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1

Effect of fuel polycyclic aromatic hydrocarbon content on the emissions of polycyclic aromatic hydrocarbons and other mutagenic substances from a gasoline-fueled automobile  

Microsoft Academic Search

Exhaust emissions from a fuel-injected, Otto engine equipped car driven according to the US Federal Test Procedure (FTP-73) were characterized chemically and by mutagenicity tests. Four fuel qualities of different polycyclic aromatic hydrocarbon (PAH) content were used. Emission variables investigated were regulated pollutants (CO, unburned hydrocarbons, NO\\/sub x\\/), particle emissions, emission of particle and gas phase associated polycyclic aromatic hydrocarbons,

Roger N. Westerholm; Tomas E. Alsberg; Aake B. Frommelin; Michael E. Strandell; Ulf Rannug; Lars Winquist; Vassilios Grigoriadis; Karl Erik Egebaeck

1988-01-01

2

Polycyclic aromatic hydrocarbons in spanish olive oils: relationship between benzo(a)pyrene and total polycyclic aromatic hydrocarbon content.  

PubMed

Samples of Spanish virgin olive oils (VOOs) from different categories, origins, varieties, and commercial brands were analyzed by HPLC with a programmable fluorescence detector to determine the content of nine heavy polycyclic aromatic hydrocarbons (PAHs): benzo(a)anthracene, chrysene, benzo(e)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perilene, and indeno(1,2,3-c,d)pyrene. Samples of olive pomace and crude olive pomace oils were also investigated. Benzo(a)pyrene concentrations were below the allowed limit in the European Union (2 microg/kg) in 97% of the VOO samples. Only those samples coming from contaminated olive fruits or obtained in oil mills with highly polluted environments exceeded this value. High correlation coefficients (<0.99) were obtained between the contents of benzo(a)pyrene and the sum of the nine PAHs for all of the analyzed categories, suggesting that benzo(a)pyrene could be used as a marker of the content of these nine PAHs in olive oils. PMID:18831590

Rodríguez-Acuña, Rafael; del Carmen Pérez-Camino, María; Cert, Arturo; Moreda, Wenceslao

2008-10-03

3

Effect of fuel polycyclic aromatic hydrocarbon content on the emissions of polycyclic aromatic hydrocarbons and other mutagenic substances from a gasoline-fueled automobile  

SciTech Connect

Exhaust emissions from a fuel-injected, Otto engine equipped car driven according to the US Federal Test Procedure (FTP-73) were characterized chemically and by mutagenicity tests. Four fuel qualities of different polycyclic aromatic hydrocarbon (PAH) content were used. Emission variables investigated were regulated pollutants (CO, unburned hydrocarbons, NO/sub x/), particle emissions, emission of particle and gas phase associated polycyclic aromatic hydrocarbons, aldehyde emissions, emissions of benzene, toluene, ethene, and propene, and mutagenicity in particle and gas phases. The amount of formed PAH emitted in the exhaust is approximately constant. In fuels with low PAH contents a large proportion of emitted PAH was formed. Most of the cyclopenta(cd)pyrene and benzo(b and k) fluoranthene, greater than or equal to 80% and greater than or equal to 70%, respectively, is formed in the combustion process. All the exhaust samples, except one, in both the particulate phase and the gas phase, gave significant mutagenic effects on Salmonella typhimurium tester strains TA98 and TA100 with or without a metabolizing system (S9). Generally, the gas phase gave a higher effect compared to the particulate phase. The best correlation between emitted PAH and mutagenicity was found for the particulate phase and TA100+S9.

Westerholm, R.N.; Alsberg, T.E.; Frommelin, A.B.; Strandell, M.E.; Rannug, U.; Winquist, L.; Grigoriadis, V.; Egebaeck, K.E.

1988-08-01

4

Profile analysis of polycyclic aromatic hydrocarbons and metal content in sediment layers of a lake.  

PubMed

The question is investigated whether polycyclic aromatic hydrocarbons (PAH) in the annual sediment layers of a lake mainly result from air dust pollution. Sample layers taken from drilling cores going back to 1915 show no significant differences at the forest shore (no buildings) during this period. In contrast, samples taken from a built-up area of the shore (with a highway and a main railway line) show today 5 times the amount of PAH compared with 1915. The same trend is observed in the content of Zn, whereas Pb, Fe, Cr, Ni, Cu and Mn levels are constant. Identification or characterization of PAH was accomplished by comparison of the retention times and mass spectrometry of authentic compounds. Sixty-four PAH are described. The results indicate that the burden of carcinogenic PAH air pollutants has increased 5-fold from 1915-1970. PMID:1235063

Grimmer, G; Böhnke, H

1975-11-01

5

Biodegradation of polycyclic aromatic hydrocarbons in the natural waters of the Yellow River: Effects of high sediment content on biodegradation  

Microsoft Academic Search

The contamination of polycyclic aromatic hydrocarbons (PAHs) has become one of the major problems in the Yellow River of China. As the Yellow River is the most turbid large river in the world, it remains unknown to which extent the high suspended sediment content in the river may affect the fate and effect of PAHs. Here we report the effect

X. H. Xia; H. Yu; Z. F. Yang; G. H. Huang

2006-01-01

6

Mutagenicity and polycyclic aromatic hydrocarbon content of fumes from heated cooking oils produced in Taiwan  

Microsoft Academic Search

According to epidemiologic studies, exposure of women to fumes from cooking oils appears to be an important risk factor for lung cancer. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and analyzed for mutagenicity in the Salmonella\\/microsome assay. Polycyclic aromatic hydrocarbons were extracted from the samples and identified by HPLC chromatography. Extracts from three

Tai-An Chiang; Pei-Fen Wu; Li-Fang Wang; Huei Lee; Chien-Hung Lee; Ying-Chin Ko

1997-01-01

7

The mutagenic activity and polycyclic aromatic hydrocarbon content of mineral oils.  

PubMed

Naphthenic distillates (raw or acid-treated) and motor and emulsifiable aluminium rolling oils were tested for mutagenicity in the Salmonella/microsome assay using the TA98 and TA100 strains. The polycyclic aromatic hydrocarbon (PAH) content of oil samples was also determined in parallel. In the presence of metabolic activation, both untreated and acid-treated naphthenic distillates were found to be mutagenic on a modified Ames test. One untreated sample showed the highest value of mutagenic potency (50 net revertants/mg oil for strain TA98). The PAH content of naphthenic distillates was about 10% (w/w) and was slightly reduced by sulfuric acid/earth treatment (1%). Non-mutagenic paraffin- and solvent-extracted crankcase oils became active, both with and without enzyme activation, after long use as gasoline engine lubricants, whereby their PAH content doubled (from 1.5% to 3%, w/w). A refined emulsifiable mineral oil also became directly mutagenic in both Salmonella strains after prolonged use in an aluminium hot-rolling mill. As the PAH levels found in used rolling oils was very low, we cannot explain their mutagenic activity. Mutagenicity was greatly reduced following careful cleaning of the oil bath and of the entire rolling machine. The present data reveal both the potential risk of occupational exposure to unrefined or mildly treated oils and the formation of mutagens in highly refined oils if the latter are used at high temperatures. The formation of mutagens in oils used in the metal-working industry can be prevented by careful industrial hygiene measures. PMID:1889886

Granella, M; Clonfero, E

1991-01-01

8

Polycyclic Aromatic Hydrocarbons  

NSDL National Science Digital Library

The featured molecules for the month of February are a number of polycyclic aromatic hydrocarbons (PAHs) discussed in the article "Fluorescence, Absorption, and Excitation Spectra of Polycyclic Aromatic Hydrocarbons as a Tool for Quantitative Analysis". PAHs are ubiquitous in air, soils, and water as a result of both direct and indirect emissions. PAHs are discharged into environments as byproducts of the combusion of fossil fuels used for transportation and generation of electricity. Other sources of PAH emissions include industrial processes, biomass burning, waste incineration, oil spills, and cigarette smoke.

9

Influence of Agricultural Land Use and Management on the Contents of Polycyclic Aromatic Hydrocarbons in Selected Silty Soils  

Microsoft Academic Search

The aim of the present study was the influence of various methods of long-term soil utilisation on the content of polycyclic\\u000a aromatic hydrocarbons (PAH) in selected silty soils. Four soils were selected for the present studies, i.e.: Eutric Fluvisol originating from silty formations, Haplic Phaeozem developed from loess, Haplic Luvisol (non-uniform) developed from silt, Haplic Luvisol developed from loess. Five

Patryk Oleszczuk; Jacek Pranagal

2007-01-01

10

Effects of air\\/fuel combustion ratio on the polycyclic aromatic hydrocarbon content of carbonaceous soots from selected fuels  

Microsoft Academic Search

Patterns of polycyclic aromatic hydrocarbon (PAH) content were observed from GC\\/MS analysis of the extracts of soots at various air\\/fuel combustion ratios of three commonly used fuels: n-hexane, JP-8 (Jet fuel), and diesel. With increasing air\\/fuel ratio, from a simple diffusion flame up to an air\\/fuel ratio of 3.94, there is a significant loss of high molecular weight PAHs and

C. C. Jones; A. R. Chughtai; B. Murugaverl; D. M. Smith

2004-01-01

11

Factors affecting the polycyclic aromatic hydrocarbon content of cereals, fats and other food products.  

PubMed

Factors affecting polycyclic aromatic hydrocarbon (PAH) concentrations in oils and fats, cereals and related foodstuffs have been investigated. Levels of PAHs were low in retail fish and animal-derived oils and fats, such as butter, where the mean benzo(a)pyrene concentration was 0.06 microgram/kg. Higher and more variable amounts were present in retail vegetable oils for which the mean level of benzo(a)pyrene was 1.29 micrograms/kg. Margarine was the major dietary source of PAHs in the oils and fats total diet group accounting for 70% of the benzo(a)pyrene intake from these commodities. The levels of benzo(a)pyrene were less than 0.1 microgram/kg in white flour and similar amounts were found in bread showing that PAHs are not formed to any significant extent during baking of bread. Higher concentrations of up to 2.2 micrograms/kg benzo(a)pyrene were detected in cereal-derived products containing higher levels of edible oils such as pudding-based desserts, biscuits and cakes. The presence of vegetable oils as an ingredient also appeared to increase PAH levels in infant formulae as the mean benzo(a)pyrene content of 0.49 microgram/kg was four times higher than that found in skimmed milk. The mean value in the feed, after reconstituting the formulae with water, would however have been less than 0.1 microgram/litre. Investigations of rape seed drying showed no increase in any PAHs when cold, or electrically-heated air was used. Combustion gas drying had no effect for the larger PAHs such as benzo(a)pyrene but caused mean increases of between 41% and 126% for fluoranthene, pyrene and chrysene. These increases did not correlate with reductions in moisture content of the rape seed implying that the combustion conditions were more important to PAH contamination than the degree of exposure to combustion gases. Concentrations of these three PAHs and also benz(a)anthracene were all significantly reduced by up to a factor of five when crude oils were refined suggesting that carefully controlled direct drying need not contribute PAHs to refined oils and fats. PMID:1806403

Dennis, M J; Massey, R C; Cripps, G; Venn, I; Howarth, N; Lee, G

12

Biodegradation of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

The intent of this review is to provide an outline of the microbial degradation of polycyclic aromatic hydrocarbons. A catabolically diverse microbial community, consisting of bacteria, fungi and algae, metabolizes aromatic compounds. Molecular oxygen is essential for the initial hydroxylation of polycyclic aromatic hydrocarbons by microorganisms. In contrast to bacteria, filamentous fungi use hydroxylation as a prelude to detoxification rather

Carl E. Cerniglia

1992-01-01

13

Nitro-polycyclic aromatic hydrocarbon contents of fumes from heated cooking oils and prevention of mutagenicity by catechin  

Microsoft Academic Search

According to earlier studies, fumes from cooking oils were found to be mutagenic and several polycyclic aromatic hydrocarbons (PAHs), (benzo(a)pyrene (B(a)P), benz(a)antracene (B(a)A), and dibenz(a,h)anthracene (DB(ah)A)) were identified. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and nitro-polycyclic aromatic hydrocarbons (NPAHs) were extracted from the samples and identified by HPLC chromatography. Extracts from three

Pei-Fen Wu; Tai-An Chiang; Li-Fang Wang; Chia-Shiung Chang; Ying-Chin Ko

1998-01-01

14

Aromaticity of benzenoid hydrocarbons  

SciTech Connect

In the past ten years a considerable advance has occurred in the chemist's ability to predict the aromatic character of cyclic conjugated molecules. Previous to 1969, most predictions of aromaticity had been based on Hueckel delocalization energies. In 1971, we introduced a method of obtaining resonance energies based on the Hueckel method which gave an excellent correlation between the calculated resonance energies and experimental properties for a wide range of cyclic conjugated systems. The major reason for our success was a change in the reference structure. No longer were isolated ethylenes used as the reference, instead, we used a reference which included terms for the ..pi.. contribution of both single and double bonds. In the case of benzene, the reference structure is the hypothetical molecule cyclohexatriene. The energy of the reference structure is obtained by summing the appropriate bond energy terms. These bond energy terms were obtained by analysis of the additivity of the Hueckel energies of acyclic polyenes. Hence, to calculate the resonance energy of any conjugated hydrocarbon, one needs only these bond energy terms and the Hueckel energy. Again we have chosen to divide these resonance energies by the number of ..pi.. electrons to give resonance energy per ..pi.. electron (REPE). The same set of compounds is listed in order of decreasing REPE. Experimental properties are in close agreement with REPE. Some compounds turn out to have near zero REPE and other negative REPE; these are termed nonaromatic and antiaromatic, respectively. In the case of benzenoid hydrocarbons, we have previously given REPE's for a number of these systems. In this work, we would like to expand this list and discuss a new correlation with some recent experimental results.

Hess, B.A. Jr.; Schaad, L.J.

1980-08-01

15

THE PHOTOTOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) continues to be interested in developing methods for the detection of polycyclic aromatic hydrocarbons (PAHS) in the environment. Polycyclic aromatic hydrocarbons (PAHS) are common contaminants in our environment. Being major product...

16

Combustion aerosol water content and its effect on polycyclic aromatic hydrocarbon reactivity  

Microsoft Academic Search

A linear relationship was observed between particle water uptake and relative humidity for aerosol samples collected on Teflon coated glass fiber filters. Gasoline soot and wood smoke sample weight increases were three to five times greater than diesel soot weight increases at comparable relative humidities. Lower limit estimates of wood smoke water content at 90% relative humidity were in the

Stephen R. Mcdow; Matti Vartiainen; Qingrui Sun; Yusen Hong; Yilin Yao; Richard M. Kamens

1995-01-01

17

Effects of polycyclic aromatic hydrocarbons exposure on antioxidant system activities and proline content in Kandelia candel  

Microsoft Academic Search

The antioxidant system effects of Kandelia candel were investigated under four different levels of PAH stress. The activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), the responses to the change of malondialdehyde (MDA) contents and the accumulation of proline in K. candel were determined. Our results suggested that the activities of SOD, CAT, POD increased

Hui Song; You-Shao Wang; Cui-Ci Sun; Mei-Lin Wu; Ya-Lan Peng; Chao Deng; Qian P. Li

2011-01-01

18

Nitro-polycyclic aromatic hydrocarbon contents of fumes from heated cooking oils and prevention of mutagenicity by catechin.  

PubMed

According to earlier studies, fumes from cooking oils were found to be mutagenic and several polycyclic aromatic hydrocarbons (PAHs), (benzo(a)pyrene (B(a)P), benz(a)antracene (B(a)A), and dibenz(a,h)anthracene (DB(ah)A)) were identified. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and nitro-polycyclic aromatic hydrocarbons (NPAHs) were extracted from the samples and identified by HPLC chromatography. Extracts from three cooking oil fumes contained 1-nitropyrene (1-NP) and 1,3-dinitropyrene (1,3-DNP). Concentrations of 1-NP and 1,3-DNP were 1.1 +/- 0.1 and 0.9 +/- 0.1 micrograms/m3 in fumes from lard oil, 2.9 +/- 0.3 and 3.4 +/- 0.2 micrograms/m3 in soybean oil, 1.5 +/- 0.1 and 0.4 +/- 0.1 micrograms/m3 in peanut oil, respectively. The preventive effect of three natural antioxidants (gamma-tocopherol (TOC), lecithin (LEC), and catechin (CAT)) for the reduction of mutagenicity and amounts of PAHs and NPAHs of fumes from cooking oils were evaluated. Mutagenicity of cooking oil fumes occurred, and the concentration of B(a)P were significantly reduced (p < 0.05), by adding CAT into cooking oils before heating. B(a)A, DB(ah)A, and two NPAHs were not detected when the concentration of CAT was 500 ppm in all three cooking oil fumes. These results indicate that fumes of cooking oils contained PAHs and NPAHs that may be a risk factor for lung cancer among cooks and the carcinogens could be reduced by adding the natural antioxidant, catechin. PMID:9726003

Wu, P F; Chiang, T A; Wang, L F; Chang, C S; Ko, Y C

1998-07-17

19

Degradation of soil environment in the post-flooding area: content of polycyclic aromatic hydrocarbons (PAHs) and s-triazine herbicides.  

PubMed

Impacts of flooding on the soil environment with regard to soil pollution with polycyclic aromatic hydrocarbons and s-triazine (cyanazine, simazine, atriazine, propazine, prometryn) herbicides have been evaluated. No clear differences in the sum of the PAHs content were observed in the present studies. Only changes in the levels of individual PAHs were noted. In soils covered with flooding both at a depth of 0-20 and 20-40 high molecular weight PAHs were predominant (especially mutagenic and carcinogenic 5-rings PAHs) whereas in non-flooded areas, 2- and 3-rings PAHs constituted over 80%. In the case of s-triazine herbicides, no influence of flooding on the changes in their content in agriculturally used soils was noted. On the other hand, clearly lower levels of cyanazine, simazine and atriazine were not in the flooded forest soil as compared to the non-flooded forest soil. PMID:14649710

Baran, Stanis?aw; Oleszczuk, Patryk; Baranowska, Ewa

2003-11-01

20

Shallow sublittoral meiofauna communities and sediment polycyclic aromatic hydrocarbons (PAHs) content on the Galician coast (NW Spain), six months after the Prestige oil spill.  

PubMed

The aim of this work was to detect the impact of Prestige oil spill on meiobenthic community structure at higher levels of taxonomic aggregation. In addition, the relationship between sediment individual polycyclic aromatic hydrocarbon (PAH) concentration and meiofauna community structure was investigated. Six months after the Prestige oil spill, meiobenthos community and sediment PAHs content from seven shallow subtidal localities along the Galician coast were studied. Two sites presented differences in community structure, characterized by high densities of nematodes, gastrotrichs and turbellarians, and low densities of copepods. Chrysene and triphenylene were only found at these two disturbed sites and could be responsible for differences of meiobenthos community structure. However, differences in community structure of sites could be linked with sedimentary parameters, and discrimination between the effect of PAHs and sedimentary parameters was impossible due to the lack of baseline studies on meiobenthos and PAHs contents in this area. PMID:19091356

Veiga, P; Rubal, M; Besteiro, C

2008-12-16

21

Polycyclic aromatic hydrocarbons in foundries.  

PubMed

Air and dust samples from iron foundries were analyzed for polycyclic aromatic hydrocarbons (PAH) by glass capillary gas chromatography, mass spectrometry, and thin-layer chromatography. Fifty compounds were identified as PAH, among them known carcinogens and cocarcinogens. Benzo[a]pyrene (B[a]P) was measured quantitatively. The results were grouped according to the types of organic additives in the molding sand. The B[a]P concentrations were highest in foundries using coal tar pitch and in the work phases of shake-out, casting, and molding. In the Ames assay the dust samples showed mutagenic activity, but in most cases lower than that calculated from the concentration of B[a]P. It is suggested that B[a]P can be used as a hygienic marker in branches of industry with PAH problems. PMID:7463509

Schimberg, R W; Pfäffli, P; Tossavainen, A

22

PROTONATED POLYCYCLIC AROMATIC HYDROCARBONS REVISITED  

SciTech Connect

We reconsider the contribution that singly protonated polycyclic aromatic hydrocarbons (PAHs; HPAH{sup +}s) might make to the Class A component of the 6.2 {mu}m interstellar emission feature in light of the recent experimental measurements of protonated naphthalene and coronene. Our calculations on the small HPAH{sup +}s have a band near 6.2 {mu}m, as found in experiment. While the larger HPAH{sup +}s still have emission near 6.2 {mu}m, the much larger intensity of the band near 6.3 {mu}m overwhelms the weaker band at 6.2 {mu}m, so that the 6.2 {mu}m band is barely visible. Since the large PAHs are more representative of those in the interstellar medium, our work suggests that large HPAH{sup +}s cannot be major contributors to the observed emission at 6.2 {mu}m (i.e., Class A species). Saturating large PAH cations with hydrogen atoms retains the 6.2 {mu}m Class A band position, but the rest of the spectrum is inconsistent with observed spectra.

Ricca, Alessandra [Carl Sagan Center, SETI Institute, 189 N. Bernardo Ave., Suite 100, Mountain View, CA 94043 (United States); Bauschlicher, Charles W. Jr [Entry Systems and Technology Division, Mail Stop 230-3, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Allamandola, Louis J., E-mail: Alessandra.Ricca-1@nasa.gov, E-mail: Charles.W.Bauschlicher@nasa.gov [Space Science Division, Mail Stop 245-6, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2011-02-01

23

Comparison of Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Airborne and Automobile Exhaust Particulates  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) and nitropolycyclic aromatic hydrocarbons (NPAH) in airborne particulates collected simultaneously at downtown and suburban sites and in exhaust particulates from diesel and gasoline engine vehicles were determined. The mean concentrations of all compounds in the atmosphere were lower at the suburban site. The differences between the two sites were smaller in airborne particulates than in the

Kazuichi Hayakawa; Tsuyoshi Murahashi; Kazuhiko Akutsu; Tetsuo Kanda; Ning Tang; Hitoshi Kakimoto; Akira Toriba; Ryoichi Kizu

2000-01-01

24

Adsorption and absorption of polycyclic aromatic hydrocarbons to rice roots  

Microsoft Academic Search

Rice roots and surrounding air, soil and water samples were collected for polycyclic aromatic hydrocarbon (PAH) analysis. The rice roots were separated into lateral roots and nodal roots, and the PAH concentration in the former was found to be higher than that in the latter. In addition, root physiological characteristics including root biotic mass, root lipid content and specific surface

X. C. Jiao; F. L. Xu; R. Dawson; S. H. Chen; S. Tao

2007-01-01

25

Polycyclic aromatic hydrocarbon contamination in the Italian diet  

Microsoft Academic Search

The content of total and carcinogenic polycyclic aromatic hydrocarbons (PAHs) in Italian foods was measured. The highest levels of PAHs were found in pizza baked in wood?burning ovens and barbecued beef and pork. Relatively high levels were also found in beet greens and squash, apples and bread, fried beef, pork and rabbit, cured meats and chocolate. Conversely low levels were

M. Lodovici; P. Dolara; C. Casalini; S. Ciappellano; G. Testolin

1995-01-01

26

Procedure for and results of simultaneous determination of aromatic hydrocarbons and fatty acid methyl esters in diesel fuels by high performance liquid chromatography  

Microsoft Academic Search

The content of aromatic hydrocarbons in diesel fuels is regulated by appropriate standards, and a further reduction in the allowed concentration of these hazardous substances in these fuels is expected. The content of aromatic hydrocarbons in diesel fuels is most often determined using standard methods EN-12916 or ASTM D-6591. The content of polycyclic aromatic hydrocarbons (PAHs) is determined from a

M. Kami?ski; E. Gilgenast; A. Przyjazny; G. Romanik

2006-01-01

27

Polycyclic aromatic hydrocarbons in stellar medium  

Microsoft Academic Search

Polycyclic Aromatic Hydrocarbons (PAHs) are an important com- ponent of the Interstellar Medium (ISM). They are being used as probes for understanding of process and conditions of different astrophysical environments. The understanding of their IR spectra and its variations with PAH size and ionization state is useful in characterizing the ISM. Spectral features of model graphene sheets and also that

Shantanu Rastogi

2005-01-01

28

Polycyclic Aromatic Hydrocarbon Far-infrared Spectroscopy  

Microsoft Academic Search

The far-IR characteristics of astrophysically relevant polycyclic aromatic hydrocarbons (PAHs) averaging in size around 100 carbon atoms have been studied using the theoretical spectra in the NASA Ames PAH IR Spectroscopic Database. These spectra were calculated using density functional theory. Selections of PAH species are made, grouped together by common characteristics or trends, such as size, shape, charge, and composition,

C. Boersma; C. W. Bauschlicher Jr.; A. Ricca; A. L. Mattioda; E. Peeters; A. G. G. M. Tielens; L. J. Allamandola

2011-01-01

29

Polycyclic aromatic hydrocarbons: environmental pollution and bioremediation  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed and relocated in the environment as a result of the incomplete combustion of organic matter. Many PAHs and their epoxides are highly toxic, mutagenic and\\/or carcinogenic to microorganisms as well as to higher systems including humans. Although various physicochemical methods have been used to remove these compounds from our environment, they have many

Sudip K Samanta; Om V Singh; Rakesh K Jain

2002-01-01

30

Liquid electrostatic developers containing aromatic hydrocarbons  

Microsoft Academic Search

A liquid electrostatic developer is described having improved charging characteristics consisting essentially of nonpolar liquid having a Kauri-butanol value of less than 30, thermoplastic resin particles substantially nonsoluble in nonpolar liquid and aromatic hydrocarbon at ambient temperature and having an average by area particle size of less than 10 is contained inm, nonpolar liquid soluble ionic or zwitterionic compound, and

1987-01-01

31

Analysis of nitrated polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Many nitrated polycyclic aromatic hydrocarbons (NPAH) that are present in low concentrations in the environment and in emission\\u000a sources have been shown to be mutagenic and\\/or carcinogenic. This paper reviews the current methods of analysis of these compounds\\u000a with the emphasis on NPAH measurements in ambient particulate matter samples.

Barbara Zielinska; Shar Samy

2006-01-01

32

Dihydrodiol dehydrogenase and polycyclic aromatic hydrocarbon metabolism  

SciTech Connect

Carcinogenic activation of polycyclic aromatic hydrocarbons by microsomal monoxygenases proceeds through trans-dihydrodiol metabolites to diol-epoxide ultimate carcinogens. This thesis directly investigated the role of dihydrodiol dehydrogenase, a cytosolic NAD(P)-linked oxidoreductase, in the detoxification of polycyclic aromatic trans-dihydrodiols. A wide variety of non-K-region trans-dihydrodiols were synthesized and shown to be substrates for the homogeneous rat liver dehydrogenase, including several potent proximate carcinogens derived from 7,12-dimethylbenz(a)anthracene, 5-methylchrysene, and benzo(a)pyrene. Since microsomal activation of polycyclic aromatic hydrocarbons is highly stereospecific, the stereochemical course of enzymatic trans-dihydrodiol oxidation was monitored using circular dichroism spectropolarimetry. The major product formed from the dehydrogenase-catalyzed oxidation of the trans-1,2-dihydrodiol of naphthalene was characterized using UV, IR, NMR, and mass spectroscopy, and appears to be 4-hydroxy-1,2-naphthoquinone. Mass spectral analysis suggests that an analogous hydroxylated o-quinone is formed as the major product of benzo(a)pyrene-7,8-dihydrodiol oxidation. Enzymatic oxidation of trans-dihydrodiols was shown to be potently inhibited by all of the major classes of the nonsteroidal antiinflammatory drugs. Enhancement of trans-dihydrodiol proximate carcinogen oxidation may protect against possible adverse effects of the aspirin-like drugs, and help maintain the balance between activation and detoxification of polycyclic aromatic hydrocarbons.

Smithgall, T.E.

1986-01-01

33

Mineralization of polycyclic and n-heterocyclic aromatic compounds in hydrocarbon-contaminated soils  

Microsoft Academic Search

The comparative mineralization of eight polycyclic aromatic compounds in five soils collected from an abandoned coal tar refinery in eastern Ohio was determined. The soils showed differences only in total extractable hydrocarbon content of the soil chemical characteristics measured. The compounds studied included five polycyclic aromatic hydrocarbons (phenanthrene, anthracene, pyrene, and carcinogenic benz[a]anthracene and benzo[a]pyrene) and three N-heterocyclic aromatics (9H-carbazole,

Robert J. Grosser; David Warshawsky; J. Robie Vestal

1995-01-01

34

Analysis of the polycyclic aromatic hydrocarbon content of petrol and diesel engine lubricating oils and determination of DNA adducts in topically treated mice by 32P-postlabelling.  

PubMed

Engine lubricating oils are known to accumulate carcinogenic polycyclic aromatic hydrocarbons (PAHs) during engine running. Oils from nine petrol-powered and 11 diesel-powered vehicles, in addition to samples of unused oil, were analysed for PAH content and ability to form DNA adducts when applied topically to mouse skin. The levels of 19 PAHs, determined by GC, were in total, approximately 22 times higher in used oils from petrol engines than in oils from diesel engines. Male Parkes mice were treated with 50 microliters of oil daily for 4 days before they were killed and DNA isolated from skin and lung tissue. DNA samples were analysed by nuclease P1-enhanced 32P-postlabelling. Used oils from both diesel and petrol engines showed several adduct spots on PEI-cellulose plates at total adduct levels of up to 0.57 fmol/microgram DNA [approximately 60 times greater than in experiments with samples of unused oil in which adduct levels (0.01-0.02 fmol adducts/microgram DNA) were close to the limit of detection]. Higher adduct levels were generally formed by petrol engine oils than by diesel engine oils. Lung DNA contained similar total adduct levels to those in skin although the adduct maps were less complex. Total adduct levels correlated with extent of oil use in the engine, the total PAH concentration in oils and with the concentrations of certain individual PAHs present in the oils. An adduct spot that co-eluted with that of the major benzo[a]pyrene-DNA adduct accounted for 9-26% of the total adducts in skin DNA, and approximately 8% of the adducts in lung DNA, of mice treated with petrol engine oils. A major, and as yet unidentified, adduct spot comprised up to 30% of the total adducts in skin DNA, and up to 89% of the total adducts in lung DNA, of these animals. PMID:2225336

Carmichael, P L; Jacob, J; Grimmer, G; Phillips, D H

1990-11-01

35

Black tattoo inks induce reactive oxygen species production correlating with aggregation of pigment nanoparticles and product brand but not with the polycyclic aromatic hydrocarbon content.  

