Analysis of volatiles induced by oviposition of elm leaf beetle Xanthogaleruca luteola on Ulmus minor.

PubMed

Wegener, R; Schulz, S; Meiners, T; Hadwich, K; Hilker, M

2001-03-01

Egg deposition of the elm leaf beetle Xanthogaleruca luteola causes the emission of volatiles from its food plant, Ulmus minor. These volatiles are exploited by the egg parasitoid, Oomyzus gallerucae, to locate its host. In contrast to other tritrophic systems, the release of volatiles is not induced by feeding but by egg deposition. Previous investigations showed that the release is systemic and can be triggered by jasmonic acid. Comparison of headspace analysis revealed similarities in the blend of volatiles emitted following egg deposition and feeding. The mixture consists of more than 40 compounds; most of the substances are terpenoids. Leaves next to those carrying eggs emit fewer compounds. When treated with jasmonic acid, leaves emit a blend that consists almost exclusively of terpenoids. Dichloromethane extracts of leaves treated with jasmonic acid were also investigated. After separation of extracts of jasmonate induced elm leaves on silica, we obtained a fraction of terpenoid hydrocarbons that was attractive to the parasitoids. This indicates that jasmonic acid stimulates the production of terpenoid hydrocarbons that convey information of egg deposition to the parasitoid.

NEOS AB3000

EPA Pesticide Factsheets

Technical product bulletin: this hydrocarbon solvent based dispersant used in oil spill cleanups can be sprayed neat on the oil slick in atomized form. Effective with crude and residual heavy oil, and also at controlling volatile emissions.

Thermal alteration experiments on organic matter from recent marine sediments in relation to petroleum genesis

NASA Technical Reports Server (NTRS)

Ishiwatari, R.; Ishiwatari, M.; Rohrback, B. G.; Kaplan, I. R.

1977-01-01

Three fractions of organic matter: lipid (benzene:methanol-extractable), humic acid (alkali-extractable) and kerogen (residue) were extracted from a young marine sediment (Tanner Basin, offshore southern California) and heated for different times (5-116 hr) and temperatures (150-410 C). The volatile (gases) and liquid products, as well as residual material, were then analyzed. On a weight basis, the lipid fraction produced 58% of the total identified n-alkanes, the kerogen fraction 41%, and the humic acid less than 1%. The volatiles produced by heating the lipid and humic acid fractions were largely CO2 and water, whereas those produced from heated kerogen also included methane, hydrogen gas and small amounts of C2-C4 hydrocarbons. A mechanism for hydrocarbon production due to the thermal alteration of organic constituents of marine sediment is discussed.

The effect of deodorization on volatile compositions of fucoidan extracted from brown seaweed (Sargassum sp.)

NASA Astrophysics Data System (ADS)

Khalafu, Sharifah Habibah Syed; Mustapha, Wan Aida Wan; Lim, Seng Joe; Maskat, Mohamad Yusof

2016-11-01

Fucoidan is a biologically active polysaccharide that were made up of complex mixture of fucose, sulfate and uronic acid. This study was conducted to identify the volatile compositions of crude fucoidan and deodorized fucoidans extracted from brown seaweed Sargassum sp. (Fsar). The volatile compositions was also compared with a standard commercial fucoidan (Fysk). Fucoidan was extracted from Sargassum sp. originated in coastal area of Indonesia, by using a low pH acid extraction method. Approximately 20 mL of 1% freshly extracted fucoidan was then subjected to deodorization process by using three different method i.e., by treating it with 10 g activated carbon (Fac), 0.4 g ion exchange resin, Amberlite 67 (Fresin) and 2 mL of 1% calcium carbonate (FCaCO3) and incubated for 12 hrs before further analysis. Forty-six volatile compounds were successfully identified in all of the five samples by using Headspace-Solid Phase Microextraction (HS-SPME) and analysed by using Gas Chromatography Mass Spectrometer (GCMS). In Fsar, 72% of the total volatile constituents were identified as aromatic hydrocarbons, 23% hydrocarbons and 5% alcohols. In Fysk, all compounds detected are in group hydrocarbons. In Fsar, all of the compounds identified were classified as odor active compounds which had a contribution to unpleasant odor in fucoidan. After deodorization, 72% of aromatic hydrocarbons detected in Fsar were reported to be absent in all deodorized fucoidans. Both Fresin and FCaCO3 showed a reduction in peak area percentages of phenol, 2,4-bis (1,1-dimethylethyl)- from Fsar (1.30%) to 0.79 and 1.07% respectively. Meanwhile in Fac, no presence of phenol, 2,4-bis (1,1-dimethylethyl) was reported. These findings are essential to propel the advancement of research in deodorization technologies of marine products, especially fucoidans.

Using supercritical fluids to refine hydrocarbons

DOEpatents

Yarbro, Stephen Lee

2014-11-25

This is a method to reactively refine hydrocarbons, such as heavy oils with API gravities of less than 20.degree. and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure using a selected fluid at supercritical conditions. The reaction portion of the method delivers lighter weight, more volatile hydrocarbons to an attached contacting device that operates in mixed subcritical or supercritical modes. This separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques. This method produces valuable products with fewer processing steps, lower costs, increased worker safety due to less processing and handling, allow greater opportunity for new oil field development and subsequent positive economic impact, reduce related carbon dioxide, and wastes typical with conventional refineries.

Role of alcohol dehydrogenase activity and the acetaldehyde in ethanol- induced ethane and pentane production by isolated perfused rat liver.

PubMed Central

Müller, A; Sies, H

1982-01-01

The volatile hydrocarbons ethane and n-pentane are produced at increased rates by isolated perfused rat liver during the metabolism of acutely ethanol. The effect is half-maximal at 0.5 mM-ethanol, and its is not observed when inhibitors of alcohol dehydrogenase such as 4-methyl- or 4-propyl-pyrazole are also present. Propanol, another substrate for the dehydrogenase, is also active. Increased alkane production can be initiated by adding acetaldehyde in the presence of 4-methyl- or 4-propyl-pyrazole. An antioxidant, cyanidanol, suppresses the ethanol-induced alkane production. The data obtained with the isolated organ demonstrate that products known to arise from the peroxidation of polyunsaturated fatty acids are formed in the presence of ethanol and that the activity of alcohol dehydrogenase is required for the generation of the active radical species. The mere presence of ethanol, e.g. at binding sites of special form(s) of cytochrome P-450, it not sufficient to elicit an increased production of volatile hydrocarbons by rat liver. PMID:6751324

Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions

USGS Publications Warehouse

Lahvis, Matthew A.; Baehr, Arthur L.; Baker, Ronald J.

1999-01-01

Aerobic biodegradation and volatilization near the water table constitute a coupled pathway that contributes significantly to the natural attenuation of hydrocarbons at gasoline spill sites. Rates of hydrocarbon biodegradation and volatilization were quantified by analyzing vapor transport in the unsaturated zone at a gasoline spill site in Beaufort, South Carolina. Aerobic biodgradation rates decreased with distance above the water table, ranging from 0.20 to 1.5 g m−3 d−1 for toluene, from 0.24 to 0.38 g m−3 d−1for xylene, from 0.09 to 0.24 g m−3 d−1 for cyclohexene, from 0.05 to 0.22 g m−3 d−1 for ethylbenzene, and from 0.02 to 0.08 g m−3 d−1 for benzene. Rates were highest in the capillary zone, where 68% of the total hydrocarbon mass that volatilized from the water table was estimated to have been biodegraded. Hydrocarbons were nearly completely degraded within 1m above the water table. This large loss underscores the importance of aerobic biodradation in limiting the transport of hydrocarbon vapors in the unsaturated zone and implies that vapor‐plume migration to basements and other points of contact may only be significant if a source of free product is present. Furthermore, because transport of the hydrocarbon in the unsaturated zone can be limited relative to that of oxygen and carbon dioxide, soil‐gas surveys conducted at hydrocarbon‐spill sites would benefit by the inclusion of oxygen‐ and carbon‐dioxide‐gas concentration measurements. Aerobic degradation kinetics in the unsaturated zone were approximately first‐order. First‐order rate constants near the water table were highest for cyclohexene (0.21–0.65 d−1) and nearly equivalent for ethylbenzene (0.11–0.31 d−1), xylenes (0.10–0.31 d−1), toluene (0.09–0.30 d−1), and benzene (0.07–0.31 d−1). Hydrocarbon mass loss rates at the water table resulting from the coupled aerobic biodgradation and volatilization process were determined by extrapolating gas transport rates through the capillary zone. Mass loss rates from groundwater were highest for toluene (0.20–0.84 g m−2 d−1), followed by xylenes (0.12–0.69 g m−2 d−1), cyclohexene (0.05–0.15 g m−2 d−1), ethylbenzene (0.02–0.12 g m−2 d−1), and benzene (0.01–0.04 g m−2 d−1). These rates exceed predicted rates of solubilization to groundwater, demonstrating the effectiveness of aerobic biodgradation and volatilization as a combined natural attenuation pathway.

Carbon isotope composition of low molecular weight hydrocarbons and monocarboxylic acids from Murchison meteorite

NASA Technical Reports Server (NTRS)

Yuen, G.; Blair, N.; Des Marais, D. J.; Chang, S.

1984-01-01

Carbon isotopic compositions have been measured for individual hydrocarbons and monocarboxylic acids from the Murchison meteorite, a C2 carbonaceous chondrite which fell in Australia in 1969. With few exceptions, notably benzene, the volatile products are substantially isotopically heavier than their terrestrial counterparts, signifying their extraterrestrial origin. For both classes of compounds, the ratio of C-13 to C-12 decreases with increasing carbon number in a roughly parallel manner, and each carboxylic acid exhibits a higher isotopic ratio than the hydrocarbon containing the same number of carbon atoms. These trends are consistent with the kinetically controlled synthesis of higher homologues from lower ones. The results suggest the possibility that the production mechanisms for hydrocarbons and carboxylic acids may be similar, and impose constraints on the identity of the reactant species.

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

PubMed Central

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

2014-01-01

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

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

PubMed

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

2014-01-01

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

Parametric study of two-stage hydropyrolysis of lignocellulosic biomass for production of gaseous and light aromatic hydrocarbons.

PubMed

Zheng, Nan; Zhang, Jie; Wang, Jie

2017-11-01

Non-catalytic hydropyrolysis of pinewood and its components was carried out using a two-stage reactor. The main aim of this work is to investigate the hydrodeoxygenation and hydrogenation of volatile matter in the post hydrocracking reactor for oriented production of gaseous and light aromatic hydrocarbons. A portion of volatile matter, which evolved from hemicellulose, neutral extractives and lignin below 275°C, was found to be thoroughly hydrodeoxygenated preventing the release of CO 2 and CO. Increasing hydrocracking temperature from 600°C to 750°C and pressure from 1.0MPa to 5.0MPa strongly facilitated the hydrogenation reactions to target products. The summed yield of CH 4 and C 2 H 6 (dry biomass basis) reached up to 33.2% at a hydrocracking temperature of 750°C and 5.0MPa, with a concomitant 5.1% yield of BTX. All components in pinewood significantly contributed to the production of CH 4 and BTX by hydropyrolysis, differing from the case of pyrolysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Volatile hydrocarbon profile of Iberian dry-cured hams. A possible tool for authentication of hams according to the fattening diet.

PubMed

Narváez-Rivas, Mónica; Vicario, Isabel M; Alcalde, M Jesús; León-Camacho, Manuel

2010-06-15

The aims of this work were to carry out a comprehensive study of the volatile hydrocarbons of 34 Iberian dry-cured hams and to evaluate the efficiency of these compounds for discriminating hams according to the fattening system: "Montanera" (B) and "Cebo" (C). The samples of hams were obtained by mincing the semimembranosus and semitendinosus muscles from slices of dry-cured ham. The analyses were carried out by gas chromatography-mass spectrometry with a polar capillary column and after a previous extraction by Purge and Trap method. Forty-three volatile hydrocarbons were identified, 26 of them for the first time in Iberian dry-cured ham. Only five compounds showed significant differences between the two types of hams. Among the 33 volatile hydrocarbons, 22 of them allowed a complete discrimination of the two groups of hams according the fattening system.

Potential chemical markers for the identification of irradiated sausages.

PubMed

Kwon, Joong Ho; Akram, Kashif; Nam, Ki Chang; Min, Byungrok; Lee, Eun Joo; Ahn, Dong U

2012-09-01

Hydrocarbons, gas compounds, and off-odor volatiles were determined for irradiated (0 or 5 kGy) commercial sausages with different fat contents (16% and 29%) during a 60-d storage period at 4 °C. Total of 4 hydrocarbons (C14:1, C15:0, C16:2, and C17:1) were detected only in irradiated sausages: the amount of C16:2 was the highest, followed by C17:1, C14:1, and C15:0. The concentrations of hydrocarbons decreased significantly (P < 0.05) with storage, but were still detectable at the end of 60-d storage. Irradiated sausages produced significantly higher amounts of CO than the nonirradiated ones. CH(4) was detected only in irradiated sausages. Dimethyl disulfide was detected only in irradiated sausages and its concentration decreased significantly (P < 0.05) with storage. Fat content of sausages showed a significant effect on the production and retention of hydrocarbons, gas compounds, and sulfur volatiles in irradiated sausages during storage. Some hydrocarbons (C16:2, C17:1, C14:1, and C15:0), CH(4) , and dimethyl disulfide were only found in irradiated sausages indicating that these compounds can be used as potential markers for irradiated sausages. © 2012 Institute of Food Technologists®

Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

EPA Science Inventory

Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are not. Thus, we examined the mutagenicity in Salmonella TA100 of photochemical atmospheres generated in a steady-state a...

Hydrothermal processing of biomass from invasive aquatic plants

Treesearch

W. James Catallo; Todd F. Shupe; Thomas L. Eberhardt

2008-01-01

The purpose of this study was to examine the hydrothermal (HT) treatment of three invasive aquatic plants (i.e., Lemna sp., Hydrilla sp., and Eichhornia sp.) with respect to the generation of semi-volatile hydrocarbon product mixtures and biomass volume reduction. Identical HT treatments yielded similar semi-...

Characterization by volatile compounds of microbial deep spoilage in Iberian dry-cured ham.

PubMed

Martín, Alberto; Benito, María J; Aranda, Emilio; Ruiz-Moyano, Santiago; Córdoba, Juan J; Córdoba, María G

2010-08-01

In the present study, volatile compounds of spoiled dry-cured Iberian ham with deep spoilage or "bone taint" were analyzed and correlated with level of spoilage and the microorganisms detected. Volatile compounds extracted by a solid phase micro-extraction technique were assayed by gas chromatography/mass spectrometry. The spoiled hams were evaluated sensorially, and the correlations among volatile compounds, spoilage level, and microbial counts were studied. The spoiled hams had higher concentrations of hydrocarbons, alcohols, acids, esters, pyrazines, sulfur compounds, and other minor volatile compounds than unspoiled hams. The sensorial analysis showed that the spoilage level of hams correlated with several volatile compounds, most of them associated with Gram-positive catalase positive cocci and Enterobacteriaceae counts. Cyclic compounds such as cyclohexanone, some ethers, and pyrazines should be considered as indicators to monitor incipient microbial deep spoilage in the elaboration of this meat product.

Palatability of sous vide processed chicken breast.

PubMed

Turner, B E; Larick, D K

1996-08-01

The influences of brine composition, internal temperature, heating rate, and storage periods up to 28 d on flavor, texture, and color of sous vide processed chicken breast were evaluated. Pectoralis major muscles containing water and sodium chloride, with or without sodium lactate, were browned and vacuum packaged. Sous vide processing was by fast or slow heating to an internal temperature of 77 or 94 C. Product was evaluated after 0, 14, and 28 d storage at 4 C. Quality was evaluated by gas chromatographic analyses of flavor volatiles, shear, color, and sensory panels. Incorporation of sodium lactate into brine did not influence oxidative stability (as measured by headspace gas chromatography) or sensory warmed-over flavor. Presence of sodium lactate did result in enhanced fresh roasted or meaty and saltiness sensory scores as well as a more yellow color. The more rapid heating rate decreased sulfur-containing compounds and did not influence other volatile concentrations. Products processed to 94 C were less juicy, less tender, and contained higher quantities of alcohols and hydrocarbons than those processed to 77 C. Storage resulted in a decline in fresh roasted or meaty flavor note and an increase in warmed-over flavor note and quantities of alcohols, aldehydes and ketones, hydrocarbons, and total headspace volatiles.

Volatile flavor compounds in yogurt: a review.

PubMed

Cheng, Hefa

2010-11-01

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

Influence of Aerosol Acidity on the Formation of Secondary Organic Aerosol from Biogenic Precursor Hydrocarbons

EPA Science Inventory

Secondary organic aerosol (SOA) formation and dynamics may be important factors for the role of aerosols in adverse health effects, visibility and climate change. Formation of SOA occurs when a parent volatile organic compound is oxidized to create products that form in a conden...

Contribution of first- versus second-generation products to secondary organic aerosols formed in the oxidation of biogenic hydrocarbons.

PubMed

Ng, Nga L; Kroll, Jesse H; Keywood, Melita D; Bahreini, Roya; Varutbangkul, Varuntida; Flagan, Richard C; Seinfeld, John H; Lee, Anita; Goldstein, Allen H

2006-04-01

Biogenic hydrocarbons emitted by vegetation are important contributors to secondary organic aerosol (SOA), but the aerosol formation mechanisms are incompletely understood. In this study, the formation of aerosols and gas-phase products from the ozonolysis and photooxidation of a series of biogenic hydrocarbons (isoprene, 8 monoterpenes, 4 sesquiterpenes, and 3 oxygenated terpenes) are examined. By comparing aerosol growth (measured by Differential Mobility Analyzers, DMAs) and gas-phase concentrations (monitored by a Proton Transfer Reaction Mass Spectrometer, PTR-MS), we study the general mechanisms of SOA formation. Aerosol growth data are presented in terms of a "growth curve", a plot of aerosol mass formed versus the amount of hydrocarbon reacted. From the shapes of the growth curves, it is found that all the hydrocarbons studied can be classified into two groups based entirely on the number of double bonds of the hydrocarbon, regardless of the reaction systems (ozonolysis or photooxidation) and the types of hydrocarbons studied: compounds with only one double bond and compounds with more than one double bond. For compounds with only one double bond, the first oxidation step is rate-limiting, and aerosols are formed mainly from low volatility first-generation oxidation products; whereas for compounds with more than one double bond, the second oxidation step may also be rate-limiting and second-generation products contribute substantially to SOA growth. This behavior is characterized by a vertical section in the growth curve, in which continued aerosol growth is observed even after all the parent hydrocarbon is consumed.

Changes on physico-chemical, textural, lipolysis and volatile compounds during the manufacture of dry-cured foal "cecina".

PubMed

Lorenzo, José M

2014-01-01

The changes in the physico-chemical and textural properties, lipolysis and volatile compounds during the manufacture of dry-cured foal "cecina" were studied. The pH increased during the last stages of processing but gradually declined over the curing period. TBARS values, hardness and chewiness increased with processing time from 0.14, 2.74 and 0.83 to 3.49 mg malonaldehyde/kg, 20.33 kg and 5.05 kg∗mm, respectively. Ripening time also affected the colour parameters: lightness (L*), redness (a*) and yellowness (b*) (P<0.001). The total average content of free fatty acid (FFA) increased significantly from 433.7 mg/100 g of fat in the raw pieces to 2655.5 mg/100 g of fat at the end of the drying-ripening stage. The main FFA at the end of the manufacturing process was palmitic acid (C16:0), followed by oleic (C18:1cis9), stearic (C18:0) and linoleic (C18:2n-6). A total of fifty five volatile compounds were identified during the manufacture of dry-cured foal "cecina", including esters, aldehydes, aliphatic hydrocarbons, branched hydrocarbons, alcohols, aromatic hydrocarbons, furans, ketones. Aldehydes reached their maximum level at the end of the post-salting stage. In the final product, esters became the dominant chemical compounds. © 2013.

Modeling comprehensive chemical composition of weathered oil following a marine spill to predict ozone and potential secondary aerosol formation and constrain transport pathways

NASA Astrophysics Data System (ADS)

Drozd, Greg T.; Worton, David R.; Aeppli, Christoph; Reddy, Christopher M.; Zhang, Haofei; Variano, Evan; Goldstein, Allen H.

2015-11-01

Releases of hydrocarbons from oil spills have large environmental impacts in both the ocean and atmosphere. Oil evaporation is not simply a mechanism of mass loss from the ocean, as it also causes production of atmospheric pollutants. Monitoring atmospheric emissions from oil spills must include a broad range of volatile organic compounds (VOC), including intermediate-volatile and semivolatile compounds (IVOC, SVOC), which cause secondary organic aerosol (SOA) and ozone production. The Deepwater Horizon (DWH) disaster in the northern Gulf of Mexico during Spring/Summer of 2010 presented a unique opportunity to observe SOA production due to an oil spill. To better understand these observations, we conducted measurements and modeled oil evaporation utilizing unprecedented comprehensive composition measurements, achieved by gas chromatography with vacuum ultraviolet time of flight mass spectrometry (GC-VUV-HR-ToFMS). All hydrocarbons with 10-30 carbons were classified by degree of branching, number of cyclic rings, aromaticity, and molecular weight; these hydrocarbons comprise ˜70% of total oil mass. Such detailed and comprehensive characterization of DWH oil allowed bottom-up estimates of oil evaporation kinetics. We developed an evaporative model, using solely our composition measurements and thermodynamic data, that is in excellent agreement with published mass evaporation rates and our wind-tunnel measurements. Using this model, we determine surface slick samples are composed of oil with a distribution of evaporative ages and identify and characterize probable subsurface transport of oil.

Comparision of real waste (MSW and MPW) pyrolysis in batch reactor over different catalysts. Part I: product yields, gas and pyrolysis oil properties.

PubMed

Ateş, Funda; Miskolczi, Norbert; Borsodi, Nikolett

2013-04-01

Pyrolysis of municipal solid waste (MSW) and municipal plastic waste (MPW) have been investigated in batch reactor at 500, 550 and 600°C both in absence and presence of catalysts (Y-zeolite, β-zeolite, equilibrium FCC, MoO3, Ni-Mo-catalyst, HZSM-5 and Al(OH)3). The effect of the parameters on the product properties was investigated. Products were characterized using gas-chromatography, GC/MS, (13)C NMR. Yields of volatile fractions increased, while reaction time necessity for the total cracking decreased in the presence of catalysts. Catalysts have productivity and selectivity in converting aliphatic hydrocarbons to aromatic and cyclic compounds in oil products. Gases from MSW consisted of hydrogen CO, CO2, while exclusively hydrogen and hydrocarbons were detected from MPW. Catalyst efficiency was higher using MPW than MSW. Pyrolysis oils contained aliphatic hydrocarbons, aromatics, cyclic compounds and less ketones, alcohols, acids or esters depending on the raw materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Variation in the chemical composition of cone volatiles within the African cycad genus Encephalartos.

PubMed

Suinyuy, Terence N; Donaldson, John S; Johnson, Steven D

2013-01-01

Volatiles play a key role in attraction of pollinators to cycad cones, but the extent to which volatile chemistry varies among cycad species is still poorly documented. Volatile composition of male and female cones of nineteen African cycad species (Encephalartos; Zamiaceae) was analysed using headspace technique and gas chromatography-mass spectrometry (GC-MS). A total of 152 compounds were identified among the species included in this study, the most common of which were monoterpenes, nitrogen-containing compounds and unsaturated hydrocarbons. Male and female cones emitted similar volatile compounds which varied in relative amounts with two unsaturated hydrocarbons (3E)-1,3-octadiene and (3E,5Z)-1,3,5-octatriene present in the volatile profile of most species. In a multivariate analysis of volatile profiles using non-metric multidimensional scaling (NMDS), a number of species clusters were identified according to shared emission of unsaturated hydrocarbons, pyrazines, benzenoids, aldehydes, alkanes and terpenoids. In comparison, terpenoids are common in Zamia and dominant in Macrozamia species (both in the family Zamiaceae) while benzenoids, esters, and alcohols are dominant in Cycas (Cycadaceae) and in Stangeria (Stangeriaceae). It is likely that volatile variation among Encephalartos species reflects both phylogeny and adaptations to specific beetle pollinators. Copyright © 2012 Elsevier Ltd. All rights reserved.

Volatile non-terpenoid hydrocarbons from Ligusticum grayi roots

USDA-ARS?s Scientific Manuscript database

The root essential oil of Ligusticum grayi Coult. & Rose (Apiaceae) contains three volatile non-terpenoid hydrocarbons: the known C11 compound viridene, whose structure is hereby corrected to 1-[(2Z)-pent-2-en-1-yl]cyclohexa-1,3-diene; and the heretofore unreported C10 compounds 1-[(2Z)-but-2-en-1-y...

Volatile organic compounds in a multi-storey shopping mall in guangzhou, South China

NASA Astrophysics Data System (ADS)

Tang, Jianhui; Chan, C. Y.; Wang, Xinming; Chan, L. Y.; Sheng, Guoying; Fu, Jiamo

Volatile organic compounds (VOCs) specified in the USEPA TO-14 list were analysed in microenvironments of a multi-storey shopping mall in Guangzhou city, South China. The microenvironments studied include both indoor (department store, supermarket, fast-food court, electronic games room, children's playground, gallery and book store) and outdoor ones (rooftop and ground level entrance). The characteristics and concentration of VOCs varied widely in differing microenvironments. The average concentrations of the total VOCs in the indoor microenvironments ranged from 178.5 to 457.7 μg m -3 with a maximum of 596.8 μg m -3. The fast-food court and a leather products department store had the highest concentrations of benzene, toluene, ethylbenzene, xylenes and chlorinated hydrocarbons. A high level of 1,4-dichlorobenzene was found in all indoor microenvironments with an average of 12.3 μg m -3 and a maximum of 44.3 μg m -3. The ratios of average indoor to outdoor concentrations (I/O ratio) in all indoor microenvironments fell between 1 and 3, except an average of 24.6 and a maximum of 77.8 in the fashion department store for 1,4-dichlorobenzene. Indoor emission sources of monocyclic aromatic hydrocarbons in the shopping mall might include cooking stoves, leather products and building materials. Chlorinated hydrocarbons, however, were possibly connected with their use as cleaning agents or deodorizers.

Hydrocarbon emissions speciation in diesel and biodiesel exhausts

NASA Astrophysics Data System (ADS)

Payri, Francisco; Bermúdez, Vicente R.; Tormos, Bernardo; Linares, Waldemar G.

Diesel engine emissions are composed of a long list of organic compounds, ranging from C 2 to C 12+, and coming from the hydrocarbons partially oxidized in combustion or produced by pyrolisis. Many of these are considered as ozone precursors in the atmosphere, since they can interact with nitrogen oxides to produce ozone under atmospheric conditions in the presence of sunlight. In addition to problematic ozone production, Brookes, P., and Duncan, M. [1971. Carcinogenic hydrocarbons and human cells in culture. Nature.] and Heywood, J. [1988. Internal Combustion Engine Fundamentals.Mc Graw-Hill, ISBN 0-07-1000499-8.] determined that the polycyclic aromatic hydrocarbons present in exhaust gases are dangerous to human health, being highly carcinogenic. The aim of this study was to identify by means of gas chromatography the amount of each hydrocarbon species present in the exhaust gases of diesel engines operating with different biodiesel blends. The levels of reactive and non-reactive hydrocarbons present in diesel engine exhaust gases powered by different biodiesel fuel blends were also analyzed. Detailed speciation revealed a drastic change in the nature and quantity of semi-volatile compounds when biodiesel fuels are employed, the most affected being the aromatic compounds. Both aromatic and oxygenated aromatic compounds were found in biodiesel exhaust. Finally, the conservation of species for off-side analysis and the possible influence of engine operating conditions on the chemical characterization of the semi-volatile compound phase are discussed. The use of oxygenated fuel blends shows a reduction in the Engine-Out emissions of total hydrocarbons. But the potential of the hydrocarbon emissions is more dependent on the compositions of these hydrocarbons in the Engine-Out, to the quantity; a large percent of hydrocarbons existing in the exhaust, when biodiesel blends are used, are partially burned hydrocarbons, and are interesting as they have the maximum reactivity, but with the use of pure biodiesel and diesel, the most hydrocarbons are from unburned fuel and they have a less reactivity. The best composition in the fuel, for the control of the hydrocarbon emissions reactivity, needs to be a fuel with high-saturated fatty acid content.

Ozonation of Canadian Athabasca asphaltene

NASA Astrophysics Data System (ADS)

Cha, Zhixiong

Application of ozonation in the petrochemical industry for heavy hydrocarbon upgrading has not been sufficiently explored. Among heavy hydrocarbons, asphaltenes are the heaviest and the most difficult fractions for analysis and treatment. Therefore, ozonation of asphaltenes presents an interesting application in the petrochemical industry. Commercial application of ozonation in the petrochemical industry has three obstacles: availability of an ozone-resistant and environmentally friendly solvent, the precipitation of ozonation intermediates during reaction, and recovery of the solvent and separation of the ozonation products. Preliminary ozonation of Athabasca oil sands asphaltene in nonparticipating solvents encountered serious precipitation of the ozonation intermediates. The precipitated intermediates could be polymeric ozonides and intermolecular ozonides or polymeric peroxides. Because the inhomogeneous reaction medium caused low ozone efficiency, various participating solvents such as methanol and acetic acid were added to form more soluble hydroperoxides. The mass balance results showed that on average, one asphaltene molecule reacted with 12 ozone molecules through the electrophilic reaction and the subsequent decomposition of ozonation intermediates generated acetone extractable products. GC/MS analysis of these compounds indicated that the free radical reactions could be important for generation of volatile products. The extensively ozonated asphaltene in the presence of participating solvents were refluxed with methanol to generate more volatile products. GC/MS analysis of the methanol-esterified ozonation products indicated that most volatile products were aliphatic carboxylic acid esters generated through cleavage of substituents. Reaction kinetics study showed that asphaltene ozonation was initially a diffusion rate-controlled reaction and later developed to a chemical reaction rate-controlled reaction after depletion of the reactive aromatic sites. Two new solvent systems, a self-sustaining ozonation system and a cyclohexane/acetone/water or a cyclohexane/acetone/methanol system, were studied to overcome the drawback of using halogenated solvents. The self-sustaining ozonation process employed the final ozonation products as the reaction solvent. Compared to the self-sustaining ozonation, the cyclohexane solvent system showed higher ozone efficiency; however, it required dynamic adjustment of the solvent system during ozonation. An extensively ozonated asphaltene's weight would be doubled. Distillation of the products separated about 45% volatile products having biodiesel-style chemical structures. Compared to distillation, more than 90% of the ozonation products were extractable by acetone. The remaining acetone-insoluble part was further classified by dichloromethane and other solvents of different polarities. The separated ozonation products were good fuel additives or materials for other products.

Profiles of Volatile Flavor Compounds in Milk Fermented with Different Proportional Combinations of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus.

PubMed

Dan, Tong; Wang, Dan; Wu, Shimei; Jin, Rulin; Ren, Weiyi; Sun, Tiansong

2017-09-29

Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus are key factors in the fermentation process and the final quality of dairy products worldwide. This study was performed to investigate the effects of the proportions of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus isolated from traditionally fermented dairy products in China and Mongolia on the profile of volatile compounds produced in samples. Six proportional combinations (1:1, 1:10, 1:50, 1:100, 1:1000, and 1:10,000) of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 were considered, and the volatiles were identified and quantified by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) against an internal standard. In total, 89 volatile flavor compounds, consisting of aldehydes, ketones, acids, alcohols, esters, and aromatic hydrocarbons, were identified. Among these, some key flavor volatile compounds were identified, including acetaldehyde, 3-methylbutanal, acetoin, 2-heptanone, acetic acid, butanoic acid, and 3-methyl-1-butanol. The of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 influenced the type and concentration of volatiles produced. In particular, aldehydes and ketones were present at higher concentrations in the 1:1000 treatment combination than in the other combinations. Our findings emphasize the importance of selecting the appropriate proportions of L. delbrueckii subsp. bulgaricus and S. thermophilus for the starter culture in determining the final profile of volatiles and the overall flavor of dairy products.

Lunar volatiles: a clue for understanding the evolution of the Moon and a resource to its exploration

NASA Astrophysics Data System (ADS)

Gerasimov, Mikhail

Introduction: The discovery of noticeable hydrogen concentration (believed to be in the form of water) in the polar regions was among the most exciting recent events in the exploration of the Moon. Concentration of water in polar regolith was estimated at a level of 4-6 wt.% [1,2]. Such high concentration of water in polar regolith on volatiles depleted Moon is probably a result of migration of water molecules from its hot equatorial latitudes to cold traps of the northern and southern polar regions. These depositions of volatiles on one hand contain important information on the evolution of the Moon and on the other hand their utilization can be a bases for the future human exploration. The question about diversity and source of the volatiles is still open. Sources of lunar volatiles: Three main possible sources of the Lunar polar volatiles are: Degassing of the interior. Endogenous source of volatiles is provided by degassing of heated interior of planetary bodies. In this case chemical composition of released gases reflects thermodynamic equilibrium of gases over typical magmas at temperatures around 1000°C. The composition of such gas mixtures is characterized by domination of H2O, CO2, and SO2 over other H, C, and S containing components. CO/CO2 ratio here is typically far below 0.1 level. Hydrocarbons are mainly aromatic hydrocarbons, alkanes, and cycloalkanes. Sulfur containing gases are mainly SO2, H2S, and Sx. Isotopic ratios of volatile elements should be the same as for the bulk Moon. Interaction of solar wind protons with surface rocks. Energetic solar wind protons with the absence of an atmospheric shield can react with oxygen of surface rocks and produce water molecules as end product. Such a mechanism provides a source of mainly water on the Moon with solar hydrogen isotopes and Moon rocks oxygen isotopes. Degassing of impacting meteorites and comets. Volatiles of impacting meteorites and comets are released into transient atmosphere. It was shown experimentally [3] that the forming gases are qualitatively similar for various rocky materials including meteorites of different classes. Such gas mixtures have the following characteristics: the CO/CO2 ratio is ³1, hydrocarbons are presented mainly by alkenes and PAHs, sulfur containing gases are presented by SO2, CS2, H2S, and COS in decreasing sequence, production of HCN, and noticeable release of water. Isotopic composition of volatile elements reflects the projectile to target proportion of their source. Gas-analytic package (GAP) of the Lunar-Resource mission: It is very important to investigate all the inventory of polar volatiles as well as isotopic composition of volatile elements to understand the real source of lunar volatiles and to evaluate their validity as a resource for the Moon exploration. The GAP is aimed on comprehensive investigation of the inventory of volatiles in the regolith of polar regions. It consists of three instruments: 1) Thermal Analyzer; 2) Gas Chromatograph with Tunable Diode Laser Absorption Spectrometer for isotopic measurements of H, O, and C in evolved gases; and 3) Neutral Gas Mass-Spectrometer. References: [1] Mitrofanov, I. G. et al. 2010. Science 330: 483-486. [2] Colaprete, A. et al. 2010. Science 330: 463-468. [3] Gerasimov, M.V. 2002. Geological Society of America Special Paper 356: 705-716. Acknowledgements: This work was supported by P-22 Program of the RAS.

Diffusion-based process for carbon dioxide uptake and isoprene emission in gaseous/aqueous two-phase photobioreactors by photosynthetic microorganisms.

PubMed

Bentley, Fiona K; Melis, Anastasios

2012-01-01

Photosynthesis for the generation of fuels and chemicals from cyanobacteria and microalgae offers the promise of a single host organism acting both as photocatalyst and processor, performing sunlight absorption and utilization, as well as CO(2) assimilation and conversion into product. However, there is a need to develop methods for generating, sequestering, and trapping such bio-products in an efficient and cost-effective manner that is suitable for industrial scale-up and exploitation. A sealed gaseous/aqueous two-phase photobioreactor was designed and applied for the photosynthetic generation of volatile isoprene (C(5)H(8)) hydrocarbons, which operates on the principle of spontaneous diffusion of CO(2) from the gaseous headspace into the microalgal or cyanobacterial-containing aqueous phase, followed by photosynthetic CO(2) assimilation and isoprene production by the transgenic microorganisms. Volatile isoprene hydrocarbons were emitted from the aqueous phase and were sequestered into the gaseous headspace. Periodic replacement (flushing) of the isoprene (C(5)H(8)) and oxygen (O(2)) content of the gaseous headspace with CO(2) allowed for the simultaneous harvesting of the photoproducts and replenishment of the CO(2) supply in the gaseous headspace. Reduction in practice of the gaseous/aqueous two-phase photobioreactor is offered in this work with a fed-batch and a semi-continuous culturing system using Synechocystis sp. PCC 6803 heterologously expressing the Pueraria montana (kudzu) isoprene synthase (IspS) gene. Constitutive isoprene production was observed over 192 h of experimentation, coupled with cyanobacterial biomass accumulation. The diffusion-based process in gaseous/aqueous two-phase photobioreactors has the potential to be applied to other high-value photosynthetically derived volatile molecules, emanating from a variety of photosynthetic microorganisms. Copyright © 2011 Wiley Periodicals, Inc.

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

PubMed

Wu, Haizhou; Zhuang, Hong; Zhang, Yingyang; Tang, Jing; Yu, Xiang; Long, Men; Wang, Jiamei; Zhang, Jianhao

2015-04-01

This study investigated the influence of partial substitution of NaCl with KCl on the formation of volatile compounds in bacons during processing using a purge and trap dynamic headspace GC/MS system. Three substitutions were 0% KCl (I), 40% KCl (II), and 70% KCl (III). The profiles of the volatile compounds significantly changed during processing, particularly during the drying/ripening. At the end of process, the bacons from substitution III formed significantly higher levels of lipid-derived volatiles, such as straight chain aldehydes, hydrocarbons than bacons from substitution I and II, whereas the latter formed higher levels of volatiles from amino acid degradation such as 3-methylbutanal. There were very few differences in volatile formation between 0% and 40% KCl application. These results suggest that K(+) substitution of Na(+) by more than 40% may significantly change profiles of volatiles in finished dry-cured bacons and therefore would result in changes in the product aroma and/or flavour. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determination of radiolysis products in gamma-irradiated multilayer barrier food packaging films containing a middle layer of recycled LDPE

NASA Astrophysics Data System (ADS)

Chytiri, Stavroula; Goulas, Antonios E.; Badeka, Anastasia; Riganakos, Kyriakos A.; Petridis, Dimitrios; Kontominas, Michael G.

2008-09-01

Volatile and non-volatile radiolysis products and sensory changes of five-layer food packaging films have been determined after gamma irradiation (5-60 kGy). Barrier films were based on polyamide (PA) and low-density polyethylene (LDPE). Each film contained a middle buried layer of recycled LDPE or 100% virgin LDPE (control samples). Data showed that a large number of radiolysis products were produced such as hydrocarbons, alcohols, carbonyl compounds, carboxylic acid. These compounds were detected in the food simulant after contact with all films even at the lower absorbed doses of 5 and 10 kGy. The type and concentration of radiolysis products increased progressively with radiation dose, while no new compounds were detected as a result of the presence of recycled LDPE. In addition, irradiation dose appears to influence the sensory properties of table water in contact with films.

Hydrocarbon concentrations at the Alpine mountain sites Jungfraujoch and Arosa

NASA Astrophysics Data System (ADS)

Li, Yingshi; Campana, Mike; Reimann, Stefan; Schaub, Daniel; Stemmler, Konrad; Staehelin, Johannes; Peter, Thomas

Volatile hydrocarbons have been measured for 1 yr at Arosa (2010 m asl) to determine the contribution of European emissions to the trace gas concentrations at this remote site. Results are compared to concurrent hydrocarbon concentrations at the high Alpine background site Jungfraujoch (3580 m asl). Hydrocarbon concentrations at Arosa are generally much higher than at Jungfraujoch. The influence of the Alpine boundary layer air was studied based on the diurnal variation of hydrocarbon concentrations, i.e. rising pollutant concentrations in the morning at Arosa and in the afternoon at Jungfraujoch. Different hydrocarbon emission sources of the uplifting air were found at the two sites. At Jungfraujoch, several transatlantic events were detected from October 2001 to January 2002 based on analysis of hydrocarbon ratios and air parcel trajectories. The OH concentration during the transatlantic transport was estimated to be around 5×10 5 cm -3, derived from simultaneous hydrocarbon oxidation and dilution in the free troposphere. These transatlantic transport events were tracked back to warm conveyor belts, characterized by uniform dynamics and relatively uniform surface sources. In addition, ozone production in the free tropospheric transport was also documented in these events.

δ 13C of free and macromolecular aromatic structures in the murchison meteorite

NASA Astrophysics Data System (ADS)

Sephton, M. A.; Pillinger, C. T.; Gilmour, I.

1998-05-01

Analyses of the organic compounds in the Murchison meteorite have led to a greater understanding of the nature of extraterrestrial organic materials. However, the relationship between low and high molecular weight material remains poorly understood. To investigate this relationship, untreated Murchison was subjected to supercritical fluid extraction (SFE) to obtain the free organic components in the meteorite. Toluene and other volatile aromatic hydrocarbons dominated the extract, and the carbon isotopic composition of these molecules was determined by gas chromatography-isotope ratio-mass spectrometry (GCIRMS). δ 13C values of the aromatic hydrocarbons ranged from -28.8 to -5.8‰. These compounds displayed a 13C-enrichment with increasing carbon number suggesting an origin by cracking. The high molecular weight organic material in the meteorite was isolated and subjected to hydrous pyrolysis. This procedure produced a number of aromatic products, the majority of which were volatile aromatic hydrocarbons, particularly toluene. SFE was used to extract and successfully retain them. This enabled the first carbon isotopic analysis of this poorly understood material to be performed at the molecular level by GCIRMS. δ 13C values for aromatic pyrolysis products occupied a range from -24.6 to -5.6‰. The trend of 13C-enrichment with increasing carbon number, observed in the free compounds, was also evident in the macromolecular fragments. Furthermore, the organic fragments of the macromolecular material were consistently 13C-enriched when compared to structurally identical free molecules. This suggested that the free aromatic hydrocarbons in Murchison were produced by the preterrestrial degradation of the organic macromolecular material. This natural degradation event was extended by the hydrous pyrolysis experiment.

Does switching to a tobacco-free waterpipe product reduce toxicant intake? A crossover study comparing CO, NO, PAH, volatile aldehydes, tar and nicotine yields

PubMed Central

Shihadeh, Alan; Salman, Rola; Jaroudi, Ezzat; Saliba, Najat; Sepetdjian, Elizabeth; Blank, Melissa D.; Cobb, Caroline O.; Eissenberg, Thomas

2012-01-01

Waterpipe (hookah, narghile, shisha) use has become a global phenomenon, with numerous product variations. One variation is a class of products marketed as “tobacco-free” alternatives for the “health conscious user”. In this study toxicant yields from waterpipes smoked using conventional tobacco-based and tobacco-free preparations were compared. A human-mimic waterpipe smoking machine was used to replicate the puffing sequences of 31 human participants who completed two double-blind ad libitum smoking sessions in a controlled clinical setting: once with a tobacco-based product of their choosing and once with a flavor-matched tobacco-free product. Outcome measures included yields of carbon monoxide, nitric oxide, volatile aldehydes, nicotine, tar, and polycyclic aromatic hydrocarbons. Smoke from both waterpipe preparations contained substantial quantities of toxicants. Nicotine yield was the only outcome that differed significantly between preparations. These findings contradict advertising messages that “herbal” waterpipe products are a healthy alternative to tobacco products. PMID:22406330

Total OH reactivity measurements for the OH-initiated oxidation of aromatic hydrocarbons in the presence of NOx

NASA Astrophysics Data System (ADS)

Sato, Kei; Nakashima, Yoshihiro; Morino, Yu; Imamura, Takashi; Kurokawa, Jun-ichi; Kajii, Yoshizumi

2017-12-01

The total OH reactivity of the secondary products formed from the OH-initiated oxidation of toluene, p-xylene, and 1,3,5-trimethylbenzene was directly measured in the presence of NOx using a laboratory environmental chamber in order to investigate unidentified reactive species in urban air. The total OH reactivity was also calculated from the concentrations of the reactants and products, which were monitored by Fourier-transform infrared spectroscopy. The difference between the measured and calculated OH reactivity, the so-called missing OH reactivity, comprised 58-81% of the total OH reactivity of the secondary products. These results suggest that the secondary products formed from the oxidation of aromatic hydrocarbons may be important candidates in accounting for the missing OH reactivity in the analyses of urban environments. The Master Chemical Mechanism (MCM) calculations were performed to predict the temporal variation in the total OH reactivity for the oxidation of aromatic hydrocarbons. The MCM calculations successfully reproduced the observed total OH reactivity when the particle and semi-volatile product concentrations were negligibly low. The MCM calculations were used to identify the missing secondary products. The results suggest that important components of the missing OH reactivity are unsaturated multifunctional products such as unsaturated dicarbonyls, unsaturated epoxydicarbonyls, and furanones.

29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 6 2013-07-01 2013-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from the...

29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 6 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from the...

29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 6 2011-07-01 2011-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from the...

29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 6 2012-07-01 2012-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from the...

29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 6 2014-07-01 2013-07-01 true Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from the...

Long-term evolution of biodegradation and volatilization rates in a crude oil-contaminated aquifer

USGS Publications Warehouse

Chaplin, B.P.; Delin, G.N.; Baker, R.J.; Lahvis, M.A.

2002-01-01

Volatilization and subsequent biodegradation near the water Table make up a coupled natural attenuation pathway that results in significant mass loss of hydrocarbons. Rates of biodegradation and volatilization were documented twice 12 years apart at a crude-oil spill site near Bemidji, Minnesota. Biodegradation rates were determined by calibrating a gas transport model to O2, CO2, and CH4 gas-concentration data in the unsaturated zone. Reaction stoichiometry was assumed in converting O2 and CO2 gas-flux estimates to rates of aerobic biodegradation and CH4 gas-flux estimates to rates of methanogenesis. Model results indicate that the coupled pathway has resulted in significant hydrocarbon mass loss at the site, and it was estimated that approximately 10.52 kg/day were lost in 1985 and 1.99 kg/day in 1997. In 1985 3% of total volatile hydrocarbons diffusing from the floating oil were biodegraded in the lower 1 m of the unsaturated zone and increased to 52% by 1997. Rates of hydrocarbon biodegradation above the center of the floating oil were relatively stable from 1985 to 1997, as the primary metabolic pathway shifted from aerobic to methanogenic biodegradation. Model results indicate that in 1997 biodegradation under methanogenenic conditions represented approximately one-half of total hydrocarbon biodegradation in the lower 1 m of the unsaturated zone. Further downgradient, where substrate concentrations have greatly increased, total biodegradation rates increased by greater than an order of magnitude from 0.04 to 0.43 g/m2-day. It appears that volatilization is the primary mechanism for attenuation in early stages of plume evolution, while biodegradation dominates in later stages.

Atomic Oxygen Interactions With Silicone Contamination on Spacecraft in Low Earth Orbit Studied

NASA Technical Reports Server (NTRS)

Banks, Bruce A.

2001-01-01

Silicones have been widely used on spacecraft as potting compounds, adhesives, seals, gaskets, hydrophobic surfaces, and atomic oxygen protective coatings. Contamination of optical and thermal control surfaces on spacecraft in low Earth orbit (LEO) has been an ever-present problem as a result of the interaction of atomic oxygen with volatile species from silicones and hydrocarbons onboard spacecraft. These interactions can deposit a contaminant that is a risk to spacecraft performance because it can form an optically absorbing film on the surfaces of Sun sensors, star trackers, or optical components or can increase the solar absorptance of thermal control surfaces. The transmittance, absorptance, and reflectance of such contaminant films seem to vary widely from very transparent SiOx films to much more absorbing SiOx-based films that contain hydrocarbons. At the NASA Glenn Research Center, silicone contamination that was oxidized by atomic oxygen has been examined from LEO spacecraft (including the Long Duration Exposure Facility and the Mir space station solar arrays) and from ground laboratory LEO simulations. The findings resulted in the development of predictive models that may help explain the underlying issues and effects. Atomic oxygen interactions with silicone volatiles and mixtures of silicone and hydrocarbon volatiles produce glassy SiOx-based contaminant coatings. The addition of hydrocarbon volatiles in the presence of silicone volatiles appears to cause much more absorbing (and consequently less transmitting) contaminant films than when no hydrocarbon volatiles are present. On the basis of the LDEF and Mir results, conditions of high atomic oxygen flux relative to low contaminant flux appear to result in more transparent contaminant films than do conditions of low atomic oxygen flux with high contaminant flux. Modeling predictions indicate that the deposition of contaminant films early in a LEO flight should depend much more on atomic oxygen flux than it does later in a mission.

Role of methyl group number on SOA formation from aromatic hydrocarbons photooxidation under low NOx conditions

NASA Astrophysics Data System (ADS)

Li, L.; Tang, P.; Nakao, S.; Chen, C.-L.; Cocker, D. R., III

2015-11-01

Substitution of methyl groups onto the aromatic ring determines the SOA formation from the aromatic hydrocarbon precursor. This study links the number of methyl groups on the aromatic ring to SOA formation from aromatic hydrocarbons photooxidation under low NOx conditions (HC / NO > 10 ppb C : ppb). Aromatic hydrocarbons with increasing numbers of methyl groups are systematically studied. SOA formation from pentamethylbenzene and hexamethylbenzene are reported for the first time. A decreasing SOA yield with increasing number of methyl groups is observed. Linear trends are found in both f44 vs. f43 and O / C vs. H / C for SOA from aromatic hydrocarbons with zero to six methyl groups. An SOA oxidation state predictive method based on benzene is used to examine the effect of added methyl groups on aromatic oxidation under low NOx conditions. Further, the impact of methyl group number on density and volatility of SOA from aromatic hydrocarbons is explored. Finally, a mechanism for methyl group impact on SOA formation is suggested. Overall, this work suggests as more methyl groups are attached on the aromatic ring, SOA products from these aromatic hydrocarbons become less oxidized per mass/carbon.

Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

PubMed

Võ, Uyên-Uyén T; Morris, Michael P

2014-06-01

Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test methodologies and ambient evaporation. This paper provides ample evidence to warrant a reevaluation of regulatory standards and provides a framework for progressive developments based on reasonable and scientifically justifiable definitions of VOCs.

Resolving the chemical structures of off-odorants and potentially harmful substances in toys-example of children's swords.

PubMed

Denk, Philipp; Velasco-Schön, Cristina; Buettner, Andrea

2017-09-01

Most children's toys on the market are primarily made out of plastic and other complex composite materials. Consumer complaints about offensive odors or irritating effects associated with toy products have increased in recent years. One example is the strongly perceivable negative odor reported for a particular series of toy swords. Characterizing the presence of contaminants, including those that have the potential to be deleterious to health, in such products is a significant analytical challenge due to the high baseline abundance of chemical constituents of the materials used in the products. In the present study, the nature of offensive odorants associated with toy sword products was examined by gas chromatography (GC). After initial sensory evaluations, the volatile compounds from the toy products were recovered using solvent extraction and solvent-assisted flavor evaporation. The extracts were analyzed using GC-olfactometry (GC-O) and two-dimensional GC-O coupled with mass spectrometry (GC-GC-MS/O). A total of 26 odor-active compounds, including aromatic hydrocarbons and phenols, were identified among numerous non-odorous volatile by-products. These substances also included polycyclic aromatic hydrocarbons, which were analyzed by GC-MS. Representative substances were naphthalene and 1,2-dihydronaphthalene that exhibited moldy, mothball-like odor impressions, and phenol derivatives with leather-like, phenolic, horse-stable-like smells. The odorants detected correlated with the assigned attributes from the sensory analyses. This study clearly shows that the detection and identification of such odorous contaminants can provide key indications of potentially harmful yet unknown substances in everyday products such as toys. Graphical abstract ᅟ.

Dose-dependent changes of chemical attributes in irradiated sausages.

PubMed

Nam, K C; Lee, E J; Ahn, D U; Kwon, J H

2011-05-01

To determine the effects of irradiation on the chemical attributes of sausages, TBARS values, volatile compounds, gaseous compounds, and hydrocarbons of vacuum-packaged sausages were analyzed during 60 d of refrigerated storage. A sulfur-containing volatile (dimethyl disulfide), a gas (methane), and radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane) were mainly detected in irradiated sausages and the concentrations of these compounds were irradiation dose-dependent with R(2) = 0.9585, 0.9431, and 0.9091-0.9977, respectively. Especially methane and a few hydrocarbons were detected only in irradiated sausages and their amounts were dose-dependent. On the other hand, TBARS values, other off-odor volatiles (carbon disulfide, hexanal), and gases (carbon monoxide, carbon dioxide) were found both in irradiated and nonirradiated sausages. Therefore, it is suggested that radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane), dimethyl disulfide, and methane can be used as markers for irradiated sausages. Copyright © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

Public health assessment for Pasley Solvents and Chemicals Inc. , Garden City, Nassau County, New York, Region 2. Cerclis No. NYD991292004. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1994-08-22

The Pasley Solvents and Chemicals site, which is on the National Priorities List, is situated between the borders of the Village of Garden City and Uniondale in the Town of Hempstead, Nassau County, New York. Soils at the site are contaminated with volatile organic compounds (VOCs), primarily solvent constituents and petroleum hydrocarbons compounds; semi-volatile compounds (primarily polycyclic aromatic hydrocarbon compounds); and several metals. Groundwater in the shallow and deep aquifers under the site is contaminated with VOCs, primarily solvent constituents and petroleum hydrocarbons compounds, and two semi-volatile compounds at the concentrations exceeding public health assessment comparison values. Limited information ismore » available on soil gas intrusion and indoor air contamination, and this pathway is of concern since occupied buildings are nearby and above contaminated groundwater plumes.« less

Holographic detection of hydrocarbon gases and other volatile organic compounds.

PubMed

Martínez-Hurtado, J L; Davidson, C A B; Blyth, J; Lowe, C R

2010-10-05

There is a need to develop sensors for real-time monitoring of volatile organic compounds (VOCs) and hydrocarbon gases in both external and indoor environments, since these compounds are of growing concern in human health and welfare. Current measurement technology for VOCs requires sophisticated equipment and lacks the prospect for rapid real-time monitoring. Holographic sensors can give a direct reading of the analyte concentration as a color change. We report a technique for recording holographic sensors by laser ablation of silver particles formed in situ by diffusion. This technique allows a readily available hydrophobic silicone elastomer to be transformed into an effective sensor for hydrocarbon gases and other volatile compounds. The intermolecular interactions present between the polymer and molecules are used to predict the sensor performance. The hydrophobicity of this material allows the sensor to operate without interference from water and other atmospheric gases and thus makes the sensor suitable for biomedical, industrial, or environmental analysis.

Pollution characteristics of volatile organic compounds, polycyclic aromatic hydrocarbons and phthalate esters emitted from plastic wastes recycling granulation plants in Xingtan Town, South China

NASA Astrophysics Data System (ADS)

Huang, De-Yin; Zhou, Shun-Gui; Hong, Wei; Feng, Wei-Feng; Tao, Liang

2013-06-01

With the aim to investigate the main pollution characteristics of exhaust gases emitted from plastic waste recycling granulation plants, mainly volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs) were analyzed in Xingtan Town, the largest distribution center of plastic waste recycling in China. Both inside and outside the plants, the total concentrations of volatile monocyclic aromatic hydrocarbons (MAHs), PAHs and PAEs ranged from 2000 to 3000 μg m-3, 450 to 1200 ng m-3, and 200 to 1200 ng m-3, respectively. Their concentration levels inside the plants were higher than those outside the plants, and PAHs and PAEs were mainly distributed in the gas-phase. Notably, highly toxic benzo[a]pyrene (BaP) could be detected inside the plants, and harmful PAEs could be detected not only inside but also outside the plants, although PAEs are non-volatile. The exhaust gas composition and concentration were related to the plastic feedstock and granulation temperature.

Volatile chemicals identified in extracts from leaves of Japanese mugwort (Artemisia princeps pamp.).

PubMed

Umano, K; Hagi, Y; Nakahara, K; Shoji, A; Shibamoto, T

2000-08-01

Extracts from leaves of Japanese mugwort (Artemisia princeps Pamp.) were obtained using two methods: steam distillation under reduced pressure followed by dichloromethane extraction (DRP) and simultaneous purging and extraction (SPSE). A total of 192 volatile chemicals were identified in the extracts obtained by both methods using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). They included 47 monoterpenoids (oxygenated monoterpenes), 26 aromatic compounds, 19 aliphatic esters, 18 aliphatic alcohols, 17 monoterpenes (hydrocarbon monoterpenes), 17 sesquiterpenes (hydrocarbon sesquiterpenes), 13 sesquiterpenoids (oxygenated sesquiterpenes), 12 aliphatic aldehydes, 8 aliphatic hydrocarbons, 7 aliphatic ketones, and 9 miscellaneous compounds. The major volatile constituents of the extract by DRP were borneol (10.27 ppm), alpha-thujone (3.49 ppm), artemisia alcohol (2.17 ppm), verbenone (1.85 ppm), yomogi alcohol (1.50 ppm), and germacren-4-ol (1.43 ppm). The major volatile constituents of the extract by SPSE were 1,8-cineole (8.12 ppm), artemisia acetate (4.22 ppm), alpha-thujone (3.20 ppm), beta-caryophyllene (2.39 ppm), bornyl acetate (2.05 ppm), borneol (1.80 ppm), and trans-beta-farnesene (1. 78 ppm).

High molecular weight non-polar hydrocarbons as pure model substances and in motor oil samples can be ionized without fragmentation by atmospheric pressure chemical ionization mass spectrometry.

PubMed

Hourani, Nadim; Kuhnert, Nikolai

2012-10-15

High molecular weight non-polar hydrocarbons are still difficult to detect by mass spectrometry. Although several studies have targeted this problem, lack of good self-ionization has limited the ability of mass spectrometry to examine these hydrocarbons. Failure to control ion generation in the atmospheric pressure chemical ionization (APCI) source hampers the detection of intact stable gas-phase ions of non-polar hydrocarbon in mass spectrometry. Seventeen non-volatile non-polar hydrocarbons, reported to be difficult to ionize, were examined by an optimized APCI methodology using nitrogen as the reagent gas. All these analytes were successfully ionized as abundant and intact stable [M-H](+) ions without the use of any derivatization or adduct chemistry and without significant fragmentation. Application of the method to real-life hydrocarbon mixtures like light shredder waste and car motor oil was demonstrated. Despite numerous reports to the contrary, it is possible to ionize high molecular weight non-polar hydrocarbons by APCI, omitting the use of additives. This finding represents a significant step towards extending the applicability of mass spectrometry to non-polar hydrocarbon analyses in crude oil, petrochemical products, waste or food. Copyright © 2012 John Wiley & Sons, Ltd.

Characterisation of volatile profiles in 50 native Peruvian chili pepper using solid phase microextraction-gas chromatography mass spectrometry (SPME-GCMS).

PubMed

Patel, Kirti; Ruiz, Candy; Calderon, Rosa; Marcelo, Mavel; Rojas, Rosario

2016-11-01

The volatiles were characterised by headspace solid phase micro extraction (HS-SPME), gas chromatography mass spectrometry (GC-FID/MS). A total of 127 compounds were identified with terpenes (including mono terpenes and sesquiterpenes - a total of 45 compounds), esters (31 compounds) and hydrocarbons (20 compounds) were the predominant volatile compounds. Principal component analysis (PCA) of the volatile compounds yielded 2 significant PC's, which together accounted for 90.3% of the total variance in the data set and the scatter plot generated between PC1 and PC2 successfully segregated the 50 chili pepper samples into 7 groups. Clusters of hydrocarbons, esters, terpenes, aldehyde and ketones formed the major determinants of the difference. Copyright © 2016 Elsevier Ltd. All rights reserved.

End product yields from the extraruminal fermentation of various polysaccharide, protein and nucleic acid components of biofuels feedstocks.

PubMed

Weimer, Paul J

2011-02-01

"Extraruminal" fermentations employing in vitro incubation of mixed ruminal bacterial consortia, are capable of converting a complex array of biomass materials to mixtures of volatile fatty acids (VFA), methane, and carbon dioxide. Most of the potential energy in the biomass feedstock is retained in the VFA products, which are potential reactants for electrochemical conversion to hydrocarbon fuels. Quantitative data on VFA yields and proportions from biomass components are necessary for determining industrial feasibility, but such measurements have not been systematically reported. VFA yields and proportions were determined for a variety of carbohydrates, proteins and nucleic acids. Carbohydrates yielded primarily acetic and propionic acids, while proteins also yielded a more favorable product mix (longer average chain length and branched chain VFAs). Addition of certain co-substrates (e.g., glycerol) favorably improved the VFA product mix. The results have implications for hydrocarbon fuel generation from biomass materials by hybrid fermentation/chemical processes. Published by Elsevier Ltd.

Intraspecific Signals Inducing Aggregation in Periplaneta americana (Insecta: Dictyoptera).

PubMed

Imen, Saïd; Christian, Malosse; Virginie, Durier; Colette, Rivault

2015-06-01

Chemical communication is necessary to induce aggregation and to maintain the cohesion of aggregates in Periplaneta americana (L.) cockroaches. We aimed to identify the chemical message inducing aggregation in this species. Two types of bioassays were used-binary choice tests in Petri dishes and tests in Y-olfactometer. Papers conditioned by direct contact of conspecifics induce aggregation when proposed in binary choice tests and were attractive in a Y-olfactometer. The identification of the molecules present on these conditioned papers indicated that dichloromethane extracts contained mainly cuticular hydrocarbons whereas methanol extracts contained more volatile molecules. Only a mixture of extracts in both solvents induced aggregation. High concentrations of cuticular hydrocarbons are necessary to induce aggregation when presented alone. When presented with volatile molecules present in methanol extracts, low concentrations of cuticular hydrocarbons are sufficient to induce aggregation if they are presented in contact. Among volatile molecules collected on filter paper, a mixture of three compounds-hexadecanoic acid, pentadecanoic acid, and pentaethylene glycol-induced aggregation. Our results provide evidence that aggregation processes in P. americana relies on a dual mechanism: attraction over long distances by three volatile molecules and maintenance on site by contact with cuticular hydrocarbons. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Assessment of soil pollution based on total petroleum hydrocarbons and individual oil substances.

PubMed

Pinedo, J; Ibáñez, R; Lijzen, J P A; Irabien, Á

2013-11-30

Different oil products like gasoline, diesel or heavy oils can cause soil contamination. The assessment of soils exposed to oil products can be conducted through the comparison between a measured concentration and an intervention value (IV). Several national policies include the IV based on the so called total petroleum hydrocarbons (TPH) measure. However, the TPH assessment does not indicate the individual substances that may produce contamination. The soil quality assessment can be improved by including common hazardous compounds as polycyclic aromatic hydrocarbons (PAHs) and aromatic volatile hydrocarbons like benzene, toluene, ethylbenzene and xylenes (BTEX). This study, focused on 62 samples collected from different sites throughout The Netherlands, evaluates TPH, PAH and BTEX concentrations in soils. Several indices of pollution are defined for the assessment of individual variables (TPH, PAH, B, T, E, and X) and multivariables (MV, BTEX), allowing us to group the pollutants and simplify the methodology. TPH and PAH concentrations above the IV are mainly found in medium and heavy oil products such as diesel and heavy oil. On the other hand, unacceptable BTEX concentrations are reached in soils contaminated with gasoline and kerosene. The TPH assessment suggests the need for further action to include lighter products. The application of multivariable indices allows us to include these products in the soil quality assessment without changing the IV for TPH. This work provides useful information about the soil quality assessment methodology of oil products in soils, focussing the analysis into the substances that mainly cause the risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

Analyzing the flavor compounds in Chinese traditional fermented shrimp pastes by HS-SPME-GC/MS and electronic nose

NASA Astrophysics Data System (ADS)

Fan, Yan; Yin, Li'ang; Xue, Yong; Li, Zhaojie; Hou, Hu; Xue, Changhu

2017-04-01

Shrimp paste is a type of condiments with high nutritional value. However, the flavors of shrimp paste, particularly the non-uniformity flavors, have limited its application in food processing. In order to identify the characteristic flavor compounds in Chinese traditional shrimp pastes, five kinds of typical commercial products were evaluated in this study. The differences in the volatile composition of the five products were investigated. Solid phase micro-extraction method was employed to extract the volatile compounds. GC-MS and electronic nose were applied to identify the compounds, and the data were analyzed using principal component analysis (PCA). A total of 62 volatile compounds were identified, including 8 alcohols, 7 aldehydes, 3 ketones, 7 ethers, 7 acids, 3 esters, 6 hydrocarbons, 12 pyrazines, 2 phenols, and 7 other compounds. The typical volatile compounds contributing to the flavor of shrimp paste were found as follows: dimethyl disulfide, dimethyl tetrasulfide, dimethyl trisulfide, 2, 3, 5-trimethyl-6-ethyl pyrazine, ethyl-2, 5-dimethyl-pyrazine, phenol and indole. Propanoic acid, butanoic acid, furans, and 2-hydroxy-3-pentanone caused unpleasant odors, such as pungent and rancid odors. Principal component analysis showed that the content of volatile compounds varied depending on the processing conditions and shrimp species. These results indicated that the combinations of multiple analysis and identification methods could make up the limitations of a single method, enhance the accuracy of identification, and provide useful information for sensory research and product development.

Kinetic modeling of secondary organic aerosol formation: effects of particle- and gas-phase reactions of semivolatile products

NASA Astrophysics Data System (ADS)

Chan, A. W. H.; Kroll, J. H.; Ng, N. L.; Seinfeld, J. H.

2007-08-01

The distinguishing mechanism of formation of secondary organic aerosol (SOA) is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics), of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.

Kinetic modeling of Secondary Organic Aerosol formation: effects of particle- and gas-phase reactions of semivolatile products

NASA Astrophysics Data System (ADS)

Chan, A. W. H.; Kroll, J. H.; Ng, N. L.; Seinfeld, J. H.

2007-05-01

The distinguishing mechanism of formation of secondary organic aerosol (SOA) is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics), of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.

Passive soil gas technique for investigating soil and groundwater plume emanating from volatile organic hydrocarbon at Bazian oil refinery site.

PubMed

Hamamin, Dara Faeq

2018-05-01

The current work is an attempt to illustrate the importance of using passive soil gas as an innovative investigation technique in the assessment of soil and groundwater pollutions that emanates from volatile hydrocarbon activities in newly emerging countries. Bazian Oil Refinery as one of the largest refinery in Iraqi Kurdistan Region produces 40,000 barrels a day and provides a wide range of petroleum products for daily consumption. The types and scale of different process that happen in this industrial site have led to concerns with regard to its impact on both the soil and groundwater the vicinity of the factory. The researcher conducted a combined sampling design with a dual-phased extraction procedure for soil vapor and groundwater samples in order to assess the susceptibility of the subsurface to pollution with hydrocarbon. The aims were to characterize potential source(s), map the areal extent of the site which is at risk to be affected with the identified9 hydrocarbon compounds and vapor. A collection kit from Beacon Environmental Service was used to collect a total number of 50 passive soil vapors in the first step of work. To extrapolate results, five shallow boring for soils and six for water sampling were carefully observed. The selection of the sampling points was based on the results revealed by the PSG survey that showed significant quantities of analyzed organic hydrocarbon for a follow-up investigation. The matrices were analyzed by ALS Laboratory to target more than 40 VOCs and SVOCs. The plan was to make the mass to concentration tie-in for the selected analyzed compounds (Benzene, Toluene, and Total Petroleum Hydrocarbons) from the PSG in mass (nanograms) with both the soil and water samples in concentration. The results revealed that the PSG technique is unique in identifying the source and extent of soil and groundwater pollutions plume. Copyright © 2017 Elsevier B.V. All rights reserved.

Potential of select intermediate-volatility organic compounds and consumer products for secondary organic aerosol and ozone formation under relevant urban conditions

NASA Astrophysics Data System (ADS)

Li, Weihua; Li, Lijie; Chen, Chia-li; Kacarab, Mary; Peng, Weihan; Price, Derek; Xu, Jin; Cocker, David R.

2018-04-01

Emissions of certain low vapor pressure-volatile organic compounds (LVP-VOCs) are considered exempt to volatile organic compounds (VOC) regulations due to their low evaporation rates. However, these compounds may still play a role in ambient secondary organic aerosol (SOA) and ozone formation. The LVP-VOCs selected for this work are categorized as intermediate-volatility organic compounds (IVOCs) according to their vapor pressures and molecular formulas. In this study, the evaporation rates of 14 select IVOCs are investigated with half of them losing more than 95% of their mass in less than one month. Further, SOA and ozone formation are presented from 11 select IVOCs and 5 IVOC-containing generic consumer products under atmospherically relevant conditions using varying radical sources (NOx and/or H2O2) and a surrogate reactive organic gas (ROG) mixture. Benzyl alcohol (0.41), n-heptadecane (0.38), and diethylene glycol monobutyl ether (0.16) are determined to have SOA yields greater than 0.1 in the presence of NOx and a surrogate urban hydrocarbon mixture. IVOCs also influence ozone formation from the surrogate urban mixture by impacting radical levels and NOx availability. The addition of lab created generic consumer products has a weak influence on ozone formation from the surrogate mixture but strongly affects SOA formation. The overall SOA and ozone formation of the generic consumer products could not be explained solely by the results of the pure IVOC experiments.

Volatile organic compound concentrations in the South Coast Air Basin (CA) during the summers of 1995 and 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zielinska, B.; Harshfield, G.; Fujita, E.

1997-12-31

Volatile organic compounds (VOC) were measured in California`s South Coast Air Basin (SoCAB) during the summers of 1995 and 1996 in order to determine the air quality impacts of the introduction in 1996 of California`s Phase 2 reformulated gasoline (RFG). Over 250 canister and 2,4-dinitrophenylhydrazine (DNPH)-impregnated cartridge samples were collected during each sampling campaign at four sampling sites--two source-dominated sites, a downwind receptor site, and a background site. Canister samples were analyzed for methane, speciated volatile hydrocarbons (C{sub 2}-C{sub 12}), carbon monoxide (CO), carbon dioxide (CO{sub 2}), and methyl tert-butyl ether (MTBE). DNPH were analyzed for C{sub 1}-C{sub 7} carbonylmore » compounds. This paper examines the changes in concentrations of C{sub 2}-C{sub 12} hydrocarbons in the SoCAB resulting from the introduction of Phase 2 RFG with particular emphasis on hydrocarbon species that are most affected by the reformulation.« less

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

PubMed

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

2012-06-10

To evaluate postmortem intervals (PMIs), one should take into account the determined age of necrophagous flies present on the cadaver. However, PMI determination needs further improvement, and rapid and accurate approaches have therefore to be developed. While previous studies have focussed on insect cuticular hydrocarbons, here we explore the volatile profile released by larvae and pupae of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). We monitored changes in volatile compounds daily, by headspace solid-phase microextraction, followed by gas chromatography-mass spectrometry. Branched and unbranched hydrocarbons, alcohols, esters and acids were identified, and the volatile profile was shown to vary, in both composition and quantity, with the age of the larva/pupa under investigation. We concluded, based on the analysis of the released volatile organic compounds, that it is possible to increase the accuracy of the estimated PMI, through improved estimation of the age of blowflies present on the cadaver. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Volatile organic compounds up to C 20 emitted from motor vehicles; measurement methods

NASA Astrophysics Data System (ADS)

Zielinska, Barbara; Sagebiel, John C.; Harshfield, Gregory; Gertler, Alan W.; Pierson, William R.

To understand better the sources of observed differences between on-road vehicle emissions and model estimates, and to evaluate the emission of ozone precursors from motor vehicles, a series of experiments was conducted in the Fort McHenry Tunnel, Baltimore, Maryland (18-24 June 1992), and in the Tuscarora Mountain Tunnel, Pennsylvania (2-8 September 1992). Samples were collected using stainless steel canisters (whole air samples, analyzed for C 2C 12 hydrocarbons), Tenax-TA solid adsorbent cartridges (for semi-volatile hydrocarbons, in the C 8C 20 range), and 2,4-dinitrophenylhydrazine (DNPH) impregnated cartridges (for carbonyl compounds). The samples were analyzed using high resolution gas chromatographic separation with Fourier transform infrared/mass spectrometric detection (GC/IRD/ MSD) for qualitative identification and with flame ionization detection (GC/FID) for quantitation of hydrocarbons, and high performance liquid chromatography (HPLC) for identification and quantitation of carbonyl compounds. A custom-designed database management system was used to handle the large data sets generated by these analyses. From the evaluation of canister and Tenax sample stability upon storage, it was found that hydrocarbons in the C 8C 12 range seemed to be more stable in the Tenax cartridge than in the canister. The effect of the Nafion® dryer (frequently used for moisture removal prior to cryogenic concentration of the canister samples) was also assessed and it was found to lower the measured concentrations of hydrocarbons collected in the canisters. Comparison of hydrocarbon concentrations found in the Tenax and canister samples allows an assessment of the contribution of semi-volatile hydrocarbons (C 10C 20 range derived from Tenax data) to the total non-methane hydrocarbons (C 2C 20, derived from canisters and Tenax data). The results of this study show that hydrocarbons in the range of C 10C 20 are important components of gas-phase hydrocarbons emitted from heavy-duty diesel vehicles (they account for approximately half of the total gas-phase non-methane hydrocarbon emission rates) and hence that solid adsorbent sampling should be used in addition to canister sampling in measurements of motor vehicle emissions.

Estimation of rates of aerobic hydrocarbon biodegradation by simulation of gas transport in the unsaturated zone

USGS Publications Warehouse

Lahvis, Matthew A.; Baehr, Arthur L.

1996-01-01

The distribution of oxygen and carbon dioxide gases in the unsaturated zone provides a geochemical signature of aerobic hydrocarbon degradation at petroleum product spill sites. The fluxes of these gases are proportional to the rate of aerobic biodegradation and are quantified by calibrating a mathematical transport model to the oxygen and carbon dioxide gas concentration data. Reaction stoichiometry is assumed to convert the gas fluxes to a corresponding rate of hydrocarbon degradation. The method is applied at a gasoline spill site in Galloway Township, New Jersey, to determine the rate of aerobic degradation of hydrocarbons associated with passive and bioventing remediation field experiments. At the site, microbial degradation of hydrocarbons near the water table limits the migration of hydrocarbon solutes in groundwater and prevents hydrocarbon volatilization into the unsaturated zone. In the passive remediation experiment a site-wide degradation rate estimate of 34,400 g yr−1 (11.7 gal. yr−1) of hydrocarbon was obtained by model calibration to carbon dioxide gas concentration data collected in December 1989. In the bioventing experiment, degradation rate estimates of 46.0 and 47.9 g m−2 yr−1(1.45 × 10−3 and 1.51 × 10−3 gal. ft.−2yr−1) of hydrocarbon were obtained by model calibration to oxygen and carbon dioxide gas concentration data, respectively. Method application was successful in quantifying the significance of a naturally occurring process that can effectively contribute to plume stabilization.

POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) AND OTHER SEMI-VOLATILE ORGANIC COMPOUNDS COLLECTED IN NEW YORK CITY IN RESPONSE TO THE EVENTS OF 9/11

EPA Science Inventory

Concentrations of over 60 non-polar semi-volatile and non-volatile organic compounds were measured in Lower Manhattan, New York using a high capacity Integrated Organic Gas and Particle Sampler, after the initial destruction of the World Trade Center. The results indicate that th...

POLYCYLIC AROMATIC HYDROCARBONS (PAHS) AND OTHER SEMI-VOLATILE ORGANIC COMPOUNDS COLLECTED IN NEW YORK CITY IN RESPONSE TO THE EVENTS OF 9/11

EPA Science Inventory

Concentrations of over 60 non-polar semi-volatile and non-volatile organic compounds were measured in Lower Manhattan, New York using a high capacity Integrated Organic Gas an Particle Sampler, after the initial destruction of the World Trade Center. The results indicate that t...

POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) AND OTHER SEMI-VOLATILE ORGANIC COMPOUNDS COLLECTED IN NEW YORK CITY IN RESPONSE TO THE EVENTS OF 9/11

EPA Science Inventory

Concentrations of over 60 non-polar semi-volatile and non-volatile organic compounds were measured in Lower Manhattan, New York using a high capacity Integrated Organic Gas and Particle Sampler, after the initial destruction of the World Trade Center. The results indicate that ...

Isogermacrene A, a proposed intermediate in sesquiterpene biosynthesis.

PubMed

Hackl, Thomas; König, Wilfried A; Muhle, Hermann

2004-08-01

In the essential oil of the liverwort Saccogyna viticulosa, collected on the island of Madeira, the new sesquiterpene hydrocarbons isogermacrene A (5) and its Cope rearrangement product iso-beta-elemene (6) were identified. 5 is proposed to act as the biogenetic precursor of several new sesquiterpenes identified in the volatiles of S. viticulosa. These include iso-alpha-humulene, alpha-gorgonene, gorgona-1,4(15), 11-triene and gorgon- 11-en-4-ol. In addition, the Cope product of zierene, isozierene, allo-aromadendra-4(15),10(14)-diene, aromadendra-4(15),10(14)-dien-1-ol and a prenylguaiane diterpene alcohol, named viticulol, were identified as new natural products.

Overview of air pollution and endocrine disorders

PubMed Central

Darbre, Philippa D

2018-01-01

Over recent years, many environmental pollutant chemicals have been shown to possess the ability to interfere in the functioning of the endocrine system and have been termed endocrine disrupting chemicals (EDCs). These compounds exist in air as volatile or semi-volatile compounds in the gas phase or attached to particulate matter. They include components of plastics (phthalates, bisphenol A), components of consumer goods (parabens, triclosan, alkylphenols, fragrance compounds, organobromine flame retardants, fluorosurfactants), industrial chemicals (polychlorinated biphenyls), products of combustion (polychlorinated dibenzodioxins/furans, polyaromatic hydrocarbons), pesticides, herbicides, and some metals. This review summarizes current knowledge concerning the sources of EDCs in air, measurements of levels of EDCs in air, and the potential for adverse effects of EDCs in air on human endocrine health. PMID:29872334

Bioavailability of Volatile Organics and Other Hydrocarbons from Environmental Media: Ingestion in Drinking Water.

DTIC Science & Technology

1992-05-19

NO. 61102F 23-12 A4 1 N/A I 1 . TITLE (Include Security Classification) Bioavailability of Volatile Organics and Other Hydrocarbons from Environmental...450 isozymes necessary for metabolic activation of CCI4 to cytotoxic metabolites. 92-15622 I 1 I1 1 111 I2II l i IIl 926 I BIOAVAILAEILITY OF...Research By 1 Bolling Air Force Base, DC 20332-6448 Dist ibutionl Dist I. OVERALL OBJECTIVE AND SPECIFIC AIMS The OVERALL OBJECTIVE of the project was to

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

PubMed

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

2015-05-15

107 kinds of C₂-C₁₂ volatile organic compound (VOC) mass concentrations and profiles for four types of coal-fired stationary sources in Liaoning Province were studied by a dilution sampling system and GC-MS analysis method, which are of significant importance with regard to VOC emissions in northeast of China. The results showed that there were some differences among these VOC source profiles. The total mass concentrations of analyzed 107 VOC species varied from 10,917 to 19,652 μg m(-3). Halogenated hydrocarbons exhibited higher mass percentages for the VOC source profiles of iron smelt (48.8%) and coke production plant (37.7%). Aromatic hydrocarbons were the most abundant in heating station plant (69.1%). Ketones, alcohols and acetates held 45.0% of total VOCs in thermal power plant. For non-methane hydrocarbons (NMHCs), which are demanded for photochemical assessment in the USA, toluene and n-hexane were the most abundant species in the iron smelt, coke production and thermal power plant, with the mass percentages of 64.8%, 52.7% and 38.6%, respectively. Trimethylbenzene, n-propylbenzene and o,m-ethyltoluene approximately accounted for 70.0% in heating station plant. NMHCs emitted from coke production, iron smelt, heating station and power plant listed above presented different chemical reactivities. The average OH loss rate of NMHCs from heating station, was 4 to 5.6 times higher than that of NMHCs from iron smelt, coke production and power plant, which implies that VOCs emitted from heating station in northeast of China should be controlled firstly to avoid photochemical ozone pollution and protect human health. There are significant variations in the ratios of benzene/toluene and m, p-xylene/ethylbenzene of these coal-fired source profiles. The representativeness of the coal-fired sources studied and the VOC samples collected should be more closely examined. The accuracy of VOC source profiles related to coal-fired processes is highly dependent on location and sampling method. Copyright © 2015 Elsevier B.V. All rights reserved.

Modelling Poly-Aromatic Hydrocarbons "online" with the GEOS-Chem Europe and Asia regional models.

NASA Astrophysics Data System (ADS)

Ivatt, P.; Evans, M. J.

2017-12-01

Poly-Aromatic Hydrocarbons (PAHs) are carcinogens and so are restricted by international treaties. PAHs are mainly emitted into the atmosphere by domestic (heating and cooking), natural (forest fires burning), as well as some industrial processes (coke ovens). PAHs partition between the gas and particle phase (notably carbonaceous particles) based on their volatility. In recent years, interest has turned to the possible health effects of their oxidation products (both nitrogenated and oxygenated) as it has been suggested that these oxidation products may be even more carcinogenic than the parent PAHs. To increase our understanding of the processes controlling the regional concentrations of PAHs and their oxidation products an "online" PAH model has been developed within the GEOS-Chem framework. This provides for the representation of the coupled aerosol/gas phase chemistry of the parent PAH and its secondary oxidation products. Benzo[a]pyrene is used as an exemplar but the methodology is flexible and the approach can be used for any PAH species. Comparisons are made with observations and the sources of variability discussed.

Role of methyl group number on SOA formation from monocyclic aromatic hydrocarbons photooxidation under low-NOx conditions

NASA Astrophysics Data System (ADS)

Li, L.; Tang, P.; Nakao, S.; Chen, C.-L.; Cocker, D. R., III

2016-02-01

Substitution of methyl groups onto the aromatic ring determines the secondary organic aerosol (SOA) formation from the monocyclic aromatic hydrocarbon precursor (SOA yield and chemical composition). This study links the number of methyl groups on the aromatic ring to SOA formation from monocyclic aromatic hydrocarbons photooxidation under low-NOx conditions (HC/NO > 10 ppbC : ppb). Monocyclic aromatic hydrocarbons with increasing numbers of methyl groups are systematically studied. SOA formation from pentamethylbenzene and hexamethylbenzene are reported for the first time. A decreasing SOA yield with increasing number of methyl groups is observed. Linear trends are found in both f44 vs. f43 and O / C vs. H / C for SOA from monocyclic aromatic hydrocarbons with zero to six methyl groups. An SOA oxidation state predictive method based on benzene is used to examine the effect of added methyl groups on aromatic oxidation under low-NOx conditions. Further, the impact of methyl group number on density and volatility of SOA from monocyclic aromatic hydrocarbons is explored. Finally, a mechanism for methyl group impact on SOA formation is suggested. Overall, this work suggests that, as more methyl groups are attached on the aromatic ring, SOA products from these monocyclic aromatic hydrocarbons become less oxidized per mass/carbon on the basis of SOA yield or chemical composition.

AGRONOMIC OPTIMIZATION FOR PHYTOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBONS

EPA Science Inventory

Phytoremediation is a low-cost method of using plants to degrade, volatilize or sequester organic and metal pollutants that has been used in efforts to remediate sites contaminated with polycyclic aromatic hydrocarbon (PAH) refinery wastes. Non-native plant species aggressivel...

The effects of diet and breed on the volatile compounds of cooked lamb.

PubMed

Elmore, J S; Mottram, D S; Enser, M; Wood, J D

2000-06-01

The effect of varying the n-3 polyunsaturated fatty acid (PUFA) composition of lamb muscle on the formation of aroma volatiles during cooking has been examined. The meat was obtained from four groups of Suffolk and Soay lambs fed different supplementary fats: a palm-oil based control; bruised whole linseed, which increased muscle levels of α-linolenic acid (C18:3 n-3); fish oil, which increased eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3); and equal quantities of linseed and fish oil (fat basis). Higher quantities of lipid oxidation products were found in the aroma volatiles of lamb muscle from animals fed fish oil, compared to the control. In particular, unsaturated aldehydes, unsaturated hydrocarbons and alkylfurans increased up to fourfold. These compounds derived from the autoxidation of PUFAs during cooking. Although some of these volatiles were increased in meat from animals fed the linseed supplement, the effect was not as great as with the fish oil fed lambs. Levels of volatiles derived from the Maillard reaction, such as pyrazines and sulfur compounds, were up to four times higher in Soays than Suffolks.

Characterization of Volatile Compounds with HS-SPME from Oxidized n-3 PUFA Rich Oils via Rancimat Tests.

PubMed

Yang, Kai-Min; Cheng, Ming-Ching; Chen, Chih-Wei; Tseng, Chin-Yin; Lin, Li-Yun; Chiang, Po-Yuan

2017-02-01

Algae oil and fish oil are n-3 PUFA mainstream commercial products. The various sources for the stability of n-3 PUFA oxidation are influenced by the fatty acid composition, extraction and refined processing. In this study, the oil stability index (OSI) occurs within 2.3 to 7.6 hours with three different n-3 PUFA rich oil. To set the OSI in the Rancimat test as the oil stability limit and observed various degrees of oxidation (0, 25, 50, 75, 100 and 125%). The volatile oxidation compounds were analyzed via headspace-solid phase microextraction (HS-SPME) and GC/MS. We detected 51 volatile compound variations during the oxidation, which were composed of aldehydes, hydrocarbons, cyclic compounds, alcohols, benzene compounds, ketones, furans, ester and pyrrolidine. The off-flavor characteristics can be strongly influenced by the synergy effects of volatile oxidation compounds. Chemometric analysis (PCA and AHC) was applied to identify the sensitive oxidation marker compounds, which included a (E,E)-2,4-heptadienal appropriate marker, via lipid oxidation in the n-3 PUFA rich oil.

Effect of post-fermentation and packing stages on the volatile composition of Spanish-style green table olives.

PubMed

Sánchez, Antonio Higinio; López-López, Antonio; Cortés-Delgado, Amparo; Beato, Víctor Manuel; Medina, Eduardo; de Castro, Antonio; Montaño, Alfredo

2018-01-15

The volatile profile of Spanish-style green table olives after fermentation and the changes in volatile compounds that occurred as a result of the post-fermentation and subsequent packing stage were explored by solid phase micro-extraction (SPME) and gas chromatography coupled to mass spectrometry (GC-MS). Three olive cultivars (Manzanilla, Gordal, and Hojiblanca) were processed and olive samples were taken at three different times throughout the elaboration: after fermentation, after post-fermentation, and after packing. A total of 132 volatile compounds were identified, including 10 phenols, 25 alcohols, 11 acids, 39 esters, 8 hydrocarbons, 14 carbonyl compounds, 17 terpenes, and 6 other compounds. A varying number of compounds from each chemical family underwent significant changes because of the post-fermentation and packing stages. Among them, some typical reaction products of lipid oxidation (e.g. (E)-2-decenal and (E,E)-2,4-decadienal) increased with the post-fermentation in Manzanilla cultivar, and also as a result of packing in all three cultivars. Copyright © 2017 Elsevier Ltd. All rights reserved.

Volatile compounds of sulfur in the Fe-C-S system at 5.3 GPa and 1300°C

NASA Astrophysics Data System (ADS)

Zhimulev, E. I.; Sonin, V. M.; Bul'bak, T. A.; Chepurov, A. I.; Tomilenko, A. A.; Pokhilenko, N. P.

2015-05-01

This report presents the results of experimental studies of the fluid phase in the Fe-C-S system at high P and T values (5.3 GPa and 1300°C) conforming to diamond synthesis. The samples for experiments were mounted on air; therefore, the volatile compounds detected after the experiments are characterized by a wide variety and complicated composition involving both inorganic and organic components. Among the inorganic compounds, CO2, H2O, N2, SO2, CS2, and COS were detected. The GC/MS analysis revealed hydrocarbons (paraffins, olefins, and arenes), including high-molecular compounds. The formation of heavy hydrocarbons confirms their thermodynamic stability under high pressure. Oxygenated hydrocarbons (alcohols, aldehydes, ketones, carboxylic acids, and ethers) were also detected.

Volatile profiles of Italian monovarietal extra virgin olive oils via HS-SPME-GC-MS: newly identified compounds, flavors molecular markers, and terpenic profile.

PubMed

Cecchi, Teresa; Alfei, Barbara

2013-12-01

This study aims to contribute to the knowledge of the commercial, sensory, and analytical characteristics of extra virgin olive oil (EVOO) from Italy (Marche region), renowned since ancient times. Headspace solid-phase micro-extraction (HS-SPME) was applied for the very first time to the sampling of volatile compounds of eleven typical Italian monocultivar EVOOs. Forty-eight compounds were characterised by GC-MS, some of them were only occasionally found in other EVOOs and some other were never detected before in any EVOO. Compounds belonging mainly to alcohols, esters, aldehydes, ketones and hydrocarbons chemical classes characterised the volatile profiles. The main volatile compounds detected in the EVOOs were the C6 compounds derived from polyunsaturated fatty acids, through the lipoxygenase pathway, in different proportion according to the specific cultivar. The results suggest that genetic factors strongly influence volatile formation and terpene hydrocarbons are claimed to be suitable markers of the geographic origin and genotype of the EVOO. Correlations among sensory attributes evaluated by a panel test and the presence of specific volatile compounds were highlighted for the very first time. The significance of the presence of some newly identified volatile compounds was discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Atmospheric hydrocarbon emissions and concentrations in the barnett shale natural gas production region.

PubMed

Zavala-Araiza, Daniel; Sullivan, David W; Allen, David T

2014-05-06

Hourly ambient hydrocarbon concentration data were collected, in the Barnett Shale Natural Gas Production Region, using automated gas chromatography (auto-GC), for the period from April 2010 to December 2011. Data for three sites were compared: a site in the geographical center of the natural gas production region (Eagle Mountain Lake (EML)); a rural/suburban site at the periphery of the production region (Flower Mound Shiloh), and an urban site (Hinton). The dominant hydrocarbon species observed in the Barnett Shale region were light alkanes. Analyses of daily, monthly, and hourly patterns showed little variation in relative composition. Observed concentrations were compared to concentrations predicted using a dispersion model (AERMOD) and a spatially resolved inventory of volatile organic compounds (VOC) emissions from natural gas production (Barnett Shale Special Emissions Inventory) prepared by the Texas Commission on Environmental Quality (TCEQ), and other emissions information. The predicted concentrations of VOC due to natural gas production were 0-40% lower than background corrected measurements, after accounting for potential under-estimation of certain emission categories. Hourly and daily variations in observed, background corrected concentrations were primarily explained by variability in meteorology, suggesting that episodic emission events had little impact on hourly averaged concentrations. Total emissions for VOC from natural gas production sources are estimated to be approximately 25,300 tons/yr, when accounting for potential under-estimation of certain emission categories. This region produced, in 2011, approximately 5 bcf/d of natural gas (100 Gg/d) for a VOC to natural gas production ratio (mass basis) of 0.0006.

Pyrolytic product characteristics of biosludge from the wastewater treatment plant of a petrochemical industry.

PubMed

Lin, Kuo-Hsiung; Hsu, Hui-Tsung; Ko, Ya-Wen; Shieh, Zhu-Xin; Chiang, Hung-Lung

2009-11-15

Biosludge was produced from the wastewater treatment plant of a petrochemical industry. The element compositions of pyrolytic residues, CO, CO(2), NOx, SOx, total hydrocarbons and detailed volatile organic compounds of pyrolytic gas, and C, H, N, S content and compositions in biofuel were determined in this study. Generally, 75-80% water content in sludge cakes and about 65-70% weight of water vapor and volatile compounds were volatilized during the drying process. Propene, propane, 1-butene, n-butane, isobutene, toluene and benzene were the major volatile organic compounds (VOCs) of the pyrolytic gas, and the concentrations for most of the top 20 VOC species were greater than 5 ppm. C(5)-C(9) compounds contributed 60% by weight of biofuel; 4-hydroxy-4-methyl-2-pentanone was the highest species, accounting for 28-53% of biofuel at various pyrolytic temperatures. Based on the dried residues, there was 8.5-13% weight in pyrolytic residues, 62-82% weight in liquid products (water and crude oil) and 5.8-30% weight in the gas phase after pyrolytic processing at 500-800 degrees C. Finally, 1.5-2.5 wt% liquid fuel was produced after the distillation process. The pyrolytic residues could be reused, the pyrolytic liquid product could be used as a fuel after distillation, and the pyrolytic gas could be recycled in the pyrolytic process to achieve non-toxic discharge and reduce the cost of sludge disposal.

Inverse Opal Photonic Crystals as an Optofluidic Platform for Fast Analysis of Hydrocarbon Mixtures.

PubMed

Xu, Qiwei; Mahpeykar, Seyed Milad; Burgess, Ian B; Wang, Xihua

2018-06-13

Most of the reported optofluidic devices analyze liquid by measuring its refractive index. Recently, the wettability of liquid on various substrates has also been used as a key sensing parameter in optofluidic sensors. However, the above-mentioned techniques face challenges in the analysis of the relative concentration of components in an alkane hydrocarbon mixture, as both refractive indices and wettabilities of alkane hydrocarbons are very close. Here, we propose to apply volatility of liquid as the key sensing parameter, correlate it to the optical property of liquid inside inverse opal photonic crystals, and construct powerful optofluidic sensors for alkane hydrocarbon identification and analysis. We have demonstrated that via evaporation of hydrocarbons inside the periodic structure of inverse opal photonic crystals and observation of their reflection spectra, an inverse opal film could be used as a fast-response optofluidic sensor to accurately differentiate pure hydrocarbon liquids and relative concentrations of their binary and ternary mixtures in tens of seconds. In these 3D photonic crystals, pure chemicals with different volatilities would have different evaporation rates and can be easily identified via the total drying time. For multicomponent mixtures, the same strategy is applied to determine the relative concentration of each component simply by measuring drying time under different temperatures. Using this optofluidic sensing platform, we have determined the relative concentrations of ternary hydrocarbon mixtures with the difference of only one carbon between alkane hydrocarbons, which is a big step toward detailed hydrocarbon analysis for practical use.

Remedial Investigation/Feasibility Study/Interim Response Actions

DTIC Science & Technology

1988-03-25

organosulfur compounds (CC/FP), organophosphorus compounds (CC/FPD), hydrocarbons (CC/FID), volatile aromatic compounds (GC/ PID ), volatile halogenated...ICP metals, mercury and arsenic (AA). Water samples are being analyzed for volatile halogenated organics (GC/CON), volatile aromatic organics (GC/ PID ...Feb Mar Apr May Jun Jul Aug SepSI - I I I I I • .. I I I ----+----- 685 27-90 so ONSITE DISPOSAL FACILITY .i * 686 27-01 Prep FLUE Plan Fz=m8u> 6e7

[Influence of liquid or solid culture conditions on the volatile components of mycelia of Isariacateinannulata].

PubMed

Zhang, Delong; Wang, Xiaodong; Lu, Ruili; Li, Kangle; Hu, Fenglin

2011-12-01

To determine the volatile components of mycelia of Isaria cateinannulata cultured under different culture conditions, and to analyze the relationships between the culture conditions and volatile metabolites. Mycelia were cultured in solid plates with SDAY medium and liquid shake flasks with SDY medium. The culture conditions were at 25 degrees C and 8 days. Volatile components in the mycelia of I. cateinannulata were extracted with simultaneous distillation extraction and analyzed by gas chromatography-mass spectrometry. Alkenes, alkanes, heterocyclic and polycyclic aromatic hydrocarbons (PAH) were existed abundantly both in the mycelia of liquid and solid cultures, but the kinds and relative concentrations of the volatile components in mycelia of liquid and solid cultures were very different. Forty-one compounds were identified from the mycelia of solid culture and 32 compounds were identified from the mycelia of liquid culture. Esters, quinones and oximes were only found in solid cultured mycelia whereas carboxylic acids were only discovered in the mycelia of liquid culture. At the same time, mycelia of liquid culture contained much more phenols. The most abundant compounds in mycelia of liquid and solid cultures were hydrocarbons. The volatile extracts of solid cultured mycelia contained 57.6% alkenes and 9.19% alkanes. The volatile extracts of liquid cultured mycelia contained 7.85% alkenes and 22.4% alkanes. Liquid or solid culture conditions influenced the volatile components of mycelia of I. cateinannulata.

Contaminant risks from biosolids land application: contemporary organic contaminant levels in digested sewage sludge from five treatment plants in Greater Vancouver, British Columbia.

PubMed

Bright, D A; Healey, N

2003-01-01

This study examines the potential for environmental risks due to organic contaminants at sewage sludge application sites, and documents metals and various potential organic contaminants (volatile organics, chlorinated pesticides, PCBs, dioxins/furans, extractable petroleum hydrocarbons, PAHs, phenols, and others) in current production biosolids from five wastewater treatment plants (WWTPs) within the Greater Vancouver Regional District (GVRD). There has been greater focus in Europe, North America and elsewhere on metals accumulation in biosolids-amended soil than on organic substances, with the exception of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. Another objective, therefore, was to evaluate the extent to which management of biosolids re-use based on metal/metalloid levels coincidentally minimizes environmental risks from organic contaminants. Historical-use contaminants such as chlorophenols, PCBs, and chlorinated pesticides were not detected at environmentally relevant concentrations in any of the 36 fresh biosolids samples, and appear to have virtually eliminated from sanitary collection system inputs. The few organic contaminants found in freshly produced biosolids samples that exhibited high concentrations relative to British Columbia and Canadian soil quality benchmarks included p-cresol, phenol, phenanthrene, pyrene, naphthalene, and heavy extractable petroleum hydrocarbons (HEPHs--nCl9-C34 effective carbon chain length). It was concluded that, with the exception of these petroleum hydrocarbon constituents or their microbial metabolites, the mixing of biosolids with uncontaminated soils during land application and based on the known metal concentrations in biosolids from the Greater Vancouver WWTPs investigated provides adequate protection against the environmental risks associated with organic substances such as dioxins and furans, phthalate esters, or volatile organics. Unlike many other organic contaminants, the concentrations of petroleum hydrocarbon derived substances in biosolids has not decreased within the last decade or more in the WWTPs studied, and--unlike persistent chlorinated compounds--the associated PAHs and other hydrocarbon constituents merit careful consideration, especially in the context of repeated land-application of biosolid.

Biofuel components change the ecology of bacterial volatile petroleum hydrocarbon degradation in aerobic sandy soil.

PubMed

Elazhari-Ali, Abdulmagid; Singh, Arvind K; Davenport, Russell J; Head, Ian M; Werner, David

2013-02-01

We tested the hypothesis that the biodegradation of volatile petroleum hydrocarbons (VPHs) in aerobic sandy soil is affected by the blending with 10 percent ethanol (E10) or 20 percent biodiesel (B20). When inorganic nutrients were scarce, competition between biofuel and VPH degraders temporarily slowed monoaromatic hydrocarbon degradation. Ethanol had a bigger impact than biodiesel, reflecting the relative ease of ethanol compared to methyl ester biodegradation. Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes revealed that each fuel mixture selected for a distinct bacterial community, each dominated by Pseudomonas spp. Despite lasting impacts on soil bacterial ecology, the overall effects on VHP biodegradation were minor, and average biomass yields were comparable between fuel types, ranging from 0.40 ± 0.16 to 0.51 ± 0.22 g of biomass carbon per gram of fuel carbon degraded. Inorganic nutrient availability had a greater impact on petroleum hydrocarbon biodegradation than fuel composition. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bioremediation of PAHs and VOCs: Advances in clay mineral-microbial interaction.

PubMed

Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

2015-12-01

Bioremediation is an effective strategy for cleaning up organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Advanced bioremediation implies that biotic agents are more efficient in degrading the contaminants completely. Bioremediation by microbial degradation is often employed and to make this process efficient, natural and cost-effective materials can serve as supportive matrices. Clay/modified clay minerals are effective adsorbents of PAHs/VOCs, and readily available substrate and habitat for microorganisms in the natural soil and sediment. However, the mechanism underpinning clay-mediated biodegradation of organic compounds is often unclear, and this requires critical investigation. This review describes the role of clay/modified clay minerals in hydrocarbon bioremediation through interaction with microbial agents in specific scenarios. The vision is on a faster, more efficient and cost-effective bioremediation technique using clay-based products. This review also proposes future research directions in the field of clay modulated microbial degradation of hydrocarbons. Copyright © 2015 Elsevier Ltd. All rights reserved.

Highly elevated atmospheric levels of volatile organic compounds in the Uintah Basin, Utah.

PubMed

Helmig, D; Thompson, C R; Evans, J; Boylan, P; Hueber, J; Park, J-H

2014-05-06

Oil and natural gas production in the Western United States has grown rapidly in recent years, and with this industrial expansion, growing environmental concerns have arisen regarding impacts on water supplies and air quality. Recent studies have revealed highly enhanced atmospheric levels of volatile organic compounds (VOCs) from primary emissions in regions of heavy oil and gas development and associated rapid photochemical production of ozone during winter. Here, we present surface and vertical profile observations of VOC from the Uintah Basin Winter Ozone Studies conducted in January-February of 2012 and 2013. These measurements identify highly elevated levels of atmospheric alkane hydrocarbons with enhanced rates of C2-C5 nonmethane hydrocarbon (NMHC) mean mole fractions during temperature inversion events in 2013 at 200-300 times above the regional and seasonal background. Elevated atmospheric NMHC mole fractions coincided with build-up of ambient 1-h ozone to levels exceeding 150 ppbv (parts per billion by volume). The total annual mass flux of C2-C7 VOC was estimated at 194 ± 56 × 10(6) kg yr(-1), equivalent to the annual VOC emissions of a fleet of ∼100 million automobiles. Total annual fugitive emission of the aromatic compounds benzene and toluene, considered air toxics, were estimated at 1.6 ± 0.4 × 10(6) and 2.0 ± 0.5 × 10(6) kg yr(-1), respectively. These observations reveal a strong causal link between oil and gas emissions, accumulation of air toxics, and significant production of ozone in the atmospheric surface layer.

DEMONSTRATION BULLETIN: IN SITU STEAM ENHANCED RECOVERY PROCESS - HUGHES ENVIRONMENTAL SYSTEMS, INC.

EPA Science Inventory

The Steam Enhanced Recovery Process (SERP) is designed to remove volatile compounds such as halogenated solvents and petroleum hydrocarbons, and semi-volatile compounds from contaminated soils in situ. The vapor pressures of most contaminants will increase by the addition of ste...

Analysis of the thermal reaction products of para polyphenylene by combined gas chromatography-mass spectrometry

NASA Technical Reports Server (NTRS)

Fewell, L. L.

1976-01-01

Analysis of the volatiles and sublimate produced when para-polyphenylene is pyrolyzed to constant weight under vacuum in the temperature range from 380 to 1000 C indicates that the polymer undergoes thermal degradation in two stages. The first stage involved dehydrohalogenation, which is essentially a curing reaction that produces crosslinking between polyphenylene chains resulting from the loss of chlorine from the polymer in the form of hydrogen chloride. The second stage of the thermal degradation is dehydrogenation because hydrogen is the major volatile species. Increasing amounts of polycyclic aromatic hydrocarbons (phenanthrene and 9, 10 benzphenanthrene) in the sublimate, concomitant with increasing C/H ratios of the polymeric residue with pyrolysis temperature, is consistent with the buildup of polynuclear structures in the polymer matrix.

Experiment to Characterize Aircraft Volatile Aerosol and Trace-Species Emissions (EXCAVATE)

NASA Technical Reports Server (NTRS)

Anderson, B. E.; Branham, H.-S.; Hudgins, C. H.; Plant, J. V.; Ballenthin, J. O.; Miller, T. M.; Viggiano, A. A.; Blake, D. R.; Boudries, H.; Canagaratna, M.

2005-01-01

The Experiment to Characterize Aircraft Volatile and Trace Species Emissions (EXCAVATE) was conducted at Langley Research Center (LaRC) in January 2002 and focused upon assaying the production of aerosols and aerosol precursors by a modern commercial aircraft, the Langley B757, during ground-based operation. Remaining uncertainty in the postcombustion fate of jet fuel sulfur contaminants, the need for data to test new theories of particle formation and growth within engine exhaust plumes, and the need for observations to develop air quality models for predicting pollution levels in airport terminal areas were the primary factors motivating the experiment. NASA's Atmospheric Effects of Aviation Project (AEAP) and the Ultra Effect Engine Technology (UEET) Program sponsored the experiment which had the specific objectives of determining ion densities; the fraction of fuel S converted from S(IV) to S(VI); the concentration and speciation of volatile aerosols and black carbon; and gas-phase concentrations of long-chain hydrocarbon and PAH species, all as functions of engine power, fuel composition, and plume age.

Volatile organic compound measurements in the California/Mexico border region during SCOS97

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zielinska, B.; Sagebiel, J.; Uberna, E.

1999-07-01

Measurements of volatile organic compounds (VOC) were carried out in the California/Mexico border region during the Southern California Ozone study in the Summer of 1997 (SCOS97). Integrated 3-hr samples were collected in Rosarito (south of Tijuana, Mexico) and in Mexicali during Intensive Operational Periods (IOP), twice per IOP day. VOC were collected using stainless-steel 6 L canisters; carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated C{sub 18} SepPak cartridges. The canister samples were analyzed for speciated volatile hydrocarbons (C{sub 2}-C{sub 12}), CO, CO{sub 2}, CH{sub 4}, MTBE, and halogenated hydrocarbons. DNPH-impregnated cartridges were analyzed for fourteen C{sub 1}-C{sub 7} carbonylmore » compounds. The results of these measurements will be discussed.« less

FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND CARBONACEOUS SOLIDS IN GAS-PHASE CONDENSATION EXPERIMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaeger, C.; Huisken, F.; Henning, Th.

2009-05-01

Carbonaceous grains represent a major component of cosmic dust. In order to understand their formation pathways, they have been prepared in the laboratory by gas-phase condensation reactions such as laser pyrolysis and laser ablation. Our studies demonstrate that the temperature in the condensation zone determines the formation pathway of carbonaceous particles. At temperatures lower than 1700 K, the condensation by-products are mainly polycyclic aromatic hydrocarbons (PAHs) that are also the precursors or building blocks for the condensing soot grains. The low-temperature condensates contain PAH mixtures that are mainly composed of volatile three to five ring systems. At condensation temperatures highermore » than 3500 K, fullerene-like carbon grains and fullerene compounds are formed. Fullerene fragments or complete fullerenes equip the nucleating particles. Fullerenes can be identified as soluble components. Consequently, condensation products in cool and hot astrophysical environments such as cool and hot asymptotic giant branch stars or Wolf-Rayet stars should be different and should have distinct spectral properties.« less

Profiling of volatile fragrant components in a mini-core collection of mango germplasms from seven countries

PubMed Central

Zhan, Ru-Lin; Wu, Hong-Xia; Yao, Quan-Sheng; Xu, Wen-Tian; Luo, Chun; Zhou, Yi-Gang; Liang, Qing-Zhi; Wang, Song-Biao

2017-01-01

Aroma is important in assessing the quality of fresh fruit and their processed products, and could provide good indicators for the development of local cultivars in the mango industry. In this study, the volatile diversity of 25 mango cultivars from China, America, Thailand, India, Cuba, Indonesia, and the Philippines was investigated. The volatile compositions, their relative contents, and the intervarietal differences were detected with headspace solid phase microextraction tandem gas chromatography-mass spectrometer methods. The similarities were also evaluated with a cluster analysis and correlation analysis of the volatiles. The differences in mango volatiles in different districts are also discussed. Our results show significant differences in the volatile compositions and their relative contents among the individual cultivars and regions. In total, 127 volatiles were found in all the cultivars, belonging to various chemical classes. The highest and lowest qualitative abundances of volatiles were detected in ‘Zihua’ and ‘Mallika’ cultivars, respectively. Based on the cumulative occurrence of members of the classes of volatiles, the cultivars were grouped into monoterpenes (16 cultivars), proportion and balanced (eight cultivars), and nonterpene groups (one cultivars). Terpene hydrocarbons were the major volatiles in these cultivars, with terpinolene, 3-carene, caryophyllene and α-Pinene the dominant components depending on the cultivars. Monoterpenes, some of the primary volatile components, were the most abundant aroma compounds, whereas aldehydes were the least abundant in the mango pulp. β-Myrcene, a major terpene, accounted for 58.93% of the total flavor volatile compounds in ‘Xiaofei’ (Philippens). γ-Octanoic lactone was the only ester in the total flavor volatile compounds, with its highest concentration in ‘Guiya’ (China). Hexamethyl cyclotrisiloxane was the most abundant volatile compound in ‘Magovar’ (India), accounting for 46.66% of the total flavor volatiles. A typical aldehydic aroma 2,6-di-tert-butyl-4-sec-butylphenol, was detected in ‘Gleck’. A highly significant positive correlation was detected between Alc and K, Alk and Nt, O and L. Cultivars originating from America, Thailand, Cuba, India, Indonesia and the Philippines were more similar to each other than to those from China. This study provides a high-value dataset for use in development of health care products, diversified mango breeding, and local extension of mango cultivars. PMID:29211747

Toxic remediation

DOEpatents

Matthews, Stephen M.; Schonberg, Russell G.; Fadness, David R.

1994-01-01

What is disclosed is a novel toxic waste remediation system designed to provide on-site destruction of a wide variety of hazardous organic volatile hydrocarbons, including but not limited to halogenated and aromatic hydrocarbons in the vapor phase. This invention utilizes a detoxification plenum and radiation treatment which transforms hazardous organic compounds into non-hazardous substances.

The contribution of evaporative emissions from gasoline vehicles to the volatile organic compound inventory in Mexico City.

PubMed

Schifter, I; Díaz, L; Rodríguez, R; González-Macías, C

2014-06-01

The strategy for decreasing volatile organic compound emissions in Mexico has been focused much more on tailpipe emissions than on evaporative emissions, so there is very little information on the contribution of evaporative emissions to the total volatile organic compound inventory. We examined the magnitudes of exhaust and evaporative volatile organic compound emissions, and the species emitted, in a representative fleet of light-duty gasoline vehicles in the Metropolitan Area of Mexico City. The US "FTP-75" test protocol was used to estimate volatile organic compound emissions associated with diurnal evaporative losses, and when the engine is started and a journey begins. The amount and nature of the volatile organic compounds emitted under these conditions have not previously been accounted in the official inventory of the area. Evaporative emissions from light-duty vehicles in the Metropolitan Area of Mexico City were estimated to be 39 % of the total annual amount of hydrocarbons emitted. Vehicles built before 1992 (16 % of the fleet) were found to be responsible for 43 % of the total hydrocarbon emissions from exhausts and 31 % of the evaporative emissions of organic compounds. The relatively high amounts of volatile organic compounds emitted from older vehicles found in this study show that strong emission controls need to be implemented in order to decrease the contribution of evaporative emissions of this fraction of the fleet.

Effect of volatile hydrocarbon fractions on mobility and earthworm uptake of polycyclic aromatic hydrocarbons from soils and soil/lampblack mixtures.

PubMed

Bogan, Bill W; Beardsley, Kate E; Sullivan, Wendy R; Hayes, Thomas D; Soni, Bhupendra K

2005-01-01

Studies were conducted to examine the mobility and bioavailability to earthworms (Eisenia fetida) of priority pollutant polycyclic aromatic hydrocarbons (PAH) in a suite of 11 soils and soil/lampblack mixtures obtained from former manufactured-gas plant sites. Contaminant mobility was assessed using XAD4 resins encapsulated in dialysis tubing, which were exposed to slurried soils for 15 d. These experiments showed that mobility of PAH in the different soils strongly correlated to the levels of volatile hydrocarbons (namely, gasoline- and diesel-range organics [GRO and DRO]) that existed in the soils as co-contaminants. Actual PAH bioavailability (as measured by earthworm PAH concentrations) also appeared to depend on GRO + DRO levels, although this was most evident at high levels of these contaminants. These findings are discussed in view of the effects of dieselrange organics on oil viscosity, assuming that the hydrocarbon contaminants in these soils exist in the form of distinct adsorbed oil phases. This study, therefore, extends correlations between carrier-oil viscosity and dissolved solute bioavailability, previously observed in a number of other in vitro and whole-organism tests (and in bacterial mutagenicity studies in soil), to multicellular organisms inhabiting contaminated-soil systems.

Volatile hydrocarbons and fuel oxygenates: Chapter 12

USGS Publications Warehouse

Cozzarelli, Isabelle M.

2014-01-01

Petroleum hydrocarbons and fuel oxygenates are among the most commonly occurring and widely distributed contaminants in the environment. This chapter presents a summary of the sources, transport, fate, and remediation of volatile fuel hydrocarbons and fuel additives in the environment. Much research has focused on the transport and transformation processes of petroleum hydrocarbons and fuel oxygenates, such as benzene, toluene, ethylbenzene, and xylenes and methyl tert‐butyl ether, in groundwater following release from underground storage tanks. Natural attenuation from biodegradation limits the movement of these contaminants and has received considerable attention as an environmental restoration option. This chapter summarizes approaches to environmental restoration, including those that rely on natural attenuation, and also engineered or enhanced remediation. Researchers are increasingly combining several microbial and molecular-based methods to give a complete picture of biodegradation potential and occurrence at contaminated field sites. New insights into the fate of petroleum hydrocarbons and fuel additives have been gained by recent advances in analytical tools and approaches, including stable isotope fractionation, analysis of metabolic intermediates, and direct microbial evidence. However, development of long-term detailed monitoring programs is required to further develop conceptual models of natural attenuation and increase our understanding of the behavior of contaminant mixtures in the subsurface.

Groundwater quality from private domestic water-supply wells in the vicinity of petroleum production in southwestern Indiana

USGS Publications Warehouse

Risch, Martin R.; Silcox, Cheryl A.

2016-06-02

The U.S. Geological Survey provided technical support to the Agency for Toxic Substances and Disease Registry for site selection and sample collection and analysis in a 2012 investigation of groundwater quality from 29 private domestic water-supply wells in the vicinity of petroleum production in southwestern Indiana. Petroleum hydrocarbons, oil and grease, aromatic volatile organic compounds, methane concentrations greater than 8,800 micrograms per liter, chloride concentrations greater than 250 milligrams per liter, and gross alpha radioactivity greater than 15 picocuries per liter were reported in the analysis of groundwater samples from 11 wells.

Superfund Record of Decision (EPA Region 6): Lincoln Creosote Site, Bossier City, LA, November 26, 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-10-01

The Lincoln Creosote Site (Site) is located in Bossier City, Louisiana, and consists of a 20-acre industrial area that includes the former location of a wood treatment plant. Wood products such as railroad ties and utility poles were pressure treated at the plant, using creosote, chromated copper-arsenate (CCA) and pentachlorophenol (PCP) as wood preservatives. The compounds used for wood treatment contained metals, a number of semi-volatile organic base-neutral extractable compounds such as polynuclear aromatic hydrocarbon (PAHs). EPA`s selected removal action called for excavation of residential soils containing concentrations of wood treatment product residuals.

FATE OF PAH COMPOUNDS IN TWO SOIL TYPES: INFLUENCE OF VOLATILIZATION, ABIOTIC LOSS, AND BIOLOGICAL ACTIVITY

EPA Science Inventory

The fate of 14 polycyclic aromatic hydrocarbon (PAH) compounds was evaluated with regard to interphase transfer potential and mechanisms of treatment in soil under unsaturated conditions. Volatilization and abiotic and biotic fate of the PAHs were determined using two soils not p...

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

PubMed Central

Górska, Ewa; Nowicka, Katarzyna; Jaworska, Danuta; Przybylski, Wiesław; Tambor, Krzysztof

2017-01-01

Objective The aim of this work was to determine the relationship between objective sensory descriptors and volatile flavour compound composition of Polish traditional dry-cured loin. Methods The volatile compounds were investigated by using solid phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS). For sensory assessment, the quantitative descriptive analysis (QDA) method was used. Results A total of 50 volatile compounds were found and assigned to 17 chemical families. Most of the detected volatile compounds derived from smoking, lipid oxidative reactions and seasoning (46.8%, 21.7%, and 18.9%, respectively). The dominant compounds were: aromatic hydrocarbon (toluene); alkanes (hexane, heptane, and 2,2,4-trimethylpentane); aldehyde (hexanal); alcohol (2-furanmethanol); ketone (3-hydroxy-2-butanone); phenol (guaiacol); and terpenes (eucalyptol, cymene, γ-terpinen, and limonene). Correlation analysis showed that some compounds derived from smoking were positively correlated with the intensity of cured meat odour and flavour and negatively with the intensity of dried meat odour and flavour, while terpenes were strongly correlated with odour and flavour of added spices. Conclusion The analysed dry-cured loins were characterized by specific and unique sensory profile. Odour and flavour of studied loins was mainly determined by volatile compounds originating from smoking, seasoning and lipid oxidation. Obtained results suggest that smoking process is a crucial stage during Polish traditional dry-cured loins production. PMID:27456422

San Francisco Deep Ocean Dredged Material Disposal Site (SF-DODS) Monitoring Program. Physical, Chemical, and Benthic Community Monitoring

DTIC Science & Technology

2003-08-29

analyzed for total volatile solids, total organic carbon, oil and grease/total petroleum hydrocarbons , grain size distribution, metals, polycyclic...TBT Tri-Butyltin TOC Total Organic Carbon TPCB Total Polychlorinated Biphenyls TPH Total Petroleum Hydrocarbons USACE U.S. Army Corps of Engineers U.S...Health PQL Practical Quantitation Limit RCRA Resource Conservation and Recovery Act SIM Selected Ion Monitoring TPH Total Petroleum Hydrocarbons tr Trace

Degradation and Volatilization of Chlorofluorocarbons in Contaminated Groundwater Explored by Stable Carbon Isotope Analysis

NASA Astrophysics Data System (ADS)

Horst, A.; Lacrampe-Couloume, G.; Sherwood Lollar, B.

2015-12-01

Chlorofluorocarbons (CFCs) are ozone depleting compounds whose production was phased out by the regulations of the Montreal Protocol (1987). Accidental release and disposal also led to contamination of groundwater at many locations, however, and this legacy persists. Although very stable, CFCs may degrade via abiotic and biotic pathways. Quantification of the degree of transformation of CFCs has been challenging due to other processes such as dilution, sorption and volatilization. Compound specific stable carbon isotope analysis (CSIA) has been successfully applied for a variety of priority pollutants to distinguish degradation from other processes and to quantify transformation rates. A Purge & Trap - CSIA method developed in our lab was applied to determine the stable carbon isotopic signature of CFCs and HCFCs (hydrochlorofluorocarbons) in groundwater samples from a contaminated site. Preliminary results suggest that degradation of CFCs and HCFCs may result in enriched δ13C values, consistent with fractionation during bond breakage as has been reported for many other hydrocarbon pollutants. The effect of volatile loss during sampling on the isotopic signatures of CFCs was examined in laboratory experiments. Volatilization from pure phase CFCs showed a small inverse isotope effect during open system volatilization, opposite to the normal isotope effect generally observed during biodegradation. For volatilization of CFCs dissolved in water a much smaller isotope effect was observed. An important result from this work is that any volatile loss may introduce only a small change in CFC isotopic signatures in groundwater, and importantly, due to the opposite direction of isotope effects associated with volatilization versus degradation, any effects of volatile loss on the isotopic signatures cannot be confused with transformation of CFCs. At most, volatilization might contribute to a conservative estimate of the extent of degradation.

Emissions of polycyclic aromatic hydrocarbons (PAH) from open burning of biomass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jenkins, B.M.

Emissions of polycyclic aromatic hydrocarbons (PAH) were measured during wind tunnel simulations of open burning for various types of biomass. The wind tunnel (Jenkins, et al., 1993) was used to simulate open fires spreading in opposition to the wind for cereal crop residues, and pile fires in agricultural and sylvicultural wood residues. Emission factors expressing the mass of pollutant species emitted per unit mass of dry fuel consumed were derived from mass balances conducted on each fire. Emission factors for primary pollutants and volatile organic species were similarly derived. Partitioning of PAH in the combustion products was investigated by determiningmore » mass fractions on particulate matter and in a downstream resin trap and other sampling train components. Yields of PAH are given for the major types of fuels and burning conditions.« less

Ozone Modulation/Membrane Introduction Mass Spectrometry for Analysis of Hydrocarbon Pollutants in Air

NASA Astrophysics Data System (ADS)

Atkinson, D. B.

2001-12-01

Modulation of volatile hydrocarbons in two-component mixtures is demonstrated using an ozonolysis pretreatment with membrane introduction mass spectrometry (MIMS). The MIMS technique allows selective introduction of volatile and semivolatile analytes into a mass spectrometer via processes known collectively as pervaporation [Kotiaho and Cooks, 1992]. A semipermeable polymer membrane acts as an interface between the sample (vapor or solution) and the vacuum of the mass spectrometer. This technique has been demonstrated to allow for sensitive analysis of hydrocarbons and other non-polar volatile organic compounds (VOC`s) in air samples[Cisper et al., 1995] . The methodology has the advantages of no sample pretreatment and short analysis time, which are promising for online monitoring applications but the chief disadvantage of lack of a separation step for the different analytes in a mixture. Several approaches have been investigated to overcome this problem including use of selective chemical ionization [Bier and Cooks, 1987] and multivariate calibration techniques[Ketola et al., 1999] . A new approach is reported for the quantitative measurement of VOCs in complex matrices. The method seeks to reduce the complexity of mass spectra observed in hydrocarbon mixture analysis by selective pretreatment of the analyte mixture. In the current investigation, the rapid reaction of ozone with alkenes is used, producing oxygenated compounds which are suppressed by the MIMS system. This has the effect of removing signals due to unsaturated analytes from the compound mass spectra, and comparison of the spectra before and after the ozone treatment reveals the nature of the parent compounds. In preliminary investigations, ozone reacted completely with cyclohexene from a mixture of cylohexene and cyclohexane, and with β -pinene from a mixture of toluene and β -pinene, suppressing the ion signals from the olefins. A slight attenuation of the cyclohexane and toluene in those mixtures was also observed. Despite this problem, the hydrocarbon signal response can be calibrated and the method can be used for quantitative analysis of volatile hydrocarbon compounds in air samples. This methodology should augment the efficiency of the MIMS approach in online and onsite monitoring of VOC emissions. Bier, M.R., and R.G. Cooks, Membrane Interface for Selective Introduction of Volatile Compounds Directly into The Ionization Chamber of a Mass Spectrometer, Anal. Chem., 59 (4), 597, 1987. Cisper, M.E., C.G. Gill, L.E. Townsend, and P.H. Hemberger, On-Line Detection of Volatile Organic Compounds in Air at Parts-per-Trillion Levels by Membrane Introduction Mass Spectrometry, Anal. Chem., 67 (8), 1413-1417, 1995. Ketola, R.A., M. Ojala, and J. Heikkonen, A Non-linear Asymmetric Error Function-based Least Mean Square Approach for the Analysis of Multicomponent Mass Spectra Measured by Membrane Inlet Mass Spectrometry, Rapid Commun. Mass Spectrom., 13 (8), 654, 1999. Kotiaho, T., and R.G. Cooks, Membrane Introduction Mass Spectrometry in Environmental Analysis, in: J.J. Breen, M. J. Dellarco, (Eds), Pollution in Industrial processes, 126 pp., ACS Symp. Ser., Washington, D.C. 508, 1992.

Toxic Remediation System And Method

DOEpatents

Matthews, Stephen M.; Schonberg, Russell G.; Fadness, David R.

1996-07-23

What is disclosed is a novel toxic waste remediation system designed to provide on-site destruction of a wide variety of hazardous organic volatile hydrocarbons, including but not limited to halogenated and aromatic hydrocarbons in the vapor phase. This invention utilizes a detoxification plenum and radiation treatment which transforms hazardous organic compounds into non-hazardous substances.

Evaluation of quicklime mixing for the remediation of petroleum contaminated soils.

PubMed

Schifano, V; Macleod, C; Hadlow, N; Dudeney, R

2007-03-15

Quicklime mixing is an established solidification/stabilization technique to improve mechanical properties and immobilise contaminants in soils. This study examined the effects of quicklime mixing on the concentrations and leachability of petroleum hydrocarbon compounds, in two natural soils and on a number of artificial sand/kaolinite mixtures. Several independent variables, such as clay content, moisture content and quicklime content were considered in the study. After mixing the soils with the quicklime, pH, temperature, moisture content, Atterberg limits and concentrations of petroleum hydrocarbon compounds were determined on soil and leachate samples extracted from the treated soils. Significant decreases in concentrations of petroleum hydrocarbon compounds were measured in soils and leachates upon quicklime mixing, which may be explained by a number of mechanisms such as volatilization, degradation and encapsulation of the hydrocarbon compounds promoted by the quicklime mixing. The increase in temperature due to the exothermic hydration reaction of quicklime when in contact with porewater helps to volatilize the light compounds but may not be entirely responsible for their concentration decreases and for the decrease of heavy aliphatics and aromatics concentrations.

Emissions of organic compounds from produced water ponds I: Characteristics and speciation.

PubMed

Lyman, Seth N; Mansfield, Marc L; Tran, Huy N Q; Evans, Jordan D; Jones, Colleen; O'Neil, Trevor; Bowers, Ric; Smith, Ann; Keslar, Cara

2018-04-01

We measured fluxes of methane, a suite of non-methane hydrocarbons (C2-C11), light alcohols, and carbon dioxide from oil and gas produced water storage and disposal ponds in Utah (Uinta Basin) and Wyoming (Upper Green River Basin) United States during 2013-2016. In this paper, we discuss the characteristics of produced water composition and air-water fluxes, with a focus on flux chamber measurements. In companion papers, we will (1) report on inverse modeling methods used to estimate emissions from produced water ponds, including comparisons with flux chamber measurements, and (2) discuss the development of mass transfer coefficients to estimate emissions and place emissions from produced water ponds in the context of all regional oil and gas-related emissions. Alcohols (made up mostly of methanol) were the most abundant organic compound group in produced water (91% of total volatile organic concentration, with upper and lower 95% confidence levels of 89 and 93%) but accounted for only 34% (28 to 41%) of total organic compound fluxes from produced water ponds. Non-methane hydrocarbons, which are much less water-soluble than methanol and less abundant in produced water, accounted for the majority of emitted organics. C6-C9 alkanes and aromatics dominated hydrocarbon fluxes, perhaps because lighter hydrocarbons had already volatilized from produced water prior to its arrival in storage or disposal ponds, while heavier hydrocarbons are less water soluble and less volatile. Fluxes of formaldehyde and other carbonyls were low (1% (1 to 2%) of total organic compound flux). The speciation and magnitude of fluxes varied strongly across the facilities measured and with the amount of time water had been exposed to the atmosphere. The presence or absence of ice also impacted fluxes. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of a cationic surfactant on the volatilization of PAHs from soil.

PubMed

Lu, Li; Zhu, Lizhong

2012-06-01

Cationic surfactants are common in soils because of their use in daily cosmetic and cleaning products, and their use as a soil amendment for the mitigation and remediation of organic contaminated soils has been proposed. Such surfactant may affect the transfer and fate of organic contaminants in the environment. This study investigated the effect of a cationic surfactant, dodecylpyridinium bromide (DDPB), on the volatilization of polycyclic aromatic hydrocarbons (PAHs) from a paddy soil. The volatilization of PAHs from moist soil amended with different concentrations of DDPB was tested in an open system. The specific effects of DDPB on the liquid-vapor and solid-vapor equilibriums of PAHs were separately investigated in closed systems by headspace analysis. DDPB affects both liquid-vapor and solid-vapor processes of PAHs in soil. At DDPB concentrations below the critical micelle concentration (CMC), movement of PAHs from the bulk solution to the gas-liquid interface appeared to be facilitated by interaction between PAHs and the surfactant monomers adsorbed at the gas-liquid interface, promoting the volatilization of PAHs from solution. However, when DDPB was greater than the CMC, volatilization was inhibited due to the solubilization of PAHs by micelles. On the other hand, the formation of sorbed surfactant significantly inhibited the solid-vapor volatilization of PAHs. The overall effect of the two simultaneous effects of DDPB on liquid-vapor and solid-vapor processes was a decreased volatilization loss of PAHs from soil. Inhibition of PAH volatilization was more significant for the soil with a lower moisture content.

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

PubMed

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

2015-12-01

The effect of muscle type on volatile compounds throughout the manufacture of Celta dry-cured ham was studied. Thirty Celta ham were taken from the fresh pieces, after the end of the salting stage, after 120 days of post-salting, after the end of drying-ripening stage, and after 165 and 330 days of "bodega" step. The volatile compounds from semimembranosus (SM) and biceps femoris (BF) muscles were extracted by using headspace-solid phase microextraction (SPME) and analysed by gas chromatographic/mass spectrometry (GC/MS). Fifty-five volatile compounds were identified and quantified. The number of volatile compounds increased during the different steps of the process, reaching at 550 days of process 39 and 40 volatile compounds in SM and BF muscles, respectively. Results indicated that the most abundant chemical family in flavour at the end of the manufacturing process were esters in the two muscles studied, followed by aliphatic hydrocarbons and aldehydes. During the manufacturing process, an increase in the total amount of volatile compounds was observed, being this increase more marked in samples from BF muscle (from 550.7 to 1118.9 × 10(6) area units) than in samples from SM muscle (from 459.3 to 760.4 × 10(6) area units). Finally, muscle type displayed significant (P < 0.05) differences for four esters, two alcohols, one aldehyde, one ketone and four aliphatic hydrocarbons. © The Author(s) 2014.

Emissions of Volatile Organic Compounds from Oil and Gas Operations in Northeastern Oklahoma - Wintertime Ambient Air Studies from Three Consecutive Years

NASA Astrophysics Data System (ADS)

Ghosh, B.

2017-12-01

Volatile organic compounds (VOCs) are emitted into the atmosphere from a variety of sources including oil and gas (O&G) operations, vehicle exhausts, industrial processes, and biogenic sources. Understanding of emission sources and their air quality impact is crucial for effective environmental policymaking and its implementation. Three consecutive wintertime campaigns to study ambient air were conducted in Northeastern Oklahoma during February-March of 2015, 2016, and 2017. The goals of these campaigns were to study ambient VOCs in the region, estimate their air quality impact, and understand how the impact changes over a span of three years. This presentation highlights results from the 2017 campaign. In-situ measurements of methane, ethane, and CO were conducted by an Aerodyne Dual QCL Analyzer while ozone and NOx were measured using Teledyne monitors. In addition, 392 whole air samples were collected and non-methane hydrocarbons (NMHCs) in the samples were analyzed using GC-MS (Agilent). High levels of methane (> 8 ppm) were observed during the study. Correlation with ethane indicated that methane primarily originated from O&G operations with little biogenic contributions. Among NMHCs, C2-C5 alkanes were the most dominant with mean mixing ratios ranging from 0.9 to 6.8 ppb. Chemical tracers (propane, ethyne, CO) and isomeric ratios (iC5/nC5, Figure 1) identified oil and gas activity as the primary source of NMHCs. Photochemical age was calculated to estimate emission source composition. Ozone showed strong diurnal variation characteristic of photochemical production with a maximum mixing ratio of 58 ppb. The results from the 2017 study will be compared with results from studies in 20151 and 20162 and their significance on local air quality will be discussed. References Ghosh, B.; Volatile Organic Compound Emissions from Oil and Gas Production Sources: A Pilot Study in Northeastern Oklahoma; Poster presentation at AGU Fall Meeting; 2015; A11M-0249; (Link) Ghosh, B.; Hydrocarbon Emission from Oil and Gas Production Activity in Northeastern Oklahoma - Wintertime Measurements in 2015 and 2016; Oral Presentation at AGU Fall Meeting; 2016; A14A-08; (Link)

Impact of VOC removal by activated carbon on biodegradation rates of diesel, Syntroleum and biodiesel in contaminated sand.

PubMed

Horel, Agota; Schiewer, Silke

2016-12-15

The degradation of conventional diesel (D), synthetic diesel (Syntroleum), and pure fish biodiesel (B100) by indigenous microbes was investigated in laboratory microcosms containing contaminated sand. The fate of volatiles and the influence of volatilization on degradation rates were examined by placing activated carbon (AC) in microcosm headspaces to sorb volatiles. Three AC regimes were compared: no activated carbon (NAC), regular weekly AC change (RAC), and frequent AC change (FAC), where the frequency of activated carbon exchange declined from daily to weekly. Generally, the alternative fuels were biodegraded faster than diesel fuel. Hydrocarbon mineralization percentages for the different fuel types over 28days were between 23% (D) and 48% (B100) in the absence of activated carbon, decreased to 12% (D) - 37% (B100) with weekly AC exchange, and were further reduced to 9-22% for more frequent AC change. Sorption of volatiles to AC lowered their availability as a substrate for microbes, reducing respiration. Volatilization was negligible for the biodiesel. A mass balance for the carbon initially present as hydrocarbons in microcosms with activated carbon in the head space was on average 92% closed, with 45-70% remaining in the soil after 4weeks, 9-37% mineralized and up to 12% volatilized. Based on nutrient consumption, up to 29% of the contaminants were likely converted into biomass. Copyright © 2016 Elsevier B.V. All rights reserved.

Petrographic and Vitrinite Reflectance Analyses of a Suite of High Volatile Bituminous Coal Samples from the United States and Venezuela

USGS Publications Warehouse

Hackley, Paul C.; Kolak, Jonathan J.

2008-01-01

This report presents vitrinite reflectance and detailed organic composition data for nine high volatile bituminous coal samples. These samples were selected to provide a single, internally consistent set of reflectance and composition analyses to facilitate the study of linkages among coal composition, bitumen generation during thermal maturation, and geochemical characteristics of generated hydrocarbons. Understanding these linkages is important for addressing several issues, including: the role of coal as a source rock within a petroleum system, the potential for conversion of coal resources to liquid hydrocarbon fuels, and the interactions between coal and carbon dioxide during enhanced coalbed methane recovery and(or) carbon dioxide sequestration in coal beds.

Essential Oils’ Chemical Characterization and Investigation of Some Biological Activities: A Critical Review

PubMed Central

Dhifi, Wissal; Bellili, Sana; Jazi, Sabrine; Bahloul, Nada; Mnif, Wissem

2016-01-01

This review covers literature data summarizing, on one hand, the chemistry of essential oils and, on the other hand, their most important activities. Essential oils, which are complex mixtures of volatile compounds particularly abundant in aromatic plants, are mainly composed of terpenes biogenerated by the mevalonate pathway. These volatile molecules include monoterpenes (hydrocarbon and oxygenated monoterpens), and also sesquiterpenes (hydrocarbon and oxygenated sesquiterpens). Furthermore, they contain phenolic compounds, which are derived via the shikimate pathway. Thanks to their chemical composition, essential oils possess numerous biological activities (antioxidant, anti-inflammatory, antimicrobial, etc…) of great interest in food and cosmetic industries, as well as in the human health field. PMID:28930135

Mineral-assisted production of benzene under hydrothermal conditions: Insights from experimental studies on C6 cyclic hydrocarbons

NASA Astrophysics Data System (ADS)

Venturi, Stefania; Tassi, Franco; Gould, Ian R.; Shock, Everett L.; Hartnett, Hilairy E.; Lorance, Edward D.; Bockisch, Christiana; Fecteau, Kristopher M.; Capecchiacci, Francesco; Vaselli, Orlando

2017-10-01

Volatile Organic Compounds (VOCs) are ubiquitously present at low but detectable concentrations in hydrothermal fluids from volcanic and geothermal systems. Although their behavior is strictly controlled by physical and chemical parameters, the mechanisms responsible for the production of most VOCs in natural environments are poorly understood. Among them, benzene, whose abundances were found to be relatively high in hydrothermal gases, can theoretically be originated from reversible catalytic reforming processes, i.e. multi-step dehydrogenation reactions, involving saturated hydrocarbons. However, this hypothesis and other hypotheses are difficult to definitively prove on the basis of compositional data obtained by natural gas discharges only. In this study, therefore, laboratory experiments were carried out to investigate the production of benzene from cyclic hydrocarbons at hydrothermal conditions, specifically 300 °C and 85 bar. The results of experiments carried out in the presence of water and selected powdered minerals, suggest that cyclohexane undergoes dehydrogenation to form benzene, with cyclohexene and cyclohexadiene as by-products, and also as likely reaction intermediates. This reaction is slow when carried out in water alone and competes with isomerization and hydration pathways. However, benzene formation was increased compared to these competing reactions in the presence of sulfide (sphalerite and pyrite) and iron oxide (magnetite and hematite) minerals, whereas no enhancement of any reaction products was observed in the presence of quartz. The production of thiols was observed in experiments involving sphalerite and pyrite, suggesting that sulfide minerals may act both to enhance reactivity and also as reactants after dissolution. These experiments demonstrate that benzene can be effectively produced at hydrothermal conditions through dehydrogenation of saturated cyclic organic structures and highlight the crucial role played by minerals in this process.

A Study of the Nephrotoxicity and Metabolism of Tetralin and Indan in Fischer 344 Rats

DTIC Science & Technology

1989-05-01

5, a jet fuel composed of aliphatic and aromatic hydrocarbons with the majority of the straight-chain hydrocarbons being between C10 and C15...hydrocarbon of intermediate boiling point and volatility and is similar to the civilian jet fuel , A-1. DFM is a mixture of long chain aliphatic...to compliment earlier research on jet fuel , JP-10, cis- and trans- decalin, and tetralin, it was anticipated some enlightenment could be obtained on

A Study of the Nephrotoxicity and Metabolism of Tetralin and Indan in Fischer 344 Rats.

DTIC Science & Technology

1988-02-08

evaluated petroleum and shale-derived JP-5, a jet fuel composed of aliphatic and aromatic hydrocarbons with the majority of the straight-chain hydrocarbons...much like gasoline. JP-8 is a mixture of hydrocarbon of intermediate boiling point and volatility and is similar to the civilian jet fuel , A-1. DFM is a...conventional versus shale-derived JP-5 jet fuel : Light microscopy, hematologic, and serum chemistry studies. Toxicol Appl Pharmacol, 57, 302-317 (1981

Synthesis of hydrocarbons by CO2 fluid conversion with hydrogen: Experimental modeling at 7.8 GPa and 1350°C

NASA Astrophysics Data System (ADS)

Sokol, A. G.; Tomilenko, A. A.; Bul'bak, T. A.; Sobolev, N. V.

2017-12-01

Synthesis of hydrocarbons by the interaction of a CO2 fluid with hydrogen mantle domains has been simulated in an experiment at 7.8 GPa and 1350°C. The synthesized fluid contains mainly aldehydes; lower amounts of ketones, alcohols, esters, and ethers; as well as noticeable amounts of isobutane and butane, alkenes, arenes, and polycyclic aromatic and heterocyclic hydrocarbons. The fluid is compositionally close to volatiles found in inclusions from mantle olivines and picroilmenites.

Determination of the volatile and semi-volatile secondary metabolites, and aristolochic acids in Aristolochia ringens Vahl.

PubMed

Stashenko, Elena E; Andrés Ordóñez, Sergio; Marín, Néstor Armando; Martínez, Jairo René

2009-10-01

Volatile and semi-volatile secondary metabolites, as well as aristolochic acids (AA), present in leaves, stems, and flowers of Aristolochia ringens were determined by gas chromatography (GC)-mass spectrometry (MS) and high-performance liquid chromatography (HPLC) methods, respectively. Metabolite isolation was performed using different extraction techniques: microwave-assisted hydrodistillation (MWHD), supercritical fluid extraction, and headspace solid-phase microextraction (HS-SPME). The chemical composition of the extracts and oils was established by GC-MS. The determinations of AAI and AAII were conducted by methanolic extraction of different plant parts followed by HPLC analysis. Essential oil yields from leaves and stems were 0.008 +/- 0.0022% and 0.047 +/- 0.0026%, respectively. Aristolochia ringens flowers did not yield essential oil under MWHD. Sesquiterpene hydrocarbons (66%) were the main compounds in the essential oil isolated from leaves whereas monoterpene hydrocarbons (73%) predominated in the stems essential oil. Yields of extracts isolated by SFE from leaves, stems, and flowers were 4 +/- 1.8%, 1.2 +/- 0.25%, and 4 +/- 1.8%, respectively. In vivo HS-SPME of flowers isolated compounds with known unpleasant smells such as volatile aldehydes and short-chain carboxylic acids. HPLC analysis detected the presence of AAII in the flowers of Aristolochia ringens at a concentration of 610 +/- 47 mg/kg of dried flower.

Cost Effective, Ultra Sensitive Groundwater Monitoring for Site Remediation and Management

DTIC Science & Technology

2015-05-01

feasibility studies. ................... 30  Table 5. Compounds screened in the laboratory for IS2 sampling...tank SVOC semivolatile organic compound TCE trichloroethene TPH total petroleum hydrocarbon USEPA U.S. Environmental Protection Agency UST...underground storage tank V volt VOA volatile organic analysis VOC volatile organic compound Technical material contained in this report has

Evaluation of volatile organic emissions from hazardous waste incinerators.

PubMed Central

Sedman, R M; Esparza, J R

1991-01-01

Conventional methods of risk assessment typically employed to evaluate the impact of hazardous waste incinerators on public health must rely on somewhat speculative emissions estimates or on complicated and expensive sampling and analytical methods. The limited amount of toxicological information concerning many of the compounds detected in stack emissions also complicates the evaluation of the public health impacts of these facilities. An alternative approach aimed at evaluating the public health impacts associated with volatile organic stack emissions is presented that relies on a screening criterion to evaluate total stack hydrocarbon emissions. If the concentration of hydrocarbons in ambient air is below the screening criterion, volatile emissions from the incinerator are judged not to pose a significant threat to public health. Both the screening criterion and a conventional method of risk assessment were employed to evaluate the emissions from 20 incinerators. Use of the screening criterion always yielded a substantially greater estimate of risk than that derived by the conventional method. Since the use of the screening criterion always yielded estimates of risk that were greater than that determined by conventional methods and measuring total hydrocarbon emissions is a relatively simple analytical procedure, the use of the screening criterion would appear to facilitate the evaluation of operating hazardous waste incinerators. PMID:1954928

Kinetic and molecular analyses reveal isoprene degradation potential of Methylobacterium sp.

PubMed

Srivastva, Navnita; Vishwakarma, P; Bhardwaj, Y; Singh, A; Manjunath, K; Dubey, Suresh K

2017-10-01

Efforts were made to isolate and characterize bacteria capable of growing on methane and organic compounds, and to achieve the simultaneous degradation of more than one pollutant. Among the methanotrophs, species of Methylobacterium was able to catabolize a variety of hydrocarbons, including the branched-chain alkenes. Therefore, laboratory incubations experiments were carried out in batch mode to assess the potential of Methylobacterium sp. PV1 for degrading isoprene, the low-molecular-weight alkene, the most abundant non-methane volatile hydrocarbon present in the environment. Methylobacterium sp. PV1, isolated from paddy field soil, was characterized by pmoA and 16S rRNA gene sequencing and FAME analysis, and used for isoprene degradation. The kinetics of biodegradation is studied using the Michaelis-Menten model. The optimum degradation (80%) with maximum average relative degradation rate was observed at 150ppm isoprene. The degradation products were also analyzed using FTIR. Copyright © 2017 Elsevier Ltd. All rights reserved.

Volatile-rich lunar soil - Evidence of possible cometary impact.

NASA Technical Reports Server (NTRS)

Gibson, E. K., Jr.; Moore, G. W.

1973-01-01

A subsurface Apollo 16 soil, 61221, is much richer in volatile compounds than soils from any other locations or sites as shown by thermal analysis-gas release measurements. A weight loss of 0.03% during the interval 175 to 350 C was associated with the release of water, carbon dioxide, methane, hydrogen cyanide, hydrogen, and minor amounts of hydrocarbons and other species. These volatile components may have been brought to this site by a comet, which may have formed North Ray crater.

Studies of volatiles and organic materials in early terrestrial and present-day outer solar system environments

NASA Technical Reports Server (NTRS)

Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.

1991-01-01

A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.

Chemical recycling of carbon dioxide to methanol and dimethyl ether: from greenhouse gas to renewable, environmentally carbon neutral fuels and synthetic hydrocarbons.

PubMed

Olah, George A; Goeppert, Alain; Prakash, G K Surya

2009-01-16

Nature's photosynthesis uses the sun's energy with chlorophyll in plants as a catalyst to recycle carbon dioxide and water into new plant life. Only given sufficient geological time can new fossil fuels be formed naturally. In contrast, chemical recycling of carbon dioxide from natural and industrial sources as well as varied human activities or even from the air itself to methanol or dimethyl ether (DME) and their varied products can be achieved via its capture and subsequent reductive hydrogenative conversion. The present Perspective reviews this new approach and our research in the field over the last 15 years. Carbon recycling represents a significant aspect of our proposed Methanol Economy. Any available energy source (alternative energies such as solar, wind, geothermal, and atomic energy) can be used for the production of needed hydrogen and chemical conversion of CO(2). Improved new methods for the efficient reductive conversion of CO(2) to methanol and/or DME that we have developed include bireforming with methane and ways of catalytic or electrochemical conversions. Liquid methanol is preferable to highly volatile and potentially explosive hydrogen for energy storage and transportation. Together with the derived DME, they are excellent transportation fuels for internal combustion engines (ICE) and fuel cells as well as convenient starting materials for synthetic hydrocarbons and their varied products. Carbon dioxide thus can be chemically transformed from a detrimental greenhouse gas causing global warming into a valuable, renewable and inexhaustible carbon source of the future allowing environmentally neutral use of carbon fuels and derived hydrocarbon products.

Determination of volatile chlorinated hydrocarbons in water samples by static headspace gas chromatography with electron capture detection.

PubMed

Li, Tiejun; Guo, Yuanming; Hu, Hongmei; Zhang, Xiaoning; Jin, Yanjian; Zhang, Xiaojun; Zhang, Yurong

2016-01-01

A simple, efficient, solvent-free, and commercial readily available approach for determination of five volatile chlorinated hydrocarbons in water samples using the static headspace sampling and gas chromatography with electron capture detection has been described. The proposed static headspace sampling method was initially optimized and the optimum experimental conditions found were 10 mL water sample containing 20% w/v sodium chloride placed in a 20 mL vial and stirred at 50ºC for 20 min. The linearity of the method was in the range of 1.2-240 μg/L for dichloromethane, 0.2-40 μg/L for trichloromethane, 0.005-1 μg/L for perchloromethane, 0.025-5 μg/L for trichloroethylene, and 0.01-2 μg/L for perchloroethylene, with coefficients of determination ranging between 0.9979 and 0.9990. The limits of detection were in the low μg/L level, ranging between 0.001 and 0.3 μg/L. The relative recoveries of spiked five volatile chlorinated hydrocarbons with external calibration method at different concentration levels in pure, tap, sea water of Jiaojiang Estuary, and sea water of waters of Xiaomendao were in the range of 91-116, 96-105, 86-112, and 80-111%, respectively, and with relative standard deviations of 1.9-3.6, 2.3-3.5, 1.5-2.7, and 2.3-3.7% (n = 5), respectively. The performance of the proposed method was compared with traditional liquid-liquid extraction on the real water samples (i.e., pure, tap, and sea water, etc.) and comparable efficiencies were obtained. It is concluded that this method can be successfully applied for the determination of volatile chlorinated hydrocarbons in different water samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid discovery and functional characterization of terpene synthases from four endophytic xylariaceae

DOE PAGES

Wu, Weihua; Tran, William; Taatjes, Craig A.; ...

2016-02-17

Endophytic fungi are ubiquitous plant endosymbionts that establish complex and poorly understood relationships with their host organisms. Many endophytic fungi are known to produce a wide spectrum of volatile organic compounds (VOCs) with potential energy applications, which have been described as "mycodiesel". Many of these mycodiesel hydrocarbons are terpenes, a chemically diverse class of compounds produced by many plants, fungi, and bacteria. Due to their high energy densities, terpenes, such as pinene and bisabolene, are actively being investigated as potential "drop-in" biofuels for replacing diesel and aviation fuel. In this study, we rapidly discovered and characterized 26 terpene synthases (TPSs)more » derived from four endophytic fungi known to produce mycodiesel hydrocarbons. The TPS genes were expressed in an E. coli strain harboring a heterologous mevalonate pathway designed to enhance terpene production, and their product profiles were determined using Solid Phase Micro-Extraction (SPME) and GC-MS. Lastly, out of the 26 TPS’s profiled, 12 TPS’s were functional, with the majority of them exhibiting both monoterpene and sesquiterpene synthase activity.« less

Rapid discovery and functional characterization of terpene synthases from four endophytic xylariaceae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Weihua; Tran, William; Taatjes, Craig A.

Endophytic fungi are ubiquitous plant endosymbionts that establish complex and poorly understood relationships with their host organisms. Many endophytic fungi are known to produce a wide spectrum of volatile organic compounds (VOCs) with potential energy applications, which have been described as "mycodiesel". Many of these mycodiesel hydrocarbons are terpenes, a chemically diverse class of compounds produced by many plants, fungi, and bacteria. Due to their high energy densities, terpenes, such as pinene and bisabolene, are actively being investigated as potential "drop-in" biofuels for replacing diesel and aviation fuel. In this study, we rapidly discovered and characterized 26 terpene synthases (TPSs)more » derived from four endophytic fungi known to produce mycodiesel hydrocarbons. The TPS genes were expressed in an E. coli strain harboring a heterologous mevalonate pathway designed to enhance terpene production, and their product profiles were determined using Solid Phase Micro-Extraction (SPME) and GC-MS. Lastly, out of the 26 TPS’s profiled, 12 TPS’s were functional, with the majority of them exhibiting both monoterpene and sesquiterpene synthase activity.« less

Volatile organic compounds in Gulf of Mexico sediments

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, T.J.

