA Science Inventory

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

162

A global model of natural volatile organic compound emissions  

Microsoft Academic Search

Numerical assessments of global air quality and potential changes in atmospheric chemical constituents require estimates of the surface fluxes of a variety of trace gas species. We have developed a global model to estimate emissions of volatile organic compounds from natural sources (NVOC). Methane is not considered here and has been reviewed in detail elsewhere. The model has a highly

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

1995-01-01

163

MICROBIAL VOLATILE ORGANIC COMPOUND EMISSION RATES AND EXPOSURE MODEL  

EPA Science Inventory

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

164

Modeling emissions of volatile organic compounds from silage  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

165

PHOTOTHERMAL DESTRUCTION OF THE VAPOR OF ORGANIC COMPOUNDS  

EPA Science Inventory

The results of thermal and photothermal destruction of the vapors of organic compounds were compared by conducting tests in a photothermal detoxification unit. enon are lamp was used as the irradiation source. he tests were conducted on trichlorethylene (TCE), 1,2-dichlorobenzene...

166

Flammability of gas mixtures containing volatile organic compounds and hydrogen  

Microsoft Academic Search

An experimental program was conducted to evaluate the accuracy of some current methods for predicting the flammability of gas mixtures containing hydrogen and flammable or nonflammable volatile organic compounds (VOCs) in air. The specific VOCs tested were toluene, 1,2-dichloroethane, 2-butanone, and carbon tetrachloride. The lower flammability limits (LFLs) of gas mixtures containing equal molar quantities of the components were determined

Kevin J. Liekhus; Isaac A. Zlochower; Kenneth L. Cashdollar; Sinisa M. Djordjevic; Cindy A. Loehr

2000-01-01

167

PHOTOTHERMAL DESTRUCTION OF THE VAPOR OF VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

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

168

Qualitative analysis of volatile organic compounds on biochar  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

169

Structuring of bacterioplankton communities by specific dissolved organic carbon compounds.  

PubMed

The main role of microorganisms in the cycling of the bulk dissolved organic carbon pool in the ocean is well established. Nevertheless, it remains unclear if particular bacteria preferentially utilize specific carbon compounds and whether such compounds have the potential to shape bacterial community composition. Enrichment experiments in the Mediterranean Sea, Baltic Sea and the North Sea (Skagerrak) showed that different low-molecular-weight organic compounds, with a proven importance for the growth of marine bacteria (e.g. amino acids, glucose, dimethylsulphoniopropionate, acetate or pyruvate), in most cases differentially stimulated bacterial growth. Denaturing gradient gel electrophoresis 'fingerprints' and 16S rRNA gene sequencing revealed that some bacterial phylotypes that became abundant were highly specific to enrichment with specific carbon compounds (e.g. Acinetobacter sp. B1-A3 with acetate or Psychromonas sp. B3-U1 with glucose). In contrast, other phylotypes increased in relative abundance in response to enrichment with several, or all, of the investigated carbon compounds (e.g. Neptuniibacter sp. M2-A4 with acetate, pyruvate and dimethylsulphoniopropionate, and Thalassobacter sp. M3-A3 with pyruvate and amino acids). Furthermore, different carbon compounds triggered the development of unique combinations of dominant phylotypes in several of the experiments. These results suggest that bacteria differ substantially in their abilities to utilize specific carbon compounds, with some bacteria being specialists and others having a more generalist strategy. Thus, changes in the supply or composition of the dissolved organic carbon pool can act as selective forces structuring bacterioplankton communities. PMID:22697392

Gómez-Consarnau, Laura; Lindh, Markus V; Gasol, Josep M; Pinhassi, Jarone

2012-09-01

170

Characterization of polar organic compounds and source analysis of fine organic aerosols in Hong Kong  

Microsoft Academic Search

Organic aerosols, as an important fraction of airborne particulate mass, significantly affect the environment, climate, and human health. Compared with inorganic species, characterization of individual organic compounds is much less complete and comprehensive because they number in thousands or more and are diverse in chemical structures. The source contributions of organic aerosols are far from being well understood because they

Yunchun Li

2008-01-01

171

Analysis of organic compounds in returned comet nucleus samples  

NASA Technical Reports Server (NTRS)

Techniques for analysis of organic compounds in returned comet nucleus samples are described. Interstellar, chondritic and transitional organic components are discussed. Appropriate sampling procedures will be essential to the success of these analyses. It will be necessary to return samples that represent all the various regimes found in the nucleus, e.g., a complete core, volatile components (deep interior), and crustal components (surface minerals, rocks, processed organics such as macromolecular carbon and polymers). Furthermore, sampling, storage, return, and distribution of samples must be done under conditions that preclude contamination of the samples by terrestrial matter.

Cronin, J. R.

1989-01-01

172

Surface modification of inorganic layer compound with organic compound and preparation of thin films  

Microsoft Academic Search

Water treated ZnAl layered double hydroxide (LDH) was prepared by the reaction of LDH oxide and water. By the reaction of the water treated ZnAl LDH or amorphous metal hydroxide and organic oxychloride, surface modified inorganic layer compounds were prepared. Their layer structures were similar to those of the orginal LDHs except the reaction product of amorphous metal hydroxide and

Hideyuki Tagaya; Hiroyuki Morioka; Sumikazu Ogata; Masa Karasu; Jun-ichi Kadokawa; Koji Chiba

1997-01-01

173

Determination of fluorine in organic compounds: Microcombustion method  

USGS Publications Warehouse

A reliable and widely applicable means of determining fluorine in organic compounds has long been needed. Increased interest in this field of research in recent years has intensified the need. Fluorine in organic combinations may be determined by combustion at 900?? C. in a quartz tube with a platinum catalyst, followed by an acid-base titration of the combustion products. Certain necessary precautions and known limitations are discussed in some detail. Milligram samples suffice, and the accuracy of the method is about that usually associated with the other halogen determinations. Use of this method has facilitated the work upon organic fluorine compounds in this laboratory and it should prove to be equally valuable to others.

Clark, H.S.

1951-01-01

174

Measurements of halogenated organic compounds near the tropical tropopause  

NASA Technical Reports Server (NTRS)

The amount of organic chlorine and bromine entering the stratosphere have a direct influence on the magnitude of chlorine and bromine catalyzed ozone losses. Twelve organic chlorine species and five organic bromine species were measured from 12 samples collected near the tropopause between 23.8 deg N and 25.3 deg N during AASE 2. The average mixing ratios of total organic chlorine and total organic bromine were 3.50 +/- 0.06 ppbv and 21.1 +/- 0.8 pptv, respectively. CH3Cl represented 15.1% of the total organic chlorine, with CFC 11 (CCl3F) and CFC 12 (CCl2F2) accounting for 22.6% and 28.2%, respectively, with the remaining 34.1% primarily from CCl4, CH3CCl3, and CFC 113 (CCl2FCClF2). CH3Br represented 54% of the total organic bromine. The 95% confidence intervals of the mixing ratios of all but four of the individual compounds were within the range observed in low and mid-latitude mid-troposphere samples. The four compounds with significantly lower mixing ratios at the tropopause were CHCl3, CH2Cl2, CH2Br2, and CH3CCl3. The lower mixing ratios may be due to entrainment of southern hemisphere air during vertical transport in the tropical region and/or to exchange of air across the tropopause between the lower stratosphere and upper troposphere.

Schauffler, S. M.; Heidt, L. E.; Pollock, W. H.; Gilpin, T. M.; Vedder, J. F.; Solomon, S.; Lueb, R. A.; Atlas, E. L.

1993-01-01

175

Measurements of Halogenated Organic Compounds near the Tropical Tropopause  

NASA Technical Reports Server (NTRS)

The amount of organic chlorine and bromine entering the stratosphere have a direct influence on the magnitude of chlorine and bromine catalyzed ozone losses. Twelve organic chlorine species and five organic bromine species were measured from 12 samples collected near the tropopause between 23.8 deg N and 25.3 deg N during AASE 2. The average mixing ratios of total organic chlorine and total organic bromine were 3.50 +/- 0.06 ppbv and 21.1 +/- 0.8 pptv, respectively. CH3Cl represented 15.1% of the total organic chlorine, with CFC 11 (CCl3F) and CFC 12 (CCl2F2) accounting for 22.6% and 28.2%, respectively, with the remaining 34.1% primarily from CCl4, CH3CCl3, and CFC 113 (CCl2FCClF2). CH3Br represented 54% of the total organic bromine. The 95% confidence intervals of the mixing ratios of all but four of the individual compounds were within the range observed in low and mid-latitude midtroposphere samples. The four compounds with significantly lower mixing ratios at the tropopause were CHCl3, CH2Cl2, CH2Br2, and CH3CCl3. The lower mixing ratios may be due to entrainment of southern hemisphere air during vertical transport in the tropical region and/or to exchange of air across the tropopause between the lower stratosphere and upper troposphere.

Schauffler, S. M.; Heidt, L. E.; Pollock, W. H.; Gilpin, T. M.; Vedder, J. F.; Solomon, S.; Leub, R. A.; Atlas, E. L.

1993-01-01

176

Biodiversity of volatile organic compounds from five French ferns.  

PubMed

Five French ferns belonging to different families were investigated for volatile organic compounds (VOC) by GC-MS using organic solvent extraction. Fifty-five VOC biosynthesized from the shikimic, lipidic and terpenic pathways including monoterpenes, sesquiterpenes and carotenoid-type compounds were identified. The main volatile compound of Adiantum capillus-veneris L. (Pteridaceae) was (E)-2-decenal with a plastic or "stink bug" odor. The volatile profiles of Athyrium filix-femina (L.) Roth (Woodsiaceae) and Blechnum spicant (L.) Roth (Blechnaceae) showed similarities, with small amounts of isoprenoids and the same main volatile compounds, i.e., 2-phenylethanal (odor of lilac and hyacinth) and 1-octen-3-ol (mushroom-like odor). The main volatile compound of Dryopteris filix-mas (L.) Schott (Dryopteridaceae) was (E)-nerolidol with a woody or fresh bark note. Polyketides, as acylfilicinic acids, were mainly identified in this fern. Oreopteris limbosperma (Bellardi ex. All.) J. Holub (Thelypteridaceae), well-known for its lemon smell, contained the highest biodiversity of VOC. Eighty percent of the volatiles was issued from the terpenic pathway. The main volatiles were (E)-nerolidol, alpha-terpineol, beta-caryophyllene and other minor monoterpenes (for example, linalool, pinenes, limonene, and gamma-terpinen-7-al). It was also the fern with the highest number of carotenoid-type derivatives, which were identified in large amounts. Our results were of great interest underlying new industrial valorisation for ferns based on their broad spectrum of volatiles. PMID:21121267

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

2010-10-01

177

A Review of the Tissue Residue Approach for Organic and Organometallic Compounds in Aquatic Organisms  

EPA Science Inventory

This paper reviews the tissue residue approach (TRA) for toxicity assessment as it applies to organic chemicals and some organometallic compounds (tin, mercury, and lead). Specific emphasis was placed on evaluating key factors that influence interpretation of critical body resid...

178

DISTRIBUTION OF HYDROPHOBIC IONOGENIC ORGANIC COMPOUNDS BETWEEN OCTANOL AND WATER: ORGANIC ACIDS  

EPA Science Inventory

The octanol-water distributions of 10 environmentally significant organic acid compounds were determined as a function of aqueous-phase salt concentration (0.05-0.2 M LiCl, NaCl, KCl, CaCl2, or MgCl2) and pH. he compounds were pentachlorophenol 2,3,4,5-tetrachlorophenol, (2,4,5-t...

179

Group extraction of organic compounds present in liquid samples  

NASA Technical Reports Server (NTRS)

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.

Jahnsen, Vilhelm J. (Inventor)

1976-01-01

180

Natural organic compounds as tracers for biomass combustion in aerosols  

SciTech Connect

Biomass combustion is an important primary source of carbonaceous particles in the global atmosphere. Although various molecular markers have already been proposed for this process, additional specific organic tracers need to be characterized. The injection of natural product organic tracers to smoke occurs primarily by direct volatilization/steam stripping and by thermal alteration based on combustion temperature. The degree of alteration increases as the burn temperature rises and the moisture content of the fuel decreases. Although the molecular composition of organic matter in smoke particles is highly variable, the molecular structures of the tracers are generally source specific. The homologous compound series and biomarkers present in smoke particles are derived directly from plant wax, gum and resin by volatilization and secondarily from pyrolysis of biopolymers, wax, gum and resin. The complexity of the organic components of smoke aerosol is illustrated with examples from controlled burns of temperate and tropical biomass fuels. Burning of biomass from temperate regions (i.e., conifers) yields characteristic tracers from diterpenoids as well as phenolics and other oxygenated species, which are recognizable in urban airsheds. The major organic components of smoke particles from tropical biomass are straight-chain, aliphatic and oxygenated compounds and triterpenoids. The precursor-to-product approach of organic geochemistry can be applied successfully to provide tracers for studying smoke plume chemistry and dispersion.

Simoneit, B.R.T. [Brookhaven National Lab., Upton, NY (United States)]|[Oregon State Univ., Corvallis, OR (United States). Coll. of Oceanic and Atmospheric Sciences; Abas, M.R. bin [Brookhaven National Lab., Upton, NY (United States)]|[Univ. of Malaya, Kuala Lumpur (Malaysia); Cass, G.R. [Brookhaven National Lab., Upton, NY (United States)]|[California Inst. of Tech., Pasadena, CA (United States). Environmental Engineering Science Dept.; Rogge, W.F. [Brookhaven National Lab., Upton, NY (United States)]|[Florida International Univ., University Park, FL (United States). Dept. of Civil and Environmental Engineering; Mazurek, M.A. [Brookhaven National Lab., Upton, NY (United States); Standley, L.J. [Academy of Natural Sciences, Avondale, PA (United States). Stroud Water Research Center; Hildemann, L.M. [Stanford Univ., CA (United States). Dept. of Civil Engineering

1995-08-01

181

Metamaterial resonator arrays for organic and inorganic compound sensing  

NASA Astrophysics Data System (ADS)

In this paper, an electromagnetic metamaterial resonator operating in the terahertz frequency range is presented. By arranging the resonator in a planar array, it is possible to use the structure as a sensing device for organic and inorganic compounds. The sensor is designed to detect the presence of a biological compound by permittivity or absorption measurements. The presence of the biological matter modifies the effective permittivity and, thus, the resonant frequency significantly varies. In addition, biological compounds typically exhibit absorption characteristics that depend on the corresponding molecular structure. Therefore, it is necessary to illuminate the material selectively. We show that by employing the "selective" properties of the metamaterial resonator proposed, it is possible to enhance the sensing performances. The proposed design is suitable to sense the presence of healthy and malignant tissues, with possible applications in food and medical diagnostics. The operation of the sensing device has been demonstrated through proper full-wave simulations.

La Spada, Luigi; Bilotti, Filiberto; Vegni, Lucio

2011-09-01

182

Metamaterial resonator arrays for organic and inorganic compound sensing  

NASA Astrophysics Data System (ADS)

In this paper, an electromagnetic metamaterial resonator operating in the terahertz frequency range is presented. By arranging the resonator in a planar array, it is possible to use the structure as a sensing device for organic and inorganic compounds. The sensor is designed to detect the presence of a biological compound by permittivity or absorption measurements. The presence of the biological matter modifies the effective permittivity and, thus, the resonant frequency significantly varies. In addition, biological compounds typically exhibit absorption characteristics that depend on the corresponding molecular structure. Therefore, it is necessary to illuminate the material selectively. We show that by employing the "selective" properties of the metamaterial resonator proposed, it is possible to enhance the sensing performances. The proposed design is suitable to sense the presence of healthy and malignant tissues, with possible applications in food and medical diagnostics. The operation of the sensing device has been demonstrated through proper full-wave simulations.

La Spada, Luigi; Bilotti, Filiberto; Vegni, Lucio

2012-02-01

183

Bibliography on contaminants and solubility of organic compounds in oxygen  

NASA Technical Reports Server (NTRS)

A compilation of a number of document citations is presented which contains information on contaminants in oxygen. Topics covered include contaminants and solubility of organic compounds in oxygen, reaction characteristics of organic compounds with oxygen, and sampling and detection limits of impurities. Each citation in the data bank contains many items of information about the document. Some of the items are title, author, abstract, corporate source, description of figures pertinent to hazards or safety, key references, and descriptors (keywords) by which the document can be retrieved. Each citation includes an evaluation of the technical contents as to being good/excellent, acceptable, or poor. The descriptors used to define the contents of the documents and subsequently used in the computerized search operations were developed for the cryogenic fluid safety by experts in the cryogenics field.

Ordin, P. M. (compiler)

1975-01-01

184

Sugar-Related Organic Compounds in Carbonaceous Meteorites  

NASA Technical Reports Server (NTRS)

Sugars and related polyols are critical components of all organisms and may have been necessary for the origin of life. To date, this class of organic compounds had not been definitively identified in meteorites. This study was undertaken to determine if polyols were present in the early Solar System as constituents of carbonaceous meteorites. Results of analyses of the Murchison and Murray meteorites indicate that formaldehyde and sugar chemistry may be responsible for the presence of a variety of polyols. We conclude that polyols were present on the early Earth through delivery by asteroids and possibly comets.

Cooper, G.; Kimmich, N.; Belisle, W.; Sarinana, J.; Brabham, K.; Garrel, L.; DeVincenzi, Donald L. (Technical Monitor)

2001-01-01

185

Surfactant treatment to reduce vapors from volatile organic compounds  

SciTech Connect

Significant environmental health and fire hazards are associated with spills or leaks of solvents and fuels. Hazardous effects of vapor inhalation and the potential for fires in spill or leak situations are often overlooked as environmental hazards. Flammable and noxious organic vapors can be reduced significantly by treatment with a nonionic surfactant, FUELBUSTER{reg_sign}. Vapors above solvent solutions were sampled and analyzed by gas chromatography-flame ionization detection. Organic vapors were reduced 80--95% following treatment with a 6% aqueous solution of FUELBUSTER. Significant vapor reduction occurred within seconds of surfactant treatment. Experiments have been applied to a wide range of polar and nonpolar volatile compounds.

Cobb, G.P.; Stephens, M.D.; Waldrop, V.C. [Clemson Univ., Pendleton, SC (United States)

1995-12-31

186

Degradation of volatile organic compounds with thermally activated persulfate oxidation  

Microsoft Academic Search

This study investigated the extent and treatability of the degradation of 59 volatile organic compounds (VOCs) listed in the EPA SW-846 Method 8260B with thermally activated persulfate oxidation. Data on the degradation of the 59 VOCs (in mixture) reacted with sodium persulfate in concentrations of 1gl?1 and 5gl?1 and at temperatures of 20°C, 30°C, and 40°C were obtained. The results

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

2005-01-01

187

Water Pollution: Organic Compounds in the Charles River, Boston  

Microsoft Academic Search

The major lipophilic organic compounds present in water collected during November and December 1971 from the Charles River Basin (Boston) are as follows: normal alkanes (C15 to C31), alkyl naphthalenes, alkyl anthracenes or phenanthrenes, pyrene, fluoranthene, dibutyl phthalate, and di(2-ethylhexyl) phthalate. The concentration of the naphthalenes (determined by liquid chromatography) correlates with the effective storm-water runoff content of the river.

Ronald A. Hites; K. Biemann

1972-01-01

188

DEVELOPMENT OF OZONE REACTIVITY SCALES FOR VOLATILE ORGANIC COMPOUNDS  

Microsoft Academic Search

Methods for ranking photochemical ozone formation reactivities of volatile organic compounds(VOCs) are discussed. Photochemical mechanisms for the atmospheric reactions of 118 VOCs were usedto calculate their effects on ozone formation under various NO x conditions in model scenarios representing39 different urban areas. Their effects on ozone were used to derive 18 different ozone reactivity scales,one of which is the Maximum

William P. L. Carter

1994-01-01

189

Volatile organic compound emissions: an inventory for Western Europe  

SciTech Connect

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

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

1986-01-01

190

Trees and VOCs: Measuring volatile organic compounds from urban forests  

NSDL National Science Digital Library

This web site describes a research project to measure volatile organic compounds emitted from species of trees and shrubs found in urban areas. Topics include a description of the project and a section on trees and air quality. A page updated each month or so reports field and lab work on the project. There is also a glossary, profiles of community partners, and profiles of the scientists and students involved in the project.

Institute of Arctic and Alpine Research (INSTAAR) at the University of Colorado-Boulder

191

Seasonal characteristics of ambient volatile organic compounds in Seoul, Korea  

Microsoft Academic Search

The measurements of C2–C9 volatile organic compounds (VOC) were carried out at a site in Seoul, the capital of Korea from August 1998 to July 1999. Air samples were collected for 24h in 6l SUMMA canisters every 6 days. The canister samples were quantitatively analyzed by a GC\\/FID and GC\\/MS. The species with the highest mean concentration among the 70

Kwangsam Na; Yong Pyo Kim

2001-01-01

192

Simulation of Comet Impact and Survivability of Organic Compounds  

NASA Astrophysics Data System (ADS)

Comets have been proposed as a mechanism for the transport of complex organic compounds to Earth. For this to occur, a significant fraction of organic compounds must survive the shock loading, in particular the high temperatures, due to impact. 2D and 3D numerical simulations were performed to study the thermodynamic states due to a comet impact. The comet was modeled as a 1-km diameter icy sphere traveling at the Earth's escape velocity (11 km/s) impacting a half-space of basalt. Simulations were performed with GEODYN, a parallel, multi-material, Godunov-based Eulerian code employing adaptive mesh refinement. A constitutive model calibrated for hard rock was used for basalt. Tabular equations of state were used to account for the extreme conditions present upon shock loading. A major focus of the study was tracking the thermodynamic state of the comet material. Both the maximum temperature experienced and the phase were tracked for each point in the comet Temperature histories in the comet were also recorded. These quantities were used to estimate viability of organic compounds upon impact. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

Liu, Benjamin; Lomov, Ilya; Blank, Jennifer; Antoun, Tarabay

2007-06-01

193

Measurements of halogenated organic compounds near the tropical tropopause  

SciTech Connect

The amount of organic chlorine and bromine entering the stratosphere have a direct influence on the magnitude of chlorine and bromine catalyzed ozone losses. Twelve organic chlorine species and five organic bromine species were measured from 12 samples collected near the tropopause between 23.8[degrees]N and 25.3[degrees]N during AASE II. The average mixing ratios of total organic chlorine and total organic bromine were 3.50 [+-] 0.06 ppbv and 21.1 [+-] 0.8 pptv, respectively. CH[sub 3]Cl represented 15.1% of the total organic chlorine, with CFC 11 (CCl[sub 3]F) and CFC 12 (CCl[sub 2]F[sub 2]) accounting for 22.6% and 28.2%, respectively, with the remaining 34.1% primarily from CCl[sub 4], CH[sub 3]CCl[sub 3], and CFC 113 (CCl[sub 2]FCClF[sub 2]). CH[sub 3]Br represented 54% of the total organic bromine. The 95% confidence intervals of the mixing ratios of all but four of the individual compounds were within the range observed in low and mid-latitude mid-troposphere samples. The four compounds with significantly lower mixing ratios at the tropopause were CHCl[sub 3], CH[sub 2]Cl[sub 2], CH[sub 2]Br[sub 2], and CH[sub 3]CCl[sub 3]. The lower mixing ratios may be due to entrainment of southern hemisphere air during vertical transport in the tropical region and/or to exchange of air across the tropopause between the lower stratosphere and upper troposphere. 14 refs., 3 tabs.

Schauffler, S.M.; Heidt, L.E.; Pollock, W.H.; Gilpin, T.M.; Lueb, R.A.; Atlas, E.L. (National Center for Atmospheric Research, Boulder, CO (United States)); Vedder, J.F. (NASA Ames Research Center, Moffett Field, CA (United States)); Solomon, S. (NOAA Aeronomy Lab., Boulder, CO (United States))

1993-11-19

194

Simulation of Comet Impact and Survivability of Organic Compounds  

SciTech Connect

Comets have long been proposed as a potential means for the transport of complex organic compounds to early Earth. For this to be a viable mechanism, a significant fraction of organic compounds must survive the high temperatures due to impact. We have undertaken three-dimensional numerical simulations to track the thermodynamic state of a comet during oblique impacts. The comet was modeled as a 1-km water-ice sphere impacting a basalt plane at 11.2 km/s; impact angles of 15{sup o} (from horizontal), 30{sup o}, 45{sup o}, 65{sup o}, and 90{sup o} (normal impact) were examined. The survival of organic cometary material, modeled as water ice for simplicity, was calculated using three criteria: (1) peak temperatures, (2) the thermodynamic phase of H{sub 2}O, and (3) final temperature upon isentropic unloading. For impact angles greater than or equal to 30{sup o}, no organic material is expected to survive the impact. For the 15{sup o} impact, most of the material survives the initial impact and significant fractions (55%, 25%, and 44%, respectively) satisfy each survival criterion at 1 second. Heating due to deceleration, in addition to shock heating, plays a role in the heating of the cometary material for nonnormal impacts. This effect is more noticeable for more oblique impacts, resulting in significant deviations from estimates using scaling of normal impacts. The deceleration heating of the material at late times requires further modeling of breakup and mixing.

Liu, B T; Lomov, I N; Blank, J G; Antoun, T H

2007-07-18

195

Characterisation of polar organic compounds in fog water  

NASA Astrophysics Data System (ADS)

In this paper the results of a systematic liquid chromatographic investigation are described to characterise water-soluble organic compounds in fog. A diode array detector is used to record the UV spectrum of the components during separation and a mass spectrometer is applied to obtain information on the ion masses of the constituents. The combination of UV and mass spectra reveal that the organic carbon content of fog water is distributed among a great number of acidic compounds which have polar functional groups and polyconjugated systems absorbing up to 500 nm. Due to the complexity of the organic fraction in fog water an unresolved hump of ions was recorded by the mass spectrometer from m/ z=100-600 the most intense peaks being detected around m/ z=200-250. Tannin and fulvic acid were also examined under the same conditions. In terms of complexity and ion distribution the mass spectrum of the organic fraction was similar to that of a fulvic acid reference material rather than to that of tannin.

Kiss, Gyula; Varga, Bálint; Gelencsér, András; Krivácsy, Zoltán; Molnár, Ágnes; Alsberg, Tomas; Persson, Linn; Hansson, Hans-Christen; Cristina Facchini, Maria

196

Determination of organic nitro compounds using HPLC-UV-PAED  

NASA Astrophysics Data System (ADS)

High-performance liquid chromatography with ultra violet and photo-assisted electrochemical detection (HPLC-UV-PAED) has been applied to the sensitive and selective determination of organic nitro compounds. The system was first developed for the determination of nitro explosives, and PAED has shown superior sensitivity over UV detection for these compounds (i.e., <1 part-per-trillion for HMX). The system also shows enhanced selectivity over the traditional UV method in that two detectors can be used for improved analyte identification. Also, having two detectors permits chemometric resolution of overlapping peaks, and this is not addressed in the UV method. Because this method is applicable to a wide range of nitro explosives, it was predicted that PAED would show the same sensitivity and selectivity toward other types of nitro compounds. Since its development, the system's use has been expanded to include the determination of nitro-containing pharmaceuticals and glycosylated nitro compounds in biological matrices. Model compounds were chosen, specifically nitroglycerin and related compounds and nitrophenyl-glucoside, to represent these classes. PAED showed superior detection limits over low wavelength UV detection for nitroglycerin (PAED = 0.3ppb, UV at 220nm = 48ppb), demonstrating PAED"s applicability to determining nitro-pharmaceuticals. Conversely, UV detection at 220nm proved to be more sensitive than PAED for nitrophenyl-glucoside (UV at 220 = 0.6ppb, PAED = 3.6ppb). However, when nitrophenyl-glucoside was spiked into urine, PAED determination resulted in 99+0.3% recovery, while UV at 220nm resulted in 116+0.2% recovery, suggesting that UV determination may suffer from matrix interference.

Marple, Ronita L.; LaCourse, William R.

2004-12-01

197

Microbial cycling of volatile organic sulfur compounds in anoxic environments.  