PubMed

Black tattoo inks are composed of carbon nanoparticles, additives and water and may contain polycyclic aromatic hydrocarbons (PAHs). We aimed to clarify whether reactive oxygen species (ROS) induced by black inks in vitro is related to pigment chemistry, physico-chemical properties of the ink particles and the content of chemical additives and contaminants including PAHs. The study included nine brands of tattoo inks of six colours each (black, red, yellow, blue, green and white) and two additional black inks of different brands (n = 56). The ROS formation potential was determined by the dichlorofluorescein (DCFH) assay. A semiquantitative method was developed for screening extractable organic compounds in tattoo ink based on gas chromatography-mass spectrometry (GC-MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Two black inks produced high amounts of ROS. Peroxyl radicals accounted for up to 72% of the free radicals generated, whereas hydroxyl radicals and H?O? accounted for <14% and 16%, respectively. The same two inks aggregated strongly in water in contrast to the other black inks. They did not exhibit any shared pattern in PAHs and other organic substances. Aggregation was exclusively shared by all ink colours belonging to the same two brands. Ten of 11 black inks had PAH concentrations exceeding the European Council's recommended level, and all 11 exceeded the recommended level for benzo(a)pyrene. It is a new finding that aggregation of tattoo pigment particles correlates with ROS production and brand, independently of chemical composition including PAHs. ROS is hypothesized to be implicated in minor clinical symptoms. PMID:23800057

Høgsberg, Trine; Jacobsen, Nicklas Raun; Clausen, Per Axel; Serup, Jørgen

2013-07-01

36

Origins of polycyclic aromatic hydrocarbons in estuarine sediments  

Microsoft Academic Search

In order to determine the origin of polycyclic aromatic hydrocarbons (PAHs) in sediments from Narragansett Bay, Rhode Island, the PAH assemblages from the sediments and from possible origin materials were analyzed by gas Chromatographic and gas chromatographic-mass spectrometric techniques. Analyses included determinations of: 1. (1) the relative content of non-alkylated PAH parent molecules i.e. parent compound distributions (PCDs); 2. (2)

James L. Lake; Curtis Norwood; Crandall Dimock; Robert Bowen

1979-01-01

37

Carbon fibers from aromatic hydrocarbons  

SciTech Connect

Carbon filter is widely used as a lightweight and high-strength material for composite structures. Its uses are expected to expand in the next century. Currently the best precursor for making these fibers is polyacrylonitrile (PAN). This is a relatively expensive feedstock. Carbon fibers also have been made starting with so-called mesophase pitch fractions derived from low-cost hydrocarbons such as petroleum residuum. But these fibers suffer from low mechanical strength. In the past few years, significant advances have been made in understanding the mechanism of formation of mesophase pitch, which may lead to improved performance for carbon fibers and other specialty carbons. This article introduces such advances, based principally on the authors` recent results.

Mochida, Isao; Yoon, S.H.; Korai, Yozo; Kanno, Koichi; Sakai, Yukio; Komatsu, Makoto [Kyushu Univ. (Japan)

1995-02-01

38

Polycyclic aromatic hydrocarbons in the diet  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs), of which benzo[a]pyrene is the most commonly studied and measured, are formed by the incomplete combustion of organic matter. They are widely distributed in the environment and human exposure to them is unavoidable. A number of them, such as benzo[a]pyrene, are carcinogenic and mutagenic, and they are widely believed to make a substantial contribution to the

David H Phillips

1999-01-01

39

Detoxification of polycyclic aromatic hydrocarbons by fungi  

Microsoft Academic Search

Summary The polycyclic aromatic hydrocarbons (PAHs) are a group of hazardous environmental pollutants, many of which are acutely toxic, mutagenic, or carcinogenic. A diverse group of fungi, includingAspergillus ochraceus, Cunninghamella elegans, Phanerochaete chrysosporium, Saccharomyces cerevisiae, andSyncephalastrum racemosum, have the ability to oxidize PAHs. The PAHs anthracene, benz[a]anthracene, benzo[a]pyrene, fluoranthene, fluorene, naphthalene, phenanthrene, and pyrene, as well as several methyl-, nitro-,

John B. Sutherland

1992-01-01

40

Analysis of nitrated polynuclear aromatic hydrocarbons  

Microsoft Academic Search

A derivatization-gas chromatography\\/electron capture detector (GC\\/ECD) method has been developed for the measurement of trace nitrated polynuclear aromatic hydrocarbons (NPAHs) in air. The method involves first the derivatization of parent nitro-PAHs to their corresponding fluorinated derivatives, followed by GC\\/ECD analysis. The sensitivity of the method is an order of magnitude higher than those of direct GC\\/ECD analysis of NPAHs themselves.

Xu Jinhui; Frank S. C Lee

2001-01-01

41

Polycyclic Aromatic Hydrocarbons (by Ronald G. Harvey)  

Microsoft Academic Search

Ronald G. Harvey. Wiley, VCH: New York, 1997. 667 pp. ISBN 0-471-18608-2. $125. This text is a timely and welcome addition to the ever-growing literature on polycyclic aromatic hydrocarbon (PAH) chemistry and an essential addition to the chemist's library. It is the most comprehensive and complete account of the synthesis and chemical properties of polyarenes to date. The author has

C. F. Murray

1998-01-01

42

Adsorption of Polycyclic Aromatic Hydrocarbon Compounds onto Soil and Transport of Naphthalene in Unsaturated Porous Media.  

National Technical Information Service (NTIS)

This study evaluated procedures for estimating adsorption of polycyclic aromatic hydrocarbons (PAH) onto soil from knowledge of soil organic carbon content and physico-chemical properties or structural characteristics of PAH. The study also entailed an ex...

D. A. Dzombak J. K. Fu R. G. Luthy

1983-01-01

43

Processes for the separation of aromatic hydrocarbons from a hydrocarbon mixture  

SciTech Connect

A process is described for separating aromatic hydrocarbons from a hydrocarbon feed stream containing aromatic and nonaromatic hydrocarbons, comprising; (a) passing the feed stream which is at least partially vaporized to an extractive distillation column having a reboiler associated therewith maintained at extractive distillation conditions effective to separate aromatic from nonaromatic hydrocarbons and contacting the feed stream within said distillation column with a lean solvent stream comprising an aromatic selective solvent and a reflux hydrocarbon stream comprising non-aromatic hydrocarbons; (b) withdrawing a raffinate stream comprising non-aromatic hydrocarbons from an overhead section of said distillation column; (c) withdrawing a rich solvent stream comprising the aromatic selective solvent, aromatic hydrocarbons and nonaromatic hydrocarbons from a bottom section of said distillation column; and reboiling a portion of said rich solvent stream to provide a reboiled rich solvent and returning said reboiled rich solvent to said bottom section of said distillation column; (d) passing the rich solvent stream to a stripping column maintained at stripping conditions effective to separate the aromatic selective solvent from the aromatic hydrocarbons and contacting the rich solvent stream within said stripping column with stripping stream; (e) withdrawing a stripper overhead stream comprising water and non-aromatic hydrocarbons from an overhead section of said stripping column; (f) withdrawing a stripper bottoms stream comprising the lean solvent stream from a bottom section of said stripping column; and (g) withdrawing a side-cut stream comprising aromatic hydrocarbons from an intermediate section of said stripping column.

Vidueira, J.A.

1993-07-06

44

Degradation of polycyclic aromatic hydrocarbons adsorbed over chrysotile asbestos  

SciTech Connect

A process is described for degrading polycyclic aromatic hydrocarbons adsorbed over chrysotile asbestos fibers which comprises oxidizing at low temperature in the presence of moisture with ozone a mass of polycyclic aromatic hydrocarbons adsorbed on chrysotile asbestos fibers, while the hydrocarbons are degraded mainly to carbon dioxide and the resulting chrysotile asbestos is recovered.

Lalancatte, J.M.; Menard, H.

1986-09-16

45

QUANTITATIVE ANALYSIS OF POLYNUCLEAR AROMATIC HYDROCARBONS IN LIQUID FUELS  

EPA Science Inventory

Polynuclear aromatic hydrocarbons (PNAs), formed in combustion processes with liquid hydrocarbon fuels, contribute to mobile source exhaust emissions. Because correlation between PNA levels in automobile exhaust and pre-existent PNAs in fuel has been demonstrated in previous work...

46

Polycyclic aromatic hydrocarbons in stellar medium  

NASA Astrophysics Data System (ADS)

Polycyclic Aromatic Hydrocarbons (PAHs) are an important com- ponent of the Interstellar Medium (ISM). They are being used as probes for understanding of process and conditions of different astrophysical environments. The understanding of their IR spectra and its variations with PAH size and ionization state is useful in characterizing the ISM. Spectral features of model graphene sheets and also that of smaller PAH molecules are reported. The variation of intensity with charge state of the molecule shows that cations give a better correlation with observations. The relationship between changes in charge distribution with intensity changes upon ionization has been probed.

Rastogi, Shantanu

2005-06-01

47

Bioremediation technologies for polycyclic aromatic hydrocarbon compounds  

SciTech Connect

Polycyclic aromatic hydrocarbon compounds (PAHs) are common and challenging contaminants that affect soil and sediments. Methods for treating PAHs have undergone change and refinement in the recent past, and this volume presents the latest trends in PAH remediation theory and practice. The papers in this volume cover topics ranging from the remediation of manufactured gas plant (MGP) sites to the remediation of sediments. The papers present lab and field studies, characterization studies, comparison studies, and descriptions of technologies ranging from composting to thermally enhanced bioremediation to fungal technologies and other innovative approaches.

Alleman, B.C.; Leeson, A.

1999-01-01

48

Bioremediation technologies for polycyclic aromatic hydrocarbon compounds  

SciTech Connect

Polycyclic aromatic hydrocarbon compounds (PAHs) are common and challenging contaminants that affect soil and sediments. Methods for treating PAHs have undergone change and refinement in the recent past, and this volume presents the latest trends in PAH remediation theory and practice. The papers in this volume cover topics ranging from the remediation of manufactured gas plant (MGP) sites to the remediation of sediments. The papers present lab and field studies, characterization studies, comparison studies, and descriptions of technologies ranging from composting to thermally enhanced bioremediation to fungal technologies and other innovative approaches.

Alleman, B.C.; Leeson, A. [eds.

1999-10-01

49

Bioremediation technologies for polycyclic aromatic hydrocarbon compounds  

SciTech Connect

Polycyclic aromatic hydrocarbon compounds (PAHs) are common and challenging contaminants that affect soil and sediments. Methods for treating PAHs have undergone change and refinement in the recent past, and this volume presents the latest trends in PAH remediation theory and practice. The papers in this volume cover topics ranging from the remediation of manufactured gas plant (MGP) sites to the remediation of sediments. The papers present lab and field studies, characterization studies, comparison studies, and descriptions of technologies ranging from composting to thermally enhanced bioremediation to fungal technologies and other innovative approaches.

Alleman, B.C.; Leeson, A.

1999-11-01

50

Recent Changes in Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) and Nitropolycyclic Aromatic Hydrocarbons (NPAHs) in Shenyang, China  

Microsoft Academic Search

Airborne particulates were collected in three size fractions by using Anderson low-volume air samplers in Shenyang, China, in winter and summer in 2007. Compared with data obtained in 2001 at the same sites, the total concentrations of nine polycyclic aromatic hydrocarbons (PAHs) in winter decreased by 67% at one site and decreased by 40% at the other site, while the

Ning Tang; Takahiro Tokuda; Akihiko Izzaki; Kenji Tamura; Ruonan Ji; Xuemei Zhang; Lijun Dong; Takayuki Kameda; Akira Toriba; Kazuichi Hayakawa

2011-01-01

51

AROMATIC AND POLYCYCLIC AROMATIC HYDROCARBON FORMATION IN A LAMINAR PREMIXED N-BUTANE FLAME. (R825412)  

EPA Science Inventory

Abstract Experimental and detailed chemical kinetic modeling work has been performed to investigate aromatic and polycyclic aromatic hydrocarbon (PAH) formation pathways in a premixed, rich, sooting, n -butane¯oxygen¯argon burner s...

52

Biomarkers of Exposure to Polycyclic Aromatic Hydrocarbons and Related Compounds  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) are widespread carcinogenic compounds that arise from occupational, environmental and dietary sources. The metabolites of PAHs and NPAHs in biological fluids have been investigated as potential biomarkers for assessing human exposure to them, and, particularly, urinary metabolites are the excelle nt candidates due to the non-invasiveness and convenience of collecting the

Akira Toriba; Kazuichi Hayakawa

2007-01-01

53

Laboratory Investigation of Organic Aerosol Formation from Aromatic Hydrocarbons  

SciTech Connect

Our work for this DOE funded project includes: (1) measurements of the kinetics and mechanism of the gas-phase oxidation reactions of the aromatic hydrocarbons initiated by OH; (2) measurements of aerosol formation from the aromatic hydrocarbons; and (3) theoretical studies to elucidate the OH-toluene reaction mechanism using quantum-chemical and rate theories.

Luisa T. Molina; Mario J. Molina; Renyi Zhang

2006-08-23

54

Thermodynamics of aliphatic and aromatic hydrocarbons in water  

Microsoft Academic Search

Makhatadze and Privalov have analyzed the thermodynamics of transfer of aliphatic and aromatic hydrocarbons from the gas phase into water. Finding that the hydration free energy of aliphatic and aromatic hydrocarbons have different signs, they conclude that the mechanism causing hydrophobicity of these solutes is of a different nature. Here, we offer an alternative analysis of the dissolution of these

Miguel Costas; Bengt Kronberg

1998-01-01

55

Estimating adsorption of polycyclic aromatic hydrocarbons on soils  

SciTech Connect

This paper presents a synthesis of information available on the adsorption of polycyclic aromatic hydrocarbons (PAH) in water/soil systems. Included is an analysis of how limited adsorption data for PAH on soils may be used in conjunction with PAH molecular characteristics to predict adsorption properties for a wide range of PAH and soils. Also presented is an evaluation of procedures that enable prediction of adsorption characteristics of PAH on soils based on soil organic carbon content and physical chemical or structural characteristics of the particular compound. 60 references, 4 figures, 4 tables.

Dzombak, D.A.; Luthy, R.G.

1984-05-01

56

Considerations of Atmospheric Behaviors of Polycyclic Aromatic Hydrocarbons, Nitropolycyclic Aromatic Hydrocarbons and Inorganic Pollutants Based on Their Interrelationships  

Microsoft Academic Search

Airborne particulates were collected during the same periods in downtown Kanazawa, Sapporo and Tokyo and polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) were determined together with several heavy metal elements and water-soluble inorganic ions. The mean concentrations of metal elements and inorganic ions were the highest in Tokyo, followed by Sapporo and the lowest in Kanazawa both in

Hitoshi Kakimoto; Hitoshi Yokoe; Yutaka Matsumoto; Shigekatsu Sakai; Fumio Kanoh; Tsuyoshi Murahashi; Kazuhiko Akutsu; Akira Toriba; Ryoichi Kizu; Kazuichi Hayakawad

2001-01-01

57

Polycyclic aromatic hydrocarbon molecules of astrophysical interest  

NASA Astrophysics Data System (ADS)

This research seeks to provide a more rigorous experimental foundation for the hypothesis of polycyclic aromatic hydrocarbon (PAH) molecules being a prominent constituent of the interstellar medium (ISM) by evaluating the roles they may have in contributing to the interstellar extinction curve, the diffuse interstellar absorption bands (DIB's), and the unidentified infrared (UIR) emissions. As an interstellar hydrocarbon component, complex molecules such as PAH's need also to be considered in scenarios leading to the presence of hydrocarbons in the solar nebula during formation of the solar system. The hypothesis that PAHs are responsible for the cosmic UIR bands is primarily a result of the general correlation between the UIR features and the laboratory absorption spectra of PAH's. A serious problem has been that the strong absorption features in the near-UV are not seen in the interstellar extinction curve. The first part of this research has been aimed toward removing this conflict. The experiment involved electronic absorption measurements on both neutral and cationic forms of PAH species. The pronounced decrease in the strength of the near-UV absorption bands of the neutral species upon ionization by gamma radiation indicates that PAH's, which are expected to be ionized in the general ISM and still to produce the UIR emissions, would not exhibit near-UV features from the bluest DIB at 4428 A to the UV extinction bump at 2176 A. In considering the possible contribution of interstellar PAH's to the hydrocarbon component in carbonaceous chondrites and interplanetary dust particles (IDP's), the mid-IR spectrum of a film-like deposit produced through plasma discharge of a gaseous mixture of hydrogen and the simplest PAH, naphthalene, has been obtained. This experiment that has evidently resulted in the synthesis of a laboratory analog for the hydrocarbon component of the alkane-predominant Murchison meteorite suggests that the hydrocarbon material originated as PAH's formed in the atmospheres of carbon stars during their later stages of stellar evolution. It also implies that the pathway from those formation sites, to the interstellar space where they become enriched with deuterium in dark clouds, and to incorporation into the parent bodies of meorites and IDPs probably involved hydrogenation of PAH's into alkanes in plasma of the solar nebula or in H II regions prior to the solar nebula.

Lee, Wei

58

Analysis of nitrated polynuclear aromatic hydrocarbons.  

PubMed

A derivatization-gas chromatography/electron capture detector (GC/ECD) method has been developed for the measurement of trace nitrated polynuclear aromatic hydrocarbons (NPAHs) in air. The method involves first the derivatization of parent nitro-PAHs to their corresponding fluorinated derivatives, followed by GC/ECD analysis. The sensitivity of the method is an order of magnitude higher than those of direct GC/ECD analysis of NPAHs themselves. The method is simple and robust and thus ideally suited for the routine monitoring of NPAHs in air samples. The sensitivity and reproducibility of GC/negative ion chemical ionization MS (NICIMS) for the measurement of NPAHs after derivatization has been evaluated. The method has sensitivity comparable to GC/ECD, but is less reproducible in quantification. The method is therefore suitable for method validation and NPAHs peak confirmation rather than routine operations. PMID:11100923

Jinhui, X; Lee, F S

2001-01-01

59

Coumarin, Naphthalene, and Additional Polycyclic Aromatic Hydrocarbons  

NSDL National Science Digital Library

The featured molecules this month are drawn from two papers. The first, "One-Pot Synthesis of 7-Hydroxy-3-carboxycoumarin in Water", is a Green Chemistry feature by Fringuelli, Piermatti, and Pizzo. The three-dimensional versions of the molecules in the synthesis of the coumarin derivative are directly tied to the reaction scheme included in the paper, opening the possibility of showing large numbers of complex synthetic pathways in this manner.The second paper is "Determining the Carbon-Carbon Distance in an Organic Molecule with a Ruler" by Simoni, Tubino, and Ricchi. This article describes an experiment to determine the size of a naphthalene molecule, using an extension of classic experiments for determining molecular size and Avogadro's number. While the structure of naphthalene will come as no surprise to most students, the molecule collection also includes additional polycyclic aromatic hydrocarbons (PAHs) that can be used to introduce students to the environmental and health issues related to these molecules.

60

Ions colliding with polycyclic aromatic hydrocarbon clusters  

NASA Astrophysics Data System (ADS)

We have measured the ionization and fragmentation of polycyclic aromatic hydrocarbon (PAH) molecules and their clusters. We find that PAH clusters containing up to roughly 100 individual molecules fragment strongly following collisions with keV ions in low or high charge states (q). For both types of collisions, singly charged PAH molecules are found to be the dominant products but for very different reasons. A high-q ion projectile charge leads to strong multiple ionization of the PAH clusters and subsequent Coulomb explosions. A low-q ion projectile charge often leads to single ionization but stronger internal heating and long evaporation sequences with a singly charged PAH monomer as the end product. We have developed a Monte Carlo method for collision-induced heating of PAH clusters and present an evaporation model where the clusters cool slowly as most of the internal energies are stored in intramolecular vibrations and not in molecule-molecule vibrations.

Gatchell, M.; Zettergren, H.; Seitz, F.; Chen, T.; Alexander, J. D.; Stockett, M. H.; Schmidt, H. T.; ?awicki, A.; Rangama, J.; Rousseau, P.; Capron, M.; Maclot, S.; Maisonny, R.; Domaracka, A.; Adoui, L.; Méry, A.; Chesnel, J.-Y.; Manil, B.; Huber, B. A.; Cederquist, H.

2013-09-01

61

Polycyclic aromatic hydrocarbons: trends for bonding hydrogen.  

PubMed

Hydrogenation of carbonaceous materials is important within carbon-based electronics, hydrogen storage, and the catalytic formation of molecular hydrogen in space. This study presents a systematic investigation at the density functional theory level of the hydrogenation of all small closed-shell polycyclic aromatic hydrocarbons comprising up to four carbon hexagons plus pentacene, hexacene, and heptacene. Binding energies span from 0.43 to 2.70 eV. Two-fold coordinated carbon atoms are preferred as binding sites with binding energies from 1.06 to 2.70 eV. Analyzing the binding sites yields three different motifs each with a clear structural and electronic fingerprint explaining the ordering of the binding sites. PMID:23621608

Rasmussen, Jakob Arendt

2013-05-13

62

Superaromatic stabilization energy as a novel local aromaticity index for polycyclic aromatic hydrocarbons.  

PubMed

Superaromatic stabilization energy (SSE), previously proposed by us, can be used as a novel local aromaticity index for benzene rings in polycyclic aromatic hydrocarbons (PAHs). SSE can be interpreted as the first local aromaticity index explicitly related to all relevant circuits in a polycyclic ?-system, an origin of local aromaticity, being free of local aromaticity arising from adjacent six-site circuits. Therefore, this quantity is best suited for characterizing the electronic structure of large pericondensed PAHs and graphene nanoflakes. PMID:24028404

Aihara, Jun-Ichi; Makino, Masakazu; Sakamoto, Kenkichi

2013-09-30

63

Distribution of polycyclic aromatic hydrocarbons in agricultural soils in South Korea  

Microsoft Academic Search

The content and type of polycyclic aromatic hydrocarbons (PAH) in soils from paddy fields and upland areas in South Korea were determined using gas chromatography linked to mass spectrometry (GC–MS). The distribution map of total PAH content was obtained as a contour plot using a geographical information system. The overall distribution of PAH was found to be closely related to

J. J. Nam; B. H. Song; K. C. Eom; S. H. Lee; A. Smith

2003-01-01

64

Application of hydroxypropyl[?]cyclodextrin to evaluation of polycyclic aromatic hydrocarbon losses during sewage sludges composting  

Microsoft Academic Search

The aims of the present study were to test the application of the non-exhaustive extraction technique (NEET) with hydroxypropyl[?]cyclodextrin (HPCD) for the evaluation of the content of potentially bioavailable polycyclic aromatic hydrocarbon (PAH) fraction as well as the evaluation of changes in the content of this fraction during composting of municipal sewage sludges. A possibility to apply this method for

Patryk Oleszczuk

2007-01-01

65

DETERMINATION OF POLYNUCLEAR AROMATIC HYDROCARBONS IN INDUSTRIAL AND MUNICIPAL WASTEWATERS  

EPA Science Inventory

A method for the determination of 16 polynuclear aromatic hydrocarbons (PAH) in wastewater was developed. This method, based on the use of high performance liquid chromatography with ultraviolet and fluorescence detection, is readily suited for detection of condensed ring aromati...

66

POLYCYCLIC AROMATIC HYDROCARBON (PAH) EXPOSURE OF 257 PRESCHOOL CHILDREN  

EPA Science Inventory

We investigated the polycyclic aromatic hydrocarbon (PAH) exposure of 257 preschool children and their adult caregivers in their everyday environments. Participants were recruited randomly from eligible homes and daycare centers within six North Carolina (NC) and six Ohio (OH) c...

67

NATURAL BIOLOGICAL ATTENUATION OF AROMATIC HYDROCARBONS UNDER ANAEROBIC CONDITIONS  

EPA Science Inventory

There is little consistent difference in the calculated half-lives of aromatic hydrocarbons in different anaerobic environments, but methanogenic environments might be generally the least supportive of rapid biotransformation. Toluene was usually the most rapidly biotransformed...

68

ENGINEERED ANTIBODIES FOR MONITORING OF POLYNUCLEAR AROMATIC HYDROCARBONS  

EPA Science Inventory

The objective of this multidisciplinary project is to use molecular biological techniques to derive a set of antibodies with useful affinities and selectivities for recovery and detection of polynuclear aromatic hydrocarbons (PAHs) in environmental and biological samples. The lon...

69

POLYNUCLEAR AROMATIC HYDROCARBONS IN ESTUARINE AND NEARSHORE ENVIRONMENTS  

EPA Science Inventory

Polynuclear aromatic hydrocarbons (PNAH) are ubiquitous and are found in waters, soil, and bottom sediments throughout the world, although the concentrations are higher in industrialized locations. Interest in these compounds is generated by their carcinogenic and mutagenic prope...

70

Study of the Adsorption of Aromatic Hydrocarbons by Marine Sediments.  

National Technical Information Service (NTIS)

Three aromatic hydrocarbons--benzene, naphthalene, and phenanthrene--were rapidly and strongly adsorbed by intertidal sediments from Jakolof Bay, lower Cook Inlet. Adsorption of phenanthrene was more than twice that of naphthalene and benzene. Adsorption ...

S. M. Henrichs M. Luoma S. Smith

1997-01-01

71

BIODEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBONS BY PHANEROCHAETE CHRYSOSPORIUM  

EPA Science Inventory

The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHS) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. nalysis by capillary gas chromatography and high-performance liq...

72

Aromatics saturation process for diesel boiling-range hydrocarbons  

Microsoft Academic Search

This patent describes a process for the concomitant hydrogenation of aromatics and sulfur-bearing hydrocarbons in an aromatics- and sulfur-bearing hydrocarbon feedstock having substantially all of this components boiling in the range of abut 200°F to about 900°F. It comprises: contacting at a temperature between about 600°F. and abut 750°F and a pressure between about 650 psi and about 2500 psi

Bhan

1991-01-01

73

Polynuclear aromatic hydrocarbons in the water environment*  

PubMed Central

Many polynuclear aromatic hydrocarbons (PAH) are known to be carcinogenic to animals and probably to man. This review is concerned with carcinogenic and non-carcinogenic PAH in the water environment, with emphasis on 3,4-benzpyrene (BP) because it is ubiquitous, is one of the most potent of the carcinogenic PAH and has been widely studied. Although PAH are formed in combustion and other high-temperature processes, there is also evidence for their endogenous formation in plants, which may explain their ubiquity therein. Although the solubility of these compounds in pure water is very low, they may be solubilized by such materials as detergents, or they may otherwise occur in aqueous solution associated with or adsorbed on to a variety of colloidal materials or biota, and thereby be transported through the water environment. A notable characteristic of PAH is their sensitivity to light. PAH have been found in industrial and municipal waste effluents, and occur in soils, ground waters and surface waters, and their sediments and biota. With the exception of filtration or sorption by activated carbon, conventional water treatment processes do not efficiently remove them, and they have been found in domestic water supplies. Because of the ubiquity of PAH in the environment, it is impossible to prevent completely man's exposure to them; nevertheless their surveillance should be continued and their concentrations in the environment should be reduced where practicable.

Andelman, Julian B.; Suess, Michael J.

1970-01-01

74

Conversion process of aromatic hydrocarbon from low molecular paraffin hydrocarbon  

SciTech Connect

This patent describes a process for conversion of low molecular paraffin hydrocarbon to aromatic hydrocarbon which comprises bringing the low molecular paraffin hydrocarbons into contact with a metallo-silicate catalyst (Si/Me) wherein the atomic ratio of Si/Me is 25-3200, and Me is one selected from the group consisting of Al, Ga, Ti, Zr, Ge, La, Mn, Cr, Sc, V, Fe, W, Mo and Ni, which is impregnated or ion-exchanged with 0.25-1.5% by weight of platinum or gallium, based on the catalyst, or a gallium-silicate cataylst. The atomic ratio of Si/Ga is 20-3200. The catalyst is prepared by the following steps; a first step of preparing solutions of (A), (B), and (C), the (A) being an aqueous solution containing (a) a quaternary lower alkylammonium cation R, (b) an alkaline metal of sodium or potassium, and (c) an aqueous solution of a water soluble salt of a metal Me selected from the group consisting of Al, Ga, Ti, Zr, Ge, La, Mn, Cr, Sc, V, Fe, W, Mo and Ni; (B) an aqueous silicate solution, and (C) an aqueous solution of an ion modifier. Add the solution (A) and solution (B) to the solution (C) at a constant speed until a gelly mixture having a pH of around 10. Then grind the resulting gel mixture. Heat the gel mixture to a temperature of 150/sup 0/-190/sup 0/C at a constant speed followed by heating to 190/sup 0/-200/sup 0/C at a constant speed or an exponential speed to obtain a precourser synthetic metallosilicate having the following chemical composition in molar ratio: Si/Me: 25-3200 OH-SiO/sub 2/: 0.3-1.0 H/sub 2/O/SiO/sub 2/: 30-100 R/R+alkalimetal: 0.05-0.15 NaCl/H/sub 2/O: 0.01-0.06 wherein R is a quaternary alkylammonium cation, the alkali metal is sodium or potassium and Me is Al, Ga, Ti, Zr, Ge, La, Mn, Cr, Sc, V, Fe, W, Mo or Ni and fourth step of calcining the precourser.

Inui, T.

1987-11-03

75

Comparison of polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in airborne particulates collected in downtown and suburban Kanazawa, Japan  

Microsoft Academic Search

In this study, airborne particulates were collected at three sites, two in a downtown area and the other in a suburban area of Kanazawa, Japan in each season for 7 years. Two polycyclic aromatic hydrocarbons (PAHs), pyrene (Py) and benzo[a]pyrene (BaP) and four nitropolycyclic aromatic hydrocarbons (NPAHs), 1-nitropyrene (NP) and 1,3-, 1,6-, and 1,8-dinitropyrenes (DNP) were determined by high-performance liquid

Kazuichi Hayakawa; Ning Tang; Kazuhiko Akutsu; Tsuyoshi Murahashi; Hitoshi Kakimoto; Ryoichi Kizu; Akira Toriba

2002-01-01

76

Aliphatic and aromatic hydrocarbons in coastal caspian Sea sediments  

Microsoft Academic Search

This investigation represents the first extensive study of the spatial distribution and sources of aliphatic (n-alkanes and unresolved complex mixture of fossil hydrocarbons) and polycyclic aromatic hydrocarbons (PAHs) in coastal sediments from the Caspian Sea. PAH concentrations, n-alkanes and biomarker profiles all suggested that there was limited petrogenic contamination in the shallow North Caspian Sea sediments, which are coarse with

Imma Tolosa; Stephen de Mora; Mohammad Reza Sheikholeslami; Jean-Pierre Villeneuve; Jean Bartocci; Chantal Cattini

2004-01-01

77

Petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in Hong Kong marine sediments  

Microsoft Academic Search

A total of 20 surficial sediment samples, obtained from Hong Kong coastal waters, were analysed for petroleum hydrocarbons (PHCs) and a suite of 15 polycyclic aromatic hydrocarbons (PAHs). The results indicate that Hong Kong coastal sediments are often seriously polluted with petroleum related hydrocarbons. This is especially so in heavily urbanised or industrialized localities, such as Kowloon Bay (Victoria Harbour),

Gene J. Zheng; Bruce J. Richardson

1999-01-01

78

The biodegradation of aromatic hydrocarbons by bacteria  

Microsoft Academic Search

Aromatic compounds of both natural and man-made sources abound in the environment. The degradation of such chemicals is mainly accomplished by microorganisms. This review provides key background information but centres on recent developments in the bacterial degradation of selected man-made aromatic compounds. An aromatic compound can only be considered to be biodegraded if the ring undergoes cleavage, and this is

Mark R. Smith

1990-01-01

79

Hydrocarbon Analogues of Boron Clusters: Planarity, Aromaticity, and Antiaromaticity  

SciTech Connect

An interesting feature of elemental boron and boron compounds is the occurrence of highly symmetric icosahedral clusters. The rich chemistry of boron is also dominated by three-dimensional cage structures. Despite its proximity to carbon, elemental boron clusters have been scarcely studied experimentally and their structures and chemical bonding have not been fully elucidated. Here we report experimental and theoretical evidence that small boron clusters prefer planar structures and exhibit aromaticity and antiaromaticity according to the Hckel rules, akin to planar hydrocarbons. Aromatic boron clusters possess more circular shapes whereas antiaromatic boron clusters are elongated, analogous to structural distortions of antiaromatic hydrocarbons. The planar boron clusters are thus the only series of molecules other than the hydrocarbons to exhibit size-dependent aromatic and antiaromatic behavior and represent a new dimension of boron chemistry. The stable aromatic boron clusters may exhibit similar chemistries as that of benzene, such as forming sandwich-type metal compounds.