1988-01-01

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

Improving the conversion of biomass in catalytic fast pyrolysis via white-rot fungal pretreatment.

PubMed

Yu, Yanqing; Zeng, Yelin; Zuo, Jiane; Ma, Fuying; Yang, Xuewei; Zhang, Xiaoyu; Wang, Yujue

2013-04-01

This study investigated the effect of white-rot fungal pretreatment on corn stover conversion in catalytic fast pyrolysis (CFP). Corn stover pretreated by white-rot fungus Irpex lacteus CD2 was fast pyrolyzed alone (non-CFP) and with ZSM-5 zeolite (CFP) in a semi-batch pyroprobe reactor. The fungal pretreatment considerably increased the volatile product yields (predominantly oxygenated compounds) in non-CFP, indicating that fungal pretreatment enhances the corn stover conversion in fast pyrolysis. In the presence of ZSM-5 zeolite, these oxygenated volatiles were further catalytically converted to aromatic hydrocarbons, whose yield increased from 10.03 wt.% for the untreated corn stover to 11.49 wt.% for the pretreated sample. In contrast, the coke yield decreased from 14.29 to 11.93 wt.% in CFP following the fungal pretreatment. These results indicate that fungal pretreatment can enhance the production of valuable aromatics and decrease the amount of undesired coke, and thus has a beneficial effect on biomass conversion in CFP. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cost-Effective, Ultra-Sensitive Groundwater Monitoring for Site Remediation and Management

DTIC Science & Technology

2015-05-01

Example anion concentrations in groundwater used for feasibility studies. ................... 30 Table 5. Compounds screened in the laboratory for IS2...phase extraction ST storage tank SVOC semivolatile organic compound TCE trichloroethene TPH total petroleum hydrocarbon USEPA U.S. Environmental...Protection Agency UST underground storage tank V volt VOA volatile organic analysis VOC volatile organic compound Technical material

Olfaction in the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae): Electroantennogram studies.

PubMed

Dickens, J C

1984-12-01

Electroantennogram (EAG) techniques were utilized to measure the antennal olfactory responsiveness of adult boll weevils,Anthonomus grandis Boh. (Coleoptera: Curculionidae), to 38 odorants, including both insect and host plant (Gossypium hirsutum L.) volatiles. EAGs of both sexes were indicative of at least two receptor populations: one receptor population primarily responsive to pheromone components and related compounds, the other receptor population primarily responsive to plant odors. Similar responses to male aggregation pheromone components (i.e., compounds I, II, and III + IV) were obtained from both sexes, but females were slightly more sensitive to I. Both sexes were highly responsive to components of the "green leaf volatile complex," especially the six-carbon saturated and monounsaturated primary alcohols. Heptanal was the most active aldehyde tested. More acceptors responded to oxygenated monoterpenes than to monoterpene hydrocarbons. β-Bisabolol, the major volatile of cotton, was the most active sesquiterpene. In general, males, which are responsible for host selection and pheromone production, were more sensitive to plant odors than were females. In fact, males were as sensitive to β-bisabolol and heptanal as to aggregation pheromone components. Electrophysiological data are discussed with regard to the role of insect and host plant volatiles in host selection and aggregation behavior of the boll weevil.

Hydrocarbon source potential and maturation in eocene New Zealand vitrinite-rich coals: Insights from traditional coal analyses, and Rock-Eval and biomarker studies

USGS Publications Warehouse

Newman, J.; Price, L.C.; Johnston, J.H.

1997-01-01

The results of traditional methods of coal characterisation (proximate, specific energy, and ultimate analyses) for 28 Eocene coal samples from the West Coast of New Zealand correspond well with biomarker ratios and Rock-Eval analyses. Isorank variations in vitrinite fluorescence and reflectance recorded for these samples are closely related to their volatile-matter content, and therefore indicate that the original vitrinite chemistry is a key controlling factor. By contrast, the mineral-matter content and the proportion of coal macerals present appear to have had only a minor influence on the coal samples' properties. Our analyses indicate that a number of triterpane biomarker ratios show peak maturities by high volatile bituminous A rank; apparent maturities are then reversed and decline at the higher medium volatile bituminous rank. The Rock-Eval S1 +S2 yield also maximizes by high volatile bituminous A rank, and then declines; however, this decline is retarded in samples with the most hydrogen-rich (perhydrous) vitrinites. These Rock-Eval and biomarker trends, as well as trends in traditional coal analyses, are used to define the rank at which expulsion of gas and oil occurs from the majority of the coals. This expulsion commences at high volatile A bituminous rank, and persists up to the threshold of medium volatile bituminous rank (c. 1.1% Ro ran. or 1.2% Ro max in this sample set), where marked hydrocarbon expulsion from perhydrous vitrinites begins to take place.

Photo-assisted removal of fuel oil hydrocarbons from wood and concrete.

PubMed

Popova, Inna E; Kozliak, Evguenii I

2008-08-01

A novel photo-treatment to decontaminate building structural elements polluted with fuel oil hydrocarbons as a result of spillage and/or a catastrophic flood was examined. A proof-of-concept study evaluating the photocatalytic removal of hydrocarbons (n-hexadecane and fuel oil #2) from contaminated wood (southern yellow pine) and concrete was conducted using scintillation counting (with (14)C-labeled n-hexadecane) and gas chromatography. Contaminated samples were irradiated by UV or fluorescent light in the absence or presence of a photocatalyst, TiO(2). As a result of the treatment, under various scenarios, up to 80-98% of the originally applied n-hexadecane was removed, within a wide range of contaminant concentrations (4-250 mg/g wood). The essential treatment time increased from 1-7 days for low concentrations to several weeks for high concentrations. Mass balance experiments showed that the only product formed from (14)C-labeled n-hexadecane in detectable amounts was (14)CO(2). For low amounts of applied hydrocarbon (4-20 mg/g wood), the overall process rate was limited by the contaminant transport/mobility whereas for high n-hexadecane concentrations (150-250 mg/g, corresponding to 50-80% filling of wood pores), the key factor was the photochemical reaction. Photodegradation experiments conducted with standard heating fuel oil #2 (a representative real-world contaminant) resulted in a significant (up to 80%) photochemical removal of mid-size hydrocarbons (C(13)-C(17)) in 3 weeks whereas heavier hydrocarbons (> C(17)) were not affected; light hydrocarbons (< C(12)) were removed by evaporation. These results point toward a promising technique to reclaim wooden and concrete structures contaminated with semi-volatile chemicals.

Measurement of biogenic hydrocarbon emissions from vegetation in the Lower Fraser Valley, British Columbia

NASA Astrophysics Data System (ADS)

Drewitt, G. B.; Curren, K.; Steyn, D. G.; Gillespie, T. J.; Niki, H.

Biogenic volatile organic compounds (VOCs) participate in many chemical reactions in the atmosphere and in some cases, adversely affect air quality through increased production of photochemical ozone near urban sources of nitrogen oxides. In order to implement an effective control strategy, the relative role of these biogenic hydrocarbon emissions in producing ground-level ozone must be known. During the summers of 1995 and 1996, a field study was undertaken to determine fluxes of biogenic VOCs from both natural and agricultural surfaces in the Lower Fraser Valley located in southwestern British Columbia. Emissions from agricultural surfaces were measured using a flux gradient approach while emissions from the dominant tree species in the region were measured with a branch enclosure system. Results show very little biogenic VOC production from many agricultural crops such as pasture, Potatoes or Blueberries. Cranberries showed very high emissions during the summer of 1994 but failed to show similar results during the summer of 1995. Emissions of isoprene and monoterpenes from native tree species such as Western Red Cedar, Douglas Fir and Coastal Hemlock were quite low. Cottonwood trees on the other hand had fairly low emissions of monoterpenes but extremely high emissions of isoprene. Measurements provided here will be useful for improving our database of hydrocarbon emissions rates from vegetation for future emission inventories and model testing.

Aerial Surveys of Elevated Hydrocarbon Emissions from Oil and Gas Production Sites.

PubMed

Lyon, David R; Alvarez, Ramón A; Zavala-Araiza, Daniel; Brandt, Adam R; Jackson, Robert B; Hamburg, Steven P

2016-05-03

Oil and gas (O&G) well pads with high hydrocarbon emission rates may disproportionally contribute to total methane and volatile organic compound (VOC) emissions from the production sector. In turn, these emissions may be missing from most bottom-up emission inventories. We performed helicopter-based infrared camera surveys of more than 8000 O&G well pads in seven U.S. basins to assess the prevalence and distribution of high-emitting hydrocarbon sources (detection threshold ∼ 1-3 g s(-1)). The proportion of sites with such high-emitting sources was 4% nationally but ranged from 1% in the Powder River (Wyoming) to 14% in the Bakken (North Dakota). Emissions were observed three times more frequently at sites in the oil-producing Bakken and oil-producing regions of mixed basins (p < 0.0001, χ(2) test). However, statistical models using basin and well pad characteristics explained 14% or less of the variance in observed emission patterns, indicating that stochastic processes dominate the occurrence of high emissions at individual sites. Over 90% of almost 500 detected sources were from tank vents and hatches. Although tank emissions may be partially attributable to flash gas, observed frequencies in most basins exceed those expected if emissions were effectively captured and controlled, demonstrating that tank emission control systems commonly underperform. Tanks represent a key mitigation opportunity for reducing methane and VOC emissions.

Hydrocarbon Emission from Oil and Gas Production Activity in Northeastern Oklahoma - Wintertime Measurements in 2015 and 2016

NASA Astrophysics Data System (ADS)

Ghosh, B.

2016-12-01

Hydrocarbons can be emitted into the atmosphere from various sources and play a crucial role in local and regional air quality through formation of secondary pollutants such as ozone and particulate matter. Understanding their sources and their potential air quality impact is essential for effective environmental policymaking. A ground based ambient air measurement campaign was conducted in February-March of 2016 at the Phillips 66 Research Center in Northeastern Oklahoma to study ambient hydrocarbons in the region, understand their sources, as well as estimate their air quality impact. This study is a follow-up to a study conducted during the same time in 2015 and aims to understand the variation of hydrocarbons levels in ambient air over time and the corresponding air quality impact. Various trace gases were measured using a suite of instrumentation. Non-methane hydrocarbons (NMHCs) were sampled using two-hour time integrated whole air sampling. A total of 375 air samples were collected during the study and were analyzed offline with GC-MS (Agilent) following cold-trap dehydration (Entech Instruments). In addition, higher time resolution measurement of methane, ethane, CO, CO2, N2O, and H2O was achieved by a 1Hz Dual QCL Monitor (Aerodyne) along with a 0.1 Hz ozone monitor (2B Technologies). Levels of methane of 7 ppm and above were observed in this study. Among NMHCs, C2-C5 alkanes were the most dominant with their mean concentrations ranging from 1.9 to 17 ppb (Figure 1). Chemical tracers (ethane, propane, ethyne, CO) and isomeric ratios (i-C5/ n-C5) suggest that oil and gas production activity probably was the source of hydrocarbon emissions measured in this study. Photochemical age was determined using hydrocarbon ratios and its significance will be discussed. While the 2016 winter was warmer compared to 2015, overall levels of NMHCs are higher in 2016 compared to 2015 and have a different distribution in mixing ratios. The results from 2016 study will be compared with 2015 results.1Significance of these emissions on local air quality will also be discussed. Reference Buddhadeb Ghosh, Volatile Organic Compound Emissions from Oil and Gas Production Sources: A Pilot Study in Northeastern Oklahoma AGU Fall Meeting 2015, https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/59445

An improved light hydrocarbon analysis system. Interim report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamontagne, R.A.

1982-05-11

A system for extracting and measuring ambient levels of C1-C4 hydrocarbons and carbon monoxide (CO) in seawater is described. The analytical instrument is a gas chromatograph with flame ionization detectors that incorporates a catalytic conversion of CO to CH4 (methane). The samples are concentrated prior to introduction to the chromatographic system. The volatile hydrocarbons are extracted from the seawater by the use of a helium flow stream and concentrated on dry ice-acetone cold traps. Air samples can be processed in a similar way.

Production of methanol from heat-stressed pepper and corn leaf disks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, J.A.

Early Calwonder'' pepper (Capsicum annuum L.) and Jubilee'' corn (Zea mays L.) leaf disks exposed to high temperature stress produced ethylene, ethane, methanol, acetaldehyde, and ethanol based on comparison of retention times during gas chromatography to authentic standards. Methanol, ethanol, and acetaldehyde were also identified by mass spectroscopy. Corn leaf disks produced lower levels of ethylene, ethane, and methanol, but more acetaldehyde and ethanol than pepper. Production of ethane, a by-product of lipid peroxidation, coincided with an increase in electrolyte leakage (EL) in pepper but not in corn. Compared with controls, pepper leaf disks infiltrated with linolenic acid evolved significantlymore » greater amounts of ethane, acetaldehyde, and methanol and similar levels of ethanol. EL and volatile hydrocarbon production were not affected by fatty acid infiltration in corn. Infiltration of pepper leaves with buffers increasing in pH from 5.5 to 9.5 increased methanol production.« less

Modeling SOA formation from the oxidation of intermediate volatility n-alkanes

NASA Astrophysics Data System (ADS)

Aumont, B.; Valorso, R.; Mouchel-Vallon, C.; Camredon, M.; Lee-Taylor, J.; Madronich, S.

2012-08-01

The chemical mechanism leading to SOA formation and ageing is expected to be a multigenerational process, i.e. a successive formation of organic compounds with higher oxidation degree and lower vapor pressure. This process is here investigated with the explicit oxidation model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere). Gas phase oxidation schemes are generated for the C8-C24 series of n-alkanes. Simulations are conducted to explore the time evolution of organic compounds and the behavior of secondary organic aerosol (SOA) formation for various preexisting organic aerosol concentration (COA). As expected, simulation results show that (i) SOA yield increases with the carbon chain length of the parent hydrocarbon, (ii) SOA yield decreases with decreasing COA, (iii) SOA production rates increase with increasing COA and (iv) the number of oxidation steps (i.e. generations) needed to describe SOA formation and evolution grows when COA decreases. The simulated oxidative trajectories are examined in a two dimensional space defined by the mean carbon oxidation state and the volatility. Most SOA contributors are not oxidized enough to be categorized as highly oxygenated organic aerosols (OOA) but reduced enough to be categorized as hydrocarbon like organic aerosols (HOA), suggesting that OOA may underestimate SOA. Results show that the model is unable to produce highly oxygenated aerosols (OOA) with large yields. The limitations of the model are discussed.

Modeling SOA formation from the oxidation of intermediate volatility n-alkanes

NASA Astrophysics Data System (ADS)

Aumont, B.; Valorso, R.; Mouchel-Vallon, C.; Camredon, M.; Lee-Taylor, J.; Madronich, S.

2012-06-01

The chemical mechanism leading to SOA formation and ageing is expected to be a multigenerational process, i.e. a successive formation of organic compounds with higher oxidation degree and lower vapor pressure. This process is here investigated with the explicit oxidation model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere). Gas phase oxidation schemes are generated for the C8-C24 series of n-alkanes. Simulations are conducted to explore the time evolution of organic compounds and the behavior of secondary organic aerosol (SOA) formation for various preexisting organic aerosol concentration (COA). As expected, simulation results show that (i) SOA yield increases with the carbon chain length of the parent hydrocarbon, (ii) SOA yield decreases with decreasing COA, (iii) SOA production rates increase with increasing COA and (iv) the number of oxidation steps (i.e. generations) needed to describe SOA formation and evolution grows when COA decreases. The simulated oxidative trajectories are examined in a two dimensional space defined by the mean carbon oxidation state and the volatility. Most SOA contributors are not oxidized enough to be categorized as highly oxygenated organic aerosols (OOA) but reduced enough to be categorized as hydrocarbon like organic aerosols (HOA), suggesting that OOA may underestimate SOA. Results show that the model is unable to produce highly oxygenated aerosols (OOA) with large yields. The limitations of the model are discussed.

A single-blind controlled study of electrocautery and ultrasonic scalpel smoke plumes in laparoscopic surgery.

PubMed

Fitzgerald, J Edward F; Malik, Momin; Ahmed, Irfan

2012-02-01

Surgical smoke containing potentially carcinogenic and irritant chemicals is an inevitable consequence of intraoperative energized dissection. Different energized dissection methods have not been compared directly in human laparoscopic surgery or against commonly encountered pollutants. This study undertook an analysis of carcinogenic and irritant volatile hydrocarbon concentrations in electrocautery and ultrasonic scalpel plumes compared with cigarette smoke and urban city air control samples. Once ethical approval was obtained, gas samples were aspirated from the peritoneal cavity after human laparoscopic intraabdominal surgery solely using either electrocautery or ultrasonic scalpels. All were adsorbed in Tenax tubes and concentrations of carcinogenic or irritant volatile hydrocarbons measured by gas chromatography. The results were compared with cigarette smoke and urban city air control samples. The analyzing laboratory was blinded to sample origin. A total of 10 patients consented to intraoperative gas sampling in which only one method of energized dissection was used. Six carcinogenic or irritant hydrocarbons (benzene, ethylbenzene, styrene, toluene, heptene, and methylpropene) were identified in one or more samples. With the exception of styrene (P = 0.016), a nonsignificant trend toward lower hydrocarbon concentrations was observed with ultrasonic scalpel use. Ultrasonic scalpel plumes had significantly lower hydrocarbon concentrations than cigarette smoke, with the exception of methylpropene (P = 0.332). No significant difference was observed with city air. Electrocautery samples contained significantly lower hydrocarbon concentrations than cigarette smoke, with the exception of toluene (P = 0.117) and methyl propene (P = 0.914). Except for toluene (P = 0.028), city air showed no significant difference. Both electrocautery and ultrasonic dissection are associated with significantly lower concentrations of the most commonly detected carcinogenic and irritant hydrocarbons than cigarette smoke. A nonsignificant trend toward lower hydrocarbon concentrations was seen with ultrasonic scalpel dissection compared with diathermy. The contamination levels in city air were largely comparable with those seen after ultrasonic scalpel use. Although hydrocarbon concentrations are low, cumulative exposures may increase health risks. Where concerns arise, ultrasonic scalpel dissection may be preferable.

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

PubMed

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

2007-12-01

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

Volatile organic components migrating from plastic pipes (HDPE, PEX and PVC) into drinking water.

PubMed

Skjevrak, Ingun; Due, Anne; Gjerstad, Karl Olav; Herikstad, Hallgeir

2003-04-01

High-density polyethylene pipes (HDPE), crossbonded polyethylene pipes (PEX) and polyvinyl chloride (PVC) pipes for drinking water were tested with respect to migration of volatile organic components (VOC) to water. The odour of water in contact with plastic pipes was assessed according to the quantitative threshold odour number (TON) concept. A major migrating component from HDPE pipes was 2,4-di-tert-butyl-phenol (2,4-DTBP) which is a known degradation product from antioxidants such as Irgafos 168(R). In addition, a range of esters, aldehydes, ketones, aromatic hydrocarbons and terpenoids were identified as migration products from HDPE pipes. Water in contact with HDPE pipes was assessed with respect to TON, and values > or =4 were determined for five out of seven brands of HDPE pipes. The total amount of VOC released to water during three successive test periods were fairly constant for the HDPE pipes. Corresponding migration tests carried out for PEX pipes showed that VOC migrated in significant amounts into the test water, and TON >/=5 of the test water were observed in all tests. Several of the migrated VOC were not identified. Oxygenates predominated the identified VOC in the test water from PEX pipes. Migration tests of PVC pipes revealed few volatile migrants in the test samples and no significant odour of the test water.

Volatile Compounds Produced by Lactobacillus paracasei During Oat Fermentation.

PubMed

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

2016-12-01

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

Isotopic analyses of nitrogenous compounds from the Murchison meteorite: ammonia, amines, amino acids, and polar hydrocarbons

NASA Technical Reports Server (NTRS)

Pizzarello, S.; Feng, X.; Epstein, S.; Cronin, J. R.

1994-01-01

The combined volatile bases (ammonia, aliphatic amines, and possibly other bases), ammonia, amino acids, and polar hydrocarbons were prepared from the Murchison meteorite for isotopic analyses. The volatile bases were obtained by cryogenic transfer after acid-hydrolysis of a hot-water extract and analyzed by combined gas chromatography-mass spectrometry of pentafluoropropionyl derivatives. The aliphatic amines present in this preparation comprise a mixture that includes both primary and secondary isomers through C5 at a total concentration of > or = 100 nmoles g-1. As commonly observed for meteoritic organic compounds, almost all isomers through C5 are present, and the concentrations within homologous series decrease with increasing chain length. Ammonia was chromatographically separated from the other volatile bases and found at a concentration of 1.1-1.3 micromoles g-1 meteorite. The ammonia analyzed includes contributions from ammonium salts and the hydrolysis of extractable organic compounds, e.g., carboxamides. Stable isotope analyses showed the volatile bases to be substantially enriched in the heavier isotopes, relative to comparable terrestrial compounds delta D < or = +1221%; delta 13C = +22%; delta 15N = +93%). Ammonia, per se, was found to have a somewhat lower delta 15N value (+69%) than the total volatile bases; consequently, a higher delta 15N (>93%) can be inferred for the other bases, which include the amines. Solvent-extractable polar hydrocarbons obtained separately were found to be enriched in 15N (delta 15N = +104%). Total amino acids, prepared from a hydrolyzed hot-water extract by cation exchange chromatography, gave a delta 15N of +94%, a value in good agreement with that obtained previously. Nitrogen isotopic data are also given for amino acid fractions separated chromatographically. The delta 15N values of the Murchison soluble organic compounds analyzed to date fall within a rather narrow range (delta 15N = +94 +/- 8%), an observation consistent with their formation, or formation of their precursors, by interstellar chemistry.

Profiles of Volatile Compounds in Black Currant (Ribes nigrum) Cultivars with Special Focus on Influence of Growth Latitude and Weather Conditions.

PubMed

Marsol-Vall, Alexis; Kortesniemi, Maaria Katariina; Karhu, Saila; Kallio, Heikki; Yang, Baoru

2018-06-25

The volatile profile of three blackcurrant (Ribes nigrum L.) cultivars grown in Finland and their response to growth latitude and weather conditions were studied over an eight-year period by headspace solid-phase microextraction (HS-SPME) followed by gas chromatographic-mass spectrometric (GC-MS) analysis. Monoterpene hydrocarbons and oxygenated monoterpenes were the major classes of volatiles. The cultivar 'Melalahti' presented lower content of volatiles compared with 'Ola' and 'Mortti', the two latter showing a very similar composition. Higher contents of volatiles were found in berries cultivated at higher latitude (66° 34' N) than in those from the southern location (60° 23' N). Among the meteorological variables, radiation and temperature during the last month before harvest were negatively linked with the volatile content. Storage time had a negative impact on the amount of blackcurrant volatiles.

Volatile compounds of Celta dry-cured 'lacón' as affected by cross-breeding with Duroc and Landrace genotypes.

PubMed

Lorenzo, José M; Fonseca, Sonia

2014-11-01

Dry-cured 'lacón' is a traditional cured meat product made in the north-west of Spain from the pigs' foreleg, with similar manufacturing process to that used in dry-cured ham. The aim of this study was to assess the influence of cross-breeding of Celta pig with Landrace or Duroc breeds on the formation of volatile compounds through the manufacture of 'lacón'. 'Lacón' from the crosses with Duroc presented lower final moisture (534 g kg(-1) ) and higher intra-muscular fat content [144 g kg(-1) dry matter (DM)] than 'lacón' from Celta pure breed (587 g kg(-1) and 36 g kg(-1) DM, respectively). Volatile compounds were extracted by solid-phase microextraction and analysed by gas chromatography-mass spectrometry. Volatile compounds from 'lacón' were affected by cross-breeding. The total amount of volatile compounds significantly (P < 0.001) increased during the manufacturing process, this increase being more marked in samples from the Landrace cross-breed. The most abundant group of flavour compounds at the end of the manufacturing process was esters in the three batches, followed by aldehydes, hydrocarbons and alcohols. The most abundant ester at the end of the process was hexanoic acid methyl ester, while the aldehyde found in a higher amount was hexanal. The profile of volatile compounds was affected by cross-breed, especially at the end of the 'lacón' dry-curing process. © 2014 Society of Chemical Industry.

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

NASA Astrophysics Data System (ADS)

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

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

Determination of volatile organic hydrocarbons in water samples by solid-phase dynamic extraction.

PubMed

Jochmann, Maik A; Yuan, Xue; Schmidt, Torsten C

2007-03-01

In the present study a headspace solid-phase dynamic extraction method coupled to gas chromatography-mass spectrometry (HS-SPDE-GC/MS) for the trace determination of volatile halogenated hydrocarbons and benzene from groundwater samples was developed and evaluated. As target compounds, benzene as well as 11 chlorinated and brominated hydrocarbons (vinyl chloride, dichloromethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, bromoform) of environmental and toxicological concern were included in this study. The analytes were extracted using a SPDE needle device, coated with a poly(dimethylsiloxane) with 10% embedded activated carbon phase (50-microm film thickness and 56-mm film length) and were analyzed by GC/MS in full-scan mode. Parameters that affect the extraction yield such as extraction and desorption temperature, salting-out, extraction and desorption flow rate, extraction volume and desorption volume, the number of extraction cycles, and the pre-desorption time have been evaluated and optimized. The linearity of the HS-SPDE-GC/MS method was established over several orders of magnitude. Method detection limits (MDLs) for the compounds investigated ranged between 12 ng/L for cis-dichloroethylene and trans-dichloroethylene and 870 ng/L for vinyl chloride. The method was thoroughly validated, and the precision at two concentration levels (0.1 mg/L and a concentration 5 times above the MDL) was between 3.1 and 16% for the analytes investigated. SPDE provides high sensitivity, short sample preparation and extraction times and a high sample throughput because of full automation. Finally, the applicability to real environmental samples is shown exemplarily for various groundwater samples from a former waste-oil recycling facility. Groundwater from the site showed a complex contamination with chlorinated volatile organic compounds and aromatic hydrocarbons.

Discriminative stimulus effects of inhaled1,1,1-trichloroethane in mice: comparison to other hydrocarbon vapors and volatile anesthetics

PubMed Central

Shelton, Keith L.

2009-01-01

Rationale Because the toxicity of many inhalants precludes evaluation in humans, drug discrimination, an animal model of subjective effects, can be used to gain insights on their poorly understood abuse-related effects. Objectives The purpose of the present study was to train a prototypic inhalant that has known abuse liability, 1,1,1-trichloroethane (TCE), as a discriminative stimulus in mice and compare it to other classes of inhalants. Methods Eight B6SJLF1/J mice were trained to discriminate 10 min of exposure to 12000 ppm inhaled TCE vapor from air and seven mice were trained to discriminate 4000 ppm TCE from air. Tests were then conducted to characterize the discriminative stimulus of TCE and to compare it to representative aromatic and chlorinated hydrocarbon vapors, volatile halogenated anesthetics as well as an odorant compound. Results Only the 12000 ppm TCE versus air discrimination group exhibited sufficient discrimination accuracy for substitution testing. TCE vapor concentration- and exposure time-dependently substituted for the 12000 ppm TCE vapor training stimulus. Full substitution was produced by trichloroethylene, toluene, enflurane and sevoflurane. Varying degrees of partial substitution were produced by the other volatile test compounds. The odorant, 2-butanol, did not produce any substitution for TCE. Conclusions The discriminative stimulus effects of TCE are shared fully or partially by chlorinated and aromatic hydrocarbons as well as by halogenated volatile anesthetics. However, these compounds can be differentiated from TCE both quantitatively and qualitatively. It appears that the degree of similarity is not solely a function of chemical classification but may also be dependent upon the neurochemical effects of the individual compounds. PMID:18972104

Severe acute respiratory distress syndrome caused by unintentional sewing machine lubricant ingestion: A case report.

PubMed

Kishore, Sunil; Chandelia, Sudha; Patharia, Neha; Swarnim

2016-11-01

Sewing machine oil ingestion is rare but is possible due to its availability at home. Chemically, it belongs to hydrocarbon family which is toxic if aspirated, owing to their physical properties such as high volatility and low viscosity. On the contrary, sewing machine lubricant has high viscosity and low volatility which makes it aspiration less likely. The main danger of hydrocarbon ingestion is chemical pneumonitis which may be as severe as acute respiratory distress syndrome (ARDS). We report a case of a 5-year-old girl with accidental ingestion of sewing machine lubricant oil, who subsequently developed ARDS refractory to mechanical ventilation. There was much improvement with airway pressure release ventilation mode of ventilation, but the child succumbed to death due to pulmonary hemorrhage.

Severe acute respiratory distress syndrome caused by unintentional sewing machine lubricant ingestion: A case report

PubMed Central

Kishore, Sunil; Chandelia, Sudha; Patharia, Neha; Swarnim

2016-01-01

Sewing machine oil ingestion is rare but is possible due to its availability at home. Chemically, it belongs to hydrocarbon family which is toxic if aspirated, owing to their physical properties such as high volatility and low viscosity. On the contrary, sewing machine lubricant has high viscosity and low volatility which makes it aspiration less likely. The main danger of hydrocarbon ingestion is chemical pneumonitis which may be as severe as acute respiratory distress syndrome (ARDS). We report a case of a 5-year-old girl with accidental ingestion of sewing machine lubricant oil, who subsequently developed ARDS refractory to mechanical ventilation. There was much improvement with airway pressure release ventilation mode of ventilation, but the child succumbed to death due to pulmonary hemorrhage. PMID:27994384

Marine and terrestrial sources of reactive volatile organic compounds and their impact on the tropospheric ozone chemistry of the earth

NASA Astrophysics Data System (ADS)

Riemer, Daniel David

Two areas integral to the global cycle of tropospheric ozone were studied. The first segment of this investigation involved the study of marine ecosystems to define the sources of nonmethane hydrocarbons (NMHCs) in the surface ocean. This included laboratory and field investigations conducted to determine the function and importance of dissolved organic matter (DOM) in the abiotic photochemical production of nonmethane hydrocarbons (NMHCs) in surface seawater. Concurrently, phytoplankton were investigated as a biogenic source of NMHCs in the surface ocean. Low molecular weight alkenes, compounds observed in the greatest quantities in the surface ocean, are formed almost exclusively as a result of DOM-mediated photochemistry. Isoprene was found to be produced by all phytoplankton species investigated. The primary sink for NMHCs found in surface seawater was gas exchange. The second segment of this study focused on the prevalence of NMHCs and oxygenated volatile organic compounds (OVOCs) in the rural southeastern United States. To characterize the importance of NMHCs and OVOCs to the process of atmospheric reactivity and tropospheric ozone chemistry, mixing ratios for a number of NMHCs and OVOCs were determined. Isoprene and its primary oxidation products, methacrolein and methyl vinyl ketone, were observed to be the dominant hydroxyl radical (OH) sink in the rural atmosphere. Certain OVOCs, namely methanol, acetone and acetaldehyde-although not as important on a reactivity basis-were the most prevalent in terms of mass. Methanol was the dominant OVOC measured in the rural atmosphere and serves as an important source of formaldehyde in the rural atmosphere. On the basis of the mixing ratio patterns exhibited by many of the OVOCs present in the rural atmosphere, considerable biogenic sources are likely.

The Metabolism of Tetralin in Fischer 344 Rats

DTIC Science & Technology

1986-04-01

evaluated petroleum and shale-derived JP-5, a jet fuel composed of aliphatic and aromatic hydrocarbons with the majority of the straight-chain...much like gasoline. JP-8 is a mixture of hydrocarbons of intermediate boiling point and volatility and is similar to the civilian jet fuel , A-1. DFM...toxicity of conventional versus shale-derived JP-5 jet fuel : Light microscopy, hematologic, and serum chemistry studies. Toxicol Appl Pharmacol, 57

An Air-Stripping Packed Bed Combined with a Biofilm-Type Biological Process for Treating BTEX and Total Petroleum Hydrocarbon Contaminated Groudwater

NASA Astrophysics Data System (ADS)

Hong, U.; Park, S.; Lim, J.; Lee, W.; Kwon, S.; Kim, Y.

2009-12-01

In this study, we examined the removal efficiency of a volatile compound (e.g. toluene) and a less volatile compound [e.g. total petroleum hydrocarbon (TPH)] using an air stripping packed bed combined with a biofilm-type biological process. We hypothesized that this system might be effective and economical to simultaneously remove both volatile and less volatile compounds. The gas-tight reactor has 5.9-inch-diameter and 48.8-inch-height. A spray nozzle was installed at the top cover to distribute the liquid evenly through reactor. The reactor was filled with polypropylene packing media for the increase of volatilization surface area and the growth of TPH degrading facultative aerobic bacteria on the surface of the packing media. In air stripping experiments, 45.6%, 71.7%, 72.0%, and 75.4% of toluene was removed at air injection rates of 0 L/min, 2.5 L/min, 4 L/min, and 6 L/min, respectively. Through the result, we confirmed that toluene removal efficiency increased by injecting higher amounts of air. TPH removal by stripping was minimal. To remove a less volatile TPH by commercial TPH degrading culture (BIO-ZYME B-52), 15-times diluted culture was circulated through the reactor for 2-3 days to build up a biofilm on the surface of packing media with 1 mg-soluble nitrogen source /L-water per 1 ppm of TPH. Experiments evaluating the degree of TPH biodegradation in this system are carrying out.

Power-dependent speciation of volatile organic compounds in aircraft exhaust

NASA Astrophysics Data System (ADS)

Beyersdorf, Andreas J.; Thornhill, K. Lee; Winstead, Edward L.; Ziemba, Luke D.; Blake, Donald R.; Timko, Michael T.; Anderson, Bruce E.

2012-12-01

As part of the third NASA Aircraft Particle Emissions Experiment (APEX-3, November 2005), whole air samples were collected to determine the emission rates of volatile organic compounds (VOCs) from aircraft equipped with three different gas-turbine engines (an Allison Engine 3007-A1E, a Pratt-Whitney 4158, and a Rolls-Royce RB211-535E4B). Samples were collected 1 m behind the engine exhaust plane of the engines while they were operated at powers ranging from idle up to 30% of maximum rated thrust. Exhaust emission indices (mass emitted per kilogram of fuel used) for CO and non-methane hydrocarbons (NMHCs) were calculated based on enhancements over background relative to CO2. Emissions of all NMHCs were greatest at low power with values decreasing by an order of magnitude with increasing power. Previous studies have shown that scaling idle hydrocarbon emissions to formaldehyde or ethene (which are typically emitted at a ratio of 1-to-1 at idle) reduces variability amongst engine types. NMHC emissions were found to scale at low power, with alkenes contributing over 50% of measured NMHCs. However, as the power increases hydrocarbon emissions no longer scale to ethene, as the aromatics become the dominant species emitted. This may be due in part to a shift in combustion processes from thermal cracking (producing predominantly alkenes) to production of new molecules (producing proportionally more aromatics) as power increases. The formation of these aromatics is an intermediate step in the production of soot, which also increases with increasing power. The increase in aromatics relative to alkenes additionally results in a decrease in the hydroxyl radical reactivity and ozone formation potential of aircraft exhaust. Samples collected 30 m downwind of the engine were also analyzed for NMHCs and carbonyl compounds (acetone, 2-butanone and C1-C9 aldehydes). Formaldehyde was the predominant carbonyl emitted; however, the ratio of ethene-to-formaldehyde varied between the aircraft, possibly due to the sampling of transient emissions such as engine start-up and power changes. A large portion of the measured emissions (27-42% by mass) in the plume samples was made up of hazardous air pollutants (HAPs) with oxygenated compounds being most significant.

Improved Satellite-based Photosysnthetically Active Radiation (PAR) for Air Quality Studies

NASA Astrophysics Data System (ADS)

Pour Biazar, A.; McNider, R. T.; Cohan, D. S.; White, A.; Zhang, R.; Dornblaser, B.; Doty, K.; Wu, Y.; Estes, M. J.

2015-12-01

One of the challenges in understanding the air quality over forested regions has been the uncertainties in estimating the biogenic hydrocarbon emissions. Biogenic volatile organic compounds, BVOCs, play a critical role in atmospheric chemistry, particularly in ozone and particulate matter (PM) formation. In southeastern United States, BVOCs (mostly as isoprene) are the dominant summertime source of reactive hydrocarbon. Despite significant efforts in improving BVOC estimates, the errors in emission inventories remain a concern. Since BVOC emissions are particularly sensitive to the available photosynthetically active radiation (PAR), model errors in PAR result in large errors in emission estimates. Thus, utilization of satellite observations to estimate PAR can help in reducing emission uncertainties. Satellite-based PAR estimates rely on the technique used to derive insolation from satellite visible brightness measurements. In this study we evaluate several insolation products against surface pyranometer observations and offer a bias correction to generate a more accurate PAR product. The improved PAR product is then used in biogenic emission estimates. The improved biogenic emission estimates are compared to the emission inventories over Texas and used in air quality simulation over the period of August-September 2013 (NASA's Discover-AQ field campaign). A series of sensitivity simulations will be performed and evaluated against Discover-AQ observations to test the impact of satellite-derived PAR on air quality simulations.

Modeling SOA production from the oxidation of intermediate volatility alkanes

NASA Astrophysics Data System (ADS)

Aumont, B.; Mouchel-Vallon, C.; Camredon, M.; Lee-Taylor, J.; Madronich, S.

2012-12-01

Secondary Organic Aerosols (SOA) production and ageing is a multigenerational oxidation process involving the formation of successive organic compounds with higher oxidation degree and lower vapour pressure. This process was investigated using the explicit oxidation model GECKO-A (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere). Results for the C8-C24 n-alkane series show the expected trends, i.e. (i) SOA yield grows with the carbon backbone of the parent hydrocarbon, (ii) SOA yields decreases with the decreasing pre-existing organic aerosol concentration, (iii) the number of generations required to describe SOA production increases when the pre-existing organic aerosol concentration decreases. Most SOA contributors were found to be not oxidized enough to be categorized as highly oxygenated organic aerosols (OOA) but reduced enough to be categorized as hydrocarbon like organic aerosols (HOA). Branched alkanes are more prone to fragment in the early stage of the oxidation than their corresponding linear analogues. Fragmentation is expected to alter both the yield and the mean oxidation state of the SOA. Here, GECKO-A is applied to generate highly detailed oxidation schemes for various series of branched and cyclised alkanes. Branching and cyclisation effects on SOA yields and oxidation states will be examined.

Enhanced Characterization of the Smell of Death by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GCxGC-TOFMS)

PubMed Central

Dekeirsschieter, Jessica; Stefanuto, Pierre-Hugues; Brasseur, Catherine; Haubruge, Eric; Focant, Jean-François

2012-01-01

Soon after death, the decay process of mammalian soft tissues begins and leads to the release of cadaveric volatile compounds in the surrounding environment. The study of postmortem decomposition products is an emerging field of study in forensic science. However, a better knowledge of the smell of death and its volatile constituents may have many applications in forensic sciences. Domestic pigs are the most widely used human body analogues in forensic experiments, mainly due to ethical restrictions. Indeed, decomposition trials on human corpses are restricted in many countries worldwide. This article reports on the use of comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) for thanatochemistry applications. A total of 832 VOCs released by a decaying pig carcass in terrestrial ecosystem, i.e. a forest biotope, were identified by GCxGC-TOFMS. These postmortem compounds belong to many kinds of chemical class, mainly oxygen compounds (alcohols, acids, ketones, aldehydes, esters), sulfur and nitrogen compounds, aromatic compounds such as phenolic molecules and hydrocarbons. The use of GCxGC-TOFMS in study of postmortem volatile compounds instead of conventional GC-MS was successful. PMID:22723918

Collaborative Research: Nanopore Confinement of C-H-O Mixed Volatile Fluids Relevant to Subsurface Energy Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grady, Brian P.

2015-03-11

The scientific objective of this proposal was to obtain a fundamental atomic- to macro-scale understanding of the sorptivity, structure and dynamics of simple and complex hydrocarbon (HC) fluids at mineral surfaces or within nanoporous matrices over temperatures, pressures and compositions encountered in near-surface and shallow crustal environments. The research supported by this award was complementary to that conducted by the group of Prof. David cole at Ohio State University. The scope of the present award was to utilize molecular-level modeling to provide critically important insights into the interfacial properties of mineral-volatile systems, assist in the interpretation of experimental data andmore » predict fluid behavior beyond the limits of current experimental capability. During the past three years the effort has focused primarily on the behavior of C-H volatiles including methane (CH 4) and propane (C 3H 8), mixed-volatile systems including hydrocarbon - CO 2 with and without H 2O present. The long-range goal is to quantitatively link structure, dynamics and reactivity in complex mineral-/C-H-O systems from the atomic to the molecular to the macroscopic levels. The results are relevant to areas of growing importance such as gas shale, HC-bearing hydrothermal systems, and CO 2 storage.« less

Method for recovering light hydrocarbons from coal agglomerates

DOEpatents

Huettenhain, Horst; Benz, August D.; Getsoian, John

1991-01-01

A method and apparatus for removing light hydrocarbons, such as heptane, from coal agglomerates includes an enclosed chamber having a substantially horizontal perforate surface therein. The coal agglomerates are introduced into a water bath within the chamber. The agglomerates are advanced over the surface while steam is substantially continuously introduced through the surface into the water bath. Steam heats the water and causes volatilization of the light hydrocarbons, which may be collected from the overhead of the chamber. The resulting agglomerates may be collected at the opposite end from the surface and subjected to final draining processes prior to transportation or use.

Effect of persistent trace compounds in landfill gas on engine performance during energy recovery: a case study.

PubMed

Sevimoğlu, Orhan; Tansel, Berrin

2013-01-01

Performances of gas engines operated with landfill gas (LFG) are affected by the impurities in the LFG, reducing the economic viability of energy recovery. The purpose of this study was to characterize the trace compounds in the LFG at the Odayeri Landfill, Istanbul, Turkey which is used for energy recovery. Composite gas samples were collected and analyzed for trace compounds (hydrocarbons, siloxanes, and volatile halogenated hydrocarbons) over a 3-year period. Trace compounds entering the gas engines, their impact on the engine performance were evaluated. The operational problems included deposit formation in the combustion chamber, turbocharger, and intercooler of engine before the scheduled maintenance times. High levels of hydrogen sulfide, as well as chlorinated and fluorinated compounds cause corrosion of the engine parts and decrease life of the engine oils. Persistence of siloxanes results in deposit formation, increasing engine maintenance costs. Pretreatment of LFG is necessary to protect the engines at the waste-to-energy facilities with persistence levels of siloxanes and volatile halogenated hydrocarbons. Copyright © 2012 Elsevier Ltd. All rights reserved.

Combustor exhaust-emissions and blowout-limits with diesel number 2 and Jet A fuels utilizing air-atomizing and pressure-atomizing nozzles

NASA Technical Reports Server (NTRS)

Ingebo, R. D.; Norgren, C. T.

1975-01-01

The effect of fuel properties on exhaust emissions and blowout limits of a high-pressure combustor segment is evaluated using a splash-groove air-atomizing fuel injector and a pressure-atomizing simplex fuel nozzle to burn both diesel number 2 and Jet A fuels. Exhaust emissions and blowout data are obtained and compared on the basis of the aromatic content and volatility of the two fuels. Exhaust smoke number and emission indices for oxides of nitrogen, carbon monoxide, and unburned hydrocarbons are determined for comparison. As compared to the pressure-atomizing nozzle, the air-atomizing nozzle is found to reduce nitrogen oxides by 20%, smoke number by 30%, carbon monoxide by 70%, and unburned hydrocarbons by 50% when used with diesel number 2 fuel. The higher concentration of aromatics and lower volatility of diesel number 2 fuel as compared to Jet A fuel appears to have the most detrimental effect on exhaust emissions. Smoke number and unburned hydrocarbons are twice as high with diesel number 2 as with Jet A fuel.

Effect of cooking on radiation-induced chemical markers in beef and pork during storage.

PubMed

Kwon, Joong-Ho; Kwon, Youngju; Kausar, Tusneem; Nam, Ki-Chang; Rok Min, Byong; Joo Lee, Eun; Ahn, Dong U

2012-02-01

Raw and cooked beef and pork loins were irradiated at 0 or 5 kGy. The radiation-induced marker compounds, such as hydrocarbons, 2-alkylcyclobutanones (2-ACBs), and sulfur volatiles, were determined after 0 and 6 mo of frozen storage. Two hydrocarbons (8-heptadecene [C(17:1)] and 6,9-heptadecadiene [C(17:2)]) and two 2-ACBs (2-dodecylcyclobutanone [2-DCB] and 2-tetradecylcyclobutanone [2-TCB]) were detected only in irradiated raw and cooked meats. Although precooked irradiated meats produced more hydrocarbons and 2-ACBs than the irradiated cooked ones, the amounts of individual hydrocarbons and 2-ACBs, such as 8-heptadecene, 6,9-heptadecadiene, 2-DCB, and 2-TCB, were sufficient enough to detect whether the meat was irradiated or not. Dimethyl disulfide and dimethyl trisulfide were also determined only in irradiated meats but dimethyl trisulfide disappeared after 6 mo of frozen storage under oxygen-permeable packaging conditions. The results indicated that 8-heptadecene, 6,9-heptadecadiene, 2-DCB, 2-TCB, and dimethyl disulfide, even though they were decreased with storage, could be used as marker compounds for the detection of irradiated beef and pork regardless of cooking under the frozen conditions for 6 mo. Radiation-induced chemical changes such as specific hydrocarbons, 2-ACBs, and sulfur volatiles may be used as potential identification markers by regulatory authorities to confirm irradiation history of frozen stored raw or cooked beef and pork. © 2012 Institute of Food Technologists®

Primary emissions and secondary formation of volatile organic compounds from natural gas production in five major U.S. shale plays

NASA Astrophysics Data System (ADS)

Gilman, J.; Lerner, B. M.; Warneke, C.; Graus, M.; Lui, R.; Koss, A.; Yuan, B.; Murphy, S. M.; Alvarez, S. L.; Lefer, B. L.; Min, K. E.; Brown, S. S.; Roberts, J. M.; Osthoff, H. D.; Hatch, C. D.; Peischl, J.; Ryerson, T. B.; De Gouw, J. A.

2014-12-01

According to the U.S. Energy and Information Administration (EIA), domestic production of natural gas from shale formations is currently at the highest levels in U.S. history. Shale gas production may also result in the production of natural gas plant liquids (NGPLs) such as ethane and propane as well as natural gas condensate composed of a complex mixture of non-methane hydrocarbons containing more than ~5 carbon atoms (e.g., hexane, cyclohexane, and benzene). The amounts of natural gas liquids and condensate produced depends on the particular reservoir. The source signature of primary emissions of hydrocarbons to the atmosphere within each shale play will therefore depend on the composition of the raw natural gas as well as the industrial processes and equipment used to extract, separate, store, and transport the raw materials. Characterizing the primary emissions of VOCs from natural gas production is critical to assessing the local and regional atmospheric impacts such as the photochemical formation of ozone and secondary formation of organic aerosol. This study utilizes ground-based measurements of a full suite of volatile organic compounds (VOCs) in two western U.S. basins, the Uintah (2012-2014 winter measurements only) and Denver-Julesburg (winter 2011 and summer 2012), and airborne measurements over the Haynesville, Fayetteville, and Marcellus shale basins (summer 2013). By comparing the observed VOC to propane enhancement ratios, we show that each basin has a unique VOC source signature associated with oil and natural gas operations. Of the shale basins studied, the Uintah basin had the largest overall VOC to propane enhancement ratios while the Marcellus had the lowest. For the western basins, we will compare the composition of oxygenated VOCs produced from photochemical oxidation of VOC precursors and contrast the oxygenated VOC mixture to a "typical" summertime urban VOC mixture. The relative roles of alkanes, alkenes, aromatics, and cycloalkanes as precursors for C2-C6 aldehydes and ketones, and C3-C4 alkyl nitrates will be investigated.

Polycyclic aromatic hydrocarbons - fate and long-range atmospheric transport studied using a global model, EMAC-SVOC

NASA Astrophysics Data System (ADS)

Octaviani, Mega; Tost, Holger; Lammel, Gerhard

2017-04-01

Polycyclic aromatic hydrocarbons (PAHs) are emitted by incomplete combustion from fossil fuel, vehicles, and biomass burning. They may persist in environmental compartments, pose a health hazard and may bio accumulate along food chains. The ECHAM/MESSy Atmospheric Chemistry (EMAC) model had been used to simulate global tropospheric, stratospheric chemistry and climate. In this study, we improve the model to include simulations of the transport and fate of semi-volatile organic compounds (SVOC). The EMAC-SVOC model takes into account essential environmental processes including gas-particle partitioning, dry and wet deposition, chemical and bio-degradation, and volatilization from sea surface, soils, vegetation, and snow. The model was evaluated against observational data in the Arctic, mid-latitudes, and tropics, and further applied to study total environmental lifetime and long-range transport potential (LRTP) of PAHs. We selected four compounds for study, spanning a wide range of volatility, i.e., phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene. Several LRTP indicators were investigated, including the Arctic contamination potential, meridional spreading, and zonal and meridional fluxes to remote regions.

Paleogene stratigraphy of the Solomons Island, Maryland corehole

USGS Publications Warehouse

Gibson, Thomas G.; Bybell, Laurel M.

1994-01-01

Purge and trap capillary gas chromatography/mass spectrometry is a rapid, precise, accurate method for determining volatile organic compounds in samples of surface water and ground water. The method can be used to determine 59 selected compounds, including chlorofluorohydrocarbons, aromatic hydrocarbons, and halogenated hydrocarbons. The volatile organic compounds are removed from the sample matrix by actively purging the sample with helium. The volatile organic compounds are collected onto a sorbant trap, thermally desorbed, separated by a Megabore gas chromatographic capillary column, ionized by electron impact, and determined by a full-scan quadrupole mass spectrometer. Compound identification is confirmed by the gas chromatographic retention time and by the resultant mass spectrum. Unknown compounds detected in a sample can be tentatively identified by comparing the unknown mass spectrum to reference spectra in the mass-spectra computer-data system library compiled by the National Institute of Standards and Technology. Method detection limits for the selected compounds range from 0.05 to 0.2 microgram per liter. Recoveries for the majority of the selected compounds ranged from 80 to 120 percent, with relative standard deviations of less than 10 percent.

Evolution of Volatile Emission in Rhus coriaria Organs During Different Stages of Growth and Evaluation of the Essential Oil Composition.

PubMed

Reidel, Rose Vanessa Bandeira; Cioni, Pier Luigi; Majo, Luigi; Pistelli, Luisa

2017-11-01

Rhus coriaria, also known as Sumac, has been traditionally used in many countries as spice, condiment, dying agent, and medicinal herb. The chemical composition of essential oils (EOs) and the volatile emissions from different organs of this species collected in Sicily (Italy) were analyzed by gas chromatography-flame ionization detection and gas chromatography/mass spectrometry. Monoterpene and sesquiterpene hydrocarbons were the most abundant class in the volatile emissions with β-caryophyllene and α-pinene were the main constituents in the majority of the examined samples. The EO composition was characterized by high amount of monoterpene and sesquiterpene hydrocarbons together with diterpenes. The main compounds in the EO obtained from the leaves and both stages of fruit maturation were cembrene and β-caryophyllene, while α-pinene and tridecanoic acid were the key compounds in the flower EO. All the data were submitted to multivariate statistical analysis showing many differences among the different plant parts and their ontogenetic stages. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Emissions of volatile organic compounds (VOCs) from oil and natural gas activities: compositional comparison of 13 major shale basins via NOAA airborne measurements

NASA Astrophysics Data System (ADS)

Gilman, J.; Lerner, B. M.; Aikin, K. C.; De Gouw, J. A.; Koss, A.; Yuan, B.; Warneke, C.; Peischl, J.; Ryerson, T. B.; Holloway, J. S.; Graus, M.; Tokarek, T. W.; Isaacman-VanWertz, G. A.; Sueper, D.; Worsnop, D. R.

2015-12-01

The recent and unprecedented increase in natural gas production from shale formations is associated with a rise in the production of non-methane volatile organic compounds (VOCs) including natural gas plant liquids (e.g., ethane, propane, and butanes) and liquid lease condensate (e.g., pentanes, hexanes, aromatics and cycloalkanes). Since 2010, the production of natural gas liquids and the amount of natural gas vented/flared has increased by factors of ~1.28 and 1.57, respectively (U.S. Energy and Information Administration), indicating an increasingly large potential source of hydrocarbons to the atmosphere. Emission of VOCs may affect local and regional air quality due to the potential to form tropospheric ozone and organic particles as well as from the release of toxic species such as benzene and toluene. The 2015 Shale Oil and Natural Gas Nexus (SONGNex) campaign studied emissions from oil and natural gas activities across the central United States in order to better understand their potential air quality and climate impacts. Here we present VOC measurements from 19 research flights aboard the NOAA WP-3D over 11 shale basins across 8 states. Non-methane hydrocarbons were measured using an improved whole air sampler (iWAS) with post-flight analysis via a custom-built gas chromatograph-mass spectrometer (GC-MS). The whole air samples are complimented by higher-time resolution measurements of methane (Picarro spectrometer), ethane (Aerodyne spectrometer), and VOCs (H3O+ chemical ionization mass spectrometer). Preliminary analysis show that the Permian Basin on the New Mexico/Texas border had the highest observed VOC mixing ratios for all basins studied. We will utilize VOC enhancement ratios to compare the composition of methane and VOC emissions for each basin and the associated reactivities of these gases with the hydroxyl radical, OH, as a proxy for potential ozone formation.

Queen signals in a stingless bee: suppression of worker ovary activation and spatial distribution of active compounds.

PubMed

Nunes, Túlio M; Mateus, Sidnei; Favaris, Arodi P; Amaral, Mônica F Z J; von Zuben, Lucas G; Clososki, Giuliano C; Bento, José M S; Oldroyd, Benjamin P; Silva, Ricardo; Zucchi, Ronaldo; Silva, Denise B; Lopes, Norberto P

2014-12-12

In most species of social insect the queen signals her presence to her workers via pheromones. Worker responses to queen pheromones include retinue formation around the queen, inhibition of queen cell production and suppression of worker ovary activation. Here we show that the queen signal of the Brazilian stingless bee Friesella schrottkyi is a mixture of cuticular hydrocarbons. Stingless bees are therefore similar to ants, wasps and bumble bees, but differ from honey bees in which the queen's signal mostly comprises volatile compounds originating from the mandibular glands. This shows that cuticular hydrocarbons have independently evolved as the queen's signal across multiple taxa, and that the honey bees are exceptional. We also report the distribution of four active queen-signal compounds by Matrix-assisted laser desorption/ionization (MALDI) imaging. The results indicate a relationship between the behavior of workers towards the queen and the likely site of secretion of the queen's pheromones.

Queen signals in a stingless bee: suppression of worker ovary activation and spatial distribution of active compounds

PubMed Central

Nunes, Túlio M.; Mateus, Sidnei; Favaris, Arodi P.; Amaral, Mônica F. Z. J.; von Zuben, Lucas G.; Clososki, Giuliano C.; Bento, José M. S.; Oldroyd, Benjamin P.; Silva, Ricardo; Zucchi, Ronaldo; Silva, Denise B.; Lopes, Norberto P.

2014-01-01

In most species of social insect the queen signals her presence to her workers via pheromones. Worker responses to queen pheromones include retinue formation around the queen, inhibition of queen cell production and suppression of worker ovary activation. Here we show that the queen signal of the Brazilian stingless bee Friesella schrottkyi is a mixture of cuticular hydrocarbons. Stingless bees are therefore similar to ants, wasps and bumble bees, but differ from honey bees in which the queen's signal mostly comprises volatile compounds originating from the mandibular glands. This shows that cuticular hydrocarbons have independently evolved as the queen's signal across multiple taxa, and that the honey bees are exceptional. We also report the distribution of four active queen-signal compounds by Matrix-assisted laser desorption/ionization (MALDI) imaging. The results indicate a relationship between the behavior of workers towards the queen and the likely site of secretion of the queen's pheromones. PMID:25502598

Carbonyl atmospheric reaction products of aromatic hydrocarbons in ambient air

NASA Astrophysics Data System (ADS)

Obermeyer, Genevieve; Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

To convert gaseous carbonyls to oximes during sampling, an XAD-4 resin denuder system pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and followed by analysis with methane positive chemical ionization gas chromatography/mass spectrometry was used to measure carbonyls in ambient air samples in Riverside, CA. In conjunction with similar analyses of environmental chamber OH radical-initiated reactions of o- and p-xylene, 1,2,4-trimethylbenzene, ethylbenzene, 4-hydroxy-2-butanone and 1,4-butanediol, we identified benzaldehyde, o-, m- and p-tolualdehyde and acetophenone and the dicarbonyls glyoxal, methylglyoxal, biacetyl, ethylglyoxal, 1,4-butenedial, 3-hexene-2,5-dione, 3-oxo-butanal, 1,4-butanedial and malonaldehyde in the ambient air samples. As discussed, these carbonyls and dicarbonyls can be formed from the OH radical-initiated reactions of aromatic hydrocarbons and other volatile organic compounds emitted into the atmosphere, and we conclude that in situ atmospheric formation is a major source of these carbonyls in our Riverside, CA, ambient air samples.

Interference of avian guano in analyses of fuel-contaminated soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

James, D.E.; Johnson, T.E.; Kreamer, D.K.

1996-01-01

Site characterization on Johnston Island, Johnston Atoll, Pacific Ocean, has yielded preliminary data that seabird guano can be an interference in three common petroleum hydrocarbon quantification methods. Volatiles from seabird guano were measured on a hydrocarbon-specific handheld vapor meter (catalytic detector) in concentrations as high as 256 ppm by volume total hydrocarbon. Analysis of guano solids produced measurable concentrations of total petroleum hydrocarbon (TPH) as diesel using both an immunoassay test and the EPA 8015 Modified Method. The testing was conducted on one surface sample of guano collected from a seabird roosting and nesting area. Source species were not identified.more » Positive hydrocarbon test results for guano raise concerns regarding the effectiveness of standard methods of petroleum-contaminated site characterization for Johnston island, other Pacific islands, and coastal areas with historic or contemporary seabird populations.« less

Turpentine-induced chemical pneumonitis with broncho-pleural fistula.

PubMed

Rodricks, A; Satyanarayana, M; D'Souza, G A; Ramachandran, P

2003-07-01

Turpentine is a volatile hydrocarbon used in polishes, solvents, paints and textile industry. When hydrocarbons are aspirated into the lung, they cause chemical pneumonitis, acute respiratory distress syndrome (ARDS), and rarely pneumatoceles and pneumothorax. We report a 20-year old boy with turpentine-induced chemical pneumonitis that evolved into a bronchopleural fistula. He was treated with oxygen, steroids and intercostal tube drainage. This is the first reported case of turpentine-associated bronchopleural fistula.

Biotechnological potential for degradation of isoprene: a review.

PubMed

Srivastva, Navnita; Singh, Abhishek; Bhardwaj, Yashpal; Dubey, Suresh Kumar

2018-06-01

Isoprene, the ubiquitous, highly emitted non-methane volatile hydrocarbon, affects atmospheric chemistry and human health, and this makes its removal from the contaminated environment imperative. Physicochemical degradation of isoprene is inefficient and generates secondary pollutants. Therefore, biodegradation can be considered as the safer approach for its efficient abatement. This review summarizes efforts in this regard that led to tracking the diverse groups of isoprene degrading bacteria such as Methanotrophs, Xanthobacter, Nocardia, Alcaligenes, Rhodococcus, Actinobacteria, Alphaproteobacteria, Bacteriodetes, Pseudomonas, and Alcanivorax. Biodegradation of isoprene by such bacteria in batch and continuous modes has been elaborated. The products, pathways and the key enzymes associated with isoprene biodegradation have also been presented.

Impact of pollution controls in Beijing on atmospheric oxygenated volatile organic compounds (OVOCs) during the 2008 Olympic Games: observation and modeling implications

NASA Astrophysics Data System (ADS)

Liu, Y.; Yuan, B.; Li, X.; Shao, M.; Lu, S.; Li, Y.; Chang, C.-C.; Zhu, T.

2014-10-01

Oxygenated volatile organic compounds (OVOCs) are important products of the photo-oxidation of hydrocarbons. They influence the oxidizing capacity and the ozone forming potential of the atmosphere. In the summer of 2008 two months' emission restrictions were enforced in Beijing to improve air quality during the Olympic Games. Observation evidence has been reported in related studies that these control measures were efficient in reducing the concentrations of primary anthropogenic pollutants (CO, NOx and non-methane hydrocarbons, i.e. NMHCs) by 30-40%. In this study, the influence of the emission restrictions on ambient levels of OVOCs was explored using a neural network analysis with consideration of meteorological conditions. Statistically significant reductions in formaldehyde (HCHO), acetaldehyde (CH3CHO), methyl ethyl ketone (MEK) and methanol were found to be 12.9, 15.8, 17.1 and 19.6%, respectively, when the restrictions were in place. The effect of emission control on acetone was not detected in neural network simulations, probably due to pollution transport from surrounding areas outside Beijing. Although the ambient levels of most NMHCs were decreased by ~35% during the full control period, the emission ratios of reactive hydrocarbons attributed to vehicular emissions did not present obvious difference. A zero-dimensional box model based on Master Chemical Mechanism version 3.2 (MCM3.2) was applied to evaluate how OVOCs productions respond to the reduced precursors during the emission controlled period. On average, secondary HCHO was produced from the oxidation of anthropogenic alkenes (54%), isoprene (30%) and aromatics (15%). The importance of biogenic source for the total HCHO formation was almost on a par with that of anthropogenic alkenes during the daytime. Anthropogenic alkenes and alkanes dominated the photochemical production of other OVOCs such as acetaldehyde, acetone and MEK. The relative changes of modelled aldehydes, methyl vinyl ketone and methacrolein (MVK + MACR) before and during the pollution controlled period were comparable to the estimated reductions in the neural network, reflecting that current mechanisms can largely explain secondary production of those species under urban conditions. However, it is worthy to notice that the box model overestimated the measured concentrations of aldehydes by a factor of 1.4-1.7, and simulated MEK was in good agreement with the measurements when primary sources were taken into consideration. These results suggest that the understanding of OVOCs budget in the box model remains incomplete, there is still considerable uncertainty in particular missing sinks (unknown chemical reactions and physical dilution processes) for aldehydes and absence of direct emissions for ketones.

Pilot-scale bioremediation of a petroleum hydrocarbon-contaminated clayey soil from a sub-Arctic site.

PubMed

Akbari, Ali; Ghoshal, Subhasis

2014-09-15

Bioremediation is a potentially cost-effective solution for petroleum contamination in cold region sites. This study investigates the extent of biodegradation of petroleum hydrocarbons (C16-C34) in a pilot-scale biopile experiment conducted at 15°C for periods up to 385 days, with a clayey soil, from a crude oil-impacted site in northern Canada. Although several studies on bioremediation of petroleum hydrocarbon-contaminated soils from cold region sites have been reported for coarse-textured, sandy soils, there are limited studies of bioremediation of petroleum contamination in fine-textured, clayey soils. Our results indicate that aeration and moisture addition was sufficient for achieving 47% biodegradation and an endpoint of 530 mg/kg for non-volatile (C16-C34) petroleum hydrocarbons. Nutrient amendment with 95 mg-N/kg showed no significant effect on biodegradation compared to a control system without nutrient but similar moisture content. In contrast, in a biopile amended with 1340 mg-N/kg, no statistically significant biodegradation of non-volatile fraction was detected. Terminal Restriction Fragment Length Polymorphism (T-RFLP) analyses of alkB and 16S rRNA genes revealed that inhibition of hydrocarbon biodegradation was associated with a lack of change in microbial community composition. Overall, our data suggests that biopiles are feasible for attaining the bioremediation endpoint in clayey soils. Despite the significantly lower biodegradation rate of 0.009 day(-1) in biopile tank compared to 0.11 day(-1) in slurry bioreactors for C16-C34 hydrocarbons, the biodegradation extents for this fraction were comparable in these two systems. Copyright © 2014 Elsevier B.V. All rights reserved.

Headspace solid-phase microextraction coupled to comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for the analysis of aerosol from tobacco heating product.

PubMed

Savareear, Benjamin; Lizak, Radoslaw; Brokl, Michał; Wright, Chris; Liu, Chuan; Focant, Jean-Francois

2017-10-20

A method involving headspace solid-phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was developed and optimised to elucidate the volatile composition of the particulate phase fraction of aerosol produced by tobacco heating products (THPs). Three SPME fiber types were studied in terms of extraction capacity and precision measurements. Divinylbenzene polydimethylsiloxane appeared as the most efficient coating for these measurements. A central composite design of experiment was utilised for the optimization of the extraction conditions. Qualitative and semi-quantitative analysis of the headspace above THP aerosol condensate was carried out using optimised extraction conditions. Semi-quantitative analyses of detected constituents were performed by assuming that their relative response factors to the closest internal standard ( i t R ) were equal to 1. Using deconvoluted mass spectral data (library similarity and reverse match >750) and linear retention indices (match window of ±15 index units), 205 peaks were assigned to individual compounds, 82 of which (including 43 substances previously reported to be present in tobacco) have not been reported previously in tobacco aerosol. The major volatile fraction of the headspace contained ketones, alcohols, aldehydes, alicyclic hydrocarbons alkenes, and alkanes. The method was further applied to compare the volatiles from the particulate phase of aerosol composition of THP with that of reference cigarette smoke and showed that the THP produced a less complex chemical mixture. This new method showed good efficiency and precision for the peak areas and peak numbers from the volatile fraction of aerosol particulate phase for both THP and reference cigarettes. Copyright © 2017 Elsevier B.V. All rights reserved.

Aqueous Oxidation of Green Leaf Volatiles as a Source of Secondary Organic Aerosol

NASA Astrophysics Data System (ADS)

Richards-Henderson, N. K.; Hansel, A.; Pham, A. T.; Vempati, H. S.; Valsaraj, K. T.; Anastasio, C.

2013-12-01

Vegetation emits volatile oxygenated hydrocarbons - the green leaf volatiles (GLVs) - which are formed from the biochemical conversion of linoleic and linolenic acids within plant cells. Stress or damage to vegetation can significantly elevate emission fluxes of these compounds, some of which are fairly water soluble. Aqueous-phase reactions of the GLVs with photochemically generated oxidants - such as hydroxyl radical (OH), singlet oxygen (1O2) and excited triplet states of organic compounds (3C*) _ might then form low-volatility products that can act as secondary organic aerosol (SOA). In order to determine if GLVs can be a significant source of secondary organic carbon in fogwater, studies of GLVs in laboratory solutions are needed to elucidate the oxidation kinetics and the corresponding SOA mass yields. In this study we are determining the second-order rate constants, and SOA mass yields, for five GLVs (cis-3-hexen-1-ol, cis-3-hexenylacetate, methyl salicylate, methyl jasmonate, and 2-methyl-3-butene-2-ol) reacting with OH,1O2 and 3C*. Experiments are performed at relevant fog water pHs, temperatures, and oxidant concentrations. Rate constants are determined using a relative rate approach in which the decay of GLVs and reference compounds are monitored as function of time by HPLC. The capacity of GLVs to form aqueous SOA was determined by following the formation of their decomposition products with HPLC-UV/DAD and HPLC-ESI/MS. SOA mass yields are measured gravimetrically from laboratory solutions containing atmospherically relevant concentrations of photooxidants and GLVs, and irradiated with simulated sunlight. We will use our results to assess the potential contribution of aqueous GLV reactions as a source of SOA in cloudy or foggy atmospheres.

Chemical and biological characterization of products of incomplete combustion from the simulated field burning of agricultural plastic.

PubMed

Linak, W P; Ryan, J V; Perry, E; Williams, R W; DeMarini, D M

1989-06-01

Chemical and biological analyses were performed to characterize products of incomplete combustion emitted during the simulated open field burning of agricultural plastic. A small utility shed equipped with an air delivery system was used to simulate pile burning and forced-air-curtain incineration of a nonhalogenated agricultural plastic that reportedly consisted of polyethylene and carbon black. Emissions were analyzed for combustion gases; volatile, semi-volatile, and particulate organics; and toxic and mutagenic properties. Emission samples, as well as samples of the used (possibly pesticide-contaminated) plastic, were analyzed for the presence of several pesticides to which the plastic may have been exposed. Although a variety of alkanes, alkenes, and aromatic and polycyclic aromatic hydrocarbon (PAH) compounds were identified in the volatile, semi-volatile, and particulate fractions of these emissions, a substantial fraction of higher molecular weight organic material was not identified. No pesticides were identified in either combustion emission samples or dichloromethane washes of the used plastic. When mutagenicity was evaluated by exposing Salmonella bacteria (Ames assay) to whole vapor and vapor/particulate emissions, no toxic or mutagenic effects were observed. However, organic extracts of the particulate samples were moderately mutagenic. This mutagenicity compares approximately to that measured from residential wood heating on a revertant per unit heat release basis. Compared to pile burning, forced air slightly decreased the time necessary to burn a charge of plastic. There was not a substantial difference, however, in the variety or concentrations of organic compounds identified in samples from these two burn conditions. This study highlights the benefits of a combined chemical/biological approach to the characterization of complex, multi-component combustion emissions. These results may not reflect those of other types of plastic that may be used for agricultural purposes, especially those containing halogens.

Catalytic pyrolysis of wheat bran for hydrocarbons production in the presence of zeolites and noble-metals by using TGA-FTIR method.

PubMed

Lazdovica, K; Liepina, L; Kampars, V

2016-05-01

Pyrolysis of wheat bran with or without catalysts was investigated using TGA-FTIR method in order to determine the influence of zeolite and noble metal catalysts on the evolution profile and relative yield of the volatile compounds. The addition of all catalysts decreased the volatile matter of wheat bran from 76.3% to 75.9%, 73.9%, 73.5%, 69.7% and increased the solid residue from 18.0% to 18.4%, 20.4%, 20.8%, 24.6% under the catalyst of ZSM-5, 5% Pd/C, MCM-41, and 5% Pt/C. Noble-metal catalysts had higher activity for deoxygenation of compounds containing carbonyl, carboxyl, and hydroxyl groups than zeolites. Degradation of nitrogen containing compounds atom proceeded better in presence of zeolites. Noble-metal catalysts promoted formation of aromatics and changed the profiles of evolved compounds whereas zeolites advanced formation of aliphatics and olefins. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigation of atmospheric pressure capillary non-thermal plasmas and their applications to the degradation of volatile organic compounds

NASA Astrophysics Data System (ADS)

Yin, Shu-Min

Atmospheric pressure capillary non-thermal plasma (AP-CNTP) has been investigated as a potential technology far the removal of volatile organic compounds (VOCs) in Advanced Life Support Systems (ALS). AP-CNTP is a destructive technology far the removal of VOCs from air streams by active plasma species, such as electrons, ions, and excited molecules. Complete VOC destruction ideally results in the formation of water, carbon dioxide (CO2), and other by-product's may also form, including ozone (O3), nitrous oxide (N2O), nitrogen dioxide (NO2), and decomposed hydrocarbons. Several organic compounds, such as BTEX, ethylene, n-heptane, isooctane, methanol and NH3, were tested in an AP-CNTP system. Parametric experiments were carried out by varying plasma discharge power, flowrates, and initial concentrations. The degradation efficiency varied depending on the chemical nature of the compounds. A plasmochemical kinetic model was derived for toluene, ethylbenzene, and m-xylene and n-heptane.

Potential sources of artifacts and backgrounds generated by the sample preparation of the SAM experiment aboard the Curiosity Rover on Mars

NASA Astrophysics Data System (ADS)

Buch, Arnaud; Belmahdi, Imene; Szopa, Cyril; Freissinet, Caroline; Glavin, Daniel P.; Eigenbrode, Jennifer; Summons, Roger; Miller, Kristen; Coll, Patrice; cabane, Michel; Navarro-Gonzalez, Rafael; Stern, Jennifer; Coscia, David; Teinturier, Samuel; Bonnet, Jean-Yves; Dequaire, Tristan; Mahaffy, Paul; MSL Science Team

2016-10-01

Sample Analysis at Mars (SAM) is one of the instruments of the MSL mission. Three analytical devices are onboard SAM: the Tunable Laser Spectrometer (TLS), the Gas Chromatography (GC) and the Mass Spectrometer (MS). To adapt the nature of a sample to the analytical devices used on SAM, a sample preparation and gas processing system is implemented with (a) a pyrolysis system, (b) wet chemistry: MTBSTFA and TMAH (c) the hydrocarbon trap (silica beads, Tenax® TA and Carbosieve G) which is employed to concentrate volatiles released from the sample prior to GC-MS analysis [1].Volatile compounds and abundant chlorinated hydrocarbons have been detected with SAM when analyzing samples collected in several sites explored by Curiosity rover. Some volatile compounds (chlorinated and non-chlorinated) come from the degradation of the MTBSTFA under high temperature or by the reaction of Martian oxychlorine compounds (present in the samples) with terrestrial carbon coming from the derivatization agent (MTBSTFA) used in SAM [2,3]. But other chlorinated compounds do not follow this pathway. For example, Chlorobenzene has been detected by SAM but it cannot be formed by the reaction of MTBSTFA and perchlorates. Then, two other reaction pathways for chlorobenzene were therefore proposed: (1) reactions between the volatile thermal degradation products of perchlorates (e.g. O2, Cl2 and HCl) and Tenax® and (2) the interaction of perchlorates (T>200°C) with organic material from Mars's soil such as benzenecarboxylates. However, even if major part of the chlorobenzene detected has been identified as Martian origin [4] it is important to list all the potential byproducts able to be released from the Tenax®.Thus, this study inventory all the possible compounds which are originated from Tenax®, MTBSTFA and their interaction with perchlorate.References: [1] Buch, A. et al. (2009) J chrom. A, 43, 143-151. [2] Glavin, D., A. et al. (2013), LPSC. [3] Eigenbrode, J. et al. (2013), LPSC. [4] Freissinet, C. et al., JGR (2015)

Effect of the inclusion of chestnut in the finishing diet on volatile compounds during the manufacture of dry-cured "Lacón" from Celta pig breed.

PubMed

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

2014-01-01

The effect of the finishing diet on the volatile compounds throughout the manufacture of dry-cured "lacón" (a Spanish traditional meat product), from the Celta pig breed was studied. Thirty-six pigs were separated into three groups according to the type of feeding during the finish-fattening period of three months (concentrate, mixed diet and chestnut). From the pigs of each diet, four batches of dry-cured "lacón" were manufactured. From each batch, samples of fresh meat, meat after salting, after post-salting, and after 14, 28, 56 and 84 days of drying-ripening were taken. Volatiles were extracted by a purge-and-trap method and analyzed by gas chromatographic/mass spectrometry (GC/MS). Seventy-six volatile compounds were identified and quantified from dry-cured "lacón" samples in pigs finished with chestnut, eighty-two for concentrate fed pigs and eighty in pigs fed with the mixed diet. The number of identified volatile compounds increased during the manufacturing process; at 84 days of drying-ripening, in the dry-cured "lacón" samples from pigs finished with concentrate, mixed diet and chestnut, 54, 58 and 62 volatile compounds were detected, respectively. The most abundant group of flavour compounds at the end of the manufacturing process was hydrocarbons in the three feeding systems, followed by aldehydes, ketones and alcohols. Discriminant analysis selected six variables (dodecane, butadienol, pentenol, 2-pentenal, decen-3-ona and pyridine-2-methyl) and calculated two discriminating functions which allowed verification of chestnut in the finishing diet. © 2013.