PubMed

Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source. In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments. PMID:12188577

Lomans, B P; Pol, A; Op den Camp, H J M

2002-01-01

198

Loss of organic chemicals in soil: Pure compound treatability studies  

SciTech Connect

Comprehensive screening data on the treatability of 32 organic chemicals in soil were developed. Of the evaluated chemicals, 22 were phenolic compounds. Aerobic batch laboratory microcosm experiments were conducted using two soils: an acidic clay soil with <1 percent organic matter and a slightly basic sandy loam soil containing 3.25 percent organic matter. Loss rates were determined for the 32 chemicals with each soil and were higher in the basic soil. The loss rates were compared with chemical structure. Chlorophenols with chlorine substituted in the meta-position had greater half-lives and lower loss rates. Chemicals with a nitro group substituted in the phenol ring appeared to have a lower loss rate.

Loehr, R.C.; Matthews, J.E.

1992-01-01

199

Selective Sorption of Dissolved Organic Carbon Compounds by Temperate Soils  

SciTech Connect

Physico-chemical sorption of dissolved organic carbon (DOC) on soil minerals is one of the major processes of organic carbon (OC) stabilization in soils, especially in deeper layers. The attachment of C on soil solids is related to the reactivity of the soil minerals and the chemistry of the sorbate functional groups, but the sorption studies conducted without controlling microbial activity may overestimate the sorption potential of soil. This study was conducted to examine the sorptive characteristics of a diverse functional groups of simple OC compounds (D-glucose, L-alanine, oxalic acid, salicylic acid, and sinapyl alcohol) on temperate climate soil orders (Mollisols, Ultisols and Alfisols) with and without biological degradative processes. Equilibrium batch experiments were conducted using 0-100 mg C L-1 at a solid-solution ratio of 1:60 for 48 hrs and the sorption parameters were calculated by Langmuir model fitting. The amount of added compounds that remained in the solution phase was detected by high performance liquid chromatography (HPLC) and total organic C (TOC) analysis. Soil sterilization was performed by -irradiation technique and experiments were repeated to determine the contribution of microbial degradation to apparent sorption. Overall, Ultisols did not show a marked preference for apparent sorption of any of the model compounds, as indicated by a narrower range of maximum sorption capacity (Smax) of 173-527 mg kg soil-1 across compounds. Mollisols exhibited a strong preference for apparent sorption of oxalic acid (Smax of 5290 mg kg soil-1) and sinapyl alcohol (Smax of 2031 mg kg soil-1) over the other compounds. The propensity for sorption of oxalic acid is mainly attributed to the precipitation of insoluble Ca-oxalate due to the calcareous nature of most Mollisol subsoils and its preference for sinapyl alcohol could be linked to the polymerization of this lignin monomer on 2:2 mineral dominated soils. The reactivity of Alfisols to DOC was in between that of Ultisols and Mollisols. HPLC results revealed significantly higher sorption of D-glucose and L-alanine than did TOC results, and duplicate experiments with sterilized soils confirmed that glucose and alanine were mineralized leading to higher apparent sorption values via HPLC. This study demonstrated that three common temperate soil orders experienced differential sorption of simple OC compounds, indicating that sorbate chemistry plays a significant role in the sorptive stabilization of DOC.

Jagadamma, Sindhu [ORNL; Mayes, Melanie [ORNL; Phillips, Jana Randolph [ORNL

2012-01-01

200

Characterization of carbonaceous combustion residues: II. Nonpolar organic compounds.  

PubMed

Aromatic and aliphatic fractions of black carbon (BC) solvent extracts were examined by gas chromatography/mass spectrometry to determine how differences in broad chemical and physical features are correlated with the load, composition, "extractability" and bioavailability of organic compounds. Diesel soot, urban dust and chimney soot had concentrations of n-alkanes >20 microg/g and of carcinogenic polycyclic aromatic hydrocarbons (PAHs)>8 microg/g. These high levels of solvent-extractable compounds were interpreted as resulting from combustion at temperatures below optimum values for BC formation. PAH concentrations normalized to the amount of soot carbon in chimney soot were close to values for diesel soot. However, the high proportion of polar amorphous organic matter in chimney soot suggests a higher bioavailability for associated PAHs. Carbon black, vegetation fire residues, and straw and wood charcoals had only residual concentrations of n-alkanes (<9 microg/g) and PAHs (<0.2 microg/g). PAH distributions were mostly unspecific, while the overall signature of the aliphatic fraction varied with BC origin. Molecular markers among plant-derived BC included steroid and sesquiterpenoid hydrocarbons. Molecular fingerprints suggest that compounds associated with fossil BC might be more refractory than those associated with plant-derived BC. PMID:12948528

Fernandes, Milena B; Brooks, Peter

2003-11-01

201

Analyses of volatile organic compounds from human skin  

PubMed Central

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

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

2008-01-01

202

40 CFR Appendix Viii to Part 266 - Organic Compounds for Which Residues Must Be Analyzed  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Organic Compounds for Which Residues Must Be Analyzed VIII Appendix VIII to Part 266 Protection of Environment...to Part 266—Organic Compounds for Which Residues Must Be Analyzed Volatiles Semivolatiles Benzene...

2010-07-01

203

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-12-30

204

EVALUATION OF CRYOGENIC TRAPPING AS A MEANS FOR COLLECTING ORGANIC COMPOUNDS IN AMBIENT AIR  

EPA Science Inventory

The methodology used in reduced temperature preconcentration of volatile organic compounds has been tested using a prototype automated gas chromatographic system. Mixtures of sixteen volatile organic compounds in humidified zero air were passed through a Nafion tube dryer and the...

205

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Implementation Plans Alabama: Volatile Organic Compounds AGENCY: Environmental...definition of ``volatile organic compounds'' (VOCs) found...Planning Branch, Air, Pesticides and Toxics Management Division...Air Planning Branch, Air, Pesticides and Toxics Management...

2010-09-21

206

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

Code of Federal Regulations, 2014 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2014-07-01

207

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

Code of Federal Regulations, 2012 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2012-07-01

208

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

Code of Federal Regulations, 2013 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2013-07-01

209

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

Code of Federal Regulations, 2011 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2011-07-01

210

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

Code of Federal Regulations, 2010 CFR

...Volatile Organic Compound (VOC) emissions from bulk gasoline terminals. 60.502 ...Standards of Performance for Bulk Gasoline Terminals § 60.502 ...Organic Compound (VOC) emissions from bulk gasoline terminals. On and...

2010-07-01

211

The availability of dissolved organic phosphorus compounds to marine phytoplankton  

NASA Astrophysics Data System (ADS)

The availability of three dissolved organic phosphorus (DOP) compounds as nutrient sources for experimental culture of three algae was studied. Results indicated that these compounds could be utilized by algae, and that dissolved inorganic phosphorus (DIP) was first to be uptaken when various forms of phosphorus (DIP and DOP) co-existed. Dicrateria zhanjiangensis' uptake of sodium glycerophosphate was faster than that of D-ribose-5-phosphate. The increase of sodium glycerophosphate had little effect on the maximum uptake rate( V max) of Chlorella sp., but increased the semisaturation constant( K s) remarkably; the photosynthesis rates(PR) of Dicrateria zhanjiangensis and Chlorella sp. were rarely affected by using various forms of phosphorus in the culture experiments. The possible DOP pathways utilized by algae are discussed.

Hua-Sheng, Hong; Hai-Li, Wang; Bang-Qin, Huang

1995-06-01

212

Fate of Volatile Organic Compounds in Constructed Wastewater Treatment Wetlands  

USGS Publications Warehouse

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.

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

2004-01-01

213

Racemization and the origin of optically active organic compounds in living organisms  

NASA Technical Reports Server (NTRS)

The organic compounds synthesized in prebiotic experiments are racemic mixtures. A number of proposals have been offered to explain how asymmetric organic compounds formed on the Earth before life arose, with the influence of chiral weak nuclear interactions being the most frequent proposal. This and other proposed asymmetric syntheses give only sight enantiomeric excess and any slight excess will be degraded by racemization. This applies particularly to amino acids where half-lives of 10(5)-10(6) years are to be expected at temperatures characteristic of the Earth's surface. Since the generation of chiral molecules could not have been a significant process under geological conditions, the origins of this asymmetry must have occurred at the time of the origin of life or shortly thereafter. It is possible that the compounds in the first living organisms were prochiral rather than chiral; this is unlikely for amino acids, but it is possible for the monomers of RNA-like molecules.

Bada, J. L.; Miller, S. L.

1987-01-01

214

Photothermal destruction of the vapor of organic compounds  

SciTech Connect

The results of thermal and photothermal destruction of the vapors of organic compounds were compared by conducting tests in a photothermal detoxification unit. A xenon arc lamp was used as the irradiation source. The tests were conducted on trichloroethylene (TCE), 1,2-dichlorobenzene (DCB), and a mixture of benzene, toluene, ethyl benzene and m-xylene (BTEX). These materials represent various types of common pollutants at contaminated sites. The results showed that both TCE and DCB can be destroyed photothermally at much lower temperatures than in a pure thermal process. The photothermal effect of xenon arc radiation on BTEX was also clearly shown for all components except benzene; the effect was not as great as that on the chlorinated compounds. Carbon tetrachloride from TCE was the only significantly product of incomplete conversion observed in all experiments. The absorption spectra of these six compounds were taken at various temperatures using a custom-built high-temperature absorption spectrophotometer. The absorption strength, rate of photon absorption, and photothermal quantum yields of these six compounds all increased with temperature. The predicted radiant intensities of the mercury arc lamp and these predicted temperatures of the reactor for the complete mineralization of TCE, DCB and toluene were estimated using a mathematical model. The results showed that mercury arc lamp with relatively low radiant intensity is capable of destroying 99% of various categories of organic pollutants at moderate temperatures. This makes the process ideal for non-combustion on-site destruction of the off-gas from remediation technologies such as soil vapor extraction, thermal desorption and air stripping.

Chen, C.T. [Environmental Protection Agency, Edison, NJ (United States). Releases Control Branch] [Environmental Protection Agency, Edison, NJ (United States). Releases Control Branch; Graham, J.L.; Dellinger, B. [Univ. of Dayton Research Institute, OH (United States)] [Univ. of Dayton Research Institute, OH (United States)

1995-11-01

215

Seeking organic compounds on Mars : in situ analysis of organic compounds by Gas Chromatography-Mass Spectrometry on MOMA experiment  

NASA Astrophysics Data System (ADS)

The search for signs of past or present life is one of the primary goals of future Mars exploratory missions. The Mars Organic Molecule Analyzer (MOMA) experiment of the ExoMars mission (set to launch 2016-2018) is a joint venture by the European Space Agency and NASA to develop a sensitive detector for organics on Mars. MOMA will be one of the main analytical instruments aboard the ExoMars Rover aimed at characterizing possible “signs-of-life molecules” in the Martian environment such as amino acids, carboxylic acids, nucleobases or polycyclic aromatic hydrocarbons (PAHs). With the aim to separate and detect organic compounds from Martian soil, the French MOMA team has built a gas chromatograph able to work in standalone mode by using a TCD detector. The gas chromatograph can also be coupled with an ion trap mass spectrometer developed by the US MOMA team. Moreover, a GC-MS compatible sample processing system (SPS) allowing the extraction and the chemical transformation of the organic compounds from the soil, that fits within space flight conditions, has also been developed. The sample processing is performed in an oven, dedicated to the MOMA experiment containing the solid sample (50-100mg). The internal temperature of oven can be ranged from 20 to 1000 °C which allows for pyrolysis, thermochemolysis or derivatization. The organic extraction step is achieved by using thermodesorption in the range of 100 to 300°C for 0.5 to 5 min. Then, the chemical derivatization and/or thermochemolysis of the extracted compounds is performed directly on the soil with a mixture of MTBSTFA-DMF, TMAH or DMF-DMA solution when enantiomeric separation is required. By decreasing the polarity of the target molecules, this step allows for their volatilization at a temperature below 250°C without any chemical degradation. Once derivatized, the volatile target molecules are trapped in a cold chemical trap and promptly desorbed into the gas chromatograph coupled to the mass spectrometer. Preliminary tests, performed on several analogue soils such as Atacama soil, with the MOMA SPS-GC/MS experiment demonstrated the capability to detect organic compounds such as amino and carboxylic acids with sensitivities below the ppm level.

Buch, A.; Freissinet, C.; Sternberg, R.; Pinnick, V.; Szopa, C.; Coll, P. J.; Rodier, C.; Garnier, C.; Steininger, H.; Moma Team

2010-12-01

216

Volatile organic compounds in the unsaturated zone from radioactive wastes.  

PubMed

Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0-2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m yr. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere. PMID:22751077

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

2012-01-01

217

Volatile organic compounds in the unsaturated zone from radioactive wastes  

USGS Publications Warehouse

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.

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

2012-01-01

218

Process for removing an organic compound from water  

DOEpatents

A process for removing organic compounds from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. Apparatus for carrying out the process is also disclosed. The process is particularly suited for treatment of contaminated groundwater or industrial wastewater.

Baker, Richard W. (Palo Alto, CA); Kaschemekat, Jurgen (Palo Alto, CA); Wijmans, Johannes G. (Menlo Park, CA); Kamaruddin, Henky D. (San Francisco, CA)

1993-12-28

219

Organic compounds in produced waters from shale gas wells.  

PubMed

A detailed analysis is reported of the organic composition of produced water samples from typical shale gas wells in the Marcellus (PA), Eagle Ford (TX), and Barnett (NM) formations. The quality of shale gas produced (and frac flowback) waters is a current environmental concern and disposal problem for producers. Re-use of produced water for hydraulic fracturing is being encouraged; however, knowledge of the organic impurities is important in determining the method of treatment. The metal content was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Mineral elements are expected depending on the reservoir geology and salts used in hydraulic fracturing; however, significant levels of other transition metals and heavier main group elements are observed. The presence of scaling elements (Ca and Ba) is related to the pH of the water rather than total dissolved solids (TDS). Using gas chromatography mass spectrometry (GC/MS) analysis of the chloroform extracts of the produced water samples, a plethora of organic compounds were identified. In each water sample, the majority of organics are saturated (aliphatic), and only a small fraction comes under aromatic, resin, and asphaltene categories. Unlike coalbed methane produced water it appears that shale oil/gas produced water does not contain significant quantities of polyaromatic hydrocarbons reducing the potential health hazard. Marcellus and Barnett produced waters contain predominantly C6-C16 hydrocarbons, while the Eagle Ford produced water shows the highest concentration in the C17-C30 range. The structures of the saturated hydrocarbons identified generally follows the trend of linear > branched > cyclic. Heterocyclic compounds are identified with the largest fraction being fatty alcohols, esters, and ethers. However, the presence of various fatty acid phthalate esters in the Barnett and Marcellus produced waters can be related to their use in drilling fluids and breaker additives rather than their presence in connate fluids. Halogen containing compounds are found in each of the water samples, and although the fluorocarbon compounds identified are used as tracers, the presence of chlorocarbons and organobromides formed as a consequence of using chlorine containing oxidants (to remove bacteria from source water), suggests that industry should concentrate on non-chemical treatments of frac and produced waters. PMID:25162586

Maguire-Boyle, Samuel J; Barron, Andrew R

2014-10-01

220

Anthropogenic emissions of highly reactive volatile organic compounds in eastern Texas  

E-print Network

Anthropogenic emissions of highly reactive volatile organic compounds in eastern Texas inferred) columns provide top-down constraints on emissions of highly reactive volatile organic compounds (HRVOCs Anthropogenic highly reactive volatile organic compounds (AHRVOCs) with atmospheric lifetimes of less than a day

Mickley, Loretta J.

221

Source apportionment of airborne particulate matter using organic compounds as tracers  

Microsoft Academic Search

A chemical mass balance receptor model based on organic compounds has been developed that relates source contributions to airborne fine particle mass concentrations. Source contributions to the concentrations of specific organic compounds are revealed as well. The model is applied to four air quality monitoring sites in southern California using atmospheric organic compound concentration data and source test data collected

James J. Schauer; Wolfgang F. Rogge; Lynn M. Hildemann; Monica A. Mazurek; Glen R. Cass; Bernd R. T. Simoneit

2007-01-01

222

Source apportionment of airborne particulate matter using organic compounds as tracers  

Microsoft Academic Search

A chemical mass balance receptor model based on organic compounds has been developed that relates sours; contributions to airborne fine particle mass concentrations. Source contributions to the concentrations of specific organic compounds are revealed as well. The model is applied to four air quality monitoring sites in southern California using atmospheric organic compound concentration data and source test data collected

Bernd R. T. Simoneit; WOLFGANG F. ROGGE; LYNN M. HILDEMANN; MONICA A. MAZUREK; GLEN R. CASS

1996-01-01

223

Thermodynamics of Aqueous Organic Sulfur Compounds: A Key to the Organic Geochemistry of Hydrothermal Systems?  

NASA Technical Reports Server (NTRS)

Hydrothermal environments are locations of varied geochemistry due to the disequilibrium between vent fluids and seawater. The disequilibrium geochemistry has been hypothesized to include reactions to synthesize organic compounds. Observations of the organic geochemistry of hydrothermal vent sites has received little attention. Experimental simulations of these environments, however, indicate that organic compounds may have difficulty forming in a purely aqueous environment. On the other hand, thiols. thioesters and disulfides have been implicated as reaction intermediates between CO or CO2 in experiments of carbon reduction in hydrothermal environments as well as in a variety of biological processes and other abiotic reactions (Wachtershauser, 1990, OLEB 20, 173; Heinen and Lauwers, 1996, OLEB 26, 13 1, Huber and Wachtershauser, 1997, Science 276, 245; Russell et al., 1998, in Thermophiles: The keys to molecular evolution and the origin of life?). The reduction of CO2 to thiols, for example, is observed using the FeS-H2S/FeS2 couple to provide the reducing power (see Schoonen et al., 1999, OLEB 29, 5). In addition, the enzyme involved in final stage of methanogenesis, coenzyme-M, is itself a thiol. Thus, organic sulfur compounds may hold the key to the organic chemistry leading to the origin of life at high temperatures. Understanding the biochemical processes of microorganisms that can live to temperatures at least as high as 113 C (Blochl et al., 1996, Extremophiles 1, 14) requires knowledge of the properties of the chemical reactions involved. In order to assess the role of aqueous organic sulfur compounds in hydrothermal organic geochemistry, we have been attempting to determine their thermodynamic properties. We have culled the literature to obtain the properties of organic sulfur compounds. We are able to calculate a number of essential properties, such as free energies of formation, from solubility data available in the literature together with standard properties of organic sulfur gases. However, a number of the properties for aqueous organic sulfur compounds have not been experimentally determined. Furthermore, most of thermodynamic data that are available are for 25 C and 1 bar. In order to determine reaction properties to temperatures and pressures appropriate to the hydrothermal conditions in which thermophilic organisms actually live, we use equations of state developed by Helgeson and co-workers (Helgeson et al., 1981, AJS 281, 1249). A key piece of information needed to go up in temperature is the partial molal heat capacity, which is one of the properties for which experimental data are unavailable for nearly all organic sulfur compounds. We have used correlation methods to determine the partial molal heat capacities and volumes of many organic solutes. These estimates allow us to asses the role of organic sulfur compounds during the reduction of carbon in hydrothermal settings. We will present these data, along with examples of the thermodynamic properties of reactions involving aqueous organic sulfur compounds.

Schulte, Mitchell; Rogers, Karyn L.; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

224

ORGANIC CATION EFFECTS ON THE SORPTION OF METALS AND NEUTRAL ORGANIC COMPOUNDS ON AQUIFER MATERIAL (JOURNAL VERSION)  

EPA Science Inventory

Sorption of ethylhexadecyldimethylammonium (EHDDMA+), a large organic cation, and three neutral organic compounds (NOC's) on two low organic carbon aquifer materials was studied using a soil batch equilibration technique. EHDDMA+ competed effectively with metals for exchange site...

225

Cyclodextrin-based microsensors for volatile organic compounds  

SciTech Connect

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.

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

1997-10-01

226

Organochlorine Pesticide Compounds in Organisms from the Bay of Bengal  

NASA Astrophysics Data System (ADS)

Zooplankton and bottom-feeding fish (four species) from the coastal Bay of Bengal were analysed for residues of DDT, DDD, DDE and aldrin. Concentrations of t-DDT (DDT+DDD+DDE) ranging from 1·31 to 115·90 ng g -1 wet weight in different fish tissues and 4·00 to 1587·76 ng g -1 wet weight in zooplankton were found. Aldrin levels were of the order of 0·32-4·23 ng g -1 in the fish tissues and 'not detected' to 0·78 ng g -1 in zooplankton. The concentration levels are discussed in relation to the distribution of the compounds in different fish tissues, differences in the proportion of DDT and its metabolites DDE and DDD in the various organisms and the possible influence of suspended particulate matter on the availability of DDT residues to organisms in the water column.

Shailaja, M. S.; Singbal, S. Y. S.

1994-09-01

227

Laboratory Studies of Organic Compounds With Reflectance Spectroscopy  

NASA Astrophysics Data System (ADS)

In order to properly interpret reflectance spectra of any solar system surface from the earth to the Oort cloud, laboratory spectra of candidate materials for comparative analysis are needed. Although the common cosmochemical species (H2O, CO2, CO, NH3, and CH4) are well represented in the spectroscopic literature, comparatively little reflectance work has been done on organics from room to cryogenic temperatures at visible to near infrared wavelengths. Reflectance spectra not only enhance weak or unseen transmission features, they are also more analogous to spectra obtained by spacecraft that are imaging such bodies as giant planet moons, kuiper belt objects, centaurs, comets and asteroids, as well as remote sensing of the earth. The USGS Spectroscopy Laboratory is measuring reflectance spectra of organic compounds from room to cryogenic temperatures over the spectral range of 0.35 to 15.5 microns. This region encompasses the fundamental absorptions and many overtones and combinations of C, H, O, and N molecular bonds. Because most organic compounds belong to families whose members have similar structure and composition, individual species identification within a narrow wavelength range may be ambiguous. By measuring spectral reflectance of the pure laboratory samples from the visible through the near and mid-infrared, absorption bands unique to each can be observed, cataloged, and compared to planetary reflectance data. We present here spectra of organic compounds belonging to five families: the alkanes, alkenes, alkynes, aromatics, and cyanides. Common to all of these are the deep C-H stretch fundamental absorptions, which shift shortward from 3.35+ microns in alkanes to 3.25+ microns in aromatics, to 3.2+ microns in alkenes, and down to 3.0+ microns in alkynes. Mid-IR absorptions due to C-H bending deformations at 6.8+ and 7.2+ microns are also identified. In the near infrared these stretching and bending fundamentals yield a diagnostic set of combination absorptions at approximately 2.3 microns, as well as the first C-H stretching overtones at 1.6 to 1.7 microns, and even the second stretching overtones at 1.2+ microns. Additionally, the spectral properties of these organic materials have applications to remote sensing of terrestrial environments, including hazardous waste and disaster site characterization.

Curchin, J. M.; Clark, R. N.; Hoefen, T. M.

2007-12-01

228

Degradation of volatile organic compounds with thermally activated persulfate oxidation.  

PubMed

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

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

2005-10-01

229

Characterization of polar organic compounds and source analysis of fine organic aerosols in Hong Kong  

NASA Astrophysics Data System (ADS)

Organic aerosols, as an important fraction of airborne particulate mass, significantly affect the environment, climate, and human health. Compared with inorganic species, characterization of individual organic compounds is much less complete and comprehensive because they number in thousands or more and are diverse in chemical structures. The source contributions of organic aerosols are far from being well understood because they can be emitted from a variety of sources as well as formed from photochemical reactions of numerous precursors. This thesis work aims to improve the characterization of polar organic compounds and source apportionment analysis of fine organic carbon (OC) in Hong Kong, which consists of two parts: (1) An improved analytical method to determine monocarboxylic acids, dicarboxylic acids, ketocarboxylic acids, and dicarbonyls collected on filter substrates has been established. These oxygenated compounds were determined as their butyl ester or butyl acetal derivatives using gas chromatography-mass spectrometry. The new method made improvements over the original Kawamura method by eliminating the water extraction and evaporation steps. Aerosol materials were directly mixed with the BF 3/BuOH derivatization agent and the extracting solvent hexane. This modification improves recoveries for both the more volatile and the less water-soluble compounds. This improved method was applied to study the abundances and sources of these oxygenated compounds in PM2.5 aerosol samples collected in Hong Kong under different synoptic conditions during 2003-2005. These compounds account for on average 5.2% of OC (range: 1.4%-13.6%) on a carbon basis. Oxalic acid was the most abundant species. Six C2 and C3 oxygenated compounds, namely oxalic, malonic, glyoxylic, pyruvic acids, glyoxal, and methylglyoxal, dominated this suite of oxygenated compounds. More efforts are therefore suggested to focus on these small compounds in understanding the role of oxygenated compounds in aerosol chemistry and physics. By reference to tracers for the major organic aerosol sources, it is deduced that the oxygenated compounds are mainly of secondary origin and direct/indirect contribution from biomass burning could also be important. The chemical composition of these oxygenated species in PM2.5 samples in Hong Kong provide useful information to further ambient and model study in the aspects of chemical formation pathways and speciated organic mass distribution. (2) Source apportionment of PM2.5 organic aerosols in Hong Kong were carried out in two studies. In the first study, chemical characterization and source analysis involved samples collected on high particulate matter (PM) days (avg. PM 2.5 >84 mug m-3) at six general stations and one roadside station from October to December in 2003. Analysis of synoptic weather conditions identified three types of high PM episodes: local, regional transport (RT) and long-range transport (LRT). Roadside samples were discussed separately. Using chemical mass balance (CMB) model, contributions of major primary sources (vehicle exhaust, cooking, biomass burning, cigarette smoke, vegetative detritus, and coal combustion) were estimated, which indicate that vehicle exhaust was the most important primary source, followed by cooking and biomass burning. All primary sources except vegetative detritus had the highest contributions at roadside station, in line with its site characteristics. Primary sources dominated roadside and local samples (>64% of fine OC), while un-apportioned OC (i.e., the difference between measured OC and apportioned primary OC) dominated RT and LRT episodes (>60% of fine OC) and un-apportioned OC had characteristics of secondary OC. In the second study, cold front episodes during winter 2004 and 2005 were targeted to investigate the effect of cold front-related LRT on chemical characteristics and organic aerosol sources of PM2.5 in Hong Kong. In comparison with days under influences of mainly local emissions or RT, cold front LRT brought more organic aerosols attributable

Li, Yunchun

230

Biogenic volatile organic compound emissions from vegetation fires  

PubMed Central

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

CICCIOLI, PAOLO; CENTRITTO, MAURO; LORETO, FRANCESCO

2014-01-01

231

Fungal volatile organic compounds and their role in ecosystems.  

PubMed

All odorants are volatile organic compounds (VOCs), i.e., low molecular weight compounds that easily evaporate at normal temperatures and pressure. Fungal VOCs are relatively understudied compared to VOCs of bacterial, plant, or synthetic origin. Much of the research to date on fungal VOCs has focused on their food and flavor properties, their use as indirect indicators of fungal growth in agriculture, or their role as semiochemicals for insects. In addition, research into fungal volatiles has also taken place to monitor spoilage, for purposes of chemotaxonomy, for use in biofilters and for biodiesel, to detect plant and animal disease, for "mycofumigation," and with respect to plant health. As methods for the analysis of gas phase molecules have improved, it has become apparent that fungal VOC are more chemically varied and more biologically active than has generally been realized. In particular, there is increasing data that show that fungal VOCs frequently mediate interactions between organisms within and across different ecological niches. The goal of this mini review is to orchestrate data on fungal VOCs obtained from disparate disciplines as well as to draw attention to the ecological importance of fungal VOCs in signaling between different species. Technologies and approaches that are common in one area of research are often unknown in others, and the study of fungal VOCs would benefit from more cross talk between subdisciplines. PMID:25773975

Hung, Richard; Lee, Samantha; Bennett, Joan W

2015-04-01

232

Biogenic volatile organic compound emissions from vegetation fires.  