Zhai, Hua-Jin; Boggavarapu, Kiran; Li, Jun; Wang, Lai-Sheng

2003-12-01

80

The influence of baking fuel on residues of polycyclic aromatic hydrocarbons and heavy metals in bread  

Microsoft Academic Search

The influence of fuel type used to bake bread on the spectrum and concentrations of some polycyclic aromatic hydrocarbons and heavy metals in baked bread was assessed. Bread samples were collected from different bakeries operated by either electricity, solar, mazot or solid waste and their residue content of PAHs and heavy metals was assessed. The total concentration of PAHs detected

Mohamed Tawfic Ahmed; El-Sayed Abdel Hadi; S El Samahy; K Youssof

2000-01-01

81

Polycyclic aromatic hydrocarbon (PAH)-phase associations in Washington coastal sediment  

Microsoft Academic Search

Polycyclic aromatic (PAH) and aliphatic hydrocarbon compositions, organic carbon, nitrogen and lignin contents were determined in whole, unfractionated sediment from the Washington continental shelf and in discrete sediment fractions separated by particle size and density. At least 20 to 25% of perylene and PAH derived from pyrolytic processes and 50% of the retene measured in whole sediment are contained within

Fredrick G. Prahl; Roy Carpenter

1983-01-01

82

Effect of Temperature on the Distribution of Polycyclic Aromatic Hydrocarbons in Soil and Sediment  

Microsoft Academic Search

The knowledge of sorption-desorption processes of polycyclic aromatic hydrocarbons (PAHs) in natural solids is essential to predict the fate, transport, and environmental risks of these pollutants. In this study, the effect was investigated of temperature on the sorption-desorption of three PAHs (naphthalene, phenanthrene, and pyrene) in two natural solids with different organic carbon contents. In all cases, the sorption isotherms

Edgar HillEr

83

Polycyclic aromatic hydrocarbons in ash: Determination of total and leachable concentrations  

Microsoft Academic Search

Before wood ash can be used as a soil fertilizer, concentrations of environmentally hazardous compounds must be investigated. In this study, total and leachable concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in four ash samples and one green liquor sludge. The ash sample with the highest carbon content also contained high levels of PAHs; three of the ash

Anja Enell; Filippa Fuhrman; Lisa Lundin; Per Warfvinge; Gunnar Thelin

2008-01-01

84

Astrochemical studies of polycyclic aromatic hydrocarbons and fullerenes  

NASA Astrophysics Data System (ADS)

Microprobe laser-desorption, laser-ionization mass spectrometry (mL 2 MS) is used to measure the spatial and chemical distributions of polycyclic aromatic hydrocarbons (PAHs) and related carbonaceous compounds in a variety of real and laboratory-simulated extraterrestrial samples. The combination of this sensitive microanalytical technique with this interesting group of compounds provides novel information about the chemical history of the solar system, the potential for the formation of life on other worlds, and the rich chemistry that exists in interstellar space. This dissertation focuses first on properties of the mL 2 MS technique. Factors affecting its quantitative abilities were determined. It is also shown that mL 2 MS samples the free organic material in meteorites, rather than the macromolecular material. Additionally, mL 2 MS was modified to detect the fullerene molecule C 60 in toluene solutions but proved incapable of detecting aggregated C 60 . The focus of this thesis then turns to the analysis of laboratory simulations and field samples of astrochemical interest: (1) The spatial distribution and degree of alkylation of PAHs were measured in carbonaceous chondrites. The results suggest that meteoritic PAHs resulted from a common pool of compounds prior to meteoritic parent-body formation. These compounds may then have been separated chromatographically by parent-body aqueous exposure or lost by volatilization during thermal metamorphism. (2) C 60 was detected in samples from three terrestrial impact craters (Sudbury, Gardnos, and Ries) using surface-enhanced laser desorption/ionization. (3) Energetic processing of interstellar ice analogs by ultraviolet radiation or high-energy proton irradiation caused the addition of a variety of side groups to the PAH coronene, as detected by mL 2 MS. Formation of new C-C, C-O, and C-N bonds was observed. (4) Simulations of the atmospheric chemistry of Titan showed that PAHs and nitrogen-containing aromatics may be formed in this environment. The aromatic content and extent of aromatic nitrogen incorporation detected by mL 2 MS increased in tholins formed at lower pressures. (5) mL 2 MS and gas chromatography-mass spectrometry (GC-MS) analysis of Siberian hydrothermal samples revealed the presence of PAHs and aliphatic hydrocarbons, with abundance and distribution varying among the sampling sites. These compounds may be of abiotic or biologic origin.

Elsila, Jamie Elizabeth

85

Determination of low concentrations of aromatic hydrocarbons in multicomponent mixtures with iso-octane and n-heptane  

NASA Astrophysics Data System (ADS)

We have experimentally studied the absorption spectra of hydrocarbon mixtures based on n-heptane and isooctane with small (1%-2%) additions of aromatic hydrocarbons (benzene, toluene, xylene). The study was conducted in the region of the first overtones of the vibrational spectra for the hydrocarbon groups CH3, CH2, CH. We show that four-component modeling of the absorption spectrum of the hydrocarbon mixture and minimization of the deviation of the model spectrum from the experimental spectrum allow us to separately determine the content of the aromatic additives for concentrations from 1%.

Vesnin, V. L.; Muradov, V. G.

2011-11-01

86

Determination of polycyclic aromatic hydrocarbons in unfractionated solid solvent-refined coal by matrix isolation fluorescence spectrometry  

SciTech Connect

An untreated solid solvent-refined coal sample yields matrix isolation fluorescence spectra suitable for identification and determination of polycyclic aromatic hydrocarbons. Determination of four polycyclic aromatic hydrocarbons (benzo(a)perylene, benz(a)anthracene and benzo(b)fluorene) in SRC I is reported, as is the determination, by identical spectrometric technique, of the benzo(a)pyrene, content of an NBS shale oil standard reference material.

Perry, M.B.

1983-10-01

87

Phototransformation of polycyclic aromatic hydrocarbons into stable, mutagenic components  

Microsoft Academic Search

This report compares the mutagenicity of photochemical products produced by exposure of the polycyclic aromatic hydrocarbons benzo(a)pyrene and 9,10-dimethylanthracene or the aromatic amines 2-aminofluorene, 2-aminoanthracene and 2-aminonaphthalene to sunlight or to ultraviolet light (UVA). 2-Aminofluorene, giving the most active products, was further investigated with respect to the mechanism of photoactivation and the chemical identity of the photochemical products. Screening of

R. T. Okinaka; J. W. Nickols; T. W. Whaley; G. F. Strniste

1983-01-01

88

Biocatalytic chlorination of aromatic hydrocarbons by chloroperoxidase of Caldariomyces fumago  

Microsoft Academic Search

Chloroperoxidase from Caldariomyces fumago was able to chlorinate 17 of 20 aromatic hydrocarbons assayed in the presence of hydrogen peroxide and chloride ions. Reaction rates varied from 0.6 min?1 for naphthalene to 758 min?1 for 9-methylanthracene. Mono-, di- and tri-chlorinated compounds were obtained from the chloroperoxidase-mediated reaction on aromatic compounds. Dichloroacenaphthene, trichloroacenaphthene, 9,10-dichloroanthracene, chloropyrene, dichloropyrene, dichlorobiphenylene and trichlorobiphenylene were identified

Rafael Vázquez-Duhalt; Marcela Ayala; Facundo J. Márquez-Rocha

2001-01-01

89

Manufacture of aromatic hydrocarbons from coal hydrogenation products  

SciTech Connect

The manufacture of aromatic hydrocarbons from coal distillates was experimentally studied. A flow chart for the production of benzene, ethylbenzene, toluene, and xylenes was designed, which comprised the hydrogen treatment of the total wide-cut (or preliminarily dephenolized) fraction with FBP 425{sup o}C; fractional distillation of the hydrotreated products into IBP-60, 60-180, 180-300, and 300-425{sup o}C fractions; the hydro-cracking of middle fractions for increasing the yield of gasoline fractions whenever necessary; the catalytic reform of the fractions with bp up to 180{sup o}C; and the extraction of aromatic hydrocarbons.

A.S. Maloletnev; M.A. Gyul'malieva [Institute for Fossil Fuels, Moscow (Russian Federation)

2007-08-15

90

Assessment of Aliphatic and Polycyclic Aromatic Hydrocarbons and Trace Elements in Coastal Sediments of the Saronikos Gulf, Greece (Eastern Mediterranean)  

Microsoft Academic Search

Surface sediments from the Saronikos Gulf were analyzed for their aliphatic hydrocarbon (AHC) and polycyclic aromatic hydrocarbon (PAH) content by gas chromatography – mass spectrometry (GC\\/MS). The concentrations of Fe, Cr, As, Sb, Co and Sc were also determined by neutron activation analysis (NAA). The survey was performed at the beginning of the operation of Athens’ sewage primary treatment unit

E. Sklivagou; S. P. Varnavas; I. Hatzianestis; G. Kanias

2008-01-01

91

Polycyclic aromatic hydrocarbon oxidation during prostaglandin biosynthesis  

SciTech Connect

Polycyclic hydrocarbons and other xenobiotics are cooxygenated during the oxidative metabolism of polyunsaturated fatty acids. The products of polycyclic hydrocarbon cooxygenation depend upon the hydrocarbon but they appear to be formed by radical (or electron transfer) mechanisms. The cooxygenations are hydroperoxide-dependent oxidations catalyzed by peroxidases and may be triggered by enzymes which biosynthesize fatty acid hydroperoxides. Prostaglandin endoperoxide synthetase is the principal hydroperoxide-generating system which has been studied to date. The extent to which polyunsaturated fatty acid-dependent cooxygenation operates in vivo is uncertain but preliminary studies suggest it does occur.

Marnett, L.J.

1981-08-10

92

The Concentration of Mild-Extracted Polycyclic Aromatic Hydrocarbons in Sewage Sludges  

Microsoft Academic Search

The present study evaluates the content of the mild-solvent extracted fraction of the polycyclic aromatic hydrocarbons. Ten compounds from the US EPA list (phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chryzene, benzo[b]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene oraz indeno[1,2,3-cd]pyrene) were chosen. The compounds were extracted with n-butanol from 11 sewage sludges that differed both in the total PAH content and in their physicochemical properties. On

Patryk Oleszczuk; Stanis?aw Baran

2004-01-01

93

Experimental and modeling investigation of aromatic and polycyclic aromatic hydrocarbon formation in a premixed ethylene flame  

SciTech Connect

Experimental and detailed chemical kinetic modeling has been performed to investigate aromatic and polyaromatic hydrocarbon formation pathways in a rich, sooting, ethylene-oxygen-argon premixed flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.5 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer (GC/MS) technique. Measurements were made in the flame and post-flame zone for a number of low molecular weight species, aliphatics, aromatics and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-aromatic fused rings. The modeling results show the key reaction sequences leading to aromatic and polycyclic aromatic hydrocarbon growth involve the combination of resonantly stabilized radicals. In particular, propargyl and 1-methylallenyl combination reactions lead to benzene and methyl substituted benzene formation, while polycyclic aromatics are formed from cyclopentadienyl radicals and fused rings that have a shared C{sub 5} side structure. Naphthalene production through the reaction step of cyclopentadienyl self-combination and phenanthrene formation from indenyl and cyclopentadienyl combination were shown to be important in the flame modeling study. The removal of phenyl by O{sub 2} leading to cyclopentadienyl formation is expected to play a pivotal role in the PAH or soot precursor growth process under fuel-rich oxidation conditions.

Castaldi, M.J.; Marinov, N.M.; Melius, C.F. [and others

1996-02-01

94

Contorted polycyclic aromatic hydrocarbons: Synthesis, structure, and function  

Microsoft Academic Search

The following thesis focuses on novel polycyclic aromatic hydrocarbons (PAHs) as materials for electronic applications. Many of the molecules described herein fall under the subheading of contorted PAHs indicating their distortion from the planar structure that is typical of PAHs. Chapter two describes a series of contorted PAHs that were synthesized enroute to a molecular bowl. These molecules represent some

Noah Jonathan Tremblay

2009-01-01

95

MTBE and aromatic hydrocarbons in North Carolina stormwater runoff  

Microsoft Academic Search

A total of 249 stormwater samples were collected from 46 different sampling locations in North Carolina over an approximate 1-year period and analyzed to identify land use types where fuel oxygenates and aromatic hydrocarbons may be present in higher concentrations and at greater frequency. Samples were analyzed by gas chromatography–mass spectrometry in ion selective mode to achieve a quantitation limit

Robert C. Borden; David C. Black; Kathleen V. McBlief

2002-01-01

96

Estimating adsorption of polycyclic aromatic hydrocarbons on soils  

Microsoft Academic Search

This paper presents a synthesis of information available on the adsorption of polycyclic aromatic hydrocarbons (PAH) in water\\/soil systems. Included is an analysis of how limited adsorption data for PAH on soils may be used in conjunction with PAH molecular characteristics to predict adsorption properties for a wide range of PAH and soils. Also presented is an evaluation of procedures

DAVID A. DZOMBAK; RICHARD G. LUTHY

1984-01-01

97

Ozone degradation of polycyclic aromatic hydrocarbons adsorbed on asbestos  

SciTech Connect

The polycyclic aromatic hydrocarbons (PAH) represent a major source of pollution. The adsorption properties of chrysotile give us a good application as an asbestos filter and the regeneration can be made by ozonolysis for a complete destruction to non-toxic compounds. 13 references, 2 figures, 3 tables.

Menard, H.; Lalancette, J.M.; Lefebvre, Y.; Belanger, D.

1986-03-01

98

Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review  

Microsoft Academic Search

PAHs are aromatic hydrocarbons with two or more fused benzene rings with natural as well as anthropogenic sources. They are widely distributed environmental contaminants that have detrimental biological effects, toxicity, mutagenecity and carcinogenicity. Due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity, the PAHs have gathered significant environmental concern. Although PAH may undergo adsorption, volatilization, photolysis, and chemical

A. K. Haritash; C. P. Kaushik

2009-01-01

99

Polycyclic aromatic hydrocarbons in Estonian soil: contamination and profiles  

Microsoft Academic Search

The distribution and accumulation of polycyclic aromatic hydrocarbons (PAH) in soil as well as PAH profiles have been investigated in areas with different anthropogenic pollution such as the city of Tallinn, the towns of Pärnu and Kohtla-Järve and some rural areas. PAH were identified in 147 soil samples (0–10 cm upper layer) collected in September 1996. The typical ? PAH

M Trapido

1999-01-01

100

Woodburning as a source of atmospheric polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Airborne particulate matter containing polycyclic aromatic hydrocarbons derived from burning natural vegetation and paper products in a variety of ways was collected and analyzed by HPLC. Similar profiles of compounds resulted from most of the combustion sources that do not involve fossil fuels and that are likely to contribute to Sydney's atmospheric particulates. In addition, the profiles did not change

Diana J. Freeman; Frank C. R. Cattell

1990-01-01

101

Air sampling and analysis of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) occur in particles or in vapour phase. The size of the particles is affected by the season: in the winter there is a shift from large to small particles. PAHs, which are associated with particulate matter, are usually collected on filters and are then vaporized from the filter, or exist in the vapour phase and are

Kimmo Peltonen; Terhi Kuljukka

1995-01-01

102

Polycyclic Aromatic Hydrocarbon (PAH) Ecotoxicology in Marine Ecosystems  

Microsoft Academic Search

Low levels of oil and hence polycyclic aromatic hydrocarbons (PAHs) are naturally present in the marine environment, although levels have increased significantly following human extraction and use of oil and gas. Other major anthropogenic sources of PAHs include smelters, the use of fossil fuels in general, and various methods of waste disposal, especially incineration. There are two major sources for

Ketil Hylland

2006-01-01

103

Polycyclic aromatic hydrocarbons in air and snow from Fairbanks, Alaska  

Microsoft Academic Search

There has been increasing interest regarding the use of passive air samplers as tools for monitoring organic pollutants in the atmosphere. In this study we report results obtained from passive air samplers that were deployed in both indoor and outdoor environments across the City of Fairbanks, AK, for the polycyclic aromatic hydrocarbons (PAHs) during winter 2009. It is demonstrated that

Todd Gouin; David Wilkinson; Stephen Hummel; Ben Meyer; Andrew Culley

2010-01-01

104

Enhanced Bioremediation of Polycyclic Aromatic Hydrocarbons by Environmentally Friendly Techniques  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are recognized as a worldwide environmental contamination problem because of their intrinsic chemical stability, high resistance to various transformation processes, and toxicity property. Because of the wide distribution of the PAHs in the environment, human exposure to the PAHs is likely to occur from dermal contact, ingestion of particles, inhalation of airborne dust, or bioaccumulation in

Huey-Min Hwang; Xiaoke Hu; Xueheng Zhao

2007-01-01

105

Polycyclic aromatic hydrocarbons in fuel-oil contaminated soils, Antarctica  

Microsoft Academic Search

Where fuel oil spills have occurred on Antarctic soils polycyclic aromatic hydrocarbons (PAH) may accumulate. Surface and subsurface soil samples were collected from fuel spill sites up to 30 years old, and from nearby control sites, and analysed for the 16 PAHs on the USEPA priority pollutants list, as well as for two methyl substituted naphthalenes, 1-methylnaphthalene and 2-methylnaphthalene. PAH

Jackie Aislabie; Megan Balks; Norma Astori; Gavin Stevenson; Robert Symons

1999-01-01

106

Possible Molecular Targets of Halogenated Aromatic Hydrocarbons in Neuronal Cells  

Microsoft Academic Search

Halogenated aromatic hydrocarbon including polychlorinated biphenyls (PCBs) are persistent and bioaccumulative environmental toxicants. Although health effects associated with exposure to these chemicals, including motor dysfunction and impairment in memory and learning, have been identified, their molecular site of action is unknown. Previous study from this laboratory demonstrated that, while ortho PCBs perturbed intracellular signaling mechanisms including Ca2+ homeostasis, receptor-mediated inositol

Jae-Ho Yang; Prasada Rao S. Kodavanti

2001-01-01

107

Polycyclic aromatic hydrocarbons and fatal ischemic heart disease  

Microsoft Academic Search

BACKGROUND: Several toxicologic and epidemiologic studies have produced evidence that occupational exposure to polycyclic aromatic hydrocarbons (PAH) is a risk factor for ischemic heart disease (IHD). However, a clear exposure-response relation has not been demonstrated. METHODS: We studied a relation between exposure to PAH and mortality from IHD (418 cases) in a cohort of 12,367 male asphalt workers from Denmark,

Igor Burstyn; Hans Kromhout; Timo Partanen; Ole Svane; S. Langard; Wolfgang Ahrens; Timo Kauppinen; I. Stucker; Judith Shaham; Dick Heederik; Gilles Ferro; P. Heikkila; Christoffer Johansen; Britt G. Randem; Paolo Boffetta

2005-01-01

108

Polycyclic Aromatic Hydrocarbons in an industrialized urban area  

Microsoft Academic Search

Urbanization, agricultural intensification and industrialization are contributing to erosion, local and diffuse contamination and sealing of soil surfaces, resulting in soil quality degradation. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in urban environments and considered good markers of anthropogenic activities such as traffic, industry, domestic heating and agriculture. Although they are subject to biodegradation and photodegradation, once in the soil, they

A. Cachada; R. Pereira; E. Ferreira da Silva; A. C. Duarte

2009-01-01

109

Occurrence of chlorinated polynuclear aromatic hydrocarbons in tap water  

Microsoft Academic Search

Organic compounds in tap waters were extracted by a modified continuous liquid-liquid extractor and analyzed by computerized gas chromatography\\/mass spectrometry using a fused silica capillary column. The results indicate the presence of monochlorinated derivatives of naphthalene, dibenzofuran, fluorene, fluorenone, phenanthrene, and fluoranthene and dichlorinated derivatives of naphthalene, phenanthrene, and fluoranthene. The parent polynuclear aromatic hydrocarbons (PAHs) and their oxygenated derivatives

Hiroaki Shiraishi; Norman H. Pilkington; Akira Otsuki; Keiichiro Fuwa

1985-01-01

110

Polycyclic aromatic hydrocarbons in olive oils on the Italian market  

Microsoft Academic Search

The six olive oils and seven virgin olive oils which are most consumed in Italy were analysed for 28 polycyclic aromatic hydrocarbons (PAHs). The aim was to evaluate whether a carcinogenic hazard for the general population can derive from the dietary intake of this food, which is consumed particularly highly in the Mediterranean area. The analytical method involved extraction by

Edoardo Menichini; Adriana Bocca; Franco Merli; Daniela Ianni; Fabio Monfredini

1991-01-01

111

Bioavailability of Polycyclic Aromatic Hydrocarbons in Soils and Sediments  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) constitute a group of priority pollutants which are of increasing environmental concern because of their adverse effects on humans, animals, and plants. Soils and sediments generally serve as a sink for PAHs, which leads to the accumulation of PAHs at contaminated sites. In the last decade, bioremediation has been frequently used for the clean-up of such

M. P. Cuypers

2001-01-01

112

Atmospheric polycyclic aromatic hydrocarbons: Source attribution, emission factors and regulation  

Microsoft Academic Search

There is an increasing concern about the occurrence of polycyclic aromatic hydrocarbons (PAHs) in the environment as they are ubiquitous in ambient air and some of them are among the strongest known carcinogens. PAHs and their derivatives are produced by the incomplete combustion of organic material arising, partly, from natural combustion such as forest and volcanic eruption, but with the

Khaiwal Ravindra; Ranjeet Sokhi; René Van Grieken

2008-01-01

113

Structure-biodegradability relationships of polycyclic aromatic hydrocarbons in soil  

Microsoft Academic Search

The potential of some polycyclic aromatic hydrocarbons (PAH) to be metabolized to mutagenic and\\/or carcinogenic compounds (Cerniglia 1984, Gibson & Subramanian 1984) has caused concern for environmental pollution by this class of residues. In industrialized countries, pollution by PAH is primarily associated with the processing, combustion and disposal of fossil fuels (Bartha & Bossert 1984, Hites& LaFlamme 1977), but low

Ingeborg D. Bossert; Richard Bartha

1986-01-01

114

Interactions of polyhalogeneted aromatic hydrocarbons with thyroid hormone metabolism  

Microsoft Academic Search

This thesis deals with the possible interactions of polyhalogenated aromatic hydrocarbons and\\/or their metabolites with thyroid hormone metabolism. This chapter summarizes firstly the effects of thyroid hormone on the induction of biotransformation enzymes by PHAHs. Secondly, the results on the inhibition of thyroid hormone sulfation by hydroxylated metabolites of PHAH are summarized. Some conclusions and remarks on the overall implications

A. G. Schuur

1998-01-01

115

COHERENT ANTI-STOKES RAMAN SPECTROSCOPY OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

Coherent anti-Stokes Raman spectroscopy (CARS) was used to obtain Raman spectra of thirteen polycyclic aromatic hydrocarbons (PAHs) composed of between three and seven fused rings. The compounds were pumped in the resonance and preresonance regions to obtain the sensitivity neces...

116

Dermal Exposure to Polycyclic Aromatic Hydrocarbons among Road Pavers  

Microsoft Academic Search

Objectives: Dermal exposure to polycyclic aromatic hydrocarbons (PAHs) and the role of an industrial by-product, coal fly ash, on workers' PAH exposure were investigated during stone mastic asphalt (SMA) paving and remixing. Methods: PAH exposure was measured at eight sites during the laying of SMA containing coal fly ash or limestone (conventional SMA) as the filler. Six of the surveys

VIRPI VAANANEN; MERVI HAMEILA; PENTTI KALLIOKOSKI; ELINA NYKYRI; PIRJO HEIKKILA

2005-01-01

117

Determination of Heavy Polycyclic Aromatic Hydrocarbons (PAH) in Fishery Products  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) determination in a food matrix is a topic of interest for routine quality control or screening analyses. For currently available methods, sample preparation is laborious and time-consuming.The determination of PAH in fishery products developed in this paper is based on Conte and Moret's method for vegetable oils. Fat is extracted from 2 g of dehydrated sample,

Cristina Sobrado; Ma Corina Quintela; José C. González; Juan M. Vieites

2004-01-01

118

Toxicity of Polycyclic Aromatic Hydrocarbons to the Nematode Caenorhabditis elegans  

Microsoft Academic Search

The presence of polycyclic aromatic hydrocarbons (PAHs) in the environment has attracted much concern owing to their mutagenic and carcinogenic properties. Regulatory authorities have favored the use of biological indicators as an essential means of assessing potential toxicity of environmental pollutants. This study aimed to assess the toxicity of acenaphthene, phenanthrene, anthracene, fluoranthene, pyrene, and benzo[a]pyrene to Caenorhabditis elegans by

Beke T. Sese; Alastair Grant; Brian J. Reid

2009-01-01

119

Sorption characteristics of polycyclic aromatic hydrocarbons in aluminum smelter residues  

Microsoft Academic Search

High temperature carbon oxidation in primary aluminum smelters results in the release of polycyclic aromatic hydrocarbons (PAH) into the environment. The main source of PAH are the anodes, which are composed of petroleum coke (black carbon, BC) and coal tar pitch. To elucidate the dominant carbonaceous phase controlling the environmental fate of PAH in aluminum smelter residues (coke BC and\\/or

Gijs D. Breedveld; Emilien Pelletier; Richard St. Louis; Gerard Cornelissen

2007-01-01

120

CHILDREN'S AGGREGATE EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS (PAHS)  

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) have been frequently detected at children's homes and day care centers and may pose health concerns due to their carcinogenicity. Most PAHs have been persistent indoors and outdoors, therefore, children may be exposed to chronic low level...

121

Aromatic hydrocarbon "humps" in the marine environment: unrecognized toxins?  

PubMed

Gas chromatographic analysis of the hydrocarbons of environmental samples often reveals that unresolved complex mixtures (UCMs) or gas chromatographic "humps" of aliphatic and aromatic hydrocarbons are most abundant--yet little consideration seems to have been given to the possible toxicological impacts of hydrocarbon "humps". Here we show, using a well-accepted bioassay, that monoaromatic components of a UCM of hydrocarbons from a crude oil elicit a sublethal toxic response in a typical marine pollution indicator organism (the mussel, Mytilus edulis). Furthermore, coastal U.K. mussels shown previously to have unexplained impaired health contained high concentrations of UCMs, including monoaromatic UCMs. These findings may have important implications for our understanding of the toxicological sublethal effects of oil residues in the environment. Given the relatively resistant nature of UCM hydrocarbons, the effects of both acute oil spills and more chronic discharges may need further consideration. PMID:11452586

Rowland, S; Donkin, P; Smith, E; Wraige, E

2001-07-01

122

Aromatic and polycyclic aromatic hydrocarbon formation in a laminar premixed n-butane flame  

SciTech Connect

Experimental and detailed chemical kinetic modeling work has been performed to investigate aromatic and polycyclic aromatic hydrocarbon (PAH) formation pathways in a premixed, rich, sooting, n-butane-oxygen-argon burner stabilized flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.6 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer technique. Measurements were made in the main reaction and post-reaction zones for a number of low molecular weight species, aliphatics, aromatics, and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-fused aromatic rings. Reaction flux and sensitivity analysis were used to help identify the important reaction sequences leading to aromatic and PAH growth and destruction in the n-butane flame. Reaction flux analysis showed the propargyl recombination reaction was the dominant pathway to benzene formation. The consumption of propargyl by H atoms was shown to limit propargyl, benzene, and naphthalene formation in flames as exhibited by the large negative sensitivity coefficients. Naphthalene and phenanthrene production was shown to be plausibly formed through reactions involving resonantly stabilized cyclopentadienyl and indenyl radicals. Many of the low molecular weight aliphatics, combustion by-products, aromatics, branched aromatics, and PAHs were fairly well simulated by the model. Additional work is required to understand the formation mechanisms of phenyl acetylene, pyrene, and fluoranthene in the n-butane flame. 73 refs.

Marinov, N.M.; Pitz, W.J.; Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States); Vincitore, A.M.; Castaldi, M.J.; Senkan, S.M. [Univ. of California, Los Angeles, CA (United States); Melius, C.F. [Sandia National Labs., Livermore, CA (United States)

1998-07-01

123

Analogs of solid nanoparticles as precursors of aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Context. Aromatic =CH and C=C vibrational bands have been observed within shocked interstellar regions, indicating the presence of aromatic emission carriers such as PAHs, which may have been created from adjacent molecular cloud material by interaction with a shock front. Aims: We investigate the evolution of the aromatic =CH and C=C vibrational modes at 3.3 and 6.2 ?m wavelength in heated HAC materials, PAHs and mixed PAHs and HACs, respectively, aiming at an explanation of the evolution of carbonaceous dust grains in the shocked regions. Methods: Materials used in these analogs (HAC and PAH materials) were prepared by the laser ablation and the laser pyrolysis methods, respectively. The transmission electron microscopy (TEM) in high-resolution mode was used as an analytical technique to characterize the aromatic layers in HACs. Spectroscopic analysis was prformed in the mid-IR range. Results: A remarkable destruction of aliphatic structures in HACs has been observed with the thermal processing, while aromatic structures become dominating by increasing the diameters of the graphene layers. The aromatic bands at 3.3 and 6.2 ?m, observed in the laboratory spectra of PAHs and of the combination of the PAHs and HAC materials, are also clearly observed in the spectrum of the heated HACs. These bands agree with those of aromatic bands observed in astronomical observations. Conclusions: Aromatization of HACs could be a pre-stage in the decomposition process of hydrocarbons that form PAH-clusters in such hot interstellar medium.

Gadallah, K. A. K.; Mutschke, H.; Jäger, C.

2013-06-01

124

Aromaticity of closed-shell charged polybenzenoid hydrocarbons.  

PubMed

The aromatic stabilization of closed-shell charged polybenzenoid hydrocarbons (PBHs) has been scrutinized by means of energetic and magnetic aromaticity criteria and by direct measures of electron delocalization. Thus, topological resonance energies and their circuit contributions, ring current maps, and multicenter delocalization indices have been calculated for a series of 18 polybenzenoid cations containing from 3 to 10 benzene rings. All calculations indicate that the closed-shell cations have a similar degree of aromaticity compared to that of the corresponding closed-shell neutral PBHs. All cations investigated display a large degree of electronic delocalization in the ring, accompanied by significant aromatic stabilization and a strong diatropic peripheral electron current. Graph theoretical models describe perfectly the aromatic features of these hydrocarbon fragments, showing how they can be understood as a superposition of specific neutral PBHs. The large aromatic character of these systems suggests they may be relatively stable upon formation at combustion conditions, like those given in the interstellar medium. It has been postulated that closed-shell fragments of PBHs may play an important role in the photoluminescent phenomenon known as extended red emission. PMID:23675945

Ramos-Berdullas, Nicolás; Radenkovi?, Slavko; Bultinck, Patrick; Mandado, Marcos

2013-05-28

125

Flotation activity and thermodynamic adsorption functions of aromatic hydrocarbons  

SciTech Connect

Apolar reagents, used for the flotation of various minerals, contain a significant amount of aromatic hydrocarbons. In this paper, the authors study the flotation activity and thermodynamic adsorption functions of alkylated and polymethylated benzenes with mono- and diisomeric substituents containing various functional groups in the benzene ring. Aromatic hydrocarbons are used widely for the commercial flotation of graphite. The change in free energy and entropy for the adsorption of hydrocarbons with small surface packing at 363/sup 0/K were calculated from the chromatographic data. Benzene is shown to be a poor reagent for the flotation of graphite. Among other conclusions drawn, alkylation, polymethylation and halogenation of benzene increases the thermo-dynamic adsorption functions and flotation activity.