Compound Specific Concentration and Stable Isotope Ratio Measurements of Atmospheric Particulate Organic Matter and Gas Phase Nitrophenols

NASA Astrophysics Data System (ADS)

Busca, R.; Saccon, M.; Moukhtar, S.; Rudolph, J.

2009-05-01

Atmospheric particulate organic matter (POM) adversely affects health and climate. One of the still poorly understood sources of secondary organic matter (SOM) is the formation of secondary POM from the photo- oxidation of atmospheric volatile organic compounds (VOC). Nitrophenols, which are toxic semi-volatile compounds, are formed in the atmosphere by OH-radical initiated photo-oxidation of aromatic hydrocarbons, such as toluene. A method was developed to determine concentrations and stable carbon isotope ratios of particulate methyl nitrophenols in the atmosphere. This method has been used to quantify methyl nitrophenols, specifically 2-methyl-4-nitrophenol and 4-methyl-2-nitrophenol, found in atmospheric PM samples in trace quantities. Using this method, we conducted measurements of methyl nitrophenols in atmospheric PM in rural and suburban areas in Southern Ontario. The results of these measurements showed that the concentration of methyl nitrophenols in atmospheric PM is much lower than expected from the extrapolation of laboratory experiments and measured atmospheric toluene concentrations. In order to better understand the reasons for these findings, an analytical method for the analysis of nitrophenols in the gas phase is currently being developed. Similarly, the measurement technique is modified to allow analysis of other phenolic products of the oxidation of aromatic hydrocarbons in PM as well as in the gas phase. In this poster, sampling techniques for collection and GC-MS analysis of nitrophenols in gas phase and PM will be presented along with preliminary results from summer 2008 and spring 2009 studies.

Similar PAH Fate in Anaerobic Digesters Inoculated with Three Microbial Communities Accumulating Either Volatile Fatty Acids or Methane

PubMed Central

Braun, Florence; Hamelin, Jérôme; Bonnafous, Anaïs; Delgenès, Nadine; Steyer, Jean-Philippe; Patureau, Dominique

2015-01-01

Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH). Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA) production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR), in community structure (SSCP fingerprinting) and in dominant microbial species (454-pyrosequencing). The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10 % to 30 %, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm that PAH removal depends on the molecule type and on the solid matter removal. But, as PAH elimination is similar whether the solid substrate is degraded into VFA or into methane, it seems that the fermentative communities are responsible for their elimination. PMID:25874750

Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

PubMed

Braun, Florence; Hamelin, Jérôme; Bonnafous, Anaïs; Delgenès, Nadine; Steyer, Jean-Philippe; Patureau, Dominique

2015-01-01

Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH). Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA) production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR), in community structure (SSCP fingerprinting) and in dominant microbial species (454-pyrosequencing). The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm that PAH removal depends on the molecule type and on the solid matter removal. But, as PAH elimination is similar whether the solid substrate is degraded into VFA or into methane, it seems that the fermentative communities are responsible for their elimination.

Analysis of large oxygenated and nitrated polycyclic aromatic hydrocarbons formed under simulated diesel engine exhaust conditions (by compound fingerprints with SPE/LC-API-MS)

PubMed Central

Adelhelm, Christoph; Niessner, Reinhard; Pöschl, Ulrich

2008-01-01

The analysis of organic compounds in combustion exhaust particles and the chemical transformation of soot by nitrogen oxides are key aspects of assessment and mitigation of the climate and health effects of aerosol emissions from fossil fuel combustion and biomass burning. In this study we present experimental and analytical techniques for efficient investigation of oxygenated and nitrated derivatives of large polycyclic aromatic hydrocarbons (PAHs), which can be regarded as well-defined soot model substances. For coronene and hexabenzocoronene exposed to nitrogen dioxide under simulated diesel exhaust conditions, several reaction products with high molecular mass could be characterized by liquid chromatography-atmospheric pressure chemical (and photo) ionization-mass spectrometry (LC-APCI-MS and LC-APPI-MS). The main products of coronene contained odd numbers of nitrogen atoms (m/z 282, 256, 338), whereas one of the main products of hexabenzocoronene exhibited an even number of nitrogen atoms (m/z 391). Various reaction products containing carbonyl and nitro groups could be tentatively identified by combining chromatographic and mass spectrometric information, and changes of their relative abundance were observed to depend on the reaction conditions. This analytical strategy should highlight a relatively young technique for the characterization of various soot-contained, semi-volatile, and semi-polar reaction products of large PAHs. Figure LC-APCI-MS analysis of nitrated coronene (and HBC): Total-Ion-Chromatogram (TIC), Extracted Ion Chromatograms (EICs) and corresponding mass spectrum (top). PMID:18560812

Analysis of Volatile Organic Compounds Emitted by Plant Growth-Promoting Fungus Phoma sp. GS8-3 for Growth Promotion Effects on Tobacco

PubMed Central

Naznin, Hushna Ara; Kimura, Minako; Miyazawa, Mitsuo; Hyakumachi, Mitsuro

2013-01-01

We extracted volatile organic compounds (VOCs) emitted by a plant growth-promoting fungus (PGPF) Phoma sp. GS8-3 by gas chromatography and identified them by mass spectrometry. All of the identified compounds belonged to C4-C8 hydrocarbons. Volatiles varied in number and quantity by the culture period of the fungus (in days). 2-Methyl-propanol and 3-methyl-butanol formed the main components of the volatile blends for all the culture periods of fungus. Growth-promoting effects of the identified synthetic compounds were analyzed individually and in blends using tobacco plants. We found that the mixture of volatiles extracted from 3-day-old culture showed significant growth promotion in tobacco in vitro. The volatile blend showed better growth promotion at lower than higher concentrations. Our results confirm the potential role of volatile organic compounds in the mechanism of growth enhancement by GS8-3. PMID:23080408

Volatile components from mango (Mangifera indica L.) cultivars.

PubMed

Pino, Jorge A; Mesa, Judith; Muñoz, Yamilie; Martí, M Pilar; Marbot, Rolando

2005-03-23

The volatile components of 20 mango cultivars were investigated by means of simultaneous distillation-extraction, GC, and GC-MS. Three hundred and seventy-two compounds were identified, of which 180 were found for the first time in mango fruit. The total concentration of volatiles was approximately 18-123 mg/kg of fresh fruit. Terpene hydrocarbons were the major volatiles of all cultivars, the dominant terpenes being delta-3-carene (cvs. Haden, Manga amarilla, Macho, Manga blanca, San Diego, Manzano, Smith, Florida, Keitt, and Kent), limonene (cvs. Delicioso, Super Haden, Ordonez, Filipino, and La Paz), both terpenes (cv. Delicia), terpinolene (cvs. Obispo, Corazon, and Huevo de toro), and alpha-phellandrene (cv. Minin). Other qualitative and quantitative differences among the cultivars could be demonstrated.

Mechanisms involved in cardiac sensitization by volatile anesthetics: general applicability to halogenated hydrocarbons?

PubMed

Himmel, Herbert M

2008-01-01

An increased sensitivity of the heart to catecholamines or cardiac sensitization is a recognized risk during acute human exposure to halogenated hydrocarbons used as solvents, foam-blowing or fire-extinguishing agents, refrigerants, and aerosol propellants. Although cardiac sensitization to such "industrial" halocarbons can result in serious arrhythmia and death, research into its mechanistic basis has been limited, whereas the literature on volatile anesthetics (e.g., halothane, chloroform) is comparably extensive. A review of the literature on halocarbons and related volatile anesthetics was conducted. The available experimental evidence suggests that volatile anesthetics at physiologically relevant concentrations interact predominantly with the main repolarizing cardiac potassium channels hERG and I(Ks), as well as with calcium and sodium channels at slightly higher concentrations. On the level of the heart, inhibition of these ion channels is prone to alter both action potential shape (triangulation) and electrical impulse conduction, which may facilitate arrhythmogenesis by volatile anesthetics per se and is potentiated by catecholamines. Action potential triangulation by regionally heterogeneous inhibition of calcium and potassium channels will facilitate catecholamine-induced afterdepolarizations, triggered activity, and enhanced automaticity. Inhibition of cardiac sodium channels will reduce conduction velocity and alter refractory period; this is potentiated by catecholamines and promotes reentry arrhythmias. Other cardiac and/or neuronal mechanisms might also contribute to arrhythmogenesis. The few scattered in vitro data available for halocarbons (e.g., FC-12, halon 1301, trichloroethylene) suggest inhibition of cardiac sodium (conduction), calcium and potassium channels (triangulation), extraneuronal catecholamine reuptake, and various neuronal ion channels. Therefore, it is hypothesized that halocarbons promote cardiac sensitization by similar mechanisms as volatile anesthetics. Experimental approaches for further investigation of these sensitization mechanisms by selected halocarbons are suggested.

Expectations for Particulate Contamination Relevant to in Situ Atmospheric Sampling for Compositional Analysis at Uranus

NASA Astrophysics Data System (ADS)

Wong, M. H.

2017-12-01

NASA and ESA are considering options for in situ science with atmospheric entry probes to the ice giants Uranus and Neptune. Nominal probe entry mass is in the 300-kg range, although a miniaturized secondary probe option is being studied in the 30-kg range. In all cases, compositional sampling would commence near the 100-mbar level at Uranus, after ejection of the heat shield and deployment of the descent parachute. In this presentation, I review existing literature on the composition, mass loading, and vertical distribution of condensed material that the probe may encounter. Sample inlets for measurement of the gas composition should be heated to avoid potential buildup of condensate, which would block the flow of atmospheric gas into composition sensors. Heating rate and temperature values -- sufficient to keep sample inlets clean under various assumptions -- will be presented. Three main types of condensed material will be considered: Stratospheric hydrocarbon ices: Solar UV photolyzes CH4, leading to the production of volatile hydrocarbons with higher C/H ratios. These species diffuse from their production regions into colder levels where the ices of C2H2, C2H6, and C4H2 condense. Some studies have also considered condensation of C3H8, C4H10, C6H6, and C6H2. Gunk: The hydrocarbon ices are thought to become polymerized due to irradiation from solar UV. The exact composition of the resulting gunk is not known. Solid-state photochemical processing may produce the traces of reddish (blue-absorbing) haze material, present in the troposphere at temperatures warm enough to sublimate the simple hydrocarbon ices. Tropospheric ices: In the region accessible to probes under study (P < 10 bar), much thicker condensation clouds may form from volatile gases CH4, NH3, and H2S. If large amounts of NH3 are sequestered in the deeper H2O liquid cloud, then the S/N ratio could exceed 1 in the probe-accessible region of the atmosphere, leading to NH4SH and H2S ices below the CH4-ice cloud deck. Otherwise, NH4SH and NH3 ices would be found. This work is supported by a grant from the NASA Planetary Science Deep Space Small Satellite Program to the Small Next-generation Atmospheric Probe (SNAP) mission concept study (PI: Kunio Sayanagi).

Synthetic organic compounds and their transformation products in groundwater: occurrence, fate and mitigation.

PubMed

Postigo, Cristina; Barceló, Damià

2015-01-15

Groundwater constitutes the main source of public drinking water supply in many regions. Thus, the contamination of groundwater resources by organic chemicals is a matter of growing concern because of its potential effects on public health. The present manuscript compiles the most recent works related to the study of synthetic organic compounds (SOCs) in groundwater, with special focus on the occurrence of contaminants not or barely covered by previously published reviews, e.g., pesticide and pharmaceutical transformation products, lifestyle products, and industrial chemicals such as corrosion inhibitors, brominated and organophosphate flame retardants, plasticizers, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Moreover, the main challenges in managed aquifer recharge, i.e., reclaimed water injection and infiltration, and riverbank filtration, regarding natural attenuation of organic micropollutants are discussed, and insights into the future chemical quality of groundwater are provided. Copyright © 2014 Elsevier B.V. All rights reserved.

Estimating Biogenic Non-Methane Hydrocarbon Emissions for the Wasatch Front Through a High-Resolution. Gridded, Biogenic Vola Tile Organic Compound Emissions Inventory

DTIC Science & Technology

2002-01-01

1-hour and proposed 8-hour National Ambient Air Quality Standards. Reactive biogenic (natural) volatile organic compounds emitted from plants have...uncertainty in predicting plant species composition and frequency. Isoprene emissions computed for the study area from the project’s high-resolution...Landcover Database (BELD 2), while monoterpene and other reactive volatile organic compound emission rates were almost 26% and 28% lower, respectively

Treatability of volatile chlorinated hydrocarbon-contaminated soils of different textures along a vertical profile by mechanical soil aeration: A laboratory test.

PubMed

Ma, Yan; Shi, Yi; Hou, Deyi; Zhang, Xi; Chen, Jiaqi; Wang, Zhifen; Xu, Zhu; Li, Fasheng; Du, Xiaoming

2017-04-01

Mechanical soil aeration is a simple, effective, and low-cost soil remediation technology that is suitable for sites contaminated with volatile chlorinated hydrocarbons (VCHs). Conventionally, this technique is used to treat the mixed soil of a site without considering the diversity and treatability of different soils within the site. A laboratory test was conducted to evaluate the effectiveness of mechanical soil aeration for remediating soils of different textures (silty, clayey, and sandy soils) along a vertical profile at an abandoned chloro-alkali chemical site in China. The collected soils were artificially contaminated with chloroform (TCM) and trichloroethylene (TCE). Mechanical soil aeration was effective for remediating VCHs (removal efficiency >98%). The volatilization process was described by an exponential kinetic function. In the early stage of treatment (0-7hr), rapid contaminant volatilization followed a pseudo-first order kinetic model. VCH concentrations decreased to low levels and showed a tailing phenomenon with very slow contaminant release after 8hr. Compared with silty and sandy soils, clayey soil has high organic-matter content, a large specific surface area, a high clay fraction, and a complex pore structure. These characteristics substantially influenced the removal process, making it less efficient, more time consuming, and consequently more expensive. Our findings provide a potential basis for optimizing soil remediation strategy in a cost-effective manner. Copyright © 2016. Published by Elsevier B.V.

Low-concentration tailing and subsequent quicklime-enhanced remediation of volatile chlorinated hydrocarbon-contaminated soils by mechanical soil aeration.

PubMed

Ma, Yan; Du, Xiaoming; Shi, Yi; Xu, Zhu; Fang, Jidun; Li, Zheng; Li, Fasheng

2015-02-01

Mechanical soil aeration has long been regarded as an effective ex-situ remediation technique and as suitable for remediation of large-scale sites contaminated by volatile organic compounds (VOCs) at low cost. However, it has been reported that the removal efficiency of VOCs from soil is relatively low in the late stages of remediation, in association with tailing. Tailing may extend the remediation time required; moreover, it typically results in the presence of contaminants residues at levels far exceeding regulations. In this context, the present study aimed to discuss the tailing that occurs during the process of remediation of soils contaminated artificially with volatile chlorinated hydrocarbons (VCHs) and to assess possible quicklime-enhanced removal mechanisms. The results revealed the following conclusions. First, temperature and aeration rate can be important controls on both the timing of appearance of tailing and the levels of residual contaminants. Furthermore, the addition of quicklime to soil during tailing can reduce the residual concentrations rapidly to below the remedial target values required for site remediation. Finally, mechanical soil aeration can be enhanced using quicklime, which can improve the volatilization of VCHs via increasing soil temperature, reducing soil moisture, and enhancing soil permeability. Our findings give a basic understanding to the elimination of the tailing in the application of mechanical soil aeration, particularly for VOCs-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Composition of the electrocautery smoke: integrative literature review].

PubMed

Tramontini, Cibele Cristina; Galvão, Cristina Maria; Claudio, Caroline Vieira; Ribeiro, Renata Perfeito; Martins, Júlia Trevisan

2016-02-01

To identify the composition of the smoke produced by electrocautery use during surgery. Integrative review with search for primary studies conducted in the databases of the US National Library of Medicine National Institutes of Health, Cumulative Index to Nursing and Allied Health Literature, and Latin American and Caribbean Health Sciences, covering the studies published between 2004 and 2014. The final sample consisted of 14 studies grouped into three categories, namely; polycyclic aromatic hydrocarbons, volatile compounds and volatile organic compounds. There is scientific evidence that electrocautery smoke has volatile toxic, carcinogenic and mutagenic compounds, and its inhalation constitutes a potential chemical risk to the health of workers involved in surgeries.

Volatile constituents of Trifolium pratense and T. repens from N.E. Italian alpine pastures.

PubMed

Tava, Aldo; Ramella, Daniele; Grecchi, Maris; Aceto, Paolo; Paoletti, Renato; Piano, Efisio

2009-06-01

The composition of the volatile fraction of two important forage legumes from Italian sub-alpine N.E. pastureland, namely Trifolium pratense L. subsp. pratense (red clover) and T. repens subsp. repens (white clover) were investigated. The volatile oil was obtained from the fresh aerial parts by steam distillation and analyzed by GC/FID and GC/MS. The oil yield was 0.018 and 0.021% (weight/fresh weight basis) for T. pratense and T. repens, respectively. Several classes of compounds were found in both the oils, including alcohols, aldehydes, ketones, terpenes, esters, hydrocarbons, phenolics and acids. Qualitative and quantitative differences were found.

Fates, Budgets, and Health Implications of Macondo Spill Volatile Hydrocarbons in the Ocean and Atmosphere of the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Leifer, I.; Barletta, B.; Blake, D. R.; Blake, N. J.; Bradley, E. S.; Meinardi, S.; Lehr, B.; Luyendyk, B. P.; Roberts, D. A.; Rowland, F. S.

2010-12-01

The Macondo Oil Spill released unprecedented oil and gas to the ocean, estimated at 63000 bbl/day, which dispersed and dissolved during rise (Technical Flow Rate Team Report, 2010); yet, most of the oil reached the sea surface as oil slicks that then evolved due to weathering and dispersant application (Mass Balance Report, 2010). Remote sensing (near infrared imaging spectrometry) allowed quantification of thick surface oil, values of which were incorporated into an overall oil budget calculation. Remote sensing data, atmospheric samples, and numerical modeling, strongly suggest significant volatile loss during rise, yet measured atmospheric concentrations were high. Scaling atmospheric measurements to the total oil spill implies very high, extensive, and persistent levels of atmospheric petroleum hydrocarbon exposure with strong health implications to on-site workers and to coastal residents from wind advection.

Use of headspace sorptive extraction coupled to gas chromatography-mass spectrometry for the analysis of volatile polycyclic aromatic hydrocarbons in herbal infusions.

PubMed

Cacho, J I; Campillo, N; Viñas, P; Hernández-Córdoba, M

2014-08-22

A solvent-free method is described for the determination of 10 volatile polycyclic aromatic hydrocarbons (PAHs), considered as priority pollutants by the EU, in different herbal infusions using headspace sorptive extraction (HSSE) and gas chromatography-mass spectrometry (GC-MS). The parameters affecting both the extraction and thermal desorption steps in the HSSE were optimized by means of Plackett-Burman designs. Ten millilitres of the herbal infusion was submitted to the HSSE preconcentration in the presence of salt for 4h at 88 °C. The use of d(10)-phenanthrene as internal standard not only improved the repeatability of the method but allowed quantification of the samples against external aqueous standards. Detection limits ranged between 11 and 26 ng L(-1). Copyright © 2014 Elsevier B.V. All rights reserved.

[Evolution of technology and occupational exposures in petrochemical industry and in petroleum refining].

PubMed

Cottica, Danilo; Grignani, Elena

2013-01-01

The industry of oil refining and petrochemical play an important role in terms of number of employees in the Italian production. Often the terms "petroleum refining" and "petrochemical" are used interchangeably to define processes that occur in complex plants, which grow outdoors on large surfaces and a visual impact is not irrelevant. In reality, the two areas involve potential exposure to different chemical agents, related to raw materials processed and the specific products. The petrochemical uses as raw materials, the oil fractions, obtained by distillation in the refinery, or natural gas; petrochemical products are, usually, single compounds with a specific degree of purity, used as basic raw materials for the entire industry of organic chemistry, from the production of plastics to pharmaceuticals. The oil refining, that is the topic of this paper, processes mainly oil to obtain mixtures of hydrocarbon compounds, the products of which are specified on the basis of aptitude for use. For example gasolines, are obtained by mixing of fractions of the first distillation, reforming products, antiknock. The paper illustrates, necessarily broadly due to the complexity of the productive sectors, the technological and organizational changes that have led to a significant reduction of occupational exposure to chemical agents, the results of environmental monitoring carried out in some refineries both during routine conditions that during scheduled maintenance activities with plant shutdown and a store of petroleum products. The chemical agents measured are typical for presence, physico-chemical properties and toxicological characteristics of the manufacturing processes of petroleum products like benzene, toluene, xylenes, ethyl benzene, n-hexane, Volatile Hydrocarbons belonging to gasoline, kerosene, diesel fuel. Data related to both personal sampling and fixed positions.

Loss of volatile hydrocarbons from an LNAPL oil source

USGS Publications Warehouse

Baedecker, M.J.; Eganhouse, R.P.; Bekins, B.A.; Delin, G.N.

2011-01-01

The light nonaqueous phase liquid (LNAPL) oil pool in an aquifer that resulted from a pipeline spill near Bemidji, Minnesota, was analyzed for volatile hydrocarbons (VHCs) to determine if the composition of the oil remains constant over time. Oil samples were obtained from wells at five locations in the oil pool in an anaerobic part of the glacial outwash aquifer. Samples covering a 21-year period were analyzed for 25 VHCs. Compared to the composition of oil from the pipeline source, VHCs identified in oil from wells sampled in 2008 were 13 to 64% depleted. The magnitude of loss for the VHCs analyzed was toluene ≫ o-xylene, benzene, C6 and C10–12n-alkanes > C7–C9n-alkanes > m-xylene, cyclohexane, and 1- and 2-methylnaphthalene > 1,2,4-trimethylbenzene and ethylbenzene. Other VHCs including p-xylene, 1,3,5- and 1,2,3-trimethylbenzenes, the tetramethylbenzenes, methyl- and ethyl-cyclohexane, and naphthalene were not depleted during the time of the study. Water–oil and air–water batch equilibration simulations indicate that volatilization and biodegradation is most important for the C6–C9n-alkanes and cyclohexanes; dissolution and biodegradation is important for most of the other hydrocarbons. Depletion of the hydrocarbons in the oil pool is controlled by: the lack of oxygen and nutrients, differing rates of recharge, and the spatial distribution of oil in the aquifer. The mass loss of these VHCs in the 5 wells is between 1.6 and 7.4% in 29 years or an average annual loss of 0.06–0.26%/year. The present study shows that the composition of LNAPL changes over time and that these changes are spatially variable. This highlights the importance of characterizing the temporal and spatial variabilities of the source term in solute-transport models.

Loss of volatile hydrocarbons from an LNAPL oil source.

PubMed

Baedecker, Mary Jo; Eganhouse, Robert P; Bekins, Barbara A; Delin, Geoffrey N

2011-11-01

The light nonaqueous phase liquid (LNAPL) oil pool in an aquifer that resulted from a pipeline spill near Bemidji, Minnesota, was analyzed for volatile hydrocarbons (VHCs) to determine if the composition of the oil remains constant over time. Oil samples were obtained from wells at five locations in the oil pool in an anaerobic part of the glacial outwash aquifer. Samples covering a 21-year period were analyzed for 25 VHCs. Compared to the composition of oil from the pipeline source, VHCs identified in oil from wells sampled in 2008 were 13 to 64% depleted. The magnitude of loss for the VHCs analyzed was toluene≫o-xylene, benzene, C(6) and C(10-12)n-alkanes>C(7)-C(9)n-alkanes>m-xylene, cyclohexane, and 1- and 2-methylnaphthalene>1,2,4-trimethylbenzene and ethylbenzene. Other VHCs including p-xylene, 1,3,5- and 1,2,3-trimethylbenzenes, the tetramethylbenzenes, methyl- and ethyl-cyclohexane, and naphthalene were not depleted during the time of the study. Water-oil and air-water batch equilibration simulations indicate that volatilization and biodegradation is most important for the C(6)-C(9)n-alkanes and cyclohexanes; dissolution and biodegradation is important for most of the other hydrocarbons. Depletion of the hydrocarbons in the oil pool is controlled by: the lack of oxygen and nutrients, differing rates of recharge, and the spatial distribution of oil in the aquifer. The mass loss of these VHCs in the 5 wells is between 1.6 and 7.4% in 29years or an average annual loss of 0.06-0.26%/year. The present study shows that the composition of LNAPL changes over time and that these changes are spatially variable. This highlights the importance of characterizing the temporal and spatial variabilities of the source term in solute-transport models. Published by Elsevier B.V.

Does the volatile hydrocarbon profile differ between the sexes: a case study on five aphidophagous ladybirds.

PubMed

Pattanayak, Rojalin; Mishra, Geetanjali; Omkar; Chanotiya, Chandan Singh; Rout, Prasant Kumar; Mohanty, Chandra Sekhar

2014-11-01

Insect hydrocarbons (HCs) primarily serve as a waterproofing cuticular layer and function extensively in chemical communication by facilitating species, sex, and colony recognition. In this study, headspace solid-phase microextraction is employed for investigating the sex-specific volatile HC profile of five ladybirds collected from Lucknow, India namely, Coccinella septempunctata (L.), Coccinella transversalis (Fabr.), Menochilus sexmaculatus (Fabr.), Propylea dissecta (Mulsant), and Anegleis cardoni (Weise) for the first time. Major compounds reported in C. septempunctata, C. transversalis, and A. cardoni are methyl-branched saturated HCs, whereas in M. sexmaculatus, and P. dissecta, they are unsaturated HCs. Other than A. cardoni, both the sexes of the other four ladybirds had similar compounds at highest peak but with statistically significant differences. However, in A. cardoni, which is a beetle with a narrow niche, the major compound in both male and female was different. The difference in volatile HC profile of the sexes of the five ladybirds indicates that gender-specific differences primarily exist due to quantitative differences in chemicals with only very few chemicals being unique to a gender. This variation in semiochemicals might have a role in behavioral or ecological aspects of the studied ladybirds. © 2014 Wiley Periodicals, Inc.

Assessing the suitability of a manometric test system for determining the biodegradability of volatile hydrocarbons.

PubMed

Brown, David M; Hughes, Christopher B; Spence, Michael; Bonte, Matthijs; Whale, Graham

2018-03-01

Manometric test systems, adapted from those used to measure biochemical oxygen demand (BOD), and the OxiTop ® test system in particular, are being increasingly used to determine the biodegradability of chemicals in accordance to OECD 301F guidelines. In this study, the suitability of the OxiTop ® test system for determining the biodegradability of volatile hydrophobic substances has been explored. Experiments in biotic and abiotic systems were conducted with readily biodegradable complex aliphatic hydrocarbons covering a range of volatilities. Results indicated that abiotic losses of test substances were occurring due to sorption of the test substance to plastic components used in the OxiTop ® system. A further 'plastic-free' biodegradation test system was designed using PreSens optical dissolved oxygen (DO) sensors. This significantly improved the measured biodegradation due to reduced abiotic losses and better retention of the test substance. These results highlight the importance of considering the physico-chemical properties of test substances when selecting test methods and equipment. They also highlight the value of incorporating chemical analysis and abiotic controls to improve the interpretation of biodegradation studies. Copyright © 2017. Published by Elsevier Ltd.

Peripheral neuropathy following intentional inhalation of naphtha fumes.

PubMed Central

Tenenbein, M; deGroot, W; Rajani, K R

1984-01-01

Two adolescent native Canadians who presented with peripheral neuropathy secondary to the abuse of volatile hydrocarbons are described. They were initially thought to have been sniffing leaded gasoline fumes, but public health investigation revealed that they had been sniffing naphtha fumes. Naphtha contains a significant amount of n-hexane, a known inducer of neuropathy. Nerve conduction studies and nerve biopsy confirmed the diagnosis of naphtha abuse. These cases emphasize the need to specifically identify the formulation of hydrocarbons being abused. PMID:6093978

The leaf volatile constituents of Isatis tinctoria by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry.

PubMed

Condurso, Cettina; Verzera, Antonella; Romeo, Vincenza; Ziino, Marisa; Trozzi, Alessandra; Ragusa, Salvatore

2006-08-01

The leaf volatile constituents of Isatis tinctoria L. (Brassicaceae) have been studied by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry (SPME/GC-MS). Seventy components were fully characterized by mass spectra, linear retention indices, and injection of standards; the average composition (ppm) as single components and classes of substances is reported. Aliphatic hydrocarbons, acids, alcohols, aldehydes and esters, aromatic aldehydes, esters and ethers, furans, isothiocyanates and thiocyanates, sulfurated compounds, nitriles, terpenes and sesquiterpenes were identified. Leaf volatiles in Isatis tinctoria L. were characterized by a high amount of isothiocyanates which accounted for about 40 % of the total volatile fraction. Isothiocyanates are important and characteristic flavour compounds in Brassica vegetables and the cancer chemo-protective attributes are recently responsible for their growing interest.

Differences in the fragrances of pollen, leaves, and floral parts of garland (Chrysanthemum coronarium) and composition of the essential oils from flowerheads and leaves.

PubMed

Flamini, Guido; Cioni, Pier Luigi; Morelli, Ivano

2003-04-09

Headspace analyses of pollen, whole flowerheads, ligulate and tubular florets, flower buds, involucral bracts, and leaves have been performed on the food plant Chrysanthemum coronarium L. (Asteraceae). The analyses permitted differences in the pattern of volatiles emitted by the different floral parts to be observed and the site and phenological stage of emission of these chemicals to be verified. Camphor and cis-chrysanthenyl acetate were emitted mainly by ligulate and tubular florets; the production of myrcene and (Z)-ocimene was higher in the flower buds, whereas beta-caryophyllene, (E,E)-alpha-farnesene, and (E)-beta-farnesene seemed attributable mainly to the involucral bracts. The leaves showed a quite different volatile profile, with (Z)-ocimene as the main constituent. Pollen showed a completely different composition of its volatiles, with perilla aldehyde, cis-chrysanthenyl acetate, and camphor among the principal compounds; many carbonylic compounds and linear hydrocarbons have been detected exclusively in pollen. Furthermore, the essential oils obtained from flowerheads and leaves have been studied. These samples showed mainly quantitative differences. Camphor (22.1%) and cis-chrysanthenyl acetate (19.9%) were the main constituents of the oil from flowers, whereas the oil from the leaves contained mainly (Z)-ocimene (45.4%) and myrcene (28.2%).

Carbonyl group containing products from nopinone oxidation

NASA Astrophysics Data System (ADS)

Kahnt, A.; Iinuma, Y.; Heinold, A.; Böge, O.; Herrmann, H.

2010-12-01

Biogenic volatile organic compounds (BVOC) such as isoprene, monoterpenes and sesquiterpenes account for a large fraction of the fluxes of atmospheric non-methane hydrocarbons. Their atmospheric degradation leads to multifunctional oxidation products that can contribute to aerosol growth. In particular, semi-volatile carbonyl compounds that are formed during the early stage of the BVOC oxidation play an important role in the formation of subsequent secondary organic aerosol (SOA) compounds. In this study, a series of aerosol chamber experiments were performed to better understand the OH initiated oxidation of nopinone and subsequent oxidation products in both the gas- and particle-phase. Nopinone is a first generation oxidation product of β-pinene and has been rarely studied for its oxidation products (Calogirou et al., 1999). The gas- and particle-phase products were sampled using a denuder/filter setup. The combination of XAD-4 and 2,4-dinitrophenylhydrazine was applied on the denuder surface to enable in-situ derivatisation of carbonyl compounds. After extraction and sample purification, the derivatised carbonyl compounds were analysed with HPLC/(-)ESI-TOFMS. The data obtained from the denuder sample analysis were compared to the data obtained from the concurrent PTR-MS measurement. The PTR-MS was used in the scan mode during the OH reactions to detect unknown gaseous oxidation products. The selected ion mode was used for some of the experiments to determine the time evolution of certain compounds. The off-line denuder sample analysis enabled us to elucidate the structures of unknown compounds whereas the PTR-MS delivers the time series of oxidation products . The influences of NOx and seed particle acidity on gas- and particle-phase product distributions will be presented. References: A. Calogirou, N.R. Jensen, C.J. Nielsen, D. Kotzias, J. Hjorth, Environmental Science & Technology 33 (1999) 453.

A Comparison of Vascular Effects from Complex and Individual Air Pollutants Indicates a Role for Monoxide Gases and Volatile Hydrocarbons

PubMed Central

Campen, Matthew J.; Lund, Amie K.; Doyle-Eisele, Melanie L.; McDonald, Jacob D.; Knuckles, Travis L.; Rohr, Annette C.; Knipping, Eladio M.; Mauderly, Joe L.

2010-01-01

Background Emerging evidence suggests that the systemic vasculature may be a target of inhaled pollutants of vehicular origin. We have identified several murine markers of vascular toxicity that appear sensitive to inhalation exposures to combustion emissions. Objective We sought to examine the relative impact of various pollutant atmospheres and specific individual components on these markers of altered vascular transcription and lipid peroxidation. Methods Apolipoprotein E knockout (ApoE−/−) mice were exposed to whole combustion emissions (gasoline, diesel, coal, hardwood), biogenically derived secondary organic aerosols (SOAs), or prominent combustion-source gases [nitric oxide (NO), NO2, carbon monoxide (CO)] for 6 hr/day for 7 days. Aortas were assayed for transcriptional alterations of endothelin-1 (ET-1), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-2 (TIMP-2), and heme oxygenase-1 (HO-1), along with measures of vascular lipid peroxides (LPOs) and gelatinase activity. Results We noted transcriptional alterations with exposures to gasoline and diesel emissions. Interestingly, ET-1 and MMP-9 transcriptional effects could be recreated by exposure to CO and NO, but not NO2 or SOAs. Gelatinase activity aligned with levels of volatile hydrocarbons and also monoxide gases. Neither gases nor particles induced vascular LPO despite potent effects from whole vehicular emissions. Conclusions In this head-to-head comparison of the effects of several pollutants and pollutant mixtures, we found an important contribution to vascular toxicity from readily bioavailable monoxide gases and possibly from volatile hydrocarbons. These data support a role for traffic-related pollutants in driving cardiopulmonary morbidity and mortality. PMID:20197249

Volatile Analysis by Pyrolysis of Regolith for Planetary Resource Exploration

NASA Technical Reports Server (NTRS)

Glavin, Daniel P.; Malespin, Charles; ten Kate, Inge L.; Getty, Stephanie A.; Holmes, Vincent E.; Mumm, Erik; Franz, Heather B.; Noreiga, Marvin; Dobson, Nick; Southard, Adrian E.;

The puzzle of HCN in comets: Is it both a product and a primary species?

NASA Astrophysics Data System (ADS)

Mumma, M.; Bonev, B.; Charnley, S.; Cordiner, M.; DiSanti, M.; Gibb, E.; Magee-Sauer, K.; Paganini, L.; Villanueva, G.

2014-07-01

Hydrogen cyanide has long been regarded as a primary volatile in comets, stemming from its presence in dense molecular-cloud cores and its supposed storage in the cometary nucleus. Here, we examine the observational evidence for and against that hypothesis, and argue that HCN may also result from near-nucleus chemical reactions in the coma. The distinction (product vs. primary species) is important for multiple reasons: - HCN is often used as a proxy for water when the dominant species (H_2O) is not available for simultaneous measurement, as at radio wavelengths. If much HCN is sometimes produced in the coma, its adoption as a water proxy could introduce unwanted bias to taxonomies based on composition. - HCN is one of the few volatile carriers of nitrogen accessible to remote sensing, with NH_3 being the dominant nitrile. If HCN is mainly a product species, its precursor becomes the more important metric for compiling a taxonomic classification based on nitrogen chemistry. - The stereoisomer HNC is regarded as a product species, thought to result from coma chemistry involving HCN. But, could another reaction of a primary precursor (X-CN) with a hydrocarbon co-produce both HNC and HCN? - The production rate for CN greatly exceeds the possible production from HCN in some comets, demonstrating the presence of another (more important) precursor of CN radicals in them. - The production rates of HCN measured through rotational (radio) and vibrational (infrared) spectroscopy agree in some comets, but in others the infrared rate exceeds the radio rate substantially. Is prompt emission from vibrationally excited HCN responsible? - With its strong dipole moment and H-bonding character, HCN should be linked more strongly in the nuclear ice to other molecules with similar properties (H_2O, CH_3OH), but instead its spatial release in some comets seems strongly coupled to volatiles that lack a dipole moment and thus do not form H-bonds (methane, ethane). We will present the evidence for and against these points, and suggest ways to test the primary and product origins of cometary HCN.

CHEMISTRY AND PHOTOCHEMISTRY OF LOW-VOLATILITY ORGANIC CHEMICALS ON ENVIRONMENTAL SURFACES

EPA Science Inventory

Hydrophobic organic xenobiotics such as polychlorinated dibenzodioxins and polycyclic aromatic hydrocarbons have strong tendencies to sorb on environmental surfaces. The paper summarizes a workshop in which scientists and modelers assembled to discuss nonbiological processes that...

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY

EPA Science Inventory

The Arizona Border Study, which measured levels of metals, pesticides, polynuclear aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs) in the Arizona counties bordering Mexico, is an extension of the Arizona National Human Exposure Assessment Survey (NHEXAS) Phase...

Resin additive improves performance of high-temperature hydrocarbon lubricants

NASA Technical Reports Server (NTRS)

Johnson, R. L.; Loomis, W. R.

1971-01-01

Paraffinic resins, in high temperature applications, improve strength of thin lubricant film in Hertzian contacts even though they do not increase bulk oil viscosity. Use of resin circumvents corrosivity and high volatility problems inherent with many chemical additives.

Enhancing Isoprene Production by Genetic Modification of the 1-Deoxy-d-Xylulose-5-Phosphate Pathway in Bacillus subtilis▿ †

PubMed Central

Xue, Junfeng; Ahring, Birgitte K.

2011-01-01

To enhance the production of isoprene, a volatile 5-carbon hydrocarbon, in the Gram-positive spore-forming rod-shaped bacterium Bacillus subtilis, 1-deoxy-d-xylulose-5-phosphate synthase (Dxs) and 1-deoxy-d-xylulose-5-phosphate reductoisomerase (Dxr) were overexpressed in B. subtilis DSM 10. For the strain that overexpresses Dxs, the yield of isoprene was increased 40% over that by the wild-type strain. In the Dxr overexpression strain, the level of isoprene production was unchanged. Overexpression of Dxr together with Dxs showed an isoprene production level similar to that of the Dxs overproduction strain. The effects of external factors, such as stress factors including heat (48°C), salt (0.3 M NaCl), ethanol (1%), and oxidative (0.005% H2O2) stress, on isoprene production were further examined. Heat, salt, and H2O2 induced isoprene production; ethanol inhibited isoprene production. In addition, induction and repression effects are independent of SigB, which is the general stress-responsive alternative sigma factor of Gram-positive bacteria. PMID:21296950

Vacuum-based surface modification of organic and metallic substrates

NASA Astrophysics Data System (ADS)

Torres, Jessica

Surface physico-chemical properties play an important role in the development and performance of materials in different applications. Consequently, understanding the chemical and physical processes involved during surface modification strategies is of great scientific and technological importance. This dissertation presents results from the surface modification of polymers, organic films and metallic substrates with reactive species, with the intent of simulating important modification processes and elucidating surface property changes of materials under different environments. The reactions of thermally evaporated copper and titanium with halogenated polytetrafluoroethylene (PTFE) and polyvinyl chloride (PVC) are used to contrast the interaction of metals with polymers. Results indicate that reactive metallization is thermodynamically favored when the metal-halogen bond strength is greater than the carbon-halogen bond strength. X-ray post-metallization treatment results in an increase in metal-halide bond formation due to the production of volatile halogen species in the polymer that react with the metallic overlayer. The reactions of atomic oxygen (AO) and atomic chlorine with polyethylene (PE) and self-assembled monolayers (SAMs) films were followed to ascertain the role of radical species during plasma-induced polymer surface modification. The reactions of AO with X-ray modified SAMs are initially the dominated by the incorporation of new oxygen containing functionality at the vacuum/film interface, leading to the production of volatile carbon containing species such as CO2 that erodes the hydrocarbon film. The reaction of atomic chlorine species with hydrocarbon SAMs, reveals that chlorination introduces C-Cl and C-Cl2 functionalities without erosion. A comparison of the reactions of AO and atomic chlorine with PE reveal a maximum incorporation of the corresponding C-O and C-Cl functionalities at the polymer surface. A novel method to prepare phosphorous-containing polymer surfaces through ion implantation of trimethyl phosphine onto PE is presented. Air exposure of the resulting P-implanted PE leads to the surface selective oxidation of phosphorous moieties. P-containing hydrocarbon films are used to model the surface chemical changes of P-containing polymers exposed to AO. Results indicate that oxidized phosphorous species protect the film from AO-induced erosion. The low temperature (<150 K) oxidation of nitrided iron surfaces exposed to oxygen reveal the formation of iron oxynitride (FexNyO z, nitrosonium ions (NO+) as well as nitrite/nitrito and nitrate type species. The production of nitrite/nitrito and nitrate species is taken as evidence for the existence of oxygen insertion chemistry into the iron nitride lattice under these low temperature oxidation conditions. Upon annealing the oxidized iron nitride surface, nitrogen desorbs exclusively as nitric oxide (NO).

Estimating Emissions of Toxic Hydrocarbons from Natural Gas Production Sites in the Barnett Shale Region of Northern Texas.

PubMed

Marrero, Josette E; Townsend-Small, Amy; Lyon, David R; Tsai, Tracy R; Meinardi, Simone; Blake, Donald R

2016-10-04

Oil and natural gas operations have continued to expand and move closer to densely populated areas, contributing to growing public concerns regarding exposure to hazardous air pollutants. During the Barnett Shale Coordinated Campaign in October, 2013, ground-based whole air samples collected downwind of oil and gas sites revealed enhancements in several potentially toxic volatile organic compounds (VOCs) when compared to background values. Molar emissions ratios relative to methane were determined for hexane, benzene, toluene, ethylbenzene, and xylene (BTEX compounds). Using methane leak rates measured from the Picarro mobile flux plane (MFP) system and a Barnett Shale regional methane emissions inventory, the rates of emission of these toxic gases were calculated. Benzene emissions ranged between 51 ± 4 and 60 ± 4 kg h -1 . Hexane, the most abundantly emitted pollutant, ranged from 642 ± 45 to 1070 ± 340 kg h -1 . While observed hydrocarbon enhancements fall below federal workplace standards, results may indicate a link between emissions from oil and natural gas operations and concerns about exposure to hazardous air pollutants. The larger public health risks associated with the production and distribution of natural gas are of particular importance and warrant further investigation, particularly as the use of natural gas increases in the United States and internationally.

Possible Sources for Methane and C2-C5 Organics in the Plume of Enceladus

NASA Technical Reports Server (NTRS)

McKay, Chris; Khare, Bishun N.; Amin, Ranjamin; Klasson, Martin; Kral, Timothy A.

2012-01-01

In this paper we consider six possible sources of CH4 and other low-mass (C2 - C5) organics in the plume of Enceladus: initial endowments of cometary organics or Titan- like tholin, in situ production by Fisher-Tropsch type reactions, water-rock reactions, or microbiology, and thermogenesis from heavier organics already present. We report on new laboratory results C2 hydrocarbons released on thermogenesis of laboratory tholin and Fisher-Tropsch type synthesis. Tholin heating produced ratios of CH4/C2H4 and CH4/C2H6 of about 2 for temperatures up to 450 C and about 6 for a temperature of 650 C. Low pressure Fisher-Tropsch type experiments produced CH4/C2H4 of approx 1.5, similar to previous results. No C2H2 was produced by either process. Tests of gas production by four strains of methanogens confirmed the absence of any detectable production of non-methane hydrocarbons. Cometary endowment, Fisher-Tropsch type synthesis, and Titan-like tholin incorporation could be primary inputs of organics and subsequent thermal processing of any of these all are possible sources of low mass organics in the plume. Biological production and water-rock reactions are an alternative source of CH4. Neither water-- ]rock reactions or thermal processing of biomass could be a source C2 . C5 organics due to the low interior pressures. The confirmed detection of CO and C2H2 in the plume of Enceladus would provide an important constraint on sources as we have identified no process . other than the initial volatile component of cometary organics which can supply these gases. Precise determination of the relative concentrations of C1 - C5 hydrocarbons may provide additional constraints on sources but a detailed isotopic analysis of C and H in these organics and a search for amino acids constitute the next important steps in resolving the sources of the organics in Enceladus' plume.

VOLATILE ORGANIC CHEMICALS IN 10 PUBLIC-ACCESS BUILDINGS

EPA Science Inventory

The U.S. EPA carried out studies of indoor air quality in 10 buildings. Qualitative analysis identified over 200 aromatics, halogens, esters, alcohols, phenols, ethers, ketones, aldehydes, and epoxides, in addition to several hundred aliphatic hydrocarbons. The total organic load...

Source apportionment of volatile organic compounds measured near a cold heavy oil production area

NASA Astrophysics Data System (ADS)

Aklilu, Yayne-abeba; Cho, Sunny; Zhang, Qianyu; Taylor, Emily

2018-07-01

This study investigated sources of volatile organic compounds (VOCs) observed during periods of elevated hydrocarbon concentrations adjacent to a cold heavy oil extraction area in Alberta, Canada. Elevated total hydrocarbon (THC) concentrations were observed during the early morning hours and were associated with meteorological conditions indicative of gravitational drainage flows. THC concentrations were higher during the colder months, an occurrence likely promoted by a lower mixing height. On the other hand, other VOCs had higher concentrations in the summer; this is likely due to increased evaporation and atmospheric chemistry during the summer months. Of all investigated VOC compounds, alkanes contributed the greatest in all seasons. A source apportionment method, positive matrix factorization (PMF), was used to identify the potential contribution of various sources to the observed VOC concentrations. A total of five factors were apportioned including Benzene/Hexane, Oil Evaporative, Toluene/Xylene, Acetone and Assorted Local/Regional Air Masses. Three of the five factors (i.e., Benzene/Hexane, Oil Evaporative, and Toluene/Xylene), formed 27% of the reconstructed and unassigned concentration and are likely associated with emissions from heavy oil extraction. The three factors associated with emissions were comparable to the available emission inventory for the area. Potential sources include solution gas venting, combustion exhaust and fugitive emissions from extraction process additives. The remaining two factors (i.e., Acetone and Assorted Local/Regional Air Mass), comprised 49% of the reconstructed and unassigned concentration and contain key VOCs associated with atmospheric chemistry or the local/regional air mass such as acetone, carbonyl sulphide, Freon-11 and butane.

Soil pollution by petroleum products, III. Kerosene stability in soil columns as affected by volatilization

NASA Astrophysics Data System (ADS)

Galin, Ts.; Gerstl, Z.; Yaron, B.

1990-05-01

The stability of kerosene in soils as affected by volatization was determined in a laboratory column experiment by following the losses in the total concentration and the change in composition of the residuals in a dune sand, a loamy sand, and a silty loam soil during a 50-day period. Seven major compounds ranging between C 9 and C 15 were selected from a large variety of hydrocarbons forming kerosene and their presence in the remaining petroleum product was determined. The change in composition of kerosene during the experimental period was determined by gas chromatography and related to the seven major compounds selected. The experimental conditions — air-dairy soil and no subsequent addition of water—excluded both biodegradative and leaching. losses. The losses of kerosene in air-dried soil columns during the 50-day experimental period and the changes in the composition of the remaining residues due to volatilization are reported. The volatilization of all the components determined was greater from the dune sand and loamy sand soils than from the silty loam soil. It was assumed that the reason for this behavior was that the dune sand and the loamy sand soils contain a greater proportion of large pores (>4.5 μm) than the silty loam soil, even though the total porosity of the loamy sand and the silty loam is similar. In all the soils in the experiment, the components with a high carbon number formed the main fraction of the kerosene residues after 50 days of incubation.

Biomass Gasification Research and Development Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahring, Birgitte K.

2014-07-22

The overall objective of the BioChemCat project was to demonstrate the feasibility of using Advanced Wet Oxidation Steam-Explosion (AWEx) process to open and solubilize lignocellulosic biomass (LBM) coupled to an innovative mixed culture fermentation technology capable of producing a wide range of volatile fatty acids (VFAs) from all sugars present in LBM. The VFAs will then be separated and converted to hydrocarbon biofuel through catalytic upgrading. By continuously removing VFAs as they are produced (extractive fermentation), we were able to recover the VFAs while both eliminating the need for pH adjustment and increasing the fermentation productivity. The recovered VFAs weremore » then esterified and upgraded to hydrocarbon fuels through a parallel series of hydrogenolysis/decarboxylation and dehydration reactions. We also demonstrated that a portion of the residual lignin fraction was solubilized and converted into VFAs, also improving the yields of VFAs. The remaining lignin fraction was then shown to be available (after dewatering and drying) for use as a lignin-enriched fuel pellet or as a feedstock for further processing.« less

Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

PubMed

Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

2017-04-01

Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

Odabasi, Mustafa

2008-03-01

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

A Three Year Study on 14 VOCs at One Site in Rome: Levels, Seasonal Variations, Indoor/Outdoor Ratio and Temporal Trends

PubMed Central

Fuselli, Sergio; De Felice, Marco; Morlino, Roberta; Turrio-Baldassarri, Luigi

2010-01-01

Fourteen volatile organic compounds (VOCs)—twelve hydrocarbons and two organochlorine compounds—were monitored both outdoors and indoors for three years at one site in Rome. Results showed that 118 out of 168 indoor seasonal mean values were higher than the corresponding outdoor concentrations. The most relevant source of outdoor hydrocarbons was automotive exhaust emissions. Due to the enforcement of various measures to protect health and the environment, outdoor levels of monoaromatic hydrocarbons decreased about ten fold over 15 years, and aliphatic hydrocarbons also decreased. With the decrease in these outdoor concentrations, indoor air sources are likely to be more relevant for indoor air exposures. Winter outdoor values for monoaromatic hydrocarbons were generally markedly higher than the summer ones. The gradual replacement of the current fleet of circulating cars with new cars complying with EURO 5 standards, further reducing hydrocarbon emissions, may possibly lead to an increase in the observed indoor/outdoor ratios. It is indeed more difficult to remove indoor sources, some of which are still unknown. PMID:21139860

Study of aroma formation and transformation during the manufacturing process of Biluochun green tea in Yunnan Province by HS-SPME and GC-MS.

PubMed

Wang, Chen; Lv, Shidong; Wu, Yuanshuang; Lian, Ming; Gao, Xuemei; Meng, Qingxiong

2016-10-01

Biluochun is a typical non-fermented tea and is also famous for its unique aroma in China. Few studies have been performed to evaluate the effect of the manufacturing process on the formation and content of its aroma. The volatile components were extracted at different manufacturing process steps of Biluochun green tea using fully automated headspace solid-phase microextraction (HS-SPME) and further characterised by gas chromatography-mass spectrometry (GC-MS). Among 67 volatile components collected, the fractions of linalool oxides, β-ionone, phenylacetaldehyde, aldehydes, ketones, and nitrogen compounds were increased while alcohols and hydrocarbons declined during the manufacturing process. The aroma compounds decreased the most during the drying steps. We identified a number of significantly changed components that can be used as markers and quality control during the producing process of Biluochun. The drying step played a major role in the aroma formation of green tea products and should be the most important step for quality control. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Effect of γ-irradiation on the physicochemical and sensory properties of hazelnuts ( Corylus avellana L.)

NASA Astrophysics Data System (ADS)

Mexis, S. F.; Kontominas, M. G.

2009-06-01

The present study evaluated the quality of hazelnuts as a function of irradiation dose to determine dose levels causing minimal undesirable changes to hazelnuts. Physicochemical (color, peroxide value (PV), hexanal content, fatty acid composition and volatile compounds) and sensory (color, texture, odor and taste) properties were determined. Results showed a twenty fold increase in peroxide value and twenty-eight fold increase in hexanal content after irradiation at a dose of 7 kGy. An increase was also observed in saturated fatty acids (10%-23%) with a parallel decrease in unsaturated fatty acids (90-77%). Volatile compounds such as ketones, alkanes, alcohols, aldehydes, furans, aromatic hydrocarbons, bicyclic monoterpenes and acids were produced mostly comprising secondary oxidation products of hazelnut lipids after irradiation. Color parameter b* increased ( p<0.05) after irradiation at a dose of ⩾5 kGy, while color parameters L* and a* remained unchanged by irradiation. Sensory evaluation showed that texture and color were not affected by irradiation. Taste, the most sensitive sensory attribute showed that hazelnuts retain acceptable sensory quality when irradiated up to a dose of 1.5 kGy.

IRIS Toxicological Review and Summary Documents for Carbon Tetrachloride (Peer Review Plan)

EPA Science Inventory

Carbon tetrachloride is a volatile haloalkane with a wide range of industrial and chemical applications. It is produced commercially from chlorination of a variety of low molecular weight hydrocarbons such as carbon disulfide, methanol, methane, propane, and ethylene dichloride....

CONTROL OF HYDROCARBON EMISSIONS FROM GASOLINE LOADING BY REFRIGERATION SYSTEMS

EPA Science Inventory

The report gives results of a study of the capabilities of refrigeration systems, operated at three temperatures, to control volatile organic compound (VOC) emissions from truck loading at bulk gasoline terminals. Achievable VOC emission rates were calculated for refrigeration sy...

ENHANCED CONCENTRATION AND ANALYSIS METHOD FOR MEASURING WATER SOLUABLE ENDOGENOUS COMPOUNDS IN HUMAN BREATH

EPA Science Inventory

Exhaled human breath analysis has become a standard technique for assessing exposure to exogenous volatile organic compounds (VOCs) such as trihalomethanes from water chlorination; aromatics, hydrocarbons, and oxygenates from fuels usage; and various chlorinated solvents from i...

OZONE MODULATION OF VOLATILE HYDROCARBONS USING MEMBRANE INTRODUCTION MASS SPECTROMETRY. (R828179)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

DEMONSTRATION BULLETIN: SOILTECH ANAEROBIC THERMAL PROCESSOR: OUTBOARD MARINE CORPORATION SITE

EPA Science Inventory

The ATP system is designed to desorb, collect, and recondense contaminants. The kiln contains four separate internal thermal zones: preheat, retort, combustion, and cooling. In the preheat zone, water and volatile organic compounds are vaporized. Hot solids and heavy hydrocarbons...

Sulfur biogeochemistry of cold seeps in the Green Canyon region of the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Formolo, Michael J.; Lyons, Timothy W.

2013-10-01

Cold seeps in the Gulf of Mexico provide a natural laboratory to study biogeochemical cycling of sulfur, carbon, and oxygen at hydrate- and hydrocarbon-rich deep marine settings with obvious additional relevance to studies of diverse modern and ancient seeps. Of particular interest are the sulfur isotope signatures of microbial sulfate reduction coupled to anaerobic oxidation of methane and other non-methane liquid and gaseous hydrocarbons. Whereas most of the published sulfur isotope data from cold seep systems pertain to pore-water species, our study integrates both solid and dissolved sulfur: acid-volatile sulfides (SAVS), pyrite (Spy), elemental sulfur (S°), dissolved sulfate and ΣH2S. Modeled and 35SO42- reduction rates and δ13C and δ18O data for authigenic carbonates are integrated within this sulfur framework. Our results indicate extreme variability over narrow spatial and temporal scales within short distances (meters) from active seeps. High rates of microbial sulfate reduction can lead to complete consumption of the sulfate within the upper few centimeters of burial, while meters away the sulfate profile shows little depletion. Such small-scale variability must reflect the structure and temporal dynamics of hydrocarbon migration in the presence of low amounts of background organic matter. Our past work demonstrated that electron donors other than methane drive significant levels of microbial activity at these seeps, and very recent work has demonstrated that oxidation of higher chain volatile hydrocarbons can contribute to the high levels of microbial activity. These findings are consistent with our new results. Elevated concentrations of pyrite and diagenetic carbonate relative to background sediments are diagnostic of active seepage, yet the S isotopes tell more complex stories. Low levels of the transient, 'instantaneous' products of S cycling-AVS and S°-show high δ34S values that increase with depth. Most of the pyrite formation, however, seems to be very early as limited by the availability of reactive Fe phases. As such, δ34S values for pyrite at ancient seeps can show consistently low δ34S values that undersell the full intensity of microbial sulfate reduction. Low sedimentation rates, and the resulting low detrital iron fluxes, may in fact limit our ability to recognize seeps in the geologic record using only δ34S compositions for pyrite.

Seasonal variation of the particle size distribution of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in urban aerosol of Guangzhou, China.

PubMed

Tang, X L; Bi, X H; Sheng, G Y; Tan, J H; Fu, J M

2006-06-01

Seasonal aerosol samples have been collected by Andersen Hi-Vol pumping system equipped with a five stage cascade impactor and a backup filter (size range: 10-7.2 microm, 7.2-3.0 microm, 3.0-1.5 microm, 1.5-0.95 microm, 0.95-0.49 microm,

Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale crater, Mars.

PubMed

Ming, D W; Archer, P D; Glavin, D P; Eigenbrode, J L; Franz, H B; Sutter, B; Brunner, A E; Stern, J C; Freissinet, C; McAdam, A C; Mahaffy, P R; Cabane, M; Coll, P; Campbell, J L; Atreya, S K; Niles, P B; Bell, J F; Bish, D L; Brinckerhoff, W B; Buch, A; Conrad, P G; Des Marais, D J; Ehlmann, B L; Fairén, A G; Farley, K; Flesch, G J; Francois, P; Gellert, R; Grant, J A; Grotzinger, J P; Gupta, S; Herkenhoff, K E; Hurowitz, J A; Leshin, L A; Lewis, K W; McLennan, S M; Miller, K E; Moersch, J; Morris, R V; Navarro-González, R; Pavlov, A A; Perrett, G M; Pradler, I; Squyres, S W; Summons, R E; Steele, A; Stolper, E M; Sumner, D Y; Szopa, C; Teinturier, S; Trainer, M G; Treiman, A H; Vaniman, D T; Vasavada, A R; Webster, C R; Wray, J J; Yingst, R A

2014-01-24

H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.

Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale crater, Mars

USGS Publications Warehouse

Ming, D. W.; Archer, P.D.; Glavin, D.P.; Eigenbrode, J.L.; Franz, H.B.; Sutter, B.; Brunner, A.E.; Stern, J.C.; Freissinet, C.; McAdam, A.C.; Mahaffy, P.R.; Cabane, M.; Coll, P.; Campbell, J.L.; Atreya, S.K.; Niles, P.B.; Bell, J.F.; Bish, D.L.; Brinckerhoff, W.B.; Buch, A.; Conrad, P.G.; Des Marais, D.J.; Ehlmann, B.L.; Fairén, A.G.; Farley, K.; Flesch, G.J.; Francois, P.; Gellert, Ralf; Grant, J. A.; Grotzinger, J.P.; Gupta, S.; Herkenhoff, K. E.; Hurowitz, J.A.; Leshin, L.A.; Lewis, K.W.; McLennan, S.M.; Miller, Karl E.; Moersch, J.; Morris, R.V.; Navarro- González, R.; Pavlov, A.A.; Perrett, G.M.; Pradler, I.; Squyres, S. W.; Summons, Roger E.; Steele, A.; Stolper, E.M.; Sumner, D.Y.; Szopa, C.; Teinturier, S.; Trainer, M.G.; Treiman, A.H.; Vaniman, D.T.; Vasavada, A.R.; Webster, C.R.; Wray, J.J.; Yingst, R.A.

2014-01-01

H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.

Characterization of selected volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyl compounds at a roadside monitoring station

NASA Astrophysics Data System (ADS)

Ho, K. F.; Lee, S. C.; Chiu, Gloria M. Y.

Volatile organic compounds (VOCs), PAHs and carbonyl compounds are the major toxic components in Hong Kong. Emissions from motor vehicles have been one of the primary pollution sources in the metropolitan areas throughout Hong Kong for a long time. A 1-yr monitoring program for VOCs, PAHs and carbonyl compounds had been performed at a roadside urban station at Hong Kong Polytechnic University in order to determine the variations and correlations of each selected species (VOCs, PAHs and carbonyl compounds). This study is aimed to analyze toxic volatile organic compounds (benzene, toluene, ethylbenzene and xylene), two carbonyl compounds (formaldehyde, acetaldehyde), and selective polycyclic aromatic hydrocarbons. The monitoring program started from 16 April 1999 to 30 March 2000. Ambient VOC concentrations, many of which originate from the same sources as particulate PAHs and carbonyls compounds, show significant quantities of benzene, toluene and xylenes. Correlations and multivariate analysis of selected gaseous and particulate phase organic pollutants were performed. Source identification by principle component analysis and hierarchical cluster analysis allowed the identification of four sources (factors) for the roadside monitoring station. Factor 1 represents the effect of diesel vehicle exhaust. Factor 2 shows the contribution of aromatic compounds. Factor 3 explains photochemical products—formaldehyde and acetaldehyde. Factor 4 explains the effect of gasoline vehicle exhaust.

Response and potential of agroforestry crops under global change.

PubMed

Calfapietra, C; Gielen, B; Karnosky, D; Ceulemans, R; Scarascia Mugnozza, G

2010-04-01

The use of agroforestry crops is a promising tool for reducing atmospheric carbon dioxide concentration through fossil fuel substitution. In particular, plantations characterised by high yields such as short rotation forestry (SRF) are becoming popular worldwide for biomass production and their role acknowledged in the Kyoto Protocol. While their contribution to climate change mitigation is being investigated, the impact of climate change itself on growth and productivity of these plantations needs particular attention, since their management might need to be modified accordingly. Besides the benefits deriving from the establishment of millions of hectares of these plantations, there is a risk of increased release into the atmosphere of volatile organic compounds (VOC) emitted in large amounts by most of the species commonly used. These hydrocarbons are known to play a crucial role in tropospheric ozone formation. This might represent a negative feedback, especially in regions already characterized by elevated ozone level. 2009 Elsevier Ltd. All rights reserved.

First day of an oil spill on the open sea: early mass transfers of hydrocarbons to air and water.

PubMed

Gros, Jonas; Nabi, Deedar; Würz, Birgit; Wick, Lukas Y; Brussaard, Corina P D; Huisman, Johannes; van der Meer, Jan R; Reddy, Christopher M; Arey, J Samuel

2014-08-19

During the first hours after release of petroleum at sea, crude oil hydrocarbons partition rapidly into air and water. However, limited information is available about very early evaporation and dissolution processes. We report on the composition of the oil slick during the first day after a permitted, unrestrained 4.3 m(3) oil release conducted on the North Sea. Rapid mass transfers of volatile and soluble hydrocarbons were observed, with >50% of ≤C17 hydrocarbons disappearing within 25 h from this oil slick of <10 km(2) area and <10 μm thickness. For oil sheen, >50% losses of ≤C16 hydrocarbons were observed after 1 h. We developed a mass transfer model to describe the evolution of oil slick chemical composition and water column hydrocarbon concentrations. The model was parametrized based on environmental conditions and hydrocarbon partitioning properties estimated from comprehensive two-dimensional gas chromatography (GC×GC) retention data. The model correctly predicted the observed fractionation of petroleum hydrocarbons in the oil slick resulting from evaporation and dissolution. This is the first report on the broad-spectrum compositional changes in oil during the first day of a spill at the sea surface. Expected outcomes under other environmental conditions are discussed, as well as comparisons to other models.

Fatal Diesel Poisoning: A Case Report and Brief Review of Literature.

PubMed

Srinivasa Murthy, Abilash; Das, Siddhartha; Bheemanathi Hanuman, Srinivas

2018-06-01

Hydrocarbons are volatile substances that are used in routine life activities for cooking or as automobile fuel. Diesel is one of the commonly used automobile fuels obtained from crude oil. Death due to poisoning by diesel is rarely reported. Most commonly affected is the respiratory system either after aspiration or ingestion. The most common presentation is chemical pneumonitis or aspiration pneumonitis from which patient usually recovers. Gas chromatography techniques help in the detection of volatile substances like diesel. Here, we report a rare case of fatal pediatric accidental diesel poisoning.

Photochemical Assessment Monitoring Stations (PAMS)

EPA Pesticide Factsheets

Photochemical Assessment Monitoring Stations (PAMS). This file provides information on the numbers and distribution (latitude/longitude) of air monitoring sites which measure ozone precursors (approximately 60 volatile hydrocarbons and carbonyl), as required by the 1990 Clean Air Act Amendments, in areas with persistently high ozone levels (mostly large metropolitan areas). In these areas, the States have established ambient air monitoring sites which collect and report detailed data for volatile organic compounds, nitrogen oxides, ozone and meteorological parameters. This file displays 199 monitoring sites reporting measurements for 2010. A wide range of related monitoring site attributes is also provided.

Volatiles formation in gelled emulsions enriched in polyunsaturated fatty acids during storage: type of oil and antioxidant.

PubMed

Gayoso, Lucía; Poyato, Candelaria; Calvo, María Isabel; Cavero, Rita Yolanda; Ansorena, Diana; Astiasarán, Iciar

2017-08-01

Gelled emulsions with carrageenan are a novel type of emulsion that could be used as a carrier of unsaturated fatty acids in functional foods formulations. Lipid degradation through volatile compounds was studied in gelled emulsions which were high in polyunsaturated oils (sunflower or algae oil) after 49 days of storage. Aqueous Lavandula latifolia extract was tested as a natural antioxidant. Analysis of the complete volatile profile of the samples resulted in a total of 40 compounds, classified in alkanes, alkenes, aldehydes, ketones, acids, alcohols, furans, terpenes and aromatic hydrocarbons. During storage, the formation of the volatile compounds was mostly related to the oxidation of the main fatty acids of the sunflower oil (linolenic acid) and the algae oil (docosahexaenoic acid). Despite the antioxidant capacity shown by the L. latifolia extract, its influence in the oxidative stability in terms of total volatiles was only noticed in sunflower oil gels ( p  < 0.05), where a significant decrease in the aldehydes fraction was found.

Determination of volatile marker compounds in raw ham using headspace-trap gas chromatography.

PubMed

Bosse Née Danz, Ramona; Wirth, Melanie; Konstanz, Annette; Becker, Thomas; Weiss, Jochen; Gibis, Monika

2017-03-15

A simple, reliable and automated method was developed and optimized for qualification and quantification of aroma-relevant volatile marker compounds of North European raw ham using a headspace (HS)-Trap gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detector (FID) analysis. A total of 38 volatile compounds were detected with this HS-Trap GC-MS method amongst which the largest groups were ketones (12), alcohols (8), hydrocarbons (7), aldehydes (6) and esters (3). The HS-Trap GC-FID method was optimized for the parameters: thermostatting time and temperature, vial and desorption pressure, number of extraction cycles and salt addition. A validation for 13 volatile marker compounds with limits of detection in ng/g was carried out. The optimized method can serve as alternative to conventional headspace and solid phase micro extraction methods and allows users to determine volatile compounds in raw hams making it of interest to industrial and academic meat scientists. Copyright © 2016 Elsevier Ltd. All rights reserved.

A chemometrics as a powerful tool in the elucidation of the role of metals in the biosynthesis of volatile organic compounds in Hungarian thyme samples.

PubMed

Arsenijević, Jelena; Marković, Jelena; Soštarić, Ivan; Ražić, Slavica

2013-10-01

The volatile fraction of the leaves of Thymus pannonicus All. (Lamiaceae) was analyzed by headspace extraction followed by GC-FID and GC-MS analysis. The different headspace profiles were recognized, with citral and with monoterpene hydrocarbons as dominant compounds. In addition, the determination of Cr, Co, Ni, Mo, Cu, Zn, Mn, Fe, Mg, Ca, K and Na was conducted by spectroscopic techniques (FAAS, GFAAS and ICP-OES). In order to evaluate the relationship between volatile organic compounds and metals, a chemometrics approach was applied. The data obtained by analysis of the headspace and elemental content were subjected to correlation analysis, factor analysis, principal component analysis and cluster analysis. A number of significant correlations of metals with plant volatiles were found. Correlation of Zn with citral, Mn with oxygenated monoterpenes and Mg with β-bourbonene, could be explained by involvement of metals in the biosynthesis of volatile organic compounds. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

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

PubMed

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

2015-02-01

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

DEMONSTRATION BULLETIN: IN-SITU THERMAL OXIDATION PROCESS - HRUBETZ ENVIRONMENTAL SERVICES

EPA Science Inventory

The HRUBOUT process is a thermal, treatment process designed to remove VOCs and semi-VOCs from contaminated soils. Heated air is injected into the soil below the contamination zone, evaporating soil moisture and removing volatile and semivolatile hydrocarbons. As the water evapor...

Volatile Organic Compounds in Blood as Biomarkers of Exposure to JP-8 Jet Fuel Among US Air Force Personnel.

PubMed

Maule, Alexis L; Proctor, Susan P; Blount, Benjamin C; Chambers, David M; McClean, Michael D

2016-01-01

This study aimed to evaluate blood volatile organic compound (VOC) levels as biomarkers of occupational jet propulsion fuel 8 (JP-8) exposure while controlling for smoking. Among 69 Air Force personnel, post-shift blood samples were analyzed for components of JP-8, including ethylbenzene, toluene, o-xylene, and m/p-xylene, and for the smoking biomarker, 2,5-dimethylfuran. JP-8 exposure was characterized based on self-report and measured work shift levels of total hydrocarbons in personal air. Multivariate regression was used to evaluate the relationship between JP-8 exposure and post-shift blood VOCs while controlling for potential confounding from smoking. Blood VOC concentrations were higher among US Air Force personnel who reported JP-8 exposure and work shift smoking. Breathing zone total hydrocarbons was a significant predictor of VOC blood levels, after controlling for smoking. These findings support the use of blood VOCs as a biomarker of occupational JP-8 exposure.

Organic Geochemistry of Sediments, Interstitial Fluids and Light Volatile Hydrocarbon Gases from Giza and North Alex Mud Volcanoes, Western Nile Deep-Sea Fan

NASA Astrophysics Data System (ADS)

Nuzzo, Marianne; Elvert, Marcus; Heuer, Verena; Schmidt, Mark; Hinrichs, Kai-Uwe; Scholz, Florian; Reitz, Anja; Hensen, Christian

2010-05-01

The West Nile Delta Project is a multi-disciplinary research project lead at IFM-GEOMAR (Kiel, Germany) and funded by RWE-DEA (Hamburg, Germany). It aims at investigating the sources and transport mechanisms of fluids and hydrocarbon gases seeping at two mud volcanoes (MVs) of the western Nile Deep-Sea Fan: North Alex and Giza MVs, and at the long-term monitoring of the seepage activity at these sites [1,2]. A comparative study of the organic geochemistry of sediments, gases and fluids was carried out in order to constrain (i) the sources of fluids, mud and gases erupted at these cold seeps, and (ii) the microbial hydrocarbon-oxidation processes associated with the extrusion of mud and gases. The molecular and stable isotope composition of light volatile hydrocarbon gases stripped from pore fluids reveal a clear thermogenic origin at the less active Giza MV and at the active centre of N. Alex MV. However, they probably originate from different sources, as shown by the distinct 13C-CH4 values of ~ -45‰ and -37‰VPDB at North Alex and Giza MVs, respectively, while 2H-CH4 values are similar (~ -228‰VSMOW). Away from the centre at North Alex MV the gases have variable compositions and are mainly produced by Archaea microbes. The microbial production of CH4 is probably sustained by the high content of the mud breccia sediments in labile organic matter. Indeed Total Organic Carbon content values are high (~ 1 and 2%weight) in MV sediments from both sites as well as at the reference site away from Giza MV, suggesting a main shallow (Plio-Pleistocene) sedimentary source. Consistently, the sedimentary lipids contain high amounts of compounds typically issued from terrestrial plants such as -amyrin and nC26:0 to nC30:0 fatty acids & alkenols. The hypothesis that labile terrestrial organic matter sustains intense microbial activity in the mud volcano sediments is supported by the extreme enrichment of pore fluids in a suite of Volatile Fatty Acids, in particular in acetic acid with values as high as 1 to 2mM at and near the centre of N. Alex MV. Additionally, the lipids extracted from MV sediments contain long-chain n-alkanes and biomarker compounds typically related to the presence of petroleum or bitumen as well as compounds associated with microbial communities living from the Anaerobic Oxidation of Methane. A large variety of these compounds have however been observed at the MVs, and their concentrations are quite variable as well. Here we present the results of multivariate statistical analyses applied to an extensive data set. Complementarily, Compound-Specific-Isotope-Analysis techniques have been used to study the origin of pore water Volatile Fatty Acids and of selected lipid biomarkers at Giza and North Alex MVs. Last, the information provided by geophysical imaging and heat flux measurements performed in the context of the West Nile Delta Project [1] has been taken into account to interpret the complex biogeochemical processes taking place at the MVs. [1] Feseker et al. (2008) RV Poseidon cruise report ISSN 1614-6298, IFM-GEOMAR, Kiel (Germany). [2] Bialas & Brϋckmann (2008) RV Pelagia 64PE298 WND Project cruise report, IFM-GEOMAR, Kiel (Germany), 52p.

Soluble microbial products in pilot-scale drinking water biofilters with acetate as sole carbon source.

PubMed

Zhang, Ying; Ye, Chengsong; Gong, Song; Wei, Gu; Yu, Xin; Feng, Lin

2013-04-01

A comprehensive study on formation and characteristics of soluble microbial products (SMP) during drinking water biofiltration was made in four parallel pilot-scale ceramic biofilters with acetate as the substrate. Excellent treatment performance was achieved while microbial biomass and acetate carbon both declined with the depth of filter. The SMP concentration was determined by calculating the difference between the concentration of dissolved organic carbon (DOC), biodegradable dissolved organic carbon (BDOC) and acetate carbon. The results revealed that SMP showed an obvious increase from 0 to 100 cm depth of the filter. A rising specific ultraviolet absorbance (SUVA) was also found, indicating that benzene or carbonyl might exist in these compounds. SMP produced during this drinking water biological process were proved to have weak mutagenicity and were not precursors of by-products of chlorination disinfection. The volatile parts of SMP were half-quantity analyzed and most of them were dicarboxyl acids, others were hydrocarbons or benzene with 16-17 carbon atoms.

Mitigation of radiation induced surface contamination

DOEpatents

Klebanoff, Leonard E.; Stulen, Richard H.

2003-01-01

A process for mitigating or eliminating contamination and/or degradation of surfaces having common, adventitious atmospheric contaminants adsorbed thereon and exposed to radiation. A gas or a mixture of gases is introduced into the environment of a surface(s) to be protected. The choice of the gaseous species to be introduced (typically a hydrocarbon gas, water vapor, or oxygen or mixtures thereof) is dependent upon the contaminant as well as the ability of the gaseous species to bind to the surface to be protected. When the surface and associated bound species are exposed to radiation reactive species are formed that react with surface contaminants such as carbon or oxide films to form volatile products (e.g., CO, CO.sub.2) which desorb from the surface.