PubMed

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

Ciccioli, Paolo; Centritto, Mauro; Loreto, Francesco

2014-08-01

233

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

NASA Astrophysics Data System (ADS)

Organic aerosols are a highly-dynamic system dominated by both variable gas-particle partitioning and chemical evolution. Important classes of organics include semivolatile and intermediate volatility organic compounds (SVOC and IVOC, respectively). SVOCs are compounds that exist in both the gas and particle phases at typical atmospheric conditions while IVOC are low-volatility vapors that exist exclusively in the gas phase. Both classes have saturation concentrations that are orders of magnitude lower than volatile organic compounds (VOC) that are the traditional subjects of atmosphere chemistry, such as monoterpenes, alkyl benzenes, etc. The SVOC and IVOC are poorly represented for in current atmospheric chemistry models. Source testing indicates that SVOC and IVOC emissions from biomass combustion, diesel engines and other sources exceed the primary organic aerosol emissions; thus the oxidation of these vapors could serve as a significant source of organic aerosol in the atmosphere. The formation of secondary organic aerosol (SOA) from the reactions between OH radicals and SVOCs and IVOCs was investigated in the Carnegie Mellon University smog chamber. Experiments were conducted with n-alkanes and emission surrogates (diesel fuel and lubricating oil). SVOC oxidation produces oxidized organic aerosol but little new organic aerosol mass. This behavior can be explained by the coupled effects of partitioning and aging. Oxidation of SVOC vapors creates low volatility species that partition into the condensed phase; this oxidation also reduces the SVOC vapor concentration which, in turn, requires particle-phase SVOC to evaporate to maintain phase equilibrium. In contrast, oxidation of IVOC results in sustained production of SOA consistent with a reaction with relatively slow kinetics and high mass yield. Aerosol Mass Spectrometer data indicates that the SOA formed from IVOC has a mass spectrum that is quite similar to the oxygenated organic aerosol factor observed in field studies.

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

2008-12-01

234

Biogeochemical processes governing exposure and uptake of organic pollutant compounds in aquatic organisms.  

PubMed Central

This paper reviews current knowledge of biogeochemical cycles of pollutant organic chemicals in aquatic ecosystems with a focus on coastal ecosystems. There is a bias toward discussing chemical and geochemical aspects of biogeochemical cycles and an emphasis on hydrophobic organic compounds such as polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated organic compounds used as pesticides. The complexity of mixtures of pollutant organic compounds, their various modes of entering ecosystems, and their physical chemical forms are discussed. Important factors that influence bioavailability and disposition (e.g., organism-water partitioning, uptake via food, food web transfer) are reviewed. These factors include solubilities of chemicals; partitioning of chemicals between solid surfaces, colloids, and soluble phases; variables rates of sorption, desorption; and physiological status of organism. It appears that more emphasis on considering food as a source of uptake and bioaccumulation is important in benthic and epibenthic ecosystems when sediment-associated pollutants are a significant source of input to an aquatic ecosystem. Progress with mathematical models for exposure and uptake of contaminant chemicals is discussed briefly. PMID:1904812

Farrington, J W

1991-01-01

235

Organic colloid as a mode of transport for toxic halogenated organic compounds in the Mississippi river  

SciTech Connect

Suspended material was isolated from water samples from sixteen sites on the Mississippi River and its major tributaries from Minneapolis, Minn., to New Orleans, La., during the summer and fall of 1991 and the spring of 1992. The suspended material was separated into silt and colloid fractions in order to determine the proportion of associated toxic hydrophobic halogenated organic compounds transported on the colloid. The silt fraction (63 {mu}m to 1 {mu}m in diameter) was isolated first by centrifugation, then the colloidal fraction (1 {mu}m to 0.005 {mu}m in diameter) was isolated by tangential-flow ultrafiltration. The colloid averaged about 10 percent by weight of the total suspended material. Organic carbon content of the colloid ranged from 7 to 30 percent by weight. Silt organic carbon content ranged from 2 to 5 percent by weight. The proportion of suspended organic carbon transport in the river associated with the colloids averaged 35 percent of the total suspended organic carbon transport. Toxic halogenated organic compounds associated with both fractions included PCBs, chlordane, DCPA, hexachlorobenzene, and trifluralin. In some cases, transport of these compounds by the colloid fraction in the Mississippi River was greater than by the silt fraction.

Rostad, C.E. [Geological Survey, Arvada, CO (United States)

1995-12-01

236

Chiral Analyses of Organic Compounds in Carbonaceous Meteorites  

NASA Technical Reports Server (NTRS)

Contents include the following: 1. Characterization of Tagish Lake organic content. The first two grant years were largely devoted to the molecular and isotopic analyses of Tagish Lake organic composition. This carbonaceous meteorite fell in Canada in the winter of the year 2000, and its exceptional atmospheric entry and subsequent recovery (e. g., the sample was recovered and stored by avoiding hand contact and above freezing temperatures) contributed in providing a rare and pristine extraterrestrial material. 2. Chiral analyses of Murchison and Murray soluble organics. One of the most intriguing finding in regard to soluble meteorite organics is the presence within the amino acid suite of some compounds displaying L-enantiomeric excesses. This configuration is exclusive in the amino acids of terrestrial proteins and the finding has raised speculations of a possible role of amino acids from meteorites in the origin of homochirality on the early Earth. The main objective for this NASA funding was the characterization of enantiomeric excesses in meteorites and we have conducted several studies toward establishing their distribution and indignity.

Pizzarello, Sandra

2004-01-01

237

Determination of selenium and its compounds in marine organisms.  

PubMed

In this study, we investigate the type and quantity of selenium compounds in fish and marine organisms, using ion-pair reversed phase LC–ICP-MS, developed and applied for the analysis of Atlantic cod, Atlantic salmon, Greenland halibut, Atlantic herring, blue mussel, common crab, scallop, calanus, and Euphasia super. Of the samples examined, the lowest level of selenium was found in farmed Atlantic salmon (0.17 mg Se kg(?1) dm). The total selenium extraction efficiency by phosphate buffer was 2.5 times higher in sea plankton and shellfish samples than in fish samples. Analysis of Se species in each hydrolysate obtained by proteolysis showed the presence of selenomethionine, which constituted 41.5% of the selenium compounds detected in hydrolysates of Atlantic herring and 98.4% of those in extracts of Atlantic salmon. Inorganic compounds, such as selenates and selenites, were detected mainly in sea plankton and shellfish samples (<0.13 mg Se kg(?1) wm), although no correlation was found between the presence of inorganic compounds and total selenium concentration. The accuracy of the total selenium determination was validated using a certified reference material (oyster tissue (NIST 1566b)). A lyophilised powder of cod (Gadus morhua) was used to validate speciation analysis, enzymatic hydrolysis of lyophilised powder of cod recovered 54 ± 6% of total selenium, and SeMet constituted 83.5 ± 5.28% of selenium detected in hydrolysates. The chromatographic detection limits were, respectively, 0.30 ng mL(?1), 0.43 ng mL(?1), 0.54 ng mL(?1), 0.55 ng mL(?1), 0.57 ng mL(?1) and 0.72 ng mL(?1) for selenate, selenomethionine, selenite, Se-methyl-selenocysteine, selenocystine and selenomethionine selenoxide.The data on selenium concentrations and speciation presented here could be useful in estimating levels of selenium intake by seafood consumption. PMID:25468190

Bryszewska, Ma?gorzata Anita; Måge, Amund

2015-01-01

238

Nitrogen Containing Organic Compounds and Oligomers in Secondary Organic Aerosol Formed by Photooxidation of Isoprene  

SciTech Connect

Electrospray ionization high-resolution mass spectrometry (ESI HR-MS) was used to probe molecular structures of oligomers in secondary organic aerosol (SOA) generated in laboratory experiments on isoprene photooxidation at low- and high-NOx conditions. Up to 80-90% of the observed products are oligomers and up to 33% are nitrogen-containing organic compounds (NOC). We observe oligomers with up to 8 monomer units in length. Tandem mass spectrometry (MSn) confirms NOC compounds are organic nitrates and elucidates plausible chemical building blocks contributing to oligomer formation. Most organic nitrates are comprised of methylglyceric acid units. Other important multifunctional C2-C5 monomer units are identified including methylglyoxal, hydroxyacetone, hydroxyacetic acid, glycolaldehyde, and 2-methyltetrols. The majority of the NOC oligomers contain only one nitrate moiety resulting in a low average N:C ratio of 0.019. Average O:C ratios of the detected SOA compounds are 0.54 under the low-NOx conditions and 0.83 under the high-NOx conditions. Our results underscore the importance of isoprene photooxidation as a source of NOC in organic particulate matter.

Nguyen, Tran B.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Serguei

2011-07-06

239

Exposure to volatile organic compounds: Comparison among different transportation modes  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

240

Detection of volatile organic compounds using surface enhanced Raman scattering  

SciTech Connect

The authors present the detection of volatile organic compounds directly in their vapor phase by surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. The type of nanopillars is known as the tapered pillars. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of toluene vapor. The results show that SERS signal from a toluene vapor concentration of ppm level can be achieved, and the toluene vapor can be detected within minutes of exposing the SERS substrate to the vapor. A simple adsorption model is developed which gives results matching the experimental data. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors.

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

2012-03-22

241

Destruction of volatile organic compounds using catalytic oxidation  

SciTech Connect

Catalytic oxidation is an air pollution control technique in which volatile organic compounds (VOCs) and vapor-phase air toxics in an air emission stream are oxidized with the help of a catalyst. Design of catalytic systems for control of point source emissions is based on stream-specific characteristics and desired control efficiency. The paper discusses the key emission stream characteristics and VOC characteristics that affect the applicability of catalytic oxidation. The application of catalytic oxidation technology to four types of air emission sources is discussed: (1) groundwater stripping operations; (2) graphic arts facilities; (3) flexographic printing plants; and (4) latex monomer production. The characteristics of each of these emissions are discussed along with the catalytic technology used to control these emissions.

Kosusko, M.; Nunez, C.M.

1990-01-01

242

Destruction of volatile organic compounds using catalytic oxidation  

SciTech Connect

Catalytic oxidation is an air pollution control technique in which volatile organic compounds (VOCs) and vapor-phase air toxics in an air emission stream are oxidized with the help of a catalyst. Design of catalytic systems for control of point source emissions is based on stream-specific characteristics and desired control efficiency. This paper discusses the key emission stream characteristics and VOC characteristics that affect the applicability of catalytic oxidation. The application of catalytic oxidation technology to four types of air emission sources is discussed: (1) groundwater stripping operations; (2) graphic arts facilities; (3) flexographic printing plants; and (4) latex monomer production. The characteristics of each of these emissions are discussed along with the catalytic technology used to control these emissions.

Kosusko, M.; Nunez, C.M. (Environmental Protection Agency, Research Triangle Park, NC (USA))

1990-02-01

243

Volatile Organic Compound Optical Fiber Sensors: A Review  

PubMed Central

Volatile organic compound (VOC) detection is a topic of growing interest with applications in diverse fields, ranging from environmental uses to the food or chemical industries. Optical fiber VOC sensors offering new and interesting properties which overcame some of the inconveniences found on traditional gas sensors appeared over two decades ago. Thanks to its minimum invasive nature and the advantages that optical fiber offers such as light weight, passive nature, low attenuation and the possibility of multiplexing, among others, these sensors are a real alternative to electronic ones in electrically noisy environments where electronic sensors cannot operate correctly. In the present work, a classification of these devices has been made according to the sensing mechanism and taking also into account the sensing materials or the different methods of fabrication. In addition, some solutions already implemented for the detection of VOCs using optical fiber sensors will be described with detail.

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

2006-01-01

244

Source apportionment of volatile organic compounds in Tehran, Iran.  

PubMed

Identifying the sources of volatile organic compounds (VOCs) is key issue to reducing ground-level ozone and PAN. A multivariate receptor model (Unmix) was used for the determination of the contributions of VOCs sources in Tehran-Iran. Concentrations of ambient C2-C10 VOCs were measured continuously and online at the center of Tehran city during the winter of 2012. A high correlation coefficient existed between measured and predicted values (R (2) = 0.99), indicating that the data were well modeled. Five possible VOCs source categories were identified and mobile sources such as vehicle exhaust (61 %) and fuel evaporation (12 %) more than half of the total VOC concentration. City gas and CNG sources, biogenic source, and industrial solvent source categories accounted for 17 %, 8 % and 2 % of the total VOC, respectively. Result showed Unmix for VOCs source apportionment can be used to analyze and generate air pollution control strategies and policies. PMID:23283536

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

2013-04-01

245

Alveolar air volatile organic compound extractor for clinical breath sampling.  

PubMed

Alveolar air Volatile Organic Compound (VOC) extractor is a handheld breath-sampling device for clinical breath analysis. The device consists two main components: (1) An alveolar air separator, (2) A VOC extractor. The alveolar air separator splits exhaled air based on total exhaled air volume directing alveolar air towards the VOC extractor and dead space air to into an exhaust channel. The VOC extractor collects the VOCs from alveolar air into a modified Sold Phase Micro Extraction (SPME) filament. Feasibility of using the SPME filament to collect a quantifiable breath sample directly from exhaled breath is experimentally validated. Exhaled breath acetone is quantified using alveolar air VOC extractor and a GC/MS system. PMID:25571207

de Silva, Geethanga; Beyette, Fred R

2014-01-01

246

Flux Measurements of Volatile Organic Compounds from an Urban Landscape  

SciTech Connect

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

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

2005-10-19

247

Constituents of volatile organic compounds of evaporating essential oil  

NASA Astrophysics Data System (ADS)

Essential oils containing aromatic compounds can affect air quality when used indoors. Five typical and popular essential 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.

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

2009-12-01

248

Volatile organic compounds in foods: a five year study.  

PubMed

A purge and trap procedure was used with gas chromatography-mass spectrometry determination to analyze 70 foods for volatile organic compounds (VOCs). The results from analyses over a 5 year period (1996-2000) are reported. VOCs were found in at least one sample of all foods tested, although no single compound was found in each of the foods. The total amount of VOCs found in a single food item over the 5 year period ranged from 24 to 5328 ppb, with creamed corn (canned) the lowest and cheddar cheese the highest. Benzene was found in all foods except American cheese and vanilla ice cream. Benzene levels ranged from 1 to 190 ppb, with the highest level found in fully cooked ground beef. Benzene was found in 12 samples of cooked ground beef, with an average of 40 ppb. Benzene levels above 100 ppb were also seen in at least one sample each of a cola (138 ppb), raw bananas (132 ppb), and cole slaw (102 ppb). This compares to a maximum contaminant level of 5 ppb set by the U.S. EPA for drinking water. PMID:14690406

Fleming-Jones, Mary Ellen; Smith, Robert E

2003-12-31

249

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

PubMed

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. PMID:24471978

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

2014-10-01

250

A SURVEY ON RESEARCH NEEDS ON PERSONAL SAMPLERS FOR TOXIC ORGANIC COMPOUNDS  

EPA Science Inventory

A survey is presented on the research and development needs for personal monitoring devices for toxic organic compounds in the ambient atmosphere. This survey includes a description of organic compounds and their ambient concentrations, individual compounds of high priority, a su...

251

Mount St. Helens, Washington, 1980 volcanic eruption: characterization of organic compounds in ash samples  

Microsoft Academic Search

Volcanic ash samples obtained after the May 18, eruption of Mount St. Helens, Washington, were analyzed for organic compounds. Several n-alkanes, fatty acids, dicarboxylic acids, alcohols, phenols, aldehydes, aromatic acids, aromatic and polycyclic aromatic hydrocarbons and chlorinated aromatic compounds were identified by GC-MS. Pyrolysis of plants and soil organic matter is the most probable source of these compounds.

W. E. Pereira; C. E. Rostad; H. E. Taylor

1980-01-01

252

Exchange of volatile organic compounds in the boreal forest floor  

NASA Astrophysics Data System (ADS)

Terrestrial ecosystems, mainly plants, emit large amounts of volatile organic compounds (VOCs) into the atmosphere. In addition to plants, VOCs also have less-known sources, such as soil. VOCs are a very diverse group of reactive compounds, including terpenoids, alcohols, aldehydes and ketones. Due to their high reactivity, VOCs take part in formation and growth of secondary organic aerosols in the atmosphere and thus affect also Earth's radiation balance (Kulmala et al. 2004). We have studied boreal soil and forest floor VOC fluxes with chamber and snow gradient techniques we were developed. Spatial and temporal variability in VOC fluxes was studied with year-round measurements in the field and the sources of boreal soil VOCs in the laboratory with fungal isolates. Determination of the compounds was performed mass spectrometrically. Our results reveal that VOCs from soil are mainly emitted by living roots, above- and belowground litter and microbes. The strongest source appears to be litter, in which both plant residuals and decomposers play a role in the emissions. Soil fungi showed high emissions of lighter VOCs, like acetone, acetaldehyde and methanol, from isolates. Temperature and moisture are the most critical physical factors driving VOC fluxes. Since the environment in boreal forests undergoes strong seasonal changes, the VOC flux strength of the forest floor varies markedly during the year, being highest in spring and autumn. The high spatial heterogeneity of the forest floor was also clearly visible in VOC fluxes. The fluxes of other trace gases (CO2, CH4 and N2O) from soil, which are also related to the soil biological activity and physical conditions, did not show correlations with the VOC fluxes. These results indicate that emissions of VOCs from the boreal forest floor account for as much as several tens of percent, depending on the season, of the total forest ecosystem VOC emissions. This emphasises that forest floor compartment should be taken into consideration when assessing ecosystem level VOC fluxes. These results can be utilized also in air chemistry models, which are almost entirely lacking the below-canopy compartment. Kulmala, M., Suni, T., Lehtinen, K.E.J., Dal Maso, M., Boy, M., Reissell, A., Rannik, Ü., Aalto, P., Keronen, P., Hakola, H., Bäck, J., Hoffmann, T., Vesala, T. & Hari, P. 2004. A new feedback mechanism linking forests, aerosols, and climate. Atmospheric Chemistry and Physics 4: 557-562.

Aaltonen, Hermanni; 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

253

Identification of volatile organic compounds in human cerumen.  

PubMed

We report here the initial examination of volatile organic compounds (VOCs) emanating from human earwax (cerumen). Recent studies link a single nucleotide polymorphism (SNP) in the adenosine triphosphate (ATP) binding cassette, sub-family C, member 11 gene (ABCC11) to the production of different types of axillary odorants and cerumen. ABCC11 encodes an ATP-driven efflux pump protein that plays an important function in ceruminous apocrine glands of the auditory canal and the secretion of axillary odor precursors. The type of cerumen and underarm odor produced by East Asians differ markedly from that produced by non-Asians. In this initial report we find that both groups emit many of the same VOCs but differ significantly in the amounts produced. The principal odorants are volatile organic C2-to-C6 acids. The physical appearance of cerumen from the two groups also matches previously reported ethnic differences, viz., cerumen from East Asians appears dry and white while that from non-Asians is typically wet and yellowish-brown. PMID:24572763

Prokop-Prigge, Katharine A; Thaler, Erica; Wysocki, Charles J; Preti, George

2014-03-15

254

Supramolecular solvents in the extraction of organic compounds. A review.  

PubMed

The increasing pressure to decrease organic solvent usage in laboratories is fostering the search for alternative solvents. The liquid-liquid phase separation of surfactants, induced by environmental conditions, viz. temperature, electrolytes, pH, etc., has been largely used in analytical extraction and concentration schemes. The surfactant-rich phase is a nano-structured liquid, recently named as supramolecular solvent, generated from the amphiphiles through a sequential self-assembly process occurring on two scales, molecular and nano. This review covers progress on both theoretical and practical aspects related to the use of supramolecular solvents in analytical extractions reported over the last decade. Advances allowing a better understanding of the mechanisms of solvent production and solvent structure are outlined. Emphasis is then placed on solvent composition and its consequences on extraction efficiency, concentration factors and suitability for solubilising analytes over a wide range of polarities. Recent developments in formats and strategies making supramolecular solvents compatible with chromatographic and electrophoretic techniques along with a variety of detection systems are discussed. Applications of supramolecular solvents to the extraction of organic compounds mainly in the biological, environmental and agrifood areas are critically reviewed and main future trends outlined. PMID:20837178

Ballesteros-Gómez, Ana; Sicilia, María Dolores; Rubio, Soledad

2010-09-16

255

The seasonal variation in bioactive compounds content in juice from organic and non-organic tomatoes.  

PubMed

A specific objective of this paper was to evaluate seasonal changes in bioactive compounds level (carotenoids and polyphenols) in juice prepared from organic and non-organic tomatoes in Poland. In the examined tomato juice, the content of dry matter, vitamin C, carotenoids as well as polyphenols (by HPLC method) has been measured. The presented results indicate the impact of the growing system and the year of production on the composition of tomato juice. The organic tomato juice contained significantly more beta-carotene, chlorogenic acid, rutin as well as more total phenolic acids, gallic acid, p-coumaric acid, total flavonoids, quercetin-3-O-glucoside and quercetin in comparison with the non-organic. The tomato juice from 2008 contained significantly more carotenoids and some flavonoids compared to the one produced in 2009, which contained significantly more dry matter, vitamin C, as well as quercetin and it derivatives. PMID:23609833

Hallmann, Ewelina; Lipowski, Janusz; Marsza?ek, Krystian; Rembia?kowska, Ewa

2013-06-01

256

Normal Boiling Points for Organic Compounds: Correlation and Prediction by a Quantitative Structure-Property Relationship  

Microsoft Academic Search

We recently reported a successful correlation of the normal boiling points of 298 organic compounds containing O, N, Cl, and Br with two molecular descriptors.1 In the present study the applicability of these two descriptors for the prediction of boiling points for various other classes of organic compounds was investigated further by employing a diverse data set of 612 organic

Alan R. Katritzky; Victor S. Lobanov; Mati Karelson

1998-01-01

257

Selective Sorption of Dissolved Organic Carbon Compounds by Temperate Soils  

PubMed Central

Background Physico-chemical sorption onto soil minerals is one of the major processes of dissolved organic carbon (OC) stabilization in deeper soils. The interaction of DOC on soil solids is related to the reactivity of soil minerals, the chemistry of sorbate functional groups, and the stability of sorbate to microbial degradation. This study was conducted to examine the sorption of diverse OC compounds (D-glucose, L-alanine, oxalic acid, salicylic acid, and sinapyl alcohol) on temperate climate soil orders (Mollisols, Ultisols and Alfisols). Methodology Equilibrium batch experiments were conducted using 0–100 mg C L?1 at a solid-solution ratio of 1?60 for 48 hrs on natural soils and on soils sterilized by ?-irradiation. The maximum sorption capacity, Qmax and binding coefficient, k were calculated by fitting to the Langmuir model. Results Ultisols appeared to sorb more glucose, alanine, and salicylic acid than did Alfisols or Mollisols and the isotherms followed a non-linear pattern (higher k). Sterile experiments revealed that glucose and alanine were both readily degraded and/or incorporated into microbial biomass because the observed Qmax under sterile conditions decreased by 22–46% for glucose and 17–77% for alanine as compared to non-sterile conditions. Mollisols, in contrast, more readily reacted with oxalic acid (Qmax of 886 mg kg?1) and sinapyl alcohol (Qmax of 2031 mg kg?1), and no degradation was observed. The reactivity of Alfisols to DOC was intermediate to that of Ultisols and Mollisols, and degradation followed similar patterns as for Ultisols. Conclusion This study demonstrated that three common temperate soil orders experienced differential sorption and degradation of simple OC compounds, indicating that sorbate chemistry plays a significant role in the sorptive stabilization of DOC. PMID:23209742

Jagadamma, Sindhu; Mayes, Melanie A.; Phillips, Jana R.

2012-01-01

258

Delivery of complex organic compounds from evolved stars to the solar system.  

PubMed

Stars in the late stages of evolution are able to synthesize complex organic compounds with aromatic and aliphatic structures over very short time scales. These compounds are ejected into the interstellar medium and distributed throughout the Galaxy. The structures of these compounds are similar to the insoluble organic matter found in meteorites. In this paper, we discuss to what extent stellar organics has enriched the primordial Solar System and possibly the early Earth. PMID:22139515

Kwok, Sun

2011-12-01

259

IDENTIFICATION AND QUANTIFICATION OF AEROSOL POLAR OXYGENATED COMPOUNDS BEARING CARBOXYLIC OR HYDROXYL GROUPS. 2. ORGANIC TRACER COMPOUNDS FROM MONOTERPENES  

EPA Science Inventory

A comparison was made of polar organic compounds found in the field with those produced in secondary organic aerosol from laboratory irradiations of natural hydrocarbons and oxides of nitrogen. The field samples comprised atmospheric particulate matter (PM2.5) collect...

260

TREATMENT OF VOLATILE ORGANIC COMPOUNDS IN DRINKING WATER  

EPA Science Inventory

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

261

Volatile Organic Compounds in the Global Atmosphere (Invited)  

NASA Astrophysics Data System (ADS)

The World Meteorological Organization (WMO) - Global Atmospheric Watch (GAW) has been guiding the implementation of a global program for the monitoring of atmospheric volatile organic compounds (VOC). Essential features are 1. regular, in-situ, high temporal resolution measurements of VOC at surface stations, 2. VOC analyses in samples collected within flask sampling networks for wide geographical coverage, and 3. a concerted calibration and data quality control effort. A centerpiece of the flask sampling component builds upon the US NOAA Earth System Research Laboratory - Global Cooperative Air Sampling Network. Nine non-methane hydrocarbon species (NMHC; ethane, propane, iso-butane, n-butane, iso-pentane, n-pentane, isoprene, benzene, toluene) are currently analyzed by an automated gas chromatography system at the University of Colorado’s Institute of Arctic and Alpine Research (INSTAAR) in pairs of samples collected bi-weekly at 41 global background monitoring sites. Since the implementation of this program in 2004 more than 7000 measurements have been obtained. The obtained data allow elucidating the geographical and seasonal behavior of atmospheric NMHC, as well as interannual variations. Results show a wide dynamic range of mixing ratio changes. Concentration maxima and seasonal cycles are most pronounced in regions of highest emission sources and highest changes in the seasonal OH radical sink, i.e. the northern high and mid-latitudes. Seasonal southern hemisphere (SH) maxima are ~7 times and ~20 times lower for ethane and propane than in the northern hemisphere, which mainly reflects the smaller source strength of these gases in the SH. The richness of information in these data will help constraining the variability in global atmospheric oxidation chemistry and regional budgets of greenhouse gases, such as of methane and CO2, and most certainly stimulate further interests and applications in many fields of atmospheric chemistry and climate research. Global distribution of ethane during 2004-2010 as derived from in ~7000 flask samples collected at 41 remote sites of the NOAA-ESRL network.

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

2010-12-01

262

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries  

DOEpatents

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

Doherty, J.P.; Marek, J.C.

1987-02-25

263

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries  

DOEpatents

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper (II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the orginal organic compounds, is subsequently blended with high level radioactive sludge and transferred to a virtrification facility for processing into borosilicate glass for long-term storage.

Doherty, Joseph P. (Elkton, MD); Marek, James C. (Augusta, GA)

1989-01-01

264

Evaluation of Volatile Organic Compound Emissions from Megacities and Wildfires  

NASA Astrophysics Data System (ADS)

Volatile organic compounds (VOCs) play a critical role in determining air quality through their impact on ozone production and other pollutants. Tropospheric chemistry models use a variety of treatments for the lumping of VOCs in their chemical mechanisms, as a compromise between detailed treatment and computational speed. However, emission inventories are frequently provided for only total VOCs with little or no information on how to split the emissions among the model species, introducing additional uncertainty to the model simulations. Global model simulations using the Model for Ozone and Related Chemical Tracers (MOZART-4) and several different emission inventories are evaluated through detailed comparison to aircraft and surface observations. In particular, correlations between measured VOCs and CO are used to test the emission inventory emission ratios of the modeled VOC species. For example, megacity VOC emissions will be evaluated with surface measurements in Mumbai, Shanghai and Tokyo, as well as aircraft measurements from the NSF/MIRAGE experiment downwind of Mexico City. Wildfire emissions in Siberia, Canada and California will be evaluated using airborne observations of the NASA/ARCTAS experiment.