Chizhevskii, V.B.

1988-03-01

126

PPP Hamiltonian for polar polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Total energies of charged states and configurations of different spin multiplicity of two polar non-alternant polycyclic aromatic\\u000a hdrocarbons (PAH), namely, pentaheptafulvalene and azulene, calculated by means of a Multi-Configurational (MCSCF) method\\u000a which includes correlation only amongst ? orbitals, have been fitted by exact solutions of the Pariser-Parr-Pople (PPP) and the Hubbard Hamiltonians for ? electrons. As both molecules are planar,

E. San-Fabián; A. Guijarro; J. A. Vergés; G. Chiappe; E. Louis

2011-01-01

127

SOLUBILITY BEHAVIOR OF THREE AROMATIC HYDROCARBONS IN DISTILLED WATER AND NATURAL SEAWATER  

EPA Science Inventory

The solubilities of three aromatic hydrocarbons were determined at 25 C. in natural seawater and distilled water. Saturation was achieved by equilibration of water and an excess of hydrocarbon by mechanical agitation. All three hydrocarbons, toluene, acenaphthene, and pyrene, wer...

128

Exciton properties of selected aromatic hydrocarbon systems  

NASA Astrophysics Data System (ADS)

We have examined the singlet excitons in two representatives of acene-type (tetracene and pentacene) and phenacene-type (chrysene and picene) molecular crystals, respectively, using electron energy-loss spectroscopy at low temperatures. We show that the excitation spectra of the two hydrocarbon families significantly differ. Moreover, close inspection of the data indicates that there is an increasing importance of charge-transfer excitons at lowest excitation energy with increasing length of the molecules.

Roth, Friedrich; Mahns, Benjamin; Hampel, Silke; Nohr, Markus; Berger, Helmuth; Büchner, Bernd; Knupfer, Martin

2013-02-01

129

Biodegradation of aromatic hydrocarbons in an extremely acidic environment  

PubMed

The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve 14CO2 from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values. PMID:9797263

Stapleton; Savage; Sayler; Stacey

1998-11-01

130

Biodegradation of Aromatic Hydrocarbons in an Extremely Acidic Environment  

PubMed Central

The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve 14CO2 from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values.

Stapleton, Raymond D.; Savage, Dwayne C.; Sayler, Gary S.; Stacey, Gary

1998-01-01

131

Occupational exposure to Polycyclic Aromatic Hydrocarbons in wood dust  

NASA Astrophysics Data System (ADS)

Sino-nasal cancer (SNC) represents approximately 3% of Oto-Rhino-Laryngology (ORL) cancers. Adenocarcinoma SNC is an acknowledged occupational disease affecting certain specialized workers such as joiners and cabinetmakers. The high proportion of woodworkers contracting a SNC, subjected to an estimated risk 50 to 100 times higher than that affecting the general population, has suggested various study paths to possible causes such as tannin in hardwood, formaldehyde in plywood and benzo(a)pyrene produced by wood when overheated by cutting tools. It is acknowledged that tannin does not cause cancer to workers exposed to tea dust. Apart from being an irritant, formaldehyde is also classified as carcinogenic. The path involving carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) emitted by overheated wood is attractive. In this study, we measured the particle size and PAHs content in dust emitted by the processing of wood in an experimental chamber, and in field situation. Quantification of 16 PAHs is carried out by capillary GC-ion trap Mass Spectrometric analysis (GC-MS). The materials tested are rough fir tree, oak, impregnated polyurethane (PU) oak. The wood dust contains carcinogenic PAHs at the level of ?g.g-1 or ppm. During sanding operations, the PU varnish-impregnated wood produces 100 times more PAHs in dust than the unfinished wood.

Huynh, C. K.; Schüpfer, P.; Boiteux, P.

2009-02-01

132

Polycyclic aromatic hydrocarbons and esophageal squamous cell carcinoma.  

PubMed

Esophageal cancer (EC) is the 8th most common cancer and the 6th most frequent cause of cancer mortality worldwide. Esophageal squamous cell carcinoma (ESCC) is the most common type of EC. Exposure to polycyclic aromatic hydrocarbons (PAHs) has been suggested as a risk factor for developing ESCC. In this paper we will review different aspects of the relationship between PAH exposure and ESCC. PAHs are a group of compounds that are formed by incomplete combustion of organic matter. Studies in humans have shown an association between PAH exposure and development of ESCC in many populations. The results of a recent case-control study in a high risk population in northeastern Iran showed a dramatic dose-response relationship between PAH content in non-tumor esophageal tissue (the target tissue for esophageal carcinogenesis) and ESCC case status, consistent with a causal role for PAH exposure in the pathogenesis of ESCC.  Identifying the main sources of exposure to PAHs may be the first and most important step in designing appropriate PAH-reduction interventions for controlling ESCC, especially in high risk areas. Coal smoke and drinking mate have been suggested as important modifiable sources of PAH exposure in China and Brazil, respectively. But the primary source of exposure to PAHs in other high risk areas for ESCC, such as northeastern Iran, has not yet been identified. Thus, environmental studies to determining important sources of PAH exposure should be considered as a high priority in future research projects in these areas. PMID:23102250

Roshandel, Gholamreza; Semnani, Shahryar; Malekzadeh, Reza; Dawsey, Sanford M

2012-11-01

133

Polycyclic aromatic hydrocarbon contamination in the Italian diet.  

PubMed

The content of total and carcinogenic polycyclic aromatic hydrocarbons (PAHs) in Italian foods was measured. The highest levels of PAHs were found in pizza baked in wood-burning ovens and barbecued beef and pork. Relatively high levels were also found in beet greens and squash, apples and bread, fried beef, pork and rabbit, cured meats and chocolate. Conversely low levels were detected in potatoes and cooked fish, beverages and eggs. The daily intake of total and carcinogenic PAHs also was calculated by multiplying the average consumption of each food by its mean concentration of PAHs. Cereal and milk products, meat, vegetables and fruits were the highest contributors to total PAH intake, since these products are the most important dietary components in Italy. The calculated total dietary PAH intake was 3 micrograms/day per person. The calculated intake of carcinogenic PAHs was 1.4 microgram/day per person. The dietary intake of PAHs was high compared with the calculated respiratory intake (370 ng/day) owing to polluted city air in Italy. These results confirm that food is the major source of human exposure to PAHs, due in particular to the high consumption of contaminated cereal products. PMID:8522036

Lodovici, M; Dolara, P; Casalini, C; Ciappellano, S; Testolin, G

134

Exposure to polycyclic aromatic hydrocarbons among Dutch children  

SciTech Connect

We determined the urinary 1-hydroxypyrene (1-HP) concentration and the creatinine-adjusted 1-HP concentration in 644 randomly selected Dutch children, aged 1-6 years and living in five areas with roughly different levels of polycyclic aromatic hydrocarbons (PAHs) in soil and ambient air. The presence of other factors that might influence the exposure to PAHs was studied using a questionnaire. To evaluate the reliability of a single urinary 1-HP determination, measurements were repeated after 3 weeks for approximately 200 children. The mean urinary 1-HP content of the total study population was 2.06 nmol/1. This varied from 1.58 nmol/l in the reference area (Flevoland) to 2.71 nmol/l in the valley of the Geul. Only indoor sources of PAHs showed a small, positive association with urinary 1-HP. The urinary 1-HP concentrations of children from the valley of the Geul were higher (p<0.01) and those of children from a suburb of Amsterdam were lower (p<0.01) than those of children from the reference area. The possible ambient environment-related differences were probably too small to be detected in the variations of the intake of PAHs from the daily diet. The reliability of a single 1-HP measurement was low. Similar results were obtained with the creatinine-adjusted data. In one neighborhood built on coal-mine tailings, the urinary 1-HP content in children was weakly but positively associated with the PAH content in the upper soil layer of the garden of their homes. However, this association was not found for the children from the other neighborhood built on coal-mine tailings and with similar PAH levels in soil. 25 refs., 4 tabs.

Wijnen, J.H. van; Slob, R. [Municipal Health Service, Amsterdam (Netherlands); Jongmans-Liedekerken, G. [Health Service East-South Limburg, Heerlen (Netherlands)] [and others

1996-05-01

135

Hydrogenation of aromatic hydrocarbons on nickel catalysts modified with heteropolycompounds  

SciTech Connect

Nickel-containing catalysts on various carriers are being extensively studied and used in industry in numerous processes of hydrogenation of hydrocarbons, including hydrogenation of benzene to cyclohexane in the production of nylon. Present-day nickel catalysts for hydrogenation of benzene to cyclohexane have a number of shortcomings: high metal content in active catalysts (20-50 wt.%); low heat stability; easily poisoned by S- and N-containing compounds (acceptable concentration in the raw material 10/sup -4/-10/sup -2/ wt.%); isomerization action of carriers (methylcyclopentane content in the product should not exceed 2 x 10/sup -2/ wt.%) etc. Catalyst properties may be improved and nickel concentration reduced using special carriers, e.g. ..gamma..-Al/sub 2/O/sub 3/ modified with WO/sub 3/, La/sub 2/O/sub 3/, ZrO/sub 2/ etc. type metal oxides. The need for developing and using special carriers instead of pure ..gamma..-Al/sub 2/O/sub 3/ is a consequence of nickel in concentrations lower than 5 wt.%, forming a low-activity, poorly recoverable spinel, NiAl/sub 2/O/sub 4/ on the surface of ..gamma..-Al/sub 2/O/sub 3/. This study is aimed at preparing and investigating nickel catalysts of hydrogenation of aromatic compounds with a low metal content (1-4 wt.%) on ..gamma..-Al/sub 2/O/sub 3/ with a new type of modifier. 12-th series mixed heteropolytungstates (HPT) with Keggin structure were used as modifiers.

Minachev, Kh.M.; Garanin, V.I.; Navalikhina, M.D.; Mironova, I.L.; Golovina, G.S.

1985-01-01

136

Spectrally Dominant Aromatic Hydrocarbon Compounds on Titan (Invited)  

NASA Astrophysics Data System (ADS)

The surface composition of Titan is still shrouded in mystery. While some compounds have been identified and mapped on Titan's surface, like liquid ethane + methane lakes, and benzene, the compounds responsible for the main spectral properties have remained elusive (Clark et al, 2010, JGR in press). Titan's surface is seen in the near infrared in only a few spectral windows, near 0.94, 1.1, 1.3, 1.6, 2.0, 2.68-2.78, and 4.9-5.1 microns in the Cassini Visual and Infrared Mapping Spectrometer (VIMS) spectral range. The apparent reflectance in these windows generally decreases with increasing wavelength except the 2.7 and 5-micron windows which are similar in level. The decrease has led researchers to infer a number of compounds, responsible for the observed decreasing spectral shape; the most common being water ice. But ice is incompatible with the 2.78/2.68 micron I/F ratio. Many organic compounds have absorptions not seen on Titan, eliminating them as possible major components at the surface. In a broad survey of the reflectance properties of organic compounds we have found that the closest spectral matches to the Titan spectrum is best explained by abundant aromatic hydrocarbons Aromatic hydrocarbons are compatible with all the ratios of reflectances observed through the atmospheric windows, including the 2.68 and 2.78 micron windows. Clark et al. (2010) found a 5.01-micron absorption in some Titan spectra but could not identify a compound. We find that the polycyclic aromatic hydrocarbon (PAH) coronene, consisting of 6 benzene rings matches that feature. Coronene is also a naturally occurring mineral on Earth, known as karpatite. Combinations of PAHs such as coronene, phenanthene (C14H12), pentacene (C22H14) and other aromatic hydrocarbons like indole (C8H7N) match the overall spectral structure of Titan spectra, Further, subtle changes in spectral diversity shown by Clark et al. in the 5-micron window can be explained by variations in the relative abundances of the aromatic hydrocarbons. Indole has a 1.5 micron band that can explain the feature observed in DISR spectra of Titan's surface. Titan's surface seems dominated by aromatic hydrocarbon.

Clark, R. N.; Pearson, N.; Brown, R. H.; Cruikshank, D. P.; Barnes, J. W.; Jaumann, R.; Soderblom, L. A.; Rodriguez, S.; Le Mouélic, S.; Lunine, J. I.; Sotin, C.; Baines, K. H.; Buratti, B. J.; Nicholson, P. D.; Nelson, R.; Stephan, K.

2010-12-01

137

Phototransformation of polycyclic aromatic hydrocarbons into stable, mutagenic components  

SciTech Connect

This report compares the mutagenicity of photochemical products produced by exposure of the polycyclic aromatic hydrocarbons benzo(a)pyrene and 9,10-dimethylanthracene or the aromatic amines 2-aminofluorene, 2-aminoanthracene and 2-aminonaphthalene to sunlight or to ultraviolet light (UVA). 2-Aminofluorene, giving the most active products, was further investigated with respect to the mechanism of photoactivation and the chemical identity of the photochemical products. Screening of HPLC resolved photochemical products demonstrated that the majority of the mutagenicity was localized to one peak - which co-chromatographed with 2-nitrofluorene.

Okinaka, R.T.; Nickols, J.W.; Whaley, T.W.; Strniste, G.F.

1983-01-01

138

Polycyclic aromatic hydrocarbons physically intercalate into duplex regions of denatured DNA  

SciTech Connect

The authors have investigated the physical binding of pyrene and benzo(a)pyrene derivatives to denatured DNA. These compounds exhibit a red shift in their absorbance spectra of 9 nm when bound to denatured calf thymus DNA, compared to a shift of 10 nm when binding occurs to native DNA. Fluorescence from the hydrocarbons is severely quenched when bound to both native and denatured DNA. Increasing sodium ion concentration decreases binding of neutral polycyclic aromatic hydrocarbons to native DNA and increases binding to denatured DNA. The direct relationship between binding to denatured DNA and salt concentration appears to be a general property of neutral polycyclic aromatic hydrocarbons. Absorption measurements at 260 nm were used to determine the duplex content of denatured DNA. When calculated on the basis of duplex binding sites, equilibrium constants for binding of 7,8,9,10-tetrahydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene to denatured DNA are an order of magnitude larger than for binding to native DNA. The effect of salt on the binding constant was used to calculate the sodium ion release per bound ligand, which was 0.36 for both native and denatured DNA. Increasing salt concentration increases the duplex content of denatured DNA, and it appears that physical binding of polycyclic aromatic hydrocarbons consists of intercalation into these sites.

Wolfe, A.; Shimer, G.H. Jr.; Meehan, T.

1987-10-06

139

Effect of condensed organic matter on solvent extraction and aqueous leaching of polycyclic aromatic hydrocarbons in soils and sediments  

Microsoft Academic Search

The contents of nonhydrolyzable organic matter (NHC) and black carbon (BC) were measured in soils and sediments from the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons (PAHs) were extracted respectively by Soxhlet and an accelerated solvent extraction device (ASE) using different solvents. In addition, sequential aqueous leaching at different temperatures was carried out. The PAH content extracted with the

Yong Ran; Ke Sun; Xiaoxuan Ma; Guohui Wang; Peter Grathwohl; Eddy Y. Zeng

2007-01-01

140

Polycyclic aromatic hydrocarbons in agricultural soils in Poland: preliminary proposals for criteria to evaluate the level of soil contamination  

Microsoft Academic Search

The contamination of agricultural soils in the Upper Silesia region of Poland with polycyclic aromatic hydrocarbons (PAH) was evaluated on the basis of three criteria: the sum of PAH content; the number of exceeded reference values for individual PAH (according Dutch regulations); the author's preliminary proposals for agricultural lands in Poland (the sum of PAH content normalized to “average soil”

Barbara Maliszewska-Kordybach

1996-01-01

141

Evaluation of atmospheric transport as a nonpoint source of polycyclic aromatic hydrocarbons in marine sediments of the Eastern Mediterranean  

Microsoft Academic Search

Coastal marine sediment, air and seawater samples were collected at six sampling stations in the Eastern Mediterranean Sea distant from pollutant point sources. All sediment samples were analyzed to determine polycyclic aromatic hydrocarbon (PAH), black carbon (BC) and organic carbon (OC) contents. The PAH contents of gaseous and seawater samples of the study were determined in order to evaluate the

Manolis Tsapakis; Euripides G. Stephanou; Ioannis Karakassis

2003-01-01

142

Polycyclic aromatic hydrocarbons in Saccoglossus kowalewskyi (Agassiz)  

NASA Astrophysics Data System (ADS)

Hydrocarbon extracts were analyzed from Saccoglossus kowalewskyi, a deposit-feeding enteropneust worm, and from surface sediments from Cape Cod, MA. Worms were held in experimental aquaria in sieved sediments and flowing seawater for four months and then fed sediments mixed with creosote, lampblack or clean sediment for two weeks as analogues of sediments containing degraded oil and pyrogenic compounds. Worms from all treatments contained polyaromatic hydrocarbons (PAHs) in amounts and composition that indicate that the worms were contaminated with weathered No. 2 fuel oil before our experimental treatment and that the contamination persisted for four months in clean conditions. The contamination was not detected in the clean sediments used in the experiment. The worms accumulated steroid transformation products in greater abundance than the odd chain n-alkanes that dominated the sediment extractions. This may indicate selective assimilation of algal detritus and microbial products over salt marsh detritus. Worms, actively feeding during the experiment, contained 1-3 × 10 -6 g g -1 dry weight of unknown brominated compounds which were not detected in the sediments. These compounds are similar to bromopyrroles found elsewhere in enteropneusts, polychaetes and bacteria and may cause substantial interference in analyses for some industrial pollutants.

Carey, D. A.; Farrington, J. W.

1989-08-01

143

Polycyclic aromatic hydrocarbons: Primitive pigment systems in the prebiotic environment  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAH) in the form of polymerized derivatives represent over 90% of the organic material of carbonaceous chondrites. It now appears likely that there was substantial survival of the organic content of meteoritic and cometary infall during late accretion, so that PAH would presumably be major components of the organic inventory present on the prebiotic Earth. An important question relative to chemical evolution and energy transduction is the nature of pigments which could be available to make light energy available to the earliest cellular forms of life. PAH and their derivatives all absorb light in the near UV and blue wavelengths, and are candidates for primitive pigments. We have explored this possibility in a model system consisting of mixtures of pyrene, fluoranthene and pyrene derivatives with hexadecane, dispersed in dilute salt solutions. Upon illumination, photochemical oxidation of the hexadecane occurs, with long-chain amphiphiles such as 2-hexadecanone and 2-hexadecanol as products. Because the reaction proceeds under strictly anaerobic conditions, the source of oxygen is apparently water. We also observed acid pH shifts during illumination. Photochemical production of hydrogen ion is significant, in that chemiosmotic proton gradients across membranes are used by all contemporary cells as a source of energy for ATP synthesis and nutrient transport. To test whether the protons could be used to transduce light energy into a useful form, PAH derivatives were included in lipid bilayer membranes (liposomes). Upon illumination, protons (or acidic products) were produced and accumulated inside the vesicles, so that substantial pH gradients were established across the membranes, acid inside. We conclude that PAH dissolved in aliphatic hydrocarbons absorb light energy and use it to oxidize the hydrocarbon to long-chain amphiphilic molecules. The oxidation is accompanied by release of protons. If PAH derivatives are included in the bilayer membrane of lipid vesicles, protons accumulate within the membrane-bounded volumes to form proton gradients. This system provides a useful model of a primitive photochemical reaction in which light energy is transduced into potentially useable forms.

Deamer, D. W.

144

DETERMINATION OF AMINO DERIVATIVES OF POLYCYCLIC AROMATIC HYDROCARBONS USING CAPILLARY ELECTROPHORESIS  

Microsoft Academic Search

A simple and sensitive capillary electrophoretic method was developed for the separation and determination of selected carcinogenic amino derivatives of polycyclic aromatic hydrocarbons. The influence of pH and content of methanol in the background electrolyte on electrophoretic mobilities of 2-aminofluorene, 2,7-diaminofluorene, 1-aminonaphthalene, 1-aminopyrene and 6-aminochrysene was studied. The detection limits were estimated to be 2.5 × 10 mol.l for 2-aminofluorene,

Martin Pumera; Jan Muziká?; Ji?í Barek; Ivan Jelínek

2001-01-01

145

Polycyclic Aromatic Hydrocarbons in Superficial Sediments from Ghar El Melh Lagoon, Tunisia  

Microsoft Academic Search

The concentrations of 17 polycyclic aromatic hydrocarbons (PAHs) were determined in 12 superficial sediments collected from\\u000a the Ghar El Melh lagoon. Sediment samples were extracted by Soxhlet, and analyzed by Gas chromatography with flame ionisation\\u000a detector (FID). PAH concentrations, ranged from 39.59 to 655.28 ng\\/g on a dry weight. Total PAH concentrations were not correlated\\u000a with organic carbon (OC) content or

W. Ben Ameur; S. Trabelsi; M. R. Driss

2010-01-01

146

The Distribution and Sources of Polycyclic Aromatic Hydrocarbons in Surface Sediments Along the Egyptian Mediterranean Coast  

Microsoft Academic Search

Coastal marine sediment samples were collected from 31 sampling stations along the Egyptian Mediterranean Sea coast. All sediment\\u000a samples were analyzed to determine aliphatic and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC)\\u000a contents and grain size analysis. Total concentrations of 16 EPA-PAHs in the sediments were varied from 88 to 6338 ng g?1 with an average

Ahmed El Nemr; Tarek O. Said; Azza Khaled; Amany El-Sikaily; Aly M. A. Abd-Allah

2007-01-01

147

Determination of Polycyclic Aromatic Hydrocarbons and Trace Metals in New Orleans Soils and Sediments  

Microsoft Academic Search

Soil and sediment samples from New Orleans have been collected and analyzed for contamination by 16 polycyclic aromatic hydrocarbons (PAHs) and 8 trace metals. Total PAH contents were found to vary from 40 ? g\\/kg to 40,000 ? g\\/kg, and concentrations of total metals varied in the range of 80 mg\\/kg and 7600 mg\\/kg. Source analysis of PAHs using diagnostic

GUANGDI WANG; HOWARD W. MIELKE; VAN QUACH; CHRIS GONZALES; QIANG ZHANG

2004-01-01

148

Influence of humic substances on the formation of chlorinated polycyclic aromatic hydrocarbons during chlorination of polycyclic aromatic hydrocarbon polluted water  

SciTech Connect

Chlorinated polycyclic aromatic hydrocarbons (PAH) are present at nanogram per liter levels in lake water. Some of these compounds are known to be mutagenic in the Ames Salmonella test. The PAH compounds fluorene, anthracene, fluoranthene, and benzo(a)pyrene were dissolved in lake water with low humus content and in humus water with 9.17 mg of total organic carbon/L, followed by sodium hypochlorite chlorination at different concentrations. Reaction of PAH and formation of chlorinated PAH were measured by cyclohexane extraction of the samples 3 days after chlorination and gas chromatography/mass spectrometry analyses of the extracts. The PAH-chlorine reaction was found to be dependent upon the concentration of free active chlorine in the water, and the presence of humic substances was found to affect the formation of chlorinated PAH. Chlorinated PAH were formed in the lake water samples of fluoranthene and benzo(a)pyrene, but no chlorinated PAH were detected in the presence of humic substances.

Johnsen, S.; Gribbestad, I.S.

1988-08-01

149

Biogenic Contributions to Aromatic Hydrocarbon Production over Continental North America  

NASA Astrophysics Data System (ADS)

A comprehensive suite of temporally and vertically resolved volatile organic compound (VOC) measurements were conducted at the Boulder Atmospheric Observatory (BAO) in Erie, Colorado from 18 February to 13 March 2011 as part of the Nitrogen, Aerosol Composition, and Halogens on a Tall Tower (NACHTT) campaign. Specifically, this work investigates and quantifies the contribution of monoterpene oxidation to the secondary production of aromatic hydrocarbons and secondary organic aerosol (SOA) precursor gases. To date, this area of research has been largely unexplored; however, recent results from laboratory experiments have suggested that biogenic VOC (BVOC) oxidation should be considered as an important source of aromatic hydrocarbons, especially in rural and remote environments. The VOC measurements conducted during the NACHTT campaign provide diurnally and vertically resolved speciated monoterpene data over mid-latitude North America. New insight on biogenic emissions, their subsequent chemical transformations and influences on oxidant cycling will be explored.

Sive, B. C.; Russo, R.; Zhou, Y.; Swarthout, R.; Hart, A.

2011-12-01

150

Dermal exposure to polycyclic aromatic hydrocarbons in asphalt workers  

Microsoft Academic Search

ObjectivesTo assess dermal exposure to 16 polycyclic aromatic hydrocarbons (PAHs) in asphalt workers by applying polypropylene pads to six body sites (neck, shoulder, upper arm, wrist, groin, ankle), to identify the compounds and exposure sites most representative, and to integrate dermal exposure results with environmental and biological data.MethodsTwenty-four asphalt workers were recruited. Dermal exposure was assessed during a single work

Silvia Fustinoni; Laura Campo; Piero E Cirla; Irene Martinotti; Marina Buratti; Omar Longhi; Vito Foà; PierAlberto Bertazzi

2009-01-01

151

Heterogeneous ozonation kinetics of polycyclic aromatic hydrocarbons on organic films  

Microsoft Academic Search

The room temperature heterogeneous reaction rates of gas-phase ozone with naphthalene, anthracene, fluoranthene, phenanthrene, pyrene, and benzo[a]pyrene were measured over a range of ozone concentrations from 3.5×1014 to 2.3×1016molec.cm?3. The polycyclic aromatic hydrocarbons (PAHs) were dissolved in organic mixtures composed of octanol or decanol along with proxies for compounds known to be present in “urban grime” films. In all cases,

T. F. Kahan; N.-O. A. Kwamena; D. J. Donaldson

2006-01-01

152

Impacts of charcoal characteristics on sorption of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Sorption of three polycyclic aromatic hydrocarbons (PAHs, phenanthrene, anthracene and pyrene) on three charcoals and their precursor substance (sawdust) was studied. The charcoals obtained by heating at 400°C for different periods were different in chemical composition and structure. Sorption characteristics were described by a Polanyi–Dubinin–Manes model combined with poly-parameter linear free energy relationships. The results revealed that though partition could

Hongwen Sun; Zunlong Zhou

2008-01-01

153

Nanocrystalline Ceria Catalysts for the Abatement of Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Nano-crystalline cerium oxide catalysts have been prepared by precipitation and evaluated for the total catalytic oxidation\\u000a of naphthalene, which is a polycyclic aromatic hydrocarbon (PAH). Ceria synthesised by precipitation with urea was the most\\u000a active catalyst for oxidation of naphthalene to carbon dioxide. The urea precipitated CeO2 demonstrated over 90% naphthalene conversion to carbon dioxide at 175°C (100 ppm naphthalene, GHSV=25,000 h?1),

Tomas Garcia; Benjamin Solsona; Stuart H. Taylor

2005-01-01

154

REMOVING POLYCYCLIC AROMATIC HYDROCARBONS FROM WATER BY ADSORPTION ON SILICAGEL  

Microsoft Academic Search

This study investigates a specific topic of water purification by the adsorption onto silicagel of polycyclic aromatic hydrocarbons (PAHs), which are carcinogenic, toxic and persistent in the environment. Acenaphthene, a representative low molecular PAH with moderate solubility in water, is selected as target compound. Batch kinetic experimental studies were undertaken. Kinetic results were modelled using pseudo-first and pseudo-second-order equations, and

Steven Hall; Raymond Tang; Jan Baeyens; Raf Dewil

2009-01-01

155

Supercritical extraction of polynuclear aromatic hydrocarbons from soil  

SciTech Connect

Adsorption and desorption of polynuclear aromatic hydrocarbons from soil in the presence of supercritical CO[sub 2] is studied. The soil adsorption isotherms are described by the Freundlich and BET models. Polar modifiers like methanol and water are found to exhibit a strong desorptive influence. A simple, single-parameter model using linear desorption kinetics is used to fit the desorption data. 5 refs., 4 figs.

Kothandaraman, S.; Ahlert, R.C.; Venkataramani, E.S.; Andrews, A.T. (Rutgers Univ., Piscataway, NJ (United States))

1992-08-01

156

Photochemical Transformation of Polycyclic Aromatic Hydrocarbons on Solid Particles  

Microsoft Academic Search

Photochemical transformation and adsorption of some polycyclic aromatic hydrocarbons, PAH, e.g., phenanthrene, anthracene and pyrene, on the different particulate matter: alumina, silica and oil-shale fly ash were investigated. Fly ash from oil-shale thermal power plants is characterised by a small specific surface area and a low adsorption capacity in comparison to commercial adsorbents. The surface on which PAH were adsorbed

Erik Teinemaa; Uuve Kirso

1999-01-01

157

Polarographic and voltammetric determination of selected nitrated polycyclic aromatic hydrocarbons  

Microsoft Academic Search

The use of differential pulse polarography, differential pulse voltammetry and adsorptive stripping voltammetry for the determination of trace amounts of selected nitrated polycyclic aromatic hydrocarbons (1-nitropyrene, 9-nitroanthracene, 2-nitrofluorene and 2,7-dinitrofluorene were chosen as model substances) were studied. The influence of pH and the composition of the base electrolyte on the polarographic and voltammetric behaviour of these substances was investigated and

Ji??? Barek; Martin Pumera; Alexandr Muck; Milena Kade?ábková; Ji??? Zima

1999-01-01

158

NMR shifts for polycyclic aromatic hydrocarbons from first-principles  

Microsoft Academic Search

We present first-principles, density-functional theory calculations of the NMR chemical shifts for polycyclic aromatic hydrocarbons, starting with benzene and increasing sizes up to the one- and two-dimensional infinite limits of graphene ribbons and sheets. Our calculations are performed using a combination of the recently developed theory of orbital magnetization in solids, and a novel approach to NMR calculations where chemical

Timo Thonhauser; Davide Ceresoli; Nicola N. Marzari

2009-01-01

159

Chromatographic methods for carcinogenic/mutagenic nitropolycyclic aromatic hydrocarbons.  

PubMed

Nitropolycyclic aromatic hydrocarbons (NPAHs), which are known to be carcinogenic and/or mutagenic, are considered to be one of the air pollutants that cause lung cancer. In the last two decades, a number of sensitive and selective methods have been developed for the determination of NPAHs and related compounds in environmental and biological samples. This paper describes the state of the art of the methods and applications. PMID:11002277

Hayakawa, K

2000-10-01

160

Quantification of nitrated polynuclear aromatic hydrocarbons in atmospheric particulate matter  

Microsoft Academic Search

A derivatization-GC\\/ECD analytical method has been developed. This method involves first the reduction of nitrated polynuclear aromatic hydrocarbons (NPAHs) to their corresponding amino-PAHs by NaBH4. This is followed by derivatization of the amino-PAHs with heptafluorobutyric anhydride (HFBA). Such derivatization provides a polyfluorinated tag to the NPAHs, which can then be detected and quantified at pg levels by GC\\/ECD. Using this

Xu Jinhui; Frank S. C Lee

2000-01-01

161

Biodegradation of aromatic hydrocarbons in an extremely acidic environment  

Microsoft Academic Search

The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the

RAYMOND D. STAPLETON; DWAYNE C. SAVAGE; GARY S. SAYLER; GARY STACEY

1998-01-01

162

Present situation in the identification of polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Recently, the interpretation given to the so-called 'unidentified' infrared emission bands has drastically improved. These bands are attributed to the fundamental vibrations of large molecules known in organic chemistry as Polycyclic Aromatic Hydrocarbons (PAH's). In this paper, we review the main arguments which led to this conclusion and focus our attention to some recent IR and UV spectroscopic studies which allow us to interpret further the main characteristics of astronomical spectra.