Airborne microbial allergens: Impact and risk assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solomon, W.R.

1990-01-01

Despite their evolution in more natural niches, a variety of microorganisms have also successfully colonized man-made interiors. Such adaptable agents require fairly simple carbon and nitrogen sources, in limited amounts, and find these on surfaces and in fluid collections. Available moisture is also a critical permissive factor. Survival and growth indoors are fostered by the presence of stored biogenic materials and by soiling of surfaces with organic films derived from foodstuffs, soaps, volatile hydrocarbons and organic dusts. Commonly, predators such as protozoa, mites, insects and nematodes graze on a variety of established early invaders so that complex mixed populations aremore » common. At the least, bacteria, fungi and their extracellular products regularly coexist on even marginal substrates.« less

Pedologic Factors Affecting Virgin Olive Oil Quality of "Chemlali" Olive Trees (Olea europaea L.).

PubMed

Rached, Mouna Ben; Galaverna, Gianni; Cirlini, Martina; Boujneh, Dalenda; Zarrouk, Mokhtar; Guerfel, Mokhtar

2017-08-01

The aim of this study examined the characterization of extra virgin olive oil samples from the main cultivar Chemlali, grown in five olive orchards with different soil type (Sandy, Clay, Stony, Brown, Limestone and Gypsum). Volatile compounds were studied using headspace-solid phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) technics. Moreover, the sterol profile was established using gas chromatography-mass spectrometry. 35 different volatile compounds were identified: alcohols, esters, aldehydes, ketones and hydrocarbons. The chemical composition of the volatile fraction was characterized by the preeminence of 2-hexenal (32.75%) and 1-hexanol (31.88%). Three sterols were identified and characterized. For all olive oil samples, ß-sitosterol (302.25 mg/kg) was the most abundant sterol. Interestingly, our results showed significant qualitative and quantitative differences in the levels of the volatile compounds and sterols from oils obtained from olive trees grown in different soil type.

A geochemical investigation into the effect of coal rank on the potential environmental effects of CO2 sequestration in deep coal beds

USGS Publications Warehouse

Kolak, Jonathan J.; Burruss, Robert A.

2005-01-01

Coal samples of different rank were extracted in the laboratory with supercritical CO2 to evaluate the potential for mobilizing hydrocarbons during CO2 sequestration or enhanced coal bed methane recovery from deep coal beds. The concentrations of aliphatic hydrocarbons mobilized from the subbituminous C, high-volatile C bituminous, and anthracite coal samples were 41.2, 43.1, and 3.11 ?g g-1 dry coal, respectively. Substantial, but lower, concentrations of polycyclic aromatic hydrocarbons (PAHs) were mobilized from these samples: 2.19, 10.1, and 1.44 ?g g-1 dry coal, respectively. The hydrocarbon distributions within the aliphatic and aromatic fractions obtained from each coal sample also varied with coal rank and reflected changes to the coal matrix associated with increasing degree of coalification. Bitumen present within the coal matrix may affect hydrocarbon partitioning between coal and supercritical CO2. The coal samples continued to yield hydrocarbons during consecutive extractions with supercritical CO2. The amount of hydrocarbons mobilized declined with each successive extraction, and the relative proportion of higher molecular weight hydrocarbons increased during successive extractions. These results demonstrate that the potential for mobilizing hydrocarbons from coal beds, and the effect of coal rank on this process, are important to consider when evaluating coal beds for CO2 storage.

Volatiles and Nonvolatiles in Flourensia campestris Griseb. (Asteraceae), How Much Do Capitate Glandular Trichomes Matter?

PubMed

Piazza, Leonardo A; López, Daniela; Silva, Mariana P; López Rivilli, Marisa J; Tourn, Mónica G; Cantero, Juan J; Scopel, Ana L

2018-03-01

The distribution and ultrastructure of capitate glandular trichomes (GTs) in Flourensia species (Asteraceae) have been recently elucidated, but their metabolic activity and potential biological function remain unexplored. Selective nonvolatile metabolites from isolated GTs were strikingly similar to those found on leaf surfaces. The phytotoxic allelochemical sesquiterpene (-)-hamanasic acid A ((-)-HAA) was the major constituent (ca. 40%) in GTs. Although GTs are quaternary ammonium compounds (QACs)-accumulating species, glycine betaine was not found in GTs; it was only present in the leaf mesophyll. Two (-)-HAA accompanying surface secreted products: compounds 4-hydroxyacetophenone (piceol; 1) and 2-hydroxy-5-methoxyacetophenone (2), which were isolated and fully characterized (GC/MS, NMR), were present in the volatiles found in GTs. The essential oils of fresh leaves revealed ca. 33% monoterpenes, 26% hydrocarbon- and 30% oxygenated sesquiterpenes, most of them related to cadinene and bisabolene derivatives. Present results suggest a main role of GTs in determining the volatile and nonvolatile composition of F. campestris leaves. Based on the known activities of the compounds identified, it can be suggested that GTs in F. campestris would play key ecological functions in plant-pathogen and plant-plant interactions. In addition, the strikingly high contribution of compounds derived from cadinene and bisabolene pathways, highlights the potential of this species as a source of high-valued bioproducts. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

Detection of semi-volatile organic compounds (SVOCs) in surface water, soil, and groundwater in a chemical industrial park in Eastern China.

PubMed

Liu, Benhua; Li, Yuehua; Ma, Jianfeng; Huang, Linxian; Chen, Liang

2016-01-01

China is suffering from serious water and soil pollution, especially in the North China Plain. This work investigated semi-volatile organic compounds (SVOCs) in surface water, groundwater and soil within a chemical industrial park in Eastern China, for which the volatile organic compound (VOC) results have been previously reported. A total of 20 samples were collected from the field, and analyzed in the laboratory. A 100% detection frequency of SVOCs in samples from this chemical industrial park was observed (same as VOCs). Moreover, the detection frequency of 113 SVOCs in each sample reached 15.93, 12.39 and 20.35% for surface water, groundwater and soil, respectively. The most detected SVOCs in the park included N-containing SVOCs, polycyclic aromatic hydrocarbons, phthalates, organic pesticides and polychlorodiphenyls. The elevated detecting frequencies and concentration levels of SVOCs identified in the groundwater were attributed to the intensive chemical production activities in the park. In addition, the agricultural activities in the area might also have contributed to the SVOCs to the groundwater. The results of VOCs and SVOCs from this and previous studies suggest that the groundwater in this industrial park has been severely contaminated, and the contamination likely spreads beyond the park. Imminent hydrogeological assessments and remedial actions are warranted to eliminate the source and mitigate the potential plume expansion beyond the park boundary.

Fabrication and optimization of a conducting polymer sensor array using stored grain model volatiles.

PubMed

Hossain, Md Eftekhar; Rahman, G M Aminur; Freund, Michael S; Jayas, Digvir S; White, Noel D G; Shafai, Cyrus; Thomson, Douglas J

2012-03-21

During storage, grain can experience significant degradation in quality due to a variety of physical, chemical, and biological interactions. Most commonly, these losses are associated with insects or fungi. Continuous monitoring and an ability to differentiate between sources of spoilage are critical for rapid and effective intervention to minimize deterioration or losses. Therefore, there is a keen interest in developing a straightforward, cost-effective, and efficient method for monitoring of stored grain. Sensor arrays are currently used for classifying liquors, perfumes, and the quality of food products by mimicking the mammalian olfactory system. The use of this technology for monitoring of stored grain and identification of the source of spoilage is a new application, which has the potential for broad impact. The main focus of the work described herein is on the fabrication and optimization of a carbon black (CB) polymer sensor array to monitor stored grain model volatiles associated with insect secretions (benzene derivatives) and fungi (aliphatic hydrocarbon derivatives). Various methods of statistical analysis (RSD, PCA, LDA, t test) were used to select polymers for the array that were optimum for distinguishing between important compound classes (quinones, alcohols) and to minimize the sensitivity for other parameters such as humidity. The performance of the developed sensor array was satisfactory to demonstrate identification and separation of stored grain model volatiles at ambient conditions.

Volatile Compounds in Honey: A Review on Their Involvement in Aroma, Botanical Origin Determination and Potential Biomedical Activities

PubMed Central

Manyi-Loh, Christy E.; Ndip, Roland N.; Clarke, Anna M.

2011-01-01

Volatile organic compounds (VOCs) in honey are obtained from diverse biosynthetic pathways and extracted by using various methods associated with varying degrees of selectivity and effectiveness. These compounds are grouped into chemical categories such as aldehyde, ketone, acid, alcohol, hydrocarbon, norisoprenoids, terpenes and benzene compounds and their derivatives, furan and pyran derivatives. They represent a fingerprint of a specific honey and therefore could be used to differentiate between monofloral honeys from different floral sources, thus providing valuable information concerning the honey’s botanical and geographical origin. However, only plant derived compounds and their metabolites (terpenes, norisoprenoids and benzene compounds and their derivatives) must be employed to discriminate among floral origins of honey. Notwithstanding, many authors have reported different floral markers for honey of the same floral origin, consequently sensory analysis, in conjunction with analysis of VOCs could help to clear this ambiguity. Furthermore, VOCs influence honey’s aroma described as sweet, citrus, floral, almond, rancid, etc. Clearly, the contribution of a volatile compound to honey aroma is determined by its odor activity value. Elucidation of the aroma compounds along with floral origins of a particular honey can help to standardize its quality and avoid fraudulent labeling of the product. Although only present in low concentrations, VOCS could contribute to biomedical activities of honey, especially the antioxidant effect due to their natural radical scavenging potential. PMID:22272147

Volatile Fuel Hydrocarbons and MTBE in the Environment

NASA Astrophysics Data System (ADS)

Cozzarelli, I. M.; Baehr, A. L.

2003-12-01

Petroleum hydrocarbons (hydrocarbons that result from petroleum products such as oil, gasoline, or diesel fuel) are among the most commonly occurring and widely distributed contaminants in the environment. Volatile hydrocarbons are the lighter fraction of the petroleum hydrocarbons and, together with fuel oxygenates, are most often released from crude oil and liquid petroleum products produced from crude oil. The demand for crude oil stems from the world's ever-growing energy need. From 1970 to 1999, primary energy production of the world grew by 76% (Energy Information Administration, 2001), with fossil fuels (crude oil, natural gas, and coal) accounting for ˜85% of all energy produced worldwide (Figure 1). World crude oil production reached a record 68 million barrels (bbl) per day (1.08×1010 L d-1) in 2000. The world's dependence on oil as an energy source clearly is identified as contributing to global warming and worsening air and water quality. (7K)Figure 1. World primary energy production by source from 1970 to 1999 (Energy Information Administration, 2001). Petroleum products are present in Earth's subsurface as solids, liquids, or gases. This chapter presents a summary of the environmental problems and issues related to the use of liquid petroleum, or oil. The focus is on the sources of volatile hydrocarbons and fuel oxygenates and the geochemical behavior of these compounds when they are released into the environment. Although oxygenates currently in commercial use include compounds other than methyl t-butyl ether (MTBE), such as ethanol (ETOH), most of the information presented here focuses on MTBE because of its widespread occurrence. The environmental impact of higher molecular weight hydrocarbons that also originate from petroleum products is described in (Chapter 9.13, Abrajano et al.).Crude oil occurs within the Earth and is a complex mixture of natural compounds composed largely of hydrocarbons containing only hydrogen and carbon atoms. The minor elements of sulfur, nitrogen, and oxygen constitute less than 3% of most petroleum (Hunt, 1996). Releases to the environment occur during the production, transport, processing, storage, use and disposal of these hydrocarbons. The petroleum industry classifies oil naturally occurring in a liquid phase as either conventional oil or nonconventional oil. Conventional oils can be explored and produced by conventional primary and secondary recovery techniques, whereas nonconventional oils, such as heavy oils, tar sands, and synthetic oils, are more difficult to extract from the host rock ( Tissot and Welte, 1984). The history of liquid petroleum usage dates back centuries. Marco Polo described its use as a fuel for lamps in 1291 ( Testa and Winegardner, 2000). In the mid-nineteenth century, Native Americans used crude oil skimmed from creeks and rivers as a medicinal ointment ( Energy Information Administration, 1999). Commercial production in the United States began in 1859, with kerosene production for use in lamps. At the turn of the century, emphasis shifted to gasoline with the invention of the automobile, and in the 1930s and 1940s a substantial market for heating oil developed.In 2000, over 85% of the world's energy came from fossil fuels (Table 1), with oil production alone supplying 40% of that energy (Edwards, 2001). Oil, with its high British Thermal Unit (BTU) density and ease of transport, is the most valuable fuel in the world today, and the demand for world crude oil is ever increasing. Annual world crude-oil demand increased from 22 billion to 28 billion bbl of oil (BBO) ((3.5-4.5)×1012 L) from 1990 to 2000. Increasing population growth and industrialization in developing countries is expected to drive this annual oil demand up 1.5% annually to ˜38 BBO (6.0×1012 L) by 2030. As demand increases and known oil reserves are depleted, more emphasis will be placed on new discoveries and improved recovery technologies. Sources such as tar sands and oil shales are likely to become more important, bringing environmental problems inherent to the production, transport, and processing of these resources to new sectors of the environment. Table 1. United States and world energy consumption by source (January 2000) Energy SourceUnited StatesWorld BBOEPercentBBOEPercent Petroleum6.84127.140 Natural gas4.224.214.421.2 Coal3.923.216.724.7 Nuclear1.37.94.56.7 Hydroelectric0.733.71.62.4 Biomass3.45 Total7.610069.3100 Source: Edwards (2001). BBOE=billion barrels of oil equivalent. Reserves of crude oil, the raw material used to make petroleum products, are not evenly distributed around the world. The production levels of the major oil-producing nations in the world, shown in Figure 2, are based on data collected by the US Department of Energy's (DOEs) Energy Information Administration (EIA). Nations in the Organization of Petroleum Exporting Countries (OPEC) produce ˜43% of the world's total of nearly 68 million bbl per day (bpd) (1.08×1010 L d-1), with Saudi Arabia as the world's largest producer at 8.3 million bpd (12% of total) (1.33×109 L d-1), followed by Russia and the former Soviet Union at 6.4 million bpd (9%) (1.02×109 L d-1). The United States produced ˜5.7 million bpd (8%) (9.06×108 L d-1). Oil and gas are being produced in virtually all geographic areas intersecting a wide range of ecological habitats, including tropical rain forests, Middle Eastern deserts, Arctic regions, and deep offshore marine environments. (6K)Figure 2. World crude-oil production from leading producers, 1960-2000, in million barrels per day (Energy Information Administration, 2001). The petroleum industry has two main components, exploration/recovery and refinement/delivery. Crude oil is delivered to refineries and refined products are delivered to consumers through a large transportation network that includes tankers, barges, pipelines, and railroads. This transportation network links suppliers and producers across the world. Above-ground tanks, below-ground tanks and caverns, and offshore facilities store petroleum at various stages in this distribution system. The largest underground storage facilities in the US are part of the US. Strategic Petroleum Reserve maintained by the US government for times of supply shortage (Energy Information Administration, 1999). The global and complex nature of this industry means that every environmental compartment (air, land, water, biota) and all nations are affected by petroleum spills and waste products.Petroleum products are released into the environment inadvertently and intentionally at all stages of petroleum use, from exploration, production, transportation, storage, use and disposal (Figure 3). The more volatile components of oil partition preferentially into the atmosphere and hydrosphere, and to a lesser extent, the geosphere (e.g., sorption onto sediments), and biosphere (i.e., bioaccumulation), whereas the higher molecular weight fraction of oil is less soluble and less volatile and impacts the biosphere and geosphere more directly as described by Abrajano et al. (see Chapter 9.13). Usage causes compounds from petroleum products to separate and enter the environment. For example, incomplete fuel combustion in an automobile engine or a home heating furnace results in the release of compounds to the atmosphere, where they can be widely dispersed. Compounds in the exhaust gas of a motor boat partition in river or lake water, allowing for mixing and transport in the water body. These examples are illustrative of chronic low-level and widespread release of compounds referred to as nonpoint sources. (10K)Figure 3. Modes of contamination by petroleum products during production, transport, use, and disposal (after Fetter, 1993). Concentrated releases of compounds to the environment generally are associated with product mishandling and accidents during storage and transportation. For example, gasoline leaking from an underground storage tank (UST) releases compounds to the air, water, and solids of the subsurface. An oil tanker spill at sea can result in the rapid dispersal of large amounts of product. These two examples of more concentrated release are referred to as point sources. However, in the case of a tanker spill, the point release can result in a serious regional problem such as the spill of the Exxon Valdez that spilled oil that spread 750 km from the original spill site and impacted 1,750 km of shoreline (Wolfe et al., 1994).Nonpoint sources can cause compounds to be dispersed throughout the hydrosphere, which can complicate efforts to evaluate the effect of spills. Current sampling and analytical techniques allow for the detection of volatile organic compounds (VOCs) at low concentrations (0.1 μg L-1 and less). As a result, VOCs have been detected frequently in ambient shallow groundwater in urban areas across the country in studies conducted as part of the US Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program (Squillace et al., 1996). The importance of VOCs at low concentrations in ambient water is unclear. If these low concentrations are the result of plumes emanating from point sources, then concentrations could possibly increase with time. If the source were diffuse (nonpoint), as in the case of atmospheric sources, then changes in VOC concentrations in groundwater over time would be constrained by atmospheric concentrations.Widely distributed and frequent point source spills can be considered nonpoint sources when the scale of concern is large in space or time. For example, the United States generates 1.3 billion gallons (4.9×109 L) of used motor oil each year, of which ˜13% is disposed of improperly (Motor Oil Facts, http://www.epa.gov/seahome/housewaste/src/oilfact.htm). This large quantity of improperly disposed motor oil could be a regional source of MTBE and benzene, toluene, ethylbenzene, and xylenes (BTEX) as used motor oil contains BTEX and MTBE, ˜500-2,000 mg L-1 for BTEX and 100 mg L-1 for MTBE (Baker et al., 2002; Chen et al., 1994). In a survey of 946 domestic wells designed to assess ambient groundwater quality in Maine, MTBE was detected in 15.8% of the wells, mostly at concentrations less than 0.1 μg L-1 (State of Maine Bureau of Health, 1998). Small and widely distributed spills of fuel-related products not necessarily associated with leaking storage tanks were identified as likely sources.

Quantifying Marine Emissions of Biogenic Volatile Organic Compounds Using Laboratory Measurements of Plankton Monocultures and Field Samples

NASA Astrophysics Data System (ADS)

Sabolis, A. W.; Meskhidze, N.; Kamykowski, D.; Reed, R. E.

2010-12-01

Marine biogenic volatile organic compounds (BVOCs) have been suggested to contribute significant portion of the organic carbon present in ocean atmosphere. In this study emission rates of 40 different hydrocarbons are quantified for lab-grown non-axenic phytoplankton monocultures and ambient samples from the Pamlico-Neuse Estuary, NC. The outcome of environmental conditions on production of BVOCs was examined for different light and temperature conditions. These different regimes are considered proxies for physiological stress-induced effects observed in natural ecosystems. The samples were incubated in a climate controlled room; they were then transferred to smaller volumes (200 ml) for analysis. BVOCs accumulated in the water and headspace above the water were measured by bubbling hydrocarbon-free gas mixture through the sample and passing the gas stream through a gas chromatography/mass spectrometry system equipped with a sample pre-concentrator. Inside the pre-concentrator, the compounds were trapped on a sorbent material, heated, and flushed into the GC-MS column. The pre-concentrator/GC-MS system gave at least 1000 times magnification of the sample concentrations, allowing detection of low ppt levels of hydrocarbons. Here we report results for lab-grown diatoms Thalassiosira weissflogii and Thalassiosira pseudonana, prymnesiophyte Pleurochrysis carterae, and dinoflagellates Karina brevis and Procentrum minimum, as well as field samples. To make results widely usable, all the emissions are normalized to Chlorophyll-a (Chl-a) concentration and cell counts. Our results show that diatoms had the highest isoprene production rate of 2.8 μmol (g Chl-a)-1 h-1 with ranges between 1.4 and 3.6 μmol (g Chl-a)-1 h-1 at light levels between 90 and 900 μE m-2 s-1, respectively. The prymnesiophyte and dinoflagellate species had isoprene production rates of 1.3±0.4 μmol (g Chl-a)-1 h-1 with a similar light dependency as diatoms. Field samples had comparable isoprene production rate of 3.5 μmol (g Chl-a)-1 h-1 with ranges between 0.6 and 4.1 μmol (g Chl-a)-1 h-1 for similar light levels and temperatures between 18 to 30°C. Three monoterpenes detected were α-pinene, camphene, and d-limonene. Diatoms had the highest α-pinene and d-limonene production rates of 0.045 μmol (g Chl-a)-1 h-1 and 0.015 μmol (g Chl-a)-1 h-1, respectively. The prymnesiophyte species had the highest camphene production of 0.021 μmol (g Chl-a)-1 h-1. Production rates of d-limonene and camphene did not show a well-defined light dependency, but both isoprene and α-pinene showed an increase in terpene production with increasing light intensities. Field samples show α-pinene, d-limonene, and camphene production rates of 0.05 μmol (g Chl-a)-1 h-1, 0.02 μmol (g Chl-a)-1 h-1 and 0.018 μmol (g Chl-a)-1 h-1, respectively. Field samples acclimated at 26°C had the highest terpene production rates. This study tabulates a large number of BVOC emission rates for various phytoplankton species under diverse environmental conditions.

Diesel particle filter and fuel effects on heavy-duty diesel engine emissions.

PubMed

Ratcliff, Matthew A; Dane, A John; Williams, Aaron; Ireland, John; Luecke, Jon; McCormick, Robert L; Voorhees, Kent J

2010-11-01

The impacts of biodiesel and a continuously regenerated (catalyzed) diesel particle filter (DPF) on the emissions of volatile unburned hydrocarbons, carbonyls, and particle associated polycyclic aromatic hydrocarbons (PAH) and nitro-PAH, were investigated. Experiments were conducted on a 5.9 L Cummins ISB, heavy-duty diesel engine using certification ultra-low-sulfur diesel (ULSD, S ≤ 15 ppm), soy biodiesel (B100), and a 20% blend thereof (B20). Against the ULSD baseline, B20 and B100 reduced engine-out emissions of measured unburned volatile hydrocarbons and PM associated PAH and nitro-PAH by significant percentages (40% or more for B20 and higher percentage for B100). However, emissions of benzene were unaffected by the presence of biodiesel and emissions of naphthalene actually increased for B100. This suggests that the unsaturated FAME in soy-biodiesel can react to form aromatic rings in the diesel combustion environment. Methyl acrylate and methyl 3-butanoate were observed as significant species in the exhaust for B20 and B100 and may serve as markers of the presence of biodiesel in the fuel. The DPF was highly effective at converting gaseous hydrocarbons and PM associated PAH and total nitro-PAH. However, conversion of 1-nitropyrene by the DPF was less than 50% for all fuels. Blending of biodiesel caused a slight reduction in engine-out emissions of acrolein, but otherwise had little effect on carbonyl emissions. The DPF was highly effective for conversion of carbonyls, with the exception of formaldehyde. Formaldehyde emissions were increased by the DPF for ULSD and B20.

Volatile organic compounds and isoprene oxidation products at a temperate deciduous forest site

NASA Astrophysics Data System (ADS)

Helmig, Detlev; Greenberg, Jim; Guenther, Alex; Zimmerman, Pat; Geron, Chris

1998-09-01

Biogenic volatile organic compounds (BVOCs) and their role in atmospheric oxidant formation were investigated at a forest site near Oak Ridge, Tennessee, as part of the Nashville Southern Oxidants Study (SOS) in July 1995. Of 98 VOCs detected, a major fraction were anthropogenic VOCs such as chlorofluorocarbons (CFCs), alkanes, alkenes and aromatic compounds. Isoprene was the dominant BVOC during daytime. Primary products from BVOC oxidation were methylvinylketone, methacrolein and 3-methylfuran. Other compounds studied include the BVOCs α-pinene, camphene, β-pinene, p-cymene, limonene and cis-3-hexenyl acetate and a series of light alkanes, aromatic hydrocarbons and seven of the CFCs. The correlation of meteorological parameters, with the mixing ratios of these different compounds, reveals information on atmospheric oxidation processes and transport. Long-lived VOCs show very steady mixing ratio time series. Regionally and anthropogenically emitted VOCs display distinct diurnal cycles with a strong mixing ratio decrease in the morning from the breakup of the nocturnal boundary layer. Nighttime mixing ratio increases of CFCs and anthropogenic VOCs are suspected to derive from emissions within the Knoxville urban area into the shallow nocturnal boundary layer. In contrast, the time series of BVOCs and their oxidation products are determined by a combination of emission control, atmospheric oxidation and deposition, and boundary layer dynamics. Mixing ratio time series data for monoterpenes and cis-3-hexenyl acetate suggest a temporarily emission rate increase during and after heavy rain events. The isoprene oxidation products demonstrate differences in the oxidation pathways during night and day and in their dry and wet deposition rates.

Primary and secondary sources of formaldehyde in urban atmospheres: Houston Texas region

NASA Astrophysics Data System (ADS)

Parrish, D. D.; Ryerson, T. B.; Mellqvist, J.; Johansson, J.; Fried, A.; Richter, D.; Walega, J. G.; Washenfelder, R. A.; de Gouw, J. A.; Peischl, J.; Aikin, K. C.; McKeen, S. A.; Frost, G. J.; Fehsenfeld, F. C.; Herndon, S. C.

2011-12-01

We evaluate the rates of secondary production and primary emission of formaldehyde (CH2O) from petrochemical industrial facilities and on-road vehicles in the Houston Texas region. This evaluation is based upon ambient measurements collected during field studies in 2000, 2006 and 2009. The predominant CH2O source (92 ± 4% of total) is secondary production formed during the atmospheric oxidation of highly reactive volatile organic compounds (HRVOCs) emitted from the petrochemical facilities. Smaller contributions are primary emissions from these facilities (4 ± 2%), and secondary production (~3%) and primary emissions (~1%) from vehicles. The primary emissions from both sectors are well quantified by current emission inventories. Since secondary production dominates, control efforts directed at primary CH2O emissions cannot address the large majority of CH2O sources in the Houston area, although there may still be a role for such efforts. Ongoing efforts to control alkene emissions from the petrochemical facilities, as well as volatile organic compound emissions from the motor vehicle fleet, will effectively reduce the CH2O concentrations in the Houston region. We have not addressed other emission sectors, such as off-road mobile sources or secondary formation from biogenic hydrocarbons. Previous analyses based on correlations between ambient concentrations of CH2O and various marker species have suggested much larger primary emissions of CH2O, but those results neglect confounding effects of dilution and loss processes, and do not demonstrate the causes of the observed correlations. Similar problems must be suspected in any source apportionment analysis of secondary species based upon correlations of ambient concentrations of pollutants.

Primary and secondary sources of formaldehyde in urban atmospheres: Houston Texas region

NASA Astrophysics Data System (ADS)

Parrish, D. D.; Ryerson, T. B.; Mellqvist, J.; Johansson, J.; Fried, A.; Richter, D.; Walega, J. G.; Washenfelder, R. A.; de Gouw, J. A.; Peischl, J.; Aikin, K. C.; McKeen, S. A.; Frost, G. J.; Fehsenfeld, F. C.; Herndon, S. C.

2012-04-01

We evaluate the rates of secondary production and primary emission of formaldehyde (CH2O) from petrochemical industrial facilities and on-road vehicles in the Houston Texas region. This evaluation is based upon ambient measurements collected during field studies in 2000, 2006 and 2009. The predominant CH2O source (92 ± 4% of total) is secondary production formed during the atmospheric oxidation of highly reactive volatile organic compounds (HRVOCs) emitted from the petrochemical facilities. Smaller contributions are primary emissions from these facilities (4 ± 2%), and secondary production (~3%) and primary emissions (~1%) from vehicles. The primary emissions from both sectors are well quantified by current emission inventories. Since secondary production dominates, control efforts directed at primary CH2O emissions cannot address the large majority of CH2O sources in the Houston area, although there may still be a role for such efforts. Ongoing efforts to control alkene emissions from the petrochemical facilities, as well as volatile organic compound emissions from the motor vehicle fleet, will effectively reduce the CH2O concentrations in the Houston region. We do not address other emission sectors, such as off-road mobile sources or secondary formation from biogenic hydrocarbons. Previous analyses based on correlations between ambient concentrations of CH2O and various marker species have suggested much larger primary emissions of CH2O, but those results neglect confounding effects of dilution and loss processes, and do not demonstrate the causes of the observed correlations. Similar problems must be suspected in any source apportionment analysis of secondary species based upon correlations of ambient concentrations of pollutants.

Engineering limonene and bisabolene production in wild type and a glycogen-deficient mutant of Synechococcus sp. PCC 7002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davies, Fiona K.; Work, Victoria H.; Beliaev, Alex S.

2014-06-19

The plant terpenoids limonene (C10H16) and α-bisabolene (C15H24) are hydrocarbon precursors to a range of industrially-relevant chemicals. High-titer microbial synthesis of limonene and α- bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. We have engineered the fast-growing unicellular euryhaline cyanobacterium Synechococcus sp. PCC 7002 to produce yields of 4 mg L-1 limonene and 0.6 mg L-1 α-bisabolene through heterologous expression of the Mentha spicata L-limonene synthase or the Abies grandis (E)-α-bisabolene synthase genes, respectively. Titers were significantly higher when a dodecane overlay was applied during culturing, suggesting either thatmore » dodecane traps large quantities of volatile limonene and α-bisabolene that would otherwise be lost to evaporation, and/or that continuous product removal in dodecane alleviates product feedback inhibition to promote higher rates of synthesis. We also investigate limonene and bisabolene production in the ΔglgC genetic background, where carbon partitioning is redirected at the expense of glycogen biosynthesis. The Synechococcus sp. PCC 7002 ΔglgC mutant excreted a suite of overflow metabolites (α-ketoisocaproate, pyruvate, α-ketoglutarate, succinate and acetate) during nitrogen deprivation, and also at the onset of stationary growth in nutrient-replete media. None of the excreted metabolites, however, appeared to be effectively utilized for terpenoid metabolism. Interestingly, we observed a 1.6 to 2.5-fold increase in the extracellular concentration of most excreted organic acids when the ΔglgC mutant was conferred with the ability to produce limonene. Overall, Synechococcus sp. PCC 7002 provides a highly promising platform for terpenoid biosynthetic and metabolic engineering efforts.« less

Engineering Limonene and Bisabolene Production in Wild Type and a Glycogen-Deficient Mutant of Synechococcus sp. PCC 7002.

PubMed

Davies, Fiona K; Work, Victoria H; Beliaev, Alexander S; Posewitz, Matthew C

2014-01-01

The plant terpenoids limonene (C10H16) and α-bisabolene (C15H24) are hydrocarbon precursors to a range of industrially relevant chemicals. High-titer microbial synthesis of limonene and α-bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. We have engineered the fast-growing unicellular euryhaline cyanobacterium Synechococcus sp. PCC 7002 to produce yields of 4 mg L(-1) limonene and 0.6 mg L(-1) α-bisabolene through heterologous expression of the Mentha spicatal-limonene synthase or the Abies grandis (E)-α-bisabolene synthase genes, respectively. Titers were significantly higher when a dodecane overlay was applied during culturing, suggesting either that dodecane traps large quantities of volatile limonene or α-bisabolene that would otherwise be lost to evaporation, and/or that continuous product removal in dodecane alleviates product feedback inhibition to promote higher rates of synthesis. We also investigate limonene and bisabolene production in the ΔglgC genetic background, where carbon partitioning is redirected at the expense of glycogen biosynthesis. The Synechococcus sp. PCC 7002 ΔglgC mutant excreted a suite of overflow metabolites (α-ketoisocaproate, pyruvate, α-ketoglutarate, succinate, and acetate) during nitrogen-deprivation, and also at the onset of stationary growth in nutrient-replete media. None of the excreted metabolites, however, appeared to be effectively utilized for terpenoid metabolism. Interestingly, we observed a 1.6- to 2.5-fold increase in the extracellular concentration of most excreted organic acids when the ΔglgC mutant was conferred with the ability to produce limonene. Overall, Synechococcus sp. PCC 7002 provides a highly promising platform for terpenoid biosynthetic and metabolic engineering efforts.

The effect of gas-phase polycyclic aromatic hydrocarbons on the formation and properties of biogenic secondary organic aerosol particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zelenyuk, Alla; Imre, Dan G.; Wilson, Jacqueline

2017-01-01

When secondary organic aerosol (SOA) particles are formed by ozonolysis in the presence of gas-phase polycyclic aromatic hydrocarbons (PAHs), their formation and properties are significantly different from SOA particles formed without PAHs. For all SOA precursors and all PAHs, discussed in this study, the presence of the gas-phase PAHs during SOA formation significantly affects particle mass loadings, composition, growth, evaporation kinetics, and viscosity. SOA particles formed in the presence of PAHs have, as part of their compositions, trapped unreacted PAHs and products of heterogeneous reactions between PAHs and ozone. Compared to ‘pure’ SOA particles, these particles exhibit slower evaporation kinetics,more » have higher fractions of non-volatile components, like oligomers, and higher viscosities, assuring their longer atmospheric lifetimes. In turn, the increased viscosity and decreased volatility provide a shield that protects PAHs from chemical degradation and evaporation, allowing for the long-range transport of these toxic pollutants. The magnitude of the effect of PAHs on SOA formation is surprisingly large. The presence of PAHs during SOA formation increases mass loadings by factors of two to five, and particle number concentrations, in some cases, by more than a factor of 100. Increases in SOA mass, particle number concentrations, and lifetime have important implications to many atmospheric processes related to climate, weather, visibility, and human health, all of which relate to the interactions between biogenic SOA and anthropogenic PAHs. The synergistic relationship between SOA and PAHs presented here are clearly complex and call for future research to elucidate further the underlying processes and their exact atmospheric implications.« less

User’s guide to the collection and analysis of tree cores to assess the distribution of subsurface volatile organic compounds

USGS Publications Warehouse

Vroblesky, Don A.

2008-01-01

Analysis of the volatile organic compound content of tree cores is an inexpensive, rapid, simple approach to examining the distribution of subsurface volatile organic compound contaminants. The method has been shown to detect several volatile petroleum hydrocarbons and chlorinated aliphatic compounds associated with vapor intrusion and ground-water contamination. Tree cores, which are approximately 3 inches long, are obtained by using an increment borer. The cores are placed in vials and sealed. After a period of equilibration, the cores can be analyzed by headspace analysis gas chromatography. Because the roots are exposed to volatile organic compound contamination in the unsaturated zone or shallow ground water, the volatile organic compound concentrations in the tree cores are an indication of the presence of subsurface volatile organic compound contamination. Thus, tree coring can be used to detect and map subsurface volatile organic compound contamination. For comparison of tree-core data at a particular site, it is important to maintain consistent methods for all aspects of tree-core collection, handling, and analysis. Factors affecting the volatile organic compound concentrations in tree cores include the type of volatile organic compound, the tree species, the rooting depth, ground-water chemistry, the depth to the contaminated horizon, concentration differences around the trunk related to variations in the distribution of subsurface volatile organic compounds, concentration differences with depth of coring related to volatilization loss through the bark and possibly other unknown factors, dilution by rain, seasonal influences, sorption, vapor-exchange rates, and within-tree volatile organic compound degradation.

The potential of epiphytic hydrocarbon-utilizing bacteria on legume leaves for attenuation of atmospheric hydrocarbon pollutants.

PubMed

Ali, Nida; Sorkhoh, Naser; Salamah, Samar; Eliyas, Mohamed; Radwan, Samir

2012-01-01

The leaves of two legumes, peas and beans, harbored on their surfaces up to 9×10⁷ cells g⁻¹ of oil-utilizing bacteria. Less numbers, up to 5×10⁵ cells g⁻¹ inhabited leaves of two nonlegume crops, namely tomato and sunflower. Older leaves accommodated more of such bacteria than younger ones. Plants raised in oily environments were colonized by much more oil-utilizing bacteria than those raised in pristine (oil-free) environments. Similar numbers were counted on the same media in which nitrogen salt was deleted, indicating that most phyllospheric bacteria were probably diazotrophic. Most dominant were Microbacterium spp. followed by Rhodococcus spp., Citrobacter freundii, in addition to several other minor species. The pure bacterial isolates could utilize leaf tissue hydrocarbons, and consume considerable proportions of crude oil, phenanthrene (an aromatic hydrocarbon) and n-octadecane (an alkane) in batch cultures. Bacterial consortia on fresh (but not on previously autoclaved) leaves of peas and beans could also consume substantial proportions of the surrounding volatile oil hydrocarbons in closed microcosms. It was concluded that phytoremediation through phyllosphere technology could be useful in remediating atmospheric hydrocarbon pollutants. Copyright © 2011 Elsevier Ltd. All rights reserved.

EMERGING TECHNOLOGY SUMMARY: PILOT-SCALE DEMONSTRATION OF A TWO-STAGE METHANOTROPHIC BIOREACTOR FOR BIODEGRADATION OF TRICHLOROETHENE IN GROUNDWATER

EPA Science Inventory

BioTrol, Inc., developed a two-stage, methanotrophic, bioreactor system for remediation of water contaminated with trichloroethylene (TCE) and other chlorinated, volatile, aliphatic hydrocarbons. The first stage was a suspended-growth culture vessel with a bubbleless methane tran...

OBSERVATIONS OF NONMETHANE HYDROCARBONS AND OXYGENATED VOLATILE ORGANIC COMPOUNDS AT A RURAL SITE IN THE SOUTHEASTERN UNITED STATES. (R825261)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

4-Nitrophenol, 1-nitropyrene, and 9-nitroanthracene emissions in exhaust particles from diesel vehicles with different exhaust gas treatments

NASA Astrophysics Data System (ADS)

Inomata, Satoshi; Fushimi, Akihiro; Sato, Kei; Fujitani, Yuji; Yamada, Hiroyuki

2015-06-01

The dependence of nitro-organic compound emissions in automotive exhaust particles on the type of aftertreatment used was investigated. Three diesel vehicles with different aftertreatment systems (an oxidation catalyst, vehicle-DOC; a particulate matter and NOx reduction system, vehicle-DPNR; and a urea-based selective catalytic reduction system, vehicle-SCR) and a gasoline car with a three-way catalyst were tested. Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) and nitrophenols in the particles emitted were analyzed by thermal desorption gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. The secondary production of nitro-organic compounds on the filters used to collect particles and the adsorption of gaseous nitro-organic compounds by the filters were evaluated. Emissions of 1-nitropyrene, 9-nitroanthracene, and 4-nitrophenol in the diesel exhaust particles were then quantified. The NOx reduction process in vehicle-DPNR appeared to remove nitro-hydrocarbons efficiently but not to remove nitro-oxygenated hydrocarbons efficiently. The nitro-PAH emission factors were lower for vehicle-DOC when it was not fitted with a catalyst than when it was fitted with a catalyst. The 4-nitrophenol emission factors were also lower for vehicle-DOC with a catalyst than vehicle-DOC without a catalyst, suggesting that the oxidation catalyst was a source of both nitro-PAHs and 4-nitrophenol. The time-resolved aerosol mass spectrometry data suggested that nitro-organic compounds are mainly produced when an engine is working under load. The presence of 4-nitrophenol in the particles was not confirmed statistically because of interference from gaseous 4-nitrophenol. Systematic errors in the estimated amounts of gaseous 1-nitropyrene and 9-nitroanthracene adsorbed onto the filters and the estimated amounts of volatile nitro-organic compounds that evaporated during sampling and during post-sampling conditioning could not be excluded. An analytical method in which all gaseous compounds are absorbed before particles are collected, and in which the volatile compounds are derivatized, would improve the precision and the accuracy of the data.

Detection of radiation-induced hydrocarbons in baked sponged cake prepared with irradiated liquid egg

NASA Astrophysics Data System (ADS)

Schulzki, G.; Spiegelberg, A.; Bögl, K. W.; Schreiber, G. A.

1995-02-01

For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of this fast and efficient technique is demonstrated by the example of detection of radiation-induced HC in fat isolated from baked sponge cake which had been prepared with irradiated liquid egg.

Renewable hydrocarbons for jet fuels from biomass and plastics via microwave-induced pyrolysis and hydrogenation processes

NASA Astrophysics Data System (ADS)

Zhang, Xuesong

This dissertation aims to enhance the production of aromatic hydrocarbons in the catalytic microwave-induced pyrolysis, and maximize the production of renewable cycloalkanes for jet fuels in the hydrogenation process. In the process, ZSM-5 catalyst as the highly efficient catalyst was employed for catalyzing the pyrolytic volatiles from thermal decomposition of cellulose (a model compound of lignocellulosic biomass). A central composite experiment design (CCD) was used to optimize the product yields as a function of independent factors (e.g. catalytic temperature and catalyst to feed mass ratio). The low-density polyethylene (a mode compound of waste plastics) was then carried out in the catalytic microwave-induced pyrolysis in the presence of ZSM-5 catalyst. Thereafter, the catalytic microwave-induced co-pyrolysis of cellulose with low-density polyethylene (LDPE) was conducted over ZSM-5 catalyst. The results showed that the production of aromatic hydrocarbons was significantly enhanced and the coke formation was also considerably reduced comparing with the catalytic microwave pyrolysis of cellulose or LDPE alone. Moreover, practical lignocellulosic biomass (Douglas fir sawdust pellets) was converted into aromatics-enriched bio-oil by catalytic microwave pyrolysis. The bio-oil was subsequently hydrogenated by using the Raney Ni catalyst. A liquid-liquid extraction step was implemented to recover the liquid organics and remove the water content. Over 20% carbon yield of liquid product regarding lignocellulosic biomass was obtained. Up to 90% selectivity in the liquid product belongs to jet fuel range cycloalkanes. As the integrated processes was developed, catalytic microwave pyrolysis of cellulose with LDPE was conducted to improve aromatic production. After the liquid-liquid extraction by the optimal solvent (n-heptane), over 40% carbon yield of hydrogenated organics based on cellulose and LDPE were achieved in the hydrogenation process. As such, real lignocellulosic biomass with LDPE were transformed into aromatics via co-feed catalytic microwave pyrolysis. It was also found that close to 40% carbon yield of hydrogenated organics were garnered. Based on these outcomes, the reaction kinetics regarding non-catalytic co-pyrolysis and catalytic co-pyrolysis of biomass with plastics were also presented. In addition, the techno-economic analysis of the catalytically integrated processes from lignocellulosic biomass to renewable cycloalkanes for jet fuels was evaluated in the dissertation as well.

Hydrocarbon productivities in different Botryococcus strains: comparative methods in product quantification.

PubMed

Eroglu, Ela; Okada, Shigeru; Melis, Anastasios

2011-08-01

Six different strains of the green microalgae Botryococcus belonging to the A-race or B-race, accumulating alkadiene or botryococcene hydrocarbons, respectively, were compared for biomass and hydrocarbon productivities. Biomass productivity was assessed gravimetrically upon strain growth in the laboratory under defined conditions. Hydrocarbon productivities were measured by three different and independent experimental approaches, including density equilibrium of the intact cells and micro-colonies, spectrophotometric analysis of hydrocarbon extracts, and gravimetric quantitation of eluted hydrocarbons. All three hydrocarbon-quantitation methods yielded similar results for each of the strains examined. The B-race microalgae Botryococcus braunii var. Showa and Kawaguchi-1 constitutively accumulated botryococcene hydrocarbons equivalent to 30% and 20%, respectively, of their overall biomass. The A-race microalgae Botryococcus braunii, varieties Yamanaka, UTEX 2441 and UTEX LB572 constitutively accumulated alkadiene hydrocarbons ranging from 14% to 13% and 10% of their overall biomass, respectively. Botryococcus sudeticus (UTEX 2629), a morphologically different green microalga, had the lowest hydrocarbon accumulation, equal to about 3% of its overall biomass. Results validate the density equilibrium and spectrophotometric analysis methods in the quantitation of botryococcene-type hydrocarbons. These analytical advances will serve in the screening and selection of B. braunii and of other microalgae in efforts to identify those having a high hydrocarbon content for use in commercial applications.

Polycyclic Aromatic Hydrocarbon Sources and Trapping within Secondary Organic Aerosol

NASA Astrophysics Data System (ADS)

Wallace, H. W., IV; Sanchez, N. P.; Flynn, J. H., III; Lefer, B. L.; Bottenus, C. L. H.; VanReken, T. M.; Griffin, R. J.

2017-12-01

As part of the BEETEX field study, which occurred from Feburary 7 to 27, 2015, a mobile air quality laboratory was stationed near a major refinery proximate to the Houston Ship Channel to characterize the chemical nature and sources of atmospheric particulate matter (PM) using a high-resolution time-of-flight mass spectrometer. Positive matrix factorization (PMF) was performed on the organic signal of the aerosol mass spectra, resulting in five factors totaling an average of 4.1 μg/m3 of organic aerosol: hydrocarbon-like (0.67 μg/m3), cooking (0.35 μg/m3), biomass burning (1.14 μg/m3), low-volatility oxidized (1.15 μg/m3), and semi-volatile oxidized (0.78 μg/m3). As part of this study, two techniques to quantify particulate polycyclic aromatic hydrocarbons (PAHs) were compared: one capable of quantifying non-refractory molecular ion PAHs and the other sensitive only to surface bound PAHs. Together with PMF model results on the non-refractory organic PM data, we show that particulate PAHs likely are trapped inside secondary organic aerosol (SOA) as it deposits onto particles and that the two major sources of PAHs in the area are from biomass burning and use of internal combustion engines. Because this SOA may prevent particle-phase consumption of the PAH material, these results have important implications for long-range transport of particulate PAHs.

Microscale Variations in the 13C Content of the Murchison Meteorite

NASA Astrophysics Data System (ADS)

Romanek, C.; Gibson, E.; Socki, R.; Burkett, P. J.

1993-07-01

Heretofore unresolved micrometer-scale carbon isotopic zonation in the Murchison meteorite (CM3) is documented using a laser microprobe mass spectrometer. High-resolution isotopic gradients and heterogeneities between high- and low-temperature textural components help to constrain the processes that have shaped the physiochemical character of this carbonaceous chondrite. Previous bulk samples of Murchison yield an average delta ^13C value of - 5.7 +/- 4.3 per mil [1] while individual components such as micrometer-sized mineral separates (e.g., C(sub)graphite , C(sub)diamond, and SiC), acid- soluble extracts (e.g., CaCO3 and polar hydrocarbons), and insoluble residues (e.g., polycyclic aromatic hydrocarbons) are isotopically diverse (delta ^13C of -1000 to 29,000 per mil). While these studies shed light on the origin and occurrence of C-bearing phases, they fail to constrain intrinsic spatial isotopic heterogeneities. The power of the laser microprobe lies in the fact that in situ chemical and isotopic compositions are measured simultaneously for volatiles extracted from extremely small sample volumes (i.e., 0.025 mm^3 for 5 wt% C). Nd-YAG laser irradiation (1.06 micrometers) is directed onto texturally defined targets (>=50 micrometers wide) from which solid material is volatilized. Condensible gaseous phases are collected in a variable-temperature cold trap while the more volatile species (CH4 and CO) are quantified using an ion trap mass spectrometer. All gases are then converted to CO2 in a CuO furnace (containing Pt) held at 600 degrees C and analyzed for carbon and oxygen isotope ratios. The concentration and isotopic composition of condensed species are determined by stepped sublimation of unstable components and conversion to CO2. Preliminary isotopic analyses of the total volatile C content (i.e., bulk microanalysis) from distinct textural components at least 0.05 mm^3 in volume are described below. The most ^13C-depleted components within Murchison reside within the cores of chondrules and/or aggregates. Three typical cores were analyzed, with an average bulk composition of -21.0 +/- 0.5 per mil (n = 7). The bulk ^13C content of C-bearing phases increases monotonically outward in all directions within 100 to 200 micrometers of each core (i.e., within dust mantles) to a constant matrix value of -12.5 +/- 0.5 per mil (n = 40). The most isotopically enriched textural component found in Murchison is a regolith breccia clast without chondrules that has an average bulk delta ^13C value of -10 +/-0.5 per mil (n = 5). The clast was originally detectable only under cathodoluminescence, but with the aid of the laser microprobe it is now characterized by an unusually low volatile content and enriched ^13C composition. In general, the most isotopically enriched components also produce the lowest yield of gas (normalized to sampling volume). This trend of isotopic enrichment from chondrule to matrix has been documented previously for oxygen isotopes in carbonaceous chondrites [2]. Carbon isotopic gradients and heterogeneities within Murchison reflect fundamental changes in the chemical speciation and/or isotopic content of the main C-bearing components (i.e., acid-soluble and insoluble hydrocarbon fractions) within the meteorite. Perhaps core interiors and dust mantles are responding to environmental changes reflected in the speciation of C-bearing species distributed within the solar nebula or the parent body. Inverse correlations between hydrocarbon atomic mass number and ^13C abundance in the acid-soluble [3] and insoluble residues [4] of Murchison have been documented. Alternatively, micrometer-scale isotopic gradients may reflect fundamental changes in the isotopic composition of individual C-bearing species through time. Enrichments may represent kinetically controlled processes related to hydrocarbon formation. In contrast, assuming an equilibrium fractionation mechanism, isotopic enrichments may record a temperature-dependent component to hydrocarbon delta ^13C values. These opposing alternatives will be discussed in light of the isotopic composition of individual C-bearing components volatilized from tightly constrained sample volumes within Murchison. References: [1] Kerridge J. F. (1985) GCA, 49, 1707-1714. [2] Clayton R. N. and Mayeda T. K. (1984) EPSL, 67, 151-161. [3] Yuen G. et al. (1984) Nature, 307, 254. [4] Gilmour I. et al. (1991) Meteoritics, 26, 337-338.

Bioremediation of poly-aromatic hydrocarbon (PAH)-contaminated soil by composting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loick, N.; Hobbs, P.J.; Hale, M.D.C.

2009-07-01

This paper presents a comprehensive and critical review of research on different co-composting approaches to bioremediate hydrocarbon contaminated soil, organisms that have been found to degrade PAHs, and PAH breakdown products. Advantages and limitations of using certain groups of organisms and recommended areas of further research effort are identified. Studies investigating the use of composting techniques to treat contaminated soil are broad ranging and differ in many respects, which makes comparison of the different approaches very difficult. Many studies have investigated the use of specific bio-additives in the form of bacteria or fungi with the aim of accelerating contaminant removal;more » however, few have employed microbial consortia containing organisms from both kingdoms despite knowledge suggesting synergistic relationships exist between them in contaminant removal. Recommendations suggest that further studies should attempt to systemize the investigations of composting approaches to bio-remediate PAH-contaminated soil, to focus on harnessing the biodegradative capacity of both bacteria and fungi to create a cooperative environment for PAH degradation, and to further investigate the array of PAHs that can be lost during the composting process by either leaching or volatilization.« less

Characterization of VOCs Across Pennsylvania: Assessing Emissions from Rural, Forested, Agricultural and Natural Gas Drilling-Impacted Areas

NASA Astrophysics Data System (ADS)

Grannas, A. M.; Fuentes, J. D.; Ramos-Garcés, F.; Wang, D. K.; Martins, D. K.

2012-12-01

Volatile organic compounds (VOCs) of both biogenic and anthropogenic origin are important to troposphere chemistry, particularly the formation of photochemical smog and secondary organic aerosol. There is concern that increased natural gas exploration may lead to increased emissions of certain VOCs during well development and due to fugitive emissions from operational well sites and pipelines. For a six-day period in June 2012, a variety of VOCs were measured using canister sampling from a mobile measurement platform. Transects from southwestern to northeastern Pennsylvania were studied, with samples obtained in rural, forested, urban, farm-impacted and gas well-impacted sites. As expected, biogenic VOCs and isoprene oxidation products were enhanced in forested regions, while anthropogenic non-methane hydrocarbons were enhanced in urban areas. BTEX (benzene, toluene, ethylbenzene and xylenes) was enhanced in urban areas, but the concentrations of BTEX measured near developing and existing natural gas sites were similar to rural and forested sites. Halogenated hydrocarbons and Freon compounds were consistent at all site locations. We will discuss the specific concentrations and signatures of these compounds and assess the potential impact of agricultural activities and gas well development on the observed VOC concentrations and variability.

Flavor characterization of sugar-added pennywort (Centella asiatica L.) juices treated with ultra-high pressure and thermal processes.

PubMed

Apichartsrangkoon, Arunee; Wongfhun, Pronprapa; Gordon, Michael H

2009-01-01

The flavor characteristics of pennywort juices with added sugar treated by ultra-high pressure, pasteurization, and sterilization were investigated using solid phase microextraction combined with gas chromatography-mass spectrometry. It was found that sesquiterpene hydrocarbons comprised the major class of volatile components present and the juices had a characteristic aroma due to the presence of volatiles including beta-caryophyllene and humulene and alpha-copaene. In comparison with heated juices, HPP-treated samples could retain more volatile compounds such as linalool and geraniol similar to those present in fresh juice, whereas some volatiles such as alpha-terpinene and ketone class were apparently formed by thermal treatment. All processing operations produced juice that was not significantly different in the concentration of total volatiles. Practical Application: Pennywort juice is considered a nutraceutical drink for health benefits. Therefore, to preserve all aroma and active components in this juice, a nonthermal process such as ultra-high pressure should be a more appropriate technique for retention of its nutritive values than pasteurization and sterilization.

The Puzzle of HCN in Comets: Is it both a Product and a Primary Species?

NASA Astrophysics Data System (ADS)

Mumma, Michael J.; Bonev, Boncho P.; Charnley, Steven B.; Cordiner, Martin A.; DiSanti, Michael A.; Gibb, Erika L.; Magee-Sauer, Karen; Paganini, Lucas; Villanueva, Geronimo L.

2014-11-01

Hydrogen cyanide has long been regarded as a primary volatile in comets, stemming from its presence in dense molecular cloud cores and its supposed storage in the cometary nucleus. Here, we examine the observational evidence for and against that hypothesis, and argue that HCN may also result from near-nucleus chemical reactions in the coma. The distinction (product vs. primary species) is important for multiple reasons: 1. HCN is often used as a proxy for water when the dominant species (H2O) is not available for simultaneous measurement, as at radio wavelengths. 2. HCN is one of the few volatile carriers of nitrogen accessible to remote sensing. If HCN is mainly a product species, its precursor becomes the more important metric for compiling a taxonomic classification based on nitrogen chemistry. 3. The stereoisomer HNC is now confirmed as a product species. Could reaction of a primary precursor (X-CN) with a hydrocarbon co-produce both HNC and HCN? 4. The production rate for CN greatly exceeds that of HCN in some comets, demonstrating the presence of another (more important) precursor of CN. Several puzzling lines of evidence raise issues about the origin of HCN: a. The production rates of HCN measured through rotational (radio) and vibrational (infrared) spectroscopy agree in some comets - in others the infrared rate exceeds the radio rate substantially. b. With its strong dipole moment and H-bonding character, HCN should be linked more strongly in the nuclear ice to other molecules with similar properties (H2O, CH3OH), but instead its spatial release in some comets seems strongly coupled to volatiles that lack a dipole moment and thus do not form H-bonds (methane, ethane). c. The nucleus-centered rotational temperatures measured for H2O and other species (C2H6, CH3OH) usually agree within error, but those for HCN are often slightly smaller. d. In comet ISON, ALMA maps of HCN and the dust continuum show a slight displacement 80 km) in the centroids. We will discuss these points, and suggest ways to test the primary and product origins of cometary HCN. NASA’s Planetary Astronomy, Planetary Atmospheres, and Astrobiology Programs supported this work.

Biofiltration of gasoline and diesel aliphatic hydrocarbons.

PubMed

Halecky, Martin; Rousova, Jana; Paca, Jan; Kozliak, Evguenii; Seames, Wayne; Jones, Kim

2015-02-01

The ability of a biofilm to switch between the mixtures of mostly aromatic and aliphatic hydrocarbons was investigated to assess biofiltration efficiency and potential substrate interactions. A switch from gasoline, which consisted of both aliphatic and aromatic hydrocarbons, to a mixture of volatile diesel n-alkanes resulted in a significant increase in biofiltration efficiency, despite the lack of readily biodegradable aromatic hydrocarbons in the diesel mixture. This improved biofilter performance was shown to be the result of the presence of larger size (C₉-C(12)) linear alkanes in diesel, which turned out to be more degradable than their shorter-chain (C₆-C₈) homologues in gasoline. The evidence obtained from both biofiltration-based and independent microbiological tests indicated that the rate was limited by biochemical reactions, with the inhibition of shorter chain alkane biodegradation by their larger size homologues as corroborated by a significant substrate specialization along the biofilter bed. These observations were explained by the lack of specific enzymes designed for the oxidation of short-chain alkanes as opposed to their longer carbon chain homologues.

Degradation of polycyclic aromatic hydrocarbons (PAHs) present in used motor oil and implications for urban runoff quality

NASA Astrophysics Data System (ADS)

Ferreira, M.; Stenstrom, M. K.; Lau, S.

2013-12-01

Polycyclic aromatic hydrocarbons (PAHs) are common organic pollutants of urban stormwater runoff due to atmospheric deposition, vehicle-related discharges, and coal tar pavement sealants. The US EPA lists sixteen PAHs as priority pollutants and seven of those are potential carcinogenic compounds. Due to their molecular structure, PAHs tend to attach to particles that will subsequently be deposited as sediments in waterways. This study focuses on the degradation of PAHs present in used motor oil. Four experimental setups were used to simulate volatilization and photooxidation in the degradation of sixteen PAHs as observed for up to 54 days. The volatilization-only experiment showed substantial reduction only in the concentration of Napthalene (Nap). However, photooxidation-only was more efficient in degrading PAHs. In this process, substantial reduction in the concentrations of Nap, Acenapthene (Anthe), Anthracene (ANT), Fluoranthene (FLT), Pyrene (PYR), Benz[a]anthracene (BaA), Benzo[a]pyrene (BaP), Indeno[1,2,3,cd]pyrene (INP), and Benz[g,h,i]perylene (BghiP) were observed as early as five days. The two volatilization-photooxidation experiments exhibited substantial reduction in the concentrations of Fluorene (FLU), Chrysene (CHR) and Benzo[b]fluoranthene (BbF), in addition to the PAHs reduced by photooxidation-only. Phenanthrene (PHE), Fluoranthene (FLT), and Benzo[b]fluoranthene (BbF) only exhibited substantial decreased concentrations after 20 days in the volatilization-photooxidation experiment. One PAH, acenapthylene (Anthy), was not detected in the original sample of used motor oil. The highest degradations were observed in the combined volatilization-photooxidation experiment. In regions with infrequent rainfall, such as Southern California, molecules of PAHs attached to highway particles will have time to undergo degradation prior to transport. Therefore, PAHs may be present in lower concentrations in highway runoff in dry climates than in rainy climates. To support this hypothesis, a review of highway-related PAHs concentrations is presented.

The formation of Charon's red poles from seasonally cold-trapped volatiles

NASA Astrophysics Data System (ADS)

Grundy, W. M.; Cruikshank, D. P.; Gladstone, G. R.; Howett, C. J. A.; Lauer, T. R.; Spencer, J. R.; Summers, M. E.; Buie, M. W.; Earle, A. M.; Ennico, K.; Parker, J. Wm.; Porter, S. B.; Singer, K. N.; Stern, S. A.; Verbiscer, A. J.; Beyer, R. A.; Binzel, R. P.; Buratti, B. J.; Cook, J. C.; Dalle Ore, C. M.; Olin, C. B.; Parker, A. H.; Protopapa, S.; Quirico, E.; Retherford, K. D.; Robbins, S. J.; Schmitt, B.; Stansberry, J. A.; Umurhan, O. M.; Weaver, H. A.; Young, L. A.; Zangari, A. M.; Bray, V. J.; Cheng, A. F.; McKinnon, W. B.; McNutt, R. L.; Morre, J. M.; Nimmo, F.; Reuter, D. C.; Schenk, P. M.; New Horizons Science Team; Stern, S. A.; Bagenal, F.; Ennico, K.; Gladstone, G. R.; Grundy, W. M.; McKinnon, W. B.; Moore, J. M.; Olkin, C. B.; Spencer, J. R.; Weaver, H. A.; Young, L. A.; Andert, T.; Barnouin, O.; Beyer, R. A.; Binzel, R. P.; Bird, M.; Bray, V. J.; Brozovic, M.; Buie, M. W.; Buratti, B. J.; Cheng, A. F.; Cook, J. C.; Cruikshank, D. P.; Dalle Ore, C. M.; Earler, A. M.; Elliott, H. A.; Greathouse, T. K.; Hahn, M.; Hamilton, D. P.; Hill, M. E.; Hinson, D. P.; Hofgartner, J.; Horányi, M.; Howard, A. D.; Howett, C. J. A.; Jennings, D. E.; Kammer, J. A.; Kollmann, P.; Lauer, T. R.; Lavvas, P.; Linscott, I. R. Lisse, C. M.; Lunsford, A. W.; McComas, D. J.; McNutt, R. L., Jr.; Mutchler, M.; Nimmo, F.; Nunez, J. I.; Paetzold, M.; Parker, A. H.; Parker, J. Wm.; Philippe, S.; Piquette, M.; Porter, S. B.; Protopapa, S.; Quirico, E.; Reitsema, H. J.; Reuter, D. C.; Robbins, S. J.; Roberts, J. H.; Runyon, K.; Schenk, P. M.; Schindhelm, E.; Schmitt, B.; Showalter, M. R.; Singer, K. N.; Stansberry, J. A.; Steffl, A. J.; Strobel, D. F.; Stryk, T.; Summers, M. E.; Szalay, J. R.; Throop, H. B.; Tsang, C. C. C.; Tyler, G. L.; Umurhan, O. M.; Verbiscer, A. J.; Versteeg, M. H.; Weigle, G. E., II; White, O. L.; Woods, W. W.; Young, E. F.; Zangari, A. M.

2016-11-01

A unique feature of Pluto's large satellite Charon is its dark red northern polar cap. Similar colours on Pluto's surface have been attributed to tholin-like organic macromolecules produced by energetic radiation processing of hydrocarbons. The polar location on Charon implicates the temperature extremes that result from Charon's high obliquity and long seasons in the production of this material. The escape of Pluto's atmosphere provides a potential feedstock for a complex chemistry. Gas from Pluto that is transiently cold-trapped and processed at Charon's winter pole was proposed as an explanation for the dark coloration on the basis of an image of Charon's northern hemisphere, but not modelled quantitatively. Here we report images of the southern hemisphere illuminated by Pluto-shine and also images taken during the approach phase that show the northern polar cap over a range of longitudes. We model the surface thermal environment on Charon and the supply and temporary cold-trapping of material escaping from Pluto, as well as the photolytic processing of this material into more complex and less volatile molecules while cold-trapped. The model results are consistent with the proposed mechanism for producing the observed colour pattern on Charon.

The Formation of Charon's Red Poles from Seasonally Cold-Trapped Volatiles

NASA Technical Reports Server (NTRS)

Grundy, W. M.; Cruikshank, D. P.; Gladstone, D. R.; Howett, C. J. A.; Lauer, T. R.; Spencer, J. R.; Summers, M. E.; Buie, M. W.; Earle, A. M.; Ennico, K.;

The formation of Charon's red poles from seasonally cold-trapped volatiles.

PubMed

Grundy, W M; Cruikshank, D P; Gladstone, G R; Howett, C J A; Lauer, T R; Spencer, J R; Summers, M E; Buie, M W; Earle, A M; Ennico, K; Parker, J Wm; Porter, S B; Singer, K N; Stern, S A; Verbiscer, A J; Beyer, R A; Binzel, R P; Buratti, B J; Cook, J C; Dalle Ore, C M; Olkin, C B; Parker, A H; Protopapa, S; Quirico, E; Retherford, K D; Robbins, S J; Schmitt, B; Stansberry, J A; Umurhan, O M; Weaver, H A; Young, L A; Zangari, A M; Bray, V J; Cheng, A F; McKinnon, W B; McNutt, R L; Moore, J M; Nimmo, F; Reuter, D C; Schenk, P M

2016-11-03

A unique feature of Pluto's large satellite Charon is its dark red northern polar cap. Similar colours on Pluto's surface have been attributed to tholin-like organic macromolecules produced by energetic radiation processing of hydrocarbons. The polar location on Charon implicates the temperature extremes that result from Charon's high obliquity and long seasons in the production of this material. The escape of Pluto's atmosphere provides a potential feedstock for a complex chemistry. Gas from Pluto that is transiently cold-trapped and processed at Charon's winter pole was proposed as an explanation for the dark coloration on the basis of an image of Charon's northern hemisphere, but not modelled quantitatively. Here we report images of the southern hemisphere illuminated by Pluto-shine and also images taken during the approach phase that show the northern polar cap over a range of longitudes. We model the surface thermal environment on Charon and the supply and temporary cold-trapping of material escaping from Pluto, as well as the photolytic processing of this material into more complex and less volatile molecules while cold-trapped. The model results are consistent with the proposed mechanism for producing the observed colour pattern on Charon.

A Combined Kinetic and Volatility Basis Set Approach to Model Secondary Organic Aerosol from Toluene and Diesel Exhaust/Meat Cooking Mixtures

NASA Astrophysics Data System (ADS)

Parikh, H. M.; Carlton, A. G.; Zhang, H.; Kamens, R.; Vizuete, W.

2011-12-01

Secondary organic aerosol (SOA) is simulated for 6 outdoor smog chamber experiments using a SOA model based on a kinetic chemical mechanism in conjunction with a volatility basis set (VBS) approach. The experiments include toluene, a non-SOA-forming hydrocarbon mixture, diesel exhaust or meat cooking emissions and NOx, and are performed under varying conditions of relative humidity. SOA formation from toluene is modeled using a condensed kinetic aromatic mechanism that includes partitioning of lumped semi-volatile products in particle organic-phase and incorporates particle aqueous-phase chemistry to describe uptake of glyoxal and methylglyoxal. Modeling using the kinetic mechanism alone, along with primary organic aerosol (POA) from diesel exhaust (DE) /meat cooking (MC) fails to simulate the rapid SOA formation at the beginning hours of the experiments. Inclusion of a VBS approach with the kinetic mechanism to characterize the emissions and chemistry of complex mixture of intermediate volatility organic compounds (IVOCs) from DE/MC, substantially improves SOA predictions when compared with observed data. The VBS model includes photochemical aging of IVOCs and evaporation of POA after dilution. The relative contribution of SOA mass from DE/MC is as high as 95% in the morning, but substantially decreases after mid-afternoon. For high humidity experiments, aqueous-phase SOA fraction dominates the total SOA mass at the end of the day (approximately 50%). In summary, the combined kinetic and VBS approach provides a new and improved framework to semi-explicitly model SOA from VOC precursors in conjunction with a VBS approach that can be used on complex emission mixtures comprised with hundreds of individual chemical species.

Effect of proteolysis index level on instrumental adhesiveness, free amino acids content and volatile compounds profile of dry-cured ham.

PubMed

Pérez-Santaescolástica, C; Carballo, J; Fulladosa, E; Garcia-Perez, José V; Benedito, J; Lorenzo, J M

2018-05-01

Defective textures in dry-cured ham are a common problem that causes important economic losses in the ham industry. An increase of proteolysis during the dry-cured ham processing may lead to high adhesiveness and consumer rejection of the product. Therefore, the influence of proteolysis index (PI) on instrumental adhesiveness, free amino acids and volatile profile of dry-cured ham was assessed. Two hundred Spanish dry-cured ham units were firstly classified according to their PI: low PI (<32%), medium PI (32-36%) and high PI (>36%). Instrumental adhesiveness was affected by PI, showing the lowest values in the batch with low PI. Significant differences (P < 0.05) among groups were found in six amino acids: serine, taurine, cysteine, methionine, isoleucine and leucine. The content of leucine, serine, methionine, and isoleucine significantly (P < 0.05) increased as the proteolysis index rose. However, taurine and cysteine content showed an opposite behaviour, reaching the highest values in the dry-cured hams with low PI. Significant differences (P < 0.001) in the total content of volatile compounds among ham groups were observed, with the highest concentration in the batch with low PI, and decreasing the concentration as the PI increased. Regarding the different chemical families of volatiles, the hydrocarbons (the main family), alcohols, aldehydes, ketones and acids were more abundant in the hams showing the lowest PI. Esters did not show significant differences among the three batches of hams studied. The present study demonstrated that, apart from the effect on the adhesiveness, an excessive proteolysis seems to be associated with negative effects on the taste and aroma of the dry-cured ham. Copyright © 2018 Elsevier Ltd. All rights reserved.

Exploring the Saccharomyces cerevisiae Volatile Metabolome: Indigenous versus Commercial Strains

PubMed Central

Alves, Zélia; Melo, André; Figueiredo, Ana Raquel; Coimbra, Manuel A.; Gomes, Ana C.; Rocha, Sílvia M.

2015-01-01

Winemaking is a highly industrialized process and a number of commercial Saccharomyces cerevisiae strains are used around the world, neglecting the diversity of native yeast strains that are responsible for the production of wines peculiar flavours. The aim of this study was to in-depth establish the S. cerevisiae volatile metabolome and to assess inter-strains variability. To fulfill this objective, two indigenous strains (BT2652 and BT2453 isolated from spontaneous fermentation of grapes collected in Bairrada Appellation, Portugal) and two commercial strains (CSc1 and CSc2) S. cerevisiae were analysed using a methodology based on advanced multidimensional gas chromatography (HS-SPME/GC×GC-ToFMS) tandem with multivariate analysis. A total of 257 volatile metabolites were identified, distributed over the chemical families of acetals, acids, alcohols, aldehydes, ketones, terpenic compounds, esters, ethers, furan-type compounds, hydrocarbons, pyrans, pyrazines and S-compounds. Some of these families are related with metabolic pathways of amino acid, carbohydrate and fatty acid metabolism as well as mono and sesquiterpenic biosynthesis. Principal Component Analysis (PCA) was used with a dataset comprising all variables (257 volatile components), and a distinction was observed between commercial and indigenous strains, which suggests inter-strains variability. In a second step, a subset containing esters and terpenic compounds (C10 and C15), metabolites of particular relevance to wine aroma, was also analysed using PCA. The terpenic and ester profiles express the strains variability and their potential contribution to the wine aromas, specially the BT2453, which produced the higher terpenic content. This research contributes to understand the metabolic diversity of indigenous wine microflora versus commercial strains and achieved knowledge that may be further exploited to produce wines with peculiar aroma properties. PMID:26600152

Chemical Composition of the Semi-Volatile Grains of Comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Wurz, P.; Altwegg, K.; Balsiger, H. R.; Berthelier, J. J.; De Keyser, J.; Fiethe, B.; Fuselier, S. A.; Gasc, S.; Gombosi, T. I.; Korth, A.; Mall, U.; Reme, H.; Rubin, M.; Tzou, C. Y.

2017-12-01

Rosetta was in orbit of comet 67P/Churyumov-Gerasimenko from August 2014 to September 2016. On board is the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) experiment that has been continuously collecting data on the chemical composition and activity of the coma from 3.5 AU to pericentre at 1.24 AU and out again to 3.5 AU. ROSINA consists of two mass spectrometers, the Double Focusing Mass Spectrometer (DFMS) and the Reflectron-type Time-Of-Flight (RTOF), as well as the COmet Pressure Sensor (COPS). ROSINA recorded the neutral gas and thermal plasma in the comet's coma. The two mass spectrometers have high dynamic ranges and complement each other with high mass resolution, and high time resolution and large mass range. COPS measures total gas densities, bulk velocities, and gas temperatures. Occasionally, a dust grain of cometary origin enters the ion source of a ROSINA instrument where the volatile part evaporates since these ion sources are hot. The release of volatiles from cometary dust grains was observed with all three ROSINA instruments on several occasions. Because the volatile content of such a dust grain is completely evaporated after a few seconds, the RTOF instrument is best suited for the investigation of its chemical composition since complete mass spectra are recorded during this time. During the mission 9 dust grains were observed with RTOF during the October 2014 to July 2016 time period. It is estimated that these grains contain about 10-15 g of volatiles. The mass spectra were interpreted with a set of 75 molecules, with the major groups of chemical species being hydrocarbons, oxygenated hydrocarbons, nitrogen-bearing molecules, sulphur-bearing molecules, halogenated molecules and others. About 70% of these grains are depleted in water compared to the comet coma, thus, can be considered as semi-volatile dust grains, and the other about 30% are water grains. The chemical composition varies considerably from grain to grain, indicating large chemical heterogeneity at these scales. In contrast, the elemental abundances vary much less.

Sensory aspects of trail-following behaviors in the Asian longhorned beetle, Anoplophora glabripennis

Treesearch

Fern Graves; Thomas C. Baker; Aijun Zhang; Melody Keena; Kelli Hoover

2016-01-01

Anoplophora glabripennis has a complex suite of mate-finding behaviors, the functions of which are not entirely understood. These behaviors are elicited by a number of factors, including visual and chemical cues. Chemical cues include a maleproduced volatile semiochemical acting as a long-range sex pheromone, a femaleproduced cuticular hydrocarbon...

Participant-Based Monitoring of Indoor and Outdoor Nitrogen Dioxide, Volatile Organic Compounds, and Polycyclic Aromatic Hydrocarbons among MICA-Air Households

EPA Science Inventory

The Mechanistic Indicators of Childhood Asthma (MICA) study in Detroit, Michigan introduced a participant-based approach to reduce the resource burden associated with collection of indoor and outdoor residential air sampling data. A subset of participants designated as MICA-Air c...

Aerogel volatiles concentrator and analyzer (AVCA) - Collection and concentration of trace volatile organics in aerogel for spectroscopic detection

NASA Astrophysics Data System (ADS)

Tsapin, A.; Jones, S.; Petkov, M.; Borchardt, D.; Anderson, M.

2017-03-01

A study was conducted to determine the efficacy of using silica aerogel to collect and concentrate ambient trace organics for spectroscopic analysis. Silica aerogel was exposed to atmospheres containing trace amounts of polycyclic aromatic and aliphatic hydrocarbons. The organics present were concentrated in the aerogels by factors varying from 10 to more than 1000 over the levels found in the atmospheres, depending on the specific organic present. Since silica aerogel is transparent over a wide range of optical and near infrared wavelengths, UV-induced fluorescence, Raman and infrared spectroscopies were used to detect and identify the organics collected by the aerogel. Measurements were conducted to determine the sensitivity of these spectroscopic methods for determining organics concentrated by aerogels and the effectiveness of this method for identifying systems containing multiple organic species. Polycyclic aromatic hydrocarbons (PAHs) were added to simulated Mars regolith and then vaporized by modest heating in the presence of aerogel. The aerogels adsorbed and concentrated the PAHs, which were detected by induced fluorescence and Raman and FTIR spectroscopies.