Emmons, L. K.; Apel, E. C.; Hornbrook, R. S.; Riemer, D. D.; Lamarque, J.; Wiedinmyer, C.; Mirage Science Team; Arctas Science Team

2011-12-01

265

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

PubMed

Centenarians are a model to study human longevity and the physiological process of aging. A plethora of studies on this model show the complexity of the system. Laboratory studies fail to find a biomarker of senescence. The real time exhaled breath volatile organic compounds (VOCs) has been suggested as a new biomarker to detect and monitor physiological processes in the respiratory system. VOCs exhaled by centenarians have not been studied in the general population and across-age-groups. In the present study we investigated, in real time, the breath properties and VOC exhaled content in healthy centenarians as compared with non-centenarian seniors and young healthy subjects. We found distinctly different breath pattern and distribution profiles of VOCs in the centenarians. Thus, the VOCs measurement allowed to discriminate the differences between the age-groups. We propose a VOCs fingerprint as a biomarker underlying the physiological mechanisms of aging and longevity. Longevity should be considered physiologically as a new phase of life, characteristic of the well adapted subject. PMID:25542135

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

2015-04-01

266

Identification of nonmethane organic compound emissions from grassland vegetation  

NASA Astrophysics Data System (ADS)

Emissions of nonmethane organic compounds (NMOCs) from grassland vegetation were collected in Summa ® passivated stainless-steel canisters with a static enclosure technique and were analyzed by high-resolution gas chromatography with flame ionization and ion trap mass spectrometric detectors. Approximately 40 NMOCs with 6-10 carbon atoms were observed in samples analyzed by high-resolution gas chromatography with the flame ionization detector. Nineteen NMOCs in this molecular weight range (6 aliphatic oxygenates; 1 aromatic hydrocarbon; and 4 acyclic, 5 monocyclic, and 3 bicyclic monoterpenoids) were identified by ion trap mass spectrometry. Mass spectrometry was particularly useful for identifying myrcene and cis-3-hexenylacetate, which coeluted on a fused-silica capillary column coated with a 1-?m-thick film of polydimethylsiloxane. An evaluation of the reactivity of the grassland emissions revealed that the aliphatic oxygenates have lifetimes of a few hours with respect to oxidation by OH and O 3 in the atmosphere. This value is similar to the lifetimes of the bicyclic monoterpenoids. The expected lifetimes of the monoterpenoids with respect to oxidation by NO 3 are only several minutes.

Fukui, Yoshiko; Doskey, Paul V.

267

Advanced heat pump for the recovery of volatile organic compounds  

NASA Astrophysics Data System (ADS)

Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total U.S. VOC emissions. The 'Toxic-Release Inventory' of the U.S. Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing, refrigerant production, and wood products production. The U.S. Department of Energy's (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase 1 report documents 3M's work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. The Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient, and economically priced.

1992-03-01

268

Predicting the emission rate of volatile organic compounds fromvinyl flooring  

SciTech Connect

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

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

2001-03-01

269

Cost effective passive sampling device for volatile organic compounds monitoring  

NASA Astrophysics Data System (ADS)

A laboratory-built passive sampler was developed as a simple and cost effective device for monitoring volatile organic compounds (VOCs) such as benzene, toluene and xylene (BTX). Common glass bottles (screw cap, 10 ml, 67.6×10.6 mm ID), packed with 75 mg of activated Tenax TA, were used as passive samplers. After exposed to real sample, the adsorbent was desorbed using a laboratory-built thermal desorption device. The analytes were purged to fill a sampling loop and then injected by a gas sampling valve to a gas chromatograph with a flame ionization detector (FID). All parameters, i.e. , desorption time, purge flow rate, gas chromatograph conditions were optimized to obtain high sensitivity, resolution and short analysis time. The system was calibrated by BTX standard gas and the linear regression coefficient of greater than 0.99 was obtained with detection limits 0.3, 0.2 and 0.7 ?g m -3 for benzene, toluene and xylene, respectively. The proposed method was implemented for the monitoring of BTX at 10 gasoline stations in Hat Yai, Thailand. The concentrations were found in the range of N.D.-19, 12-200 and 23-200 ?g m -3 for benzene, toluene and xylene, respectively.

Thammakhet, Chongdee; Muneesawang, Vilailuk; Thavarungkul, Panote; Kanatharana, Proespichaya

270

Advanced heat pump for the recovery of volatile organic compounds  

SciTech Connect

Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total US VOC emissions. The Toxic-Release Inventory'' of The US Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing,refrigerant production, and wood products production. The US Department of Energy's (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase I report documents 3M's work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient and economically priced.

Not Available

1992-03-01

271

Volatile organic compound monitoring by photo acoustic radiometry  

SciTech Connect

Two methods for sampling and analyzing volatile organics in subsurface pore gas were developed for use at the Hazardous Waste Disposal Site at Los Alamos National Laboratory. One is Thermal Desorption Gas Chromatography Mass Spectrometry (TDGCMS), the other is Photoacoustic Radiometry (PAR). Presented here are two years worth of experience and lessons learned as both techniques matured. The sampling technique is equally as important as the analysis method. PAR is a nondispersive infrared technique utilizing band pass filters in the region from 1 to 15 {mu}m. A commercial instrument, the Model 1302 Multigas Analyzer, made by Bruel and Kjaer, was adapted for field use. To use the PAR there must be some a priori knowledge of the constellation of analytes to be measured. The TDGCMS method is sensitive to 50 analytes. Hence TDGCMS is used in an initial survey of the site to determine what compounds are present and at what concentration. Once the major constituents of the soil-gas vapor plume are known the PAR can be configured to monitor for the five analytes of most interest. The PAR can analyse a sample in minutes, while in the field. The PAR is also quite precise in controlled situations.

Sollid, J.E.; Trujillo, V.L.; Limback, S.P.; Woloshun, K.A.

1995-12-01

272

Volatile organic compounds (VOCs) fingerprint of Alzheimer's disease.  

PubMed

Alzheimer's disease (AD) is a profoundly life changing condition and once diagnosis occurs, this is typically at a relatively late stage into the disease process. Therefore, a shift to earlier diagnosis, which means several decades before the onset of the typical manifestation of the disease, will be an important step forward for the patient. A promising diagnostic and screening tool to answer this purpose is represented by breath and exhaled volatile organic compounds (VOCs) analysis. In fact, human exhaled breath contains several thousand of VOCs that vary in abundance and number in correlation with the physiological status. The exhaled VOCs reflect the metabolism, including the neuronal ones, in healthy and pathological conditions. A growing number of studies clearly demonstrate the effectiveness of VOCs analysis in identifying pathologies, including neurodegenerative diseases. In the present study we recorded, in real time, breath parameters and exhaled VOCs. We were able to demonstrate a significant alteration in breath parameters induced by the pathology of AD. Further, we provide the putative VOCs fingerprint of AD. These vital findings are an important step toward the early diagnosis of AD. PMID:25308706

Mazzatenta, Andrea; Pokorski, Mieczyslaw; Sartucci, Ferdinando; Domenici, Luciano; Di Giulio, Camillo

2015-04-01

273

Predicting flammability of gas mixtures containing volatile organic compounds  

SciTech Connect

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

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

1997-12-31

274

Volatile organic compounds at swine facilities: a critical review.  

PubMed

Volatile organic compounds (VOCs) are regulated aerial pollutants that have environmental and health concerns. Swine operations produce and emit a complex mixture of VOCs with a wide range of molecular weights and a variety of physicochemical properties. Significant progress has been made in this area since the first experiment on VOCs at a swine facility in the early 1960s. A total of 47 research institutions in 15 North American, European, and Asian countries contributed to an increasing number of scientific publications. Nearly half of the research papers were published by U.S. institutions. Investigated major VOC sources included air inside swine barns, in headspaces of manure storages and composts, in open atmosphere above swine wastewater, and surrounding swine farms. They also included liquid swine manure and wastewater, and dusts inside and outside swine barns. Most of the sample analyses have been focusing on identification of VOC compounds and their relationship with odors. More than 500 VOCs have been identified. About 60% and 10% of the studies contributed to the quantification of VOC concentrations and emissions, respectively. The largest numbers of VOC compounds with reported concentrations in a single experimental study were 82 in air, 36 in manure, and 34 in dust samples. The relatively abundant VOC compounds that were quantified in at least two independent studies included acetic acid, butanoic acid (butyric acid), dimethyl disulfide, dimethyl sulfide, iso-valeric, p-cresol, propionic acid, skatole, trimethyl amine, and valeric acid in air. They included acetic acid, p-cresol, iso-butyric acid, butyric acid, indole, phenol, propionic acid, iso-valeric acid, and skatole in manure. In dust samples, they were acetic acid, propionic acid, butyric acid, valeric acid, p-cresol, hexanal, and decanal. Swine facility VOCs were preferentially bound to smaller-size dusts. Identification and quantification of VOCs were restricted by using instruments based on gas Chromatography (GC) and liquid chromatography (LC) with different detectors most of which require time-consuming procedures to obtain results. Various methodologies and technologies in sampling, sample preparation, and sample analysis have been used. Only four publications reported using GC based analyzers and PTR-MS (proton-transfer-reaction mass spectrometry) that allowed continuous VOC measurement. Because of this, the majority of experimental studies were only performed on limited numbers of air, manure, or dust samples. Many aerial VOCs had concentrations that were too low to be identified by the GC peaks. Although VOCs emitted from swine facilities have environmental concerns, only a few studies investigated VOC emission rates, which ranged from 3.0 to 176.5mgd(-1)kg(-1) pig at swine finishing barns and from 2.3 to 45.2gd(-1)m(-2) at manure storages. Similar to the other pollutants, spatial and temporal variations of aerial VOC concentrations and emissions existed and were significantly affected by manure management systems, barn structural designs, and ventilation rates. Scientific research in this area has been mainly driven by odor nuisance, instead of environment or health concerns. Compared with other aerial pollutants in animal agriculture, the current scientific knowledge about VOCs at swine facilities is still very limited and far from sufficient to develop reliable emission factors. PMID:22682363

Ni, Ji-Qin; Robarge, Wayne P; Xiao, Changhe; Heber, Albert J

2012-10-01

275

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

EPA Science Inventory

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

276

Respiration corrections for bacterial uptake of dissolved organic compounds in natural waters  

Microsoft Academic Search

The uptake of %-labeled organic compounds has been used by many workers to study heterotrophic microorganisms in natural waters. IIowevcr, if flux rates of organic com- pounds are to be mcasurcd, the loss of '\\

JOHN E. HOBBIE; CLAUDE C. CRAWFORD

1969-01-01

277

Geochemistry of volatile organic compounds in seawater: Mesocosm experiments with 14C-model compounds  

NASA Astrophysics Data System (ADS)

A series of ten radiotracer experiments were conducted in controlled experimental ecosystems (mesocosms) to investigate the behavior of volatile organic compounds (VOC) in seawater. Time-series measurements of the redistribution of 14C-activity within several major pools - dissolved, particulate, intermediate metabolite, and CO 2 - in the ecosystem made possible an evaluation of the rates of processes - volatilization, biodegradation, Sorption and sedimentation - acting to remove VOC from seawater in summer. The behavior of the model 14C-VOC fell into three categories. Aromatic hydrocarbons (benzene, toluene, naphthalene) were subject to both volatilization and biodegradation, with mineralization dominating in summer. Chlorinated C 2-hydrocarbons (tetrachloroethylene) and chlorinated benzenes (chlorobenzene, 1,4-dichlorobenzene, and 1,2,4-trichlorobenzene) were affected only by volatilization and were relatively resistant to biodegradation. Of all the model VOC studied, only aliphatic hydrocarbons (decane and octadecane) were sorbed onto suspended paniculate matter; however, the primary route of loss from the water column appeared to be biodegradation rather than sedimentation. The mesocosm-derived removal rate constants were then applied to estimate summer VOC residence times in Narragansett Bay, Rhode Island of about 1 day for aromatic hydrocarbons, 1 week for the chlorinated VOC and about 1 day for aliphatic hydrocarbons. Residence times in winter might be on the order of 1 week for all VOC.

Wakeham, Stuart G.; Canuel, Elizabeth A.; Doering, Peter H.

1986-06-01

278

Source apportionment modeling of volatile organic compounds in streams.  

PubMed

It often is of interest to understand the relative importance of the different sources contributing to the concentration c(w) of a contaminant in a stream; the portions related to sources 1, 2, 3, etc. are denoted c(w,1), c(w2), c(w3), etc. Like c(w), the fractions alpha1 = c(w,1)/c(w), alpha2 = c(w,2)/c(w), alpha3 = c(w,3)/c(w), etc. depend on location and time. Volatile organic compounds (VOCs) can undergo absorption from the atmosphere into stream water or loss from stream water to the atmosphere, causing complexities affecting the source apportionment (SA) of VOCs in streams. Two SA rules are elaborated. Rule 1: VOC entering a stream across the air/water interface exclusively is assigned to the atmospheric portion of c(w). Rule 2: VOC loss by volatilization, flow loss to groundwater, in-stream degradation, etc. is distributed over c(w,1), c(w,2), c(w3), etc. in proportion to their corresponding alpha values. How the two SA rules are applied, as well as the nature of the SA output for a given case, will depend on whether transport across the air/water interface is handled using the net flux F convention or using the individual fluxes J convention. Four hypothetical stream cases involving acetone, methyl-tert-butyl ether (MTBE), benzene, chloroform, and perchloroethylene (PCE) are considered. Acetone and MTBE are sufficiently water soluble from air for a domestic atmospheric source to be capable of yielding c(w) values approaching the common water quality guideline range of 1 to 10 microg/L. For most other VOCs, such levels cause net outgassing (F > 0). When F > 0 in a given section of stream, in the net flux convention, all of the alpha(j) for the compound remain unchanged over that section while c(w) decreases. A characteristic time tau(d) can be calculated to predict when there will be differences between SA results obtained by the net flux convention versus the individual fluxes convention. Source apportionment modeling provides the framework necessary for comparing different strategies for mitigating contamination at points of interest along a stream. PMID:16629131

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

2006-04-01

279

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

NASA Astrophysics Data System (ADS)

Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) to the atmosphere. A small number of studies have measured VOC emission from silage, but not enough is known about the processes involved to accurately quantify emission rates and identify practices that could reduce emissions. Through a literature review, we have focused on identifying the most important compounds emitted from corn silage (the most common type of silage in the US) and the sources of these compounds by quantifying their production and emission potential in silage and describing production pathways. We reviewed measurements of VOC emission from silage and assessed the importance of individual silage VOCs through a quantitative analysis of VOC concentrations within silage. Measurements of VOC emission from silage and VOCs present within silage indicated that alcohols generally make the largest contribution to emission from corn silage, in terms of mass emitted and potential ozone formation. Ethanol is the dominant alcohol in corn silage; excluding acids, it makes up more than half of the mean mass of VOCs present. Acids, primarily acetic acid, may be important when emission is high and all VOCs are nearly depleted by emission. Aldehydes and esters, which are more volatile than acids and alcohols, are important when exposure is short, limiting emission of more abundant but less volatile compounds. Variability in silage VOC concentrations is very high; for most alcohols and acids, tolerance intervals indicate that 25% of silages have concentrations a factor of two away from median values, and possibly much further. This observation suggests that management practices can significantly influence VOC concentrations. Variability also makes prediction of emissions difficult. The most important acids, alcohols, and aldehydes present in silage are probably produced by bacteria (and, in the case of ethanol, yeasts) during fermentation and storage of silage. Aldehydes may also be produced aerobically by spoilage microorganisms through the oxidation of alcohols. Abiotic reactions may be important for production of methanol and esters. Although silage additives appear to affect VOC production in individual studies, bacterial inoculants have not shown a consistent effect on ethanol, and effects on other VOCs have not been studied. Production of acetic acid is understood, and production could be minimized, but a decrease could lead to an increase in other, more volatile and more reactive, VOCs. Chemical additives designed for controlling yeasts and undesirable bacteria show promise for reducing ethanol production in corn silage. More work is needed to understand silage VOC production and emission from silage, including: additional measurements of VOC concentrations or production in silage of all types, and an exploration of the causes of variability; accurate on-farm measurements of VOC emission, including an assessment of the importance of individual ensiling stages and practices that could reduce emission of existing VOCs; and work on understanding the sources of silage VOCs and possible approaches for reducing production.

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

2013-10-01

280

Chlorinated and brominated persistent organic compounds in biological samples from the environment  

Microsoft Academic Search

Eleven selected biological samples representing different ecosystems, trophic levels, and areas mainly in Sweden have been analyzed for 31 halogenated organic compounds or compound groups. The multiresidue analytical method provides a good opportunity to compare the concentrations of the different compounds in the investigated samples. By the use of ratios of these concentrations, comparisons can be done between species and

Bo Jansson; Renate Andersson; Lillemor Asplund; K. Litzen; Kerstin Nylund; U. Sellstroem; Ulla-Britt Uvemo; Cajsa Wahlberg; Ulla Wideqvist; T. Odsjoe; Mats Olsson

1993-01-01

281

Mass transfer of nonvolatile organic compounds from porous media  

NASA Astrophysics Data System (ADS)

This thesis presents data pertaining to the mass transfer of nonvolatile organic compounds from porous media. Physical properties of porous solids, including surface and pore areas, are studied. Information from these studies, along with dissolution data, are used to develop correlations relating the Sherwood Number to the Peclet Number. The contaminant used in this study is naphthalene; the solids used are Moffett Sand (MS), Borden Sand (BS), Lampblack (LB), and Silica Gel (SG). Surface area results indicate that contamination at 0.1% reduces the area of MS and SG by 48 and 37%, respectively, while contamination at 1.0% reduces the area of MS, BS, and SG by 59, 56, and 40%, respectively. Most of the reduction in area originates in the reduction of pore areas and volumes, where the contaminant precipitates. After long-term storage, surface areas did not recover to their original values due to an "irreversible" fraction of naphthalene. Treatment with heat or solvent or both was necessary to completely remove the contamination. For lampblack, treatment at 100°C decreased areas while treatment at 250°C increased them. Treatment at 250°°C probably opened pores while that at 100°C may have blocked more pores by redistributing the tar-like contaminant characteristic of lampblack. Contaminated MS and SG solids are packed in columns through which water is pumped. The effluent began at a relatively high concentration (˜70% of solubility) for both samples. However, SG column concentrations dropped quickly, never achieving steady state while the MS samples declined more gradually towards steady state. The high pore areas of the SG samples are believed to cause this behavior. The steady state portion of the MS dissolution history is used to develop mass transfer correlations. The correlation in this study differs from previous work in two major ways: (1) the exponent on the Pe is three times larger and (2) the limiting Sh is 106 times smaller. These results suggest that the dissolution mechanism here is different than in other studies, that is, dissolution is occurring from the contaminated pores which are inaccessible to the flowing water. This work can be used to assess the leaching potential of non-volatile organic impacted soils. Also, soil vapor extraction schemes which are hampered by observed long tails can be explained using the data in this thesis.

Khachikian, Crist Simon

282

Production of volatile organic compounds in cultures of cryptophytes  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

283

Passive remediation of chlorinated volatile organic compounds using barometric pumping  

SciTech Connect

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

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

1993-12-31

284

Source apportionment of ambient volatile organic compounds in Hong Kong.  

PubMed

Volatile organic compounds (VOCs) were measured at four stations with different environments in Hong Kong (HK) during two sampling campaigns. Positive matrix factorization was applied to characterize major VOC sources in HK. Nine sources were identified, and the spatial and seasonal variations of their contributions were derived. The most significant local VOC sources are vehicle and marine vessel exhausts or liquefied petroleum gas (LPG) at different stations. Vehicle- and marine vessel-related sources accounted for 2.9-12.7ppbv in 2002-2003 and increased to 4.3-15.2ppbv in 2006-2007. Different from the emission inventory, solvent-related sources only contributed 11- 19% at both sampling campaigns. Therefore, emission control from transport sector should be prioritized to alleviate ambient local VOC levels. Additionally, the contribution of aged VOC, which roughly represents contributions from regional and super-regional transport, also showed moderate increase during the four years, indicating cooperation with environmental authorities in the Pearl River Delta and beyond should be strengthened. All the anthropogenic sources contribute most to Yuen Long and least to Tap Mun. However, Tap Mun exhibited different trends in comparison with the other three stations, especially for sources of vehicle and marine vessel exhausts, LPG and paint solvents. When the local source contributions were incorporated with wind data to derive the directional dependences of sources, we may conclude that the rapid development of Yantian Container Terminal, the associated emissions from marine vessels around the Terminal and the on-site activities were likely responsible for the distinct VOC features at Tap Mun. The current impact from the Terminal is mainly concentrated in the northeastern corner of HK; however, it has the potential threat to other locations if the Terminal continues to expand in such a rapid speed in the coming years. More stringent VOC control measures on activities related to the operation of the Terminal is therefore highly recommended. PMID:20554313

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

2010-09-01

285

Peat fires and air quality: volatile organic compounds and particulates.  

PubMed

There are numerous localized peat deposits on the Swan Coastal Plain, an urban and rural bioregion otherwise dominated by wetland ecosystems in southwestern Australia. Hydrological change is significant in the bioregion: urban development encroaches on wetlands, groundwater extraction provides the city population with most of its water, and rainfall declines will not recharge aquifers in the future. The wetland processes which contribute to the formation of these peat deposits have therefore changed and are becoming vulnerable to fire events with residents increasingly exposed to peat smoke. There is an imperative to characterise this peat smoke to determine if exposures are harmful or toxic, and opportunities to do so in this setting arise due to the absence of bushfire smoke which has confounded other international studies. We have measured volatile organic compounds (VOCs) and particulate concentrations from an opportunistic assessment of two peat fires. SUMMA canister grab samples and a portable GCMS were used to determine the VOCs with high 1h benzene concentrations of 16 and 30 ppm v/v. PM10 and PM2.5 particulate data were collected using an Osiris continuous analyser with 24h concentrations recorded at varying time periods (within a 5 months timeframe) ranging from 1h maximums of between 23-37 microgm(-3) for PM10 and 50.5-106 microgm(-3) for PM2.5. While the 24h averages were generally below national air quality standards, elevated 1h concentrations were observed on numerous occasions and on most days. Given the proximity of residential development to many peat deposits, a drying climate and the increased risk of arson in peri-urban environments, the health impacts of exposure to peat smoke need to be determined and if necessary measures developed to prevent exposure (which would include maintaining wetland sediment integrity so as to reduce its vulnerability to fire). PMID:19394676

Blake, D; Hinwood, A L; Horwitz, P

2009-07-01

286

[Ru/AC catalyzed ozonation of recalcitrant organic compounds].  

PubMed

Ozonation and Ru/AC catalyzed ozonation of dimethyl phthalate (DMP), phenols and disinfection by-products precursors were studied. It shows that Ru/AC catalyst can obviously enhance the mineralization of organic compounds. In the degradation of DMP, TOC removal was 28.84% by ozonation alone while it was 66.13% by catalytic ozonation. In the oxidation of 23 kinds of phenols, TOC removals were 9.57%-56.08% by ozonation alone while they were 41.81%-82.32% by catalytic ozonation. Compared to ozonation alone, Ru/AC catalyzed ozonation was more effective for the reduction of disinfection by-products formation potentials in source water. The reduction of haloacetic acids formation potentials was more obvious than thichlomethane formation potentials. After the treatment by catalytic ozonation, the haloacetic acids formation potentials decreased from 144.02 microg/L to 58.50 microg/L, which was below the standard value of EPA. However ozonation alone could not make it reach the standard. The treatments of source water by BAC, O3 + BAC, O3/AC + BAC and Ru/AC + O3 + BAC were also studied. In the four processes, TOC removal was 3.80%, 20.14%, 27.45% and 48.30% respectively, COD removal was 4.37%, 27.22%, 39.91% and 50.00% respectively, UV254 removal was 8.16%, 62.24%, 67.03% and 84.95% respectively. Ru/AC + O3 + BAC process is more effective than the other processes for the removal of TOC, COD and UV254 and no ruthenium leaching observed in the solution. It is a promising process for the treatment of micro polluted source water. PMID:19927805

Wang, Jian-Bing; Hou, Shao-Pei; Zhou, Yun-Rui; Zhu, Wan-Peng; He, Xu-Wen

2009-09-15

287

Sources of Volatile Organic Compounds (VOCs) in the UAE  

NASA Astrophysics Data System (ADS)

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

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

288

Analysis of industrial contaminants in indoor air: part 1. Volatile organic compounds, carbonyl compounds, polycyclic aromatic hydrocarbons and polychlorinated biphenyls.  

PubMed

This article reviews recent literature on the analysis of industrial contaminants in indoor air in the framework of the REACH project, which is mainly intended to improve protection of human health and the environment from the risks of more than 34 millions of chemical substances. Industrial pollutants that can be found in indoor air may be of very different types and origin, belonging to the volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) categories. Several compounds have been classified into the priority organic pollutants (POPs) class such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/PCDFs) and related polychlorinated compounds, and polycyclic aromatic hydrocarbons (PAHs). Many of these compounds are partially associated to the air gas phase, but also to the suspended particulate matter. Furthermore, settled dust can act as a concentrator for the less volatile pollutants and has become a matrix of great concern for indoors contamination. Main literature considered in this review are papers from the last 10 years reporting analytical developments and applications regarding VOCs, aldehydes and other carbonyls, PCBs, PCDDs, PCDFs, and PAHs in the indoor environment. Sample collection and pretreatment, analyte extraction, clean-up procedures, determination techniques, performance results, as well as compound concentrations in indoor samples, are summarized and discussed. Emergent contaminants and pesticides related to the industrial development that can be found in indoor air are reviewed in a second part in this volume. PMID:19019381

Barro, Ruth; Regueiro, Jorge; Llompart, María; Garcia-Jares, Carmen

2009-01-16

289

Characterization of microbial species in a regenerative bio-filter system for volatile organic compound removal  

Microsoft Academic Search

Effective removal of volatile organic compounds is critical for indoor air quality control. The performance of traditional technologies of volatile organic compound removal is limited by inadequate selection of filter media, poor airflow management inside the cleaning devices, insufficient catalytic reaction surface area, and poor distribution of UV light irradiation. In comparison, the relatively new regenerative air filtration systems use

Wen-Hsuan Huang; Zhiqiang Wang; Geetika Choudhary; Beverly Guo; Jianshun Zhang; Dacheng Ren

2012-01-01

290

Quantitative Analysis of Organic Compounds: A Simple and Rapid Method for Use in Schools  

ERIC Educational Resources Information Center

Describes the procedure for making a quantitative analysis of organic compounds suitable for secondary school chemistry classes. Using the Schoniger procedure, the organic compound, such as PVC, is decomposed in a conical flask with oxygen. The products are absorbed in a suitable liquid and analyzed by titration. (JR)

Schmidt, Hans-Jurgen

1973-01-01

291

Removal of hydrophobic Volatile Organic Compounds1 in an integrated process coupling Absorption and2  

E-print Network

1 Removal of hydrophobic Volatile Organic Compounds1 in an integrated process coupling Absorption, the treatment of atmospheric58 emission, including Volatile Organic Compounds, has become an ecological integrated process, silicone oils and ionic liquids.33 Key words: Hydrophobic VOC; Absorption; Two

Boyer, Edmond

292

Supplementary Material1 "The Atmospheric Potential of Biogenic Volatile Organic Compounds from Needles of2  

E-print Network

1 Supplementary Material1 "The Atmospheric Potential of Biogenic Volatile Organic Compounds from degradation of volatile organic compounds, Chem. Rev., 103,26 4605-4638, 2003.27 Hoskovec, M., Grygarova, D. The retention time and8 mass spectrum of -phellandrene were obtained using Angelica seed oil (Shiono Koryo9

Meskhidze, Nicholas

293

Origin of organic compounds on the primitive earth and in meteorites  

Microsoft Academic Search

Summary The role and relative contributions of different forms of energy to the synthesis of amino acids and other organic compounds on the primitive earth, in the parent bodies or carbonaceous chondrites, and in the solar nebula are examined. A single source of energy or a single process would not account for all the organic compounds synthesized in the solar

Stanley L. Miller; Harold C. Urey; J. Oró

1976-01-01

294

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

EPA Science Inventory

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

295

Assessing transformation processes of organic contaminants by compound-specific stable isotope analysis  

Microsoft Academic Search

The analysis of variations in stable isotope composition is becoming an essential approach for evaluating enzymatic and abiotic reactions of organic contaminants in soils and aquatic systems. Different, sometimes complementary analytical techniques are currently used and developed to determine stable isotope ratios in individual organic compounds. Anticipating an increasing demand for compound-specific isotope analysis, this survey compiles information for choosing

Thomas B. Hofstetter; Michael Berg

2011-01-01

296

Geochemical constraints on the origin of organic compounds in hydrothermal systems  

Microsoft Academic Search

It is proposed that abiotic synthesis of organic compounds occurs in metastable states. These states are permitted by kinetic barriers which inhibit the approach to stable equilibrium in the C-H-O-N system. Evidence for metastable equilibrium among organic compounds in sedimentary basins is reviewed, and further evidence is elucidated from hydrous pyrolysis experiments reported in the literature. This analysis shows that

Everett L. Shock

1990-01-01

297

Mathematical modeling of atmospheric fine particle-associated primary organic compound concentrations  

Microsoft Academic Search

An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped diesel trucks, paved road dust,

Wolfgang F. Rogge; Lynn M. Hildemann; Monica A. Mazurek; Glen R. Cass; Bernd R. T. Simoneit

1996-01-01

298

Mathematical modeling of atmospheric fine particle-associated primary organic compound concentrations  

Microsoft Academic Search

An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped autos, diesel trucks, paved road

Wolfgang F. Rogge; Lynn M. Hildemann; Monica A. Mazurek; Glen R. Cass; Bernd R. T. Simoneit

1996-01-01

299

Chlorinated Volatile Organic Compounds—Old, However, Actual Analytical and Toxicological Problem  

Microsoft Academic Search

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

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

2010-01-01

300

Adsorption of organic compounds pertinent to urban environments onto mineral dust particles  

Microsoft Academic Search

The interaction of mineral dust particles from the Sahara with semivolatile organic compounds over an urban region in Israel's coastal plain was studied. Dust samples were collected during numerous dust storm events in 2000 and 2001, under varying meteorological conditions. Organic compounds adsorbed on collected mineral dust particles were analyzed using an integrated, multitechnique study that employed a scanning electron

Alla H. Falkovich; Gal Schkolnik; Eliezer Ganor; Yinon Rudich

2004-01-01

301

Contributions of biogenic volatile organic compounds to net ecosystem carbon flux in a ponderosa pine plantation  

E-print Network

of carbon assimilated by an ecosystem is defined as the gross primary productivity (GPP). MuchContributions of biogenic volatile organic compounds to net ecosystem carbon flux in a ponderosa 2012 Keywords: Biogenic volatile organic compounds Net ecosystem exchange Carbon balance a b s t r a c

Cohen, Ronald C.