Leger, A.; D'Hendecourt, L.; Joblin, C.

1993-12-01

163

Availability of polycyclic aromatic hydrocarbons in aging soils  

Microsoft Academic Search

Purpose  The soil contamination by hydrophobic organic contaminants (HOCs), such as polycyclic aromatic hydrocarbons (PAHs), poses\\u000a great threats to human health and ecological security and attracts worldwide concerns. The total HOC concentrations overestimate\\u000a its available fraction to the soil biota. Increased understanding of the availabilities of PAHs in soil environment will have\\u000a considerable benefits for their risk assessment and be very

Wanting Ling; Yuechun Zeng; Yanzheng Gao; Hongjiao Dang; Xuezhu Zhu

2010-01-01

164

Polycyclic Aromatic Hydrocarbons as Star Formation Rate Indicators  

Microsoft Academic Search

As images and spectra from ISO and Spitzer have provided increasingly\\u000ahigher-fidelity representations of the mid-infrared (MIR) and Polycyclic\\u000aAromatic Hydrocarbon (PAH) emission from galaxies and galactic and\\u000aextra-galactic regions, more systematic efforts have been devoted to\\u000aestablishing whether the emission in this wavelength region can be used as a\\u000areliable star formation rate indicator. This has also been in

Daniela Calzetti

2010-01-01

165

Polycyclic Aromatic Hydrocarbons as Star Formation Rate Indicators  

Microsoft Academic Search

As images and spectra from ISO and Spitzer have provided increasingly higher-fidelity representations of the mid-infrared (MIR) and Polycyclic Aromatic Hydrocarbon (PAH) emission from galaxies and galactic and extra-galactic regions, more systematic efforts have been devoted to establishing whether the emission in this wavelength region can be used as a reliable star formation rate indicator. This has also been in

D. Calzetti

2011-01-01

166

Direct photolysis of polycyclic aromatic hydrocarbons in drinking water sources  

Microsoft Academic Search

The widely used low pressure lamps were tested in terms of their efficiency to degrade polycyclic aromatic hydrocarbons listed as priority pollutants by the European Water Framework Directive and the U.S. Environmental Protection Agency, in water matrices with very different compositions (laboratory grade water, groundwater, and surface water). Using a UV fluence of 1500mJ\\/cm2, anthracene and benzo(a)pyrene were efficiently degraded,

S. Sanches; C. Leitão; A. Penetra; V. V. Cardoso; M. J. Benoliel; M. T. Barreto Crespo; V. J. Pereira

2011-01-01

167

Polycyclic aromatic hydrocarbons in selected foods; analysis and occurrence  

Microsoft Academic Search

Some methodological aspects of the determination of polycyclic aromatic hydrocarbons (PAH) in food are outlined with special reference to methods based on the outcome of international collaborative trials. Potential PAH contamination routes of food are reviewed and illustrated by relevant recent literature data.Research for PAH in foods most frequently focusses on benzo(a)pyrene and consequently the majority of cited data also

H. A. M. G. Vaessen; P. L. Schuller; A. A. Jekel; A. A. M. M. Wilbers

1984-01-01

168

The Infrared Spectroscopy of Neutral Polycyclic Aromatic Hydrocarbon Clusters  

NASA Astrophysics Data System (ADS)

The mid-infrared spectra of neutral homogeneous polycyclic aromatic hydrocarbon (PAH) clusters have been computed using density functional theory including an empirical correction for dispersion. The C-H out-of-plane bending modes are redshifted for all the clusters considered in this work. The magnitude of the redshift and the peak broadening are dependent on PAH size, shape, and on the PAH arrangement in the cluster.

Ricca, Alessandra; Bauschlicher, Charles W., Jr.; Allamandola, Louis J.

2013-10-01

169

Photolysis of polycyclic aromatic hydrocarbons adsorbed on simulated atmospheric particulates  

Microsoft Academic Search

Fifteen polycyclic aromatic hydrocarbons (PAH) adsorbed on silica gel, alumina, fly ash, and carbon black were photolyzed in order to study their atmospheric fate. Photolytic half-lives for these particle-bound PAH were found to be highly dependent on the substrate to which they were adsorbed. On silica gel and alumina, PAH showed a wide range of photolytic half-lives, indicating a relationship

Thomas D. Behymer; Ronald A. Hites

1985-01-01

170

Screening of ectomycorrhizal fungi for degradation of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Ectomycorrhizal fungi belonging to 16 species (27 strains) were tested for their ability to degrade polycyclic aromatic hydrocarbons\\u000a (PAHs): phenanthrene, chrysene, pyrene and benzo[a]pyrene. Cultivated on a complex liquid medium, most of the fungi tested were able to metabolise these compounds. Approximately\\u000a 50% of the benzo[a]pyrene was removed by strains of Amanita excelsa, Leccinum versipelle, Suillus grevillei, S. luteus, and

A. Braun-Lüllemann; A. Hüttermann; A. Majcherczyk

1999-01-01

171

Kinetics of biodegradation of mixtures of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

The kinetics of biodegradation of polycyclic aromatic hydrocarbons (PAHs) by a mixed culture were determined in a creosote-contaminated soil and in a pristine soil. A competitive-inhibition model was able to represent the kinetics of degradation of PAHs from the creosote-contaminated soil, from the lag phase through to active degradation, but not data from pristine soil with the same PAHs alone

S. K. Lotfabad; M. R. Gray

2002-01-01

172

Atmospheric polycyclic aromatic hydrocarbons in Chicago: Characteristics and receptor modeling  

Microsoft Academic Search

Twenty polycyclic aromatic hydrocarbons (PAHs) were measured by GC and GC\\/MS in 80 ambient samples in Chicago during the year 1990-1991. Using PAHs as fitting components, a chemical mass balance receptor modeling (CMB) was developed to determine source apportionment to the atmospheric PAH and PM10 concentration in Chicago. The CMB modeling for PAHs found that coke ovens, gasoline engine vehicles,

Khalili

1992-01-01

173

Polycyclic aromatic hydrocarbons (PAHs) in livers of California sea otters  

Microsoft Academic Search

Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were measured in livers of 81 adult female sea otters collected along the California coast in 1992–2002. Concentrations of ?PAHs in livers of sea otters were in the range of 588–17400ng\\/g lipid wt (mean: 3880ng\\/g, lipid wt). On a wet weight basis, the concentrations ranged from 17 to 1430ng\\/g (mean: 146ng\\/g). Overall, di-

Kurunthachalam Kannan; Emily Perrotta

2008-01-01

174

QSARs for aromatic hydrocarbons at several trophic levels.  

PubMed

Quantitative structure-activity relationships (QSARs) with aromatic hydrocarbons were obtained. Biological response was measured by acute toxicity of several aquatic trophic levels. The chemicals assayed were benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, isopropylbenzene, n-propylbenzene, and butylbenzene. Acute toxicity tests were carried out with Scenedesmus quadricauda, as representative of primary producers; Daphnia spinulata, a zooplanctonic cladoceran; Hyalella curvispina, a benthic macroinvertebrate; and Bryconamericus iheringii, an omnivorous native fish. The EC50 or LC50 was calculated from analytical determinations of aromatic hydrocarbons. Nonlinear regression analysis between the logarithm of the octanol-water partition coefficient (log Kow) of each compounds and the toxicity end points was performed. QSARs were positively related to increases in log Kow at all trophic levels. Intertaxonomic differences were found in comparisons of algae with animals and of invertebrates with vertebrates. We observed that these differences were not significant with a log Kow higher than 3 for all organisms. Aromatic hydrocarbons with log Kow values of less than 3 showed different toxicity responses, with algae more resistant than fish and invertebrates. We concluded that this was a result of the narcotic mode of action related to liposolubility and the ability of the compound to reach its target site in the cell. The bioconcentration factor (BCF) achieved to start nonpolar narcosis fell almost 1 order of magnitude below the BCF expected from the log Kow. Predicted critical body residues for nonpolar narcosis ranged between 2 and 1 mM. PMID:16528686

Di Marzio, Walter; Saenz, Maria Elena

2006-04-01

175

Mutagenic and carcinogenic properties of polycyclic aromatic hydrocarbons.  

PubMed Central

The rapid development of the chemical industry, combustion of fossil fuels, and smoking of tobacco have resulted in contact of the general population with benzo(a)pyrene and other carcinogenic aromatic hydrocarbons. Persons especially at risk occupationally are those engaged in thermal processing of oil shale, coal, and heavy residual petroleum. It has been shown that polycyclic aromatic hydrocarbons require metabolic activation before they can act as mutagens or carcinogens. This metabolic activation results from interaction with microsomal enzymes present in many body cells, yielding reactive epoxides which react with DNA and produce mutations in the count frame shift or participate in covalent bounding. While opinions differ regarding the relative role of these processes in mutagenesis, considerable evidence exists which links mutagenesis and carcinogenesis. Metabolites of the polycyclic aromatic hydrocarbons which are carcinogenic are usually mutagenic, which supports the hypothesis that damage to chromosomes plays an important role in carcinogenesis. These facts open the possibility to monitoring the spread of carcinogenic substances in the biosphere by relatively simple tests whose endpoint is mutagenesis.

Pashin, Y V; Bakhitova, L M

1979-01-01

176

Aromaticity of hydrocarbon fuels by carbon-13 NMR, a high field approach  

SciTech Connect

During combustion of hydrocarbon fuels aromatic components are known to produce soot deposits that could significantly reduce the life span of turbine engines. Aromatic content affects other physical properties of fuels as well. Therefore, it is important to have an accurate measurement of this quantity in order to predict fuel characteristics required in current and future turbine engines. Currently the FIA test is operator intensive, time consuming and reliable within {plus minus}2%. Efforts have been to signficantly reduce analysis time and error over current techniques. Past C13 methods either emphasize gated decoupling and relaxation reagents, or haven't compared their results with standard samples. The authors have studied aromatic and aliphatic content of known composition samples as well as characteristic field samples. Normal experimental parameters were optimized and data using various decoupling methods were compared. Aromaticity values as affected by experimental parameters as well as relaxation and NOE data on synthetic and field samples will be presented. Results provide reproducible aromaticity values within 0.5% on samples ranging from 1 to 20% aromatic.

Dinges, W.L.; Utermoehlen, C.M. (United States Air Force Academy, CO (United States)); Butler, R.D. (Aero Propulsion and Power Laboratory, Wright-Patterson Air Force Base, OH (United States))

1990-08-01

177

The origin of the polycyclic aromatic hydrocarbons in meteorites  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) in C1 and C2 Carbonaceous Chondrites appear to be the product of a high-temperature synthesis. This observation counters a prevailing view that PAHs in meteorites are a thermal alternation product of preexisting aliphatic compounds, which in turn required the presence of low-temperature mineral phases such as magnetite and hydrated phyllosilicates for their formation. Such a process would necessarily lead to a more low-temperature assemblage of PAHs, as many low-temperature minerals and compounds are extant in meteorites. Ivuna, a C1 carbonaceous chondrite, has been shown to contain abundant amounts of the three-ring PAHs phenanthrene/anthracene, but no detectable levels of the two- and four-ring PAHs naphthalene and pyrene/fluoranthene. Ivuna and other C1 carbonaceous chondrites are known to have been extensively altered by water. The aqueous solubities of PAHs indicate that some PAHs would have been mobilized during the aqueous alteration phase in meteorite parent bodies. Model geochromatography experiments using crushed serpentine or beach sand as the solid phase and water for elution suggest that the complete separation of two, three, and four-ring PAHs could be expected to occur in the parent body of C1 carbonaceous chondrites. It is proposed that aqueous fluids driven by heat in the parent body of Ivuna migrated from the interior to the surface, in the process transporting, separating and concentrating PAHs at various zones in the parent body. The presence of indigenous PAHs and absence of indigenous amino acids in the H4 ordinary chondrite Forest Vale provides support for the contention that different processes and environments contributed to the synthesis of the organic matter in the solar system.

Wing, Michael R.; Bada, Jeffrey L.

1991-09-01

178

Pyrolysis of coals loaded with polycyclic aromatic hydrocarbons  

SciTech Connect

The relative simplicity of pyrolysis offers significant advantages as a coal conversion approach. However, char yields are typically high and volatile products are generally distributed between low value light hydrocarbons and tars that can be very difficult to upgrade. Consequently, the pyrolysis of coals under conditions that would produce larger yields of condensible and readily upgradable hydrocarbons is clearly a desirable goal, and the literature contains many examples of approaches to augmenting pyrolysis yields. For this reason, it is desirable that additional efforts be conducted as much as possible in light of what is known about the mechanism of volatiles production. In order that the loading with aromatics be an effective pretreatment, the reaction conditions must allow for an opportunity for the aromatics to react with the coal before they are simply devolatilized. Liquefaction and coking provide ample opportunity for reactions between the added aromatics and the coal while pyrolysis conditions generally do not favor such interactions. In this paper the authors report their efforts at determining the range of conditions under which loading of coals with PCAH may result in beneficial effects during pyrolysis.

Malhotra, R.; St. John, G.; Tse, D.S.; McMillen, D.F. (SRI International, Menlo Park, CA (USA))

1988-01-01

179

Production of aromatics-rich gasoline with low benzene content  

SciTech Connect

This patent describes a fixed bed process for the alkylation of reformate comprising C{sub 6{minus}} hydrocarbons to produce high octane gasoline. It comprises: separating a naphtha feedstream by fractionation into a lower boiling fraction comprising iso-C{sub 6} aliphatic hydrocarbon components and a reformer feedstock fraction comprising higher boiling C{sub 6+} aliphatic hydrocarbon components; reforming the reformer feedstock fraction comprising the higher boiling C{sub 6+} aliphatic components in contact with reforming catalyst and under reforming conditions to produce a reformate containing benzene and C{sub 7+} hydrocarbons; separating the reformate into a C{sub 6{minus}}hydrocarbon stream containing benzene and paraffins and a C{sub 7+} hydrocarbon stream; introducing the C{sub 6 {minus}} hydrocarbon stream and alkylating agent into an alkylating zone in contract with acidic metallosilicate catalyst under alkylating condition whereby benzene is alkylate to produce high octane gasoline containing C{sub 7+} aromatic hydrocarbons.

Harandi, M.N.; Owen, H.

1990-12-04

180

Composition, distribution, and characterization of polycyclic aromatic hydrocarbons in soil in Linfen, China  

SciTech Connect

A total of 10 surface soil samples representing the entire area of Linfen City were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons. The total polycyclic aromatic hydrocarbon concentration ranged from 1.1 to 63.7 {mu} g g{sup -1}. Analysis of the sources of contamination revealed that polycyclic aromatic hydrocarbons in the soil were derived from combustion sources. Specifically, the primary source of polycyclic aromatic hydrocarbons was coal combustion, but the samples were also effected to varying degrees by traffic emissions. Furthermore, increased levels of contamination were observed in northeast Linfen due to the distribution of industrial plants.

Fu, S.; Cheng, H.X.; Liu, Y.H.; Xia, X.J.; Xu, X.B. [Chinese Academy of Sciences, Beijing (China)

2009-02-15

181

The formation of Polycyclic Aromatic Hydrocarbons in evolved circumstellar environments  

NASA Astrophysics Data System (ADS)

The formation of Polycyclic Aromatic Hydrocarbons in the circumstellar outflows of evolved stars is reviewed, with an emphasis on carbon stars on the Asymptotic Giant Branch. Evidence for PAHs present in their winds is provided by meteoritic studies and recent observations of the Unidentified Infrared bands. We detail the chemical processes leading to the closure of the first aromatic ring as well as the growth mechanisms leading to amorphous carbon grains. Existing studies on PAH formation in evolved stellar envelopes are reviewed and new results for the modelling of the inner wind of the archetype carbon star IRC+10216 are presented. Benzene, C6H6, forms close to the star, as well as water, H2O, as a result of non-equilibrium chemistry induced by the periodic passage of shocks. The growth process of aromatic rings may thus resemble that active in sooting flames due to the presence of radicals like hydroxyl, OH. Finally, we discuss possible formation processes for PAHs and aromatic compounds in the hydrogen-rich R CrB star, V854 Cen, and their implication for the carriers of the Red Emission and the Diffuse Interstellar Bands.

Cherchneff, I.

2011-03-01

182

Concavity effects on the optical properties of aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

We address the modifications on the ground and excited state properties of polycyclic aromatic hydrocarbons (PAHs) induced by variations of concavity and ?-connectivity. We study three series of PAHs, inspired by experimentally feasible systems, from hydrogen-saturated graphene flakes to concave ``buckybowls'' related to the formation of fullerene C60 and carbon nanotube caps. We work within the framework of Hartree-Fock-based semiempirical methods (AM1 and ZINDO/S), and our results are supported by a generally good agreement with the available data. We see clearly that the interplay between concavity and ?-connectivity shifts the bright optical lines to higher energies, and introduces symmetry-forbidden dark excitations at low energy [1]. These features can be the basis for designing optical properties of novel curved aromatic molecules.[4pt] [1] C. Cocchi et al. submitted (2012).

Caldas, Marilia J.; Cocchi, Caterina; Prezzi, Deborah; Ruini, Alice; Fasolino, Annalisa; Molinari, Elisa

2013-03-01

183

Fluorescence quenching studies of nitrated polycyclic aromatic hydrocarbons.  

PubMed

The analysis of nitrated polycyclic aromatic hydrocarbons (NPAHs) is of great importance because of the mutagenicity and possible carcinogenic activity of these compounds, which are distributed widely in the environment. Nitro-substituents in aromatic compounds are known to quench fluorescence and NPAHs have no intrinsic fluorescence, but they can be determined using their quenching effects on other fluorophores. The quenching effects of several important NPAHs on 1,2,3,4- tetrahydro-1-naphthol,5,6,7,8-tetrahydro-1-naphthol,4-(2-hydroxy-4-sulfo-1-naphthylazo)-2-naphthalene carboxylic acid and 7-amino-4-methyl coumarin have been studied. The singlet emission of these fluorophores is efficiently quenched by all the NPAHs, the quenching following the Stern-Volmer relationship. Quenching constants and the limits of detection and linear ranges of the quenchers have been determined in each case: the limits of detection are ca 1?µm. PMID:20354970

Al-Kindy, Salma M Z; Miller, James N

184

Analysis of the distribution of some polycyclic aromatic hydrocarbons in sediments and suspended matter in the River Seine (France)  

Microsoft Academic Search

Sixteen EPA chosen polycyclic aromatic hydrocarbons (PAH) were studied in the sediments and the suspended matter of the River Seine to determine existing pollution. Analyses were carried out by HPLC with coupled fluorimetric and UV detectors. PAH contents were found to be highly variable depending on many factors such as anthropogenic activities, weather and flow rate of the river, and

D. Ollivon; B. Garban; A. Chesterikoff

1995-01-01

185

Ambient air aerosols, total polycyclic aromatic hydrocarbons (PAHs) for day and night time in the traffic areas of Central Taiwan  

Microsoft Academic Search

Day and night time ambient air samples from a traffic intersection were collected using Noll Rotary Impactor (NRI) and micro?orifice uniform deposited impactor (MOUDI) samplers from June 1997 to August 1997 in central Taiwan to characterize the atmospheric particle mass, total Polycyclic aromatic hydrocarbons (PAHs) size distribution and total PAHs content for the day and night period in a traffic

1999-01-01

186

The effect of aromatization on the isotopic compositions of hydrocarbons during early diagenesis.  

PubMed

Polycyclic aromatic hydrocarbons with varying degrees of aromatization were isolated from the Eocene Messel Shale (Rheingraben, Germany). The high abundances of these compounds and their structural resemblances to cyclic triterpenoid lipids are consistent with derivation from microbial rather than thermal processes. Compounds structurally related to oleanane contain from five to nine double bonds; those within a series of aromatized hopanoids contain from three to nine. All are products of diagenetic reactions that remove hydrogen or methyl groups, and, in several cases, break carbon-carbon bonds to open rings. Aromatized products are on average depleted in 13C relative to possible precursors by l.2% (range: l.5% enrichment to 4% depletion, n = 9). The dependence of 13C content on the number of double bonds is not, however, statistically significant and it must be concluded that there is no strong evidence for isotopic fractionation accompanying diagenetic aromatization. Isotopic differences between series (structures related to ursane, des-A-ursane, des-A-lupane, des-A-arborane, and possibly, des-A-gammacerane are present) are much greater, indicating that 13C contents are controlled primarily by source effects. Fractionations due to chromatographic isotope effects during HPLC ranged from 0.1 to 2.8%. PMID:11539437

Freeman, K H; Boreham, C J; Summons, R E; Hayes, J M

1994-01-01

187

Stability of multiply charged clusters of polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

The stability of multiply charged clusters of polycyclic aromatic hydrocarbons (PAHs) is theoretically investigated. We propose a new model (stacked structure model) for fragmentation of PAH clusters. The appearance size, a minimum cluster size such that the cluster remains stable when multiply ionized, is calculated by our new model as well as by the conventional liquid drop model. The appearance sizes for doubly charged clusters of anthracene and coronene calculated by the two models are found to be much smaller than those observed in the experiments. Possible reasons for the discrepancy are discussed.

Nakamura, Masato; Ichimura, Atsushi

2013-09-01

188

Polycyclic aromatic hydrocarbon-DNA adduct formation in prostate carcinogenesis  

PubMed Central

The evidence for polycyclic aromatic hydrocarbons (PAH) playing a role in prostate carcinogenesis comes mainly from associations between reported PAH exposures and prostate cancer in epidemiologic studies. Associations between prostate cancer and DNA repair genotypes and phenotypes have also been reported, lending further credence to a PAH-induced carcinogenesis pathway in prostate cancer. Recent work that demonstrates the human prostate has metabolic enzyme activity necessary for PAH activation and will form DNA adducts upon exposure to PAH further supports PAH carcinogenesis. We have demonstrated the presence of PAH-DNA adducts in prostate cancer cases, but further validation of this biomarker as a carcinogenic agent in human prostate is needed.

Rybicki, Benjamin A.; Nock, Nora L.; Savera, Adnan T.; Tang, Deliang; Rundle, Andrew

2006-01-01

189

Determination of polycyclic aromatic hydrocarbons in commercial roasted coffee beans  

Microsoft Academic Search

This study was conducted to investigate the presence of 7 polycyclic aromatic hydrocarbons (PAHs) [benzo[a]anthracene (BaA), chrysene (CRY), benzo[b] fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a] pyrene (BaP), dibenzo[a,h]anthracene (DahA), benzo [g,h,i]perylene (BghiP)] in roasted coffee beans from Korean market. In this study, the method for sample preparation involved liquid-liquid extraction\\u000a after saponification with potassium hydroxide (KOH), followed by solid-phase extraction (SPE).

Kyueun Lee; Han-Seung Shin

2010-01-01

190

Pyrolytic formation of polycyclic aromatic hydrocarbons from sesquiterpenes.  

PubMed

The products of the pyrolysis of four sesquiterpenes, ?-caryophyllene, ?-cedrene, longifolene and valencene, have been examined. Pyrolysis was carried out at 300, 400 and 500°C, the products determined by GC-MS and then examined for similarities and differences using multivariate data analysis. Analysis showed that longifolene was most resistant and caryophyllene least resistant to pyrolysis with cedrene and valencene occupying intermediate positions. While the compounds were largely unchanged at 300°C, polycyclic aromatic hydrocarbons (PAHs) were major components of the pyrolysates at 400 and 500°C. No less than nine of the 16 EPA priority pollutants were present in the pyrolysates at the higher temperatures. PMID:22953860

Francis, George W; Christy, Alfred A; Oygarden, Jostein

2012-06-28

191

Oxidation of polycyclic aromatic hydrocarbons catalyzed by soybean peroxidase  

Microsoft Academic Search

Soybean peroxidase (SBP) catalyzes the oxidation of a variety of polycyclic aromatic hydrocarbons (PAHs) in the presence of\\u000a water-miscible organic cosolvents, including acetonitrile, tetrahydrofuran, and dimethylformamide (DMF). Oxidation was optimal\\u000a at pH 2.0–2.5, with substantially lower reactivity at pH 1.5 as well as at pH > 3.0. Despite the low pH activity optimum,\\u000a SBP had an observed half-life of 120

Jennifer J. Kraus; Inmar Z. Munir; James P. McEldoon; Douglas S. Clark; Jonathan S. Dordick

1999-01-01

192

Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils  

PubMed Central

This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.

Lau, E. V.; Gan, S.; Ng, H. K.

2010-01-01

193

Occurrence of chlorinated polynuclear aromatic hydrocarbons in tap water  

SciTech Connect

Organic compounds in tap waters were extracted by a modified continuous liquid-liquid extractor and analyzed by computerized gas chromatography/mass spectrometry using a fused silica capillary column. The results indicate the presence of monochlorinated derivatives of naphthalene, dibenzofuran, fluorene, fluorenone, phenanthrene, and fluoranthene and dichlorinated derivatives of naphthalene, phenanthrene, and fluoranthene. The parent polynuclear aromatic hydrocarbons (PAHs) and their oxygenated derivatives such as fluorenone and anthraquinone were also found. It was demonstrated that chlorinated PAHs (Cl-PAHs) were really present in tap waters at 10/sup -1/-10/sup -2/ ng/L levels.

Shiraishi, H.; Pilkington, N.H.; Otsuki, A.; Fuwa, K.

1985-07-01

194

Fate of polycyclic aromatic hydrocarbons during composting of oily sludge.  

PubMed

In order to assess the effectiveness of aerobic degradation with emphasis on the 16 U.S. EPA priority polycyclic aromatic hydrocarbons (PAH), oily sludge generated by a dissolved air flotation flocculation unit of a wastewater treatment plant in a petroleum refinery was amended with remediated oil-contaminated soil and non-mature garden waste compost 40:40:20 (wet weight) respectively. About 21 t of the mixture with a top-layer formed by 30 cm of remediated soil was treated in a 28 m3 air-forced reactor. The PAH concentration was monitored for 370 days. In the top-layer, a reduction of 88 % of the total extractable PAH was measured at day 62 and a final reduction of 93% at day 370. In the mixture, a reduction of 72% in total PAH was measured at day 62, followed by fluctuation in concentration with a final measured reduction of 53% at day 370. The analysis of individual PAH in the mixture suggested that volatilization and biodegradation are the main mechanisms responsible for the reduction of 2 ring PAH and 3-4 ring PAH, respectively. Fluctuation of 5-6 ring PAH concentrations with increase observed at the end of the period might result from a combination of the following: (i) sequestration of large PAH in the organic matrix (reducing bioavailability, biodegradability and eventually, extractability) and desorption as composting progresses; (ii) heterogeneous distribution of the stable large PAH in the mixture, thus affecting sampling. It was concluded that one-time composting in static-aerated biopiles with organic amendments as the sole strategy to treat oily sludge is very effective in reducing the content of 2-4 ring PAH, but it is not effective in reducing the content of 5-6 ring PAHs, even after a relatively long time span (370 d). The concentrations measured in the remediated soil that formed the top layer after 62 days of composting suggests that further relevant reduction of residual PAH (89% of total PAH and 69% of 5-6 ring PAH) can be obtained if the contaminated masses are exposed to a second thermophilic phase. This could be achieved by adding new easily biodegradable organic amendments to the contaminated masses after some months of composting, remixing and composting again for a minimum additional period of 2 months. PMID:18610544

Kriipsalu, M; Marques, M; Hogland, W; Nammari, D R

2008-01-01

195

Microbial abundance and degradation of polycyclic aromatic hydrocarbons in soil  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs) are a group of highly lipophilic chemicals that are generally formed during combustion, pyrolysis and pyrosynthesis of organic matter and are present ubiquitously in the urban environment as pollutants in very small quantities. The objective of the present study was to determine the activity of indigenous microbial populations of hazardous waste sites, their degree of adaptation, their ability to degrade toxic PAHs, and to study the potentials of different indigenous microbes to degrade the following selected PAHs from the polluted soil environment. PAHs selected for the study were anthracene, phenanthrene, chrysene, pyrene and fluoranthene. In this study, the indigenous contaminated soil populations were effective in removing the hydrocarbons and returning the soil to productivity. The biodegradation of PAHs in the selected soil was due to PAH degrader present in the bacterial as well as fungal communities. 13 refs., 2 tabs.

Mahmood, S.K.; Rao, P.R. (Osmania Univ., Hyderabad (India))

1993-04-01

196

Effects of co-occurring aromatic hydrocarbons on degradation of individual polycyclic aromatic hydrocarbons in marine sediment slurries  

SciTech Connect

Rates of polycyclic aromatic hydrocarbon (PAH) degradation and mineralization were influenced by preexposure to alternate PAHs and a monoaromatic hydrocarbon at relatively high (100 ppm) concentrations in organic-rich aerobic marine sediments. Prior exposure to three PAHs and benzene resulted in enhanced (/sup 14/C)naphthalene mineralization, while (/sup 14/C)anthracene mineralization was stimulated only by benzene and anthracene preexposure. Preexposure of sediment slurries to phenanthrene stimulated the initial degradation of anthracene. Prior exposure to naphthalene stimulated the initial degradation of phenanthrene but had no effect on either the initial degradation of mineralization of anthracene. For those compounds which stimulated (/sup 14/C)anthracene of (/sup 14/C)naphthalene mineralization, longer preexposures (2 weeks) to alternative aromatic hydrocarbons resulted in an even greater stimulation response. Enrichment with individual PAHs followed by subsequent incubation with one or two PAHs showed no alteration in degradation patterns due to the simultaneous presence of PAHs. The evidence suggests that exposure of marine sediments to a particular PAH or benzene results in the enhanced ability of these sediments to subsequently degrade that PAH as well as certain other PAHs. The enhanced degradation of a particular PAH after sediments have been exposed to it may result from the selection and proliferation of specific microbial populations capable of degrading it.

Bauer, J.E.; Capone, D.G.

1988-07-01

197

Polycyclic Aromatic Hydrocarbons as Plausible Prebiotic Membrane Components  

NASA Astrophysics Data System (ADS)

Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C6-C10 fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane.

Groen, Joost; Deamer, David W.; Kros, Alexander; Ehrenfreund, Pascale

2012-08-01

198

Polycyclic aromatic hydrocarbons as plausible prebiotic membrane components.  