Flavor characteristics of seven grades of black tea produced in Turkey.

PubMed

Alasalvar, Cesarettin; Topal, Bahar; Serpen, Arda; Bahar, Banu; Pelvan, Ebru; Gökmen, Vural

2012-06-27

Seven grades of black tea [high-quality black tea (grades 1-3) and low-quality black tea (grades 4-7)], processed by ÇAYKUR Tea Processing Plant (Rize, Turkey), were compared for their differences in descriptive sensory analysis (DSA), aroma-active compounds (volatile compounds), and taste-active compounds (sugar, organic acid, and free amino acid compositions). Ten flavor attributes such as 'after taste', 'astringency', 'bitter', 'caramel-like', 'floral/sweet', 'green/grassy', 'hay-like', 'malty', 'roasty', and 'seaweed' were identified. Intensities for a number of flavor attributes ('after taste', 'caramel-like', 'malty', and 'seaweed') were not significantly different (p > 0.05) among seven grades of black tea. A total of 57 compounds in seven grades of black tea (14 aldehydes, eight alcohols, eight ketones, two esters, four aromatic hydrocarbons, five aliphatic hydrocarbons, nine terpenes, two pyrazines, one furan, two acids, and two miscellaneous compounds) were tentatively identified. Of these, aldeyhdes comprised more than 50% to the total volatile compounds identified. In general, high-grade quality tea had more volatiles than low-grade quality tea. With respect to taste-active compounds, five sugars, six organic acids, and 18 free amino acids were positively identified in seven grades of black tea, of which fructose, tannic acid, and theanine predominated, respectively. Some variations (p < 0.05), albeit to different extents, were observed among volatile compounds, sugars, organic acids, and free amino acids in seven grades of black tea. The present study suggests that a certain flavor attributes correlate well with taste- and aroma-active compounds. High- and low-quality black teas should not be distinguished solely on the basis of their DSA and taste- and aroma-active compounds. The combination of taste-active compounds together with aroma-active compounds renders combination effects that provide the characteristic flavor of each grade of black tea.

Ground-water contamination at an inactive coal and oil gasification plant site, Gas Works Park, Seattle, Washington

USGS Publications Warehouse

Turney, G.L.; Goerlitz, D.F.

1989-01-01

Gas Works Park, in Seattle, Washington, is located on the site of a coal and oil gasification plant that ceased operation in 1956. During operation, many types of wastes, including coal, tar, and oil, accumulated on site. The park soil is presently (1986) contaminated with compounds such as polynuclear aromatic hydrocarbons, volatile organic compounds, trace metals, and cyanide. Analyses of water samples from a network of observation wells in the park indicate that these compounds are also present in the groundwater. Polynuclear aromatic hydrocarbons and volatile organic compounds were identified in groundwater samples in concentrations as large as 200 mg/L. Concentrations of organic compounds were largest where groundwater was in contact with a nonaqueous phase liquid in the soil. Concentrations in groundwater were much smaller where no nonaqueous phase liquid was present, even if the groundwater was in contact with contaminated soils. This condition is attributed to weathering processes at the site, such as dissolution, volatilization, and biodegradation. Soluble, volatile, low-molecular-weight organic compounds are preferentially dissolved from the nonaqueous phase liquid into the groundwater. Where no nonaqueous phase liquid is present, only stained soils containing relatively insoluble, high-molecular-weight compounds remain; therefore, contaminant concentrations in the groundwater are much smaller. Concentrations of organic contaminants in the soils may still remain large. Values of specific conductance were as large as 5,280 microsiemens/cm, well above a background of 242 microsiemens/cm, suggesting large concentrations of minerals in the groundwater. Trace metal concentrations, however , were generally < 0.010 mg/L, and below limits of US EPA drinking water standards. Cyanide was present in groundwater samples from throughout the park, ranging in concentration from 0.01 to 8.6 mg/L. (Author 's abstract)

Proteomic and metabolomic analyses provide insight into production of volatile and non-volatile flavor components in mandarin hybrid fruit

USDA-ARS?s Scientific Manuscript database

Although many of the volatile constituents of flavor and aroma in citrus have been identified, the molecular mechanism and regulation of volatile production is not well understood. Our aim was to understand mechanisms of flavor volatile production and regulation in mandarin fruit. To this end fruits...

Volatile compounds and sensory properties of Montasio cheese made from the milk of Simmental cows grazing on alpine pastures.

PubMed

Bovolenta, S; Romanzin, A; Corazzin, M; Spanghero, M; Aprea, E; Gasperi, F; Piasentier, E

2014-12-01

The aim of this study was to analyze the volatile compounds, physicochemical characteristics, and sensory properties of Montasio, a semicooked pressed cheese, produced from the milk of the dual-purpose Italian Simmental cows grazing on alpine pastures. A total of 72 cows grazing on 2 pastures, which differed in botanical composition (nutrient-rich pasture vs. nutrient-poor pasture), received 2 different levels of supplementation (3.0 vs 1.5 kg/head per day). The experimental cheeses were produced from whole, raw milk and ripened for 60 d. Sixty-one volatile compounds, including alcohols (11), aldehydes (6), ketones (10), lactones (2), esters (6), hydrocarbons (3), carboxylic acids (6), phenolic compounds (4), monoterpenes (7), sesquiterpenes (1), sulfur compounds (4), and amines (1), were detected. The main families in terms of relative weight appeared to be carboxylic acids, esters, and alcohols. A panel of trained assessors described the experimental cheeses as having an intense color; small and evenly distributed eyes; an intense odor and flavor of milk-sour, milk, and cow; and a tender and creamy texture. The pasture type affected the volatile fraction, particularly ketones, phenolic compounds, and terpenes, which are overall higher in nutrient-poor pastures. A slight effect on the sensory analyses, in particular the effect of the cow attribute on odor and flavor, was perceived by the panelists. The cheeses produced on nutrient-rich pasture had higher b* (yellowness) index. These results were consistent with the color evaluation of the sensory panel. In addition, the pasture affected some textural attributes (adhesivity, creaminess, and granules) as perceived by the panelists. Concentrate supplementation, which is required to meet the feeding requirements of grazing cows, had no clear effect on either the volatile compounds or the sensory properties of the cheeses. Thus, at least within levels of integration adopted, it is expected not to alter the organoleptic characteristics of this product. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Volatility of organic aerosol and its components in the Megacity of Paris

NASA Astrophysics Data System (ADS)

Paciga, A.; Karnezi, E.; Kostenidou, E.; Hildebrandt, L.; Psichoudaki, M.; Engelhart, G. J.; Lee, B.-H.; Crippa, M.; Prévôt, A. S. H.; Baltensperger, U.; Pandis, S. N.

2015-08-01

Using a mass transfer model and the volatility basis set, we estimate the volatility distribution for the organic aerosol (OA) components during summer and winter in Paris, France as part of the collaborative project MEGAPOLI. The concentrations of the OA components as a function of temperature were measured combining data from a thermodenuder and an aerosol mass spectrometer (AMS) with Positive Matrix Factorization (PMF) analysis. The hydrocarbon-like organic aerosol (HOA) had similar volatility distributions for the summer and winter campaigns with half of the material in the saturation concentration bin of 10 μg m-3 and another 35-40 % consisting of low and extremely low volatility organic compounds (LVOCs and ELVOCs, respectively). The winter cooking OA (COA) was more than an order of magnitude less volatile than the summer COA. The low volatility oxygenated OA (LV-OOA) factor detected in the summer had the lowest volatility of all the derived factors and consisted almost exclusively of ELVOCs. The volatility for the semi-volatile oxygenated OA (SV-OOA) was significantly higher than that of the LV-OOA, containing both semi-volatile organic components (SVOCs) and LVOCs. The oxygenated OA (OOA) factor in winter consisted of SVOCs (45 %), LVOCs (25 %) and ELVOCs (30 %). The volatility of marine OA (MOA) was higher than that of the other factors containing around 60 % SVOCs. The biomass burning OA (BBOA) factor contained components with a wide range of volatilities with significant contributions from both SVOCs (50 %) and LVOCs (30 %). Finally, combining the O : C ratio and volatility distributions of the various factors, we incorporated our results into the two-dimensional volatility basis set (2D-VBS). Our results show that the factors cover a broad spectrum of volatilities with no direct link between the average volatility and average O : C of the OA components. Agreement between our findings and previous publications is encouraging for our understanding of the evolution of atmospheric OA.

Volatiles emitted by Carya illinoinensis (Wang.) K. Koch as a prelude for semiochemical investigations to focus on Acrobasis nuxvorella Nuenzig (Lepidoptera: Pyralidae).

PubMed

Corella-Madueño, Maria A; Harris, Marvin K; Fu-Castillo, Agustin A; Martínez-Téllez, Miguel A; Valenzuela-Soto, Elisa M; Gálvez-Ruiz, Juan C; Vargas-Arispuro, Irasema

2011-12-01

Plant volatiles have complex intra- and interspecific effects in the environment that include plant/herbivore interactions. Identifying the quantity and quality of volatiles produced by a plant is needed to aid the process of determining which chemicals are exerting what effects and then examining whether these effects can be manipulated to benefit society. The qualitative characterization of volatile compounds emitted by pecan, Carya illinoinensis (Wang.) K. Koch, was begun in order to establish a database for investigating how these volatiles affect Acrobasis nuxvorella Nuenzig, a monophagous pest of pecan. Headspace solid-phase microextraction combined with gas chromatography-mass spectrometry was used for the analysis of the volatile constituents of pecan during three phenological stages (dormant buds, intact new shoot growth and intact nutlets) of the Western Schley and Wichita cultivars. About 111 distinct compounds were identified from the two cultivars, accounting for ∼99% of the headspace volatiles. The chromatographic profiles of both varieties revealed variations in the volatile composition and proportion between cultivars, with a predominance of terpene hydrocarbons, of the sesquiterpenes class, as well as monoterpenes. The significantly higher responsiveness recorded for the larvae of A. nuxvorella to C. illinoinensis shoots indicates that the larvae may be activated by terpenes emanating from the new shoot growth. This is the first study that has examined volatiles of pecan in Mexico. Copyright © 2011 Society of Chemical Industry.

Thermal removal of pyrene contamination from soil: basic studies and environmental health implications.

PubMed Central

Saito, H H; Bucalá, V; Howard, J B; Peters, W A

1998-01-01

Effects of temperature (400-1000 degrees C) and rate of heating to 550 degrees C (100, 1000, 5000 degrees C/sec) on reduction of pyrene contamination in a Superfund-related soil and on yields of volatile products (tars, CO, CO2, methane, acetylene, ethylene) have been measured. Fifty (+/- 3)-milligram thin layers (less than or equal to 150 micron) of 63- to 125-micron soil particles, neat (i.e., without exogenous chemicals), or pretreated with 4.75 wt% of pyrene, were heated for about 1 to 6 sec, under 3 psig (pounds per in.(2) gauge) of helium in a 12-liter sealed chamber. Pyrene removal, defined as the difference in weight loss of neat versus contaminated soil, was virtually immune to heating rate but increased strongly with increasing temperature, approaching 100% at about 530 degrees C. However, for pyrenepolluted soil, excess soil weight loss and modified CO yields were observed above about 500 degrees C for a 1000 degrees C/sec heating rate. These observations suggest that soil chemical reactions with pyrene or pyrene decomposition products augment soil volatilization. Consequently at elevated temperatures, the difference in weight loss protocol may overestimate polycyclic aromatic hydrocarbon (PAH) removal from soil. Increasing heating rate caused yields of CO, CO(2), and acetylene from pyrene-polluted soil to pass through maxima. Heating neat or contaminated soil resulted in at least two gaseous products of particular environmental interest:acetylene, a precursor to PAH in thermal synthesis, and CO, a toxin to human hemoglobin. Images Figure 1 Figure 2 PMID:9703498

Treatment of industrial exhaust gases by a dielectric barrier discharge

NASA Astrophysics Data System (ADS)

Schmidt, Michael; Hołub, Marcin; Jõgi, Indrek; Sikk, Martin

2016-08-01

Volatile organic compounds (VOCs) in industrial exhaust gases were treated by a dielectric barrier discharge (DBD) operated with two different mobile power supplies. Together with the plasma source various gas diagnostics were used, namely fourier transform infrared (FTIR) spectroscopy, flame ionization detector (FID) and GC-MS. The analysis revealed that some exhaust gases consist of a rather complex mixture of hydrocarbons and inorganic compounds and also vary in pollutants concentration and flow rate. Thus, analysis of removal efficiencies and byproduct concentrations is more demanding than under laboratory conditions. This contribution presents the experimental apparatus used under the harsh conditions of industrial exhaust systems as well as the mobile power source used. Selected results obtained in a shale oil processing plant, a polymer concrete production facility and a yacht hull factory are discussed. In the case of total volatile organic compounds in oil processing units, up to 60% were removed at input energy of 21-37 J/L when the concentrations were below 500 mg/m3. In the yacht hull factory up to 74% of styrene and methanol were removed at specific input energies around 300 J/L. In the polymer concrete production site 195 ppm of styrene were decomposed with the consumption of 1.8 kJ/L. These results demonstrate the feasibility of plasma assisted methods for treatment of VOCs in the investigated production processes but additional analysis is needed to improve the energy efficiency. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

Mechanisms of volatile production from non-sulfur amino acids by irradiation

NASA Astrophysics Data System (ADS)

Ahn, Dong Uk; Lee, Eun Joo; Feng, Xi; Zhang, Wangang; Lee, Ji Hwan; Jo, Cheorun; Nam, Kichang

2016-02-01

Non-sulfur amino acid monomers were used to study the mechanisms of volatile production in meat by irradiation. Irradiation not only produced many volatiles but also increased the amounts of volatiles from non-sulfur amino acid monomers. The major reaction mechanisms involved in volatile production from each group of the amino acids by irradiation differ significantly. However, we speculate that the radiolysis of amino acid side chains were the major mechanism. In addition, Strecker degradation, especially the production of aldehydes from aliphatic group amino acids, and deamination, isomerization, decarboxylation, cyclic reaction and dehydrogenation of the initial radiolytic products were also contributed to the production of volatile compounds. Each amino acid monomers produced different odor characteristics, but the intensities of odor from all non-sulfur amino acid groups were very weak. This indicated that the contribution of volatiles produced from non-sulfur amino acids was minor. If the volatile compounds from non-sulfur amino acids, especially aldehydes, interact with other volatiles compounds such as sulfur compounds, however, they can contribute to the off-odor of irradiated meat significantly.

Atmospheric emissions from the Deepwater Horizon spill constrain air-water partitioning, hydrocarbon fate, and leak rate

NASA Astrophysics Data System (ADS)

Ryerson, T. B.; Aikin, K. C.; Angevine, W. M.; Atlas, E. L.; Blake, D. R.; Brock, C. A.; Fehsenfeld, F. C.; Gao, R.-S.; de Gouw, J. A.; Fahey, D. W.; Holloway, J. S.; Lack, D. A.; Lueb, R. A.; Meinardi, S.; Middlebrook, A. M.; Murphy, D. M.; Neuman, J. A.; Nowak, J. B.; Parrish, D. D.; Peischl, J.; Perring, A. E.; Pollack, I. B.; Ravishankara, A. R.; Roberts, J. M.; Schwarz, J. P.; Spackman, J. R.; Stark, H.; Warneke, C.; Watts, L. A.

2011-04-01

The fate of deepwater releases of gas and oil mixtures is initially determined by solubility and volatility of individual hydrocarbon species; these attributes determine partitioning between air and water. Quantifying this partitioning is necessary to constrain simulations of gas and oil transport, to predict marine bioavailability of different fractions of the gas-oil mixture, and to develop a comprehensive picture of the fate of leaked hydrocarbons in the marine environment. Analysis of airborne atmospheric data shows massive amounts (˜258,000 kg/day) of hydrocarbons evaporating promptly from the Deepwater Horizon spill; these data collected during two research flights constrain air-water partitioning, thus bioavailability and fate, of the leaked fluid. This analysis quantifies the fraction of surfacing hydrocarbons that dissolves in the water column (˜33% by mass), the fraction that does not dissolve, and the fraction that evaporates promptly after surfacing (˜14% by mass). We do not quantify the leaked fraction lacking a surface expression; therefore, calculation of atmospheric mass fluxes provides a lower limit to the total hydrocarbon leak rate of 32,600 to 47,700 barrels of fluid per day, depending on reservoir fluid composition information. This study demonstrates a new approach for rapid-response airborne assessment of future oil spills.

Simulation of SOA formation and composition from oxidation of toluene and m-xylene in chamber experiments

NASA Astrophysics Data System (ADS)

Xu, J.; Liu, Y.; Nakao, S.; Cocker, D.; Griffin, R. J.

2013-12-01

Aromatic hydrocarbons contribute an important fraction of anthropogenic reactive volatile organic compounds (VOCs) in the urban atmosphere. Photo-oxidation of aromatic hydrocarbons leads to secondary organic products that have decreased volatilities or increased solubilities and can form secondary organic aerosol (SOA). Despite the crucial role of aromatic-derived SOA in deteriorating air quality and harming human health, its formation mechanism is not well understood and model simulation of SOA formation still remains difficult. The dependence of aromatic SOA formation on nitrogen oxides (NOx) is not captured fully by most SOA formation models. Most models predict SOA formation under high NOx levels well but underestimate SOA formation under low NOx levels more representative of the ambient atmosphere. Thus, it is crucial to investigate the NOx-dependent chemistry in aromatic photo-oxidation systems and correspondingly update SOA formation models. In this study, NOx-dependent mechanisms of toluene and m-xylene SOA formation are updated using the gas-phase Caltech Atmospheric Chemistry Mechanism (CACM) coupled to a gas/aerosol partitioning model. The updated models were optimized by comparing to eighteen University of California, Riverside United States Environmental Protection Agency (EPA) chamber experiment runs under both high and low NOx conditions. Correction factors for vapor pressures imply uncharacterized aerosol-phase association chemistry. Simulated SOA speciation implies the importance of ring-opening products in governing SOA formation (up to 40%~60% for both aromatics). The newly developed model can predict strong decreases of m-xylene SOA yield with increasing NOx. Speciation distributions under varied NOx levels implies that the well-known competition between RO2 + HO2 and RO2 + NO (RO2 = peroxide bicyclic radical) may not be the only factor influencing SOA formation. The reaction of aromatic peroxy radicals with NO competing with its self-cyclization also affects NOx-dependence of SOA formation. Comparison of SOA formation yield and composition between two aromatics implies aldehyde/ketone chemistry from ring-opening route and chemistry for phenolic route play important roles in governing SOA formation and that ring-opening aldehydes and phenolic nitrates are produced to a greater extent in the toluene system, leading to higher SOA yields for toluene than for m-xylene.

Source Signature of Volatile Organic Compounds (VOCs) associated with oil and natural gas operations in Utah and Colorado

NASA Astrophysics Data System (ADS)

Gilman, J.; Lerner, B. M.; Warneke, C.; Holloway, J. S.; Peischl, J.; Ryerson, T. B.; Young, C. J.; Edwards, P.; Brown, S. S.; Wolfe, D. E.; Williams, E. J.; De Gouw, J. A.

2012-12-01

The U.S. Energy Information Administration has reported a sharp increase in domestic oil and natural gas production from "unconventional" reserves (e.g., shale and tight sands) between 2005 and 2012. The recent growth in drilling and fossil fuel production has led to environmental concerns regarding local air quality. Severe wintertime ozone events (greater than 100 ppb ozone) have been observed in Utah's Uintah Basin and Wyoming's Upper Green River Basin, both of which contain large natural gas fields. Raw natural gas is a mixture of approximately 60-95 mole percent methane while the remaining fraction is composed of volatile organic compounds (VOCs) and other non-hydrocarbon gases. We measured an extensive set of VOCs and other trace gases near two highly active areas of oil and natural gas production in Utah's Uintah Basin and Colorado's Denver-Julesburg Basin in order to characterize primary emissions of VOCs associated with these industrial operations and identify the key VOCs that are precursors for potential ozone formation. UBWOS (Uintah Basin Winter Ozone Study) was conducted in Uintah County located in northeastern Utah in January-February 2012. Two Colorado studies were conducted at NOAA's Boulder Atmospheric Observatory in Weld County in northeastern Colorado in February-March 2011 and July-August 2012 as part of the NACHTT (Nitrogen, Aerosol Composition, and Halogens on a Tall Tower) and SONNE (Summer Ozone Near Natural gas Emissions) field experiments, respectively. The C2-C6 hydrocarbons were greatly enhanced for all of these studies. For example, the average propane mixing ratio observed during the Utah study was 58 ppb (median = 35 ppb, minimum = 0.8, maximum = 520 ppb propane) compared to urban averages which range between 0.3 and 6.0 ppb propane. We compare the ambient air composition from these studies to urban measurements in order to show that the VOC source signature from oil and natural gas operations is distinct and can be clearly distinguished from typical urban emissions associated with on-road combustion sources. We show that each geologic basin has a unique VOC source signature. We will examine the effects of photochemical processing of the primary VOC emissions by comparing the composition and OH reactivity for the wintertime studies to the summertime when there is active photochemistry occurring.

Toluene in sewage and sludge in wastewater treatment plants.

PubMed

Mrowiec, Bozena

2014-01-01

Toluene is a compound that often occurs in municipal wastewater ranging from detectable levels up to 237 μg/L. Before the year 2000, the presence of the aromatic hydrocarbons was assigned only to external sources. The Enhanced Biological Nutrients Removal Processes (EBNRP) work according to many different schemes and technologies. For high-efficiency biological denitrification and dephosphatation processes, the presence of volatile fatty acids (VFAs) in sewage is required. VFAs are the main product of organic matter hydrolysis from sewage sludge. However, no attention has been given to other products of the process. It has been found that in parallel to VFA production, toluene formation occurred. The formation of toluene in municipal anaerobic sludge digestion processes was investigated. Experiments were performed on a laboratory scale using sludge from primary and secondary settling tanks of municipal treatment plants. The concentration of toluene in the digested sludge from primary settling tanks was found to be about 42,000 μg/L. The digested sludge supernatant liquor returned to the biological dephosphatation and denitrification processes for sewage enrichment can contain up to 16,500 μg/L of toluene.

Fast pyrolysis kinetics of alkali lignin: Evaluation of apparent rate parameters and product time evolution.

PubMed

Ojha, Deepak Kumar; Viju, Daniel; Vinu, R

2017-10-01

In this study, the apparent kinetics of fast pyrolysis of alkali lignin was evaluated by obtaining isothermal mass loss data in the timescale of 2-30s at 400-700°C in an analytical pyrolyzer. The data were analyzed using different reaction models to determine the rate constants and apparent rate parameters. First order and one dimensional diffusion models resulted in good fits with experimental data with apparent activation energy of 23kJmol -1 . Kinetic compensation effect was established using a large number of kinetic parameters reported in the literature for pyrolysis of different lignins. The time evolution of the major functional groups in the pyrolysate was analyzed using in situ Fourier transform infrared spectroscopy. Maximum production of the volatiles occurred around 10-12s. A clear transformation of guaiacols to phenol, catechol and their derivatives, and aromatic hydrocarbons was observed with increasing temperature. The plausible reaction steps involved in various transformations are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Natural attenuation of chlorinated hydrocarbons in a freshwater wetland

USGS Publications Warehouse

Lora, Michelle M.; Olsen, Lisa D.; Smith, Barrett L.; Alleman, Bruce C.; Leeson, Andrea

1997-01-01

Natural attenuation of chlorinated volatile organic compounds (VOC's) occurs as ground water discharges from a sand aquifer to a freshwater wetland at Aberdeen Proving Ground, Md. Field and laboratory results indicate that biotransformation in the anaerobic wetland sediments is an important attenuation process. Relatively high concentrations of the parent compounds trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (PCA) and low or undetectable concentrations of daughter products were measured in the aquifer. In contrast, relatively high concentrations of the daughter products cis- and trans-1,2-dichloroethylene (12DCE); vinyl chloride (VC); 1,1,2-trichloroethane (112TCA); and 1,2-dichloroethane (12DCA) were measured in ground water in the wetland sediments, although total VOC concentrations decreased upward from about 1 mu mol/L (micromoles per liter) at the base of the wetland sediments to less than 0.2 near the surface. Microcosm experiments showed that 12DCE and VC are produced from anaerobic degradation of both TCE and PCA; PCA degradation also produced 112TCA and 12DCA.

Lipase catalyzed synthesis of neutral glycerides rich in micronutrients from rice bran oil fatty acid distillate.

PubMed

Nandi, Sumit; Gangopadhyay, Sarbani; Ghosh, Santinath

2008-01-01

Neutral glycerides with micronutrients like sterols, tocopherols and squalene may be prepared from cheap raw material like rice bran oil fatty acid distillate (RBO FAD). RBO FAD is an important byproduct of vegetable oil refining industries in the physical refining process. Glycerides like triacylglycerols (TAG), diacylglycerols (DAG) and monoacylglycerols (MAG) containing significant amounts of unsaponifiable matter like sterols, tocopherols and hydrocarbons (mainly squalene) may certainly be considered as novel functional food ingredients. Fatty acids present in RBO FAD were esterified with glycerol of varying amount (1:0.33, 1:0.5, 1:1 and 1:1.5 of FAD : glycerol ratio) for 8 h using non-specific enzyme NS 40013 (Candida antartica). After esterification the product mixture containing mono, di- and triglycerides was purified by molecular distillation to remove excess free fatty acids and also other volatile undesirable components. The purified product containing sterols, tocopherols and squalene can be utilized in various food formulations.

Temperature-dependent ozone chemiluminescence: A new approach for hydrocarbon monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marley, N.; Gaffney, J.

1996-12-31

Ozone chemiluminescent reactions have been used for some time to detect oxides of nitrogen, ozone, and olefins in air quality studies. Current procedures use non-methane hydrocarbon analyzers based on the flame ionization detector (FID), which quantitate total non-methane hydrocarbons but do not differentiate between the wide variety of volatile organic classes and oxygenates. The other methodology that has been used, gas chromatography/mass spectroscopy (GC/MS), can measure a variety of individual hydrocarbon species and classes, but it is costly, time-consuming, and labor intensive and is not amenable to real-time measurements. Presented here is preliminary research aimed at the development of anmore » alternative to FID and GC/MS: the ozone chemiluminescent detector (OCD) for measurement of a variety of hydrocarbon species and classes by use of the temperature dependence of ozone chemiluminescent reactions. Responses for various hydrocarbon classes obtained with an OCD operated at 170 C or the FID were compared. The results indicate that the OCD detector responds like a total carbon detector at this temperature, with sensitivities 10-100 times higher than those of a FID. Use of the temperature dependence of the chemiluminescent reaction and prereactors will apparently make a real-time hydrocarbon analyzer based on this approach feasible for determination of high-, moderate-, and low-reactivity hydrocarbon levels in ambient air. The OCD approach may be very useful in determining oxygenate emissions from motor vehicles, particularly alternative fuels. The OCD may also be useful in monitoring of ambient air for natural hydrocarbon emissions.« less

Public health assessment for Tutu Wellfield, St. Thomas, St. Thomas County, Virgin Islands. Cerclis No. VID982272569. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-05-14

The Tutu Wellfield National Priorities List (NPL) site is in east-central St. Thomas, U.S. Virgin Island. Twenty-two wells in the Turpentine Run Basin contain at minimum a trace of volatile organic contaminants. Volatile and chlorinated hydrocarbons including benzene; toluene; 1,2-trans-dichloroethene (DCE); trichloroethene (TCE); and tetrachloroethene (PCE) were detected in several of the wells. The Agency for Toxic Substances and Disease Registry (ATSDR) has concluded that the Tutu Wellfield National Priorities List (NPL) site, St. Thomas, U.S. Virgin Islands, poses a public health hazard for past, present, and possible future ingestion of contaminated groundwater.

Volatile aromatic hydrocarbons and dicarboxylic acid concentrations in air at an urban site in the Southwestern US

NASA Astrophysics Data System (ADS)

Tran, Ngoc K.; Steinberg, Spencer M.; Johnson, Brian J.

Concentrations of benzene, toluene, ethylbenzene, o-xylene, and m- and p-xylene were measured at an urban sampling site in Las Vegas, NV by sorbent sampling followed by thermal desorption and determination by GC-PID. Simultaneously, measurements of oxalic, malonic, succinic, and adipic acids were made at the same site by collection on quartz filters, extraction, esterification, and determination by GC-FID. For the period from April 7, 1997 to June 11, 1997, 201 sets of hydrocarbon measurements and 99 sets of acid measurements were made. Additional measurements of dicarboxylic acids were made on samples that represented potential direct sources, e.g. green plants and road dust. Correlations between the hydrocarbon and CO concentrations (measured by the Clark County Health District at a nearby site) were highly significant and a strong negative correlation of hydrocarbon concentration with ozone concentration (also from the county site) was observed under quiescent atmospheric conditions. In general, dicarboxylic acid concentrations were well correlated with one another (with the exception of adipic acid) but not well correlated with hydrocarbon, CO, and ozone concentrations. Multiple sources and complex formation processes are indicated for the dicarboxylic acids.

Hydrocarbon removal from bilgewater by a combination of air-stripping and photocatalysis.

PubMed

Cazoir, D; Fine, L; Ferronato, C; Chovelon, J-M

2012-10-15

In order to prevent hydrocarbon discharge at sea from the bilge of ships, the International Maritime Organization (IMO) enacted the MARPOL 73/78 convention in which effluents are now limited to those with maximum oil content of 15 ppmv. Thus, photocatalysis and air-stripping were combined for the hydrocarbon removal from a real oily bilgewater sample and an original monitoring of both aqueous and gaseous phases was performed by GC/MS to better understand the process. Our results show that the hydrocarbon oil index [HC] can be reduced to its maximum permissible value of 15 ppmv (MARPOL) in only 8.5h when photocatalysis and air-stripping are used together in a synergistic way, as against 17 h when photocatalysis is used alone. However, this air-assisted photocatalytic process emits a large quantity of volatile organic compounds (VOC) and, within the first four hours, ca. 10% of the hydrocarbon removal in the aqueous phase is actually just transferred into the gaseous one. Finally, we highlight that the n-alkanes with a number of carbon atoms higher than 15 (N(C)>15) are those which most decrease the rate of [HC] removal. Copyright © 2012 Elsevier B.V. All rights reserved.

Versatility of hydrocarbon production in cyanobacteria.

PubMed

Xie, Min; Wang, Weihua; Zhang, Weiwen; Chen, Lei; Lu, Xuefeng

2017-02-01

Cyanobacteria are photosynthetic microorganisms using solar energy, H 2 O, and CO 2 as the primary inputs. Compared to plants and eukaryotic microalgae, cyanobacteria are easier to be genetically engineered and possess higher growth rate. Extensive genomic information and well-established genetic platform make cyanobacteria good candidates to build efficient biosynthetic pathways for biofuels and chemicals by genetic engineering. Hydrocarbons are a family of compounds consisting entirely of hydrogen and carbon. Structural diversity of the hydrocarbon family is enabled by variation in chain length, degree of saturation, and rearrangements of the carbon skeleton. The diversified hydrocarbons can be used as valuable chemicals in the field of food, fuels, pharmaceuticals, nutrition, and cosmetics. Hydrocarbon biosynthesis is ubiquitous in bacteria, yeasts, fungi, plants, and insects. A wide variety of pathways for the hydrocarbon biosynthesis have been identified in recent years. Cyanobacteria may be superior chassis for hydrocabon production in a photosynthetic manner. A diversity of hydrocarbons including ethylene, alkanes, alkenes, and terpenes can be produced by cyanobacteria. Metabolic engineering and synthetic biology strategies can be employed to improve hydrocarbon production in cyanobacteria. This review mainly summarizes versatility and perspectives of hydrocarbon production in cyanobacteria.

Environmental Assessment: Installation of Thermally Stable Jet Fuel (JPTS) Above Ground Storage System Westover Air Reserve Base, Chicopee, Massachusetts

DTIC Science & Technology

2004-06-30

gasoline fuels is a result ofleaking USTs in the Aqua System Site (SS-19) to the north. Volatile petroleum hydrocarbon ( VPH ) contamination from the...in- situ enhanced bioremediation plan wilJ be implemented to reduce the concentrations of VPH that are present in soils in the groundwater saturated

Assessing the fate of an aromatic hydrocarbon fluid in agricultural spray applications using the three-stage ADVOCATE model framework

USDA-ARS?s Scientific Manuscript database

Components of emulsifiable concentrates (ECs) used in pesticide formulations may be emitted to air following application in agricultural use and contribute to ozone formation. A key consideration is the fraction of the ECs that is volatilized. This study is designed to provide a mechanistic model fr...

40 CFR 52.1570 - Identification of plan.

Code of Federal Regulations, 2011 CFR

2011-07-01

... hydrocarbon emissions as a result of the revisions to N.J.A.C. 7:27-2.1. (10) Regulation entitled: “Control and Prohibition of Air Pollution by Volatile Organic Substances,” New Jersey Administrative Code (N.J... Protection. (11) Technical justification supporting N.J.A.C. 7:27-16 et seq. submitted on March 3, 1976. (12...

Characterization of Industrial Emission Sources and Photochemistry in Houston, Texas

NASA Astrophysics Data System (ADS)

Washenfelder, R. A.; Atlas, E. L.; Degouw, J.; Flocke, F. M.; Fried, A.; Frost, G. J.; Holloway, J.; Richter, D.; Ryerson, T. B.; Schauffler, S.; Trainer, M.; Walega, J.; Warneke, C.; Weibring, P.; Zheng, W.

2009-12-01

The Houston-Galveston urban area contains a number of large industrial petrochemical emission sources that produce volatile organic compounds and nitrogen oxides. These co-located emissions result in rapid and efficient ozone production downwind. Unlike a single large power plant, the industrial complexes consist of numerous sources that can be difficult to quantify in emission inventories. During September - October 2006, the NOAA WP-3 aircraft conducted research flights as part of the second Texas Air Quality Study (TexAQS II). We examine measurements of NOx, SO2, and speciated hydrocarbons from the Houston Ship Channel, which contains a dense concentration of industrial petrochemical sources, and isolated petrochemical facilities. These measurements are used to derive source emission estimates, which are then compared to available emission inventories. We find that high hydrocarbon emissions are typical for the Houston Ship Channel and isolated petrochemical facilities. Ethene and propene are found to be major contributors to ozone formation. Ratios of C2H4 / NOx and C3H6 / NOx exceed emission inventory values by factors of 10 - 50. These findings are consistent with the first TexAQS study in 2000. We examine trends in C2H4 / NOx and C3H6 / NOx ratios between 2000 and 2006, and determine that day-to-day variability and within-plume variability exceeds any long-term reduction in ethene and propene emissions for the isolated petrochemical sources. We additionally examine downwind photochemical products formed by these alkenes.

27 CFR 21.125 - Rubber hydrocarbon solvent.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rubber hydrocarbon solvent. 21.125 Section 21.125 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative. (b...

27 CFR 21.125 - Rubber hydrocarbon solvent.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Rubber hydrocarbon solvent. 21.125 Section 21.125 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative. (b...

Generation and characterization of gasoline engine exhaust inhalation exposure atmospheres.

PubMed

McDonald, Jacob D; Barr, Edward B; White, Richard K; Kracko, Dean; Chow, Judith C; Zielinska, Barbara; Grosjean, Eric

2008-10-01

Exposure atmospheres for a rodent inhalation toxicology study were generated from the exhaust of a 4.3-L gasoline engine coupled to a dynamometer and operated on an adapted California Unified Driving Cycle. Exposure levels were maintained at three different dilution rates. One chamber at the lowest dilution had particles removed by filtration. Each exposure atmosphere was characterized for particle mass, particle number, particle size distribution, and detailed chemical speciation. The majority of the mass in the exposure atmospheres was gaseous carbon monoxide, nitrogen oxides, and volatile organics, with small amounts of particle-bound carbon/ions and metals. The atmospheres varied according to the cycle, with the largest spikes in volatile organic and inorganic species shown during the "cold start" portion of the cycle. Ammonia present from the exhaust and rodents interacted with the gasoline exhaust to form secondary inorganic particles, and an increase in exhaust resulted in higher proportions of secondary inorganics as a portion of the total particle mass. Particle size had a median of 10-20 nm by number and approximately 150 nm by mass. Volatile organics matched the composition of the fuel, with large proportions of aliphatic and aromatic hydrocarbons coupled to low amounts of oxygenated organics. A new measurement technique revealed organics reacting with nitrogen oxides have likely resulted in measurement bias in previous studies of combustion emissions. Identified and measured particle organic species accounted for about 10% of total organic particle mass and were mostly aliphatic acids and polycyclic aromatic hydrocarbons.

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

PubMed Central

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

2016-01-01

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

Amino Acid Profile and Volatile Flavour Compounds of Raw and Steamed Patin Catfish (Pangasius hypophthalmus) and Narrow-barred Spanish Mackerel (Scomberomorus commerson)

NASA Astrophysics Data System (ADS)

Pratama, Rusky I.; Rostini, I.; Rochima, E.

2018-02-01

Fish species and processing methods could affect the volatile flavour composition and amino acid profile of fishery commodity. The objectives of this study were to identify volatile components and amino acid profile of two considered predominant fish species in Indonesia which are freshwater Patin catfish (Pangasius hypophthalmus) and marine water fish, Spanish mackerel (Scomberomorus commerson). The methods used in this study were to detect volatile compounds using Gas Chromatography/Mass Spectrometry (GC/MS) on fresh and steamed of both species samples (100°C for 30 minutes) and amino acid profile were also analyzed using High Performance Liquid Chromatography (HPLC). The volatile components analysis successfully detects as much as 29 and 59 volatiles compounds in fresh and steamed Patin catfish respectively, while 37 and 102 compounds were detected in fresh and steamed Spanish mackerel samples. Most of detected components derives from hydrocarbons, aldehydes, alcohols and ketone groups which could affected by their chemical composition and resulted from various thermal involved reaction. The amino acids profile identification results showed that glutamic acid was found higher compared to other amino acids standards in both samples. Glutamic acid is non-essential amino acid which is important in umami taste substances.

[Emission of volatile components in carpenter's kumylotox into air].

PubMed

Jodynis-Liebert, J; Kiejnowska, M

1991-01-01

Study was made of Carpenter's Kumylotox, a fungicidal preparation containing: p-cumylphenol, dibutyl phthalate, machine oil, chloroparaffin, a 15% solution of ker-1500 rubber in painter's naphta, and petrol for pastas. The preparation was applied onto boards placed in an experimental chamber at 1-week intervals. In air of the chamber, dibutyl phthalate and p-cumylphenol were determined quantitatively by gas chromatography. The presence of hydrocarbons was recorded by the same method, without quantitative determination. Analyses were continued until the disappearance of the investigated from air. It was found that already after 2 weeks the p-cumylphenol level dropped below the allowable concentration amounting to 0.015 mg/dm3. The dibutyl phthalate level decreased to the allowable concentration (0.05 mg/m3) only after 9 weeks of board ageing. According to analysis by the GC-MS method, aromatic hydrocarbons disappeared from the chamber's air already after 5 weeks, and the remaining hydrocarbons--after 9 weeks.

Heterogeneous Reactions of Limonene on Mineral Dust: Impacts of Adsorbed Water and Nitric Acid.

PubMed

Lederer, Madeline R; Staniec, Allison R; Coates Fuentes, Zoe L; Van Ry, Daryl A; Hinrichs, Ryan Z

2016-12-08

Biogenic volatile organic compounds (BVOCs), including the monoterpene limonene, are a major source of secondary organic aerosol (SOA). While gas-phase oxidation initiates the dominant pathway for BVOC conversion to SOA, recent studies have demonstrated that biogenic hydrocarbons can also directly react with acidic droplets. To investigate whether mineral dust may facilitate similar reactive uptake of biogenic hydrocarbons, we studied the heterogeneous reaction of limonene with mineral substrates using condensed-phase infrared spectroscopy and identified the formation of irreversibly adsorbed organic products. For kaolinite, Arizona Test Dust, and silica at 30% relative humidity, GC-MS identified limonene-1,2-diol as the dominant product with total organic surface concentrations on the order of (3-5) × 10 18 molecules m -2 . Experiments with 18 O-labeled water support a mechanism initiated by oxidation of limonene by surface redox sites forming limonene oxide followed by water addition to the epoxide to form limonenediol. Limonene uptake on α-alumina, γ-alumina, and montmorillonite formed additional products in high yield, including carveol, carvone, limonene oxide, and α-terpineol. To model tropospheric processing of mineral aerosol, we also exposed each mineral substrate to gaseous nitric acid prior to limonene uptake and identified similar surface adsorbed products that were formed at rates 2 to 5 times faster than without nitrate coatings. The initial rate of reaction was linearly dependent on gaseous limonene concentration between 5 × 10 12 and 5 × 10 14 molecules cm -3 (0.22-20.5 ppm) consistent with an Eley-Rideal-type mechanism in which gaseous limonene reacts directly with reactive surface sites. Increasing relative humidity decreased the amount of surface adsorbed products indicating competitive adsorption of surface adsorbed water. Using a laminar flow tube reactor we measured the uptake coefficient for limonene on kaolinite at 25% RH to range from γ = 5.1 × 10 -6 to 9.7 × 10 -7 . After adjusting for reactive surface areas, we estimate uptake coefficients for limonene on HNO 3 -processed mineral aerosol on the order of (1-6) × 10 -6 . Although this heterogeneous reaction will not impact the atmospheric lifetime of gaseous limonene, it does provide a new pathway for mineral aerosol to acquire secondary organic matter from biogenic hydrocarbons, which in turn will alter the physical properties of mineral dust.

Partially oxidised organic components in urban aerosol using GCXGC-TOF/MS

NASA Astrophysics Data System (ADS)

Hamilton, J. F.; Webb, P. J.; Lewis, A. C.; Hopkins, J. R.; Smith, S.; Davy, P.

2004-08-01

Partially oxidised organic compounds associated with PM2.5 aerosol collected in London, England, have been analysed using direct thermal desorption coupled to comprehensive gas chromatography-time of flight mass spectrometry (GCXGC-TOF/MS). Over 10000 individual organic components were isolated from around 10µg of aerosol material in a single procedure and with no sample pre-treatment. Chemical functionalities observed using this analytical technique ranged from alkanes to poly-oxygenated species. The chemical band structures commonly used in GCXGC for group type identifications overlap for this sample type, and have required mass spectrometry as an additional level of instrument dimensionality. An investigation of oxygenated volatile organic compounds (o-VOC) contained within urban aerosol has been performed and in a typical sample around 130 o-VOCs were identified based on retention behaviour and spectral match. In excess of 100 other oxygenated species were also observed but lack of mass spectral library or pure components prevents positive identification. Many of the carbonyl species observed could be mechanistically linked to gas phase aromatic hydrocarbon oxidation and there is good agreement in terms of speciation between the urban samples analysed here and those degradation products observed in smog chamber experiments of aromatic oxidation. The presence of partially oxidised species such as linear chain aldehydes and ketones and cyclic products such as furanones suggests that species generated early in the oxidative process may undergo gas to particle partitioning despite their relatively high volatility.

Partially oxidised organic components in urban aerosol using GCXGC-TOF/MS

NASA Astrophysics Data System (ADS)

Hamilton, J.; Webb, P.; Lewis, A.; Hopkins, J.; Smith, S.; Davy, P.

2004-03-01

Partially oxidised organic compounds associated with PM2.5 aerosol collected in London, England, have been analysed using direct thermal desorption coupled to comprehensive gas chromatography-time of flight mass spectrometry (GCXGC-OF/MS). Over 10 000 individual organic components were isolated from around 10 μg of aerosol material in a single procedure and with no sample pre-treatment. Chemical functionalities observed using this analytical technique ranged from alkanes to poly-oxygenated species. The chemical band structures commonly used in GCXGC for group type identifications overlap for this sample type, and have required mass spectrometry as an additional level of instrument dimensionality. An investigation of oxygenated volatile organic compounds (o-VOC) contained within urban aerosol has been performed and in a typical sample around 130 o-VOCs were identified based on retention behaviour and spectral match. In excess of 100 other oxygenated species were also observed but lack of mass spectral library or pure components prevents positive identification. Many of the carbonyl species observed could be mechanistically linked to gas phase aromatic hydrocarbon oxidation and there is good agreement in terms of speciation between the urban samples analysed here and those degradation products observed in smog chamber experiments of aromatic oxidation. The presence of partially oxidised species such as linear chain aldehydes and ketones and cyclic products such as furanones suggests that species generated relatively early in the oxidative process may undergo gas to particle partitioning despite their relatively high volatility.

Stable Isotope Analyses Suggest Biogenic Hydrocarbon Oxidation is a Major Source of Carbon Monoxide in Summertime Urban Environments

NASA Astrophysics Data System (ADS)

Vimont, I.; Turnbull, J. C.; Petrenko, V. V.; White, J. W. C.

2017-12-01

We present results from a study of carbon monoxide (CO) stable isotopes done at Indianapolis, Indiana as part of the INFLUX project. Our work shows that during the summer, CO production from oxidation of biogenically emitted volatile organic compounds (BVOC's) can equal CO emission from fossil fuel combustion. We hypothesize that the bulk of this VOC-produced CO burden is due to the oxidation of isoprene emitted from trees in, and surrounding, the city of Indianapolis. This result disagrees with modeled CO budget estimates by the Environmental Protection Agency's National Emissions Inventory (EPA NEI). However, recent studies of other gasses, in particular ozone, have produced similar estimates of the BVOC-produced CO burden (Cheng et al., 2017). One likely explanation for this result is the continual reduction of anthropogenic emissions through regulation.

Process for conversion of lignin to reformulated hydrocarbon gasoline

DOEpatents

Shabtai, Joseph S.; Zmierczak, Wlodzimierz W.; Chornet, Esteban

1999-09-28

A process for converting lignin into high-quality reformulated hydrocarbon gasoline compositions in high yields is disclosed. The process is a two-stage, catalytic reaction process that produces a reformulated hydrocarbon gasoline product with a controlled amount of aromatics. In the first stage, a lignin material is subjected to a base-catalyzed depolymerization reaction in the presence of a supercritical alcohol as a reaction medium, to thereby produce a depolymerized lignin product. In the second stage, the depolymerized lignin product is subjected to a sequential two-step hydroprocessing reaction to produce a reformulated hydrocarbon gasoline product. In the first hydroprocessing step, the depolymerized lignin is contacted with a hydrodeoxygenation catalyst to produce a hydrodeoxygenated intermediate product. In the second hydroprocessing step, the hydrodeoxygenated intermediate product is contacted with a hydrocracking/ring hydrogenation catalyst to produce the reformulated hydrocarbon gasoline product which includes various desirable naphthenic and paraffinic compounds.

Engineering organisms for industrial fuel production.

PubMed

Berry, David A

2010-01-01

Volatile fuel costs, the need to reduce greenhouse gas emissions and fuel security concerns are driving efforts to produce sustainable renewable fuels and chemicals. Petroleum comes from sunlight, CO(2) and water converted via a biological intermediate into fuel over a several million year timescale. It stands to reason that using biology to short-circuit this time cycle offers an attractive alternative--but only with relevant products at or below market prices. The state of the art of biological engineering over the past five years has progressed to allow for market needs to drive innovation rather than trying to adapt existing approaches to the market. This report describes two innovations using synthetic biology to dis-intermediate fuel production. LS9 is developing a means to convert biological intermediates such as cellulosic hydrolysates into drop-in hydrocarbon product replacements such as diesel. Joule Unlimited is pioneering approaches to eliminate feedstock dependency by efficiently capturing sunlight, CO(2) and water to produce fuels and chemicals. The innovations behind these companies are built with the market in mind, focused on low cost biosynthesis of existing products of the petroleum industry. Through successful deployment of technologies such as those behind LS9 and Joule Unlimited, alternative sources of petroleum products will mitigate many of the issues faced with our petroleum-based economy. © 2010 Landes Bioscience

Geochemical investigation of the potential for mobilizing non-methane hydrocarbons during carbon dioxide storage in deep coal beds

USGS Publications Warehouse

Kolak, J.J.; Burruss, R.C.

2006-01-01

Coal samples of different rank (lignite to anthracite) were extracted in the laboratory with supercritical CO2 (40 ??C; 10 MPa) to evaluate the potential for mobilizing non-methane hydrocarbons during CO2 storage (sequestration) or enhanced coal bed methane recovery from deep (???1-km depth) coal beds. The total measured alkane concentrations mobilized from the coal samples ranged from 3.0 to 64 g tonne-1 of dry coal. The highest alkane concentration was measured in the lignite sample extract; the lowest was measured in the anthracite sample extract. Substantial concentrations of polycyclic aromatic hydrocarbons (PAHs) were also mobilized from these samples: 3.1 - 91 g tonne-1 of dry coal. The greatest amounts of PAHs were mobilized from the high-volatile bituminous coal samples. The distributions of aliphatic and aromatic hydrocarbons mobilized from the coal samples also varied with rank. In general, these variations mimicked the chemical changes that occur with increasing degrees of coalification and thermal maturation. For example, the amount of PAHs mobilized from coal samples paralleled the general trend of bitumen formation with increasing coal rank. The coal samples yielded hydrocarbons during consecutive extractions with supercritical CO2, although the amount of hydrocarbons mobilized declined with each successive extraction. These results demonstrate that the potential for supercritical CO2 to mobilize non-methane hydrocarbons from coal beds, and the effect of coal rank on this process, are important to consider when evaluating deep coal beds for CO2 storage.

Comparative Analysis of Flower Volatiles from Nine Citrus at Three Blooming Stages

PubMed Central

Azam, Muhammad; Song, Min; Fan, Fangjuan; Zhang, Bo; Xu, Yaying; Xu, Changjie; Chen, Kunsong

2013-01-01

Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME)-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; α-citral and β-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and β-pinene while much lower amount of γ-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; β-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled. PMID:24232454

Comparative analysis of flower volatiles from nine citrus at three blooming stages.

PubMed

Azam, Muhammad; Song, Min; Fan, Fangjuan; Zhang, Bo; Xu, Yaying; Xu, Changjie; Chen, Kunsong

2013-11-13

Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME)-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; α-citral and β-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and β-pinene while much lower amount of γ-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; β-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled.

Air-dust-borne associations of phototrophic and hydrocarbon-utilizing microorganisms: promising consortia in volatile hydrocarbon bioremediation.

PubMed

Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

2012-11-01

Aquatic and terrestrial associations of phototrophic and heterotrophic microorganisms active in hydrocarbon bioremediation have been described earlier. The question arises: do similar consortia also occur in the atmosphere? Dust samples at the height of 15 m were collected from Kuwait City air, and analyzed microbiologically for phototrophic and heterotrophic hydrocarbon-utilizing microorganisms, which were subsequently characterized according to their 16S rRNA gene sequences. The hydrocarbon utilization potential of the heterotrophs alone, and in association with the phototrophic partners, was measured quantitatively. The chlorophyte Gloeotila sp. and the two cyanobacteria Nostoc commune and Leptolyngbya thermalis were found associated with dust, and (for comparison) the cynobacteria Leptolyngbya sp. and Acaryochloris sp. were isolated from coastal water. All phototrophic cultures harbored oil vapor-utilizing bacteria in the magnitude of 10(5) g(-1). Each phototrophic culture had its unique oil-utilizing bacteria; however, the bacterial composition in Leptolyngbya cultures from air and water was similar. The hydrocarbon-utilizing bacteria were affiliated with Acinetobacter sp., Aeromonas caviae, Alcanivorax jadensis, Bacillus asahii, Bacillus pumilus, Marinobacter aquaeolei, Paenibacillus sp., and Stenotrophomonas maltophilia. The nonaxenic cultures, when used as inocula in batch cultures, attenuated crude oil in light and dark, and in the presence of antibiotics and absence of nitrogenous compounds. Aqueous and diethyl ether extracts from the phototrophic cultures enhanced the growth of the pertinent oil-utilizing bacteria in batch cultures, with oil vapor as a sole carbon source. It was concluded that the airborne microbial associations may be effective in bioremediating atmospheric hydrocarbon pollutants in situ. Like the aquatic and terrestrial habitats, the atmosphere contains dust-borne associations of phototrophic and heterotrophic hydrocarbon-utilizing bacteria that are active in hydrocarbon attenuation.

Investigation of the Anti-Melanogenic and Antioxidant Characteristics of Eucalyptus camaldulensis Flower Essential Oil and Determination of Its Chemical Composition.

PubMed

Huang, Huey-Chun; Ho, Ya-Chi; Lim, Jia-Min; Chang, Tzu-Yun; Ho, Chen-Lung; Chang, Tsong-Min

2015-05-07

The effects of essential oil from Eucalyptus camaldulensis flowers oil on melanogenesis and the oil's antioxidant characteristics were investigated. Assays of mushroom and cellular tyrosinase activities and melanin content of mouse melanoma cells were performed spectrophotometrically, and the expression of melanogenesis-related proteins was determined by Western blotting. The possible signaling pathways involved in essential oil-mediated depigmentation were also investigated using specific protein kinase inhibitors. The results revealed that E. camaldulensis flower essential oil effectively suppresses intracellular tyrosinase activity and decreases melanin amount in B16F10 mouse melanoma cells. The essential oil also exhibits antioxidant properties and effectively decreases intracellular reactive oxygen species (ROS) levels. The volatile chemical composition of the essential oil was analyzed with gas chromatography-mass spectrometry (GC/MS). The chemical constituents in the essential oil are predominately oxygenated monoterpenes (34.9%), followed by oxygenated sesquiterpenes (31.8%), monoterpene hydrocarbons (29.0%) and sesquiterpene hydrocarbons (4.3%). Our results indicated that E. camaldulensis flower essential oil inhibits melanogenesis through its antioxidant properties and by down-regulating both mitogen-activated protein kinases (MAPK) and protein kinase A (PKA) signaling pathways. The present study indicates that the essential oil has the potential to be developed into a skin care product.

Manmade organic compounds in the surface waters of the United States: a review of current understanding

USGS Publications Warehouse

Smith, James A.; Witkowski, Patrick J.; Fusillo, Thomas V.

1987-01-01

This report reviews the occurrence and distribution of manmade organic compounds in the surface waters of the United States. On the basis of their aqueous solubilities, nonionic organic compounds partition themselves between water, dissolved organic matter, particulate organic matter, and the lipid reservoirs of aquatic organisms. Ionized organic compounds can be absorbed to sediments, thereby reducing their aqueous concentrations. Transformation processes of photolysis, hydrolysis, biodegradation, and volatilization can attenuate organic compounds, and attenuation rate commonly follow a first-order kinetic process. Eight groups of manmade organic compounds are discussed: 1. Polychlorinated biphenyls and organochlorine insecticides, 2. Carbamate and organophosphorus insecticides, 3. Herbicides, 4. Phenols, 5. Halogenated aliphatic and monocyclic aromatic hydrocarbons, 6. Phthalate esters, 7. Polychlorinated dibenzo-p-dioxins, and 8. Polycyclic aromatic hydrocarbons. For each compound group, data pertaining to use, production, and properties are presented and discussed. Processes that influence that the environmental fate of each group, as determined primarily through laboratory studies, are reviewed, and important fate processes are identified. Environmental concentrations of compounds from each group in water, biota, and sediment are given to demonstrate representative values for comparison to concentrations determined during ongoing research. Finally, where sufficient data exist, regional and temporal contamination trends in the United States are discussed.

Manmade organic compounds in the surface waters of the United States; a review of current understanding

USGS Publications Warehouse

Smith, James A.; Witkowski, P.J.; Fusillo, Thomas V.

1988-01-01

This report reviews the occurrence and distribution of manmade organic compounds in the surface waters of the United States. On the basis of their aqueous solubilities, nonionic organic compounds partition themselves among water, dissolved organic matter, particulate organic matter, and the lipid reservoirs of aquatic organisms. Ionized organic compounds can be adsorbed to sediments, thereby reducing their aqueous concentrations. Transformation processes of photolysis, hydrolysis, biodegradation, and volatilization can attenuate organic compounds, and attenuation rates commonly follow a first-order kinetic process. Eight groups of manmade organic compounds are discussed: 1. Polychlorinated biphenyls and organochlorine insecticides, 2. Carbamate and organophosphorus insecticides, 3. Herbicides, 4. Phenols, 5. Halogenated aliphatic and monocyclic aromatic hydrocarbons, 6. Phthalate esters, 7. Polychlorinated dibenzo-p-dioxins, and 8. Polycyclic aromatic hydrocarbons. For each compound group, data pertaining to use, production, and properties are presented and discussed. Processes that influence the environmental fate of each group, as determined primarily through laboratory studies, are reviewed, and important fate processes are identified. Environmental concentrations of compounds from each group in water, biota, and sediment are given to demonstrate representative values for comparison with concentrations determined during ongoing research. Finally, where data are sufficient, regional and temporal contamination trends in the United States are discussed.

Investigation of the Anti-Melanogenic and Antioxidant Characteristics of Eucalyptus camaldulensis Flower Essential Oil and Determination of Its Chemical Composition

PubMed Central

Huang, Huey-Chun; Ho, Ya-Chi; Lim, Jia-Min; Chang, Tzu-Yun; Ho, Chen-Lung; Chang, Tsong-Min

2015-01-01

The effects of essential oil from Eucalyptus camaldulensis flowers oil on melanogenesis and the oil’s antioxidant characteristics were investigated. Assays of mushroom and cellular tyrosinase activities and melanin content of mouse melanoma cells were performed spectrophotometrically, and the expression of melanogenesis-related proteins was determined by Western blotting. The possible signaling pathways involved in essential oil-mediated depigmentation were also investigated using specific protein kinase inhibitors. The results revealed that E. camaldulensis flower essential oil effectively suppresses intracellular tyrosinase activity and decreases melanin amount in B16F10 mouse melanoma cells. The essential oil also exhibits antioxidant properties and effectively decreases intracellular reactive oxygen species (ROS) levels. The volatile chemical composition of the essential oil was analyzed with gas chromatography–mass spectrometry (GC/MS). The chemical constituents in the essential oil are predominately oxygenated monoterpenes (34.9%), followed by oxygenated sesquiterpenes (31.8%), monoterpene hydrocarbons (29.0%) and sesquiterpene hydrocarbons (4.3%). Our results indicated that E. camaldulensis flower essential oil inhibits melanogenesis through its antioxidant properties and by down-regulating both mitogen-activated protein kinases (MAPK) and protein kinase A (PKA) signaling pathways. The present study indicates that the essential oil has the potential to be developed into a skin care product. PMID:25961954

Survey of Emissions Associated with Enclosed Combustor Emission Control Devices in the Denver-Julesburg Basin

NASA Astrophysics Data System (ADS)

Knighton, W. B.; Floerchinger, C. R.; Wormhoult, J.; Massoli, P.; Fortner, E.; Brooks, B.; Roscioli, J. R.; Bon, D.; Herndon, S. C.

2014-12-01

Volatile organic compounds (VOCs) play an important role in local and regional air quality. A large source of VOCs comes from the oil and gas industry and the Denver-Julesburg Basin (D-J Basin) has seen a sharp increase in production in recent years primarily due to advances in horizontal drilling techniques. To help curb emissions with extraction and production of natural gas and its associated oil, emission control devices are required for facilities emitting over 6 tons of hydrocarbons per year. Within the ozone non-attainment area, which encompasses Denver and much of the front range, enclosed combustion devices (enclosed flares) are required to reduce hydrocarbon emissions by at least 95%. While certification tests indicate that these enclosed combustor devices provide high destruction removal efficiencies, there is considerable interest in knowing how well they perform in the field. As part of Front Range Air Pollution and Photochemistry Experiment (FRAPPE) project conducted during the Summer of 2014, the Aerodyne Mobile Laboratory (AML) surveyed oil and gas operations within the Wattenberg gas field and the surrounding D-J Basin. The AML deployed a full suite of gas and particle phase instrumentation providing a comprehensive set of on-line, real-time measurements for the major natural gas components (methane and ethane) and their combustion products (CO2, CO, NOx) using a variety of spectroscopic techniques. Additional gas phase organic gas emissions were made using a proton transfer reaction mass spectrometer (PTR-MS). Particle number and composition were determined using a condensation particle counter and an Aerodyne Aerosol Mass Spectrometer (AMS). A summary of the number of enclosed combustor devices measured and their observed combustion efficiencies will be presented.

PROPOSED PROCEDURE FOR DERIVATION OF REGULATORY VALUES FOR CARCINOGENIC AIRBORNE POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) BASED ON COAL TAR PITCH (CTP) VOLATILES

EPA Science Inventory

A procedure for estimating upper bound lifetime human cancer risk from air levels of 6 common carcinogenic PAHs, termed "PAHs of concern", is proposed. These PAHs are benzo(a)pyrene, benz(a)anathracene, benzo(k)flouranthene, indeno(1,2,3-c,d)pyrene and chrysene. In application,...

A blend of ethanol and (−)-α-pinene were highly attractive to native siricid woodwasps (Siricidae, Siricinae) infesting conifers of the Sierra Nevada and the Allegheny Mountains

Treesearch

Nadir Erbilgin; Jack D. Stein; Robert E. Acciavatti; Nancy E. Gillette; Sylvia R. Mori; Kristi Bischel; Jonathan A. Cale; Carline R. Carvalho; David L. Wood

2017-01-01

Woodwasps in Sirex and related genera are well-represented in North American conifer forests, but the chemical ecology of native woodwasps is limited to a few studies demonstrating their attraction to volatile host tree compounds, primarily monoterpene hydrocarbons and monoterpene alcohols. Thus, we...

NHEXAS PHASE I MARYLAND STUDY--STANDARD OPERATING PROCEDURE FOR COLLECTION, STORAGE, AND SHIPMENT OF BLOOD SAMPLES FOR METAL, PESTICIDE, PAH, VOC, AND LIPID ANALYSIS (F11)

EPA Science Inventory

The purpose of this SOP is to describe collection, storage, and shipment requirements of blood samples for metal, pesticide, polynuclear aromatic hydrocarbons (PAHs), volatile organic compound (VOC), and lipid analysis. Seven samples were taken from a single puncture: two 3-mL t...

Vapor-Phase Catalytic Oxidation of Mixed Volatile Organic Compounds

DTIC Science & Technology

1989-09-01

18 3. Hopcalite . . . . . . . . . 18 4. Potassium Chloride/Copper Oxide . . . 19 5. Vanadium Pentoxide . . . . . . . 19 6. Potassium...decomposition of 19 halogenated hydrocarbons, associated with submarine burners, using a hopcalite catalyst. Bond, et al. (Reference 9) have studied the...The catalyst can be easily regenerated, but deactivation occurs within a matter of minutes. 3. Hopcalite This mineral, containing primarily CuD and

BOREAS TGB-10 Volatile Organic Carbon Data over the SSA

NASA Technical Reports Server (NTRS)

Westberg, Hal; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Hall, Brad; Jackson, Andrea V.

2000-01-01

The BOREAS TGB-10 team collected several trace gas data sets in its efforts to determine the role of biogenic hydrocarbon emissions with respect to boreal forest carbon cycles. This data set contains measured VOC concentrations. These data were obtained at the SSA-OJP site from May to September 1994. The data are stored in tabular ASCII files.

Essential Oils from Neotropical Piper Species and Their Biological Activities

PubMed Central

da Trindade, Rafaela; Alves, Nayara Sabrina; Figueiredo, Pablo Luís; Maia, José Guilherme S.; Setzer, William N.

2017-01-01

The Piper genus is the most representative of the Piperaceae reaching around 2000 species distributed in the pantropical region. In the Neotropics, its species are represented by herbs, shrubs, and lianas, which are used in traditional medicine to prepare teas and infusions. Its essential oils (EOs) present high yield and are chemically constituted by complex mixtures or the predominance of main volatile constituents. The chemical composition of Piper EOs displays interspecific or intraspecific variations, according to the site of collection or seasonality. The main volatile compounds identified in Piper EOs are monoterpenes hydrocarbons, oxygenated monoterpenoids, sesquiterpene hydrocarbons, oxygenated sesquiterpenoids and large amounts of phenylpropanoids. In this review, we are reporting the biological potential of Piper EOs from the Neotropical region. There are many reports of Piper EOs as antimicrobial agents (fungi and bacteria), antiprotozoal (Leishmania spp., Plasmodium spp., and Trypanosoma spp.), acetylcholinesterase inhibitor, antinociceptive, anti-inflammatory and cytotoxic activity against different tumor cells lines (breast, leukemia, melanoma, gastric, among others). These studies can contribute to the rational and economic exploration of Piper species, once they have been identified as potent natural and alternative sources to treat human diseases. PMID:29240662

Analysis of particle-associated semi-volatile aromatic and aliphatic hydrocarbons in urban particulate matter on a daily basis

NASA Astrophysics Data System (ADS)

Schnelle-Kreis, Jürgen; Sklorz, Martin; Peters, Anette; Cyrys, Josef; Zimmermann, Ralf

PM 2.5 Particle-associated semi-volatile organic compounds (SVOC) were determined in the city of Augsburg, Germany. Daily samples were collected at a central monitoring station from late summer to late autumn 2002. The concentrations of polycyclic aromatic hydrocarbons (PAH), oxidized PAH (O-PAH), n-alkanes, hopanes and long chain linear alkylbenzenes were determined by direct thermal desorption-gas chromatography-time of flight mass spectrometry (DTD-GC-TOFMS). Additionally, PM 2.5 particle mass and number concentrations were measured. The sampling campaign can be divided into two parts, distinguished by a lower temperature level in the second part of the campaign. The particulate mass concentration showed no significant changes, whereas most of the SVOC had significant higher mean and peak concentrations in the colder period. The analysis of the data showed an increased influence of non-traffic sources in the colder period, reflected by a weak shift in the PAH profile and a significant shift in the hopane pattern. Statistical analysis of the inter-group correlations was carried out. Eight clusters partly representing different sources of the aerosol have been identified.

Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds.

PubMed

Schantz, Michele M; Benner, Bruce A; Heckert, N Alan; Sander, Lane C; Sharpless, Katherine E; Vander Pol, Stacy S; Vasquez, Y; Villegas, M; Wise, Stephen A; Alwis, K Udeni; Blount, Benjamin C; Calafat, Antonia M; Li, Zheng; Silva, Manori J; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G; Sjödin, Andreas

2015-04-01

Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers' Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers' Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants.

Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds

PubMed Central

Schantz, Michele M.; Benner, Bruce A.; Heckert, N. Alan; Sander, Lane C.; Sharpless, Katherine E.; Vander Pol, Stacy S.; Vasquez, Y.; Villegas, M.; Wise, Stephen A.; Alwis, K. Udeni; Blount, Benjamin C.; Calafat, Antonia M.; Li, Zheng; Silva, Manori J.; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G.; Sjödin, Andreas

2016-01-01

Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers’ Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers’ Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants. PMID:25651899

A cohort study of intra-urban variations in volatile organic compounds and mortality, Toronto, Canada.

PubMed

Villeneuve, Paul J; Jerrett, Michael; Su, Jason; Burnett, Richard T; Chen, Hong; Brook, Jeffrey; Wheeler, Amanda J; Cakmak, Sabit; Goldberg, Mark S

2013-12-01

This study investigated associations between long-term exposure to ambient volatile organic compounds (VOCs) and mortality. 58,760 Toronto residents (≥35 years of age) were selected from tax filings and followed from 1982 to 2004. Death information was extracted using record linkage to national mortality data. Land-use regression surfaces for benzene, n-hexane, and total hydrocarbons were generated from sampling campaigns in 2002 and 2004 and assigned to residential addresses in 1982. Cox regression was used to estimate relationships between each VOC and non-accidental, cardiovascular, and cancer mortality. Positive associations were observed for each VOC. In multi-pollutant models the benzene and total hydrocarbon signals were strongest for cancer. The hazard ratio for cancer that corresponded to an increase in the interquartile range of benzene (0.13 μg/m(3)) was 1.06 (95% CI = 1.02-1.11). Our findings suggest ambient concentrations of VOCs were associated with cancer mortality, and that these exposures did not confound our previously reported associations between NO2 and cardiovascular mortality. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Volatiles in Inter-Specific Bacterial Interactions

PubMed Central

Tyc, Olaf; Zweers, Hans; de Boer, Wietse; Garbeva, Paolina

2015-01-01

The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well-described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium, and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal, and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide) were tested for their effect on three target bacteria. Here, we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities. PMID:26733959

Volatility of organic aerosol and its components in the megacity of Paris

NASA Astrophysics Data System (ADS)

Paciga, Andrea; Karnezi, Eleni; Kostenidou, Evangelia; Hildebrandt, Lea; Psichoudaki, Magda; Engelhart, Gabriella J.; Lee, Byong-Hyoek; Crippa, Monica; Prévôt, André S. H.; Baltensperger, Urs; Pandis, Spyros N.

2016-02-01

Using a mass transfer model and the volatility basis set, we estimate the volatility distribution for the organic aerosol (OA) components during summer and winter in Paris, France as part of the collaborative project MEGAPOLI. The concentrations of the OA components as a function of temperature were measured combining data from a thermodenuder and an aerosol mass spectrometer (AMS) with Positive Matrix Factorization (PMF) analysis. The hydrocarbon-like organic aerosol (HOA) had similar volatility distributions for the summer and winter campaigns with half of the material in the saturation concentration bin of 10 µg m-3 and another 35-40 % consisting of low and extremely low volatility organic compounds (LVOCs with effective saturation concentrations C* of 10-3-0.1 µg m-3 and ELVOCs C* less or equal than 10-4 µg m-3, respectively). The winter cooking OA (COA) was more than an order of magnitude less volatile than the summer COA. The low-volatility oxygenated OA (LV-OOA) factor detected in the summer had the lowest volatility of all the derived factors and consisted almost exclusively of ELVOCs. The volatility for the semi-volatile oxygenated OA (SV-OOA) was significantly higher than that of the LV-OOA, containing both semi-volatile organic components (SVOCs with C* in the 1-100 µg m-3 range) and LVOCs. The oxygenated OA (OOA) factor in winter consisted of SVOCs (45 %), LVOCs (25 %) and ELVOCs (30 %). The volatility of marine OA (MOA) was higher than that of the other factors containing around 60 % SVOCs. The biomass burning OA (BBOA) factor contained components with a wide range of volatilities with significant contributions from both SVOCs (50 %) and LVOCs (30 %). Finally, combining the bulk average O : C ratios and volatility distributions of the various factors, our results are placed into the two-dimensional volatility basis set (2D-VBS) framework. The OA factors cover a broad spectrum of volatilities with no direct link between the average volatility and average O : C of the OA components.

Apparatus and method for reprocessing and separating spent nuclear fuels. [Patent application

DOEpatents

Krikorian, O.H.; Grens, J.Z.; Parrish, W.H. Sr.

1982-01-19

Spent nuclear fuels, including actinide fuels, volatile and non-volatile fission products, are reprocessed and separated in a molten metal solvent housed in the reaction region of a separation vessel which includes a reflux region positioned above the molten tin solvent. The reflux region minimizes loss of evaporated solvent during the separation of the actinide fuels from the volatile fission products. Additionally, inclusion of the reflux region permits the separation of the more volatile fission products (noncondensable) from the less volatile ones (condensable).

Using chromatography – desorption method of manufacturing gas mixtures for analytical instruments calibration

NASA Astrophysics Data System (ADS)

Platonov, I. A.; Kolesnichenko, I. N.; Lange, P. K.

2018-05-01

In this paper, the chromatography desorption method of obtaining gas mixtures of known compositions stable for a time sufficient to calibrate analytical instruments is considered. The comparative analysis results of the preparation accuracy of gas mixtures with volatile organic compounds using diffusion, polyabarbotage and chromatography desorption methods are presented. It is shown that the application of chromatography desorption devices allows one to obtain gas mixtures that are stable for 10...60 hours in a dynamic condition. These gas mixtures contain volatile aliphatic and aromatic hydrocarbons with a concentration error of no more than 7%. It is shown that it is expedient to use such gas mixtures for analytical instruments calibration (chromatographs, spectrophotometers, etc.)

Generation of Volatile Organic Compounds from Dissolved Organic Matter in far North Atlantic Surface Ocean Waters.

NASA Astrophysics Data System (ADS)

Hudson, E. D.; Ariya, P. A.

2005-12-01

The photochemical degradation of dissolved organic matter (DOM) in surface ocean waters is thought to be a source of volatile organic compounds (VOC) (including non-methane hydrocarbons and low MW carbonyl compounds) to the remote marine troposphere. We report on the characterization of DOM sampled at over 30 sites in the far North Atlantic (Greenland and Norwegian seas, Fram strait) during the summer of 2004, and on experiments to identify factors responsible for the photochemical generation of VOCs in these samples. The results will be discussed in the context of VOC profiles of whole air samples taken to match the seawater samples in time and space.

Low-molecular-weight organoiodine and organobromine compounds released by polar macroalgae--the influence of abiotic factors.

PubMed

Laturnus, F; Giese, B; Wiencke, C; Adams, F C

2000-01-01

The influence of temperature, light, salinity and nutrient availability on the release of volatile halogenated hydrocarbons was investigated in the Antarctic red macroalgal species Gymnogongrus antarcticus Skottsberg. Compared to standard culture condition, an increase in the release rates of iodocompounds was generally found for the exposure of the alga to altered environmental conditions. Macroalgae exhibited higher release rates after adaptation for two months to the changed factors, than after short-term exposure. Monitoring the release rates during a 24 h incubation period (8.25 h light, 15.75 h darkness) showed that changes between light and dark periods had no influence on the release of volatile halocarbons. Compounds like bromoform and 1-iodobutane exhibited constant release rates during the 24 h period. The formation mechanisms and biological role of volatile organohalogens are discussed. Although marine macroalgae are not considered to be the major source of biogenically-produced volatile organohalogens, they contribute significantly to the bromine and iodine cycles in the environment. Under possible environmental changes like global warming and uncontrolled entrophication of the oceans their significance may be increase.

Release of volatile and semi-volatile toxicants during house fires.

PubMed

Hewitt, Fiona; Christou, Antonis; Dickens, Kathryn; Walker, Richard; Stec, Anna A

2017-04-01

Qualitative results are presented from analysis of volatile and semi-volatile organic compounds (VOCs/SVOCs) obtained through sampling of gaseous effluent and condensed particulates during a series of experimental house fires conducted in a real house. Particular emphasis is given to the 16 polycyclic aromatic hydrocarbons (PAHs) listed by the Environmental Protection Agency due to their potentially carcinogenic effects. The initial fuel packages were either cooking oil or a single sofa; these were burned both alone, and in furnished surroundings. Experiments were performed at different ventilation conditions. Qualitative Gas Chromatography-Mass Spectrometry (GC-MS) analysis found VOC/SVOC releases in the developing stages of the fires, and benzo(a)pyrene - the most carcinogenic PAH - was found in at least one sampling interval in the majority of fires. A number of phosphorus fire retardants were detected, in both the gaseous effluent and particulates, from fires where the initial fuel source was a sofa. Their release during the fire is significant as they pose toxicological concerns separate from those presented by the PAHs. Copyright © 2016. Published by Elsevier Ltd.