302

SOIL SORPTION OF VOLATILE AND SEMIVOLATILE ORGANIC COMPOUNDS IN A MIXTURE  

EPA Science Inventory

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

303

Temperature dependence of volatile organic compound evaporative emissions from motor vehicles  

E-print Network

summer 2001. Additional gasoline- related VOC emissions not shown in Figure 1 occur at service stationsTemperature dependence of volatile organic compound evaporative emissions from motor vehicles Juli tailpipe sources to motor vehicle volatile organic compound (VOC) emissions. Contributions were determined

Silver, Whendee

304

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

NASA Astrophysics Data System (ADS)

The functionalization of porous metal-organic frameworks (Cu 3( BTC) 2) was achieved by incorporating Keggin-type polyoxometalates (POMs), and further optimized via alkali metal ion-exchange. In addition to thermal gravimetric analysis, IR, single-crystal X-ray diffraction, and powder X-ray diffraction, the adsorption properties were characterized by N 2 and volatile organic compounds (VOCs) adsorption measurements, including short-chain alcohols ( C<4), cyclohexane, benzene, and toluene. The adsorption enthalpies estimated by the modified Clausius-Clapeyron equation provided insight into the impact of POMs and alkali metal cations on the adsorption of VOCs. The introduction of POMs not only improved the stability, but also brought the increase of adsorption capacity by strengthening the interaction with gas molecules. Furthermore, the exchanged alkali metal cations acted as active sites to interact with adsorbates and enhanced the adsorption of VOCs.

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

2011-11-01

305

Detection of Volatile Organic Compounds by Weight-Detectable Sensors coated with Metal-Organic Frameworks  

PubMed Central

Detection of volatile organic compounds (VOCs) using weight-detectable quartz microbalance and silicon-based microcantilever sensors coated with crystalline metal-organic framework (MOF) thin films is described in this paper. The thin films of two MOFs were grown from COOH-terminated self-assembled monolayers onto the gold electrodes of sensor platforms. The MOF layers worked as the effective concentrators of VOC gases, and the adsorption/desorption processes of the VOCs could be monitored by the frequency changes of weight-detectable sensors. Moreover, the MOF layers provided VOC sensing selectivity to the weight-detectable sensors through the size-selective adsorption of the VOCs within the regulated nanospace of the MOFs. PMID:25175808

Yamagiwa, Hiroki; Sato, Seiko; Fukawa, Tadashi; Ikehara, Tsuyoshi; Maeda, Ryutaro; Mihara, Takashi; Kimura, Mutsumi

2014-01-01

306

MULTISPECTRAL IDENTIFICATION AND CONFIRMATION OF ORGANIC COMPOUNDS IN WASTEWATER EXTRACTS  

EPA Science Inventory

Application of multispectral identification techniques to samples from industrial and POTW wastewaters revealed identities of 63 compounds that had not been identified by empirical matching of mass spectra with spectral libraries. wenty-five of the compounds had not been found in...

307

Prevention of marine biofouling using natural compounds from marine organisms  

Microsoft Academic Search

All surfaces that are submerged in the sea rapidly become covered by a biofilm. This process, called biofouling, has substantial economic consequences. Paints containing tri-butyl-tin (TBT) and copper compounds are used to protect marine structures by reducing biofouling. However, these compounds have damaging effects on the marine environment, as they are not biodegradable. It has been noted that many seaweeds

Evelyn Armstrong; Kenneth G. Boyd; J. Grant Burgess

2000-01-01

308

Organic compounds in the aqueous extract of a retorted Green River Formation oil shale  

Microsoft Academic Search

Spent oil shale (Green River Formation) from a Paraho directly fired retort was extracted with distilled\\/deionized water for 28 days at ambient temperature. The aqueous extract was then analyzed by gas chromatography\\/mass spectrometry for volatile and semi-volatile organic compounds using EPA hazardous chemicals identification technology. Organic compounds identified were predominantly carboxylic acids, although neutral and basic compounds were also observed.

J. F. McKay

1988-01-01

309

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

Microsoft Academic Search

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

Philip Neal Anderson

1995-01-01

310

How does predation affect the bioaccumulation of hydrophobic organic compounds in aquatic organisms?  

PubMed

It is well-known that the body burden of hydrophobic organic compounds (HOCs) increases with the trophic level of aquatic organisms. However, the mechanism of HOC biomagnification is not fully understood. To fill this gap, this study investigated the effect of predation on the bioaccumulation of polycyclic aromatic hydrocarbons (PAHs), one type of HOC, in low-to-high aquatic trophic levels under constant freely dissolved PAH concentrations (1, 5, or 10 ?g L(-1)) maintained by passive dosing systems. The tested PAHs included phenanthrene, anthracene, fluoranthene, and pyrene. The test organisms included zebrafish, which prey on Daphnia magna, and cichlids, which prey on zebrafish. The results revealed that for both zebrafish and cichlids, predation elevated the uptake and elimination rates of PAHs. The increase of uptake rate constant ranged from 20.8% to 39.4% in zebrafish with the amount of predation of 5 daphnids per fish per day, and the PAH uptake rate constant increased with the amount of predation. However, predation did not change the final bioaccumulation equilibrium; the equilibrium concentrations of PAHs in fish only depended on the freely dissolved concentration in water. Furthermore, the lipid-normalized water-based bioaccumulation factor of each PAH was constant for fish at different trophic levels. These findings infer that the final bioaccumulation equilibrium of PAHs is related to a partition between water and lipids in aquatic organisms, and predation between trophic levels does not change bioaccumulation equilibrium but bioaccumulation kinetics at stable freely dissolved PAH concentrations. This study suggests that if HOCs have not reached bioaccumulation equilibrium, biomagnification occurs due to enhanced uptake rates caused by predation in addition to higher lipid contents in higher trophic organisms. Otherwise, it is only due to the higher lipid contents in higher trophic organisms. PMID:25794043

Xia, Xinghui; Li, Husheng; Yang, Zhifeng; Zhang, Xiaotian; Wang, Haotian

2015-04-21

311

The composition of the primitive atmosphere and the synthesis of organic compounds on the early Earth  

NASA Technical Reports Server (NTRS)

The generally accepted theory for the origin of life on the Earth requires that a large variety of organic compounds be present to form the first living organisms and to provide the energy sources for primitive life either directly or through various fermentation reactions. This can provide a strong constraint on discussions of the formation of the Earth and on the composition of the primitive atmosphere. In order for substantial amounts of organic compounds to have been present on the prebiological Earth, certain conditions must have existed. There is a large body of literature on the prebiotic synthesis of organic compounds in various postulated atmospheres. In this mixture of abiotically synthesized organic compounds, the amino acids are of special interest since they are utilized by modern organisms to synthesize structural materials and a large array of catalytic peptides.

Bada, J. L.; Miller, S. L.

1985-01-01

312

A survey of household products for volatile organic compounds  

NASA Astrophysics Data System (ADS)

A total of 1159 common household products were analysed for 31 volatile organic compounds as potential sources of indoor air pollution. The products were distributed among 65 product categories within 8 category classes: automotive products (14.4% of the products); household cleaners/polishes (9.6%); paint-related products (39.9%); fabric and leather treatments (7.9%); cleaners for electronic equipment (6.0%); oils, greases and lubricants (9.6%); adhesive-related products (6.6%); and miscellaneous products (6.1%). The study was conducted in two parts. In the first part, or the original study, the products were reanalysed for methylene chloride and five other chlorocarbons using purge-and-trap gas chromatography/mass spectrometry (GC/MS), and a data base containing the analytical results was developed. Because full mass spectra were taken, the original set of GC/MS data also contained information regarding other volatile chemicals in the products. However, this additional data was not reported at that time. In the second part of the study, the GC/MS data were reanalysed to determine the presence and concentrations of an additional 25 volatile chemicals. The 31 chemicals included in both parts of this study were: carbon tetrachloride; methylene chloride; tetrachloroethylene; 1,1,1-trichloroethane; trichlorethylene; 1,1,2-tricholorotrifluoroethane; acetone; benzene; 2-butanone; chlorobenzene; chloroform; cyclohexane; 1,2-dichloroethane; 1,4-dioxane; ethylbenzene; n-hexane; d-limonene; methylcyclohexane; methylcyclopentane; methyl isobutyl ketone; n-nonane; n-octane; ?-pinene; propylene oxide; styrene; 1,1,2,2-tetrachloroethane; tetrahydrofuran; toluene; m-mxylene; o-xylene; and p-xylene. Of the 31 chemicals, toluene, the xylenes and methylene chloride were found to occur most frequently—in over 40% of the products tested. Chemicals that were typically found in relatively high concentrations in the samples (i.e. greater than 20% w/w) included acetone, 2-butanone, hexane, methylene chloride, tetrachloroethylene, toluene, 1,1,1-trichloroethane, trichloroethylene, 1,1,2-trichlorotrifluoroethane and the xylenes. Chlorobenzene, d-limonene, 1,1,2,2-tetrachloroethane, n-nonane and styrene were not found in any of the products at or above the 0.1% level. In all, 935 of the products contained one or more of the target solvents at levels greater than 0.1%. The resulting data base contains information regarding the 1159 products, such as origin, cost, container type, lot number, etc., as well as quantitative information for each of the 31 chemicals. The frequency of occurrence and average concentrations for the target chemicals are summarized for each of the product classes.

Sack, Thomas M.; Steele, David H.; Hammerstrom, Karen; Remmers, Janet

313

Airborne flux measurements of biogenic volatile organic compounds over California  

NASA Astrophysics Data System (ADS)

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 coniferous forests were extremely low, high concentrations of methanol and monoterpenes were found above some of these regions. These observations demonstrate the ability to measure fluxes from specific sources by eddy covariance from an aircraft, and suggest the utility of measurements using fast response chemical sensors to constrain emission inventories and map out source distributions for a much broader array of trace gases than was observed in this study. This paper reports the first regional direct eddy covariance fluxes of isoprene. The emissions of VOCs measured from aircraft with 2 km spatial resolution can quantify the distribution of major sources providing the observations required for testing statewide emission inventories of these important trace gases. These measurements will be used in a future study to assess BVOC emission models and their driving variable datasets.

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

2014-03-01

314

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

SciTech Connect

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/or spills that might have resulted in groundwater contamination in this sediment, although several relatively small accidental releases of VOCs have occurred in the past in the northern portion of the 300 Area. It is likely that large quantities of degreasing solutions were disposed to the North and South Process Ponds during the 1950s and 1960s, and that evidence for them in the upper portion of the unconfined aquifer has been removed because of groundwater movement through the much more transmissive sediment. Also, investigations to date have revealed no evidence to suggest that a dense, non-aqueous phase liquid remains undetected in the subsurface. Potential pathways for contamination to migrate from this finer-grained sediment include groundwater movement through the interval to offshore locations in the Columbia River channel, dispersion out of the finer-grained interval into the overlying transmissive sediment (again, with transport to the riverbed), and potential future withdrawal via water supply wells.

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

2008-07-07

315

Source apportionment of volatile organic compounds measured in Edmonton, Alberta  

NASA Astrophysics Data System (ADS)

From 2003 to 2009, whole air samples were collected at two sites in Edmonton and analyzed for over 77 volatile organic compounds (VOCs). VOCs were sampled in the downtown area (Central site) and an industrial area on the eastern side of the city (East site). Concentrations of most VOCs were highest at the East site, with an average total VOC mass concentration of 221 ?g m-3. The average total VOC mass concentration at the Central site was 65 ?g m-3. The United States Environmental Protection Agency's positive matrix factorization receptor model (EPA PMF) was used to apportion ambient concentrations of VOCs into eleven factors, which were associated with emissions sources. On average, 94 and 99% of the measured mass were apportioned by PMF at the East and Central site, respectively. Factors include transportation combustion (gasoline and diesel), industrial sources (industrial evaporative, industrial feedstock, gasoline production/storage, industrial chemical use), mixed mobile and industrial (gasoline evaporative, fugitive butane), a biogenic source, a natural gas related source, and a factor that was associated with global background pollutants transported into the area. Transportation sources accounted for more than half of the reconstructed VOC mass concentration at the Central site, but less than 10% of the reconstructed mass concentration at the East site. By contrast, industrial sources accounted for ten times more of the reconstructed VOC mass concentration at the East site than at the Central site and were responsible for approximately 75% of the reconstructed VOC mass concentration observed at the East site. Of the six industrial factors identified at the East site, four were linked to petrochemical industry production and storage. The two largest contributors to the reconstructed VOC mass concentration at the East site were associated with fugitive emissions of volatile species (butanes, pentanes, hexane, and cyclohexane); together, these two factors accounted for more than 50% of the reconstructed VOC mass concentration at the East site in contrast to less than 2% of the reconstructed mass concentration at the Central site. Natural gas related emissions accounted for 10%-20% of the reconstructed mass concentration at both sites. Biogenic emissions and VOCs associated with well-mixed global background were less than 10% of the reconstructed VOC mass concentration at the Central site and less than 3% of the reconstructed mass concentration at the East site.

McCarthy, Michael C.; Aklilu, Yayne-Abeba; Brown, Steven G.; Lyder, David A.

2013-12-01

316

INVESTIGATIONS OF BIODEGRADABILITY AND TOXICITY OF ORGANIC COMPOUNDS  

EPA Science Inventory

The development of elaborate industrial societies has led to proliferation of a vast number of complex chemicals for industrial, agricultural and domestic use. Some portion of these compounds eventually find their way into municipal and industrial wastewater. Unless specifically ...

317

INFLUENCE OF SURFACTANTS ON MICROBIAL DEGRADATION OF ORGANIC COMPOUNDS  

EPA Science Inventory

Surfactants have the ability to increase aqueous concentrations of poorly soluble compounds and interfacial areas between immiscible fluids, thus potentially improving the accessibility of these substrates to microorganisms. However, both enhancements and inhibitions of biodegrad...

318

INFLUENCE OF SURFACTANTS OF MICROBIAL DEGRADATION OF ORGANIC COMPOUNDS  

EPA Science Inventory

Surfactants have the ability to increase aqueous concentrations o poorly soluble compounds and interfacial areas between immiscible fluids, thus potentially improving the accessibility of these substrates to microorganisms. owever, both enhancements and inhibitions of biodegradat...

319

The Separation and Identification of Two Unknown Solid Organic Compounds: An Experiment for the Sophomore Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

Segregation and recognition of two unfamiliar concrete organic compounds are achieved through microscale flash chromatography and spectroscopy plus melting point verifications respectively. This inexpensive and harmless microscale experiment for sophomore students ensures exercise in chromatographic and spectroscopic methods.

Feist, Patty L.

2004-01-01

320

Interaction of organic compounds with calcium carbonate--III. Amino acid composition of sorbed layers  

Microsoft Academic Search

Nitrogenous organic compounds in sorbed surface layers and in calcified organic matter associated with calcium carbonate sediment particles consist of 40-50% amino acids, 2% amino sugars and 25% ammonia. In grain size classes > 20 m these compounds are mainly contained in the calcified protein of carbonate secreting organisms but with smaller grain sizes--and consequently increased specific surface area--they are

Peter J. Müller; Erwin Suess

1977-01-01

321

Determination of Semivolatile Organic Compounds in Particles in the Grand Canyon Area  

Microsoft Academic Search

Several diffusion denuder-filter-sorbent bed and filter-sorbent bed sampling systems with varying selectivity for the collection of different classes of organic compounds have been used for the collection and determination of atmospheric organic material present at Hopi Point in the Grand Canyon. The data show that the amount of semivolatile organic compounds in particles in the atmosphere in the Southwest United

Delbert J. Eatough; Brenda Sedar; Laura Lewis; Lee D. Hansen; Edwin A. Lewis; Robert J. Farber

1989-01-01

322

Methods and systems for chemoautotrophic production of organic compounds  

DOEpatents

The present disclosure identifies pathways, mechanisms, systems and methods to confer chemoautotrophic production of carbon-based products of interest, such as sugars, alcohols, chemicals, amino acids, polymers, fatty acids and their derivatives, hydrocarbons, isoprenoids, and intermediates thereof, in organisms such that these organisms efficiently convert inorganic carbon to organic carbon-based products of interest using inorganic energy, such as formate, and in particular the use of organisms for the commercial production of various carbon-based products of interest.

Fischer, Curt R.; Che, Austin J.; Shetty, Reshma P.; Kelly, Jason R.

2013-01-08

323

Sonochemical degradation of various monocyclic aromatic compounds: relation between hydrophobicities of organic compounds and the decomposition rates.  

PubMed

Various aromatic compounds, i.e., nitrobenzene, aniline, phenol, benzoic acid, salicylic acid, 2-chlorophenol, 4-chlorophenol, styrene, chlorobenzene, toluene, ethylbenzene and n-propylbenzene were decomposed under identical ultrasonic irradiation conditions. The relationships between the initial rates of degradation of these aromatic compounds and their physicochemical parameters were systematically investigated. It was revealed that some correlations between the degradation rates and parameters of volatility, Henry's law constant and vapor pressure, were observed only in the limited high range of parameters. It was suggested that the Henry's law constant and vapor pressure had influenced on the rate of degradation for some of the tested aromatic compounds. In contrast, better correlations between the initial rates of degradation and hydrophobic parameters, water solubility and LogP (water-octanol partition coefficient), were observed over the wide range of chosen parameters. These results meant that the hydrophobicity of the compounds significantly affected their accumulation at the gas-liquid interface of the bubbles and it was the most important factor for the sonochemical degradation of aromatic compounds. In particular, for the sonolysis of water-insoluble organic compounds, LogP was found to be the representative parameter for understanding the hydrophobic properties of water-insoluble compounds. PMID:17706451

Nanzai, Ben; Okitsu, Kenji; Takenaka, Norimichi; Bandow, Hiroshi; Maeda, Yasuaki

2008-04-01

324

Degradation and mineralization of organic UV absorber compound 2-phenylbenzimidazole-5-sulfonic acid (PBSA) using UV-254nm/H2O2.  

PubMed

Various studies have revealed the non-biodegradable and endocrine disrupting properties of sulfonated organic UV absorbers, directing people's attention toward their risks on ecological and human health and hence their removal from water. In this study, UV-254nm/H2O2 advanced oxidation process (AOP) was investigated for degrading a model UV absorber compound 2-phenylbenzimidazole-5-sulfonic acid (PBSA) and a structurally similar compound 1H-benzimidazole-2-sulfonic acid (BSA), with a specific focus on their mineralization. At 4.0mM [H2O2]0, a complete removal of 40.0?M parent PBSA and 25% decrease in TOC were achieved with 190min of UV irradiation; SO4(2-) was formed and reached its maximum level while the release of nitrogen as NH4(+) was much lower (around 50%) at 190min. Sulfate removal was strongly enhanced by increasing [H2O2]0 in the range of 0-4.0mM, with slight inhibition in 4.0-12.0mM. Faster and earlier ammonia formation was observed at higher [H2O2]0. The presence of Br(-) slowed down the degradation and mineralization of both compounds while a negligible effect on the degradation was observed in the presence of Cl(-). Our study provides important technical and fundamental results on the HO based degradation and mineralization of SO3H and N-containing UV absorber compounds. PMID:25123523

Abdelraheem, Wael H M; He, Xuexiang; Duan, Xiaodi; Dionysiou, Dionysios D

2015-01-23

325

Quantum chemical calculations for polymers and organic compounds  

NASA Technical Reports Server (NTRS)

The relativistic effects of the orbiting electrons on a model compound were calculated. The computational method used was based on 'Modified Neglect of Differential Overlap' (MNDO). The compound tetracyanoplatinate was used since empirical measurement and calculations along "classical" lines had yielded many known properties. The purpose was to show that for large molecules relativity effects could not be ignored and that these effects could be calculated and yield data in closer agreement to empirical measurements. Both the energy band structure and molecular orbitals are depicted.

Lopez, J.; Yang, C.

1982-01-01

326

EMISSION OF ORGANIC COMPOUNDS AND COMBUSTION GASES DURING HAZARDOUSWASTE COFIRING IN A WATERTUBE PACKAGE BOILER  

EPA Science Inventory

The primary objective of this study was to evaluate the sorptionand desorption of organic compounds on combustion-generated sootduring the cofiring of hazardous organics with fuel oil in afull-scale boiler. orption of organics was accomplished by firinga watertube package boiler ...

327

Factors affecting bioabsorption, metabolism, and storage of organic compounds by aquatic biota  

Microsoft Academic Search

Biological concentration and transfer of organic chemicals through aquatic food webs can be influenced by a variety of environmental, biological, and biochemical factors. Bioaccumulation can be significantly altered by the presence of suspended matter or complex organic mixtures in the water column. In addition, the bioaccumulation factor of a compound is dependent on the species of an organism, its life

R. M. Bean; D. D. Dauble; B. L. Thomas; R. W. Hanf; E. K. Chess

1985-01-01

328

Reactive uptake of ozone by liquid organic compounds  

NASA Astrophysics Data System (ADS)

The reaction probability of ozone on the surface of several different organic liquids is measured. Ozone reacts efficiently (??10-2-10-3) with organic liquids containing double bonds (1-tridecene, ?-pinene, toluene, methacrolein and canola oil), and much less efficiently with an aldehyde, a ketone (tridecanal, 2-tridecanone; ??10-4), an alkane, an alcohol and an acid (tridecane, 1-tridecanol, tridecanoic acid; ??10-5). The results suggest that heterogeneous reactions with organic aerosol can be an important loss process for tropospheric ozone, if the aerosol contains unsaturated organic material.

de Gouw, Joost A.; Lovejoy, Edward R.

329

ORGANIC COMPOUNDS IN AN INDUSTRIAL WASTEWATER. THEIR TRANSPORT INTO SEDIMENTS  

EPA Science Inventory

The wastewater from a small specialty chemicals manufacturing plant located on the Pawtuxet River (Rhode Island, USA) has contaminated the water and sediment of that river, the Pawtuxet Cove, the Providence River, and (to a lesser extent) the Narragansett Bay. Since the compounds...

330

Green Synthetic Alternatives to Organic Compounds and Nanomaterials  

EPA Science Inventory

A brief account of reactions involving microwave (MW) exposure of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ?doped? versions, for the rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermedia...

331

Identification of organic compounds on diesel engine soot  

Microsoft Academic Search

Several studies have shown that extracts of soot collected from light-duty diesel engines cause mutations in bacteria and mammalian cells both with and without metabolic activation. To help identify the specific compounds responsible for these biological effects, the detailed chemical composition of one such extract by gas chromatographic mass spectrometry was investigated. The two most mutagenic fractions contain alkylated phenanthrenes,

Ming-Li. Yu; Ronald A. Hites

1981-01-01

332

In situ measurements of gas/particle-phase transitions for atmospheric semivolatile organic compounds  

PubMed Central

An understanding of the gas/particle-phase partitioning of semivolatile compounds is critical in determining atmospheric aerosol formation processes and growth rates, which in turn affect global climate and human health. The Study of Organic Aerosol at Riverside 2005 campaign was performed to gain a better understanding of the factors responsible for aerosol formation and growth in Riverside, CA, a region with high concentrations of secondary organic aerosol formed through the phase transfer of low-volatility reaction products from the oxidation of precursor gases. We explore the ability of the thermal desorption aerosol gas chromatograph (TAG) to measure gas-to-particle-phase transitioning for several organic compound classes (polar and nonpolar) found in the ambient Riverside atmosphere by using in situ observations of several hundred semivolatile organic compounds. Here we compare TAG measurements to modeled partitioning of select semivolatile organic compounds. Although TAG was not designed to quantify the vapor phase of semivolatile organics, TAG measurements do distinguish when specific compounds are dominantly in the vapor phase, are dominantly in the particle phase, or have both phases present. Because the TAG data are both speciated and time-resolved, this distinction is sufficient to see the transition from vapor to particle phase as a function of carbon number and compound class. Laboratory studies typically measure the phase partitioning of semivolatile organic compounds by using pure compounds or simple mixtures, whereas hourly TAG phase partitioning measurements can be made in the complex mixture of thousands of polar/nonpolar and organic/inorganic compounds found in the atmosphere. PMID:20142511

Williams, Brent J.; Goldstein, Allen H.; Kreisberg, Nathan M.; Hering, Susanne V.

2010-01-01

333

THE INTERACTION OF VAPOUR PHASE ORGANIC COMPOUNDS WITH INDOOR SINKS  

EPA Science Inventory

The interaction of indoor air pollutants with interior surfaces (i.e., sinks) is a well known, but poorly understood, phenomenon. Studies have shown that re-emissions of adsorbed organic vapours can contribute to elevated concentrations of organics in indoor environments. Researc...

334

Organic compounds in the water column of the eastern Baltic  

SciTech Connect

This article describes the transport, distribution, concentration, chemistry, environmental consequences, and chemical control strategies of organic wastes--including waste hydrocarbons, industrial effluents and oil spills--in the Baltic Sea and in the regions along its shorelines. Data on seasonal and compositional variations in organic waste content are provided.

Nemirovskaya, I.A.; Nesterova, M.P.; Pustel'nikov, O.S.

1987-11-01

335

A LABORATORY STUDY OF ARSENATE REDUCTION BY ORGANIC COMPOUNDS  

EPA Science Inventory

A variety of organic reductants will be explored. Initial studies will focus on molecules possessing alpha-hydroxy carboxylate and phenolate functional groups, organic groups commonly found in reducing environments. Mandelic acid was chosen as the alpha-hydroxy carboxylate sinc...

336

METHODS OF REDUCING WATER CONTAMINANTS: REMOVAL OF ORGANIC COMPOUNDS  

EPA Science Inventory

Much of the recent concern by regulatory agencies about drinking water quality has been directed toward organic contamination in drinking water. lthough organic contamination has been thought to primarily affect surface waters, there is a growing awareness and concern over ground...