PubMed

Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C(6)-C(10) fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane. PMID:22798228

Groen, Joost; Deamer, David W; Kros, Alexander; Ehrenfreund, Pascale

2012-07-15

199

Aerosol formation studies on aromatic hydrocarbons in the EUPHORE outdoor simulation chamber  

NASA Astrophysics Data System (ADS)

The present work is an experimental study on the formation of secondary organic aerosol during the photochemical oxidation of aromatic hydrocarbons in an environmental smog chamber under realistic conditions, i.e., low precursor concentrations and natural solar irradiation. A series of newly designed smog chamber irradiations were performed in the EUPHORE chambers (Valencia, Spain) in which concentration levels of precursors were chosen to be near to those measured in urban atmosphere. The objective was to determine the aerosol formation potential of aromatic hydrocarbons under conditions that are prevalent in the urban atmosphere. The obtained experimental results on aerosol yields and organic threshold for aerosol formation have been used to determine the parameters controlling aerosol formation from toluene, benzene, p-xylene and 1,3,5-trimethylbenzene photo-oxidation and to investigate the possible reaction channels responsible for the formation of condensable material. The comparison of the aerosol yields obtained in the present work with previous data indicates that the NOx content in the aromatic system has a strong influence on the aerosol formation during the photochemical oxidation of aromatic hydrocarbons. Nitrogen oxides, and in particular NO, are seen as key species controlling particle formation during the photochemical oxidation of these species; this contrasts with previous work where the aerosol formation capacity was attributed to the presence or the absence of ozone in the system. The results show that there is a competition between OH and NO_3 radicals to form secondary products that act as aerosol precursors, and therefore a dependence of aerosol formation on the NOx content in the system is observed.

Wirtz, K.; Martin-Reviejo, M.; Borras, E.

2003-04-01

200

Correlation of Cardiotoxicity Mediated by Halogenated Aromatic Hydrocarbons to Aryl Hydrocarbon Receptor Activation  

Microsoft Academic Search

Halogenated aromatic hydrocarbons (HAHs) are ubiquitous environmental contaminants that have been characterized as potent toxicants and carcinogens. Many of these compounds, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), elicit diverse biological effects in laboratory animals such as promo- tion of carcinogenesis, immune suppression, and impairment of reproduction. Much of the biological risk of these compounds, including that of TCDD, has been correlated with their

Scott E. Heid; Mary K. Walker; Hollie I. Swanson

2001-01-01

201

Aromatic hydrocarbons in New York Bight polychaetes: ultraviolet fluorescence analyses and gas chromatography/gas chromatography-mass spectrometry analyses  

SciTech Connect

Polychaetes collected from New York Bight sediments near sewage sludge and harbor dredge spoil drump sites contained a series of diaromatic-tetracyclic hydrocarbons of apparent triterpenoid origin. Microbial processes in sewage sludge are a likely source of these compounds. These octahydrochrysenes were much more abundant in the polychaetes than were the fossil fuel and combustion-derived polycyclic aromatic hydrocarbons which were found in the sediments, presumably because they are more available for biological uptake. If the polychaetes had been analyzed only by the spectrofluorometric techniques often used for screening samples for petroleum contamination, then grossly inaccurate results for aromatic hydrocarbon content would have been obtained. Therefore, UV fluorescence must be used in a hierarchical approach, with more sophisticated procedures available to verify the petrogenic nature of the hydrocarbons. 20 references, 4 figures, 2 tables.

Farrington, J.W.; Wakeham, S.G.; Livramento, J.B.; Tripp, B.W.; Teal, J.M.

1986-01-01

202

MTBE and aromatic hydrocarbons in North Carolina stormwater runoff.  

PubMed

A total of 249 stormwater samples were collected from 46 different sampling locations in North Carolina over an approximate 1-year period and analyzed to identify land use types where fuel oxygenates and aromatic hydrocarbons may be present in higher concentrations and at greater frequency. Samples were analyzed by gas chromatography-mass spectrometry in ion selective mode to achieve a quantitation limit of 0.05 microg/l. m-,p-Xylene and toluene were detected in over half of all samples analyzed, followed by MTBE: o-xylene: 1,3,5-trimethylbenzene: ethylbenzene; and 1,2,4-trimethylbenzene. Benzene, DIPE, TAME and 1,2,3-trimethylbenzene were detected in < 10% of the samples analyzed. Median contaminant concentrations (when detected) varied from 0.07 microg/l for ethylbenzene to 0.11 microg/l for toluene. All of the locations with significantly higher contaminant concentrations were associated with direct runoff from a gas station or discharge of contaminated groundwater from a former leaking underground storage tank. For all of the aromatic hydrocarbons, the maximum observed contaminant concentrations were over an order of magnitude lower than current drinking water standards. PMID:11996377

Borden, Robert C; Black, David C; McBlief, Kathleen V

2002-01-01

203

Thermal neutron cross-section libraries for aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Solid phases of aromatic hydrocarbons, such as benzene, toluene, mesitylene and a 3:2 mixture by volume of mesitylene and toluene, were studied as potential moderator materials for a cold neutron source. Existing information on the (lattice) translational and rotational modes of the different molecular species was used to produce generalized frequency spectra; the latter included the internal vibrational modes which in turn involved the analysis of the weights of the different modes. Cross-section libraries were generated in ENDF and ACE formats for hydrogen bounded in those materials at several temperatures, and were used in Monte Carlo calculations to analyze their neutron production compared with standard cryogenic materials like liquid hydrogen and solid methane, the best moderators in terms of cold neutron production. In particular, cross-section libraries were generated at 20 K, which is a typical operating temperature for the majority of the existing cold neutron sources. It was found that those aromatic hydrocarbons produce neutron spectra which are slightly warmer than that of solid methane while presenting a high resistance to radiation, conforming in this way a new and advantageous alternative to traditional moderator materials.

Cantargi, F.; Granada, J. R.

2010-08-01

204

Polycyclic aromatic hydrocarbons (PAHs) in livers of California sea otters.  

PubMed

Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were measured in livers of 81 adult female sea otters collected along the California coast in 1992-2002. Concentrations of summation operatorPAHs in livers of sea otters were in the range of 588-17400ng/g lipid wt (mean: 3880ng/g, lipid wt). On a wet weight basis, the concentrations ranged from 17 to 1430ng/g (mean: 146ng/g). Overall, di- and tri-cyclic aromatic hydrocarbons, namely, naphthalene, fluorene, phenanthrene/anthracene, and acenaphthylene, were the predominant compounds found in the livers. Although petroleum-related sources appear to be the major contributors to PAH exposure in sea otters, exposure sources varied by geographical sub-regions. Dibenz[a,h]anthracene was found to comprise a significant proportion of the summation operatorPAH concentrations in sea otters from the northern sub-region of the study area. No significant difference existed in the concentrations of summation operatorPAHs among sea otters that died from infectious diseases, emaciation, and noninfectious causes. Concentrations of summation operatorPAHs in livers of sea otters decreased significantly from 1992 to 2002. Because of the rapid metabolism of PAHs in marine mammals such as sea otters, further studies examining the association of PAHs with health effects should determine hydroxylated metabolites in livers. PMID:18177687

Kannan, Kurunthachalam; Perrotta, Emily

2008-01-03

205

Polycyclic aromatic hydrocarbons in Australian coals. III. Structural elucidation by proton nuclear magnetic resonance spectroscopy  

Microsoft Academic Search

The molecular structures of a number of tetra- and pentacyclic aromatic hydrocarbons present in extracts of Victorian brown coal have been unambiguously established by ¹H-NMR. The determined structures support the hypothesis that these polycyclic aromatic hydrocarbons (PAHs) are diagenetically derived from triterpenoid precursors based on the oleanane, ursane and lupane skeletons. The occurrence of diastereoisomerism in these PAHs has been

A. L. Chaffee; C. J. R. Fookes

1988-01-01

206

The Application of Adsorption to Remove Aromatic Hydrocarbons from Flue Gas  

Microsoft Academic Search

Aromatic hydrocarbons recommended as the persistent organic pollutants distribute widely in atmospheric environment. PAHs (polycyclic aromatic hydrocarbons) and BTEX (benzene, toluene, ethyl benzene and p-xylene) are harmful to the environment and health of people, since they are the precursors of photochemical oxidants and agents of the acid rain, and have high degree of mutagenicity and carcinogenicity. Among the purifying technology

Hongcang Zhou; Huaxia Cai; Hongbin Xue; Jiangang Lu; Yuanyuan Song; Cuicui Zhang

2010-01-01

207

Sources and Fate of Polycyclic Aromatic Hydrocarbons in Ambient Air of Urban and Rural Croatian Sites  

Microsoft Academic Search

Atmospheric concentrations of nineteen polycyclic aromatic hydrocarbons (PAHs) were determined in the particulate and vapour phases of samples collected during 24 hours in winter and summer 1990 from croatian urban, industrial and rural sites.An analytical procedure is described for a comprehensive determination of polycyclic aromatic hydrocarbons in air samples based on aerosol filtration through glass fiber filters and vapour phase

I. Eškinja; Z. ŠOlji?; S. Švel-Cerove?ki; M. Eškinja; V. Šojat

1996-01-01

208

Oxidative transformations of polycyclic aromatic hydrocarbons adsorbed on coal fly ash  

SciTech Connect

Polycyclic aromatic hydrocarbons adsorbed onto coal fly ash were found to be stabilized against photochemical decomposition. However, a number of adsorbed polycyclic aromatic hydrocarbons will spontaneously oxidize in the absence of light, with those compounds containing a benzylic carbon being particularly susceptible. The decomposition rate appears to be fly ash-dependent.

Korfmacher, W.A. (Univ. of Illinois, Urbana); Natusch, D.F.S.; Taylor, D.R.; Mamantov, G.; Wehry, E.L.

1980-02-15

209

Some Aspects of the Measurement of Polycyclic Aromatic Hydrocarbons in Aqueous Solution  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) are formed during pyrolysis or incomplete combustion of organic materials. As a result of an increasing public concern about the contamination of the environment, polycyclic aromatic hydrocarbons are extensively studied compounds. Because PAH are present in effluents from coal firing and advanced coal conversion processes, methods are studied in our laboratory to quantify PAH-emissions.It is known

F. Janssen; J. Kanij

1982-01-01

210

Evidence for the adsorption of nitrated polycyclic aromatic hydrocarbons by tree bark  

Microsoft Academic Search

It has been previously demonstrated that polycyclic aromatic hydrocarbons (PAH) are adsorbed onto tree bark and that bark may in fact be used as a passive sampler for these compounds. It is now demonstrated that by suitable modification of this methodology nitrated polycyclic aromatic hydrocarbons (nitro-PAH) may also be detected in bark. Bark samples were taken from urban locations in

David S. Douce; Malcolm R. Clench; Michael Cooke; Junde Wang

1997-01-01

211

Oxidative transformations of polycyclic aromatic hydrocarbons adsorbed on coal fly ash  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons adsorbed onto coal fly ash were found to be stabilized against photochemical decomposition. However, a number of adsorbed polycyclic aromatic hydrocarbons will spontaneously oxidize in the absence of light, with those compounds containing a benzylic carbon being particularly susceptible. The decomposition rate appears to be fly ash-dependent.

W. A. Korfmacher; D. F. S. Natusch; D. R. Taylor; G. Mamantov; E. L. Wehry

1980-01-01

212

Particulate Polycyclic Aromatic Hydrocarbons and Their Nitrated Derivatives in Three Cities in Liaoning Province, China  

Microsoft Academic Search

Airborne particulates were collected in nine size fractions by using Andersen low-volume air samplers in the cities of Shenyang, Fushun, and Tieling, Liaoning Province, in northeast China, during the period from July 2001 through December 2003. Nine polycyclic aromatic hydrocarbons (PAHs) and seven nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined. The mean concentrations of the sums of

Tetsuyuki Hattori; Ning Tang; Kenji Tamura; Akari Hokoda; Xiaoyang Yang; Kazuhiko Igarashi; Michihiro Ohno; Yumi Okada; Takayuki Kameda; Akira Toriba; Kazuichi Hayakawa

2007-01-01

213

Polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in urban air particulates and their relationship to emission sources in the Pan–Japan Sea countries  

Microsoft Academic Search

Airborne particulates were collected in seven cities in the Pan–Japan Sea countries, Shenyang (China), Vladivostok (Russia), Seoul (South Korea), Kitakyushu, Kanazawa, Tokyo and Sapporo (Japan), in winter and summer from 1997 to 2002. In addition, particulates from domestic coal-burning heaters and diesel engine automobiles were collected in Shenyang and Kanazawa, respectively. Nine polycyclic aromatic hydrocarbons (PAHs) and four nitropolycyclic aromatic

Ning Tang; Tetsuyuki Hattori; Rina Taga; Kazuhiko Igarashi; Xiaoyang Yang; Kenji Tamura; Hitoshi Kakimoto; Vasiliy F. Mishukov; Akira Toriba; Ryoichi Kizu; Kazuichi Hayakawa

2005-01-01

214

Assessment of polycyclic aromatic hydrocarbons (PAHs) pollution in soil of suburban areas in Tianjin, China.  

PubMed

Soil contamination with polycyclic aromatic hydrocarbons is an increasing problem and has aroused more and more concern in many countries, including China. In this study, representative soil samples (n = 87) of suburban areas in Tianjin (Xiqing, Dongli, Jinnan, Beichen) were evaluated for 16 polycyclic aromatic hydrocarbons. Surface soil samples were air-dried and sieved. Microwave assisted extraction was used for polycyclic aromatic hydrocarbons preparation prior to analysis with gas chromatography-mass spectrometry. The total concentrations of tested polycyclic aromatic hydrocarbons in Xiqing, Dongli, Jinnan, Beichen ranged in 58.5-2,748.3, 36.1-6,734.7, 58.5-4,502.5, 29.7-852.5 ng/g and the averages of total concentration of polycyclic aromatic hydrocarbons were 600.5, 933.6, 640.8, 257.3 ng/g, respectively. Spatial variation of polycyclic aromatic hydrocarbons in soil was illustrated; Pollution status and comparison to other cities were also investigated. Serious polycyclic aromatic hydrocarbons soil pollution was found in Dongli district, on the contrary, Bap in most sites in Beichen did not exceed relative standards and most sites in Beichen should be classified as non-contaminated soil. Principal component analysis was used to identify the possible sources of different districts. It turned out that coal combustion still was the most important sources in three districts except Beichen. Coking, traffic, cooking, biomass combustion also accounted for polycyclic aromatic hydrocarbons pollution to certain extent in different districts. These data can be further used to assess the health risk associated with soils polluted with polycyclic aromatic hydrocarbons and help local government find proper way to reduce polycyclic aromatic hydrocarbons pollution in soils. PMID:20411238

Lv, Jungang; Shi, Rongguang; Cai, Yanming; Liu, Yong

2010-04-22

215

Polycyclic aromatic hydrocarbons from the co-pyrolysis of catechol and propyne  

Microsoft Academic Search

In order to investigate C3 species as potential participants in aromatic-ring-growth reactions of polycyclic aromatic hydrocarbons (PAH) from solid fuels, we have performed pyrolysis experiments in an isothermal laminar-flow reactor (at temperatures, 700–1000°C; residence time, 0.3s) with the C3 hydrocarbon propyne, the model fuel catechol (representative of aromatic moieties in coal and biomass), and with propyne and catechol together (in

Nimesh B. Poddar; Shiju Thomas; Mary J. Wornat

2011-01-01

216

Assessment of Total Aromatic Hydrocarbons, Aliphatic and Polycyclic Aromatic Hydrocarbons in Surface Sediment and Fish from the Gulf of Tunis (Tunisia)  

Microsoft Academic Search

This investigation represents the extensive study of the spatial distribution and sources of hydrocarbons in the Gulf of Tunis. Sediments and fish were sampled within the open sea of the Gulf of Tunis during August 2004. All samples were extracted with organic solvents, separated by silica\\/alumina column chromatography, and analyzed by spectrofluorometry for the determination of total aromatic hydrocarbons (TAH)

Nadia Mzoughi; Lassaad Chouba; Gaëtane Lespes

2010-01-01

217

Biodegradation of Aliphatic and Aromatic Hydrocarbons by Nocardia sp. H17-1  

Microsoft Academic Search

We investigated the biodegradation of hydrocarbon components by Nocardia sp. H17-1 and the catabolic genes involved in the degradation pathways of both aliphatic and aromatic hydrocarbons. After 6 days of incubation, the aliphatic and aromatic fractions separated from Arabian light oil were degraded 99.0 ± 0.1% and 23.8 ± 0.8%, respectively. Detection of the catabolic genes involved in the hydrocarbon

Kyung-Hwa Baek; Byung-Dae Yoon; Hee-Mock Oh; Hee-Sik Kim; In-Sook Lee

2006-01-01

218

Simulated transport of polycyclic aromatic hydrocarbons in artificial streams  

SciTech Connect

A model was constructed to predict the pattern of flow and accumulation of three polycyclic aromatic hydrocarbons (PAH) (anthracene, naphthalene, and benzo(a)pyrene) in artificial streams located on the Savannah River Plant near Aiken, South Carolina. Predictions were based upon the premise that the fundamental chemistry of individual PAH contains useful information for predictive purposes. Model processes included volatilization, photolysis, sorption to sediments and particulates, and net accumulation by biota. Simulations of anthracene transport were compared to results of an experiment conducted in the streams. The model realistically predicted the concentration of dissolved anthracene through time and space. Photolytic degradation appeared to be a major pathway of anthracene flux from the streams.

Bartell, S.M.; Landrum, P.F.; Giesy, J.P.; Leversee, G.J.

1981-01-01

219

Photolysis of polycyclic aromatic hydrocarbons adsorbed on simulated atmospheric particulates  

SciTech Connect

Fifteen polycyclic aromatic hydrocarbons (PAH) adsorbed on silica gel, alumina, fly ash, and carbon black were photolyzed in order to study their atmospheric fate. Photolytic half-lives for these particle-bound PAH were found to be highly dependent on the substrate to which they were adsorbed. On silica gel and alumina, PAH showed a wide range of photolytic half-lives, indicating a relationship between structure and photochemical reactivity. However, PAH on environmental substrates such as fly ash and carbon black show similar half-lives for most PAH, indicating a photolytic process that is independent of structure and dependent on the physical and chemical nature of the substrate. In fact, fly ash and carbon black appear to stabilize some PAH; this would facilitate their transport from combustion sources through the atmosphere.

Behymer, T.D.; Hites, R.A.

1985-10-01

220

Emission of polycyclic aromatic hydrocarbons in China by county  

SciTech Connect

Quantitative relationships among social, economic, and climate parameters, and energy consumption for Chinese provinces, provide data for regression models' estimated rates of energy consumption and emission of polycyclic aromatic hydrocarbons (PAHs) by county. A nonlinear model was used for domestic coal combustion with total population and annual mean temperature as independent variables. Linear regression models were utilized for all other types of fuel consumption. Monte Carlo simulation demonstrated that emission factors, rather than the regression modeling, constitute the main source of uncertainty in prediction. Models were validated using available energy data of several northern and southern counties of China from the literature. The total PAHs produced by each county is approximately equivalent to the sum of the total emission from energy, coke, and aluminum production. 25 refs., 8 figs.

Yanxu Zhang; Shu Tao; Jun Cao; Raymond M. Coveney III [Peking University, Beijing (China). Laboratory for Earth Surface Processes, College of Environmental Sciences

2007-02-15

221

NMR shifts for polycyclic aromatic hydrocarbons from first-principles  

NASA Astrophysics Data System (ADS)

We present first-principles, density-functional theory calculations of the NMR chemical shifts for polycyclic aromatic hydrocarbons, starting with benzene and increasing sizes up to the one- and two-dimensional infinite limits of graphene ribbons and sheets. Our calculations are performed using a combination of the recently developed theory of orbital magnetization in solids, and a novel approach to NMR calculations where chemical shifts are obtained from the derivative of the orbital magnetization with respect to a microscopic, localized magnetic dipole. Using these methods we study on equal footing the 1H and 13 shifts in benzene, pyrene, coronene, in naphthalene, anthracene, naphthacene, and pentacene, and finally in graphene, graphite, and an infinite graphene ribbon. Our results show very good agreement with experiments and allow us to characterize the trends for the chemical shifts as a function of system size.

Thonhauser, T.; Ceresoli, Davide; Marzari, Nicola

222

INFRARED SPECTRA OF ISOLATED PROTONATED POLYCYCLIC AROMATIC HYDROCARBON MOLECULES  

SciTech Connect

Gas-phase infrared (IR) spectra of larger protonated polycyclic aromatic hydrocarbon molecules, H{sup +}PAH, have been recorded for the first time. The ions are generated by electrospray ionization and spectroscopically assayed by IR multiple-photon dissociation (IRMPD) spectroscopy in a Fourier transform ion cyclotron resonance mass spectrometer using a free electron laser. IRMPD spectra of protonated anthracene, tetracene, pentacene, and coronene are presented and compared to calculated IR spectra. Comparison of the laboratory IR spectra to an astronomical spectrum of the unidentified IR emission (UIR) bands obtained in a highly ionized region of the interstellar medium provides for the first time compelling spectroscopic support for the recent hypothesis that H{sup +}PAHs contribute as carriers of the UIR bands.

Knorke, Harald; Langer, Judith; Dopfer, Otto [Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin, Hardenbergstrasse 36, D-10623 Berlin (Germany); Oomens, Jos, E-mail: dopfer@physik.tu-berlin.d [FOM Institute for Plasma Physics, Rijnhuizen, P.O. Box 1207, 3430BE Nieuwegein (Netherlands)

2009-11-20

223

Polynuclear aromatic hydrocarbon analysis using the synchronous scanning luminoscope  

NASA Astrophysics Data System (ADS)

12 The Synchronous Scanning Luminoscope (SSL) is a field- portable, synchronous luminescence spectrofluorometer that was developed for on-site analysis of contaminated soil and ground water. The SSL is capable of quantitative analysis of total polynuclear aromatic hydrocarbons (PAHs) using phosphorescence and fluorescence techniques with a high correlation to laboratory data as illustrated by this study. The SSL is also capable of generating benzo(a)pyrene equivalency results, based on seven carcinogenic PAHs and Navy risk numbers, with a high correlation to laboratory data as illustrated by this study. These techniques allow rapid field assessments of total PAHs and benzo(a)pyrene equivalent concentrations. The Luminoscope is capable of detecting total PAHs to the parts per billion range. This paper describes standard field methods for using the SSL and describes the results of field/laboratory testing of PAHs. SSL results from two different hazardous waste sites are discussed.

Hyfantis, George J.; Teglas, Matthew S.; Wilbourn, Robert G.

2001-02-01

224

Accumulation of polycyclic aromatic hydrocarbons in acid sensitive lakes  

SciTech Connect

Polycyclic aromatic hydrocarbon concentrations and fluxes were measured in {sup 210}Pb dated sediment cores taken from nine lakes in four regions identified as susceptible to acidification. Calculated PAH accumulations were compared with historic S emissions, accumulation of sedimentary S, and anthropogenic metal accumulations to determine if PAH could be used as an indicator of combustion-derived sulfate deposition. Comparisons between regions indicated that the Adirondacks have a significantly higher burden of PAH than do northern New England, the northern Great Lakes States, and northern Florida. This difference likely results from significant upwind PAH sources to the Adirondack lakes. Detailed investigation of the largest lake in the study set, Big Moose Lake, indicates that PAH may serve as conservative, combustion indicators in large lakes. In this lake, PAH fluxes and concentrations were significantly correlated with historical S emission rates. These data suggest that PAH measured in sediment cores from large lakes can serve as indicators of past combustion production deposition.

Furlong, E.T.; Cessar, L.R.; Hites, R.A. (Indiana Univ., Bloomington (USA))

1987-11-01

225

Room-temperature phosphorescence of polynuclear aromatic hydrocarbons in cyclodextrins  

SciTech Connect

A new approach for production of phosphorescence at room temperature in fluid solution using microscopically organized media is described. Lumiphors form inclusion complexes inside cyclodextrin molecules and, in the presence of a heavy-atom-containing species, undergo emission from their triplet state. The resulting phosphorescence is intense, spectrally well resolved, and partially insensitive to quenching by dissolved oxygen. Only molecules that physically can enter the cyclodextrin cavity are phosphorescent, which provides considerable selectivity based on lumiphor size. Shapes of analytical calibration curves are similar to those obtained for micelle stabilized room-temperature phosphorescence and are linear over 4 decades. Typical precision is < 10% RSD, with limits of detection in the 10/sup -11/ to 10/sup -13/ M range. Application of the method to the determination of polynuclear aromatic hydrocarbons is discussed. 26 references.

Scypinski, S.; Love, L.J.C.

1984-03-01

226

Application of biotechnology for the biodegradation of polycyclic aromatic hydrocarbons  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs) and their alkyl and nitrated analogs are widely distributed in sediments and aquatic environments. Many PAHs have been shown to exhibit a large variety of biological activities. The goal of this research program are: 1. To isolate microorganisms from PAH-contaminated sediments which have the ability to metabolize and detoxify PAHs. 2. To determine the relationship between PAH structure and mineralization rates. 3. To determine whether differences in the physical, chemical and microbial characteristics of ecosystems predictably affect the disposition and persistence of PAHs in the environment. 4. To use multicomponent microcosms containing sediment and waste collected from chemically contaminated sites to determine the rate and extent of degradation of PAHs. Results of these studies in the biodegradation of PAHs will be presented.

Cerniglia, C.E. (National Center for Toxicological Research, Jefferson, AR (USA))

1989-01-01

227

Magnetic instability and pair binding in aromatic hydrocarbon superconductors.  

PubMed

Understanding magnetism and electron correlation in many unconventional superconductors is essential to explore mechanism of superconductivity. In this work, we perform a systematic numerical study of the magnetic and pair binding properties in recently discovered polycyclic aromatic hydrocarbon (PAH) superconductors including alkali-metal-doped picene, coronene, phenanthrene, and dibenzopentacene. The ?-electrons on the carbon atoms of a single molecule are modelled by the one-orbital Hubbard model, and the energy difference [Formula: see text] between carbon atoms with and without hydrogen bonds is taking into account. We demonstrate that the spin polarized ground state is realized for charged molecules in the physical parameter regions, which provides a reasonable explanation of local spins observed in PAHs. In alkali-metal-doped dibenzopentacene, our results show that electron correlation may produce an effective attraction between electrons for the charged molecule with one or three added electrons. PMID:23213358

Huang, Zhongbing; Zhang, Chao; Lin, Hai-Qing

2012-12-04

228

Transport of polycyclic aromatic hydrocarbons in highly vulnerable karst systems.  

PubMed

Fluxes of polycyclic aromatic hydrocarbons (PAHs) were investigated along the route of transport in a south German karst system. Atmospheric deposition, seepage water in caves and spring water at the outlet of the catchment were monitored continuously over 1.5 years allowing the establishment of an input/output mass balance at the catchment scale. The results reveal that, even in the highly vulnerable karst catchment, PAHs are effectively retained in the soils. Only during high discharge events, such as snowmelt in spring, increasing PAH concentrations at the outlet of the catchment indicates a mobilization of the pollutants. These events are typically correlated with increasing particle concentrations. Based on our results, we conclude that particle-facilitated transport is the dominating cause of PAH mobilization. In summary, PAHs accumulate over time in soils and only occasionally high discharge events cause a short concentration pulse to be flushed through the karst system. PMID:20974508

Schwarz, Kerstin; Gocht, Tilman; Grathwohl, Peter

2010-10-25

229

Sources, distribution, and toxicity of polycyclic aromatic hydrocarbons.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants released from the incomplete combustion of fossil fuels and are always found as a mixture of individual compounds. Due to economic growth and a sharp increase in energy consumption in recent years, large quantities of PAHs have been released into the environment worldwide. Because many PAHs and their derivatives are strongly potent carcinogens, or mutagens, PAHs have been extensively studied recently. The authors reviewed the origin and distribution of PAHs in atmosphere, soil, and sediment in natural environments. PAHs represent a class of toxicological compounds that can create a variety of hazardous effects in vivo/in vitro, including genotoxicity, immunotoxicity, developmental toxicity, and carcinogenesis, which the authors also describe. PMID:21644482

Guo, Yongyong; Wu, Kusheng; Huo, Xia; Xu, Xijin

2011-05-01

230

[Effect of polycyclic aromatic hydrocarbons on the immune system].  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds in our environment. They are formed during incomplete burning of coal, oil, gas, wood, garbage or other organic substances such as tobacco and charbroiled meat. PAHs enter the environment mostly as releases to air from volcanoes, forest fires, residential wood and coal burning and exhaust from automobiles and trucks. There are more than 100 different PAHs. Some of them have danger toxic properties including mutagenic and carcinogenic potential. Since 1993 PAHs are classified as the compounds which can cause immunosuppression. They reduce the body resistance against infection and cancer diseases. Immunosuppressive, carcinogenic and hypersensitivity effects of some PAHs representatives were described well in experimental studies. On the other hand, only sporadic information about immunological changes after long-term occupational exposure to PAHs were found from existing human epidemiological database. In addition, these studies usually did not cover the complex immunological profile represented by cellular and humoral activity. PMID:11253310

Bohácová, S; Borská, L; Fiala, Z; Andrýs, C

1999-01-01

231

Large Abundances of Polycyclic Aromatic Hydrocarbons in Titan's Upper Atmosphere  

NASA Astrophysics Data System (ADS)

In this paper, we analyze the strong unidentified emission near 3.28 ?m in Titan's upper daytime atmosphere recently discovered by Dinelli et al. We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 ?m. By using current models for the redistribution of the absorbed UV energy, we have explained the observed spectral feature and have derived the vertical distribution of PAH abundances in Titan's upper atmosphere. PAHs have been found to be present in large concentrations, about (2-3) × 104 particles cm-3. The identified PAHs have 9-96 carbons, with a concentration-weighted average of 34 carbons. The mean mass is ~430 u; the mean area is about 0.53 nm2 they are formed by 10-11 rings on average, and about one-third of them contain nitrogen atoms. Recently, benzene together with light aromatic species as well as small concentrations of heavy positive and negative ions have been detected in Titan's upper atmosphere. We suggest that the large concentrations of PAHs found here are the neutral counterpart of those positive and negative ions, which hence supports the theory that the origin of Titan main haze layer is located in the upper atmosphere.

López-Puertas, M.; Dinelli, B. M.; Adriani, A.; Funke, B.; García-Comas, M.; Moriconi, M. L.; D'Aversa, E.; Boersma, C.; Allamandola, L. J.

2013-06-01

232

Thermochemical Properties and Phase Behavior of Halogenated Polycyclic Aromatic Hydrocarbons  

PubMed Central

Knowledge of vapor pressure of organic pollutants is essential in predicting their fate and transport in the environment. In the present study, the vapor pressures of 12 halogenated polycyclic aromatic compounds (PACs), i.e. 9-chlorofluorene, 2,7-dichlorofluorene, 2-bromofluorene, 9-bromofluorene, 2,7-dibromofluorene, 2-bromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 9,10-dibromophenanthrene, 1-chloropyrene, 7-bromobenz[a]anthracene and 6,12-dibromochrysene, were measured using the Knudsen effusion method over the temperature range of 301 to 464 K. Enthalpies and entropies of sublimation of these compounds were determined via application of the Clausius–Clapeyron equation. The data were also compared with earlier published literature values to study the influence of halogen substitution on vapor pressure of PACs. As expected, the halogen substitution decreases vapor pressure compared to parent compounds, but does not necessarily increase the enthalpy of sublimation. Moreover, the decrease of vapor pressure also depends on the substitution position and the substituted halogen, and the di-substitution of chlorine and/or bromine decreases the vapor pressure compared to single halogen substituted polycyclic aromatic hydrocarbons. Additionally, the enthalpy of fusion and melting temperature of these 12 PACs were determined using differential scanning calorimetry and melting point analysis.

Suuberg, Eric M.