Perchlorate and Volatiles in the Brine of Lake Vida (antarctica): Implication for the Analysis of Mars Sediments

NASA Astrophysics Data System (ADS)

Kenig, F. P. H.; Chou, L.; McKay, C.; Jackson, W. A.; Doran, P. T.; Murray, A. E.; Fritsen, C. H.

2015-12-01

A cold (-13.4 °C), saline (188 psu) evaporative brine is encapsulated in the thick (> 27 m) ice of Lake Vida (McMurdo Dry Valleys, Antarctica). The Lake Vida brine (LVBr), which contains abundant dissolved organic carbon (48.2 mmol/L), support an active but slow microbial community. LVBr contains oxychlorines with 50 μg/L of perchlorate and 11 μg/L of chlorate. The McMurdo Dry Valleys have often been considered as a good Mars analog. The oxychlorine-rich brine of Lake Vida constitutes a potential equivalent to perchlorate-rich preserved saline liquid water on Mars. We report here on the artifacts created by oxychlorines upon analysis of volatiles and volatile organic compounds (VOCs) of LVBr by direct immersion (DI) and head space (HS) solid phase micro extraction (SPME) gas chromatography-mass spectrometry (GCMS). We compare analytical blanks to a standard containing 40 μg/L of perchlorate and to actual LVBr sample runs. All blanks, perchlorate blanks and samples were analyzed using two types of SPME fibers, CarboxenTM/polydimethylsiloxane (PDMS) and divinylbenzene (DVB)/ PDMS. The similarities and differences between our results and those obtained by the Sample Analysis at Mars instruments of the rover Curiosity are discussed. The volatiles evolved from LVBr upon analysis with DI- and HS-SPME GCMS are dominated by CO2, dichloromethane, HCl, and volatile organic sulfur compounds (VOSCs, such as DMS, DMDS). The volatiles also include oxygenated compounds such as acids and ketones, aromatic compounds, hydrocarbons, chlorinated compounds (dominated by dichloromethane). Apart from the VOSCs, short chain hydrocarbons and some functionalized compounds derived from the brine itself, all compounds observed are artifacts formed upon oxychlorine breakdown in the injector of the GCMS. The distribution of aromatic compounds seems to be directly dependant on the type of SPME fiber used. The perchlorate blanks show a clear pattern of carbon limitation, likely affecting the type and abundance of compounds produced. This suggests that carbon limited perchlorates blanks are not satisfactory for comparison to the analysis of oxychlorine containing samples. Acknowledgment: NASA ASTEP NAG5-12889 (PTD), NSF awards ANT-0739681 (AEM, CHF) and ANT-0739698 (PTD, FK) supported this work.

Quantification and source identification of the Total Elgin gas leak, UK - North Sea, by aircraft sampling

NASA Astrophysics Data System (ADS)

Lee, J. D.; Bauguitte, S.; Wellpott, A.; Lowry, D.; Fisher, R. E.; Lewis, A. C.; Hopkins, J.; Allen, G.; O'Shea, S.; Lanoiselle, M.; France, J.; Lidster, R.; Punjabi, S.; Manning, A. J.; Ryerson, T. B.; Mobbs, S.; Gallagher, M. W.; Coe, H.; Pyle, J. A.; Nisbet, E. G.

2012-12-01

Aircraft measurement and air sampling have been used to quantify the source and magnitude of the North Sea Total Elgin wellhead platform gas leak in March/April 2012. Isotopic techniques were used to characterise the geological source formation from which the gas came. Initially on 30 March 2012 the leak was in the range 1.6 - 0.7 kg s-1, reducing to less than half that rate by 3 April 2012. Keeling plot analysis of methane in air samples showed that the gas had δ13CCH4 -43‰, implying that the gas source was not the main high-pressure high-temperature Elgin gas field (5.5 km deep, at 190oC) but more probably the overlying Hod Formation. The evidence in the air plume for release of very volatile NMHCs confirmed media reports that the gas leak was on the production platform, above the sea level. This contrasts with the early situation in the BP Deepwater Horizon event, where release was underwater and volatile NMHC species were taken up in the water column. Non-methane hydrocarbons (NMHC) and other volatile organic compounds in the plumes were determined from flask samples by offline analysis. NMHC content was dominated by light alkanes ranging from >20 ppb ethane to <1 ppb benzene and <0.1 ppb higher monoaromatics. The methodology developed in this work is widely applicable to future emissions of environmental concern in circumstances where direct access is difficult or dangerous, and permits unbiased regulatory assessment of potential impact, independent of the emitting party.

Taste and aroma of fresh and stored mandarins.

PubMed

Tietel, Zipora; Plotto, Anne; Fallik, Elazar; Lewinsohn, Efraim; Porat, Ron

2011-01-15

During the last decade there has been a continuous rise in consumption of fresh easy-to-peel mandarins. However, mandarins are much more perishable than other citrus fruit, mainly due to rapid deterioration in sensory acceptability after harvest. In the current review we discuss the biochemical components involved in forming the unique flavor of mandarins, and how postharvest storage operations influence taste and aroma and consequently consumer sensory acceptability. What we perceive as mandarin flavor is actually the combination of basic taste, aroma and mouth-feel. The taste of mandarins is principally governed by the levels of sugars and acids in the juice sacs and the relative ratios among them, whereas the aroma of mandarins is derived from a mixture of different aroma volatiles, including alcohols, aldehydes, ketones, terpenes/hydrocarbons and esters. During postharvest storage and marketing there is a gradual decrease in mandarin sensory acceptability, which has been attributed to decreases in acidity and typical mandarin flavor, paralleling an accumulation of off-flavor. Biochemical analysis of volatile and non-volatile constituents in mandarin juice demonstrated that these changes in sensory acceptability were concomitant with decreases in acidity and content of terpenes and aldehydes, which provide green, piney and citrus aroma on the one hand, and increases in ethanol fermentation metabolism products and esters on the other, which are likely to cause 'overripe' and off-flavors. Overall, we demonstrate the vast importance of the genetic background, maturity stage at harvest, commercial postharvest operation treatments, including curing, degreening and waxing, and storage duration on mandarin sensory quality. Copyright © 2010 Society of Chemical Industry.

Cogeneration systems and processes for treating hydrocarbon containing formations

DOEpatents

Vinegar, Harold J [Bellaire, TX; Fowler, Thomas David [Houston, TX; Karanikas, John Michael [Houston, TX

2009-12-29

A system for treating a hydrocarbon containing formation includes a steam and electricity cogeneration facility. At least one injection well is located in a first portion of the formation. The injection well provides steam from the steam and electricity cogeneration facility to the first portion of the formation. At least one production well is located in the first portion of the formation. The production well in the first portion produces first hydrocarbons. At least one electrical heater is located in a second portion of the formation. At least one of the electrical heaters is powered by electricity from the steam and electricity cogeneration facility. At least one production well is located in the second portion of the formation. The production well in the second portion produces second hydrocarbons. The steam and electricity cogeneration facility uses the first hydrocarbons and/or the second hydrocarbons to generate electricity.

Environmental Pollutant Benzo[a]Pyrene Impacts the Volatile Metabolome and Transcriptome of the Human Gut Microbiota.

PubMed

Defois, Clémence; Ratel, Jérémy; Denis, Sylvain; Batut, Bérénice; Beugnot, Réjane; Peyretaillade, Eric; Engel, Erwan; Peyret, Pierre

2017-01-01

Benzo[ a ]pyrene (B[ a ]P) is a ubiquitous, persistent, and carcinogenic pollutant that belongs to the large family of polycyclic aromatic hydrocarbons. Population exposure primarily occurs via contaminated food products, which introduces the pollutant to the digestive tract. Although the metabolism of B[ a ]P by host cells is well known, its impacts on the human gut microbiota, which plays a key role in health and disease, remain unexplored. We performed an in vitro assay using 16S barcoding, metatranscriptomics and volatile metabolomics to study the impact of B[ a ]P on two distinct human fecal microbiota. B[ a ]P exposure did not induce a significant change in the microbial structure; however, it altered the microbial volatolome in a dose-dependent manner. The transcript levels related to several metabolic pathways, such as vitamin and cofactor metabolism, cell wall compound metabolism, DNA repair and replication systems, and aromatic compound metabolism, were upregulated, whereas the transcript levels related to the glycolysis-gluconeogenesis pathway and bacterial chemotaxis toward simple carbohydrates were downregulated. These primary findings show that food pollutants, such as B[ a ]P, alter human gut microbiota activity. The observed shift in the volatolome demonstrates that B[ a ]P induces a specific deviation in the microbial metabolism.

Environmental Pollutant Benzo[a]Pyrene Impacts the Volatile Metabolome and Transcriptome of the Human Gut Microbiota

PubMed Central

Defois, Clémence; Ratel, Jérémy; Denis, Sylvain; Batut, Bérénice; Beugnot, Réjane; Peyretaillade, Eric; Engel, Erwan; Peyret, Pierre

2017-01-01

Benzo[a]pyrene (B[a]P) is a ubiquitous, persistent, and carcinogenic pollutant that belongs to the large family of polycyclic aromatic hydrocarbons. Population exposure primarily occurs via contaminated food products, which introduces the pollutant to the digestive tract. Although the metabolism of B[a]P by host cells is well known, its impacts on the human gut microbiota, which plays a key role in health and disease, remain unexplored. We performed an in vitro assay using 16S barcoding, metatranscriptomics and volatile metabolomics to study the impact of B[a]P on two distinct human fecal microbiota. B[a]P exposure did not induce a significant change in the microbial structure; however, it altered the microbial volatolome in a dose-dependent manner. The transcript levels related to several metabolic pathways, such as vitamin and cofactor metabolism, cell wall compound metabolism, DNA repair and replication systems, and aromatic compound metabolism, were upregulated, whereas the transcript levels related to the glycolysis-gluconeogenesis pathway and bacterial chemotaxis toward simple carbohydrates were downregulated. These primary findings show that food pollutants, such as B[a]P, alter human gut microbiota activity. The observed shift in the volatolome demonstrates that B[a]P induces a specific deviation in the microbial metabolism. PMID:28861070

Characterization and treatment of dissolved organic matter from oilfield produced waters.

PubMed

Wang, Xiaojing; Goual, Lamia; Colberg, Patricia J S

2012-05-30

Dissolved organic matter (DOM) has been studied intensively in streams, lakes and oceans due to its role in the global carbon cycle and because it is a precursor of carcinogenic disinfection by-products in drinking water; however, relatively little research has been conducted on DOM in oilfield produced waters. In this study, recovery of DOM from two oilfield produced waters was relatively low (~34%), possibly due to the presence of high concentrations of volatile organic compounds (VOCs). A van Krevelen diagram of the extracted DOM suggested the presence of high concentrations of lipids, lignin, and proteins, but low concentrations of condensed hydrocarbons. Most of the compounds in the oilfield DOM contained sulfur in their structures. Fourier transform infrared (FTIR) spectra indicated the presence of methyl groups, amides, carboxylic acids, and aromatic compounds, which is in agreement with results of Fourier transform ion cyclotron resonance (FT-ICR) analysis. Qualitatively, DOM in oilfield produced waters is similar to that reported in oceans and freshwater, except that it contains much more sulfur and is less aromatic. Treatment studies conducted in a fluidized bed reactor suggested that volatilization of organics may be a more important mechanism of DOM removal than microbial degradation. Copyright © 2012 Elsevier B.V. All rights reserved.

[Volatile organic compounds concentrations and sources inside new air-conditioned bus].

PubMed

You, Ke-Wei; Ge, Yun-Shan; Qian, Yi-Xin; Liu, Wei; Feng, Bo; Zhang, Yan-Ni; Ning, Zhan-Wu; Hu, Bin; Zhao, Shou-Tang

2008-05-01

The distributing profile and concentration level inside new air-conditioned buses with 53 seats have been determined using the method of thermal desorption-capillary GC/MS under vehicle static conditions. Compounds were identified from their mass spectral data by using US National Institute of Standards and Technology (NIST02). The total numbers of identified components were 33 inside buses, including alkenes (15,45.4%), aromatic compounds (9,27.3%), alcohols (4,12.1%), ketones (3,9.1%) and esters (2,6.1%), especially in the range of C6-C10. The top 5 compounds measured inside buses were decane (8.01 mg/m3), 3-methylhexane (7.10 mg/m3), heptane (5.10 mg/m3), isoheptane (4.20 mg/m3) and 1-Methyl-3-ethylbenzene (3.56 mg/m3), and total volatile organic compounds (TVOC) > 52.5 mg/m3. The main sources of in-vehicle hydrocarbons and aromatic compounds comes from cabin components and interior trim materials (e.g., sealants, carpets, adhesives, paints, leather, plastics, PU foam and PE foam) that may retain certain VOCs during manufacturing, and/or emit these compounds over an extended period of time from off-gassing, aging-related breakdown products, heating/cooling and so on.

Isoprene derived secondary organic aerosol in a global aerosol chemistry climate model

NASA Astrophysics Data System (ADS)

Stadtler, Scarlet; Kühn, Thomas; Taraborrelli, Domenico; Kokkola, Harri; Schultz, Martin

2017-04-01

Secondary organic aerosol (SOA) impacts earth's climate and human health. Since its precursor chemistry and its formation are not fully understood, climate models cannot catch its direct and indirect effects. Global isoprene emissions are higher than any other non-methane hydrocarbons. Therefore, SOA from isoprene-derived, low volatile species (iSOA) is simulated using a global aerosol chemistry climate model ECHAM6-HAM-SALSA-MOZ. Isoprene oxidation in the chemistry model MOZ is following a novel semi-explicit scheme, embedded in a detailed atmospheric chemical mechanism. For iSOA formation four low volatile isoprene oxidation products were identified. The group method by Nanoonlal et al. 2008 was used to estimate their evaporation enthalpies ΔHvap. To calculate the saturation concentration C∗(T) the sectional aerosol model SALSA uses the gas phase concentrations simulated by MOZ and their corresponding ΔHvap to obtain the saturation vapor pressure p∗(T) from the Clausius Clapeyron equation. Subsequently, the saturation concentration is used to calculate the explicit kinetic partitioning of these compounds forming iSOA. Furthermore, the irreversible heterogeneous reactions of IEPOX and glyoxal from isoprene were included. The possibility of reversible heterogeneous uptake was ignored at this stage, leading to an upper estimate of the contribution of glyoxal to iSOA mass.

Emissions of volatile organic compounds during the ship-loading of petroleum products: Dispersion modelling and environmental concerns.

PubMed

Milazzo, Maria Francesca; Ancione, Giuseppa; Lisi, Roberto

2017-12-15

Emissions due to ship-loading of hydrocarbons are currently not addressed neither by the Directive on the integrated pollution prevention or by other environmental regulations. The scope of this study is to point towards the environmental and safety concerns associated with such emissions, even if proper attention has not been given to this issue until now. In order to achieve this goal, the modelling of the emission volatile organic compounds (VOC), due to ship-load operations at refineries has been made by means of the definition of a simulation procedure which includes a proper treatment of the hours of calm. Afterwards, a quantitative analysis of VOC dispersion for an Italian case-study is presented with the primary aims: (i) to develop and verify the validity of the approach for the modelling of the emission sources and of the diffusion of these contaminants into the atmosphere by a proper treatment of the hours of calm and (ii) to identify their contribution to the total VOC emitted in a typical refinery. The calculated iso-concentration contours have also been drawn on a map and allowed the identification of critical areas for people protecting by the adoption of abatement solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Detection of phytoconstituents in column fractions of n-hexane extract of Goldcrest honey exhibiting anti-Helicobacter pylori activity.

PubMed

Manyi-Loh, Christy E; Clarke, Anna M; Ndip, Roland N

2012-04-01

Alternative therapy for Helicobacter pylori eradication from natural products is gaining much attention. This study sought to isolate and characterize the fraction responsible for the antibacterial activity in Goldcrest (GC) n-hexane extract. Thin-layer chromatography (TLC) of the extract was carried out on Silica gel plates to determine the presence of chemical compounds, which were separated and partially purified by column chromatography. The obtained fractions GCCL, GCF2, GCF3 and GCF4 were tested for anti-H. pylori activity using the broth microdilution method. Volatile compounds in the active fractions were identified by gas chromatography-mass spectrometry (GC-MS) analysis. MINITAB was used for statistical analysis at 95% confidence interval. The best antibacterial activity was exhibited by GCF3 (5 mg/mL), which was composed of many compounds with known antimicrobial and antioxidant properties. A total of 16 volatile compounds were identified from fractions GCF2, GCF3 and GCF4 into the following families; alcohol, ketone, aliphatic acid, benzene compound, hydrocarbon, furan and pyran derivatives. The demonstration of antibacterial activity by the column fractions of GC n-hexane extract may provide new lead molecules that could serve as selective agents for H. pylori chemotherapy and control. Copyright © 2012 IMSS. Published by Elsevier Inc. All rights reserved.

Low Earth Orbital Atomic Oxygen Interactions With Materials

NASA Technical Reports Server (NTRS)

Banks, Bruce A.; Miller, Sharon K.; deGroh, Kim K.

2004-01-01

Atomic oxygen is formed in the low Earth orbital environment (LEO) by photo dissociation of diatomic oxygen by short wavelength (< 243 nm) solar radiation which has sufficient energy to break the 5.12 eV O2 diatomic bond in an environment where the mean free path is sufficiently long ( 108 meters) that the probability of reassociation or the formation of ozone (O3) is small. As a consequence, between the altitudes of 180 and 650 km, atomic oxygen is the most abundant species. Spacecraft impact the atomic oxygen resident in LEO with sufficient energy to break hydrocarbon polymer bonds, causing oxidation and thinning of the polymers due to loss of volatile oxidation products. Mitigation techniques, such as the development of materials with improved durability to atomic oxygen attack, as well as atomic oxygen protective coatings, have been employed with varying degrees of success to improve durability of polymers in the LEO environment. Atomic oxygen can also oxidize silicones and silicone contamination to produce non-volatile silica deposits. Such contaminants are present on most LEO missions and can be a threat to performance of optical surfaces. The LEO atomic oxygen environment, its interactions with materials, results of space testing, computational modeling, mitigation techniques, and ground laboratory simulation procedures and issues are presented.

Emissions of volatile organic compounds (VOCs) from the food and drink industries of the European community

NASA Astrophysics Data System (ADS)

Passant, Neil R.; Richardson, Stephen J.; Swannell, Richard P. J.; Gibson, N.; Woodfield, M. J.; van der Lugt, Jan Pieter; Wolsink, Johan H.; Hesselink, Paul G. M.

Estimates were made of the amounts of volatile organic compounds (VOCs) released into the atmosphere as a result of the industrial manufacture and processing of food and drink in the European Community. The estimates were based on a review of literature sources, industrial and government contacts and recent measurements. Data were found on seven food manufacturing sectors (baking, vegetable oil extraction, solid fat processing, animal rendering, fish meal processing, coffee production and sugar beet processing) and three drink manufacturing sectors (brewing, spirit production and wine making). The principle of a data quality label is advocated to illustrate the authors' confidence in the data, and to highlight areas for further research. Emissions of ethanol from bread baking and spirit maturation were found to be the principle sources. However, significant losses of hexane and large quantities of an ill-defined mixture of partially oxidized hydrocarbons were noted principally from seed oil extraction and the drying of plant material, respectively. This latter mixture included low molecular weight aldehydes, carboxylic acids, ketones, amines and esters. However, the precise composition of many emissions were found to be poorly understood. The total emission from the food and drink industry in the EC was calculated as 260 kt yr -1. However, many processes within the target industry were found to be completely uncharacterized and therefore not included in the overall estimate (e.g. soft drink manufacture, production of animal food, flavourings, vinegar, tea, crisps and other fried snacks). Moreover, the use of data quality labels illustrated the fact that many of our estimates were based on limited data. Hence, further emissions monitoring is recommended from identified sources (e.g. processing of sugar beet, solid fat and fish meal) and from uncharacterized sources.

Volatile organic compound (VOC) emissions characterization during the flow-back phase of a hydraulically refractured well in the Uintah Basin, Utah using mobile PTR-MS measurements

NASA Astrophysics Data System (ADS)

Geiger, F.; Warneke, C.; Brown, S. S.; De Gouw, J. A.; Dube, W. P.; Edwards, P.; Gilman, J.; Graus, M.; Helleis, F.; Kofler, J.; Lerner, B. M.; Orphal, J.; Petron, G.; Roberts, J. M.; Zahn, A.

2014-12-01

Ongoing improvements in advanced technologies for crude oil and natural gas extraction from unconventional reserves, such as directional drilling and hydraulic fracturing, have greatly increased the production of fossil fuels within recent years. The latest forecasts even estimate an enhancement of 56% in total natural gas production due to increased development of shale gas, tight gas and offshore natural gas resources from 2012 to 2040 with the largest contribution from shale formations [US EIA: Annual Energy Outlook 2014]. During the field intensive 'Energy and Environment - Uintah Basin Winter Ozone Study (UBWOS)', measurements of volatile organic compounds (VOCs) were made using proton-transfer-reactions mass spectrometry (PTR-MS) at the ground site Horse Pool and using a mobile laboratory in the Uintah Basin, Utah, which is a region well known for intense fossil fuel production. A reworked gas well in the Red Wash fields was sampled regularly within two weeks performing mobile laboratory measurements downwind of the well site. The well had been recently hydraulically refractured at that time and waste water was collected into an open flow-back pond. Very high mixing ratios of aromatic hydrocarbons (C6-C13) up to the ppm range were observed coming from condensate and flow-back reservoirs. The measurements are used to determine sources of specific VOC emissions originating from the different parts of the well site and mass spectra are used to classify the air composition in contrast to samples taken at the Horse Pool field site and crude oil samples from South Louisiana. Enhancement ratios and time series of measured peak values for aromatics showed no clear trend, which indicates changes in emissions with operations at the site.

Volatile aroma components and antioxidant activities of the flavedo peel extract of unripe Shiikuwasha (Citrus depressa Hayata).

PubMed

Asikin, Yonathan; Taira, Ikuko; Inafuku, Sayuri; Sumi, Hidekazu; Sawamura, Masayoshi; Takara, Kensaku; Wada, Koji

2012-04-01

The flavedo peel extracts of unripe Shiikuwasha (Citrus depressa Hayata) fruits were extracted using steam distillation (SD) or a cold-press (CP) system. Volatile aroma content and composition were determined using gas chromatography (GC) and each compound was identified using gas chromatography-mass spectrophotometry (GC-MS). The major constituents of the extracts were monoterpene hydrocarbons (91.75-93.75%[709.32-809.05 mg/100 g of fresh flavedo peel]) including limonene (43.08-45.13%[341.46-379.81 mg/100 g of fresh flavedo peel]), γ-terpinene (27.88-29.06%[219.90-245.86 mg/100 g of fresh flavedo peel]), and p-cymene (8.13-11.02%[61.47-97.22 mg/100 g of fresh flavedo peel]). The extraction process used was determined to be a decisive factor that affects the composition of key citrus aroma components, as well as the antioxidant activities of the Shiikuwasha fruit. Antioxidant capabilities of the extracts were examined by assay of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and β-carotene bleaching inhibition. The cold-press extraction system may better retain the total phenolic content of the flavedo peel and display superior antioxidant activities, compared to the steam distillation extraction method. Shiikuwasha (Citrus depressa Hayata) is a type of small citrus fruit, and has been used as raw material for beverage and food additive productions in Japan. It had a unique aroma composition in which the limonene content of its peels is lower than that of other commonly known citrus peels. The present study detailed the volatile aroma composition, as well as antioxidant capabilities of Shiikuwasha peel extracts of different extraction methods, that are cold-press and steam distillation methods. The results of this study may provide a basis for selection of Shiikuwasha peel extracts in food industry for citrus flavor production. © 2012 Institute of Food Technologists®

Microorganism mediated liquid fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Troiano, Richard

Herein disclosed is a method for producing liquid hydrocarbon product, the method comprising disintegrating a hydrocarbon source; pretreating the disintegrated hydrocarbon source; solubilizing the disintegrated hydrocarbon source to form a slurry comprising a reactant molecule of the hydrocarbon source; admixing a biochemical liquor into the slurry, wherein the biochemical liquor comprises at least one conversion enzyme configured to facilitate bond selective photo-fragmentation of said reactant molecule of the hydrocarbon source, to form liquid hydrocarbons via enzyme assisted bond selective photo-fragmentation, wherein said conversion enzyme comprises reactive sites configured to restrict said reactant molecule such that photo-fragmentation favorably targets a preselectedmore » internal bond of said reactant molecule; separating the liquid hydrocarbons from the slurry, wherein contaminants remain in the slurry; and enriching the liquid hydrocarbons to form a liquid hydrocarbon product. Various aspects of such method/process are also discussed.« less

Fundamental mass transfer modeling of emission of volatile organic compounds from building materials

NASA Astrophysics Data System (ADS)

Bodalal, Awad Saad

In this study, a mass transfer theory based model is presented for characterizing the VOC emissions from building materials. A 3-D diffusion model is developed to describe the emissions of volatile organic compounds (VOCs) from individual sources. Then the formulation is extended to include the emissions from composite sources (system comprising an assemblage of individual sources). The key parameters for the model (The diffusion coefficient of the VOC in the source material D, and the equilibrium partition coefficient k e) were determined independently (model parameters are determined without the use of chamber emission data). This procedure eliminated to a large extent the need for emission testing using environmental chambers, which is costly, time consuming, and may be subject to confounding sink effects. An experimental method is developed and implemented to measure directly the internal diffusion (D) and partition coefficients ( ke). The use of the method is illustrated for three types of VOC's: (i) Aliphatic Hydrocarbons, (ii) Aromatic Hydrocarbons and ( iii) Aldehydes, through typical dry building materials (carpet, plywood, particleboard, vinyl floor tile, gypsum board, sub-floor tile and OSB). Then correlations for predicting D and ke based solely on commonly available properties such as molecular weight and vapour pressure were proposed for each product and type of VOC. These correlations can be used to estimate the D and ke when direct measurement data are not available, and thus facilitate the prediction of VOC emissions from the building materials using mass transfer theory. The VOC emissions from a sub-floor material (made of the recycled automobile tires), and a particleboard are measured and predicted. Finally, a mathematical model to predict the diffusion coefficient through complex sources (floor adhesive) as a function of time was developed. Then this model (for diffusion coefficient in complex sources) was used to predict the emission rate from material system (namely, substrate//glue//vinyl tile).

Recent advances in petroleum microbiology.

PubMed

Van Hamme, Jonathan D; Singh, Ajay; Ward, Owen P

2003-12-01

Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times (<60 s) are being used effectively. Microbes are being injected into partially spent petroleum reservoirs to enhance oil recovery. However, these microbial processes have not exhibited consistent and effective performance, primarily because of our inability to control conditions in the subsurface environment. Microbes may be exploited to break stable oilfield emulsions to produce pipeline quality oil. There is interest in replacing physical oil desulfurization processes with biodesulfurization methods through promotion of selective sulfur removal without degradation of associated carbon moieties. However, since microbes require an environment containing some water, a two-phase oil-water system must be established to optimize contact between the microbes and the hydrocarbon, and such an emulsion is not easily created with viscous crude oil. This challenge may be circumvented by application of the technology to more refined gasoline and diesel substrates, where aqueous-hydrocarbon emulsions are more easily generated. Molecular approaches are being used to broaden the substrate specificity and increase the rates and extents of desulfurization. Bacterial processes are being commercialized for removal of H(2)S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and bacterial biosensors are being used to analyze petroleum-contaminated environments.

Recent Advances in Petroleum Microbiology

PubMed Central

Van Hamme, Jonathan D.; Singh, Ajay; Ward, Owen P.

2003-01-01

Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times (<60 s) are being used effectively. Microbes are being injected into partially spent petroleum reservoirs to enhance oil recovery. However, these microbial processes have not exhibited consistent and effective performance, primarily because of our inability to control conditions in the subsurface environment. Microbes may be exploited to break stable oilfield emulsions to produce pipeline quality oil. There is interest in replacing physical oil desulfurization processes with biodesulfurization methods through promotion of selective sulfur removal without degradation of associated carbon moieties. However, since microbes require an environment containing some water, a two-phase oil-water system must be established to optimize contact between the microbes and the hydrocarbon, and such an emulsion is not easily created with viscous crude oil. This challenge may be circumvented by application of the technology to more refined gasoline and diesel substrates, where aqueous-hydrocarbon emulsions are more easily generated. Molecular approaches are being used to broaden the substrate specificity and increase the rates and extents of desulfurization. Bacterial processes are being commercialized for removal of H2S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and bacterial biosensors are being used to analyze petroleum-contaminated environments. PMID:14665675

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

NASA Astrophysics Data System (ADS)

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

2007-05-01

The profiles of major Volatile organic compounds (VOCs) sources including vehicle exhaust, gasoline vapor, painting, asphalt, liquefied petroleum gas (LPG), biomass burning and petrochemical industry in Pearl River Delta were experimentally determined. Source samples were taken by using dilution chamber for mobile and stationary sources, laboratory simulation for biomass burning. The concentrations of 108 VOC species of sources were quantified by using canister with pre-concentration-GC/MS system, from which 52 PAMS hydrocarbons and one kind of chlorinated hydrocarbon were deployed to build the source profiles for source apportionment of VOCs. Based the measurement of source profiles, the possible tracers for various emission sources were identified, e.g 2-methylbutane and 1,3-butadiene were the tracers for motor vehicle exhaust, the characteristic compounds of architectural and furnishing coatings are aromatics such as toluene and m/p-xylene; the light hydrocarbons, namely n-butane, trans-2-butene and n-pentane, dominated the composition of gasoline vapor; and the nonane, decane and undecane are found to represent the asphalt emissions etc.. The CMB receptor model was applied to source apportionment of 58 hydrocarbons measured at seven sites during the PRD campaign, 2004. The 12 kinds of VOC sources include gasoline/diesel-powered vehicle exhaust, gasoline/diesel headspace vapor, vehicle evaporative emissions, liquid petroleum gas (LPG) leakage, painting vapors, asphalt emission from paved road, biomass burning, coal burning, chemical industry and petroleum refinery. Vehicle exhaust was the largest sources contributing over half of the ambient VOCs at the three urban sites (GuangZhou, FoShan and ZhongShan). LPG leakage played an important role with the percentage of 8- 16% in most sites in PRD. Contributions from solvents usage were highest at DongGuan, an industrial site. At XinKen, the solvents and coatings had the largest percentage of 31% probably due to the influence of its upwind area of DongGuan. The local biomass burning was also found to be a noticeable source at XK.

Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants.

PubMed

Jumpponen, M; Rönkkömäki, H; Pasanen, P; Laitinen, J

2013-01-01

The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

N-nitrosamines as "special case" leachables in a metered dose inhaler drug product.

PubMed

Norwood, Daniel L; Mullis, James O; Feinberg, Thomas N; Davis, Letha K

2009-01-01

N-nitrosamines are chemical entities, some of which are considered to be possible human carcinogens, which can be found at trace levels in some types of foods, tobacco smoke, certain cosmetics, and certain types of rubber. N-nitrosamines are of regulatory concern as leachables in inhalation drug products, particularly metered dose inhalers, which incorporate rubber seals into their container closure systems. The United States Food and Drug Administration considers N-nitrosamines (along with polycyclic aromatic hydrocarbons and 2-mercaptobenzothiazole) to be "special case" leachables in inhalation drug products, meaning that there are no recognized safety or analytical thresholds and these compounds must therefore be identified and quantitated at the lowest practical level. This report presents the development of a quantitative analytical method for target volatile N-nitrosamines in a metered dose inhaler drug product, Atrovent HFA. The method incorporates a target analyte recovery procedure from the drug product matrix with analysis by gas chromatography/thermal energy analysis detection. The capability of the method was investigated with respect to specificity, linearity/range, accuracy (linearity of recovery), precision (repeatability, intermediate precision), limits of quantitation, standard/sample stability, and system suitability. Sample analyses showed that Atrovent HFA contains no target N-nitrosamines at the trace level of 1 ng/canister.

Production Function of Outgassed Volatiles on Mercury: Implications for Polar Volatiles on Mercury and the Moon

NASA Astrophysics Data System (ADS)

Deutsch, A. N.; Head, J. W.

2018-05-01

We are interested in the flux of volatiles delivered to the polar regions of Mercury and the Moon through time. We integrate the production functions for volatile delivery from impacts, solar wind, and volcanism, which we focus on initially.

Farmed and wild sea bass (Dicentrarchus labrax) volatile metabolites: a comparative study by SPME-GC/MS.

PubMed

Vidal, Natalia P; Manzanos, María J; Goicoechea, Encarnación; Guillén, María D

2016-03-15

Farmed and wild European sea bass (Dicentrarchus labrax) could be distinguished by its volatile metabolites, an issue not addressed until now. The aim of this work was to study these metabolites by solid-phase microextraction followed by gas chromatography/mass spectrometry (SPME-GC/MS). Both farmed and wild sea bass have a great number of volatile metabolites, most of them being in low concentrations. These include alcohols, aldehydes, ketones, alkylfurans, acids, aliphatic and aromatic hydrocarbons, terpenes, sulfur and nitrogen derivatives, 2,6-di-tert-butyl-4-methylphenol and one derived compound, as well as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, this latter compound presumably resulting from environmental contamination. Important differences have been detected between both types of sea bass, and also among individuals inside each group. Farmed specimens are richer in volatile metabolites than the wild counterparts; however, these latter, in general, contain a high number and abundance of metabolites resulting from microbial and enzymatic non-oxidative activity than the former. Clear differences in the volatile metabolites of wild and farmed sea bass have been found. A great deal of valuable information on sea bass volatile metabolites has been obtained, which can be useful in understanding certain aspects of the quality and safety of raw and processed sea bass. © 2015 Society of Chemical Industry.

Measurements of volatile organic compounds emitted from plants in the metropolitan area of São Paulo City , Brazil.

NASA Astrophysics Data System (ADS)

Carvalho, L.; Pisani, S.; Pool, C.; Vasconcellos, P.

2003-04-01

The presence of the biogenic hydrocarbons in an NO_x-containing atmosphere can enhance ozone generation and the impact of volatile organic compounds (VOCs) emitted from vegetation on atmospheric chemistry has been investigated. No study of VOC emission rates from plant species has been carried out in São Paulo City, Brazil, prior to this work. This study is part of a three-years project on biogenic volatile organic compounds emissions from species of plants found in the vegetation of the São Paulo metropolitan area. Typical plants (Alchornea sidifolia, Cupania oblongifolia, Cecropia pachystachia, Casearia sylvestris, Machaerium villosum, Croton floribundus, Myrcia rostrata, Solanum erianthum and Ficus insípida) were selected and identical species were studied in urban, sub-urban and forest regions. Biogenic hydrocarbons were determined placing branches of plants in enclosures and measuring the accumulation of emitted compounds in an all-Teflon chamber, the cuvette system. Measuring ambient VOC concentration adsorptive preconcentration, followed by GC-MS after thermal desorption of the sample, was employed to determine components heavier than C_5. Collection of carbonyl compounds on 2, 4-dinitrophenylhydrazine coated particles followed by HPLC-UV was used to analyze low molecular weight carbonyl compounds. Emissions rates of isoprene, a-pinene, camphene and limonene ranged from 0.01 to 2.16 μg C/h.g and emissions rates of aldehydes (C_1 - C_6), acrolein, methacrolein, 2-butanone and acetone ranged from 0.04 to 4.20 μg C/h.g. Ambient and chamber temperatures, relative humidity, light intensity, O_3 and NO_x were monitored during experiments.

Volatility of source apportioned wintertime organic aerosol in the city of Athens

NASA Astrophysics Data System (ADS)

Louvaris, Evangelos E.; Florou, Kalliopi; Karnezi, Eleni; Papanastasiou, Dimitrios K.; Gkatzelis, Georgios I.; Pandis, Spyros N.

2017-06-01

The volatility distribution of ambient organic aerosol (OA) and its components was measured during the winter of 2013 in the city of Athens combining a thermodenuder (TD) and a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). Positive Matrix Factorization (PMF) analysis of both the ambient and the thermodenuder AMS-spectra resulted in a four-factor solution for the OA, namely: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), cooking OA (COA), and oxygenated OA (OOA). The thermograms of the four factors were analyzed and the corresponding volatility distributions were estimated using the volatility basis set (VBS). All four factors included compounds with a wide range of effective volatilities from 10 to less than 10-4 μg m-3 at 298 K. Almost 40% of the HOA consisted of low-volatility organic compounds (LVOCs) with the semi-volatile compounds (SVOCs) representing roughly 30%, while the remaining 30% consisted of extremely low volatility organic compounds (ELVOCs). BBOA was more volatile than the HOA factor on average, with 10% ELVOCs, 40% LVOCs, and 50% SVOCs. 10% of the COA consisted of ELVOCs, another 65% LVOCs, and 50% SVOCs. Finally, the OOA was the least volatile factor and included 40% ELVOCs, 25% LVOCs, and 35% SVOCs. Combining the volatility distributions and the O:C ratios of the various factors, we placed our results in the 2D-VBS analysis framework of Donahue et al. (2012). HOA and BBOA are in the expected region but also include an ELVOC component. COA is in similar range as HOA, but on average is half an order of magnitude more volatile. The OOA in these wintertime conditions had a moderate O:C ratio and included both semi-volatile and extremely low volatility components. The above results are sensitive to the assumed values of the effective vaporization enthalpy and the accommodation coefficient. A reduction of the accommodation coefficient by an order of magnitude or the reduction of the vaporization enthalpy by 20 kJ mol-1 results in the increase of the average volatility by half an order of magnitude.

Methane and benzene in drinking-water wells overlying the Eagle Ford, Fayetteville, and Haynesville Shale hydrocarbon production areas

USGS Publications Warehouse

McMahon, Peter B.; Barlow, Jeannie R.; Engle, Mark A.; Belitz, Kenneth; Ging, Patricia B.; Hunt, Andrew G.; Jurgens, Bryant; Kharaka, Yousif K.; Tollett, Roland W.; Kresse, Timothy M.

2017-01-01

Water wells (n = 116) overlying the Eagle Ford, Fayetteville, and Haynesville Shale hydrocarbon production areas were sampled for chemical, isotopic, and groundwater-age tracers to investigate the occurrence and sources of selected hydrocarbons in groundwater. Methane isotopes and hydrocarbon gas compositions indicate most of the methane in the wells was biogenic and produced by the CO2 reduction pathway, not from thermogenic shale gas. Two samples contained methane from the fermentation pathway that could be associated with hydrocarbon degradation based on their co-occurrence with hydrocarbons such as ethylbenzene and butane. Benzene was detected at low concentrations (<0.15 μg/L), but relatively high frequencies (2.4–13.3% of samples), in the study areas. Eight of nine samples containing benzene had groundwater ages >2500 years, indicating the benzene was from subsurface sources such as natural hydrocarbon migration or leaking hydrocarbon wells. One sample contained benzene that could be from a surface release associated with hydrocarbon production activities based on its age (10 ± 2.4 years) and proximity to hydrocarbon wells. Groundwater travel times inferred from the age-data indicate decades or longer may be needed to fully assess the effects of potential subsurface and surface releases of hydrocarbons on the wells.

Methane and Benzene in Drinking-Water Wells Overlying the Eagle Ford, Fayetteville, and Haynesville Shale Hydrocarbon Production Areas.

PubMed

McMahon, Peter B; Barlow, Jeannie R B; Engle, Mark A; Belitz, Kenneth; Ging, Patricia B; Hunt, Andrew G; Jurgens, Bryant C; Kharaka, Yousif K; Tollett, Roland W; Kresse, Timothy M

2017-06-20

Water wells (n = 116) overlying the Eagle Ford, Fayetteville, and Haynesville Shale hydrocarbon production areas were sampled for chemical, isotopic, and groundwater-age tracers to investigate the occurrence and sources of selected hydrocarbons in groundwater. Methane isotopes and hydrocarbon gas compositions indicate most of the methane in the wells was biogenic and produced by the CO 2 reduction pathway, not from thermogenic shale gas. Two samples contained methane from the fermentation pathway that could be associated with hydrocarbon degradation based on their co-occurrence with hydrocarbons such as ethylbenzene and butane. Benzene was detected at low concentrations (<0.15 μg/L), but relatively high frequencies (2.4-13.3% of samples), in the study areas. Eight of nine samples containing benzene had groundwater ages >2500 years, indicating the benzene was from subsurface sources such as natural hydrocarbon migration or leaking hydrocarbon wells. One sample contained benzene that could be from a surface release associated with hydrocarbon production activities based on its age (10 ± 2.4 years) and proximity to hydrocarbon wells. Groundwater travel times inferred from the age-data indicate decades or longer may be needed to fully assess the effects of potential subsurface and surface releases of hydrocarbons on the wells.

Ethanol Conversion to Hydrocarbons on HZSM-5: Effect of Reaction Conditions and Si/Al Ratio on the Product Distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramasamy, Karthikeyan K.; Wang, Yong

2014-11-17

The Conversion of ethanol to hydrocarbon over HZSM-5 zeolite with different Si/Al ratios was investigated under various reaction conditions. The catalyst with a higher Si/Al ratio (low acid density) deactivated faster and generated more unsaturated compounds at a similar time-on-stream. Temperature affects the catalytic activity with respect to liquid hydrocarbon generation and the hydrocarbon product composition. At lower temperatures (~300°C), the catalyst deactivated faster with respect to the liquid hydrocarbon formation. Higher temperatures (~400°C) reduced the formation of liquid range hydrocarbons and formed more gaseous fractions. Weight hourly space velocity was also found to affect product selectivity with higher weightmore » hourly space velocity leading to a higher extent of ethylene formation. The experimental results were analyzed in terms of the product composition and the coke content with respect to catalyst time-on-stream and compared with the catalyst lifetime with respect to the variables tested on the conversion of ethanol to hydrocarbon.« less

Assessment of bio-fuel options for solid oxide fuel cell applications

NASA Astrophysics Data System (ADS)

Lin, Jiefeng

Rising concerns of inadequate petroleum supply, volatile crude oil price, and adverse environmental impacts from using fossil fuels have spurred the United States to promote bio-fuel domestic production and develop advanced energy systems such as fuel cells. The present dissertation analyzed the bio-fuel applications in a solid oxide fuel cell-based auxiliary power unit from environmental, economic, and technological perspectives. Life cycle assessment integrated with thermodynamics was applied to evaluate the environmental impacts (e.g., greenhouse gas emission, fossil energy consumption) of producing bio-fuels from waste biomass. Landfill gas from municipal solid wastes and biodiesel from waste cooking oil are both suggested as the promising bio-fuel options. A nonlinear optimization model was developed with a multi-objective optimization technique to analyze the economic aspect of biodiesel-ethanol-diesel ternary blends used in transportation sectors and capture the dynamic variables affecting bio-fuel productions and applications (e.g., market disturbances, bio-fuel tax credit, policy changes, fuel specification, and technological innovation). A single-tube catalytic reformer with rhodium/ceria-zirconia catalyst was used for autothermal reformation of various heavy hydrocarbon fuels (e.g., diesel, biodiesel, biodiesel-diesel, and biodiesel-ethanol-diesel) to produce a hydrogen-rich stream reformates suitable for use in solid oxide fuel cell systems. A customized mixing chamber was designed and integrated with the reformer to overcome the technical challenges of heavy hydrocarbon reformation. A thermodynamic analysis, based on total Gibbs free energy minimization, was implemented to optimize the operating environment for the reformations of various fuels. This was complimented by experimental investigations of fuel autothermal reformation. 25% biodiesel blended with 10% ethanol and 65% diesel was determined to be viable fuel for use on a truck travelling with diesel engine and truck idling with fuel cell auxiliary power unit system. The customized nozzle used for fuel vaporization and mixing achieved homogenous atomization of input hydrocarbon fuels (e.g., diesel, biodiesel, diesel-biodiesel blend, and biodiesel-ethanol-diesel), and improved the performance of fuel catalytic reformation. Given the same operating condition (reforming temperature, total oxygen content, water input flow, and gas hourly space velocity), the hydrocarbon reforming performance follows the trend of diesel > biodiesel-ethanol-diesel > diesel-biodiesel blend > biodiesel (i.e., diesel catalytic reformation has the highest hydrogen production, lowest risk of carbon formation, and least possibility of hot spot occurrence). These results provide important new insight into the use of bio-fuels and bio-fuel blends as a primary fuel source for solid oxide fuel cell applications.

The future of oil: unconventional fossil fuels.

PubMed

Chew, Kenneth J

2014-01-13

Unconventional fossil hydrocarbons fall into two categories: resource plays and conversion-sourced hydrocarbons. Resource plays involve the production of accumulations of solid, liquid or gaseous hydro-carbons that have been generated over geological time from organic matter in source rocks. The character of these hydrocarbons may have been modified subsequently, especially in the case of solids and extra-heavy liquids. These unconventional hydrocarbons therefore comprise accumulations of hydrocarbons that are trapped in an unconventional manner and/or whose economic exploitation requires complex and technically advanced production methods. This review focuses primarily on unconventional liquid hydro-carbons. The future potential of unconventional gas, especially shale gas, is also discussed, as it is revolutionizing the energy outlook in North America and elsewhere.

Evaluation of Innovative Volatile Organic Compound and Hazardous Air Pollutant Control Technologies for U.S. Air Force Paint Spray Booths

DTIC Science & Technology

1990-10-01

adsorption/incineration * Membrane vapor separation/condensation * Supercritical fluid oxidation • UV/ozone destruction * Molten salt combustion process...separation/ separate air stream contaminants 9 Oxygenated solvents condensation * Chlorinated hydrocarbons Supercritical fluid * Technology utilizing high...testing or full-scale unit capacity; they are: * Supercritical fluid oxidation • UV/ozone destruction * Molten salt incineration * Infrared incineration

United States Air Force Summer Faculty Research Program. 1981 Program Management Report.

DTIC Science & Technology

1981-10-01

Hydrazine Dr. Albert N. Thompson Methylhydrazine and Unsymdimethylhydrazine with Porphyrins, Metalloporphyrins,’and some Metal Coordination Compounds 79...biodegradation rates, including the nature and concentra- tion of the specific hydrocarbon compound , the species of bacteria present and their quantity...of the importance of biodegradation relative to other loss fac- tors such as volatilization and sediment sorption , and second, the deter- mination of

Advances and challenges in the field of plasma polymer nanoparticles

PubMed Central

Pleskunov, Pavel; Nikitin, Daniil; Titov, Valerii; Shelemin, Artem; Vaidulych, Mykhailo; Kuzminova, Anna; Solař, Pavel; Hanuš, Jan; Kousal, Jaroslav; Kylián, Ondřej; Slavínská, Danka; Biederman, Hynek

2017-01-01

This contribution reviews plasma polymer nanoparticles produced by gas aggregation cluster sources either via plasma polymerization of volatile monomers or via radio frequency (RF) magnetron sputtering of conventional polymers. The formation of hydrocarbon, fluorocarbon, silicon- and nitrogen-containing plasma polymer nanoparticles as well as core@shell nanoparticles based on plasma polymers is discussed with a focus on the development of novel nanostructured surfaces. PMID:29046847

Advances and challenges in the field of plasma polymer nanoparticles.

PubMed

Choukourov, Andrei; Pleskunov, Pavel; Nikitin, Daniil; Titov, Valerii; Shelemin, Artem; Vaidulych, Mykhailo; Kuzminova, Anna; Solař, Pavel; Hanuš, Jan; Kousal, Jaroslav; Kylián, Ondřej; Slavínská, Danka; Biederman, Hynek

2017-01-01

This contribution reviews plasma polymer nanoparticles produced by gas aggregation cluster sources either via plasma polymerization of volatile monomers or via radio frequency (RF) magnetron sputtering of conventional polymers. The formation of hydrocarbon, fluorocarbon, silicon- and nitrogen-containing plasma polymer nanoparticles as well as core@shell nanoparticles based on plasma polymers is discussed with a focus on the development of novel nanostructured surfaces.

Use of On-Site GC/MS Analysis to Distinguish Between Vapor Intrusion and Indoor Sources of VOCs

DTIC Science & Technology

2013-11-01

Toxaphene, Volatile Organics, Acid Extractables, Benzidines, Phthalates, Nitrosamines, Nitroaromatics & Cyclic Ketones , PAHs, Haloethers, Chlorinated...SW 8270), Nitrosamines (SW 8270), Nitroaromatics & Cyclic Ketones (SW 8270), PAHs (SW 8270), Haloethers (SW 8270), Chlorinated Hydrocarbons (SW 8270...alpha-BHC, beta-BHC, gamma-BHC, delta-BHC, Dieldrin, DDD, DDE, DDT,Endosulfan I, Endosulfan II, Endosulfan sulfate, Endrin, Endrin Aldehyde

[Analysis of Volatile Oils from Different Processed Products of Zingiber officinale Rhizome by GC-MS].

PubMed

Zhao, Hong-bing; Wang, Zhi-hui; He, Fang; Meng, Han; Peng, Jian-hua; Shi, Ji-lian

2015-04-01

To analyze the volatile components in different processed products of Zingiber officinale rhizome, and to make clear the effect of different heating degree on them. The volatile components were extracted from four kinds of processed products by applying steam distillation, and then were analyzed by GC-MS. There were totally 43 components of volatile oil identified from four kinds of processed products of Zingiber officinale rhizome. Fresh product, dried product, and charcoal product of Zingiber officinale rhizome each had 27 components of volatile oil, while sand fried product contained 24 components. Fresh Zingiber officinale rhizome contained 22. 59% of zingiberene, 20. 87% of a-citral and 11. 01% of β-phellandrene, respectively. After processing in different heating degree, the volatile components changed greatly in both of their quantity and quality, For instance, dried Zingiber officinale rhizome contained 40. 48% of α-citral and 8-phellandrene content was slightly lower at 10. 38%. 32.73% of 3,7,11-trimethyl-l, 6, 10-dodecatriene,16. 38% of murolan-3, 9 (11)-diene-10-peroxy and 3. 36% of cubebene newly emerged in the sand fried Zingiber officinale rhizome, and eudesm-4 (14) and β-bisabolol, etc. However, β-phellandrene content was only 1. 95%. The zingiberene and β-sesquiphellandrene were the highest in charcoal product, besides, new components such as α-cedrene, decanal and γ-elemene appeared. Volatile components in different processed products of Zingiber officinale rhizome were different in both of their kinds and contents. This method is suitable for the analysis of volatile components in Zingiber officinale rhizome, and this study can provide the experimental evidence for quality evaluation and clinical application for ginger processed products.

Catalytic distillation water recovery subsystem

NASA Technical Reports Server (NTRS)

Budininkas, P.; Rasouli, F.

1985-01-01

An integrated engineering breadboard subsystem for the recovery of potable water from untreated urine based on the vapor phase catalytic ammonia removal was designed, fabricated and tested. Unlike other evaporative methods, this process catalytically oxidizes ammonia and volatile hydrocarbons vaporizing with water to innocuous products; therefore, no pretreatment of urine is required. Since the subsystem is fabricated from commercially available components, its volume, weight and power requirements are not optimized; however, it is suitable for zero-g operation. The testing program consists of parametric tests, one month of daily tests and a continuous test of 168 hours duration. The recovered water is clear, odorless, low in ammonia and organic carbon, and requires only an adjustment of its pH to meet potable water standards. The obtained data indicate that the vapor phase catalytic ammonia removal process, if further developed, would also be competitive with other water recovery systems in weight, volume and power requirements.

Natural and synthetic oviposition stimulants forCatolaccus grandis (Burks) females.

PubMed

Guerra, A A; Martinez, S; Sonia Del Rio, H

1994-07-01

Oviposition behavior was elicited fromCatolaccus grandis (Burks) (Hymenoptera: Pteromalidae) females, an ectoparasitoid of the boll weevil,Anthonomus grandis Boheman (Coleoptera: Curculionidae), by smears of freshly cut cotton bolls or smears of extracts prepared with boll weevil damaged or undamaged cotton boll tissues. Oviposition behavior was also elicited fromC. grandis females by smears made withn-pentane,n-hexane,n-heptane, and isooctane. This is the first report of oviposition behavior elicited for any parasitoid by these short-chain saturated hydrocarbons (alkanes), introducing a new concept on the chemical mediation of parasitoid behavior during host selection. Oviposition behavior was also elicited fromC. grandis females by volatiles emanating from an artificial diet devoid of insect components that was specifically developed for the in vitro rearing of ectoparasitoids. The possible use of a synergistic combination ofn-hexane and diet to optimize the mechanized production of noncontaminated eggs is also discussed.

Cometary material and the origins of life on earth

NASA Technical Reports Server (NTRS)

Lazcano-Araujo, A.; Oro, J.

1981-01-01

The role of cometary material in determining the environmental conditions of the prebiotic earth is reviewed. The organic synthesis pathways that occur in dense interstellar clouds and in comets are examined, and complex organic molecules believed to exist (amino acids, carboxylic acids, purines, pyrimidines and hydrocarbons) based on spectral detections of degradation products are noted. Estimates of the amount of terrestrial volatiles of cometary origin that may have been acquired in collisions during the early history of the earth are considered, and shown to dominate any estimated contributions to terrestrial carbon from other extraterrestrial sources. Current evidence that the origin and early evolution of life began about four billion years ago is discussed in relation to the cometary bombardment processes occurring at the time and the resultant shock waves, reducing atmospheres and reactive chemical species. It is thus concluded that comets contributed significantly to the processes of chemical evolution necessary for the emergence of life on earth.

Kidney cancer and hydrocarbon exposures among petroleum refinery workers.

PubMed

Poole, C; Dreyer, N A; Satterfield, M H; Levin, L; Rothman, K J

1993-12-01

To evaluate the hypothesis of increased kidney cancer risk after exposure to hydrocarbons, especially those present in gasoline, we conducted a case-control study in a cohort of approximately 100,000 male refinery workers from five petroleum companies. A review of 18,323 death certificates identified 102 kidney cancer cases, to each of whom four controls were matched by refinery location and decade of birth. Work histories, containing an average of 15.7 job assignments per subject, were found for 98% of the cases and 94% of the controls. To each job, industrial hygienists assigned semiquantitative ratings for the intensity and frequency of exposures to three hydrocarbon categories: nonaromatic liquid gasoline distillates, aromatic hydrocarbons, and the more volatile hydrocarbons. Ratings of "present" or "absent" were assigned for seven additional exposures: higher boiling hydrocarbons, polynuclear aromatic hydrocarbons, asbestos, chlorinated solvents, ionizing radiation, and lead. Each exposure had either no association or a weak association with kidney cancer. For the hydrocarbon category of principal a priori interest, the nonaromatic liquid gasoline distillates, the estimated relative risk (RR) for any exposure above refinery background was 1.0 (95% confidence interval [CI] 0.5-1.9). Analyses of cumulative exposures and of exposures in varying time periods before kidney cancer occurrence also produced null or near-null results. In an analysis of the longest job held by each subject (average duration 9.2 years or 40% of the refinery work history), three groups appeared to be at increased risk: laborers (RR = 1.9, 95% CI 1.0-3.9); workers in receipt, storage, and movements (RR = 2.5, 95% CI 0.9-6.6); and unit cleaners (RR = 2.3, 95% CI 0.5-9.9).

Space-weathering processes and products on volatile-rich asteroids

NASA Astrophysics Data System (ADS)

Britt, D.; Schelling, P.; Consolmagno, G.; Bradley, T.

2014-07-01

Space weathering is a generic term for the effects on atmosphereless solid bodies in the solar system from a range of processes associated with direct exposure to the space environment. These include impact processes (shock, vaporization, fragmentation, heating, melting, and ejecta formation), radiation damage (from galactic and solar cosmic rays), solar-wind effects (irradiation, ion implantation, and sputtering), and the chemical reactions driven by these processes. The classic example of space weathering is the formation of the lunar spectral red slope associated with the production of nanophase Fe (npFe0) in the dusty lunar regolith (C.R. Chapman, 2004, Annual Review of Earth & Planet. Sci. 32, C.M. Pieters, 2000, MAPS 35). Similar npFe0 has been recovered from asteroid (25143) Itokawa and some asteroid classes do exhibit modest spectral red slopes (T. Noguchi, 2011, Science 333). Space weathering can be thought of as driven by a combination of the chemical environment of space (hard vacuum, low oxygen fugacity, solar-wind implantation of hydrogen) along with thermal energy supplied by micrometeorite impacts. The forward modeling of space weathering as thermodynamically-driven decomposition of common rock-forming minerals suggests the production of a range of daughter products: (1) The silicate products typically lose oxygen, other volatile elements (i.e., sulfur and sodium), and metallic cations, producing minerals that are typically more disordered and less optically active than the original parent materials. (2) The decomposed metallic cations form in nano-sized blebs including npFe0, on the surfaces or in condensing rims of mineral grains. This creates a powerful optical component as seen in the lunar red slope. Surfaces with exposed npFe0 are an ideal environment for catalyzing further reactions. (3) The liberated volatile elements and gases (O, S, Na) may form an observable exosphere (e.g., Moon and Mercury) and can either escape from the body or recombine with available solar-wind-implanted hydrogen to form trace amounts of water and OH. Mineral decomposition can be thought of as the first stage of space weathering. It produces weathered surfaces somewhat depleted in volatile elements, creates a predictable set of minor or trace minerals, and leaves the surfaces with catalytic species, primarily npFe0. However, a second stage of further reactions and weathering depends upon the presence of ''feed-stock'' components that can participate in catalyzed chemical reactions on exposed surfaces. For volatile-rich small bodies, the available materials are not only silicates, but a volatile feedstock that can include water, carbon monoxide, ammonia, to name a few. Thermodynamically-driven decomposition of silicates will produce trace amounts of npFe0 which are ideal sites for Fischer-Tropsch type (FTT) catalytic reactions that can produce organics in situ on the asteroids including alkanes, polyaromatic hydrocarbons, and amino acids (J.E. Elsila, 2012, MAPS 47). The mix and range of products depends on the composition and morphology of the mineral surface, energy inputs produced by the micrometeorite impacts or other processes, and the composition of the input volatile feedstock. FFT reactions generate long-chain carbon compounds and amino acids. Secondary reactions that generate more complex carbon compounds and amino acids are likely to occur as the organic material matures. Weathering maturity can be thought of as a function of the abundance and diversity of the weathering products. Since the npFe0 is not destroyed in the reaction, continued micrometeorite bombardment would result in continuing processing and recombination of the existing organic feedstock. More weathering would result in progressively longer-chain carbon compounds as well as more complex and diverse amino acids, and eventually the kerogen-like insoluble-organic matter that forms a large fraction of carbonaceous meteorites. This insight has several major implications for our planetary science and, potentially, the formation of the precursors of life. First, the range of weathering products seen in remotely-sensed data, meteorites, and returned samples are not random, but the predictable outcome of the source region's mineral kinetics and chemical feedstock. Weathering products do not have to be optically active like the npFe0 that produces the lunar red slope; on the contrary, probably most weathering products are spectrally neutral or even suppress an object's near-IR reflectance spectrum. In the case of volatile-rich parent bodies, a major weathering product is a range of carbon-rich compounds. But an additional result of considerable interest is the generation of pre-biotic compounds as a routine and predictable byproduct of common space-weathering processes. Any atmosphereless body around any star with mafic silicate mineral compositions and volatile feedstocks should create amino acids as a standard byproduct of space weathering. The precursors of life are probably abundant in any space-weathered asteroid belt, in any solar system, and only wait being accreted to a hospitable environment.

Reassessing the ratio of glyoxal to formaldehyde as an indicator of hydrocarbon precursor speciation

NASA Astrophysics Data System (ADS)

Kaiser, J.; Wolfe, G. M.; Min, K. E.; Brown, S. S.; Miller, C. C.; Jacob, D. J.; deGouw, J. A.; Graus, M.; Hanisco, T. F.; Holloway, J.; Peischl, J.; Pollack, I. B.; Ryerson, T. B.; Warneke, C.; Washenfelder, R. A.; Keutsch, F. N.

2015-07-01

The yield of formaldehyde (HCHO) and glyoxal (CHOCHO) from oxidation of volatile organic compounds (VOCs) depends on precursor VOC structure and the concentration of NOx (NOx = NO + NO2). Previous work has proposed that the ratio of CHOCHO to HCHO (RGF) can be used as an indicator of precursor VOC speciation, and absolute concentrations of the CHOCHO and HCHO as indicators of NOx. Because this metric is measurable by satellite, it is potentially useful on a global scale; however, absolute values and trends in RGF have differed between satellite and ground-based observations. To investigate potential causes of previous discrepancies and the usefulness of this ratio, we present measurements of CHOCHO and HCHO over the southeastern United States (SE US) from the 2013 SENEX (Southeast Nexus) flight campaign, and compare these measurements with OMI (Ozone Monitoring Instrument) satellite retrievals. High time-resolution flight measurements show that high RGF is associated with monoterpene emissions, low RGF is associated with isoprene oxidation, and emissions associated with oil and gas production can lead to small-scale variation in regional RGF. During the summertime in the SE US, RGF is not a reliable diagnostic of anthropogenic VOC emissions, as HCHO and CHOCHO production are dominated by isoprene oxidation. Our results show that the new CHOCHO retrieval algorithm reduces the previous disagreement between satellite and in situ RGF observations. As the absolute values and trends in RGF observed during SENEX are largely reproduced by OMI observations, we conclude that satellite-based observations of RGF can be used alongside knowledge of land use as a global diagnostic of dominant hydrocarbon speciation.

On-board generation of a highly volatile starting fuel to reduce automobile cold-start emissions.

PubMed

Ashford, Marcus D; Matthews, Ronald D

2006-09-15

The on-board distillation system (OBDS) was developed to extract, from gasoline, a high-volatility fuel for exclusive use during the starting and warm-up periods. The use of OBDS distillate fuel results in much improved mixture preparation, allowing combinations of air/fuel ratio and ignition timing that are not possible with gasoline, even with a fully warm engine. The volatility of the distillate is a function of the parent fuel volatility; however, the variability in distillate quality can be diminished via manipulation of the OBDS operating conditions. Thus, it is possible to develop aggressive starting calibrations that are relatively immune to variations in pump gasoline volatility. The key benefits provided bythe OBDS fuel relative to standard gasoline were found to be (1) improved mixture preparation allowing a 70% reduction of cranking fuel requirements, elimination of air-fuel mixture enrichment during the warm-up period, and significant extension of warm-up ignition timing retard; (2) a 57% decrease in catalyst light-off time, (3) emissions reductions over the FTP drive cycle of 81% for regulated hydrocarbons (NMOG); (4) emissions index (NMOG) approaching that of SULEV/PZEV vehicles; and (5) an apparent 1% increase in fuel economy over the FTP drive cycle.

Characterization of the Key Aroma Compounds in Proso Millet Wine Using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry.

PubMed

Liu, Jingke; Zhao, Wei; Li, Shaohui; Zhang, Aixia; Zhang, Yuzong; Liu, Songyan

2018-02-20

The volatile compounds in proso millet wine were extracted by headspace solid-phase microextraction (85 μm polyacrylate (PA), 100 μm polydimethylsiloxane (PDMS), 75 μm Carboxen (CAR)/PDMS, and 50/30 μm divinylbenzene (DVB)/CAR/PDMS fibers), and analyzed using gas chromatography-mass spectrometry; the odor characteristics and intensities were analyzed by the odor activity value (OAV). Different sample preparation factors were used to optimize this method: sample amount, extraction time, extraction temperature, and content of NaCl. A total of 64 volatile compounds were identified from the wine sample, including 14 esters, seven alcohols, five aldehydes, five ketones, 12 benzene derivatives, 12 hydrocarbons, two terpenes, three phenols, two acids, and two heterocycles. Ethyl benzeneacetate, phenylethyl alcohol, and benzaldehyde were the main volatile compounds found in the samples. According to their OAVs, 14 volatile compounds were determined to be odor-active compounds (OAV > 1), and benzaldehyde, benzeneacetaldehyde, 1-methyl-naphthalene, 2-methyl-naphthalene, and biphenyl were the prominent odor-active compounds (OAV > 50), having a high OAV. Principal component analysis (PCA) showed the difference of distribution of the 64 volatile compounds and 14 odor-active compounds with four solid-phase microextraction (SPME) fibers.

Characterization of hydrocarbons, halocarbons and carbonyls in the atmosphere of Hong Kong.

PubMed

Guo, H; Lee, S C; Louie, P K K; Ho, K F

2004-12-01

Ambient air quality measurements of 156 species including 39 alkanes, 32 alkenes, 2 alkynes, 24 aromatic hydrocarbons, 43 halocarbons and 16 carbonyls, were carried out for 120 air samples collected at two sampling stations (CW and TW) in 2001 throughout Hong Kong. Spatial variations of volatile organic compounds (VOCs) in the atmosphere were investigated. Levels of most alkanes and alkenes at TW site were higher than that at the CW site, while the BTEX concentrations at the two sites were close. The BTEX ratios at CW and TW were 1.6:10.1:1.0:1.6 and 2.1:10.8:1.0:2.0, respectively. For major halogenated hydrocarbons, the mean concentrations of chloromethane, CFCs 12 and 22 did not show spatial variations at the two sites. However, site-specific differences were observed for trichloroethene and tetrachloroethene. Furthermore, there were no significant differences for carbonyls such as formaldehyde, acetaldehyde and acetone between the two sites. The levels of selected hydrocarbons in winter were 1-5 times that in summer. There were no common seasonal trends for carbonyls in Hong Kong. The ambient level of formaldehyde, the most abundant carbonyl, was higher in summer. However, levels of acetaldehyde, acetone and benzaldehyde in winter were 1.6-3.8 times that in summer. The levels of CFCs 11 and 12, and chloromethane in summer were higher than that in winter. Strong correlation of most hydrocarbons with propene and n-butane suggested that the primary contributors of hydrocarbons were vehicular emissions in Hong Kong. In addition, gasoline evaporation, use of solvents, leakage of liquefied petroleum gas (LPG), natural gas leakage and other industrial emissions, and even biogenic emissions affected the ambient levels of hydrocarbons. The sources of halocarbons were mainly materials used in industrial processes and as solvents. Correlation analysis suggested that photochemical reactions made significant contributions to the ambient levels of carbonyls in summer whereas in winter motor vehicle emissions would be the major sources of the carbonyls. The photochemical reactivity of selected VOCs was estimated in this study. The largest contributors to ozone formation were formaldehyde, toluene, propene, m,p-xylene, acetaldehyde, 1-butene/i-butene, isoprene and n-butane, suggesting that motor vehicles, gasoline evaporation, use of solvents, leakage of LPG, photochemical processes and biogenic emission are sources in the production of ozone. On the other hand, VOCs from vehicles and gasoline evaporation were predominant with respect to reactions with OH radical.

Regional-scale simulation of transport and transformations of semi-volatile polycyclic aromatic hydrocarbons (PAHs) in East Asia: diurnal variations investigation

NASA Astrophysics Data System (ADS)

Mu, Qing; Lammel, Gerhard; Cheng, Yafang

2015-04-01

Semi-volatile PAHs are major pollutants of urban air, mostly regionally transported and reaching remote environments[1]. Some semi-volatile PAHs are carcinogenic. About 22% of global PAHs emissions are in China. The transport and sinks (atmospheric reactions, deposition) of semi-volatile PAHs in East Asia are studied using a modified version of the Weather Research and Forecasting model coupled with chemistry (WRF/Chem [2]). For this purpose, PAHs' gas and particulate phase chemical reactions and dry and wet deposition processes are included. We use emissions of 2008 [3] which include technical combustion processes (coal, oil, gas, waste and biomass) and open fires and apply diurnal time functions as those of black carbon. The model was run for phenanthrene (3-ring PAH, p = 1.5×10-2 Pa at 298 K) and benzo(a)pyrene (5-ring PAH, p = 7×10-7 Pa) for July 2013 with hourly output and 27 km horizontal grid spacing. The comparison of model predicted phenanthrene concentrations with measurements at a rural site near Beijing (own data, unpublished) validates the model's ability to simulate diurnal variations of gaseous PAHs. The model's performance is better in simulating day time than night time gaseous PAHs. The concentrations of PAHs had experienced significant diurnal variations in rural and remote areas of China. Elevated concentration levels of 40-60 ng m-3 for phenanthrene and 1-10 ng m-3 for benzo(a)pyrene are predicted in Shanxi, Guizhou, the North China Plain, the Sichuan Basin and Chongqing metropolitan areas due to the high emission densities at those locations. References [1] Keyte, I.J., Harrison, R.M., and Lammel, G., 2013: Chemical reactivity and long-range transport potential of polycyclic aromatic hydrocarbons - a review, Chem. Soc. Rev., 42, 9333-9391. [2] Grell, G.A, Peckham, S.E, Schmitz, R, McKeen, S.A, Frost, G, Skamarock, W.C, and Eder, B., 2005: Fully coupled online chemistry within the WRF model, Atmos. Environ., 39, 6957-6975. [3] Shen, H. Z., Huang, Y., Wang, R., Zhu, D., Li, W., Shen, G. F., Wang, B., Zhang, Y. Y., Chen, Y. C., Lu, Y., Chen, H., Li, T. C., Sun, K., Li, B. G., Liu, W. X., Liu, J. F., and Tao, S., 2013: Global atmospheric emissions of polycyclic aromatic hydrocarbons from 1960 to 2008 and future predictions, Environ. Sci. Technol., 47, 6415-6424.

Gasoline Vapor Recovery

NASA Technical Reports Server (NTRS)

1979-01-01

Gasoline is volatile and some of it evaporates during storage, giving off hydrocarbon vapor. Formerly, the vapor was vented into the atmosphere but anti-pollution regulations have precluded that practice in many localities, so oil companies and storage terminals are installing systems to recover hydrocarbon vapor. Recovery provides an energy conservation bonus in that most of the vapor can be reconverted to gasoline. Two such recovery systems are shown in the accompanying photographs (mid-photo at right and in the foreground below). They are actually two models of the same system, although.configured differently because they are customized to users' needs. They were developed and are being manufactured by Edwards Engineering Corporation, Pompton Plains, New Jersey. NASA technological information proved useful in development of the equipment.

Hydrodeoxygenation of the angelica lactone dimer, a cellulose-based feedstock: simple, high-yield synthesis of branched C7 -C10 gasoline-like hydrocarbons.

PubMed

Mascal, Mark; Dutta, Saikat; Gandarias, Inaki

2014-02-10

Dehydration of biomass-derived levulinic acid under solid acid catalysis and treatment of the resulting angelica lactone with catalytic K2 CO3 produces the angelica lactone dimer in excellent yield. This dimer serves as a novel feedstock for hydrodeoxygenation, which proceeds under relatively mild conditions with a combination of oxophilic metal and noble metal catalysts to yield branched C7 -C10 hydrocarbons in the gasoline volatility range. Considering that levulinic acid is available in >80 % conversion from raw biomass, a field-to-tank yield of drop-in, cellulosic gasoline of >60 % is possible. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of thiaarenes and polycyclic aromatic hydrocarbons in workplace air of an aluminum reduction plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becker, G.; Colmsjoe, A.; Oestman, C.

1999-05-01

Quantitation of a variety of tetra-, penta-, and hexacyclic aromatic sulfur heterocycles (thiaarenes) in workplace air of an aluminum reduction plant has been made by help of gas chromatography with atomic emission detection (GC-AED). Personal exposure to those thiaarenes and to polycyclic aromatic hydrocarbons depending on work categories has been evaluated. Summarized concentrations of the thiaarenes investigated have been found to be 0.4--19.0 {micro}g/m{sup 3}. When using sulfur selective AED, samples could be analyzed without a prior separation of the thiaarenes from the PAH. The present data indicate a contribution of thiaarenes to the overall toxicity of coal tar pitchmore » volatiles in this work environment.« less

In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

DOEpatents

Taylor, Robert T.; Jackson, Kenneth J.; Duba, Alfred G.; Chen, Ching-I

1998-01-01

An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating.

In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

DOEpatents

Taylor, R.T.; Jackson, K.J.; Duba, A.G.; Chen, C.I.

1998-05-19

An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs.

Proteomic and metabolomic analyses provide insight into production of volatile and non-volatile flavor components in mandarin hybrid fruit.

PubMed

Yu, Qibin; Plotto, Anne; Baldwin, Elizabeth A; Bai, Jinhe; Huang, Ming; Yu, Yuan; Dhaliwal, Harvinder S; Gmitter, Frederick G

2015-03-06

Although many of the volatile constituents of flavor and aroma in citrus have been identified, the knowledge of molecular mechanisms and regulation of volatile production are very limited. Our aim was to understand mechanisms of flavor volatile production and regulation in mandarin fruit. Fruits of two mandarin hybrids, Temple and Murcott with contrasting volatile and non- volatile profiles, were collected at three developmental stages. A combination of methods, including the isobaric tags for relative and absolute quantification (iTRAQ), quantitative real-time polymerase chain reaction, gas chromatography, and high-performance liquid chromatography, was used to identify proteins, measure gene expression levels, volatiles, sugars, organic acids and carotenoids. Two thirds of differentially expressed proteins were identified in the pathways of glycolysis, citric acid cycle, amino acid, sugar and starch metabolism. An enzyme encoding valencene synthase gene (Cstps1) was more abundant in Temple than in Murcott. Valencene accounted for 9.4% of total volatile content in Temple, whereas no valencene was detected in Murcott fruit. Murcott expression of Cstps1 is severely reduced. We showed that the diversion of valencene and other sesquiterpenes into the terpenoid pathway together with high production of apocarotenoid volatiles might have resulted in the lower concentration of carotenoids in Temple fruit.

Volatile organic compound emissions from engineered wood products

Treesearch

Steve Zylkowski; Charles Frihart

2017-01-01

Thirteen bonded engineered wood products representing those commonly used in building construction were evaluated for volatile organic chemicals using methods developed for interior bonded wood products. Although formaldehyde and acetaldehyde were emitted from all samples, they were not the dominant volatiles, which greatly depended on wood species and bonding...

'Scarlett Spur Red Delicious' apple volatile production accompanying physiological disorder development during low pO2 controlled atmosphere storage

USDA-ARS?s Scientific Manuscript database

Apple (Malus domestica Borkh.) fruit volatile production is regulated by a variety of factors including storage conditions. Although controlled atmosphere (CA) technology extends apple fruit storage life, improper storage conditions can adversely affect volatile production and increase the risk of ...

27 CFR 24.184 - Use of volatile fruit-flavor concentrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL WINE Production of Wine § 24.184 Use of volatile... production there may be added volatile fruit-flavor concentrate produced from the same kind of fruit or from the same variety of berry or grape so long as the proportion of volatile fruit-flavor concentrate...

27 CFR 24.184 - Use of volatile fruit-flavor concentrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Wine § 24.184 Use of volatile... production there may be added volatile fruit-flavor concentrate produced from the same kind of fruit or from the same variety of berry or grape so long as the proportion of volatile fruit-flavor concentrate...

27 CFR 24.184 - Use of volatile fruit-flavor concentrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Wine § 24.184 Use of volatile... production there may be added volatile fruit-flavor concentrate produced from the same kind of fruit or from the same variety of berry or grape so long as the proportion of volatile fruit-flavor concentrate...