337

A luminescent metal-organic framework constructed using a tetraphenylethene-based ligand for sensing volatile organic compounds.  

PubMed

By using a tetraphenylethene (TPE)-based ligand, tetrakis[4-(4-carboxyphenyl)phenyl]ethene (H4TCPPE), a porous metal-organic framework [Zn2(TCPPE)] (1) is synthesized, which exhibits strong fluorescence and is capable of gas adsorption and sensing volatile organic compounds. PMID:25502496

Liu, Xun-Gao; Wang, Hui; Chen, Bin; Zou, Yang; Gu, Zhi-Guo; Zhao, Zujin; Shen, Liang

2015-01-31

338

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

E-print Network

, polyols and alkanes to quantify oxidized BVOCs. Terpene and isoprene oxidation products were amongSecondary organic aerosols formed from oxidation of biogenic volatile organic compounds and terpenes, can be oxidized to form less volatile carbonyls, acids, and multifunctional oxygenated products

Cohen, Ronald C.

339

MECHANISTIC ROLES OF SOIL HUMUS AND MINERALS IN THE SORPTION OF NONIONIC ORGANIC COMPOUNDS FROM AQUEOUS AND ORGANIC SOLUTIONS  

EPA Science Inventory

Mechanistic roles of soil humus and soil minerals and their contributions to soil sorption of nonionic organic compounds from aqueous and organic solutions are illustrated. Parathion and lindane are used as model solutes on two soils that differ greatly in their humic and mineral...

340

Oil-field emissions of volatile organic compounds. Final report, April 1988-March 1989  

SciTech Connect

This report presents data that determine the composition of volatile organic compound emissions from oil production fields in Tulsa County, Oklahoma. Five points in the crude-oil production process were samples: well heads, gathering tasks, oilfield pipeline tanks, pipeline terminal tanks, and refinery crude-oil storage tanks. The samples were collected in Summa polished stainless steel canisters and analyzed by a gas chromatograph with dual flame ionization detectors. The analytical technique looked for ninety specific compounds; thirty were detected and are reported. In general the compounds in greatest abundance were ethane, propane, n-butane, 2-methyl butane, and n-pentane. The data developed are for the composition of the volatile organic compounds; volatile organic-compound emission rates were not determined.

Viswanath, R.S.; Van Sandt, J.H.

1989-04-01

341

Charge-density matching in organic–inorganic uranyl compounds  

Microsoft Academic Search

Single crystals of [C10H26N2][(UO2)(SeO4)2(H2O)](H2SeO4)0.85(H2O)2 (1), [C10H26N2][(UO2)(SeO4)2] (H2SeO4)0.50(H2O) (2), and [C8H20N]2[(UO2)(SeO4)2(H2O)] (H2O) (3) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amines. The structures of the compounds have been solved by direct methods and structural models have been obtained. The structures of the compounds 1, 2, and 3 contain U and Se atoms in

Sergey V. Krivovichev; Ivan G. Tananaev; Boris F. Myasoedov

2007-01-01

342

RELATIONSHIPS BETWEEN LEVELS OF VOLATILE ORGANIC COMPOUNDS IN AIR AND BLOOD FROM THE GENERAL POPULATION  

EPA Science Inventory

Background: The relationships between levels of volatile organic compounds (VOCs) in blood and air have not been well characterized in the general population where exposure concentrations are generally at ppb levels. Objectives: This study investigates relationships between ...

343

SOIL SORPTION OF VOLATILE AND SEMIVOLATILE ORGANIC COMPOUNDS IN A MIXTURE  

EPA Science Inventory

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

344

AUTOMATED CRYOGENIC PRECONCENTRATION AND GAS CHROMATOGRAPHIC DETERMINATION OF VOLATILE ORGANIC COMPOUNDS IN AIR  

EPA Science Inventory

The performances of two nominally identical automated monitors for quantifying volatile organic compounds were compared on identical ambient laboratory air samples. The monitors incorporate cryogenic preconcentration subunits specially designed for controlled release of liquid ni...

345

Plant-Associated Bacterial Degradation of Toxic Organic Compounds in Soil  

PubMed Central

A number of toxic synthetic organic compounds can contaminate environmental soil through either local (e.g., industrial) or diffuse (e.g., agricultural) contamination. Increased levels of these toxic organic compounds in the environment have been associated with human health risks including cancer. Plant-associated bacteria, such as endophytic bacteria (non-pathogenic bacteria that occur naturally in plants) and rhizospheric bacteria (bacteria that live on and near the roots of plants), have been shown to contribute to biodegradation of toxic organic compounds in contaminated soil and could have potential for improving phytoremediation. Endophytic and rhizospheric bacterial degradation of toxic organic compounds (either naturally occurring or genetically enhanced) in contaminated soil in the environment could have positive implications for human health worldwide and is the subject of this review. PMID:19742157

McGuinness, Martina; Dowling, David

2009-01-01

346

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

Code of Federal Regulations, 2013 CFR

...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a) On and...

2013-07-01

347

Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air  

E-print Network

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 ...

Scholten, Elke

348

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

EPA Science Inventory

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

349

ESTIMATION OF PHYSICAL PROPERTIES AND CHEMICAL REACTIVITY PARAMETERS OF ORGANIC COMPOUNDS  

EPA Science Inventory

The computer program SPARC (Sparc Performs Automated Reasoning in Chemistry)has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms ...

350

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

EPA Science Inventory

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

351

POLAR ORGANIC COMPOUNDS IN FINE PARTICLES FROM THE NEW YORK, NEW JERSEY, AND CONNECTICUT REGIONAL AIRSHED  

EPA Science Inventory

Five key scientific questions guiding this research were explored. They are given here with results generated from the project.   B.1.        How can polar organic compounds be measured in atmospheric fine particulate matter? Is there potential a...

352

LITERATURE REVIEW OF PERSONAL AIR MONITORS FOR POTENTIAL USE IN AMBIENT AIR MONITORING OF ORGANIC COMPOUNDS  

EPA Science Inventory

The open literature, Federal publications, industrial reports, and other sources published between 1975 and 1980 were reviewed for information relevant to personal air samplers potentially useful in sampling organic compounds at ambient levels (50-200 ppt). Seventy one references...

353

PATTERN RECOGNITION STUDIES OF HALOGENATED ORGANIC COMPOUNDS USING CONDUCTING POLYMER SENSOR ARRAYS. (R825323)  

EPA Science Inventory

Direct measurement of volatile and semivolatile halogenated organic compounds of environmental interest was carried out using arrays of conducting polymer sensors. Mathematical expressions of the sensor arrays using microscopic polymer network model is described. A classical, non...

354

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

EPA Science Inventory

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

355

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

Code of Federal Regulations, 2012 CFR

...Petroleum Liquids for Which Construction, Reconstruction, or Modification Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic compounds (VOC). (a) The owner or operator of each storage vessel...

2012-07-01

356

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

Code of Federal Regulations, 2011 CFR

...Petroleum Liquids for Which Construction, Reconstruction, or Modification Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic compounds (VOC). (a) The owner or operator of each storage vessel...

2011-07-01

357

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

Code of Federal Regulations, 2010 CFR

...Petroleum Liquids for Which Construction, Reconstruction, or Modification Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic compounds (VOC). (a) The owner or operator of each storage vessel...

2010-07-01

358

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

Code of Federal Regulations, 2014 CFR

...Petroleum Liquids for Which Construction, Reconstruction, or Modification Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic compounds (VOC). (a) The owner or operator of each storage vessel...

2014-07-01

359

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

Code of Federal Regulations, 2013 CFR

...Petroleum Liquids for Which Construction, Reconstruction, or Modification Commenced After May 18, 1978, and Prior to July 23, 1984 § 60.112a Standard for volatile organic compounds (VOC). (a) The owner or operator of each storage vessel...

2013-07-01

360

EVALUATION USING AN ORGANOPHILIC CLAY TO CHEMICALLY STABILIZE WASTE CONTAINING ORGANIC COMPOUNDS  

EPA Science Inventory

A modified clay (organophilic) was utilized to evaluate the potential for chemically stabilizing a waste containing organic compounds. hemical bonding between the binder and the contaminants was indicated. eachate testing also indicated strong binding. Copy available at NTIS as ...

361

AUTOMATED CRYOGENIC SAMPLING AND GAS CHROMATOGRAPHIC ANALYSIS OF AMBIENT VAPOR-PHASE ORGANIC COMPOUNDS: SYSTEM DESIGN  

EPA Science Inventory

An automated system for unattended repetitive sampling and analysis of volatile organic compounds has been designed and a prototype constructed. The sampling/analysis scheme involves reduced temperature preconcentration of analytes from whole air with subsequent thermal desorptio...

362

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

363

METHODOLOGY FOR DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND OTHER SEMIVOLATILE ORGANIC COMPOUNDS IN HOUSE DUST  

EPA Science Inventory

Analytical methods were validated to determine polycyclic aromatic hydrocarbons (PAH) and other semivolatile organic compounds in house dust. e also examined the storage stability of three potential markers (solanesol, nicotine, and continine) for particulate-phase environmental ...

364

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

EPA Science Inventory

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

365

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

EPA Science Inventory

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

366

ANALYTICAL REFERENCE STANDARDS AND SUPPLEMENTAL DATA FOR PESTICIDES AND OTHER ORGANIC COMPOUNDS  

EPA Science Inventory

;Contents: List of available pesticide standards and ordering information; Compounds deleted from 1978 stock and name changes; List of non-pesticide organic chemical standards; Safe handling of primary reference standards; Preparation and storage of reference standards; Decoding ...

367

TREATMENT OF CHLORINATED VOLATILE ORGANIC COMPOUNDS IN UPFLOW WETLAND MESOCOSMS. (R828773C003)  

EPA Science Inventory

Sorption, biodegradation and hydraulic parameters were determined in the laboratory for two candidate soil substrate mixtures for construction of an upflow treatment wetland for volatile organic compounds (VOCs) at a Superfund site. The major parent contaminants in the groundw...

368

Measurements of Volatile Organic Compounds Using Proton Transfer Reaction - Mass Spectrometry during the MILAGRO 2006 Campaign  

E-print Network

Volatile organic compounds (VOCs) were measured by proton transfer reaction – mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of ...

Fortner, E. C.

369

SUPERCRITICAL FLUID EXTRACTION-GAS CHROMATOGRAPHY OF VOLATILE ORGANIC COMPOUNDS (VOC) FROM TENAX DEVICES  

EPA Science Inventory

The report describes the development and evaluation of on-line supercritical fluid extraction-gas chromatography instrumentation and methodology for the analysis of volatile organic compounds (VOC) from adsorbent sampling devices. Supercritical fluid extraction offers potential a...

370

PREDICTION OF THE VAPOR PRESSURE, BOILING POINT, HEAT OF VAPORIZATION AND DIFFUSION COEFFICIENT OF ORGANIC COMPOUNDS  

EPA Science Inventory

The prototype computer program SPARC has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC solute-solute physical process models have been developed and tested...

371

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

EPA Science Inventory

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

372

PREDICTION OF CHEMICAL REACTIVITY PARAMETERS AND PHYSICAL PROPERTIES OF ORGANIC COMPOUNDS FROM MOLECULAR STRUCTURE USING SPARC  

EPA Science Inventory

The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

373

Detection, Composition and Treatment of Volatile Organic Compounds from Waste Treatment Plants  

PubMed Central

Environmental policies at the European and global level support the diversion of wastes from landfills for their treatment in different facilities. Organic waste is mainly treated or valorized through composting, anaerobic digestion or a combination of both treatments. Thus, there are an increasing number of waste treatment plants using this type of biological treatment. During waste handling and biological decomposition steps a number of gaseous compounds are generated or removed from the organic matrix and emitted. Different families of Volatile Organic Compounds (VOC) can be found in these emissions. Many of these compounds are also sources of odor nuisance. In fact, odors are the main source of complaints and social impacts of any waste treatment plant. This work presents a summary of the main types of VOC emitted in organic waste treatment facilities and the methods used to detect and quantify these compounds, together with the treatment methods applied to gaseous emissions commonly used in composting and anaerobic digestion facilities. PMID:22163835

Font, Xavier; Artola, Adriana; Sánchez, Antoni

2011-01-01

374

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

EPA Science Inventory

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

375

Transformations of halogenated organic compounds under denitrification conditions.  

PubMed Central

Trihalomethanes, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dibromoethane, chlorinated benzenes, ethylbenzene, and naphthalene at concentrations commonly found in surface and groundwater were incubated under anoxic conditions to study their transformability in the presence of denitrifying bacteria. None of the aromatic compounds showed significant utilization relative to sterile controls at initial concentrations from 41 to 114 micrograms/liter after 11 weeks of incubation. Of the halogenated aliphatic compounds studied, transformations of carbon tetrachloride and brominated trihalomethanes were observed after 8 weeks in batch denitrification cultures. Carbon from the decomposition of carbon tetrachloride was both assimilated into cell material and mineralized to carbon dioxide. How this was possible remains unexplained, since carbon tetrachloride is transformed to CO2 by hydrolysis and not by oxidation-reduction. Chloroform was detected in bacterial cultures with carbon tetrachloride initially present, indicating that reductive dechlorination had occurred in addition to hydrolysis. The data suggest that transformations of certain halogenated aliphatic compounds are likely to occur under denitrification conditions in the environment. PMID:6859850

Bouwer, E J; McCarty, P L

1983-01-01

376

ORGANIC COMPOUNDS MEASURED IN PM2.5 DURING NEOPS  

EPA Science Inventory

Secondary formation of submicron ambient particulate matter occurs when organic and inorganic constituents having sufficiently low volatility condense onto preexisting particles in the atmosphere. The presence of the resulting submicron particles has led to three important env...

377

Heterogeneous Photocatalysis for Control of Volatile Organic Compounds in Indoor Air  

Microsoft Academic Search

Research results concerning the photocatalytic activity and selectivity of benzene are discussed. This compound, which represents one of an important class of volatile organic compounds found in indoor air, was oxidized in an annular photocatalytic reactor featuring a thin film of titanium dioxide and illuminated by a fluorescent black light. The gas phase products, carbon dioxide and carbon monoxide, were

William A. Jacoby; Daniel M Blake; John A. Penned; James E. Boulter; LeAnn M. Vargo; Marya C George; Suzanne K. Dolberg

1996-01-01

378

COMPENDIUM OF METHODS FOR THE DETERMINATION OF TOXIC ORGANIC COMPOUNDS IN AMBIENT AIR  

EPA Science Inventory

Determination of toxic organic compounds in ambient air is a complex task, primarily because of the wide variety of compounds of interest and the lack of standardized sampling and analysis procedures. This compendium of methods has been prepared to provide current, peer-reviewed ...

379

Emissions of volatile organic compounds from vegetation and the implications for atmospheric chemistry  

Microsoft Academic Search

Vegetation provides a major source of reactive carbon entering the atmosphere. These compounds play an important role in (1) shaping global tropospheric chemistry, (2) regional photochemical oxidant formation, (3) balancing the global carbon cycle, and (4) production of organic acids which contribute to acidic deposition in rural areas. Present estimates place the total annual global emission of these compounds between

Fred Fehsenfeld; Jack Calvert; Ray Fall; Paul Goldan; A. B. Guenther; C. N. Hewitt; Brian Lamb; Shaw Liu; Michael Trainer; Hal Westberg; Pat Zimmerman

1992-01-01

380

Delivery of Complex Organic Compounds from Planetary Nebulae to the Solar System  

Microsoft Academic Search

Infrared spectroscopic observations of planetary nebulae and proto-planetary nebulae have shown that complex organic compounds are synthesized in these objects over periods as short as a thousand years. These compounds are ejected into the interstellar medium and spread throughout the Galaxy. Evidence from meteorites has shown that these stellar grains have reached the Solar System, and may have showered the

Sun Kwok

2009-01-01

381

Phenolic compounds and fatty acid composition of organic and conventional grown pecan kernels  

Technology Transfer Automated Retrieval System (TEKTRAN)

In this study, differences in contents of phenolic compounds and fatty acids in pecan kernels of organically versus conventionally grown pecan cultivars (‘Desirable’, ‘Cheyenne’, and ‘Wichita’) were evaluated. Although we were able to identify nine phenolic compounds (gallic acid, catechol, catechin...

382

Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds  

Microsoft Academic Search

Samples of water and sediment from a conventional drinking-water-treatment (DWT) plant were analyzed for 113 organic compounds (OCs) that included pharmaceuticals, detergent degradates, flame retardants and plasticizers, polycyclic aromatic hydrocarbons (PAHs), fragrances and flavorants, pesticides and an insect repellent, and plant and animal steroids. 45 of these compounds were detected in samples of source water and 34 were detected in

Paul E. Stackelberg; Jacob Gibs; Edward T. Furlong; Michael T. Meyer; Steven D. Zaugg; R. Lee Lippincott

2007-01-01

383

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

EPA Science Inventory

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

384

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

EPA Science Inventory

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

385

Diurnal and Seasonal Variability of Gasoline-Related Volatile Organic Compounds in Riverside, CA  

Microsoft Academic Search

On and off-road mobile source emissions are the dominant contributor to urban anthropogenic volatile organic compound (AVOC) emissions. Analyses of speciated gasoline samples from California for both summer and winter indicate significant differences in chemical composition due to intentional seasonal adjustments to liquid fuel composition. Ambient air measurements of ~60 compounds, including VOCs, were measured via in-situ gas chromatography during

D. R. Gentner; R. A. Harley; A. M. Miller; A. H. Goldstein

2008-01-01

386

Ultraviolet combustion of dissolved organic nitrogen compounds in lake waters  

Microsoft Academic Search

Ultraviolet combustion of lake waters combined with sensitive spectrophotometric NO, + NO,-N and NH,-N analyses offers a loo-fold increase in sensitivity over the micro-Kjeldahl method for total dissolved organic nitrogen. The procedure permits quantification of two organic nitrogen fractions in lake waters based on the relative rate and amounts of labile NH4-N and refractory NOa + NO,-N released. Combustions of

B. A. MANNY; M. C. MILLER; R. G. WETZEL

1971-01-01

387

Acidic organic compounds in beverage, food, and feed production.  

PubMed

Organic acids and their derivatives are frequently used in beverage, food, and feed production. Acidic additives may act as buffers to regulate acidity, antioxidants, preservatives, flavor enhancers, and sequestrants. Beneficial effects on animal health and growth performance have been observed when using acidic substances as feed additives. Organic acids could be classified in groups according to their chemical structure. Each group of organic acids has its own specific properties and is used for different applications. Organic acids with low molecular weight (e.g. acetic acid, lactic acid, and citric acid), which are part of the primary metabolism, are often produced by fermentation. Others are produced more economically by chemical synthesis based on petrochemical raw materials on an industrial scale (e.g. formic acid, propionic and benzoic acid). Biotechnology-based production is of interest due to legislation, consumer demand for natural ingredients, and increasing environmental awareness. In the United States, for example, biocatalytically produced esters for food applications can be labeled as "natural," whereas identical conventional acid catalyst-based molecules cannot. Natural esters command a price several times that of non-natural esters. Biotechnological routes need to be optimized regarding raw materials and yield, microorganisms, and recovery methods. New bioprocesses are being developed for organic acids, which are at this time commercially produced by chemical synthesis. Moreover, new organic acids that could be produced with biotechnological methods are under investigation for food applications. PMID:24275825

Quitmann, Hendrich; Fan, Rong; Czermak, Peter

2014-01-01

388

Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments  

SciTech Connect

The theoretical potential for the formation of clusters of vapor-phase organic compounds found in indoor air around the [sup 218]PoO[sub x][sup +] ion was investigated as well as which compounds were most likely to form clusters. A compilation of measurements of indoor organic compounds has been made for future experiments and theoretical calculations by the radon research community. Forty-four volatile and semivolatile organic compounds out of the more than 300 that have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the [sup 218]PoO[sub x][sup +] ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones, and the acetates) and the semivolatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos). Although the estimated diameters are consistent with the measured diameters for the unattached fraction, the state of experimental and theoretical knowledge in this area is not sufficiently developed to judge the quantitative validity of these predictions. 48 refs., 1 fig., 5 tabs.

Daisey, J.M. (Lawrence Berkeley Lab., CA (United States)); Hopke, P.K. (Clarkson Univ., Potsdam, NY (United States))

1993-07-01

389

Enhanced extraction of polychlorinated organic compounds from soil samples by fluidized-bed extraction (FBE)  

Microsoft Academic Search

Summary  The extraction and determination of polychlorinated organic compounds, like hexachlorobenzene, pentachlorobenzene, octachlorostyrene\\u000a and polychlorinated biphenyls in soils and solid wastes continues to be a subject for study. In this work Soxhlet extraction\\u000a and a new extraction technique, fluidized-bed extraction, have been compared. The extraction of polychlorinated organic compounds\\u000a by this technique has been optimized using experiemental design procedures. The variation

M. Gfrerer; M. Stadlober; B. M. Gawlik; T. Wenzl; E. Lankmayr

2001-01-01

390

Catalytic combustion of volatile organic compounds on gold\\/cerium oxide catalysts  

Microsoft Academic Search

Catalytic combustion of some representative volatile organic compounds (VOCs) (2-propanol, methanol and toluene) was investigated on gold\\/cerium oxide catalysts prepared by coprecipitation (CP) and deposition–precipitation (DP). The presence of gold has been found to enhance the activity of cerium oxide towards the oxidation of the selected volatile organic compounds, the extent of this effect depending on the preparation method of

Salvatore Scirè; Simona Minicò; Carmelo Crisafulli; Cristina Satriano; Alessandro Pistone

2003-01-01

391

Characterization of the solvent extractable organic compounds in PM2.5 aerosols in Hong Kong  

Microsoft Academic Search

The results from a year-long monthly study of the solvent extractable organic compounds (SEOC) in PM2.5 of the ambient aerosols in Hong Kong are reported. A total of 18 samples were analyzed. The extracted organic compounds were separated into four major fractions (n-alkanes, fatty acids, alkanols and PAHs (polycyclic aromatic hydrocarbons)) and identified with GC-MS (gas chromatography–mass spectrometry). The percentage

Mei Zheng; Ming Fang; Fu Wang; K. L. To

2000-01-01

392

Screening Processed Milk for Volatile Organic Compounds Using Vacuum Distillation\\/Gas Chromatography\\/Mass Spectrometry  

Microsoft Academic Search

An adaptation is presented of method 8261—from the Office of Solid Waste and Emergency Response Test Methods for Evaluating Solid Waste Physical\\/Chemical Methods (SW-846)—to analyze milk for an expanded list of volatile organic compounds is presented. The milk matrix exhibits a strong affinity for organic compounds and the surrogate based matrix normalization described in method 8261 provided accurate results. This

M. H. Hiatt; J. H. Pia

2004-01-01

393

Human-induced changes in US biogenic volatile organic compound emissions: evidence from long-term forest  

E-print Network

Human-induced changes in US biogenic volatile organic compound emissions: evidence from long Road, Durham, NH 03824-3525, USA Abstract Volatile organic compounds (VOCs) emitted by woody vegetation organic compounds (VOCs) emitted by vegeta- tion are important chemical species that affect the oxidative

Moorcroft, Paul R.

394

Fate of pharmaceutical and trace organic compounds in three septic system plumes, Ontario, Canada.  

PubMed

Three high volume septic systems in Ontario, Canada, were examined to assess the potential for onsite wastewatertreatment systems to release pharmaceutical compounds to the environment and to evaluate the mobility of these compounds in receiving aquifers. Wastewater samples were collected from the septic tanks, and groundwater samples were collected below and down gradient of the infiltration beds and analyzed for a suite of commonly used pharmaceutical and trace organic compounds. The septic tank samples contained elevated concentrations of several pharmaceutical compounds. Ten of the 12 compounds analyzed were detected in groundwater at one or more sites at concentrations in the low ng L(-1) to low microg L(-1) range. Large differences among the sites were observed in both the number of detections and the concentrations of the pharmaceutical compounds. Of the compounds analyzed, ibuprofen, gemfibrozil, and naproxen were observed to be transported atthe highest concentrations and greatest distances from the infiltration source areas, particularly in anoxic zones of the plumes. PMID:18497127

Carrara, Cherilyn; Ptacek, Carol J; Robertson, William D; Blowes, David W; Moncur, Michael C; Sverko, Ed; Backus, Sean

2008-04-15

395

Solvent-based dissolution method to sample gas-phase volatile organic compounds for compound-specific isotope analysis.  

PubMed

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 ?(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 ?(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. PMID:24360256

Bouchard, Daniel; Hunkeler, Daniel

2014-01-17

396

Mobilization and Transport of Organic Compounds from Reservoir Rock and Caprock in Geological Carbon Sequestration Sites  

SciTech Connect

Supercritical CO2 (scCO2) is an excellent solvent for organic compounds, including benzene, toluene, ethyl-benzene, and xylene (BTEX), phenols, and polycyclic aromatic hydrocarbons (PAHs). Monitoring results from geological carbon sequestration (GCS) field tests has shown that organic compounds are mobilized following CO2 injection. Such results have raised concerns regarding the potential for groundwater contamination by toxic organic compounds mobilized during GCS. Knowledge of the mobilization mechanism of organic compounds and their transport and fate in the subsurface is essential for assessing risks associated with GCS. Extraction tests using scCO2 and methylene chloride (CH2Cl2) were conducted to study the mobilization of volatile organic compounds (VOCs, including BTEX), the PAH naphthalene, and n-alkanes (n-C20 – n-C30) by scCO2 from representative reservoir rock and caprock obtained from depleted oil reservoirs and coal from an enhanced coal-bed methane recovery site. More VOCs and naphthalene were extractable by scCO2 compared to the CH2Cl2 extractions, while scCO2 extractable alkane concentrations were much lower than concentrations extractable by CH2Cl2. In addition, dry scCO2 was found to extract more VOCs than water saturated scCO2, but water saturated scCO2 mobilized more naphthalene than dry scCO2. In sand column experiments, moisture content was found to have an important influence on the transport of the organic compounds. In dry sand columns the majority of the compounds were retained in the column except benzene and toluene. In wet sand columns the mobility of the BTEX was much higher than that of naphthalene. Based upon results determined for the reservoir rock, caprock, and coal samples studied here, the risk to aquifers from contamination by organic compounds appears to be relatively low; however, further work is necessary to fully evaluate risks from depleted oil reservoirs.

Zhong, Lirong; Cantrell, Kirk J.; Mitroshkov, Alexandre V.; Shewell, Jesse L.

2014-05-06

397

Deuterium enrichment by selective photo-induced dissociation of an organic carbonyl compound  

DOEpatents

A method for producing a deuterium enriched material by photoinduced dissociation which uses as the working material a gas phase photolytically dissociable organic carbonyl compound containing at least one hydrogen atom bonded to an atom which is adjacent to a carbonyl group and consisting of molecules wherein said hydrogen atom is present as deuterium and molecules wherein said hydrogen atom is present as another isotope of hydrogen. The organic carbonyl compound is subjected to intense infrared radiation at a preselected wavelength to selectively excite and thereby induce dissociation of the deuterium containing species to yield a deuterium enriched stable molecular product. Undissociated carbonyl compound, depleted in deuterium, is preferably redeuterated for reuse.

Marling, John B. (Livermore, CA)

1981-01-01

398

Clean process to destroy arsenic-containing organic compounds with recovery of arsenic  

DOEpatents

A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic. 1 fig.

Upadhye, R.S.; Wang, F.T.

1996-08-13

399

Clean process to destroy arsenic-containing organic compounds with recovery of arsenic  

DOEpatents

A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic.