2013-01-01

233

Biodegradation of aromatic hydrocarbons by aquifer microorganisms under denitrifying conditions  

SciTech Connect

Laboratory tests were conducted to evaluate whether denitrification would be a suitable alternative for biorestoration of an aquifer contaminated with JP-4 jet fuel. Microcosms were prepared from uncontaminated and contaminated aquifer material, amended with nitrate, nutrients, and aromatic hydrocarbons, and incubated under a nitrogen atmosphere at 12 C. With uncontaminated core material, there was no observable lag period prior to removal of toluene whereas 30 days was required before biodegradation commenced for xylenes, ethylbenzene, and 1,2,4-trimethylbenzene. An identical test with contaminated aquifer material exhibited not only much longer lag periods but decreased rates of biodegradation; benzene, ethylbenzene, and o-xylene were not significantly degraded within the 6-month time period even though active denitrification occurred at this time. First-order biodegradation rate constants ranged from 0.016 to 0.38/day for uncontaminated core material and from 0.022 to 0.067/day for contaminated core material. Tests with individual compounds in uncontaminated core indicated that benzene and m-xylene inhibited the basal rate of denitrification. These data demonstrate that several aromatic compounds are degraded under denitrifying conditions, but rates of biodegradation may be lower in material contaminated with JP-4 jet fuel.

Hutchins, S.R.; Sewell, G.W.; Kovacs, D.A.; Smith, G.A.

1991-01-01

234

Biodegradation of aromatic hydrocarbons by aquifer microorganisms under denitrifying conditions  

SciTech Connect

A series of laboratory tests were conducted to evaluate whether denitrification would be a suitable alternative for biorestoration of an aquifer contaminated with JP-4 jet fuel. Microcosms were prepared from both uncontaminated and contaminated aquifer material from the site, in an anaerobic glovebox, amended with nitrate, nutrients, and aromatic hydrocarbons, and incubated under a nitrogen atmosphere at 12C. With uncontaminated core material, there was no observable lag period prior to removal of toluene whereas 30 days was required before biodegradation commenced for xylenes, ethylbenzene, and 1,2,4-trimethylbenzene. An identical test with contaminated aquifer material exhibited not only much longer lag periods but decreased rates of biodegradation; benzene, ethylbenzene, and o-xylene were not significantly degraded within the 6-month time period even though active denitrification occurred at this time. First-order biodegradation rate constants ranged from 0.016 to 0.38 day{sup {minus}1} for uncontaminated core material and from 0.022 to 0.067 day{sup {minus}1} for contaminated core material. Tests with individual compounds in uncontaminated core indicated that benzene and m-xylene inhibited the basal rate of denitrification. These data demonstrate that several aromatic compounds can be degraded under denitrifying conditions, but rates of biodegradation may be lower in material contaminated with JP-4 jet fuel.

Hutchins, S.R.; Sewell, G.W.; Smith, G.A. (Environmental Protection Agency, Ada, OK (USA)); Kovacs, D.A. (NSI Technology Services, Ada, OK (USA))

1991-01-01

235

Heterogeneous catalyzed benzylic acetoxylation of methylated aromatic hydrocarbons  

SciTech Connect

The palladium-catalyzed acetoxylation of toluene to benzyl acetate is highly dependent on particle size. The rate of reaction is highest with 30--35 [Angstrom] particles corresponding to a 0.33 dispersion. Catalysts prepared and reduced by controlled methods before being contacted with the reaction medium, ex situ catalysts, were found to yield lower reaction rates than catalysts prepared in the reaction medium, in situ. Potassium ion-encapsulation in palladium during in situ preparation is a possible explanation for this result. Tin is required to reduce Pd[sup 2+] to Pd[sup 0] in the in situ system, but is not required for the ex situ catalyst. The improvement in activity of the ex situ catalyst in the presence of tin may be due to the reducibility of Sn[sup 4+] to Sn[sup 2+] during oxygen-poor regimes. Results obtained with diverse methylated aromatic hydrocarbons indicate that the aromatic ring interactions with the palladium surface via [pi]-donation before oxidation occurs. 37 refs., 7 figs., 5 tabs.

Benazzi, E.; Mimoun, H.; Cameron, C.J. (Institut Francais du Petrole, Rueil-Malmaison (France))

1993-04-01

236

Large Molecules, Ions, Radicals, and Small Soot Particles in Fuel-Rich Hydrocarbon Flames Part VI: Positive Ions of Aliphatic and Aromatic Hydrocarbons in a Low-Pressure Premixed Flame of n-Butane and Oxygen1  

Microsoft Academic Search

Previous studies of large hydrocarbons in fuel-rich hydrocarbon flames have shown that the hydrogen content of intermediate large polycyclic aromatic hydrocarbons (PAH), which is correlated with their molecular structure, plays an important role in their growth pathways. For this reason it was investigated whether n-butane as fuel which is rich in hydrogen would have influence on the formation of H-rich

A. B. FIALKOV; K.-H. HOMANN

237

Aromaticity of giant polycyclic aromatic hydrocarbons with hollow sites: super ring currents in super-rings.  

PubMed

We present a systematic theoretical study based on semi-empirical, Hartree-Fock (HF), and density functional theory (DFT) models of a series of polycyclic aromatic hydrocarbons (PAHs) that exhibit hollow sites. In this study we focus particularly on the magnetic criteria of aromaticity, namely (1)H NMR and nucleus-independent chemical shifts (NICS), and on their relationships with other electronic properties. The computed shifts and NICS indices indicate that an external magnetic field induces exceptionally strong ring currents in even-layered PAH doughnuts, in particular in the layer directly adjacent to the central hole of double-layered compounds. These exceptionally strong ring currents also correlate with particularly small HOMO-LUMO gaps and electronic excitation energies and to abnormally high polarizabilities, indicating in turn that these compounds have a more pronounced metallic character. Comparison is made with further depictions of aromaticity in these systems and in [18]-[66]annulene rings by employing topological, structural, and energetic criteria. PMID:16718724

Hajgató, Balázs; Deleuze, Michael S; Ohno, Koichi

2006-07-24

238

Development of a groundwater biobarrier for the removal of polycyclic aromatic hydrocarbons, BTEX, and heterocyclic hydrocarbons.  

PubMed

A full scale funnel-and-gate biobarrier has been developed for the removal of tar oil pollutants at an abandoned tar factory site near the city of Offenbach, Germany. Laboratory and on-site column studies were done to determine the operation parameters for microbiological clean-up of the groundwater polluted with 12,000 microg/L mono- aromatic hydrocarbons such as benzene and the xylenes, 4,800 microg/L polycyclic aromatic hydrocarbons such as naphthalene and acenaphthene, and 4,700 microg/L heterocyclic aromatic hydrocarbons such as benzofuran and benzothiophene. In the laboratory study, a residence time of approx. 70 h proved to be sufficient for aerobic pollutant biodegradation. Up to 180 mg/L H(2)O(2) were added and did not lead to any toxic effects to the degrading bacteria. The feasibility of the concept was confirmed in an on-site pilot study performed with a sedimentation tank (removal of ferric iron) and two bioreactors. In the bioreactors, >99.3% of the pollutants were degraded. Biodegradation activity corresponded to a significant increase in numbers of pollutant degrading bacteria. In the bioreactors, a fast dissociation of H(2)O(2) was observed resulting in losses of oxygen and temporary gas clogging. Therefore, a repeated addition of moderate concentrations of H(2)O(2) proved to be more favourable than the addition of high concentrations at a single dosing port. The full scale biobarrier consists of three separated bioreactors thus enabling extended control and access to the reactors. The operation of the funnel-and-gate biobarrier started in April 2007, and represents the first biological permeable reactive barrier with extended control (EC-PRB) in Germany. PMID:18957746

Tiehm, A; Müller, A; Alt, S; Jacob, H; Schad, H; Weingran, C

2008-01-01

239

Novel C-ring cleaved triterpenoid-derived aromatic hydrocarbons in Tertiary brown coals  

NASA Astrophysics Data System (ADS)

Five novel ethylene-linked polymethyl-substituted phenyl/naphthyl or naphthyl/naphthyl hydrocarbons have been identified in aromatic hydrocarbon fractions of immature Tertiary coals using liquid chromatography, gas chromatography (GC), and GC coupled to mass spectrometry. These compounds are produced during coalification through triterpenoid aromatization processes that involve C-ring opening (C 8(14) bond cleavage) and preservation or loss of the A-ring. This second type of reaction is illustrated here for the first time. Structures corresponding to various degrees of aromatization have been found, indicating that these hydrocarbons undergo further aromatization after C-ring cleavage. All these compounds are observed to occur only in coals corresponding to diagenetic conditions that have also resulted in the formation of C-ring preserved triterpenoid-derived hydrocarbons containing more than two aromatic rings.

de las Heras, F. X.; Grimalt, J. O.; Albaigés, J.

1991-11-01

240

Reduction of Aromatic Hydrocarbons by Zero-Valent Iron and Palladium Catalyst  

SciTech Connect

Permeable reactive barrier (PRB) is an alternative technology for soil and groundwater remediation. Zero valent iron, which is the most popular PRB material, is only applicable to halogenated aliphatic organics and some heavy metals. The objective of this study was to investigate reductive dechlorination of halogenated compounds and reduction of non-halogenated aromatic hydrocarbons using zero valent metals (ZVMs) and catalysts as reactive materials for PRBs. A group of small aromatic hydrocarbons such as monochlorophenols, phenol and benzene were readily reduced with palladium catalyst and zero valent iron. Poly-aromatic hydrocarbons (PAHs) were also tested with the catalysts and zero valent metal combinations. The aromatic rings were reduced and partly reduced PAHs were found as the daughter compounds. The current study demonstrates reduction of aromatic compounds by ZVMs and modified catalysts and implicates that PRB is applicable not only for halogenated organic compounds but nonhalogenated aromatic compounds such as PAHs.

Kim, Young-Hun; Shin, Won Sik; Ko, Seok-Oh; Kim, Myung-Chul

2004-03-31

241

Polycyclic Aromatic Hydrocarbons in an industrialized urban area  

NASA Astrophysics Data System (ADS)

Urbanization, agricultural intensification and industrialization are contributing to erosion, local and diffuse contamination and sealing of soil surfaces, resulting in soil quality degradation. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in urban environments and considered good markers of anthropogenic activities such as traffic, industry, domestic heating and agriculture. Although they are subject to biodegradation and photodegradation, once in the soil, they tend to bind to the soil organic fraction. Estarreja is a small coastal town in the Northwestern Portuguese coast, with a close relation with the lagoon of Aveiro which supports a variety of biotopes (channels, islands with vegetation, mudflats, salt marshes and agricultural fields) of important ecological value. It supports an intensive and diversified agriculture, a variety of heavy and light industries and a population of about half a million people which is dependent on this resource. This is a very industrialized area, due to its five decades of chemical industry. This study aims to assess the impact of the urbanization and of the chemical industry in PAHs distribution. The survey and sampling method were based on pre-interpreted maps, aerial photographs, and directly checked in the field, in order to get an overall characterization of the area. Topsoils were collected from 34 sites, considering different land uses. Five land uses were chosen: ornamental gardens, parks, roadsides, forest and agricultural. Parameters such as soil pH (ISO method 10390:1994), total C, N, H, S percentages (microanalyser LECO, CNHS-932), organic matter (LOI at 430°), particle size distribution (Micromeritics® Sedigraph 5100), cation exchange capacity and exchangeable bases, were determined in order to have a general characterization of soil. Determination of the 16 EPA PAHs in soils was performed by GC/MS after a Soxhlet extraction and an alumina clean-up of extracts. Procedure blanks, duplicates and reference material were used in each extraction batch for quality control assessment. In what concerns the general parameters, Estarreja soils were characterized as slightly acid, with a median pHCaCl2 of 5.15, ranging from 3.12 and 6.88. The content in organic matter observed was relatively high, with a median of 4.6% and ranging from 1.8 to 45%. The median concentration of PAHs was 98 µg kg-1, ranging from 27 to 2,016 µg kg-1. The former value was found in an agricultural area and, together with another agricultural soil (with 1121 µgPAHs/kg), were considered heavily contaminated according to the classification given by Maliszewska-Kordybach. Moreover, eight samples were classified as weakly contaminated (PAHs between 200 and 600 µg/kg) and the remaining ones were not contaminated. The relative abundance of individual PAHs in Estarreja soils was evaluated, being the most abundant Fluoranthene and Pyrene followed by Benzo(b)fluoranthene, Phenanthrene and Crysene. These PAHs are the ones usually associated with the combustion of fossil fuel and other burnable materials, being this composition is typical for topsoil of European industrialized countries. Geostatistical methods were used to show the spatial variability of contaminants and the probability of exceeding the risk-based standards. The plots of concentration of PAHs on GIS highlight areas where the highest elements concentrations occur and the land use associated. These soil maps assemble important information for decision-making, allowing identifying possible sources of contamination, assess the suitability of soil to its use and to contribute for land use planning in accordance to soil characteristics. Acknowledgements: This work was supported by the Portuguese Foundation for Science and Technology (SFRH/BD/38418/2007) and by CESAM

Cachada, A.; Pereira, R.; Ferreira da Silva, E.; Duarte, A. C.

2009-04-01

242

Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments from the Eastern Aegean: assessment and source recognition of petroleum hydrocarbons  

Microsoft Academic Search

Materials and methods  Aliphatic and polycyclic aromatic hydrocarbons (PAHs) were determined in surficial sediments from the Aegean Sea in the Eastern\\u000a Mediterranean in 2008.\\u000a \\u000a \\u000a \\u000a \\u000a Results  Total aliphatic hydrocarbons (n-C12 to n-C35) ranged from 330 to 2,660 ng g-1 dry weight (dwt), while aromatics (19 PAHs) varied between 73.5 and 2,170 ng g-1 dwt. Total concentrations of both aliphatic hydrocarbons and PAHs ranged

L. Tolga Gonul; Filiz Kucuksezgin

243

Determination of aromatic hydrocarbons and their metabolites in human blood and urine.  

PubMed

Methods for the biological monitoring of aromatic hydrocarbons and their metabolites in the human blood and urine are reviewed. For the determination of the unchanged aromatic hydrocarbon in blood, gas chromatographic head-space analysis is recommended. The metabolites can be monitored by photometric, thin-layer chromatographic, high-performance liquid chromatographic and gas chromatographic methods. For the assessment of health risks caused by aromatic hydrocarbons, reference values and occupational limit values, expressed as biological tolerance values and biological exposure indices, have to be considered. PMID:1400824

Angerer, J; Hörsch, B

1992-09-16

244

Characterisation of polycyclic aromatic hydrocarbons in liquid products from pyrolysis of Eucalyptus grandis by supercritical fluid extraction and GC\\/MS determination  

Microsoft Academic Search

Slow pyrolysis of Eucalyptus grandis wood was performed in an oven laboratory and liquid products were quantitatively collected. Polycyclic aromatic hydrocarbons (PAHs) content was obtained by partitioning the pyrolysis liquid products with supercritical CO2 extraction followed by GC\\/MS analysis. The SFE procedures were validated by comparing the PAH content with those obtained by means of adsorption column chromatography. While extracted

A. S. Pimenta; B. R. Vital; J. M. Bayona; R. Alzaga

1998-01-01

245

The Photochemistry of Polycyclic Aromatic Hydrocarbons (PAHs) in Water Ice  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) and related aromatic materials are present in virtually all phases of the interstellar medium. In dense clouds, they condense out of the gas and become part of the water-rich mixed molecular ices that are a major component of the dust in dense molecular clouds. PAHs are also likely to be frozen on icy Solar System objects. Although the UV radiative processing of simple mixed molecular ices has been studied for nearly 30 years, research into the in-situ photochemistry of PAH containing ices has only recently begun. This paper will review some of that work. The vacuum ultraviolet (VUV) photochemistry of the PAHs naphthalene, pyrene, 4-methylpyrene and quatterylene in water ice at 10 to 30 K will be summarized. In all cases, the neutral parent PAH is readily and efficiently (>70%) converted to the radical cation (PAH+) form upon exposure to VUV radiation. These PAH cations remain trapped and stabilized within the ice to remarkably high temperatures as the ice is warmed to the sublimation point. To understand the chemical processes and kinetics during photolysis we carried out a systematic study on several PAH/H2O ices. A new apparatus was developed which permits tracking the in-situ behavior of the parent PAH and its photoproducts as a function of ice temperature and time with sub-second responsivity. Ice temperature determines the dominant reaction routes while photolysis duration processes the ice. The ability to measure spectra simultaneously with photolysis and with sub-second time resolution permits kinetic studies previously inaccessible and provides new insights into the processes occurring within the ice during photolysis. These studies show that PAHs may well play important but overlooked roles in cosmic ice chemistry and physics, whether they are in the Solar System or near star forming regions in dense clouds.

Allamandola, L. J.; Bouwman, J.; Cuppen, H.; Gudipati, M. S.; Linnartz, H.

2009-12-01

246

Emission of polycyclic aromatic hydrocarbons from gasohol and ethanol vehicles  

NASA Astrophysics Data System (ADS)

The exhaust emission of the polycyclic aromatic hydrocarbons (PAHs) considered toxic to human health were investigated on two spark ignition light duty vehicles, one being gasohol (Gasohol, in Brazil, is the generic denomination for mixtures of pure gasoline plus 20-25% of anhydrous ethyl alcohol fuel (AEAF).)-fuelled and the other a flexible-fuel vehicle fuelled with hydrated ethanol. The influence of fuel type and quality, aged lubricant oil type and use of fuel additives on the formation of these compounds was tested using standardized tests identical to US FTP-75 cycle. PAH sampling and chemical analysis followed the basic recommendations of method TO-13 (United States. Environmental Protection Agency, 1999. Compendium Method TO-13A - Determination of polycyclic Aromatic hydrocarbons (PAH) in Ambient Air Using Gas Chromatography/Mass Spectrometry (CG/MS). Center for environmental research information, Cincinnati, p. 78), with the necessary modification for this particular application. Results showed that the total PAH emission factor varied from 41.9 ?g km -1 to 612 ?g km -1 in the gasohol vehicle, and from 11.7 ?g km -1 to 27.4 ?g km -1 in the ethanol-fuelled vehicle, a significant difference in favor of the ethanol vehicle. Generally, emission of light molecular weight PAHs was predominant, while high molecular weights PAHs were not detected. In terms of benzo( a)pyrene toxicity equivalence, emission factors varied from 0.00984 ?g TEQ km -1 to 4.61 ?g TEQ km -1 for the gasohol vehicle and from 0.0117 ?g TEQ km -1 to 0.0218 ?g TEQ km -1 in the ethanol vehicle. For the gasohol vehicle, results showed that the use of fuel additive causes a significant increase in the emission of naphthalene and phenanthrene at a confidence level of 90% or higher; the use of rubber solvent on gasohol showed a reduction in the emission of naphthalene and phenanthrene at the same confidence level; the use of synthetic oil instead of mineral oil also contributed significantly to a decrease in the emission of naphthalene and fluorene. In relation to the ethanol vehicle, the same factors were tested and showed no statistically significant influence on PAH emission.

de Abrantes, Rui; Vicente de Assunção, João; Pesquero, Célia Regina; Bruns, Roy Edward; Nóbrega, Raimundo Paiva

247

Capillary chromatography of polycyclic aromatic hydrocarbons on glass and quartz capillary columns coated with stationary polysiloxane phases  

SciTech Connect

This paper resports a technique for analyzing automobile exhausts for polycyclic aromatic hydrocarbons (PAH's) by means of a new Biokhrom-1 chromatograph designed to operate with capillary glass and quartz columns. The method is assessed for performance and is shown to be useful in monitoring the PAH content in the environment. The detection limit for benz(a)pyrene was 0.05 ug with a relative standard deviation of 0.08 to 0.12.

Rudenko, B.A.; Bulycheva, Z.Y.; Kutenev, V.F.; Topunov, V.N.

1985-09-01

248

Changes of solid phase toxicity during sewage sludge composting in relation to bioavailability of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

The aim of the present study was to determine the content of the bioaccessible fraction of polycyclic aromatic hydrocarbons (PAHs) in sewage sludges and composts by means of three techniques (solid phase extraction with Tenax-TA and non-exhaustive extraction with hydroxypropyl[?]cyclodextrin and n-butanol) and at the same time to establish their influence on toxicity for Heterocypris incongruens (Ostracodtoxkit test) and Lepidium

Patryk Oleszczuk

2009-01-01

249

QSARS FOR PREDICTING REDUCTIVE TRANSFORMATION RATE CONSTANTS OF HALOGENATED AROMATIC HYDROCARBONS IN ANOXIC SEDIMENT SYSTEMS  

EPA Science Inventory

Quantitative structure-activity relationships (QSARs) are developed relating initial and final pseudo-first-order disappearance rate constants of 45 halogenated aromatic hydrocarbons in anoxic sediments to four readily available molecular descriptors: the carbon-halogen bond stre...

250

PHOTOACTIVATION AND TOXICITY OF MIXTURES OF POLYCYCLIC AROMATIC HYDROCARBON COMPOUNDS IN MARINE SEDIMENT  

EPA Science Inventory

The direct toxicity and photoinduced toxicity of sediment-associated acenaphthene, phenanthrene, fluoranthene, and pyrene were determined for the marine amphipod Rhepoxynius abronius. The four polycyclic aromatic hydrocarbons (PAHs) were spiked into sediment in a concentration se...

251

Prediction of Retention Indices of Polynuclear Aromatic Hydrocarbons. Part II. Capillary Gas Chromatography.  

National Technical Information Service (NTIS)

A trigonal additivity procedure has been examined and found to correlate well with retention indices for polynuclear aromatic hydrocarbons on several gas chromatographic stationary phases. The results of this analysis are compared to those obtained using ...

C. N. Ho J. R. Kennedy G. R. Samyajulu D. Karlesky I. M. Warner

1984-01-01

252

Adsorption Studies Evaluating Codisposal of Coal Gasification Ash with Wastewater Sludges Containing Polycyclic Aromatic Hydrocarbons.  

National Technical Information Service (NTIS)

The extent to which polycyclic aromatic hydrocarbons (PAHs) are sorbed onto gasifier ash was investigated in batch and column sorption studies. The batch studies involved characterizing the adsorption and desorption of phenanthrene, anthracene, benzo(a)py...

J. W. Kilmer R. A. Minear C. W. Francis

1987-01-01

253

Reactivity of Polynuclear Aromatic Hydrocarbons with O2 and NO in the Presence of Light.  

National Technical Information Service (NTIS)

The reactivity of 20 different aromatic hydrocarbons adsorbed on solid polystyrene fluffs with oxygen and nitric oxide in the presence of light has been studied. The reaction conditions simulated those encountered in polluted atmospheres. Among the compou...

N. E. Geacintov

1973-01-01

254

STUDIES ON BIOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBON-CONTAMINATED SEDIMENTS: BIOAVAILABILITY, BIODEGRADABILITY, AND TOXICITY ISSUES  

EPA Science Inventory

The widespread contamination of aquatic sediments by polycyclic aromatic hydrocarbons (PAHs) has created a need for cost-effective bioremediation processes, on which the bioavailability and the toxicity of PAHs often have a significant impact. This research investigated the biode...

255

Molecular catalytic hydrogenation of aromatic hydrocarbons and hydrotreating of coal liquids.  

SciTech Connect

This report presents the results of research on the development of new catalytic pathways for the hydrogenation of multiring aromatic hydrocarbons and the hydrotreating of coal liquids at The University of Chicago under DOE Contract No. DE-AC22-91PC91056. The work, which is described in three parts, is primarily concerned with the research on the development of new catalytic systems for the hydrogenation of aromatic hydrocarbons and for the improvement of the quality of coal liquids by the addition of dihydrogen. Part A discusses the activation of dihydrogen by very basic molecular reagents to form adducts that can facilitate the reduction of multiring aromatic hydrocarbons. Part B examines the hydrotreating of coal liquids catalyzed by the same base-activated dihydrogen complexes. Part C concerns studies of molecular organometallic catalysts for the hydrogenation of monocyclic aromatic hydrocarbons under mild conditions.

Yang, Shiyong; Stock, L.M.

1996-05-01

256

AMENDMENT OF SEDIMENTS WITH A CARBONACEOUS RESIN REDUCES BIOAVAILABILITY OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

A series of laboratory and field test studies were conducted to evaluate the effectiveness of Ambersorb, a carbonaceous resin, in reducing bioavailability of polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments collected from the field. Amending contaminated sediment...

257

Atmospheric Fallout of Polycyclic Aromatic Hydrocarbons in a Marine Coastal Area.  

National Technical Information Service (NTIS)

16 polycyclic aromatic hydrocarbons (PAH) have been sampled at two stations on the coast of a Danish inlet and analysed by HPLC. The yearly deposition has been estimated and the possible sources are being discussed. (ERA citation 11:014458)

K. Jensen

1983-01-01

258

Public Health Impacts of Secondary Particulate Formation from Aromatic Hydrocarbons in Gasoline  

EPA Science Inventory

Background: Aromatic hydrocarbons emitted from gasoline�powered vehicles contribute to the formation of secondary organic aerosol (SOA), which increases the atmospheric mass concentration of fine particles (PM2.5). Here we estimate the public health burden associated w...

259

Modeling the Role of Alkanes, Polycyclic Aromatic Hydrocarbons, and Their Oligomers in Secondary Organic Aerosol Formation  

EPA Science Inventory

A computationally efficient method to treat secondary organic aerosol (SOA) from various length and structure alkanes as well as SOA from polycyclic aromatic hydrocarbons (PAHs) is implemented in the Community Multiscale Air Quality (CMAQ) model to predict aerosol concentrations ...

260

COMPUTATIONAL METHODS FOR STUDYING THE INTERACTION BETWEEN POLYCYCLIC AROMATIC HYDROCARBONS AND BIOLOGICAL MACROMOLECULES  

EPA Science Inventory

Computational Methods for Studying the Interaction between Polycyclic Aromatic Hydrocarbons and Biological Macromolecules . The mechanisms for the processes that result in significant biological activity of PAHs depend on the interaction of these molecules or their metabol...

261

CHEMICAL ACTIVATION OF NON-MUTAGENIC NITRATED POLYCYCLIC AROMATIC HYDROCARBONS TO MUTAGENS  

EPA Science Inventory

Nitrated polycyclic aromatic hydrocarbons, including carcinogens, may be non-mutagenic in microorganisms because bacterial nitroreductases are unable to reduce their nitro function to proximate mutagenic hydroxylamines. The reduction of the nitro moiety can be accomplished chemic...

262

COMPUTER AUTOMATED EVALUATION OF MUTAGENICITY AND CARCINOGENICITY OF SELECTED POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

The mechanisms by which polycyclic aromatic hydrocarbons (PAHs) induce mutations and cancer have been the subject of considerable attention for several years. arious theoretical and experimental models have been advanced the effects of structural variations on mutagenicity and ca...

263

Comparison of Drinking Water Mutagenicity with Leaching of Polycyclic Aromatic Hydrocarbons from Water Distribution Pipes.  

National Technical Information Service (NTIS)

The primary objectives of the study were to examine the changes in concentration of six polycyclic aromatic hydrocarbons (PAH) and the possibility of changes in mutagenic potential of treated waters as a result of their passage through commonly used distr...

D. K. Basu J. Saxena F. W. Stoss J. Santodonato M. W. Neal

1987-01-01

264

ANALYSIS OF POLYNUCLEAR AROMATIC HYDROCARBONS IN PARTICULATE MATTER BY LUMINESCENCE TECHNIQUES  

EPA Science Inventory

Fluorescence, phosphorescence, and heavy-metal activated room temperature phosphorescence spectra were obtained for ten polycyclic aromatic hydrocarbon (PAH) reference compounds individually and in mixtures on quartz plates and particulate matter. The results indicate that multic...

265

Investigation of Polycyclic Aromatic Hydrocarbon Discharges to Water in the Vicinity of Buffalo, New York.  

National Technical Information Service (NTIS)

Eastern Lake Erie and the upper Niagara River basin were sampled for polycyclic aromatic hydrocarbons (PAH) to assess their distribution and sources. Twenty-five sites were sampled using polypropylene substrates. Five areas were identified as having relat...

E. J. Kuzia J. J. Black

1985-01-01

266

Presenza degli Idrocarburi Policiclici Aromatici Negli Alimenti. (Occurrence of Polycyclic Aromatic Hydrocarbons in Food).  

National Technical Information Service (NTIS)

Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous organic compounds, whose occurrence in food may be due to environmental contamination, processing or domestic cooking methods. PAHs are of health concern due to the carcinogenicity shown by many of th...

B. Bocca R. Crebelli E. Menichini

2003-01-01

267

EPA (Envionmental Protection Agency) Method Study 20, Method 610--PNA's (Polynuclear Aromatic Hydrocarbons).  

National Technical Information Service (NTIS)

Sixteen laboratories participated in an interlaboratory study conducted to provide precision and accuracy statements for the proposed EPA Method 610 for 16 selected polynuclear aromatic hydrocarbons(PNA's) which may be present in municipal and industrial ...

G. Kinzer R. Riggin T. Bishop M. A. Birts P. Strup

1984-01-01

268

Product Studies of the Atmospherically-Important Reactions of Alkenes and Aromatic Hydrocarbons.  

National Technical Information Service (NTIS)

Alkenes and aromatic hydrocarbons are important constituents of ambient air in polluted urban areas, and their atmospheric reactions in the presence of oxides of nitrogen lead to the formation of ozone and other manifestations of photochemical air polluti...

R. Atkinson J. Arey E. C. Tuazon

1997-01-01

269

Unusual Hydrocarbon Emission From the Early Carbon Star HD 100764: The Connection Between Aromatics and Aliphatics.  

National Technical Information Service (NTIS)

We have used the Infrared Spectrograph (IRS) on the Spitzer Space Telescope to obtain spectra of HD 100764, an apparently single carbon star with a circumstellar disk. The spectrum shows emission features from polycyclic aromatic hydrocarbons (PAHs) that ...

G. C. Sloan J. Bernard- Salas K. E. Kraemer M. Jura W. W. Duley

2007-01-01

270

Biostabilization of Polycyclic Aromatic Hydrocarbons (PAHs) Under Denitrification Conditions in Sediments.  

National Technical Information Service (NTIS)

Carnegie Mellon University and Stanford University investigated the anaerobic biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments under bioslurry denitrifying conditions. Samples from sediment bioslurry tests and toxicity b...

J. T. Bushey I. Ahn U. Ghosh R. G. Luthy T. Mahajan

2000-01-01

271

Combined Chemical and Biological Oxidation of Slurry Phase Polycyclic Aromatic Hydrocarbons.  

National Technical Information Service (NTIS)

Bioslurry treatment of polycyclic aromatic hydrocarbon (PAH)-impacted soils was demonstrated under the Superfund Innovative Technologies Evaluation (SITE)/Emerging Technologies Program (ETD) as an extension of research previously funded by IT Corporation ...

K. L. Brown B. Davila J. Sanseverino M. Thomas C. Lang J. Rightmyer K. Hague T. Smith

1995-01-01

272

Maternal Transfer of Bioactive Polychlorinated Aromatic Hydrocarbons in Spawning Chinook Salmon ('Obchrhynchus tschawytscha').  

National Technical Information Service (NTIS)

The biological potency (relative to 2,3,7,8,-tetrachlorodibenzo-p-dioxin, TCDD) of planar polychlorinated aromatic hydrocarbons (PCHs) in extracts of eggs and flesh from spawning female chinook salmon (Oncorhynchus tschawytscha) from Lake Michigan was det...

G. T. Ankley D. E. Tillitt J. P. Giesy

1989-01-01

273

Occurrence of polycyclic aromatic hydrocarbons in dust emitted from circulating fluidized bed boilers.  