27 CFR 24.184 - Use of volatile fruit-flavor concentrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Wine § 24.184 Use of volatile... production there may be added volatile fruit-flavor concentrate produced from the same kind of fruit or from the same variety of berry or grape so long as the proportion of volatile fruit-flavor concentrate...

27 CFR 24.184 - Use of volatile fruit-flavor concentrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL WINE Production of Wine § 24.184 Use of volatile... production there may be added volatile fruit-flavor concentrate produced from the same kind of fruit or from the same variety of berry or grape so long as the proportion of volatile fruit-flavor concentrate...

Interlake production established using quantitative hydrocarbon well-log analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lancaster, J.; Atkinson, A.

1988-07-01

Production was established in a new pay zone of the basal Interlake Formation adjacent to production in Midway field in Williams County, North Dakota. Hydrocarbon saturation, which was computed using hydrocarbon well-log (mud-log) data, and computed permeability encouraged the operator to run casing and test this zone. By use of drilling rig parameters, drilling mud properties, hydrocarbon-show data from the mud log, drilled rock and porosity descriptions, and wireline log porosity, this new technique computes oil saturation (percent of porosity) and permeability to the invading filtrate, using the Darcy equation. The Leonardo Fee well was drilled to test the Devonianmore » Duperow, the Silurian upper Interlake, and the Ordovician Red River. The upper two objectives were penetrated downdip from Midway production and there were no hydrocarbon shows. It was determined that the Red River was tight, based on sample examination by well site personnel. The basal Interlake, however, liberated hydrocarbon shows that were analyzed by this new technology. The results of this evaluation accurately predicted this well would be a commercial success when placed in production. Where geophysical log analysis might be questionable, this new evaluation technique may provide answers to anticipated oil saturation and producibility. The encouraging results of hydrocarbon saturation and permeability, produced by this technique, may be largely responsible for the well being in production today.« less

Optofluidic reactors for reverse combustion photocatalytic production of hydrocarbons (Conference Presentation)

NASA Astrophysics Data System (ADS)

Schein, Perry; Erickson, David

2017-03-01

In combustion, hydrocarbon fuels are burned with oxygen to release energy, carbon dioxide and water vapor. Here, we introduce a photocatalytic reactor for reversing this process, when carbon dioxide and water are combined and using optical and thermal energy from the sun hydrocarbons are produced and oxygen is released. This allows for the sustainable production of hydrocarbon products from non-fossil sources, allowing for the development of "green" hydrocarbon products. Our reactors take the form of modular cells of 10 x 10 x 10 cm scale where light is delivered to nanostructured catalysts through the evanescent field around dielectric slab waveguides. The light distribution is optimized through the use of engineered scattering sites to enhance field uniformity. This is combined with integrated fluidic architecture to deliver a stream rich in water and carbon dioxide (such as exhaust from a natural gas burning plant) to the nanostructured catalyst particles in a narrow channel. Exhaust streams rich in oxygen and hydrocarbon products are collected at the outlet of the reactor cell. The cell is heated using solar thermal energy and temperatures of up to 200°C are achieved, enhancing reaction efficiency. Hydrocarbon products produced include methanol as well as other potentially useful molecules for fuel production or precursors to the manufacture of plastics. These reactors can be coupled to solar collectors to take advantage of the sun as a free source of heat and light, and the modular nature of the cells enables scaling to larger deployments.

Characterization of Light Non-Methane Hydrocarbons, Surface Water DOC, and Aerosols over the Nordic Seas

NASA Astrophysics Data System (ADS)

Hudson, E. D.; Ariya, P. A.

2006-12-01

Whole air, size-fractionated marine aerosols, and surface ocean water DOC were sampled together during June-July 2004 on the Nordic seas, in order to explore factors leading to the formation of volatile organic compounds (VOCs) at the sea surface and their transfer to the atmosphere. High site-to-site variability in 19 non-methane hydrocarbon concentrations suggests highly variable, local sources for these compounds. Acetone, C5 and C6 hydrocarbons, and dimethylsulfide were identified in the seawater samples using solid-phase microextraction/GC-MS. The aerosols were analysed by SEM-EDX and contained primarily inorganic material (sea salt, marine sulfates, and carbonates) and little organic matter. However, a culturable bacterium was isolated from the large (9.9 - 18 μ m) fraction at one site, and identified as Micrococcus luteus. We will discuss the implication of these results on potential exchange processes at the ocean-atmosphere interface and the impact of bioaerosols in transferring marine organic carbon to atmospheric organic carbon.

Arctic springtime observations of volatile organic compounds during the OASIS-2009 campaign

NASA Astrophysics Data System (ADS)

Hornbrook, Rebecca S.; Hills, Alan J.; Riemer, Daniel D.; Abdelhamid, Aroob; Flocke, Frank M.; Hall, Samuel R.; Huey, L. Gregory; Knapp, David J.; Liao, Jin; Mauldin, Roy L.; Montzka, Denise D.; Orlando, John J.; Shepson, Paul B.; Sive, Barkley; Staebler, Ralf M.; Tanner, David. J.; Thompson, Chelsea R.; Turnipseed, Andrew; Ullmann, Kirk; Weinheimer, Andrew J.; Apel, Eric C.

2016-08-01

Gas-phase volatile organic compounds (VOCs) were measured at three vertical levels between 0.6 m and 5.4 m in the Arctic boundary layer in Barrow, Alaska, for the Ocean-Atmosphere-Sea Ice-Snowpack (OASIS)-2009 field campaign during March-April 2009. C4-C8 nonmethane hydrocarbons (NMHCs) and oxygenated VOCs (OVOCs), including alcohols, aldehydes, and ketones, were quantified multiple times per hour, day and night, during the campaign using in situ fast gas chromatography-mass spectrometry. Three canister samples were also collected daily and subsequently analyzed for C2-C5 NMHCs. The NMHCs and aldehydes demonstrated an overall decrease in mixing ratios during the experiment, whereas acetone and 2-butanone showed increases. Calculations of time-integrated concentrations of Br atoms, ∫[Br]dt, yielded values as high as (1.34 ± 0.27) × 1014 cm-3 s during the longest observed ozone depletion event (ODE) of the campaign and were correlated with the steady state Br calculated at the site during this time. Both chlorine and bromine chemistry contributed to the large perturbations on the production and losses of VOCs. Notably, acetaldehyde, propanal, and butanal mixing ratios dropped below the detection limit of the instrument (3 parts per trillion by volume (pptv) for acetaldehyde and propanal, 2 pptv for butanal) during several ODEs due to Br chemistry. Chemical flux calculations of OVOC production and loss are consistent with localized high Cl-atom concentrations either regionally or within a very shallow surface layer, while the deeper Arctic boundary layer provides a continuous source of precursor alkanes to maintain the OVOC mixing ratios.

[Analysis of aromatic hydrocarbons in cracking products of jet fuel by comprehensive two-dimensional gas chromatography-mass spectrometry].

PubMed

Li, Haijing; Zhang, Xiangwen

2017-08-08

As coking precursors, aromatic hydrocarbons have an effect on the cracking stability of fuels. A method for identifying and quantitating aromatics in the supercritical cracking products of jet fuel was established by comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC-MS). The effects of main chromatographic conditions such as initial oven temperature and modulation period on the separation of supercritical cracking products were studied. The method has good separation ability for polycyclic aromatic hydrocarbons (PAH) isomers. A total of 27 aromatics, including monocyclic aromatic hydrocarbons, bicyclic aromatic hydrocarbons, tricyclic aromatic hydrocarbons, tetracyclic aromatic hydrocarbons, etc., were identified based on standard mass spectra, the retention times of standards and literature reports. Moreover, the corresponding quantitative determination was achieved by external standard method of GC×GC-FID. The results showed that the contents of aromatics increased with the increase of gas yield. When gas yield reached 22%, the bicyclic aromatic hydrocarbons began to produce, and their contents increased exponentially with the increase of gas yield. Compared with the traditional GC-MS, the method has better separation and qualitative ability, and can be applied to the separation of complex samples and qualitative and quantitative analyses of cracking products.

Catalytic co-pyrolysis of waste vegetable oil and high density polyethylene for hydrocarbon fuel production.

PubMed

Wang, Yunpu; Dai, Leilei; Fan, Liangliang; Cao, Leipeng; Zhou, Yue; Zhao, Yunfeng; Liu, Yuhuan; Ruan, Roger

2017-03-01

In this study, a ZrO 2 -based polycrystalline ceramic foam catalyst was prepared and used in catalytic co-pyrolysis of waste vegetable oil and high density polyethylene (HDPE) for hydrocarbon fuel production. The effects of pyrolysis temperature, catalyst dosage, and HDPE to waste vegetable oil ratio on the product distribution and hydrocarbon fuel composition were examined. Experimental results indicate that the maximum hydrocarbon fuel yield of 63.1wt. % was obtained at 430°C, and the oxygenates were rarely detected in the hydrocarbon fuel. The hydrocarbon fuel yield increased when the catalyst was used. At the catalyst dosage of 15wt.%, the proportion of alkanes in the hydrocarbon fuel reached 97.85wt.%, which greatly simplified the fuel composition and improved the fuel quality. With the augment of HDPE to waste vegetable oil ratio, the hydrocarbon fuel yield monotonously increased. At the HDPE to waste vegetable oil ratio of 1:1, the maximum proportion (97.85wt.%) of alkanes was obtained. Moreover, the properties of hydrocarbon fuel were superior to biodiesel and 0 # diesel due to higher calorific value, better low-temperature low fluidity, and lower density and viscosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Carbon Isotopic Composition of CO2, Evolved During Perchlorate-Induced Reactions in Mars Analog Materials: Interpreting SAM/MSL Rocknest Data

NASA Technical Reports Server (NTRS)

Stern, J. C.; McAdam, A. C.; Archer, P. D., Jr.; Bower, H.; Buch, A.; Eigenbrode, J.; Freissinet, C.; Franz, H. B.; Glavin, D.; Jones, J. H.;

Thermal treatment of electronic waste in a fluidised bed and chemical digestion of solid products.

PubMed

Woynarowska, Amelia; Żukowski, Witold; Żelazny, Sylwester

2016-07-01

The article presents the results of e-waste thermal treatment in a fluidised bed reactor and solid products digestion under acidic conditions. During the processes, measurements of carbon monoxide, carbon dioxide, volatile organic compounds, nitrogen oxides, sulphur dioxide, hydrogen chloride, hydrogen bromide, hydrogen cyanide, ammonia, phenol, aliphatic and aromatic hydrocarbons, hydrogen fluoride and phosgene were carried out. Several digestion tests of the solid residue in sulphuric acid (VI) at 25 °C-65 °C, for 55 min-24 h were conducted. In each case, the dilution method was used, i.e. preliminary digestion in concentrated sulphuric acid (VI) (95%) for 40 min, and then dilution to expected concentrations (30%-50%). Most preferred results were obtained using sulphuric acid (VI) with a target concentration of 40% at 65 °C, where the leaching degrees were 76.56% for copper, 71.67% for iron, 91.89% for zinc and 97.40% for tin. The time necessary to effectively carry out the digestion process was 220 min. © The Author(s) 2016.

Modification of primordial ices by cosmic rays as simulated by cyclotron irradiation

NASA Technical Reports Server (NTRS)

Kaiser, R. I.; Roessler, K.

1992-01-01

Frozen CH4 and CH4/Ar mixtures closed into metal cuvettes and open to the vacuum were irradiated at 15 and 77 K with 10 - 20 MeV p and He-3(2+) ions in order to simulate the effect of cosmic rays on solid organic matter in space. Ices exposed to vacuum represent surfaces of icy systems whereas closed systems stand for bulk ices. The products were analyzed by MS, SEM, RBS, ERDA, H-1-NMR, HPLC, GC-MS, NEXAFS, and FT-IR. Volatile products consisted of a mixture of low molecular species, e.g., C2H2, C2H4, C2H6, and long linear aliphatic and olefinic compounds. The formation of polycyclic aromatic hydrocarbons (PAH's) and related species in solid CH4 is due to a multi-center reaction within one collision cascade and is governed by energy density effects with critical linear energy transfer values L(sub T) between 2 and 10 keV/micron. Open ices exhibit preferential hydrogen release resulting in an increased carbonization as compared to more hydrogen rich molecules protected inside large icy bodies.

Quantity and quality of stormwater collected from selected stormwater outfalls at industrial sites, Fort Gordon, Georgia, 2012

USGS Publications Warehouse

Nagle, Doug D.

2013-01-01

Samples from sites SWR11–3, SWR11–4, and SWR11–5 were analyzed for 83 volatile and semivolatile organic compounds. Eight polycyclic aromatic hydrocarbon compounds, benzo[a]pyrene, benzo[b]fluoranthene, benzo[ghi]perylene, benzo[k]fluoranthene, chrysene, indeno[1,2,3-cd]pyrene, phenanthrene, and pyrene, were detected at all three sites. Of the 86 volatile and semivolatile organic compounds that were analyzed in stormwater samples from heating and cooling sites, 15 (18 percent) were detected at site SWR11–3, 12 (14 percent) were detected at site SWR11–4, and 17 (20 percent) were detected at site SWR11–5.

Nitrification and Autotrophic Nitrifying Bacteria in a Hydrocarbon-Polluted Soil

PubMed Central

Deni, Jamal; Penninckx, Michel J.

1999-01-01

In vitro ammonia-oxidizing bacteria are capable of oxidizing hydrocarbons incompletely. This transformation is accompanied by competitive inhibition of ammonia monooxygenase, the first key enzyme in nitrification. The effect of hydrocarbon pollution on soil nitrification was examined in situ. In a microcosm study, adding diesel fuel hydrocarbon to an uncontaminated soil (agricultural unfertilized soil) treated with ammonium sulfate dramatically reduced the amount of KCl-extractable nitrate but stimulated ammonium consumption. In a soil with long history of pollution that was treated with ammonium sulfate, 90% of the ammonium was transformed into nitrate after 3 weeks of incubation. Nitrate production was twofold higher in the contaminated soil than in the agricultural soil to which hydrocarbon was not added. To assess if ammonia-oxidizing bacteria acquired resistance to inhibition by hydrocarbon, the contaminated soil was reexposed to diesel fuel. Ammonium consumption was not affected, but nitrate production was 30% lower than nitrate production in the absence of hydrocarbon. The apparent reduction in nitrification resulted from immobilization of ammonium by hydrocarbon-stimulated microbial activity. These results indicated that the hydrocarbon inhibited nitrification in the noncontaminated soil (agricultural soil) and that ammonia-oxidizing bacteria in the polluted soil acquired resistance to inhibition by the hydrocarbon, possibly by increasing the affinity of nitrifying bacteria for ammonium in the soil. PMID:10473409

Volatile profile, lipid oxidation and protein oxidation of irradiated ready-to-eat cured turkey meat products

NASA Astrophysics Data System (ADS)

Feng, Xi; Ahn, Dong Uk

2016-10-01

Irradiation had little effects on the thiobarbituric acid reactive substances (TBARS) values in ready-to-eat (RTE) turkey meat products, while it increased protein oxidation at 4.5 kGy. The volatile profile analyses indicated that the amount of sulfur compounds increased linearly as doses increased in RTE turkey meat products. By correlation analysis, a positive correlation was found between benzene/ benzene derivatives and alcohols with lipid oxidation, while aldehydes, ketones and alkane, alkenes and alkynes were positively correlated with protein oxidation. Principle component analysis showed that irradiated meat samples can be discriminated by two categories of volatile compounds: Strecker degradation products and radiolytic degradation products. The cluster analysis of volatile data demonstrated that low-dose irradiation had minor effects on the volatile profile of turkey sausages (<1.5 kGy). However, as the doses increased, the differences between the irradiated and non-irradiated cured turkey products became significant.

Discrete fracture modeling of multiphase flow and hydrocarbon production in fractured shale or low permeability reservoirs

NASA Astrophysics Data System (ADS)

Hao, Y.; Settgast, R. R.; Fu, P.; Tompson, A. F. B.; Morris, J.; Ryerson, F. J.

2016-12-01

It has long been recognized that multiphase flow and transport in fractured porous media is very important for various subsurface applications. Hydrocarbon fluid flow and production from hydraulically fractured shale reservoirs is an important and complicated example of multiphase flow in fractured formations. The combination of horizontal drilling and hydraulic fracturing is able to create extensive fracture networks in low permeability shale rocks, leading to increased formation permeability and enhanced hydrocarbon production. However, unconventional wells experience a much faster production decline than conventional hydrocarbon recovery. Maintaining sustainable and economically viable shale gas/oil production requires additional wells and re-fracturing. Excessive fracturing fluid loss during hydraulic fracturing operations may also drive up operation costs and raise potential environmental concerns. Understanding and modeling processes that contribute to decreasing productivity and fracturing fluid loss represent a critical component for unconventional hydrocarbon recovery analysis. Towards this effort we develop a discrete fracture model (DFM) in GEOS (LLNL multi-physics computational code) to simulate multiphase flow and transfer in hydraulically fractured reservoirs. The DFM model is able to explicitly account for both individual fractures and their surrounding rocks, therefore allowing for an accurate prediction of impacts of fracture-matrix interactions on hydrocarbon production. We apply the DFM model to simulate three-phase (water, oil, and gas) flow behaviors in fractured shale rocks as a result of different hydraulic stimulation scenarios. Numerical results show that multiphase flow behaviors at the fracture-matrix interface play a major role in controlling both hydrocarbon production and fracturing fluid recovery rates. The DFM model developed in this study will be coupled with the existing hydro-fracture model to provide a fully integrated geomechanical and reservoir simulation capability for an accurate prediction and assessment of hydrocarbon production and hydraulic fracturing performance. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Ethane in Planetary and Cometary Atmospheres: Transmittance and Fluorescence Models of the nu7 Band at 3.3 Micrometers

NASA Technical Reports Server (NTRS)

Villanueva, G. L.; Mumma, M. J.; Magee-Sauer, K.

2011-01-01

Ethane and other hydrocarbon gases have strong rovibrational transitions in the 3.3 micron spectral region owing to C-H, CH2, and CH3 vibrational modes, making this spectral region prime for searching possible biomarker gases in extraterrestrial atmospheres (e.g., Mars, exoplanets) and organic molecules in comets. However, removing ethane spectral signatures from high-resolution terrestrial transmittance spectra has been imperfect because existing quantum mechanical models have been unable to reproduce the observed spectra with sufficient accuracy. To redress this problem, we constructed a line-by-line model for the n7 band of ethane (C2H6) and applied it to compute telluric transmittances and cometary fluorescence efficiencies. Our model considers accurate spectral parameters, vibration-rotation interactions, and a functional characterization of the torsional hot band. We integrated the new band model into an advanced radiative transfer code for synthesizing the terrestrial atmosphere (LBLRTM), achieving excellent agreement with transmittance data recorded against Mars using three different instruments located in the Northern and Southern hemispheres. The retrieved ethane abundances demonstrate the strong hemispheric asymmetry noted in prior surveys of volatile hydrocarbons. We also retrieved sensitive limits for the abundance of ethane on Mars. The most critical validation of the model was obtained by comparing simulations of C2H6 fluorescent emission with spectra of three hydrocarbon-rich comets: C/2004 Q2 (Machholz), 8P/Tuttle, and C/2007 W1 (Boattini). The new model accurately describes the complex emission morphology of the nu7 band at low rotational temperatures and greatly increases the confidence of the retrieved production rates (and rotational temperatures) with respect to previously available fluorescence models.

EOBII, a Gene Encoding a Flower-Specific Regulator of Phenylpropanoid Volatiles' Biosynthesis in Petunia[C][W

PubMed Central

Spitzer-Rimon, Ben; Marhevka, Elena; Barkai, Oren; Marton, Ira; Edelbaum, Orit; Masci, Tania; Prathapani, Naveen-Kumar; Shklarman, Elena; Ovadis, Marianna; Vainstein, Alexander

2010-01-01

Floral scent, which is determined by a complex mixture of low molecular weight volatile molecules, plays a major role in the plant's life cycle. Phenylpropanoid volatiles are the main determinants of floral scent in petunia (Petunia hybrida). A screen using virus-induced gene silencing for regulators of scent production in petunia flowers yielded a novel R2R3-MYB–like regulatory factor of phenylpropanoid volatile biosynthesis, EMISSION OF BENZENOIDS II (EOBII). This factor was localized to the nucleus and its expression was found to be flower specific and temporally and spatially associated with scent production/emission. Suppression of EOBII expression led to significant reduction in the levels of volatiles accumulating in and emitted by flowers, such as benzaldehyde, phenylethyl alcohol, benzylbenzoate, and isoeugenol. Up/downregulation of EOBII affected transcript levels of several biosynthetic floral scent-related genes encoding enzymes from the phenylpropanoid pathway that are directly involved in the production of these volatiles and enzymes from the shikimate pathway that determine substrate availability. Due to its coordinated wide-ranging effect on the production of floral volatiles, and its lack of effect on anthocyanin production, a central regulatory role is proposed for EOBII in the biosynthesis of phenylpropanoid volatiles. PMID:20543029

21 CFR 178.3530 - Isoparaffinic petroleum hydrocarbons, synthetic.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Isoparaffinic petroleum hydrocarbons, synthetic... hydrocarbons, synthetic. Isoparaffinic petroleum hydrocarbons, synthetic, may be safely used in the production... isoparaffinic petroleum hydrocarbons, produced by synthesis from petroleum gases consist of a mixture of liquid...

21 CFR 178.3530 - Isoparaffinic petroleum hydrocarbons, synthetic.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Isoparaffinic petroleum hydrocarbons, synthetic... hydrocarbons, synthetic. Isoparaffinic petroleum hydrocarbons, synthetic, may be safely used in the production... isoparaffinic petroleum hydrocarbons, produced by synthesis from petroleum gases consist of a mixture of liquid...

Biochemistry of Apple Aroma: A Review.

PubMed

Espino-Díaz, Miguel; Sepúlveda, David Roberto; González-Aguilar, Gustavo; Olivas, Guadalupe I

2016-12-01

Flavour is a key quality attribute of apples defined by volatile aroma compounds. Biosynthesis of aroma compounds involves metabolic pathways in which the main precursors are fatty and amino acids, and the main products are aldehydes, alcohols and esters. Some enzymes are crucial in the production of volatile compounds, such as lipoxygenase, alcohol dehydrogenase, and alcohol acyltransferase. Composition and concentration of volatiles in apples may be altered by pre- and postharvest factors that cause a decline in apple flavour. Addition of biosynthetic precursors of volatile compounds may be a strategy to promote aroma production in apples. The present manuscript compiles information regarding the biosynthesis of volatile aroma compounds, including metabolic pathways, enzymes and substrates involved, factors that may affect their production and also includes a wide number of studies focused on the addition of biosynthetic precursors in their production.

Biochemistry of Apple Aroma: A Review

PubMed Central

Espino-Díaz, Miguel; Sepúlveda, David Roberto; González-Aguilar, Gustavo

2016-01-01

Summary Flavour is a key quality attribute of apples defined by volatile aroma compounds. Biosynthesis of aroma compounds involves metabolic pathways in which the main precursors are fatty and amino acids, and the main products are aldehydes, alcohols and esters. Some enzymes are crucial in the production of volatile compounds, such as lipoxygenase, alcohol dehydrogenase, and alcohol acyltransferase. Composition and concentration of volatiles in apples may be altered by pre- and postharvest factors that cause a decline in apple flavour. Addition of biosynthetic precursors of volatile compounds may be a strategy to promote aroma production in apples. The present manuscript compiles information regarding the biosynthesis of volatile aroma compounds, including metabolic pathways, enzymes and substrates involved, factors that may affect their production and also includes a wide number of studies focused on the addition of biosynthetic precursors in their production. PMID:28115895

Aerial Sampling of Emissions from Biomass Pile Burns in ...

EPA Pesticide Factsheets

Abstract (already cleared). Emissions from burning piles of post-harvest timber slash in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5 µm), black carbon, ultraviolet absorbing PM, elemental/organic carbon, semi-volatile organics (polycyclic aromatic hydrocarbons and polychlorinated dibenzodioxins/dibenzofurans), filter-based metals, and volatile organics were sampled for determination of emission factors. The effect on emissions from covering or not covering piles with polyethylene sheets to prevent fuel wetting was determined. Results showed that the uncovered (“wet”) piles burned with lower combustion efficiency and higher emissions of volatile organic compounds. Results for other pollutants will also be discussed. This work determines the first known in-field emission factors for burning of timber slash piles. The results also document the effect on emissions of covering the piles with polyethylene covers to reduce the moisture content of the biomass.

Halogenated hydrocarbon pesticides and other volatile organic contaminants provide analytical challenges in global trading.

PubMed

Budnik, Lygia T; Fahrenholtz, Svea; Kloth, Stefan; Baur, Xaver

2010-04-01

Protection against infestation of a container cargo by alien species is achieved by mandatory fumigation with pesticides. Most of the effective fumigants are methyl and ethyl halide gases that are highly toxic and are a risk to both human health and the environment. There is a worldwide need for a reliable and robust analytical screening procedure for these volatile chemicals in a multitude of health and environmental scenarios. We have established a highly sensitive broad spectrum mass spectrometry method combined with thermal desorption gas chromatography to detect, identify and quantify volatile pesticide residues. Using this method, 1201 random ambient air samples taken from freight containers arriving at the biggest European ports of Hamburg and Rotterdam were analyzed over a period of two and a half years. This analytical procedure is a valuable strategy to measure air pollution from these hazardous chemicals, to help in the identification of pesticides in the new mixtures/formulations that are being adopted globally and to analyze expired breath samples after suspected intoxication in biomonitoring.

Essential oil composition of stems and fruits of Caralluma europaea N.E.Br. (Apocynaceae).

PubMed

Zito, Pietro; Sajeva, Maurizio; Bruno, Maurizio; Maggio, Antonella; Rosselli, Sergio; Formisano, Carmen; Senatore, Felice

2010-01-27

The essential oil of the stems and fruits of Caralluma europaea (Guss.) N.E.Br. (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analyzed. The analyses allowed the identification and quantification of 74 volatile compounds, of which 16 were aromatic and 58 non-aromatic. Stems and fruits contained 1.4% and 2.7% of aromatic compounds respectively, while non-aromatic were 88.3% and 88.8%. Non-aromatic hydrocarbons were the most abundant compounds in both organs, followed by fatty acids. Data showed differences in the profiles between stems and fruits which shared only eighteen compounds; stems accounted for 38 compounds while fruits for 53. Fruits showed a higher diversity especially in aromatic compounds with twelve versus four in stems. Among the volatiles identified in stems and fruits of C. europaea 26 are present in other taxa of Apocynaceae, 52 are semiochemicals for many insects, and 21 have antimicrobial activity. The possible ecological role of the volatiles found is briefly discussed.

IRIS Toxicological Review and Summary Documents for ...

EPA Pesticide Factsheets

Carbon tetrachloride is a volatile haloalkane with a wide range of industrial and chemical applications. It is produced commercially from chlorination of a variety of low molecular weight hydrocarbons such as carbon disulfide, methanol, methane, propane, and ethylene dichloride. It is also produced by thermal chlorination in the production of tetrachloroethylene. Major uses of carbon tetrachloride have been in the recovery of tin from tin plating waste, in formulation of petrol additives and refrigerants, in metal degreasing and agricultural fumigants, in chlorination of organic compounds, in the production of semiconductors, in the reduction of fire hazard, as a solvent for rubber cement, and as a catalyst in polymer technology. Its production has been decreasing and it is no longer permitted in products intended for home use. Despite this ban, carbon tetrachloride has been detected at 314 hazardous waste sites. EPA's assessment of noncancer health effects and carcinogenic potential of carbon tetrachloride was last prepared and added to the IRIS database in 1991. The IRIS program is preparing an assessment that will incorporate health effects information available for carbon tetrachloride, and current risk assessment methods. The IRIS assessment for carbon tetrachloride will consist of a Toxicological Review and IRIS Summary. The Toxicological Review is a critical review of the physiochemical and toxicokinetic properties of a chemical, and its toxicity

Low-cost process for hydrogen production

DOEpatents

Cha, Chang Y.; Bauer, Hans F.; Grimes, Robert W.

1993-01-01

A method is provided for producing hydrogen and carbon black from hydrocarbon gases comprising mixing the hydrocarbon gases with a source of carbon and applying radiofrequency energy to the mixture. The hydrocarbon gases and the carbon can both be the products of gasification of coal, particularly the mild gasification of coal. A method is also provided for producing hydrogen an carbon monoxide by treating a mixture of hydrocarbon gases and steam with radio-frequency energy.

Low-cost process for hydrogen production

DOEpatents

Cha, C.H.; Bauer, H.F.; Grimes, R.W.

1993-03-30

A method is provided for producing hydrogen and carbon black from hydrocarbon gases comprising mixing the hydrocarbon gases with a source of carbon and applying radiofrequency energy to the mixture. The hydrocarbon gases and the carbon can both be the products of gasification of coal, particularly the mild gasification of coal. A method is also provided for producing hydrogen and carbon monoxide by treating a mixture of hydrocarbon gases and steam with radio-frequency energy.

Emission of Volatile OrganoHalogens by Southern African Solar Salt Works

NASA Astrophysics Data System (ADS)

Kotte, Karsten; Weissflog, Ludwig; Lange, Christian Albert; Huber, Stefan; Pienaar, Jacobus J.

2010-05-01

Volatile organic compounds containing halogens - especially chlorine - have been considered for a long time of industrial origin only, and it was assumed that the production and emission of these compounds can easily be controlled by humans in case they will cause a threat for life on Earth. Since the middle of the 80ies of the last century it became clear that the biologically active organohalogens isolated by chemists are purposefully produced by nature as antibiotics or as antifeedant etc. To date more than 3800 organohalogens are known to be naturally produced by bio-geochemical processes. The global budgets of many such species are poorly understood and only now with the emergence of better analytical techniques being discovered. For example the compound chloromethane nature's production (5 GT) outdates the anthropogenic production (50 KT) by a factor of 100. Thus organohalogens are an interesting recent case in point since they can influence the ozone budget of the boundary layer, play a role in the production of aerosols and the climate change discussion. An intriguing observation is that most of the atmospheric CH3Cl and CH3Br are of terrestrial rather than of marine origin and that a number of halogenated small organic molecules are produced in soils. The high concentrations of halides in salt soils point to a possibly higher importance of natural halogenation processes as a source of volatile organohalogens. Terrestrial biota, such as fungi, plants, animals and insects, as well as marine algea, bacteria and archaea are known or suspected to be de-novo producers of volatile organohalogens. In recent years we revealed the possibility for VOX to form actively in water and bottom sediments of hyper-saline environments in the course of studying aridization processes during climatic warming. Due to the nature of their production process solar salt works, as to be found along-side the Southern African coast line but also upcountry, combine a variety of semi- and hyper-saline environments, rich in chloride, bromide and partly iodide. They can be seen as semi natural reactors for hypersaline microorganisms like bacteria, algae and archaea as they can be found in natural hypersaline environments as well. To assess possible VOX emission of solar salt works the Walfishbay Salt Refiners (PTY) LTD (Namibia) were investigated and sediments of several crystallizer pans where collected. Only affected by natural temperature and radiation regime the VOX production inside the tightly closed incubation vials were determined regularly for several months by using headspace GC combined with an electron capture detector. Besides a number of non halogenated volatile hydrocarbons, detected by a self modified purge and trap GC/MS system the following VOX have been identified: CHCl3, CH3J, CH3Br, CCl4, C2HCl3, C2Cl4. According to earlier experiments on natural salt sediments of Southern Russia a biosynthesis process involving halophilic archaea is highly probable. Although the metabolic routes entailed are not yet identified. Obtained long term emission data are presented by focussing on possible meteorological propulsion as solar and UV radiation as well as temperature. Discussing the incubation experiments Southern African solar salt works reveal to represent interesting sources of chemically active VOX.

Effect of Substrate Character on Heterogeneous Ozone Reaction Rate with Individual PAHs and Their Reaction Mixtures

NASA Astrophysics Data System (ADS)

Holmen, B. A.; Stevens, T.

2009-12-01

Vehicle exhaust contains many unregulated chemical compounds that are harmful to human health and the natural environment, including polycyclic aromatic hydrocarbons (PAH), a class of organic compounds derived from fuel combustion that can be carcinogenic and mutagenic. PAHs have been quantified in vehicle-derived ultrafine particles (Dp<100nm), which are more toxic than larger particles and are linked to adverse health problems, including respiratory and cardiac disease. Once emitted into the atmosphere, particle-bound PAHs can undergo “aging” reactions with oxidants, such as ozone, to form more polar species. These polar reaction products include species such as quinones that can be more toxic than the parent PAH compounds. Here, 0.4ppm ozone was reacted over a 24-hour period with the 16 EPA priority PAHs plus coronene adsorbed to (i) a quartz fiber filter and (ii) NIST diesel PM. The difference in the PAH/O3 heterogeneous reaction rate resulting from the two substrates will be discussed. The experiments were completed by spiking a known PAH mixture to the solid, reacting the samples with gas-phase ozone, and determining both PAH loss over time and products formed, using thermal-desorption gas chromatography / mass spectrometry (TD-GC/MS). The individual PAHs anthracene, phenanthrene, and fluorene, adsorbed to a QFF were also separately reacted with 0.4 ppm ozone. A volatilization control and the collection of volatilized PAHs using a Tenax-packed thermal desorption vial completed the mass balance and aided determination parent-product relationships. Heterogeneous reaction products analyzed directly without derivatization indicate the formation of 9,10-anthracenedione, 9H-fluoren-9-one, and (1,1’-biphenyl)-2,2’-dicarboxaldehyde from the reaction of ozone with the PAH mix on a QFF, but only 9,10-anthracenedione was detected for the diesel PM reaction. The implications of these results for aging of diesel particulate in urban environments will be discussed.

Risk Modelling of Agricultural Products

NASA Astrophysics Data System (ADS)

Nugrahani, E. H.

2017-03-01

In the real world market, agricultural commodity are imposed with fluctuating prices. This means that the price of agricultural products are relatively volatile, which means that agricultural business is a quite risky business for farmers. This paper presents some mathematical models to model such risks in the form of its volatility, based on certain assumptions. The proposed models are time varying volatility model, as well as time varying volatility with mean reversion and with seasonal mean equation models. Implementation on empirical data show that agricultural products are indeed risky.

Modelling of Seismic and Resistivity Responses during the Injection of CO2 in Sandstone Reservoir

NASA Astrophysics Data System (ADS)

Omar, Muhamad Nizarul Idhafi Bin; Almanna Lubis, Luluan; Nur Arif Zanuri, Muhammad; Ghosh, Deva P.; Irawan, Sonny; Regassa Jufar, Shiferaw

2016-07-01

Enhanced oil recovery plays vital role in production phase in a producing oil field. Initially, in many cases hydrocarbon will naturally flow to the well as respect to the reservoir pressure. But over time, hydrocarbon flow to the well will decrease as the pressure decrease and require recovery method so called enhanced oil recovery (EOR) to recover the hydrocarbon flow. Generally, EOR works by injecting substances, such as carbon dioxide (CO2) to form a pressure difference to establish a constant productive flow of hydrocarbon to production well. Monitoring CO2 performance is crucial in ensuring the right trajectory and pressure differences are established to make sure the technique works in recovering hydrocarbon flow. In this paper, we work on computer simulation method in monitoring CO2 performance by seismic and resistivity model, enabling geoscientists and reservoir engineers to monitor production behaviour as respect to CO2 injection.

Report for Full-Scale Mulch Wall Treatment of Chlorinated Hydrocarbon-Impacted Groundwater

DTIC Science & Technology

2004-04-13

7.1 Direction of Groundwater Flow Through the Test Area Static water level measurements were taken every quarter after the installation of the...volatile organic compounds, alternate electron acceptors/byproducts and water quality parameters. Potentiometric surface maps showed the groundwater ... groundwater and surface water restrictions 10 Established clear zone (3000 ft by 3000 ft) Building 301 CEA Previously installed soil boring MW-19I 19

242-A Evaporator/plutonium uranium extraction (PUREX) effluent treatment facility (ETF) nonradioactive air emission test report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, J.S., Westinghouse Hanford

1996-05-10

This report shows the methods used to test the stack gas outlet concentration and emission rate of Volatile Organic Compounds as Total Non-Methane Hydrocarbons in parts per million by volume,grams per dry standard cubic meter, and grams per minute from the PUREX ETF stream number G6 on the Hanford Site. Test results are shown in Appendix B.1.

Volatile and semivolatile organic compounds in laboratory ...

EPA Pesticide Factsheets

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

Organic contamination of ground water at Gas Works Park, Seattle, Washington

USGS Publications Warehouse

Turney, G.L.; Goerlitz, D.F.

1990-01-01

Gas Works Park, in Seattle, Washington, is located on the site of a coal and oil gasification plant that ceased operation in 1956. During operation, many types of wastes, including coal, tar, and oil, accumulated on-site. The park soil is currently (1986) contaminated with compounds such as polynuclear aromatic hydrocarbons, volatile organic compounds, trace metals, and cyanide. Analyses of water samples from a network of observation wells in the park indicate that these compounds are also present in the ground water. Polynuclear aromatic hydrocarbons and volatile organic compounds were identified in ground water samples in concentrations as large as 200 mg/L. Concentrations of organic compounds were largest where ground water was in contact with a non-aqueous phase liquid in the soil. Where no non-aqueous phase liquid was present, concentrations were much smaller, even if the ground water was in contact with contaminated soils. This condition is attributed to weathering processes in which soluble, low-molecular-weight organic compounds are preferentially dissolved from the non-aqueous phase liquid into the ground water. Where no non-aqueous phase liquid is present, only stained soils containing relatively insoluble, high-molecular-weight compounds remain. Concentrations of organic contaminants in the soils may still remain large.

A new sensor for the assessment of personal exposure to volatile organic compounds

NASA Astrophysics Data System (ADS)

Chen, Cheng; Driggs Campbell, Katherine; Negi, Indira; Iglesias, Rodrigo A.; Owens, Patrick; Tao, Nongjian; Tsow, Francis; Forzani, Erica S.

2012-07-01

To improve our understanding of indoor and outdoor personal exposures to common environmental toxicants released into the environment, new technologies that can monitor and quantify the toxicants anytime anywhere are needed. This paper presents a wearable sensor to provide such capabilities. The sensor can communicate with a common smart phone and provides accurate measurement of volatile organic compound concentration at a personal level in real-time, providing environmental toxicants data every three minutes. The sensor has high specificity and sensitivity to aromatic, alkyl, and chlorinated hydrocarbons with a resolution as low as 4 parts-per-billion (ppb), with a detection range of 4 ppb-1000 ppm (parts-per-million). The sensor's performance was validated using Gas Chromatography and Selected Ion Flow Tube - Mass Spectrometry reference methods in a variety of environments and activities with overall accuracy higher than 81% (r2 > 0.9). Field tests examined personal exposure in various scenarios including: indoor and outdoor environments, traffic exposure in different cities which vary from 0 to 50 ppmC (part-per-million carbon from hydrocarbons), and pollutants near the 2010 Deepwater Horizon's oil spill. These field tests not only validated the performance but also demonstrated unprecedented high temporal and spatial toxicant information provided by the new technology.

Polycyclic Aromatic Hydrocarbon (PAH) and Oxygenated PAH (OPAH) Air–Water Exchange during the Deepwater Horizon Oil Spill

PubMed Central

2015-01-01

Passive sampling devices were used to measure air vapor and water dissolved phase concentrations of 33 polycyclic aromatic hydrocarbons (PAHs) and 22 oxygenated PAHs (OPAHs) at four Gulf of Mexico coastal sites prior to, during, and after shoreline oiling from the Deepwater Horizon oil spill (DWH). Measurements were taken at each site over a 13 month period, and flux across the water–air boundary was determined. This is the first report of vapor phase and flux of both PAHs and OPAHs during the DWH. Vapor phase sum PAH and OPAH concentrations ranged between 1 and 24 ng/m3 and 0.3 and 27 ng/m3, respectively. PAH and OPAH concentrations in air exhibited different spatial and temporal trends than in water, and air–water flux of 13 individual PAHs were strongly associated with the DWH incident. The largest PAH volatilizations occurred at the sites in Alabama and Mississippi in the summer, each nominally 10 000 ng/m2/day. Acenaphthene was the PAH with the highest observed volatilization rate of 6800 ng/m2/day in September 2010. This work represents additional evidence of the DWH incident contributing to air contamination, and provides one of the first quantitative air–water chemical flux determinations with passive sampling technology. PMID:25412353

Essential Oil Composition and Volatile Profile of Seven Helichrysum Species Grown in Italy.

PubMed

Giovanelli, Silvia; De Leo, Marinella; Cervelli, Claudio; Ruffoni, Barbara; Ciccarelli, Daniela; Pistelli, Luisa

2018-03-06

Helichrysum genus consists of about 600 species widespread throughout the world, especially in South Africa and in the Mediterranean area. In this study the aroma profile (HS-SPME) and the EO compositions of seven Helichrysum species (H. cymosum, H. odoratissimum, H. petiolare, H. fontanesii, H. saxatile, H. sanguineum, and H. tenax) were evaluated. All the plants were grown in Italy under the same growth conditions. The volatile constituents, particularly monoterpenes, depended by the plant's genotype and ecological adaptation. This study represents the first headspace evaluation on the selected plants and the results evidenced that monoterpenes represented the main class of constituents in five of the seven species analysed (from 59.2% to 95.0%). The higher content in sesquiterpene hydrocarbons was observed in the Mediterranean species of H. sanguineum (68.0%). Only H. saxatile showed relative similar abundance of monoterpenes and sesquiterpene hydrocarbons. The essential oil composition of the majority of examined species are characterised by high percentage of sesquiterpenes (especially β-caryophyllene and δ-cadinene) ranging from 51.3% to 92.0%, except for H. cymosum, H. tenax, and H. sanguineum leaves where monoterpenes predominated (from 51.7% to 74.7%). © 2018 Wiley-VHCA AG, Zurich, Switzerland.

A New Sensor for the Assessment of Personal Exposure to Volatile Organic Compounds

PubMed Central

Chen, Cheng; Campbell, Katherine Driggs; Negi, Indira; Iglesias, Rodrigo A.; Owens, Patrick; Tao, Nongjian; Tsow, Francis; Forzani, Erica

2012-01-01

To improve our understanding of indoor and outdoor personal exposures to common environmental toxicants released into the environment, new technologies that can monitor and quantify the toxicants anytime anywhere are needed. This paper presents a wearable sensor to provide such capabilities. The sensor can communicate with a common smart phone and provides accurate measurement of volatile organic compound concentration at a personal level in real time, providing environmental toxicants data every three minutes. The sensor has high specificity and sensitivity to aromatic, alkyl, and chlorinated hydrocarbons with a resolution as low as 4 parts per billion (ppb), with a detection range of 4 ppb to 1000 ppm (parts per million). The sensor's performance was validated using Gas Chromatography and Selected Ion Flow Tube - Mass Spectrometry reference methods in a variety of environments and activities with overall accuracy higher than 81% (r2 > 0.9). Field tests examined personal exposure in various scenarios including: indoor and outdoor environments, traffic exposure in different cities which vary from 0 to 50 ppmC (part-per-million carbon from hydrocarbons), and pollutants near the 2010 Deepwater Horizon's oil spill. These field tests not only validated the performance but also demonstrated unprecedented high temporal and spatial toxicant information provided by the new technology. PMID:22736952

Nucleation mode particles with a nonvolatile core in the exhaust of a heavy duty diesel vehicle.

PubMed

Rönkkö, Topi; Virtanen, Annele; Kannosto, Jonna; Keskinen, Jorma; Lappi, Maija; Pirjola, Liisa

2007-09-15

The characteristics of the nucleation mode particles of a Euro IV heavy-duty diesel vehicle exhaust were studied. The NOx and PM emissions of the vehicle were controlled through the use of cooled EGR and high-pressure fuel injection techniques; no exhaust gas after-treatment was used. Particle measurements were performed in vehicle laboratory and on road. Nucleation mode dominated the particle number size distribution in all the tested driving conditions. According to the on-road measurements, the nucleation mode was already formed after 0.7 s residence time in the atmosphere and no significant changes were observed for longer residence times. The nucleation mode was insensitive to the fuel sulfur content, dilution air temperature, and relative humidity. An increase in the dilution ratio decreased the size of the nucleation mode particles. This behavior was observed to be linked to the total hydrocarbon concentration in the diluted sample. In volatility measurements, the nucleation mode particles were observed to have a nonvolatile core with volatile species condensed on it. The results indicate that the nucleation mode particles have a nonvolatile core formed before the dilution process. The core particles have grown because of the condensation of semivolatile material, mainly hydrocarbons, during the dilution.

Polycyclic aromatic hydrocarbon (PAH) and oxygenated PAH (OPAH) air-water exchange during the deepwater horizon oil spill.

PubMed

Tidwell, Lane G; Allan, Sarah E; O'Connell, Steven G; Hobbie, Kevin A; Smith, Brian W; Anderson, Kim A

2015-01-06

Passive sampling devices were used to measure air vapor and water dissolved phase concentrations of 33 polycyclic aromatic hydrocarbons (PAHs) and 22 oxygenated PAHs (OPAHs) at four Gulf of Mexico coastal sites prior to, during, and after shoreline oiling from the Deepwater Horizon oil spill (DWH). Measurements were taken at each site over a 13 month period, and flux across the water-air boundary was determined. This is the first report of vapor phase and flux of both PAHs and OPAHs during the DWH. Vapor phase sum PAH and OPAH concentrations ranged between 1 and 24 ng/m(3) and 0.3 and 27 ng/m(3), respectively. PAH and OPAH concentrations in air exhibited different spatial and temporal trends than in water, and air-water flux of 13 individual PAHs were strongly associated with the DWH incident. The largest PAH volatilizations occurred at the sites in Alabama and Mississippi in the summer, each nominally 10,000 ng/m(2)/day. Acenaphthene was the PAH with the highest observed volatilization rate of 6800 ng/m(2)/day in September 2010. This work represents additional evidence of the DWH incident contributing to air contamination, and provides one of the first quantitative air-water chemical flux determinations with passive sampling technology.

Monitoring the tobacco use epidemic II. The Agent: Current and Emerging Tobacco Products

PubMed Central

Stellman, Steven D.; Djordjevic, Mirjana V.

2009-01-01

Objective This Agent paper summarizes the findings and recommendations of the Agent (product) Working Group of the November, 2002, National Tobacco Monitoring, Research and Evaluation Workshop. Methods The Agent Working Group evaluated the need to develop new surveillance systems for quantifying ingredients and emissions of tobacco and tobacco smoke and to improve methods to assess uptake and metabolism of these constituents taking into account variability in human smoking behavior. Results The toxic properties of numerous tobacco and tobacco smoke constituents are well known, yet systematic monitoring of tobacco products has historically been limited to tar, nicotine, and CO in mainstream cigarette smoke using a machine-smoking protocol that does not reflect human smoking behavior. Toxicity of smokeless tobacco products has not been regularly monitored. Tobacco products are constantly changing and untested products are introduced into the marketplace with great frequency, including potential reduced-exposure products (PREPs). The public health impact of new or modified tobacco products is unknown. Conclusions Systematic surveillance is recommended for mainstream smoke constituents such as polycyclic aromatic hydrocarbons (PAH), tobacco-specific nitrosamines (TSNA), total and free-base nicotine, volatile organic compounds, aromatic amines, and metals; and design attributes including tobacco blend, additives, and filter ventilation. Research on smoking topography is recommended to help define machine-smoking protocols for monitoring emissions reflective of human smoking behavior. Recommendations are made for marketplace product sampling and for population monitoring of smoking topography, emissions of toxic constituents, biomarkers of exposure and, eventually, risk of tobacco-related diseases. PMID:18848577

Understanding the fate and transport of petroleum hydrocarbons from coal tar within gasholders.

PubMed

Coulon, Frédéric; Orsi, Roberto; Turner, Claire; Walton, Chris; Daly, Paddy; Pollard, Simon J T

2009-02-01

Coal tars have been identified as posing a threat to human health due to their toxic, mutagenic and carcinogenic characteristics. Workers involved in former gasholders decommissioning are potentially exposed to relevant concentrations of volatile and semi-volatile hydrocarbons upon opening up derelict tanks and during tar excavation/removal. While information on contaminated sites air-quality and its implications on medium-long term exposure is available, acute exposure issues associated with the execution of critical tasks are less understood. Calculations indicated that the concentration of a given contaminant in the gasholder vapour phase only depends on the coal tar composition, being only barely affected by the presence of water in the gasholder and the tar volume/void space ratio. Fugacity modelling suggested that risk-critical compounds such as benzene, naphthalene and other monocyclic and polycyclic aromatic hydrocarbons may gather in the gasholder air phase at significant concentrations. Gasholder emissions were measured on-site and compared with the workplace exposure limits (WELs) currently in use in UK. While levels for most of the toxic compounds were far lower than WELs, benzene air-concentrations where found to be above the accepted threshold. In addition due to the long exposure periods involved in gasholder decommissioning and the significant contribution given by naphthalene to the total coal tar vapour concentration, the adoption of a WEL for naphthalene may need to be considered to support operators in preventing human health risk at the workplace. The Level I fugacity approach used in this study demonstrated its suitability for applications to sealed environments such as gasholders and its further refining could provide a useful tool for land remediation risk assessors.

Origin of Chlorobenzene Detected by the Curiosity Rover in Yellowknife Bay: Evidence for Martian Organics in the Sheepbed Mudstone?

NASA Technical Reports Server (NTRS)

Glavin, Daniel P.; Freissinet, Caroline; Eigenbrode, J.; Miller, K.; Martin, M.; Summons, R.; Steele, A.; Franz, H.; Archer, D.; Brinkerhoff, W.;

Verifying Sensor Response to Difficult Chemicals with a New Test Chamber Concept

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

In this article we discuss the application of technology innovations to optimize detection of hard-to-measure (less- or semi-volatile) compounds. These chemicals are found all around us: in pesticides and herbicides, the higher boiling polyaromatic hydrocarbons in diesel exhaust, and linked polyurethane foams in products ranging from hiking boots to acoustic ceilings. They appear in low concentrations and evaporate very slowly. These heavier chemicals are rarely measured accurately because they stick to surfaces and sampling equipment and, consequently, are not reliably sampled or delivered to analytical detectors. It’s like trying to identify cold, sticky honey by getting it to flow inmore » through a sampling tube to a detector –it will hardly move. Honey generally coats out on surfaces and sample lines to the extent that even if it is detected, the amount present is vastly underestimated. Researchers at Pacific Northwest National Laboratory (PNNL) addressed the problem by developing a chamber facility with instrumentation that can overcome the under-reporting of these ubiquitous chemical compounds. The atmospheric chemistry chamber provides a controlled environment in which to certify the accuracy of and conditions under which sensors can best respond to volatile and semi-volatile chemicals. The facility is designed to handle and measure chemicals at the levels at which they are found in nature. Test environments can be created in which atmospheric concentrations are at low part-per-trillion concentrations. These concentrations are equivalent to an herbicide off-gassing from a commercially grown apple. The chamber can be set up to simulate releases ranging from industrial vents with high concentrations to releases from surfaces, soils, and/or vegetation where the concentrations are low.« less

Aqueous-Phase Reactions of Isoprene with Sulfoxy Radical Anions as a way of Wet Aerosol Formation in the Atmosphere

NASA Astrophysics Data System (ADS)

Kuznietsova, I.; Rudzinski, K. J.; Szmigielski, R.; Laboratory of the Environmental Chemistry

2011-12-01

Atmospheric aerosols exhibit an important role in the environment. They have implications on human health and life, and - in the larger scale - on climate, the Earth's radiative balance and the cloud's formation. Organic matter makes up a significant fraction of atmospheric aerosols (~35% to ~90%) and may originate from direct emissions (primary organic aerosol, POA) or result from complex physico-chemical processes of volatile organic compounds (secondary organic aerosol, SOA). Isoprene (2-methyl-buta-1,3-diene) is one of the relevant volatile precursor of ambient SOA in the atmosphere. It is the most abundant non-methane hydrocarbon emitted to the atmosphere as a result of living vegetation. According to the recent data, the isoprene emission rate is estimated to be at the level of 500 TgC per year. While heterogeneous transformations of isoprene have been well documented, aqueous-phase reactions of this hydrocarbon with radical species that lead to the production of new class of wet SOA components such as polyols and their sulfate esters (organosulfates), are still poorly recognized. The chain reactions of isoprene with sulfoxy radical-anions (SRA) are one of the recently researched route leading to the formation of organosulfates in the aqueous phase. The letter radical species originate from the auto-oxidation of sulfur dioxide in the aqueous phase and are behind the phenomenon of atmospheric acid rain formation. This is a complicated chain reaction that is catalyzed by transition metal ions, such as manganese(II), iron(III) and propagated by sulfoxy radical anions . The presented work addresses the chemical interaction of isoprene with sulfoxy radical-anions in the water solution in the presence of nitrite ions and nitrous acid, which are important trace components of the atmosphere. We showed that nitrite ions and nitrous acid significantly altered the kinetics of the auto-oxidation of SO2 in the presence of isoprene at different solution acidity from 2 to 8.7. The presence of nitrogen-containing inorganic salts strongly impact the formation of novel organosulfur products, whereas no organonitrates were observed. A detailed characterization of these products with the triple-quadruple negative electrospray mass spectrometry (-)ESI-MS/MS revealed oxygenated polar species with C-5 skeleton bearing SO3H (MW 182, 180) and SO2H (MW 166, 164) moieties on the hydroxyl group. The structures of these products were firmly confirmed by comparison of their liquid chromatography and mass spectrometry behaviors with that corresponding to the synthesized model compounds. It is believed that newly discovered highly polar low molecular weight compounds may contribute to the growth of wet aerosol particles by the formation of higher molecular weight species.

Impact of pollution controls in Beijing on atmospheric oxygenated volatile organic compounds (OVOCs) during the 2008 Olympic Games: observation and modeling implications

NASA Astrophysics Data System (ADS)

Liu, Y.; Yuan, B.; Li, X.; Shao, M.; Lu, S.; Li, Y.; Chang, C.-C.; Wang, Z.; Hu, W.; Huang, X.; He, L.; Zeng, L.; Hu, M.; Zhu, T.

2015-03-01

Oxygenated volatile organic compounds (OVOCs) are important products of the photo-oxidation of hydrocarbons. They influence the oxidizing capacity and the ozone-forming potential of the atmosphere. In the summer of 2008, 2 months of emission restrictions were enforced in Beijing to improve air quality during the Olympic Games. Observational evidence reported in related studies that these control measures were efficient in reducing the concentrations of primary anthropogenic pollutants (CO, NOx and non-methane hydrocarbons, i.e., NMHCs) by 30-40%. In this study, the influence of the emission restrictions on ambient levels of OVOCs was explored using a neural network analysis with consideration of meteorological conditions. Statistically significant reductions in formaldehyde (HCHO), acetaldehyde (CH3CHO), methyl ethyl ketone (MEK) and methanol were found to be 12.9, 15.8, 17.1 and 19.6%, respectively, when the restrictions were in place. The effect of emission controls on acetone was not detected in neural network simulations, probably due to pollution transport from surrounding areas outside Beijing. Although the ambient levels of most NMHCs were reduced by ~35% during the full control period, the emission ratios of reactive alkenes and aromatics closely related to automobile sources did not present much difference (< 30%). A zero-dimensional box model based on the Master Chemical Mechanism version 3.2 (MCM3.2) was applied to evaluate how OVOC production responds to the reduced precursors during the emissions control period. On average, secondary HCHO was produced from the oxidation of anthropogenic alkenes (54%), isoprene (30%) and aromatics (15%). The importance of biogenic sources for the total HCHO formation was almost on par with that of anthropogenic alkenes during the daytime. Anthropogenic alkenes and alkanes dominated the photochemical production of other OVOCs such as acetaldehyde, acetone and MEK. The relative changes of modeled HCHO, CH3CHO, methyl vinyl ketone and methacrolein (MVK + MACR) before and during the pollution controlled period were comparable to the estimated reductions in the neural network, reflecting that current mechanisms can largely explain secondary production of those species under urban conditions. However, it is worth noting that the box model overestimated the measured concentrations of aldehydes by a factor of 1.4-1.7 without consideration of loss of aldehydes on aerosols, and simulated MEK was in good agreement with the measurements when primary sources were taken into consideration. These results suggest that the understanding of the OVOCs budget in the box model remains incomplete, and that there is still considerable uncertainty in particular missing sinks (unknown chemical and physical processes) for aldehydes and absence of direct emissions for ketones.

Sonolysis of hydrocarbons in aqueous solution

NASA Astrophysics Data System (ADS)

Hart, Edwin J.; Fischer, Christian-Herbert; Henglein, Arnim

Water was irradiated with 300 kHz ultrasound under an argon atmosphere containing various amounts of methane and ethane. Limited studies were also made on ethylene, acetylene, propane and butane. The methane and ethane irradiations were carried out over the hydrocarbon-argon range of 2-100%. Maximum decomposition occurs at 15% for methane and 10% for ethane. While hydrogen is a dominant product in both cases, acetylene, ethylene and ethane are prominent products, too. Propane, propene and propin form in lesser quantities. 2-methyl-propane, n-butane, l-butene, 2-methyl-butene, butadiene and n-butin have also been identified. These hydrocarbons are similar to those found in pyrolysis and in fuel rich combustion experiments. Carbon monoxide is an important product at hydrocarbon concentrations less than 40% establishing water was an oxygen delivering reactant under these conditions. In the case of methane, the ratio of ethylene plus acetylene to ethane is used to estimate the effective temperature in the cavitation bubble. A temperature of about 2800 K is obtained for bubbles containing argon (plus water vapor and 20% CH 4) and T = 2000 K for pure methane. The rate of decomposition for unsaturated hydrocarbons is substantially greater than for the saturated ones. Low molecular weight products are mainly formed from saturated hydrocarbons whereas polymerization products are mainly formed from the unsaturated hydrocarbons. The decomposition of acetylene in argon bubbles is one of the fastest sonolytic processes.

A case study of the intrinsic bioremediation of petroleum hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barker, G.W.; Raterman, K.T.; Fisher, J.B.

1995-12-31

Condensate liquids have been found to contaminate soil and groundwater at two gas production sites in the Denver Basin operated by Amoco Production Co. These sites have been closely monitored since July 1993 to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores suggest that intrinsic bioremediation is occurring at these sites by multiple pathways including aerobic oxidation, Fe{sup 3+} reduction, and sulfate reduction. In laboratory experiments the addition of gas condensate hydrocarbons to saturated soil from themore » gas production site stimulated sulfate reduction under anaerobic and oxygen-limiting conditions, and nitrate and Fe{sup 3+} reduction under oxygen-limiting conditions, compared to biotic controls that lacked hydrocarbon and sterile controls. The sulfate reduction corresponded to a reduction in the amount of toluene relative to other hydrocarbons. These results confirmed that subsurface soils at the gas production site have the potential for intrinsic bioremediation of hydrocarbons.« less

Source apportionment of chlorinated polycyclic aromatic hydrocarbons associated with ambient particles in a Japanese megacity

PubMed Central

Kamiya, Yuta; Iijima, Akihiro; Ikemori, Fumikazu; Okuda, Tomoaki; Ohura, Takeshi

2016-01-01

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are novel species of environmental contaminants whose possible sources remain unclear. The occurrence of ClPAHs within total suspended particles (TSP) is compared with weekly air samples at two sites of differing characteristics (industrial and residential) in the megacity of Nagoya, Japan. Samples were collected over 12 months during 2011–2012. All 24 species of targeted ClPAHs were detected at both industrial and residential sites, where mean concentrations of total ClPAHs in TSP were 20.7 and 14.1 pg/m3, respectively. High concentrations at the industrial site were frequently observed during winter, suggesting potent seasonal ClPAH sources there. Positive matrix factorization modeling of particulate ClPAH source identification and apportioning were conducted for datasets including ClPAHs, PAHs, elements and ions, plus elemental carbons in TSP. Eight factors were identified as possible ClPAH sources, with estimates that the dominant one was a specific source of ClPAH emission (31%), followed by traffic (23%), photodegradable and semi-volatile species (18%), long-range transport (11%), and industry and oil combustion (10%). Source contributions of ClPAHs differed substantially from those of PAHs. This suggests specific and/or potent ClPAH sources in the local area, and that the production mechanisms between ClPAHs and PAHs are substantially different. PMID:27922081

Monitoring ethylene emissions from plants cultured for a controlled ecological life support system

NASA Technical Reports Server (NTRS)

Corey, Kenneth A.

1995-01-01

Emission of hydrocarbons and other volatile compounds by materials and organisms in closed environments will be a major concern in the design and management of advanced life support systems with a bioregenerative component. Ethylene, a simple hydrocarbon synthesized by plants, is involved in the elicitation of a wide range of physiological responses. In closed environments, ethylene may build up to levels which become physiologically active. In several growouts of 'Yecora Rojo' wheat in Kennedy Space Center's Biomass Production Chamber (BPC), it was observed that leaf flecking and rolling occurred in the sealed environment and was virtually eliminated when potassium permanganate was used to scrub the atmospheric environment. It was suggested that ethylene, which accumulated to about 60 ppb in the chamber and which was effectively absorbed by potassium permanganate, was responsible for the symptoms. The objectives of this work were to: (1) determine rates of ethylene evolution from lettuce (Lactuca sativa cultivar Waldemann's Green) and wheat (Triticum aestivum cultivar Yecora Rojo) plants during growth and development; (2) determine the effects of exposure of whole, vegetative stage plants to exogenous ethylene concentrations in the range of what would develop in closed environment growth chambers; and (3) develop predictive functions for changes in ethylene concentration that would develop under different cropping and closed environment configurations. Results will lead to the development of management strategies for ethylene in bioregenerative life support systems.

Revealing the properties of oils from their dissolved hydrocarbon compounds in water with an integrated sensor array system.

PubMed

Qi, Xiubin; Crooke, Emma; Ross, Andrew; Bastow, Trevor P; Stalvies, Charlotte

2011-09-21

This paper presents a system and method developed to identify a source oil's characteristic properties by testing the oil's dissolved components in water. Through close examination of the oil dissolution process in water, we hypothesise that when oil is in contact with water, the resulting oil-water extract, a complex hydrocarbon mixture, carries the signature property information of the parent oil. If the dominating differences in compositions between such extracts of different oils can be identified, this information could guide the selection of various sensors, capable of capturing such chemical variations. When used as an array, such a sensor system can be used to determine parent oil information from the oil-water extract. To test this hypothesis, 22 oils' water extracts were prepared and selected dominant hydrocarbons analyzed with Gas Chromatography-Mass Spectrometry (GC-MS); the subsequent Principal Component Analysis (PCA) indicates that the major difference between the extract solutions is the relative concentration between the volatile mono-aromatics and fluorescent polyaromatics. An integrated sensor array system that is composed of 3 volatile hydrocarbon sensors and 2 polyaromatic hydrocarbon sensors was built accordingly to capture the major and subtle differences of these extracts. It was tested by exposure to a total of 110 water extract solutions diluted from the 22 extracts. The sensor response data collected from the testing were processed with two multivariate analysis tools to reveal information retained in the response patterns of the arrayed sensors: by conducting PCA, we were able to demonstrate the ability to qualitatively identify and distinguish different oil samples from their sensor array response patterns. When a supervised PCA, Linear Discriminate Analysis (LDA), was applied, even quantitative classification can be achieved: the multivariate model generated from the LDA achieved 89.7% of successful classification of the type of the oil samples. By grouping the samples based on the level of viscosity and density we were able to reveal the correlation between the oil extracts' sensor array responses and their original oils' feature properties. The equipment and method developed in this study have promising potential to be readily applied in field studies and marine surveys for oil exploration or oil spill monitoring.

The pollution characteristics of odor, volatile organochlorinated compounds and polycyclic aromatic hydrocarbons emitted from plastic waste recycling plants.

PubMed

Tsai, Chung-Jung; Chen, Mei-Lien; Chang, Keng-Fu; Chang, Fu-Kuei; Mao, I-Fang

2009-02-01

Plastic waste treatment trends toward recycling in many countries; however, the melting process in the facilities which adopt material recycling method for treating plastic waste may emit toxicants and cause sensory annoyance. The objectives of this study were to analyze the pollution characteristics of the emissions from the plastic waste recycling plants, particularly in harmful volatile organochlorinated compounds, polycyclic aromatic hydrocarbons (PAHs), odor levels and critical odorants. Ten large recycling plants were selected for analysis of odor concentration (OC), volatile organic compounds (VOCs) and PAHs inside and outside the plants using olfactometry, gas chromatography-mass spectrometry and high performance liquid chromatography-fluorescence detector, respectively. The olfactometric results showed that the melting processes used for treating polyethylene/polypropylene (PE/PP) and polyvinyl chloride (PVC) plastic waste significantly produced malodor, and the odor levels at downwind boundaries were 100-229 OC, which all exceeded Taiwan's EPA standard of 50 OC. Toluene, ethylbenzene, 4-methyl-2-pentanone, methyl methacrylate and acrolein accounted for most odors compared to numerous VOCs. Sixteen organochlorinated compounds were measured in the ambient air emitted from the PVC plastic waste recycling plant and total concentrations were 245-553 microg m(-3); most were vinyl chloride, chloroform and trichloroethylene. Concentrations of PAHs inside the PE/PP plant were 8.97-252.16 ng m(-3), in which the maximum level were 20-fold higher than the levels detected from boundaries. Most of these recycling plants simply used filter to treat the melting fumes, and this could not efficiently eliminate the gaseous compounds and malodor. Improved exhaust air pollution control were strongly recommended in these industries.

Sensory characteristics and volatile composition of a cereal beverage fermented with Bifidobacterium breve NCIMB 702257.

PubMed

Salmerón, Ivan; Rozada, Raquel; Thomas, Keith; Ortega-Rivas, Enrique; Pandiella, Severino S

2014-04-01

Most of the commercialized lactic acid fermented products are dairy-based. Hence, the development of non-dairy fermented products with probiotic properties draws significant attention within the functional foods industry. The microorganisms used in such products have complex enzyme systems through which they generate diverse metabolites (volatile and non-volatile) that provide significant flavour attributes of importance for fermented foods. The correlation of the volatile flavour compounds of a malt beverage fermented with a Bifidobacterium breve strain with its unique sensory characteristics was performed. The volatile composition analysis exposed the presence of 12 components. Eight of these flavour volatiles were produced through the metabolic activity of the bifidobacteria strain. Notably acetic acid, of reported sour flavour characteristics, exhibited the greatest intensity. Four components of considerable organoleptic characteristics were identified as Maillard-derived products, namely maltol, pyranone, 2 (5H)-furanmethanol and 3-furanmethanol. The sensory evaluation exhibited that the fermented cereal beverage had a sour flavour with mild sweet and malty notes. These results indicate that the volatile compounds identified can be appointed as significant flavour markers of the novel fermented cereal beverage.

Metabolic engineering of Saccharomyces cerevisiae for production of fatty acid-derived hydrocarbons.

PubMed

Zhang, Yiming; Nielsen, Jens; Liu, Zihe

2018-06-05

Fatty acid-derived hydrocarbons attract increasing attention as biofuels due to their immiscibility with water, high-energy content, low freezing point, and high compatibility with existing refineries and end-user infrastructures. Yeast Saccharomyces cerevisiae has advantages for production of fatty acid-derived hydrocarbons as its native routes toward fatty acid synthesis involve only a few reactions that allow more efficient conversion of carbon substrates. Here we describe major biosynthetic pathways of fatty acid-derived hydrocarbons in yeast, and summarize key metabolic engineering strategies, including enhancing precursor supply, eliminating competing pathways, and expressing heterologous pathways. With recent advances in yeast production of fatty acid-derived hydrocarbons, our review identifies key research challenges and opportunities for future optimization, and concludes with perspectives and outlooks for further research directions. © 2018 Wiley Periodicals, Inc.

Analyzing volatile compounds in dairy products

USDA-ARS?s Scientific Manuscript database

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

[Sources analysis and contribution identification of polycyclic aromatic hydrocarbons in indoor and outdoor air of Hangzhou].

PubMed

Liu, Y; Zhu, L; Wang, J; Shen, X; Chen, X

2001-11-01

Twelve polycyclic aromatic hydrocarbons (PAHs) were measured in eight homes in Hangzhou during the summer and autumn in 1999. The sources of PAHs and the contributions of the sources to the total concentration of PAHs in the indoor air were identified by the combination of correlation analysis, factor analysis and multiple regression, and the equations between the concentrations of PAHs in indoor and outdoor air and factors were got. It was indicated that the factors of PAHs in the indoor air were domestic cuisine, the volatility of the mothball, cigarette smoke and heating, the waste gas from vehicles. In the smokers' home, cigarette smoke was the most important factor, and it contributed 25.8% of BaP to the indoor air of smokers' home.

Dominierende Prozesse bei der thermischen In-situ-Sanierung (TISS) kontaminierter Geringleiter

NASA Astrophysics Data System (ADS)

Hiester, Uwe; Bieber, Laura

2017-09-01

Contaminants such as chlorinated, aromatic or polycyclic aromatic hydrocarbons (CHC, BTEX, PAH) or mineral oil hydrocarbons (TPH) constitute a prevalent threat to water resources. The significant storage capacity of low permeable soils (aquitards) leads to their long-term contamination. In situ thermal remediation (ISTR) proved to work successfully in treating these soils. Thus, the area of ISTR application grew continuously over the past 10 years. The dominating processes during the remediation can vary considerably, depending on hydrogeological and geological boundary conditions and the contamination itself. This article summarizes the application for in-situ thermal remediation (ISTR) in low permeable soils and aquitards for soil and groundwater treatment. Dominating remediation processes during volatile organic compound (VOC) and residual oil phase recovery are presented. The processes are illustrated by project examples.

Oxidation catalysts comprising metal exchanged hexaaluminate wherein the metal is Sr, Pd, La, and/or Mn

DOEpatents

Wickham, David [Boulder, CO; Cook, Ronald [Lakewood, CO

2008-10-28

The present invention provides metal-exchanged hexaaluminate catalysts that exhibit good catalytic activity and/or stability at high temperatures for extended periods with retention of activity as combustion catalysts, and more generally as oxidation catalysts, that make them eminently suitable for use in methane combustion, particularly for use in natural gas fired gas turbines. The hexaaluminate catalysts of this invention are of particular interest for methane combustion processes for minimization of the generation of undesired levels (less than about 10 ppm) of NOx species. Metal exchanged hexaaluminate oxidation catalysts are also useful for oxidation of volatile organic compounds (VOC), particularly hydrocarbons. Metal exchanged hexaaluminate oxidation catalysts are further useful for partial oxidation, particularly at high temperatures, of reduced species, particularly hydrocarbons (alkanes and alkenes).

Non-destructive profiling of volatile organic compounds using HS-SPME/GC-MS and its application for the geographical discrimination of white rice.

PubMed

Lim, Dong Kyu; Mo, Changyeun; Lee, Dong-Kyu; Long, Nguyen Phuoc; Lim, Jongguk; Kwon, Sung Won

2018-01-01

The authenticity determination of white rice is crucial to prevent deceptive origin labeling and dishonest trading. However, a non-destructive and comprehensive method for rapidly discriminating the geographical origins of white rice between countries is still lacking. In the current study, we developed a volatile organic compound based geographical discrimination method using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME/GC-MS) to discriminate rice samples from Korea and China. A partial least squares discriminant analysis (PLS-DA) model exhibited a good classification of white rice between Korea and China (accuracy = 0.958, goodness of fit = 0.937, goodness of prediction = 0.831, and permutation test p-value = 0.043). Combining the PLS-DA based feature selection with the differentially expressed features from the unpaired t-test and significance analysis of microarrays, 12 discriminatory biomarkers were found. Among them, hexanal and 1-hexanol have been previously known to be associated with the cultivation environment and storage conditions. Other hydrocarbon biomarkers are novel, and their impact on rice production and storage remains to be elucidated. In conclusion, our findings highlight the ability to rapidly discriminate white rice from Korea and China. The developed method maybe useful for the authenticity and quality control of white rice. Copyright © 2017. Published by Elsevier B.V.

Relations between Land Use and Organochlorine Pesticides, PCBs, and Semi-Volatile Organic Compounds in Streambed Sediment and Fish on the Island of Oahu, Hawaii

USGS Publications Warehouse

Brasher, A.M.D.; Wolff, R.H.

2004-01-01

Bed-sediment and/or fish samples were collected from 27 sites around the island of Oahu (representing urban, agricultural, mixed, and forested land use) to determine the occurrence and distribution of hydrophobic organic compounds including organochlorine pesticides, polychlorinated biphenyls (PCBs), and semi-volatile organic compounds (SVOCs). Of the 28 organochlorine compounds analyzed in the fish, 14 were detected during this study. Nineteen of the 31 organochlorine compounds and 40 of the 65 SVOCs were detected in the sediment. Urban sites had the highest number of detections and tended to have the highest concentrations of pesticides. Chlordane compounds were the most frequently detected constituents at urban sites, followed by dieldrin, polycyclic aromatic hydrocarbons (PAHs), and DDT compounds. PAHs were the most frequently detected constituents in watersheds with mixed (urban and agricultural) land use. The only pesticides detected at agricultural sites were DDT and its degradation products, DDD and DDE. No pesticides or PCBs were detected at the forested sites, but a few ubiquitous SVOCs were found in sediments at some forested sites. In general, concentrations of the most frequently detected pesticides were higher in fish than in sediment. Following a trend that has been observed elsewhere in the nation, concentrations of most organochlorine pesticides and PCBs are decreasing in Hawaii.

Suicide attempt by intravenous injection of gasoline: a case report.

PubMed

Fink, Katrin; Kuehnemund, Alexander; Schwab, Tilmann; Geibel-Zehender, Annette; Bley, Thorsten; Bode, Christoph; Busch, Hans-Joerg

2010-11-01

There is much experience with intoxication by aspiration of volatile hydrocarbon products, whereas intravenous injection of these distillates is rare. There are only few reports that describe a wide variety of associated pathological changes, predominantly in the pulmonary system. We report the case of an intravenous self-injection of gasoline by a young man in a suicide attempt. Immediately after injecting gasoline, the 22-year-old man developed bradycardia, hypotension, and increasing dyspnea. Computed tomography scan of the chest showed signs consistent with diffuse alveolar-toxic damage to the lung. These symptoms and radiological findings are similar to those commonly observed after inhalation of this type of substance. This may have been due to diffusion of gasoline into the alveoli, where its presence leads to this characteristic damage. In this patient, gasoline entered the intramuscular tissue, and the patient developed a soft-tissue phlegmon at the forearm. At operation, gas emanation and superficial necrosis were noted. Nevertheless, the patient's outcome was good, with full recovery within 3 weeks. The major changes in this patient after intravenous injection of gasoline were in the pulmonary system, including hypoxemia and radiological findings that could be related to an exhalation of the volatile substance. In addition, gas in the musculature of the injection area caused a soft-tissue phlegmon. Copyright © 2010 Elsevier Inc. All rights reserved.