Upadhye, Ravindra S. (Pleasanton, CA); Wang, Francis T. (Danville, CA)

1996-01-01

400

Detecting and Eliminating Interfering Organic Compounds in Waters Analyzed for Isotopic Composition by Crds  

NASA Astrophysics Data System (ADS)

Optical spectroscopy based CRDS technology for isotopic analysis of ?D and ?18O directly from liquid water has greatly increased the number and type of liquid samples analyzed. This increase has also revealed a previously unrecognized sample contamination problem. Recently West[1] and Brand[2] identified samples containing ethanol, methanol, plant extracts and other organic compounds analyzed by CRDS and other spectroscopy based techniques as yielding erroneous results for ?D and ?18O (especially ?D) due to spectroscopic interference. Not all organic compounds generate interference. Thus, identifying which samples are contaminated by which organic compounds is of key importance for data credibility and correction. To address this problem a new approach in the form of a software suite, ChemCorrect™, has been developed. A chemometrics component uses a spectral library of water isotopologues and interfering organic compounds to best fit the measured spectra. The best fit values provide a quantitative assay of the actual concentrations of the various species and are then evaluated to generate a visual flag indicating samples affected by organic contamination. Laboratory testing of samples spiked with known quantities of interfering organic compounds such as methanol, ethanol, and terpenes was performed. The software correctly flagged and identified type of contamination for all the spiked samples without any false positives. Furthermore the reported values were a linear function of actual concentration with an R^2>0.99 even for samples which contained multiple organic compounds. Further testing was carried out against a range of industrial chemical compounds which can contaminate ground water as well as a variety of plant derived waters and juices which were also analyzed by IRMS. The excellent results obtained give good insight into which organic compounds cause interference and which classes of plants are likely to contain interfering compounds. Finally approaches to minimize the effect of interfering compounds will be discussed including methods to assess the confidence level of an isotopic value obtained from a contaminated sample. [1] Rapid Commun. Mass Spectrom. 2010; 24: 1-7 [2] Rapid Commun. Mass Spectrom. 2009; 23: 1879-1884 Results from laboratory samples, most of which were spiked with interfering organic compounds. Samples are color coded as follows: blue=standard, green=no contamination, yellow=slight contamination, red=heavily contaminated.

Richman, B. A.; Hsiao, G. S.; Rella, C.

2010-12-01

401

ENZYMATIC PROCESSES USED BY PLANTS TO DEGRADE ORGANIC COMPOUNDS  

EPA Science Inventory

This is a review of recent plant enzyme systems that have been studied in uptake and transformation of organic contaminants. General procedures of plant preparation and enzyme isolation are covered. Six plant enzyme systems have been investigated for activity with selected pollut...

402

EFFECTS IN HUMANS OF A VOLATILE ORGANIC COMPOUND MIXTURE: SENSORY  

EPA Science Inventory

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

403

Anaerobic degradation of organic compounds at high salt concentrations  

Microsoft Academic Search

A number of obligately anaerobic fermentative bacteria are known to degrade a variety of organic substrates such as sugars, amino acids, and others, in the presence of high salt concentrations (up to 3–4 M) to products such as hydrogen, CO2, acetate and higher fatty acids, and ethanol. Our understanding of the fate of these products in hypersaline environments is still

Aharon Oren

1988-01-01

404

ORGANIC AND ORGANOTIN COMPOUNDS LEACHED FROM PVC AND CPVC PIPE  

EPA Science Inventory

The primary objective of this research program was to determine whether organotins, contained in heat stabilizers of polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) pipe, and other organics present in pipe sealing cement solvents may leach into potable water su...

405

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

PubMed Central

Objectives 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. Methods 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. Results 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. Conclusion 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. PMID:22953204

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

2011-01-01

406

Ion-trap detection of volatile organic compounds in alveolar breath  

SciTech Connect

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

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

1992-01-01

407

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

NASA Astrophysics Data System (ADS)

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

Isidorov, V. A.; Vinogorova, V. T.; Rafa?owski, K.

408

Assessment of synthetic organic compounds, and endocrinology and histology of carp in Lake Mead  

SciTech Connect

This study investigated the presence and biologic effects of synthetic organic compounds transported by Las Vegas Wash to Lake Mead National Recreation Area. Water, bottom sediment, and carp (Cyprinus carpio) were analyzed for synthetic organic compounds. Semipermeable membrane devices (SPMDs) were used to sample the water column. Blood samples were collected from Carp for analysis of sex steroid hormones and vitellogenin. Samples of external abnormalities and organs (liver, gill, kidney, small intestine, and gonad) were collected for histologic analysis. Compounds known to affect endocrine systems (PAHs, phthalate esters, PCBs, dioxins and furans) were detected in SPMD, bottom-sediment, and/or carp samples. The number and concentrations of compounds generally were greater in samples from Las Vegas Wash and Bay, than in samples from Callville Bay, a reference site in Lake Mead. High levels of PAHs detected in SPMDs from Callville Bay could indicate the existence of contaminant sources other than Las Vegas Wash.

Bevans, H.; Goodbred, S.; Miesner, J.

1995-12-31

409

Cooperative water-SOM interactions derived from the organic compound effect on SOM hydration  

NASA Astrophysics Data System (ADS)

Interactions of water molecules with soil organic matter (SOM) may affect the ability of SOM to participate in multiple physical, chemical and biological processes. Specifically, water-SOM interactions may have a profound effect on interactions of organic compounds with SOM which is often considered as a major natural sorbent controlling the environmental fate of organic pollutants in the soil environment. Quantification of water - SOM interactions may be carried out by using water vapor sorption isotherms. However, water sorption isotherms providing macroscopic thermodynamic data do not allow examining water-SOM interactions on a microenvironment scale. The examination of water-SOM interactions in a local SOM environment may be carried out by determining the response of the SOM hydration to sorption of probe organic compounds. Recently, the model-free approach was proposed which allows quantifying effects of sorbing organic molecules on water - SOM interactions, by using relatively more available data on the effect of water activity on organic compound - SOM interactions. Therefore, this thermodynamic approach was applied to the experimental data describing sorption of organic compounds by SOM, both from the vapor and liquid phases, at various water activities. Hence, the response of water interactions with the model SOM materials such as a humic acid and an organic matter-rich peat soil to the presence of various organic sorbates was evaluated. Depending on a molecular structure of organic sorbates probing various molecular environments in SOM, the SOM-bound water may be driven in or out of the SOM sorbents. Organic compounds containing the atoms of oxygen, nitrogen or sulfur and preferring a relatively "polar" SOM microenvironment demonstrate the distinct enhancing effect on water-SOM interactions. In contrast, the "low-polarity" organic compounds, e.g., hydrocarbons or their halogen-substituted derivatives, produce a weakening effect on water-SOM interactions. Importantly, the changes in water-SOM interactions induced by the presence of organic compounds may demonstrate the cooperative behavior: (1) several water molecules may be involved in an enhanced hydration of SOM, (2) at the presence of an organic sorbate, interactions of water molecules with SOM enhance the uptake of the following water molecules. The proposed cooperative water-SOM interactions may result from a perturbation of the SOM matrix due to a sorption of organic and water molecules where a partial disrupting of molecular contacts in SOM makes easier the following SOM-water interactions thus promoting the enhanced SOM hydration.

Borisover, Mikhail

2014-05-01

410

Hygroscopicity of organic compounds from biomass burning and their influence on the water uptake of mixed organic ammonium sulfate aerosols  

NASA Astrophysics Data System (ADS)

Hygroscopic behavior of organic compounds, including levoglucosan, 4-hydroxybenzoic acid, and humic acid, as well as their effects on the hygroscopic properties of ammonium sulfate (AS) in internally mixed particles are studied by a hygroscopicity tandem differential mobility analyzer (HTDMA). The organic compounds used represent pyrolysis products of wood that are emitted from biomass burning sources. It is found that humic acid aerosol particles only slightly take up water, starting at RH (relative humidity) above ~70%. This is contrasted by the continuous water absorption of levoglucosan aerosol particles in the range 5-90% RH. However, no hygroscopic growth is observed for 4-hydroxybenzoic acid aerosol particles. Predicted water uptake using the ideal solution theory, the AIOMFAC model and the E-AIM (with UNIFAC) model are consistent with measured hygroscopic growth factors of levoglucosan. However, the use of these models without consideration of crystalline organic phases is not appropriate to describe the hygroscopicity of organics that do not exhibit continuous water uptake, such as 4-hydroxybenzoic acid and humic acid. Mixed aerosol particles consisting of ammonium sulfate and levoglucosan, 4-hydroxybenzoic acid, or humic acid with different organic mass fractions, take up a reduced amount of water above 80% RH (above AS deliquescence) relative to pure ammonium sulfate aerosol particles of the same mass. Hygroscopic growth of mixtures of ammonium sulfate and levoglucosan with different organic mass fractions agree well with the predictions of the thermodynamic models. Use of the Zdanovskii-Stokes-Robinson (ZSR) relation and AIOMFAC model lead to good agreement with measured growth factors of mixtures of ammonium sulfate with 4-hydroxybenzoic acid assuming an insoluble organic phase. Deviations of model predictions from the HTDMA measurement are mainly due to the occurrence of a microscopical solid phase restructuring at increased humidity (morphology effects), which are not considered in the models. Hygroscopic growth factors of mixed particles containing humic acid are well reproduced by the ZSR relation. Lastly, the organic surrogate compounds represent a selection of some of the most abundant pyrolysis products of biomass burning. The hygroscopic growths of mixtures of the organic surrogate compounds with ammonium sulfate with increasing organics mass fraction representing ambient conditions from the wet to the dry seasonal period in the Amazon basin, exhibit significant water uptake prior to the deliquescence of ammonium sulfate. The measured water absorptions of mixtures of several organic surrogate compounds (including levoglucosan) with ammonium sulfate are close to those of binary mixtures of levoglucosan with ammonium sulfate, indicating that levoglucosan constitutes a major contribution to the aerosol water uptake prior to (and beyond) the deliquescence of ammonium sulfate. Hence, certain hygroscopic organic surrogate compounds can substantially affect the deliquescence point of ammonium sulfate and overall particle water uptake.

Lei, T.; Zuend, A.; Wang, W. G.; Zhang, Y. H.; Ge, M. F.

2014-10-01

411

A review of surface-water sediment fractions and their interactions with persistent manmade organic compounds  

USGS Publications Warehouse

This paper reviews the suspended and surficial sediment fractions and their interactions with manmade organic compounds. The objective of this review is to isolate and describe those contaminant and sediment properties that contribute to the persistence of organic compounds in surface-water systems. Most persistent, nonionic organic contaminants, such as the chlorinated insecticides and polychlorinated biphenyls (PCBs), are characterized by low water solubilities and high octanol-water partition coefficients. Consequently, sorptive interactions are the primary transformation processes that control their environmental behavior. For nonionic organic compounds, sorption is primarily attributed to the partitioning of an organic contaminant between a water phase and an organic phase. Partitioning processes play a central role in the uptake and release of contaminants by sediment organic matter and in the bioconcentration of contaminants by aquatic organisms. Chemically isolated sediment fractions show that organic matter is the primary determinant of the sorptive capacity exhibited by sediment. Humic substances, as dissolved organic matter, contribute a number of functions to the processes cycling organic contaminants. They alter the rate of transformation of contaminants, enhance apparent water solubility, and increase the carrying capacity of the water column beyond the solubility limits of the contaminant. As a component of sediment particles, humic substances, through sorptive interactions, serve as vectors for the hydrodynamic transport of organic contaminants. The capabilities of the humic substances stem in part from their polyfunctional chemical composition and also from their ability to exist in solution as dissolved species, flocculated aggregates, surface coatings, and colloidal organomineral and organometal complexes. The transport properties of manmade organic compounds have been investigated by field studies and laboratory experiments that examine the sorption of contaminants by different sediment size fractions. Field studies indicate that organic contaminants tend to sorb more to fine-grained sediment, and this correlates significantly with sediment organic matter content. Laboratory experiments have extended the field studies to a wider spectrum of natural particulates and anthropogenic compounds. Quantitation of isotherm results allows the comparison of different sediment sorbents as well as the estimation of field partition coefficients from laboratory-measured sediment and contaminant properties. Detailed analyses made on the basis of particle-size classes show that all sediment fractions need to be considered in evaluating the fate and distribution of manmade organic compounds. This conclusion is based on observations from field studies and on the variety of natural organic sorbents that demonstrate sorptive capabilities in laboratory isotherm experiments.

Witkowski, P.J.; Smith, J.A.; Fusillo, T.V.; Chiou, C.T.

1987-01-01

412

Biosynthesis of polybrominated aromatic organic compounds by marine bacteria  

PubMed Central

Polybrominated diphenyl ethers (PBDEs) and polybrominated bipyrroles are natural products that bioaccumulate in the marine food chain. PBDEs have attracted widespread attention due to their persistence in the environment and potential toxicity to humans. However, the natural origins of PBDE biosynthesis are not known. Here we report marine bacteria as producers of PBDEs and establish a genetic and molecular foundation for their production that unifies paradigms for the elaboration of bromophenols and bromopyrroles abundant in marine biota. We provide biochemical evidence of marine brominase enzymes revealing decarboxylative-halogenation enzymology previously unknown among halogenating enzymes. Biosynthetic motifs discovered in our study were used to mine sequence databases to discover unrealized marine bacterial producers of organobromine compounds. PMID:24974229

Agarwal, Vinayak; El Gamal, Abrahim A.; Yamanaka, Kazuya; Poth, Dennis; Kersten, Roland D.; Schorn, Michelle; Allen, Eric E.; Moore, Bradley S.

2014-01-01

413

Volatile organic compounds at a coastal site. 1. Seasonal variations  

SciTech Connect

Alkylaromatics, alkanes, aldehydes, dimethyl polysulfides, and miscellaneous compounds were determined over a 15-month period at a coastal site. Alkylbenzenes appear dominated by anthropogenic inputs and air-sea exchange, with selective biodegradation showing minor effects in the summer. Offshore mixing and adsorption to sediments seems minor. Alkylnaphthalenes showed a contrasting pattern, best explained by a dominant wintertime source such as space heating oil use. Alkanes were frequently petroleum derived, but pentadecane, heptadecane, and pristane showed evidence of strong biogenic sources as well. The aldehydes exhibited complex behavior, with evidence for autooxidative as well as plankton sources. The dimethyl polysulfides had great variability; they may contribute significant sea-to-air sulfur fluxes if our measured levels are typical of the larger coastal region. An incompletely identified octatriene occurs briefly; it may be an algal product related to the pheromone ''fucoserraten''.

Gschwend, P.M.; Zafiriou, O.C.; Mantoura, R.F.C.; Schwarzenbach, R.P.; Gagosian, R.B.

1982-01-01

414

Thermoresponsive organic-inorganic hybrid large-compound vesicles.  

PubMed

Herein, gelated thermoresponsive large-compound vesicles (LCVs) are reported for the first time. The LCVs are prepared by self-assembly of poly(ethylene oxide)-block-poly[N-isopropylacrylamide-random-3-(trimethoxysilyl)propyl methacrylate] [PEO-b-P(NIPAM-r-TMPM)] in DMF-water mixture. Then, sol-gel reaction of the reactive PTMPM block is performed to stabilize the LCVs. LCVs with higher cross-linking density keep almost the same size under different temperatures while LCVs with lower cross-linking density display obviously thermoresponsive size transition between 22 and 36 °C. The gelated LCVs exhibit enhanced permeability with temperature elevation and their permeabilities at different temperatures all elevate with increasing the cross-linking density. PMID:23740858

Peng, Bo; Chen, Yongming

2013-07-25

415

Evaluation of control strategies for volatile organic compounds in indoor air (journal article)  

Microsoft Academic Search

The paper discusses research which evaluates the application of adsorption techniques to the control of indoor organic vapors. The adsorption on activated carbon of three compounds representing three classes of organic species was studied at 30 C in the concentration range zero to 200 ppb using a microbalance. The three were benzene (aromatic), acetaldehyde (oxygenated aliphatic), and 1,1,1-trichloroethane (halogenated aliphatic).

K. Ramanathan; V. L. Debler

1988-01-01

416

TECHNICAL ASSISTANCE DOCUMENT FOR SAMPLING AND ANALYSIS OF TOXIC ORGANIC COMPOUNDS IN AMBIENT AIR  

EPA Science Inventory

The guidance document was originally issued in June 1983. ince then significant changes have occurred in the regulations that cover volatile and semivolatile organic air pollutants. There have also been significant advances in the collection and analysis of organic compounds and ...

417

Mixing and water-soluble characteristics of particulate organic compounds in individual urban aerosol particles  

Microsoft Academic Search

Particulate organic compounds (POCs) in the atmosphere can alter the morphology and hygroscopicity of inorganic particles by coagulation and mixing. Direct observations can illustrate the mixing of organic and inorganic particles. Compositions, mixing states, and morphologies of 360 aerosol particles from urban Beijing collected on transmission electron microscopy (TEM) grids with Si-O substrate were obtained using TEM coupled with energy-dispersive

Weijun Li; Longyi Shao

2010-01-01

418

Distributions of brominated organic compounds in the troposphere and lower stratosphere  

Microsoft Academic Search

A comprehensive suite of brominated organic compounds was measured from whole air samples collected during the 1996 NASA Stratospheric Tracers of Atmospheric Transport aircraft campaign and the 1996 NASA Global Tropospheric Experiment Pacific Exploratory Mission-Tropics aircraft campaign. Measurements of individual species and total organic bromine were utilized to describe latitudinal and vertical distributions in the troposphere and lower stratosphere, fractional

S. M. Schauffler; E. L. Atlas; D. R. Blake; F. Flocke; R. A. Lueb; J. M. Lee-Taylor; V. Stroud; W. Travnicek

1999-01-01

419

The search for organic substances and inorganic volatile compounds in the surface of Mars  

Microsoft Academic Search

A total of four Martian samples, one surface and one subsurface sample at each of the two Viking landing sites, Chryse Planitia and Utopia Planitia, have been analyzed for organic compounds by a gas chromatograph-mass spectrometer. In none of these experiments could organic material of Martian origin be detected at detection limits generally of the order of parts per billion

K. Biemann; J. Oro; P. Toulmin III; L. E. Orgel; A. O. Nier; D. M. Anderson; D. Flory; A. V. Diaz; D. R. Rushneck; P. G. Simmonds; J. E. Biller; A. L. Lafleur

1977-01-01

420

EXPERIMENTAL DEVELOPMENT OF THE MASTER ANALYTICAL SCHEME FOR ORGANIC COMPOUNDS IN WATER: PART 1. TEXT  

EPA Science Inventory

The Master Analytical Scheme (MAS) for Organic Compounds in Water provides for analysis of purgeable and extractable, as well as neutral and ionic-water-soluble, organics in surface and drinking water and in leachates and various effluents. This report describes experiments in th...

421

EXPERIMENTAL DEVELOPMENT OF THE MASTER ANALYTICAL SCHEME FOR ORGANIC COMPOUNDS IN WATER: PART 2. APPENDICES  

EPA Science Inventory

The Master Analytical Scheme (MAS) for Organic Compounds in Water provides for analysis of purgeable and extractable, as well as neutral and ionic-water-soluble, organics in surface and drinking water and in leachates and various effluents. This report describes experiments in th...

422

Interaction of organic compounds with calcium carbonate--I. Association phenomena and geochemical implications  

Microsoft Academic Search

Stearic acid and albumin dissolved in distilled water, as well as lipoid and amino acid-containing substances dissolved in seawater, interact with carbonate mineral surfaces. In seawater, these compounds represent 14 per cent of the total dissolved organic carbon which is removed from solution by adsorption processes onto carbonate minerals. The mineral surfaces are saturated with organic carbon after adsorbing 0.1

Erwin Suess

1970-01-01

423

Supporting Information1 Condensational Uptake of Semivolatile Organic Compounds in Gasoline3  

E-print Network

emissions processing33 system. Total gasoline exhaust organic vapour was treated as an additional gas the individual species rate coefficients43 in the VOC emissions profile for gasoline exhaust.44 Gasoline exhaustSupporting Information1 2 Condensational Uptake of Semivolatile Organic Compounds in Gasoline3

Meskhidze, Nicholas

424

Hazardous organic compounds in biogas plant end products--soil burden and risk to food safety.  

PubMed

The end products (digestate, solid fraction of the digestate, liquid fraction of the digestate) of ten biogas production lines in Finland were analyzed for ten hazardous organic compounds or compound groups: polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCB(7)), polyaromatic hydrocarbons (PAH(16)), bis-(2-ethylhexyl) phthalate (DEHP), perfluorinated alkyl compounds (PFCs), linear alkylbenzene sulfonates (LASs), nonylphenols and nonylphenol ethoxylates (NP+NPEOs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA). Biogas plant feedstocks were divided into six groups: municipal sewage sludge, municipal biowaste, fat, food industry by-products, animal manure and others (consisting of milling by-products (husk) and raw former foodstuffs of animal origin from the retail trade). There was no clear connection between the origin of the feedstocks of a plant and the concentrations of hazardous organic compounds in the digestate. For PCDD/Fs and for DEHP, the median soil burden of the compound after a single addition of digestate was similar to the annual atmospheric deposition of the compound or compound group in Finland or other Nordic countries. For PFCs, the median soil burden was somewhat lower than the atmospheric deposition in Finland or Sweden. For NP+NPEOs, the soil burden was somewhat higher than the atmospheric deposition in Denmark. The median soil burden of PBDEs was 400 to 1000 times higher than the PBDE air deposition in Finland or in Sweden. With PBDEs, PFCs and HBCD, the impact of the use of end products should be a focus of further research. Highly persistent compounds, such as PBDE- and PFC-compounds may accumulate in agricultural soil after repeated use of organic fertilizers containing these compounds. For other compounds included in this study, agricultural use of biogas plant end products is unlikely to cause risk to food safety in Finland. PMID:24593894

Suominen, K; Verta, M; Marttinen, S

2014-09-01

425

Hot-atom synthesis of organic compounds on Jupiter  

NASA Technical Reports Server (NTRS)

Results of recent laboratory 'simulations' of photochemical processes on Jupiter are combined with available data on mixing rates and exposure times in the Jovian atmosphere to give quantitative predictions of the rate at which hot-atom reactions produce organic molecules. It is shown that abstraction reactions on methane by hot H atoms from solar UV photolysis of H2S will produce no more than 4 times 10 to the -17th power g/sq cm/sec for a steady-state mole fraction of total organics of approximately 10 to the -16th power. This is roughly 10 to the 7th power times less than the limit of detection of the most sensitive gas analysis experiments ever flown on a spacecraft. By far the most common organic molecule produced by this mechanism is CH3SH, methyl mercaptan, which is produced at a rate at least 600 times smaller than the rate of production of ethane by direct photolysis of CH4 at high altitudes.

Lewis, J. S.; Fegley, B., Jr.

1979-01-01

426

Organic chemistry of basal ice - presence of labile, low molecular weight compounds available for microbial metabolism  

NASA Astrophysics Data System (ADS)

Recent studies show that subglacial environments previously thought to be devoid of life contain a host of active microbial organisms. Presence of liquid water due to overburden pressure, the release of nutrients from chemical erosion of bedrock, and the potential carbon sources in overridden sediments facilitate life in this extreme environment. However, little is still known of concentrations and diversity of labile organic compounds essential for sustaining microbial metabolism in subglacial environments. Three subglacial ecosystems that considerably differ in range and amount of available organic compounds were selected for this study 1-Engabreen, northern Norway, overlying high-grade metamorphic rocks with low organic carbon content; 2-Finsterwalderbreen, Svalbard, overriding ancient black shales with a relatively high carbon content yet recalcitrant to microbiological consumption; and 3-Russell Glacier in western Greenland with recently overridden quaternary organic rich paleosols. Basal and pressure ridge ice samples were collected and subsequently analysed for low molecular weight organic compounds, with the emphasis on volatile fatty acids, carbohydrates and amino acids. The highest concentration of labile organic compounds in Greenland basal ice suggest that recently overridden paleosols have the greatest potential for sustaining microbial populations present within and underneath basal ice. The high concentration of "ancient" organic carbon in basal ice from Finsterwalderbreen, Svalbard, doesn't correlate with the presence of labile organic compounds. This indicates the inability of microbes to digest recalcitrant kerogen carbon in cold temperatures. In all three investigated environments, concentrations of labile organic compounds are elevated in basal ice with a high debris content. Until recently, most models of the global carbon cycle tend to neglect the pool of subglacial organic carbon as little is known about the range and concentrations of organic compounds as well as the composition of microbial communities and their ability to degrade and metabolize organic carbon at low temperatures. Recently overridden paleosols in western Greenland may serve as a biogeochemical model for vast pool of organic carbon from areas of boreal forest and tundra overridden during the Quaternary glacial cycles.

Lis, Grzegorz P.; Wadham, Jemma L.; Lawson, Emily; Stibal, Marek; Telling, Jon

2010-05-01

427

Screening processed milk for volatile organic compounds using vacuum distillation/gas chromatography/mass spectrometry.  

PubMed

An adaptation is presented of method 8261--from the Office of Solid Waste and Emergency Response Test Methods for Evaluating Solid Waste Physical/Chemical Methods (SW-846)-to analyze milk for an expanded list of volatile organic compounds is presented. The milk matrix exhibits a strong affinity for organic compounds and the surrogate based matrix normalization described in method 8261 provided accurate results. This method had the sensitivity necessary to detect volatile organic analytes at or below maximum contaminant levels (MCLs) set by EPA for drinking water. In a survey of milk samples available in Las Vegas, Nevada, 32 of 88 targeted volatile organic compounds (VOCs) were detected. Many of the detected VOCs have not previously been reported and a rationale for their presence in milk is presented. PMID:15106669

Hiatt, M H; Pia, J H

2004-02-01

428

Measurements of Organic Bromine Compounds in the UT/LS region  

NASA Astrophysics Data System (ADS)

The transport of short lived reactive organic compounds from surface sources to the upper troposphere can have an impact on the chemistry of the tropopause region. In particular, there has been recent interest on the possible role of bromine on the chemistry of ozone loss in the lower stratosphere. Measurements of organic bromine gases have been made during recent studies in the tropical and mid-latitude UT/LS region. Samples collected from the NASA WB-57F aircraft during AVE missions were analyzed for a large suite of organic bromine gases that define the organic bromine budget of the UT/LS region. The compounds include the longer-lived methyl bromide and halons, and a range of shorter-lived brominated organic gases. The distribution, vertical structure, and variability of organic bromine species in the tropical upper troposphere will be presented here.

Atlas, E.; Lueb, R.; Zhu, X.; Custals, L.; Tremblay, R.

2006-12-01

429

Factors affecting bioabsorption, metabolism, and storage of organic compounds by aquatic biota  

SciTech Connect

Biological concentration and transfer of organic chemicals through aquatic food webs can be influenced by a variety of environmental, biological, and biochemical factors. Bioaccumulation can be significantly altered by the presence of suspended matter or complex organic mixtures in the water column. In addition, the bioaccumulation factor of a compound is dependent on the species of an organism, its life stage, and the available food supply. Metabolic changes in structure of absorbed organics can alter both the rate and the mechanism of absorption and elimination of organics. In the case of quinoline absorption by trout, both the rate of absorption and the metabolic disposition depended upon whether exposure was through ingestion or through direct water column exposure. All of these factors can be used to explain why the physical properties of organic compounds (most notably octanol/water partition coefficients) are unreliable predictors of bioaccumulation potential. 24 refs., 1 tab.

Bean, R.M.; Dauble, D.D.; Thomas, B.L.; Hanf, R.W.; Chess, E.K.

1985-12-01

430

Volatile organic compounds in the air of Izmir, Turkey  

NASA Astrophysics Data System (ADS)

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.

Muezzinoglu, Aysen; Odabasi, Mustafa; Onat, Levent

431

Analysis of 34S in Individual Organic Compounds by Coupled GC-ICP-MS  

Microsoft Academic Search

The abundances of 2H, 13C, and 15N in organic compounds have been extremely useful in many aspects of biogeochemistry. While sulfur plays an equally important role in many earth-surface processes, the isotopes of sulfur in organic matter have not been extensively employed in large part because there has been no direct route to the analysis of 34S in individual organic

A. L. Sessions; A. Amrani; J. F. Adkins

2009-01-01

432

In silico estimation of DMSO solubility of organic compounds for bioscreening.  

PubMed

Solubility of organic compounds in DMSO is an important issue for commercial and academic organizations handling large compound collections or performing biological screening. In particular, solubility data are critical for the optimization of storage conditions and for the selection of compounds for bioscreening compatible with the assay protocol. Solubility is largely determined by the solvation energy and the crystal disruption energy, and these molecular phenomena should be assessed in structure-solubility correlation studies. The authors summarize our long-term experimental observations and theoretical studies of physicochemical determinants of DMSO solubility of organic substances. They compiled a comprehensive reference database of proprietary data on compound solubility (55,277 compounds with good DMSO solubility and 10,223 compounds with poor DMSO solubility), calculated specific molecular descriptors (topological, electromagnetic, charge, and lipophilicity parameters), and applied an advanced machine-learning approach for training neural networks to address the solubility. Both supervised (feed-forward, back-propagated neural networks) and unsupervised (Kohonen neural networks) learning methods were used. The resulting neural network models were validated by successfully predicting DMSO solubility of compounds in independent test selections. PMID:15006145

Balakin, Konstantin V; Ivanenkov, Yan A; Skorenko, Andrey V; Nikolsky, Yuri V; Savchuk, Nikolay P; Ivashchenko, Andrey A

2004-02-01

433

Partitioning of Organic Contaminants and Tracer Compounds in a CO2-Brine System at High Salinities  

NASA Astrophysics Data System (ADS)

Nonionic chemical species including gases and organic compounds partition between the fluid CO2 phase and the aqueous phase in geologic carbon sequestration systems. The injection and migration of CO2 in geologic carbon sequestration systems covers a wide range of pressure and temperature, so it is important to understand the partitioning of these compounds at various P-T conditions and salinities. Geochemical data is particularly lacking for the partitioning of organic contaminant compounds and tracer compounds between highly saline brines and CO2. Most groundwater is relatively low in organic contaminants; however, groundwater associated with hydrocarbon migration pathways, enhanced oil recovery (EOR), and hydrocarbon storage or extraction can contain high concentrations of known organic contaminants. CO2 injection in these systems may therefore be more likely to result in partitioning of contaminants into the CO2 phase that could, upon migration, represent an important risk to groundwater resources. We present the experimental apparatus and determination of partition coefficients between brine and CO2 for a suite of compounds including benzene, toluene, ethylbenzene, xylene (BTEX), and low molecular weight polynuclear aromatic hydrocarbons (PAHs). In addition, partition coefficients are determined for the important gas phase tracer compounds: SF6 and Krypton covering a P-T envelope consistent with CO2 injection and plume migration to the near surface.

Thomas, B.; Kharaka, Y. K.; Rosenbauer, R. J.; Janesko, D.; Trutna, J.

2011-12-01

434

Composites for removing metals and volatile organic compounds and method thereof  

DOEpatents

Functionalized hydrophobic aerogel/solid support structure composites have been developed to remove metals and organic compounds from aqueous and vapor media. The targeted metals and organics are removed by passing the aqueous or vapor phase through the composite which can be in molded, granular, or powder form. The composites adsorb the metals and the organics leaving a purified aqueous or vapor stream. The species-specific adsorption occurs through specific functionalization of the aerogels tailored towards specific metals and/or organics. After adsorption, the composites can be disposed of or the targeted metals and/or organics can be reclaimed or removed and the composites recycled.

Coronado, Paul R. (Livermore, CA); Coleman, Sabre J. (Oakland, CA); Reynolds, John G. (San Ramon, CA)

2006-12-12

435

Comparing removal of trace organic compounds and assimilable organic carbon (AOC) at advanced and traditional water treatment plants  

Microsoft Academic Search

Stability of drinking water can be indicated by the assimilable organic carbon (AOC). This AOC value represents the regrowth\\u000a capacity of microorganisms and has large impacts on the quality of drinking water in a distribution system. With respect to\\u000a the effectiveness of traditional and advanced processing methods in removing trace organic compounds (including TOC, DOC,\\u000a UV254, and AOC) from water,

Jie-Chung Lou; Chung-Yi Lin; Jia-Yun Han; Wei-Biu Tseng; Kai-Lin Hsu; Ting-Wei Chang

436

Partitioning of Semivolatile Organic Compounds in the Presence of a Secondary Organic Aerosol in a Controlled Atmosphere  

Microsoft Academic Search

The gas-particle partitioning of select semivolatile organic compounds (SOCs) was studied by injecting the SOCs into a 190 m3 Teflon film chamber containing a secondary organic aerosol (SOA) generated by volatilizing liquid a-pinene into an ozone-concentrated atmosphere. The concentration of total suspended particulates (TSP) and gas and particle-phase SOCs was measured over the course of three experiments spanning a temperature

Keri B. Leach; Richard M. Kamens; Michael R. Strommen; Myoseon Jang

1999-01-01

437

Source profiles of organic compounds emitted upon combustion of green vegetation from temperate climate forests.  

PubMed

Biomass burning is an important primary source of particles containing biomarker compounds, which are introduced into smoke primarily by direct volatilization/steam stripping and by thermal alteration based on combustion conditions. This study presents comprehensive organic compound source profiles for smoke from controlled burning of green vegetation native to the predominant temperate and semiarid forests of the western United States. Smoke particles were extracted with dichloromethane/methanol (2:1, v/v), and the extracts were analyzed as their TMS derivatives by gas chromatography-mass spectrometry. Carbohydrates were by far the major compound class emitted in smoke particles, encompassing 57-77% of the total extractable organic compounds detected here. Lignin derivatives (5-17%) and diterpenoids (up to 16%) from bleed resins were the next most abundant compound groups observed. The major individual compounds encompassed methyl-inositols (up to 41%, e.g., pinitol) for conifer smokes, deoxy-inositols (up to 32%, e.g., quercitol) for samples containing oak vegetation, and the thermally altered product of cellulose combustion levoglucosan (14-21%). The remaining compound classes, i.e., n-alkanoic acids, n-alkanols, n-alkanes, triterpenoids, steroids, and polycyclic aromatic hydrocarbons, were present at lower abundances (mostly < 5%). The results showed that burning of green (moist) vegetation imprints high amounts of polar/ water-soluble compounds into the smoke probably by volatilization/steam stripping processes, resulting in a different biomarker profile compared to dry/dead vegetation and wood combustion emissions. PMID:19068811

Medeiros, Patricia M; Simoneit, Bernd R T

2008-11-15

438

Responses of polar organic compounds to different ionic environments in aqueous media are interrelated.  

PubMed

Solubilities of 17 polar organic compounds in aqueous solutions of Na2SO4, NaCl, NaClO4, and NaSCN at the salt concentrations of up to 1.0-2.0 M were determined and the Setschenow constant, ksalt, values were estimated. It was found that NaClO4 may display both salting-in and salting-out effects depending on the particular compound structure. The Setschenow constant values for all the polar compounds examined in different salt solutions are found to be interrelated. Similar relationships were observed for partition coefficients of nonionic organic compounds in aqueous polyethylene glycol-sodium sulfate two-phase systems in the presence of different salt additives reported previously [Ferreira et al., J. Chromatogr. A, 2011, 1218, 5031], and for the effects of different salts on optical rotation of amino acids reported by Rossi et al. [J. Phys. Chem. B, 2007, 111, 10510]. In order to explain the observed relationships it is suggested that all the effects observed originate as responses of the compounds to the presence of a given ionic environment and its interaction with the compounds by forming direct or solvent-separated ionic pairs. The response is compound-specific and its strength is determined by the compound structure and the type (and concentration) of ions inducing the response. PMID:25260049

Ferreira, L A; Chervenak, A; Placko, S; Kestranek, A; Madeira, P P; Zaslavsky, B Y

2014-11-14

439

Measurements of chlorinated volatile organic compounds emitted from office printers and photocopiers.  

PubMed

Office devices can release volatile organic compounds (VOCs) partly generated by toners and inks, as well as particles of paper. The aim of the presented study is to identify indoor emissions of volatile halogenated organic compounds into the office workspace environment. Mixtures of organic pollutants emitted by seven office devices, i.e. printers and copiers, were analyzed by taking samples in laboratory conditions during the operation of these appliances. Tests of volatile organic compound emissions from selected office devices were conducted in a simulated environment (test chamber). Samples of VOCs were collected using three-layered thermal desorption tubes. Separation and identification of organic pollutant emissions were made using thermal desorption combined with gas chromatography coupled to mass spectrometry. Test chamber studies indicated that operation of the office printer and copier would contribute to the significant concentration level of VOCs in typical office indoor air. Among the determined volatile halogenated compounds, only chlorinated organic compounds were identified, inter alia: trichloroethylene - carcinogenic - and tetrachloroethylene - possibly carcinogenic to human. The results show that daily exposure of an office worker to chemical factors released by the tested printing and copying units can be variable in terms of concentrations of VOCs. The highest emissions in the test chamber during printing were measured for ethylbenzene up to 41.3 ?g m(-3), xylenes up to 40.5 ?g m(-3) and in case of halogenated compounds the highest concentration for chlorobenzene was 6.48 ?g m(-3). The study included the comparison of chamber concentrations and unit-specific emission rates of selected VOCs and the identified halogenated compounds. The highest amount of total VOCs was emitted while copying with device D and was rated above 1235 ?g m(-3) and 8400 ?g unit(-1) h(-1) on average. PMID:25323406

Kowalska, Joanna; Szewczy?ska, Ma?gorzata; Po?niak, Ma?gorzata

2015-04-01

440

Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments  

SciTech Connect

There is considerable interest in the ``unattached`` fraction of radon progeny in indoor air because of its significance to the estimation of the risks of radon exposure. Because of its high mobility in air, the unattached fraction is more efficiently deposited in the respiratory tract. Variation in the diameter of the ``unattached`` fraction and in its diffusion coefficient can be due to clustering of other atmospheric species around the {sup 218}PoO{sub 2}{sup +} ion. The purpose of this study was to investigate the potential for the formation of clusters of vapor phase organic compounds, found in indoor air, around the {sup 218}PoO{sub 2}{sup +} ion and to determine which were most likely to form clusters. A secondary purpose was to provide a compilation of measurements of indoor organic compounds for future experiments and theoretical calculations by the radon research community. The classical charged liquid droplet theory (Thomson equation) was used to estimate the Gibbs free energy of ion-induced nucleation and to provide an indication of the indoor organic compounds most likely to undergo ion-induced nucleation. Forty-four volatile and semi-volatile organic compounds out of the more than 300 which have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the {sup 218}PoO{sub 2}{sup +} ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones and the acetates) and the semi-volatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos).

Daisey, J.M.

1991-11-01

441

Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments  

SciTech Connect

There is considerable interest in the unattached'' fraction of radon progeny in indoor air because of its significance to the estimation of the risks of radon exposure. Because of its high mobility in air, the unattached fraction is more efficiently deposited in the respiratory tract. Variation in the diameter of the unattached'' fraction and in its diffusion coefficient can be due to clustering of other atmospheric species around the {sup 218}PoO{sub 2}{sup +} ion. The purpose of this study was to investigate the potential for the formation of clusters of vapor phase organic compounds, found in indoor air, around the {sup 218}PoO{sub 2}{sup +} ion and to determine which were most likely to form clusters. A secondary purpose was to provide a compilation of measurements of indoor organic compounds for future experiments and theoretical calculations by the radon research community. The classical charged liquid droplet theory (Thomson equation) was used to estimate the Gibbs free energy of ion-induced nucleation and to provide an indication of the indoor organic compounds most likely to undergo ion-induced nucleation. Forty-four volatile and semi-volatile organic compounds out of the more than 300 which have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the {sup 218}PoO{sub 2}{sup +} ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones and the acetates) and the semi-volatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos).

Daisey, J.M.

1991-11-01

442

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

SciTech Connect

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)

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

2013-07-01

443

Organic compounds in the Forest Vale, H4 ordinary chondrite  

NASA Astrophysics Data System (ADS)

We have analyzed the H4 ordinary chondrite Forest Vale for polycyclic aromatic hydrocarbons (PAHs) using two-step laser mass spectrometry (L 2MS) and for amino acids using a standard Chromatographic method. Indigenous PAHs were identified in the matrices of freshly cleaved interior faces but could not be detected in pulverized silicates and chondrules. No depth dependence of the PAHs was found in a chipped interior piece. Amino acids, taken from the entire sample, consisted of protein amino acids that were nonracemic, indicating that they are terrestrial contaminants. The presence of indigenous PAHs and absence of indigenous amino acids provides support for the contention that different processes and environments contributed to the synthesis of the organic matter in the solar system.

Zenobi, Renato; Philippoz, Jean-Michel; Zare, Richard N.; Wing, Michael R.; Bada, Jeffrey L.; Marti, Kurt

1992-07-01

444

Compound specific 13C- and 18O-isotope analysis of organic aerosols  

NASA Astrophysics Data System (ADS)

The wide ranging environmental and health effects of aerosols are increasingly coming to light. Various studies have further highlighted the complex nature of organic aerosols, particularly oxidised organics with multiple functional groups. Source apportionment studies on aerosols are crucial to successful implementation of mitigation strategies, but this is complicated by their complex nature. Ideally, individual components of aerosols can be tracked from their source to their atmospheric sink. However, chemical alteration and the formation of secondary aerosols in the atmosphere often preclude this direct tracking on a compound specific basis. Compound specific isotope analysis could overcome these problems, as certain processes and sources impose characteristic isotope ratios on products, which may be retained even after chemical alteration in the atmosphere. Progress has been made over the past decades in the separation and identification of individual compounds that contribute to aerosol formation. Compound separation by gas chromatography (GC), coupled to mass spectrometry (MS), has enabled identification of organic compounds of various sources. On the other hand, only few studies have addressed the isotopic composition of these compounds. For successful isotopic analysis of specific compounds, using GC coupled to isotope ratio MS (GC-irMS), several challenges must be faced that go beyond the requirements for GC-MS-based compound identification. Sample extraction and handling techniques must avoid isotope fractionation. This is especially important in the light of sample extraction by e.g. thermal desorption, which may impose a temperature-induced fractionation on complex organics. Furthermore, derivatisation techniques, necessary for adequate GC compound separation, must not lead to exchange reactions of the element of interest, which would alter the measured isotope ratio. So far most studies have dealt with carbon, and other elements have been neglected. Elements other than carbon may provide valuable additional information. Here we report on the development of methods for the analysis of stable carbon and oxygen isotope ratios of organic compounds in aerosols, through GC-combustion-irMS and GC-pyrolysis-irMS. We apply these analyses to environmental aerosol samples and samples of smog-chamber experiments, with the aim of identifying isotopic signatures of sources and pathways. We will pay special attention to derivatisation techniques - notably alternatives to the often-used trimethylsilyl derivatives in GC-pyrolysis-irMS for ?18O analysis - and to compound separation and identification. We present initial data of combined ?13C and ?18O studies on (secondary) organic aerosol samples, and their added value for source apportionment studies.

Blees, Jan; Saurer, Matthias; Siegwolf, Rolf T. W.; Dommen, Josef; Baltensperger, Urs

2014-05-01

445

Gas chromatographic--mass spectrometric determination of volatile organic compounds in fish.  

PubMed

A technique has been developed for the determination of volatile organic compounds in fish. The methodology is based on procedures used to determine purgeable organic compounds in water and wastewater. Fish tissue is added to reagent water, cooled in an ice bath, and homogenized with cell disruption using ultrasonic energy. The processed sample is then analyzed by a purge and trap procedure using an impinger-type device at 70 degrees C, with determination of the purged compounds by computerized gas chromatography-mass spectrometry. Both ground fish and cored fish specimens were successfully analyzed by this technique. The overall average recovery for 39 volatile compounds studied was 77% with an average standard deviation of 20%. PMID:7240070

Easley, D M; Kleopfer, R D; Carasea, A M

1981-05-01

446

Photosynthesis of organic compounds in the atmosphere of Jupiter  

NASA Technical Reports Server (NTRS)

An efficient conversion of CH4 to hydrocarbons and HCN takes place when NH3 is photolysed in the presence of CH4, H2, and He using a 184.9 nm light source. The extent of NH3 decomposition after a 1 hr exposure was determined spectrophotometrically; CH4, N2, and C2 and C3 hydrocarbons were detected and analyzed by mass spectrometry. Photolysis of one molar equivalent of NH3 results in the loss of 0.84 molar equivalent of CH4, which apparently reacts with hot hydrogen atoms produced by photolysis. The 8% of the NH3 which is not converted to N2 probably is converted to organic amines and nitrile derivatives. The results indicate that NH3 photolysis is a highly probable mechanism for the conversion of methane to more complex hydrocarbons in the upper atmosphere of Jupiter, and predict the occurrence of HCN, NH2NH2, and higher hydrocarbons in the Jovian atmosphere above the NH3 clouds.

Ferris, J. P.; Chen, C. T.

1975-01-01

447

Development of technology performance specifications for volatile organic compounds  

SciTech Connect

The Office of Technology Development (OTD) within the Office of Environmental Restoration and Waste Management of the Department of Energy has a mission to deliver needed and usable technologies to its customers. The primary customers are individuals and organizations performing environmental characterization and remediation, waste cleanup, and pollution prevention at DOE sites. DOE faces a monumental task in cleaning up the dozen or so major sites and hundreds of smaller sites that were or are used to produce the US nuclear weapons arsenal and to develop nuclear technologies for national defense and for peaceful purposes. Contaminants and waste materials include the radionuclides associated with nuclear weapons, such as plutonium and tritium, and more common pollutants and wastes of industrial activity such as chromium, chlorinated solvents, and polychlorinated biphenyls (PCBs). Quite frequently hazardous wastes regulated by the Environmental Protection Agency are co-mingled with radioactive wastes regulated by the Nuclear Regulatory Commission to yield a {open_quotes}mixed waste,{close_quotes} which increases the cleanup challenges from several perspectives. To help OTD and its investigators meet DOE`s cleanup goal, technology performance specifications are being implemented for research and development and DT&E projects. Technology performance specifications or {open_quotes}performance goals{close_quotes} describe, quantitatively where possible, the technology development needs being addressed. These specifications are used to establish milestones, evaluate the status of ongoing projects, and determine the success of completed projects.

Purdy, C.; Schutte, W.E. [Dept. of Energy, Germantown, MD (US). Office of Environmental and Waste Management; Erickson, M.D.; Carpenter, S.C.; Doskey, P.V.; Lindahl, P.C.; Pflug, A.D. [Argonne National Lab., IL (US)

1993-07-01

448

Biodegradation of organic compounds in vadose zone and aquifer sediments.  

PubMed Central

The microbial processes that occur in the subsurface under a typical Midwest agricultural soil were studied. A 26-m bore was installed in November of 1988 at a site of the Purdue University Agronomy Research Center. Aseptic collections of soil materials were made at 17 different depths. Physical analysis indicated that the site contained up to 14 different strata. The site materials were primarily glacial tills with a high carbonate content. The N, P, and organic C contents of sediments tended to decrease with depth. Ambient water content was generally less than the water content, which corresponds to a -0.3-bar equivalent. No pesticides were detected in the samples, and degradation of added 14C-labeled pesticides (atrazine and metolachlor) was not detected in slurry incubations of up to 128 days. The sorption of atrazine and metolachlor was correlated with the clay content of the sediments. Microbial biomass (determined by direct microscopic count, viable count, and phospholipid assay) in the tills was lower than in either the surface materials or the aquifer located at 25 m. The biodegradation of glucose and phenol occurred rapidly and without a lag in samples from the aquifer capillary fringe, saturated zone, and surface soils. In contrast, lag periods and smaller biodegradation rates were found in the till samples. Subsurface sediments are rich in microbial numbers and activity. The most active strata appear to be transmissive layers in the saturated zone. This implies that the availability of water may limit activity in the profile. PMID:1768098

Konopka, A; Turco, R

1991-01-01

449

Solute transport model for trace organic neutral and charged compounds through nanofiltration and reverse osmosis membranes.  

PubMed

Rejection of trace organic compounds, including disinfection by-products (DBPs) and pharmaceutical active compounds (PhACs), by high-pressure membranes has become a focus of public interest internationally in both drinking water treatment and wastewater reclamation/reuse. The ability to simulate, or even predict, the rejection of these compounds by high-pressure membranes, encompassing nanofiltration (NF) and reverse osmosis (RO), will improve process economics and expand membrane applications. The objective of this research is to develop a membrane transport model to account for diffusive and convective contributions to solute transport and rejection. After completion of cross-flow tests and diffusion cell tests with target compounds, modeling efforts were performed in accordance with a non-equilibrium thermodynamic transport equation. Comparing the percentages of convection and diffusion contributions to transport, convection is dominant for most compounds, but diffusion is important for more hydrophobic non-polar compounds. Convection is also more dominant for looser membranes (i.e., NF). In addition, higher initial compound concentrations and greater J(0)/k ratios contribute to solute fluxes more dominated by convection. Given the treatment objective of compound rejection, compound transport and rejection trends are inversely related. PMID:17631378

Kim, Tae-Uk; Drewes, Jörg E; Scott Summers, R; Amy, Gary L

2007-09-01

450

Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds  

USGS Publications Warehouse

Samples of water and sediment from a conventional drinking-water-treatment (DWT) plant were analyzed for 113 organic compounds (OCs) that included pharmaceuticals, detergent degradates, flame retardants and plasticizers, polycyclic aromatic hydrocarbons (PAHs), fragrances and flavorants, pesticides and an insect repellent, and plant and animal steroids. 45 of these compounds were detected in samples of source water and 34 were detected in samples of settled sludge and (or) filter-backwash sediments. The average percent removal of these compounds was calculated from their average concentration in time-composited water samples collected after clarification, disinfection (chlorination), and granular-activated-carbon (GAC) filtration. In general, GAC filtration accounted for 53% of the removal of these compounds from the aqueous phase; disinfection accounted for 32%, and clarification accounted for 15%. The effectiveness of these treatments varied widely within and among classes of compounds; some hydrophobic compounds were strongly oxidized by free chlorine, and some hydrophilic compounds were partly removed through adsorption processes. The detection of 21 of the compounds in 1 or more samples of finished water, and of 3 to 13 compounds in every finished-water sample, indicates substantial but incomplete degradation or removal of OCs through the conventional DWT process used at this plant. ?? 2007 Elsevier B.V. All rights reserved.

Stackelberg, P.E.; Gibs, J.; Furlong, E.T.; Meyer, M.T.; Zaugg, S.D.; Lippincott, R.L.

2007-01-01

451

Cost Analysis of Activated Carbon Versus Photocatalytic Oxidation for Removing Organic Compounds from Indoor Air  

Microsoft Academic Search

A cost comparison has been conducted of 1 m\\/sec indoor air cleaners using granular activated carbon (GAC) versus photocatalytic oxidation (PCO) for treating a steady-state inlet volatile organic compound (VOC) concentration of 0.27 mg\\/m. The commercial GAC unit was costed assuming that the inlet VOCs had a reasonable carbon sorption affinity, representative of compounds having four or more atoms (exclusive

D. Bruce Henschel

1998-01-01

452

Supercritical CO2 extraction of organic compounds from soil-water slurries  

E-print Network

in equipment acting similar to an HPLC which was interfaced with the extraction vessel. These experiments were conducted at three pressures at 298 K and 318 K for each contaminant. Experiments for all compounds revealed that percent extraction was nearly... independent of pressure at 298 K and was highly dependent on pressure at 318 K. Extraction varied with experimental conditions and the compound used but the maximum removal for each organic was at least 86%. For 2, 4-dichlorophenol, pentachlorophenol...

Carter, Brian Dean

1993-01-01

453

Microbial consumption and production of volatile organic compounds at the soil-litter interface  

Microsoft Academic Search

Substantial amounts of volatile organic compounds (VOCs) can be released during decomposition and these compounds can affect\\u000a atmospheric chemistry, belowground processes, and the structure of microbial communities in litter and soil. However, we have\\u000a a limited understanding of the types, quantities and ecological impacts of VOCs emitted from litter. Here we used a closed\\u000a flow-through system and proton transfer reaction

Kelly S. RamirezChristian; Christian L. Lauber; Noah Fierer

2010-01-01

454

Modelling uptake into roots and subsequent translocation of neutral and ionisable organic compounds  

Microsoft Academic Search

Abstract: A study,on,uptake,of neutral,and,dissociating,organic,compounds,from,soil solution,into roots, and their subsequent translocation, was undertaken using model simulations. The model approach combines the processes of lipophilic sorption, electrochemical interactions, ion trap, advection in xylem and dilution by growth. It needs as input data, apart from plant properties, log KOW, pKa and the valency number of the compound, and pH and chemical concentration in

Stefan Trapp

2000-01-01

455

Evaluation of persistent hydrophobic organic compounds in the Columbia River Basin using semipermeable-membrane devices  

Microsoft Academic Search

Persistent hydrophobic organic compounds are of concern in the Columbia River because they have been correlated with adverse effects on wildlife. We analysed samples from nine main-stem and six tributary sites throughout the Columbia River Basin (Washington and Oregon) for polychlorinated dibenzo-p-dioxins, dibenzofurans, polychlorinated biphenyls, organochlorine pesticides, and priority-pollutant polycyclic aromatic hydrocarbons. Because these compounds may have important biological consequences

Kathleen A. McCarthy; Robert W. Gale

2001-01-01

456

Mathematical modeling of atmospheric fine particle-associated primary organic compound concentrations  

NASA Astrophysics Data System (ADS)

An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped autos, diesel trucks, paved road dust, tire wear, brake lining dust, meat cooking operations, industrial oil-fired boilers, roofing tar pots, natural gas combustion in residential homes, cigarette smoke, fireplaces burning oak and pine wood, and plant leaf abrasion products. These primary fine particle source emissions were supplied to a computer-based model that simulates atmospheric transport, dispersion, and dry deposition based on the time series of hourly wind observations and mixing depths. Monthly average fine particle organic compound concentrations that would prevail if the primary organic aerosol were transported without chemical reaction were computed for more than 100 organic compounds within an 80 km × 80 km modeling area centered over Los Angeles. The monthly average compound concentrations predicted by the transport model were compared to atmospheric measurements made at monitoring sites within the study area during 1982. The predicted seasonal variation and absolute values of the concentrations of the more stable compounds are found to be in reasonable agreement with the ambient observations. While model predictions for the higher molecular weight polycyclic aromatic hydrocarbons (PAH) are in agreement with ambient observations, lower molecular weight PAH show much higher predicted than measured atmospheric concentrations in the particle phase, indicating atmospheric decay by chemical reactions or evaporation from the particle phase. The atmospheric concentrations of dicarboxylic acids and aromatic polycarboxylic acids greatly exceed the contributions that are due to direct emissions from primary sources, confirming that these compounds are principally formed by atmospheric chemical reactions.

Rogge, Wolfgang F.; Hildemann, Lynn M.; Mazurek, Monica A.; Cass, Glen R.; Simoneit, Bernd R. T.

1996-08-01

457

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

USGS Publications Warehouse

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

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

1985-01-01

458

Conductance of Conjugated Organic Compounds in Controlled Environments  

NASA Astrophysics Data System (ADS)

We use the mechanical and the electromigration break junction technique, as well as nanoparticle arrays, to measure the electrical conductance of a range of conjugated organic molecules with different end functionalities at room temperature in a liquid cell. We first report on a comparison between oligo(phenylene vinylene) (OPV) oligo(phenylene ethynylene) (OPE). We find that OPV conducts slightly better than OPE. Solubilizing side groups do not prevent the molecules from being anchored within a break junction. With the aim to realize a functional switch, we show preliminary electrical conductance studies of a newly synthesized cruciform molecule. Using the nanoparticle platform we further demon-strate light and electrochemical-induced conductance switching of photochromic and redox molecules. We further discuss OPV and OPE molecules with different end groups, including asymmetric ones. To our surprise, molecules having an anchor group only on one side also gave rise to a pronounced mo-lecular signal. We attribute this effect to the interaction between neighboring molecules in the junction likely induced by ?-? stacking. This remarkable property highlights the importance of intermolecu-lar interaction in molecular junctions, an often overlooked aspect. If time permits, a recent study on low- frequency fluctuations in molecular junctions will be mentioned as well. Collaborators are (alphabetic order): J. Agustsson, J. Brunner, M. Calame, T. Gonzalez, S. Grunder, V. Horhoiu, R. Huber, J. Liao, M. Mayor, M. Mangold, S. Oberholzer, M. Steinacher, S. Wu, Z.M. Wu, (all at the Swiss Nanoscience Institute at the Univ. of Basel) and M. R. Bryce (Durham University, UK).

Schonenberger, Christian

2009-03-01