PubMed

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in granulometric fractions of dust emitted from a hard coal fired circulating fluidized bed (CFB) boiler was investigated. The dust was sampled with the use of a Mark III impactor. In each fraction of dust, by using gas chromatography (GC), 16 selected PAHs and total PAHs were determined and the toxic equivalent B(a)P (TE B(a)P) was computed. The results, recalculated for the standard granulometric fractions, are presented as concentrations and content of the determined PAHs in dust. Distributions of PAHs and their profiles in the granulometric dust fractions were studied also. The PAHs in dust emitted from the CFB boiler were compared with those emitted from mechanical grate boilers; a distinctly lower content of PAHs was found in dust emitted from the former. PMID:18975852

Kozielska, B; Konieczy?iski, J

2008-11-01

274

Polycyclic aromatic hydrocarbons in Australian coals. III. Structural elucidation by proton nuclear magnetic resonance spectroscopy  

SciTech Connect

The molecular structures of a number of tetra- and pentacyclic aromatic hydrocarbons present in extracts of Victorian brown coal have been unambiguously established by /sup 1/H-NMR. The determined structures support the hypothesis that these polycyclic aromatic hydrocarbons (PAHs) are diagenetically derived from triterpenoid precursors based on the oleanane, ursane and lupane skeletons. The occurrence of diastereoisomerism in these PAHs has been revealed for the first time and the diastereomeric configurations of one pair of triaromatic compounds (XI and XII) defined.

Chaffee, A.L.; Fookes, C.J.R.

1988-01-01

275

Evaluation of Toxic Activities of Polycyclic Aromatic Hydrocarbon Derivatives Using In Vitro Bioassays  

Microsoft Academic Search

Several polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons (PAHs\\/NPAHs) such as benzo(a)pyrene and 1-nitropyrene are mutagens and\\/or carcinogens. These compounds secondarily generate PAH hydroxides, ketones, and quinones through atmospheri ca nd metabolic reactions. The health effects of these compounds is now an important social concern. For example, lung cancer, bronchitis, whistling and so on. In this work, we evaluated

Kanae Bekki; Hidetaka Takigami; Go Suzuki; Ning Tang; Kazuichi Hayakawa

2009-01-01

276

Electrochemiluminescence Determination of Nitro Polycyclic-Aromatic Hydrocarbons Using HPLC Separation  

Microsoft Academic Search

Summary In order to analyse nitro-polycyclic aromatic hydrocarbons (NPAHs), the NPAHs were reduced to amino-polycyclic aromatic hydrocarbons (APAHs), separated by HPLC and monitored with electrochemiluminescence detection (ECL). Based on a post-column reaction with bis(2,4,6-trichlorophenyl) oxalate, the ECL observations of APAHs were performed in hydrogen peroxide solution, which was electrogenerated from an electrolysis flow cell equipped with a reticulated vitreous carbon

X. Chen; M. J. Li; C. Q. Yi; Y. Tao; X. R. Wang

2003-01-01

277

Deposition of platinum group elements and polycyclic aromatic hydrocarbons on ryegrass exposed to vehicular traffic  

Microsoft Academic Search

Along highways, platinum group elements (PGE: Pt, Pd and Rh) and polycyclic aromatic hydrocarbons (PAHs) produced by the vehicle\\u000a traffic can be deposited on grass and soil, leading to a risk of contamination through the food chain via farm animals. We\\u000a studied the deposition of platinum group elements and polycyclic aromatic hydrocarbons on ryegrass pots exposed along a highway\\u000a with

Abdourahamane Tankari Dan-Badjo; Cécile Ducoulombier-Crépineau; Claire Soligot; Cyril Feidt; Guido Rychen

2007-01-01

278

Biodegradation of aged polycyclic aromatic hydrocarbons (PAHs) by microbial consortia in soil and slurry phases  

Microsoft Academic Search

Microbial consortia isolated from aged oil-contaminated soil were used to degrade 16 polycyclic aromatic hydrocarbons (15.72mgkg?1) in soil and slurry phases. The three microbial consortia (bacteria, fungi and bacteria–fungi complex) could degrade polycyclic aromatic hydrocarbons (PAHs), and the highest PAH removals were found in soil and slurry inoculated with fungi (50.1% and 55.4%, respectively). PAHs biodegradation in slurry was lower

Xiaojun Li; Peijun Li; Xin Lin; Chungui Zhang; Qi Li; Zongqiang Gong

2008-01-01

279

Sequential accelerated solvent extraction of polycyclic aromatic hydrocarbons with different solvents: performance and implication.  

PubMed

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) extracted by Soxhlet extraction (S-PAHs) with dichloromethane and routine accelerated solvent extraction (A-PAHs) with 1:1 toluene/methanol, respectively, were investigated in 24 soil samples from two cities in the center of the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons, methylphenanthrene and perylene, in two soils, two sediments, and an immature oil shale were also sequentially extracted by accelerated solvent extraction (ASE) with each of four different organic solvents for three times. The A-PAHs' concentrations are 2.41 times the S-PAHs' concentrations. For sequential three ASEs, PAHs in the first extract account for 56 to 67% of their total concentrations in the sequential three extractions and toluene displays the best extraction performance among the four solvents. Diagnostic ratios of PAHs in Soxhlet extraction, routine ASE, and sequential ASE with each solvent for a given sample are very similar, suggesting their identical petrogenic and pyrogenic sources in the soils and sediments. But the PAH ratios for the shale have an obvious petrogenic origin. The perylene/5-ring PAH ratios indicate a diagenetic source, especially in the shale and sediments. The correlation analysis shows that A-PAHs/S-PAHs is better associated with the contents of total organic carbon (TOC) than those of black carbon (BC). The above results indicate the significant petrogenic origin of PAHs and the important effect of organic matter on their extraction and distribution in the investigated field soils/sediments. PMID:21284305

Ma, Xiaoxuan; Ran, Yong; Gong, Jian; Chen, Diyun

280

Environmental exposure to polycyclic aromatic hydrocarbons in Czech Republic.  

PubMed

1 Objectives of this study were (1) to compare concentrations of individual polycyclic aromatic hydrocarbons (PAH) in air of polluted and nonpolluted area of Czech Republic during winter and summer periods and (2) to verify if urinary 1-hydroxypyrene (1-OHP), as supposed practical biological marker, permits the assessment of spacial and temporal variations in environmental PAH exposure. 2 The study population consisted of three groups: (1) a group of 22 physical exercise students who regularly train outside, from the university situated in a polluted town, spending 14 days in winter and 14 days in summer in 'non-polluted' mountains; (2) a control group of 22 residents from the town and (3) a control group of 18 residents from the mountains. 3 The total PAH concentrations (sum of 13 individual PAH) were 19.3 and 104.6 ng/m3 in town and in mountains, respectively, during summer and 86.6 and 261 ng/m3 during winter. 4 Median 1-OHP levels ranged between 0.03 and 0.13 mumol/mol creatinine for controls and between 0.04 and 0.12 mumol/mol creatinine for students. No relationship was found between pyrene levels in air and group means of urinary 1-OHP. Our results show that other factors (probably PAH in food) contribute in masking air pollution influence on urinary 1-OHP levels in subjects non-occupationally exposed to PAH. PMID:9363476

Vyskocil, A; Fiala, Z; Fialova, D; Krajak, V; Viau, C

1997-10-01

281

Contorted polycyclic aromatic hydrocarbons: Synthesis, structure, and function  

NASA Astrophysics Data System (ADS)

The following thesis focuses on novel polycyclic aromatic hydrocarbons (PAHs) as materials for electronic applications. Many of the molecules described herein fall under the subheading of contorted PAHs indicating their distortion from the planar structure that is typical of PAHs. Chapter two describes a series of contorted PAHs that were synthesized enroute to a molecular bowl. These molecules represent some of the most contorted PAHs. Their structures are intriguing and may inspire materials that can discriminate between various curvatures. The third chapter tells the story of organic photovoltaics (OPVs) based on contorted-hexabenzocoronene (HBC). The curvature of HBC lends itself to a complementary relationship with C60. This relationship was exploited for investigating organic-organic interfaces in OPVs. Chapter four contains the syntheses and unusual properties of extended contorted PAHs. HBC and the new members of contorted PAHs show trends in structure, optical properties, and an uncommon reaction with acids. This reversible reaction with acids modulates optical absorbance as well as electronic properties in thin films. The fifth, and final, chapter describes the investigation of much larger PAHs and graphene. First, large contorted PAHs appear to bridge the gap between small molecules and graphene. Then, a new method has afforded the efficient harvesting of graphene discs. Finally, a story of how a polymer might improve graphene transistors.

Tremblay, Noah Jonathan

282

Accumulation of mutagenic polycyclic aromatic hydrocarbons in biological sludge  

SciTech Connect

Research was conducted to study the lipophilic accumulation of mutagenic polycyclic aromatic hydrocarbons (PAH) in biological sludge produced during activated sludge treatment of fixed-bed coal-gasification wastewater. The activated sludge system was viewed as a two phase chemical system to model the PAH accumulation process, and PAH distribution in this system was quantified by an equilibrium distribution coefficient. A general equation was next developed from thermodynamic principles to predict a sludge lipid-gasifier wastewater distribution coefficient for any PAH of interest. Determination of the required parameters for this equation involved the use of a modified version of the UNIFAC method for calculating activity coefficients. PAH absorption isotherms for biological sludge in gasifier wastewater were determined by running a series of equilibrium absorption experiments. The results of these experiments indicated that the predictive equation accurately estimated distribution coefficients for most of the PAH tested. A bench scale activated sludge system treating gasifier wastewater was then operated to gather further data on PAH absorption.

Moretti, C.J.

1984-01-01

283

Polycyclic Aromatic Hydrocarbons Transformations in an Urban Fog  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons (PAHs) are generated from incomplete combustion of fuels, coal-fired power plants and other anthropogenic activities. These are ubiquitous in all environments, especially the atmosphere. PAHs generally are found in the gaseous form and associated with the particles in the atmosphere. They are also found in the atmospheric water present in the form of fog, mist, rain, snow and ice. Particles (aerosols) in the atmosphere invariably contain a thin film of water which tends to have a high affinity for the adsorption of gaseous PAHs. Molecular dynamic simulations clearly show that the air-water interface is a preferable surface for adsorption of large molecular weight PAHs and atmospheric oxidants (e.g., O3, OH, 1O2, NO3). Thus, photochemical transformation of adsorbed PAHs in fog droplets is a possibility in the atmosphere. This could lead to the formation of water-soluble oxy-PAHs which are potential precursors for secondary organic aerosols (SOAs). Field work in Baton Rouge and Houston combined with laboratory work in thin film reactors have shown that this hypothesis is substantially correct. Field data on fog and aerosols (pre- and post-fog) will be enumerated. Laboratory work and their implications will be summarized. The thin film surface environment resulted in enhanced reaction kinetics compared to bulk phase kinetics. The influence of surface reactions on the product compositions is evaluated by performing experiments with different film thicknesses.

Valsaraj, K.; Wornat, M. J.; Chen, J.; Ehrenhauser, F.

2010-07-01

284

Superconductivity in an Alkali Doped Polycyclic Aromatic Hydrocarbon, Picene  

NASA Astrophysics Data System (ADS)

The effect of carrier doping into polycyclic aromatic hydrocarbons, including perylene and pentacene, has been extensively studied.[1] As a result of halogen or alkali metal doping, a drastic increase in electrical conductivity was observed. However, superconductivity has not been reported except the one by Sch"on et al.[2] Recently, Kubozono reported that one of them, i.e. picene (C22H14) showed superconductivity at 20 K by doping with potassium.[3] We anticipate that it will lead to surprising findings of hidden organic molecular superconductors. In this presentation, we will report on the characterization of superconducting properties of alkali doped picene. Instead of ordinary vapor phase alkali metal doping, we employ thermal decomposition of alkali azides, i.e. AN3 where A = K, Rb. We followed the doping procedure of thermal decomposition applied to fullerene C60.[4] A systematic variation of the superconducting transition temperature and fraction are studied as a function of alkali metal composition. [1] H. Akamatu, H. Inokuchi, and Y. Matsunaga, Nature 173 (1954) 168. [2] J. H. Sch"on, Ch. Kloc & B. Batlogg, Nature 406 (2000) 702; retraction, Nature 422 (2003) 93. [3] R. Mitsuhashi, Y. Kubozono et al.: private communication. [4] M. Tokumoto, et al. , J. Phys. Chem. Solids, 54 (1993) 1667.

Tokumoto, Madoka; Shimizu, Fumihiko; Hata, Yoshiaki; Sawai, Shinya; Han, Jing; Inoue, Katsuya

2010-03-01

285

Atmospheric transport and outflow of polycyclic aromatic hydrocarbons from China  

SciTech Connect

A potential receptor influence function (PRIF) model, based on air mass forward trajectory calculations, was applied to simulate the atmospheric transport and outflow of polycyclic aromatic hydrocarbons (PAHs) emitted from China. With a 10 day atmospheric transport time, most neighboring countries and regions, as well as remote regions, were influenced by PAH emissions from China. Of the total annual PAH emission of 114 Gg, 92.7% remained within the boundary of mainland China. The geographic distribution of PRIFs within China was similar to the geographic distribution of the source regions, with high values in the North China Plain, Sichuan Basin, Shanxi, and Guizhou province. The Tarim basin and Sichuan basin had unfavorable meteorological conditions for PAH outflow. Of the PAH outflow from China (8092 tons or 7.1% of the total annual PAH emission), approximately 69.9% (5655 tons) reached no further than the offshore environment of mainland China and the South China Sea. Approximate 227, 71, 746, and 131 tons PAHs reached North Korea, South Korea, Russia-Mongolia region, and Japan, respectively, 2-4 days after the emission. Only 1.4 tons PAHs reached North America after more than 9 days. Interannual variation in the eastward PAH outflow was positively correlated to cold episodes of El Nino/Southern Oscillation. However, trans-Pacific atmospheric transport of PAHs from China was correlated to Pacific North America index (PNA) which is associated with the strength and position of westerly winds. 38 refs., 4 figs.

Chang Lang; Shu Tao; Wenxin Liu; Yanxu Zhang; Staci Simonich [Peking University, Beijing (China). Laboratory for Earth Surface Processes, College of Environmental Sciences

2008-07-15

286

Magnetic Beads-based Bioelectrochemical Immunoassay of Polycyclic Aromatic Hydrocarbons  

SciTech Connect

A simple, rapid, and sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) has been developed to detect polycyclic aromatic hydrocarbons (PAHs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PAH-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PAH (HRP-PAH). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreaction among PAH-antibody-coated MBs, PAH analyte, and HRP-PAH. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing 3, 3´, 5, 5´- tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) for electrochemical detection. The voltammetric characteristics of the substrate were investigated, and the reduction peak current of TMB was used to quantify the concentration of PAH. The different parameters, including the amount of HRP-PAH conjugates, the enzyme catalytic reaction time, and the pH of the supporting electrolyte that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 50 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical magnetic immunoassay was successfully evaluated with tap water spiked with PAHs, indicating that this convenient and sensitive technique offers great promise for decentralized environmental applications.

Lin, Ying-Ying; Liu, Guodong; Wai, Chien M.; Lin, Yuehe

2007-07-01

287

Polycyclic aromatic hydrocarbons in the atmosphere of the eastern Mediterranean.  

PubMed

Atmospheric processes governing the fate of the polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of the Eastern Mediterranean were studied for a two-year period (2000-2001). Atmospheric samples were collected off-shore over the Eastern Mediterranean Sea as well as at a background station in Northeastern Crete, Greece. PAH total concentration varied from 4.1 to 57.2 ng m(-3), with >90% in the gas phase. Gas-to-particle distribution of PAHs was correlated (R2 0.75-0.98, p < 0.001) with their subcooled vapor pressure. Seasonal changes in the total concentration of PAHs were not observed, while the origin of air mass was the dominant factor determining their atmospheric concentration levels. Air masses, originating from central and eastern Europe, were associated with the highest PAH concentrations. Gas-to-particle distribution of sigmaPAHs correlated well (R2 0.75-0.98, p < 0.001) with their subcooled vapor pressure. Tropospheric ozone concentration correlated with the vapor-phase PAH concentration (p < 0.001) but less (p < 0.01) with the particulate PAH concentration. Distribution of volatile PAHs over the Eastern Mediterranean basin was uniform. Conversely, particulate PAH concentrations were higher at sampling sites located close to urban centers. Calculated relative removal rates of PAHs associated with particles were significantly higher than those of volatile members. PMID:16190215

Tsapakis, Manolis; Stephanou, Euripides G

2005-09-01

288

Risk assessment of polycyclic aromatic hydrocarbons in aquatic ecosystems.  

PubMed

A probability risk assessment of anthracene, benzo(a)pyrene, chrysene, fluorene, phenanthrene and pyrene was carried out to examine the ecological risk of these six polycyclic aromatic hydrocarbons (PAHs) in aquatic ecosystems in China. The literature on PAH concentrations in surface water in China was collected to evaluate the environmental exposure concentrations (EEC). The 10th percentile of predicted no observed effect concentration (PNEC(10%)) of PAHs, calculated according to the data from the USEPA AQUIRE database and regulatory reviews, was applied as the toxicity assessment endpoint. The ratio of EEC and PNEC(10%), expressed as a risk quotient (RQ), was used to characterize the risk value. Bootstrapping method and Monte Carlo simulation were utilized to calculate the distribution of EEC, PNEC(10%), RQ and associated uncertainties. Risk assessment showed that reliable maximum RQs of anthracene, benzo(a)pyrene, chrysene, fluorene and phenanthrene were in the range of 0.064-0.755, lower than the acceptable value of 1. However, the reliable maximum RQ of pyrene was 1.39, indicating its potential ecological risk. Notwithstanding the uncertainty, these results suggest that the aquatic ecosystems with high PAH concentrations might pose potential ecological risks, and concerted efforts are required to ensure that surface water is protected. PMID:21431315

Wu, Bing; Zhang, Rui; Cheng, Shu-Pei; Ford, Timothy; Li, Ai-Min; Zhang, Xu-Xiang

2011-03-23

289

On the additivity of current density in polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Calculations of the ? current density for polycyclic aromatic hydrocarbons placed in a uniform magnetic field reveal in some cases a substantial localization on subunits. This localization can be anticipated either for molecules with a factorizable Kekulé count K, in light of some theoretical models of ring currents, or for system with proper symmetry, in light of magnetic group theory. We have addressed the problem of whether the localization is compatible with a description of the current density field as a sum of current density fields, studying the sum of two purely rotational fields. When this general model is specialized with the parameters taken from benzene ring current, it turns out that two corotating purely rotational fields separated by a distance comparable to a chemical bond must be separated by a saddle point. We have looked for the occurrence of this criterion in K-factorizable molecules, chosen according to a novel corollary to Kasteleyn's theorem, in coronenes, which have patterns localized by symmetry and in some further systems reported in literature. For those systems already described to have an additive current density pattern, the separating bonds do host saddle points, which are thus effective signatures of additivity.

Monaco, Guglielmo; Zanasi, Riccardo

2009-07-01

290

Bioaccessibility of polycyclic aromatic hydrocarbons: relevance to toxicity and carcinogenesis.  

PubMed

Introduction: Bioaccessibility is a growing area of research in the field of risk assessment. As polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, they are the toxicants of focus to establish cancer risks in humans. Orally ingested PAHs also cause toxicity and even affect the pharmacokinetic behavior of some therapeutic agents. Toward this end, bioaccessibility is being used as a tool to assess the risk of PAHs via dietary exposures. Areas covered: This review covers some in vitro bioaccessibility models for PAHs that have been used for the past one-and-a-half decade. This review also considers the factors that influence bioaccessibility and debates the merits and limitations of using a bioaccessibility concept for estimating risk from ingestion of PAH-contaminated soil and food. Finally, the authors discuss the implications of bioaccessibility for PAH-induced toxicity and cancers in the context of risk assessment. Expert opinion: So far, much of the focus on PAH bioaccessibility is centered on soil as a preferential matrix. However, ingestion of PAHs through diet far exceeds the amount accidentally ingested through soil. Therefore, bioaccessibility could be exploited as a tool to assess the relative risk of various dietary ingredients tainted with PAHs. While bioaccessibility is a promising approach for assessing PAH risk arising from various types of contaminated soils, none of the models proposed appears to be valid. Bioaccessibility values, derived from in vitro studies, still require validation from in vivo studies. PMID:23898780

Harris, Kelly L; Banks, Leah D; Mantey, Jane A; Huderson, Ashley C; Ramesh, Aramandla

2013-07-31

291

Laboratory Infrared Spectroscopy of Cationic Polycyclic Aromatic Hydrocarbon Molecules  

NASA Astrophysics Data System (ADS)

Infrared spectroscopy of a variety of interstellar sources shows strong mid-IR emission bands, which are generally attributed to emission from highly vibrationally excited polycyclic aromatic hydrocarbon molecules (PAHs) in the neutral and, particularly, cationic states. Over the past decade, various experimental methods have been developed to record the infrared spectra of cationic PAHs in the laboratory. In this paper, we discuss available experimental spectra obtained with matrix isolation spectroscopy (MIS), infrared multiple-photon dissociation of trapped ions (MPD), dissociation spectroscopy of ionic PAH van der Waals clusters (VDW), and infrared emission (IRE). Moreover, we compare these experimental spectra to density functional theory (DFT) calculations. The main body of experimental data relies on MIS and MPD spectra, and we present a detailed comparison of results from these methods, providing linear and multiple-photon absorption data, respectively. The effects of multiple-photon absorption, as encountered in MPD, and multiple-photon emission, occurring in interstellar spectra, are carefully assessed with the use of mathematical models, which include the effects of vibrational anharmonicity. We show that an analysis of the multiple-photon and linear data can provide important information on the anharmonicity parameters, which is otherwise difficult to attain. This is illustrated with a detailed comparison of the linear and multiple-photon absorption spectra of the naphthalene cation, yielding experimental anharmonicity parameters for the IR-active modes in the 500-1700 cm-1 range.

Oomens, Jos; Tielens, A. G. G. M.; Sartakov, Boris G.; von Helden, Gert; Meijer, Gerard

2003-07-01

292

Polycyclic aromatic hydrocarbons and fatal ischemic heart disease  

SciTech Connect

Several toxicologic and epidemiologic studies have produced evidence that occupational exposure to polycyclic aromatic hydrocarbons (PAH) is a risk factor for ischemic heart disease (IHD). However, a clear exposure-response relation has not been demonstrated. We studied a relation between exposure to PAH and mortality from IHD (418 cases) in a cohort of 12,367 male asphalt workers from Denmark, Finland, France, Germany, Israel, The Netherlands and Norway. Exposures to benzo(a)pyrene were assessed quantitatively using measurement-driven exposure models. Exposure to coal tar was assessed in a semiquantitative manner on the basis of information supplied by company representatives. We carried out sensitivity analyses to assess potential confounding by tobacco smoking. Both cumulative and average exposure indices for benzo(a)pyrene were positively associated with mortality from IHD. The highest relative risk for fatal IHD was observed for average benzo(a)pyrene exposures of 273 ng/m{sup 3} or higher, for which the relative risk was 1.64(95% confidence interval = 1.13-2.38). Similar results were obtained for coal tar exposure. Sensitivity analysis indicated that even in a realistic scenario of confounding by smoking, we would observe approximately 20% to 40% excess risk in IHD in the highest PAH-exposure categories. Our results lend support to the hypothesis that occupational PAH exposure causes fatal IHD and demonstrate a consistent exposure-response relation for this association.

Burstyn, I.; Kromhout, H.; Partanen, T.; Svane, O.; Langard, S.; Ahrens, W.; Kauppinen, T.; Stucker, I.; Shaham, J.; Heederik, D.; Ferro, G.; Heikkila, P.; Hooiveld, M.; Johansen, C.; Randem, B.G.; Boffetta, P. [International Agency for Research on Cancer, Lyon (France)

2005-11-01

293

Cardiac Autonomic Dysfunction from Occupational Exposure to Polycyclic Aromatic Hydrocarbons  

PubMed Central

Objectives Polycyclic aromatic hydrocarbons (PAHs) exposures have been associated with cardiopulmonary mortality and cardiovascular events. This study investigated the association between a biological marker of PAHs exposure, assessed by urinary 1-hydroxypyrene (1-OHP), and heart rate variability (HRV) in an occupational cohort of boilermakers. Methods Continuous 24-hour monitoring of the ambulatory electrocardiogram (ECG) and pre and post shift urinary 1-OHP were repeated over extended periods of the work week. Mixed effects models were fit for the 5-minute standard deviation of normal-to-normal intervals (SDNN) in relation to urinary 1-OHP levels pre and post workshift on the day they wore the monitor, controlling for potential confounders. Results We found a significant decrease in 5-min SDNN during work of ?13.6% (95% confidence interval, ?17.2% to ?9.8%) for every standard deviation (0.53 microgram/gram [?g/g] creatinine) increase in the next-morning pre-shift 1-OHP levels. The magnitude of reduction in 5-min SDNN were largest during the late night period after work and increased with every standard deviation (0.46 ?g/g creatinine) increase in post-shift 1-OHP levels. Conclusion This is the first report providing evidence that occupational exposure to PAHs is associated with altered cardiac autonomic function. Acute exposure to PAHs may be an important predictor of cardiovascular disease risk in the work environment.

Lee, Mi-Sun; Magari, Shannon; Christiani, David C.

2013-01-01

294

Uptake, translocation, and accumulation of polycyclic aromatic hydrocarbons in vegetation  

SciTech Connect

A review of the scientific literature was conducted to determine the potential for plants to take up polycyclic aromatic hydrocarbons (PAHs) from soils and the possibility of PAH movement from soils into vegetation at waste disposal sites associated with manufactured gas plants (MGP). Studies published since 1983 are considered in conjunction with previous publications and literature reviews on PAH uptake by vegetation. These studies indicate that the extent to which sorption to roots occurs is likely to be influenced by species-specific properties of the plant, physicochemical properties of each PAH, soil properties, and biodegradation rates of the PAHs in soil. PAHs containing five or more rings may sorb to plant roots but are not expected to be translocated to foliage in other than trace quantities. Uptake of naphthalene, anthracene, and benzo[a]anthracene by roots has been reported in the literature. In addition, eight PAHs of three and four rings (acenapthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, and chrysene) were isolated from leaves and roots of four plant species collected near a coal tar disposal trench in eastern Tennessee. A total concentration of 5519 ng/g was observed for the eight PAHs in roots of lamb's quarters. Coal tar, in soil, was implicated as the source of PAHs in the four plant species.

Walton, B.T. (Oak Ridge National Lab., TN (United States)); Hoylman, A.M. (Tennessee Univ., Knoxville, TN (United States))

1992-12-01

295

Biodegradation of polycyclic aromatic hydrocarbons by phanerochaete chrysosporium  

SciTech Connect

The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHs) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. Analysis by capillary gas chromatography and high-performance liquid chromatography showed that at least 22 PAHs, including all of the most abundant PAH components present in anthracene oil, underwent 70 to 100% disappearance during 27 days of incubation with nutrient nitrogen-limited cultures of this fungus. Because phenanthrene is the most abundant PAH present in anthracene oil, this PAH was selected for further study. In experiments in which ((14)C) phenanthrene was incubated with cultures of P. chrysosporium containing anthracene oil for 27 days, it was shown that 7.7% of the recovered radiolabeled carbon originally present in ((14)C) phenanthrene was metabolized to (14)CO2 and 25.2% was recovered from the aqueous fraction, while 56.1 and 11.0% were recovered from the methylene chloride and particulate fractions, respectively.

Bumpus, J.A.

1989-01-01

296

Biodegradation of polycyclic aromatic hydrocarbons by Phanerochaete chrysosporium  

SciTech Connect

The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHs) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. Analysis by capillary gas chromatography and high-performance liquid chromatography showed that at least 22 PAHs, including all of the most abundant PAH components present in anthracene oil, underwent 70 to 100% disappearance during 27 days of incubation with nutrient nitrogen-limited cultures of this fungus. Because phenanthrene is the most abundant PAH present in anthracene oil, this PAH was selected for further study. In experiments in which ({sup 14}C)phenanthrene was incubated with cultures of P. chrysosporium containing anthracene oil for 27 days, it was shown that 7.7% of the recovered radiolabeled carbon originally present in ({sup 14}C)phenanthrene was metabolized to {sup 14}CO{sub 2} and 25.2% was recovered from the aqueous fraction, while 56.1 and 11.0% were recovered from the methylene chloride and particulate fractions, respectively. High-performance liquid chromatography of the {sup 14}C-labeled material present in the methylene chloride fraction revealed that most (91.9%) of this material was composed of polar metabolites of ({sup 14}C)phenanthrene. These results suggest that this microorganism may be useful for the decontamination of sites in the environment contaminated with PAHs.

Bumpus, J.A. (Utah State Univ., Logan (USA))

1989-01-01

297

Mild extractability and bioavailability of polycyclic aromatic hydrocarbons in soil  

SciTech Connect

A study was conducted to determine the relationship between bioavailability of unaged and aged polycyclic aromatic hydrocarbons (PAHs) in soil and the amounts detected by mild solvent extraction. More aged than unaged anthracene remained in Lima loam following introduction of earthworms (Eisenia foetida), a mixed culture containing anthracene-degrading microorganisms, or earthworms or wheat after bacterial biodegradation of the compound. Aging decreased the percentage of anthracene recovered by mild extraction with n-butanol from soil following introduction of earthworms, growth of wheat, biodegradation by bacteria, or when maintained sterile. Biodegradation resulted in a marked decrease in the percentage of aged and unaged anthracene recovered from soil by mild extraction with n-butanol or ethyl acetate. Aging of fluoranthene and pyrene decreased the amount removed by mild extraction with n-butanol, ethyl acetate, and propanol. The uptake of aged and unaged anthracene, fluoranthene, and pyrene by earthworms was correlated with the amounts recovered from soil by mild extraction with n-butanol, propanol, and ethyl acetate. The retention of aged and unaged anthracene by wheat and barley was correlated with the amounts recovered from soil by the same procedure. The authors suggest that mild extraction with organic solvents can be used to predict the bioavailability of PAHs in soil.

Tang, J.; Alexander, M.

1999-12-01

298

Role of radical cations in aromatic hydrocarbon carcinogenesis.  

PubMed Central

Carcinogenic activation of polycyclic aromatic hydrocarbons (PAH) involves two main pathways: one-electron oxidation and monooxygenation. One-electron oxidation produces PAH radical cations, which can react with cellular nucleophiles. Results from biochemical and biological experiments indicate that only PAH with ionization potentials below ca. 7.35 eV can be metabolically activated by one-electron oxidation. In addition, the radical cations of carcinogenic PAH must have relatively high charge localization to react effectively with macromolecules in target cells. Metabolic formation of PAH quinones proceeds through radical cation intermediates. Binding of benzo[a]pyrene (BP) to mouse skin DNA occurs predominantly at C-6, the position of highest charge localization in the BP radical cation, and binding of 6-methyl BP to DNA in mouse skin yields a major adduct with the 6-methyl group bound to the 2-amino group of deoxyguanosine. Studies of carcinogenicity by direct application of PAH to rat mammary gland indicate that only PAH with ionization potentials low enough for activation by one-electron oxidation produce tumors in this target tissue. These constitute some of the results which provide evidence for the involvement of one-electron oxidation in PAH carcinogenesis.

Cavalieri, E; Rogan, E

1985-01-01

299

Atmospheric concentrations of polycyclic aromatic hydrocarbons during chimney sweeping.  

PubMed Central

Air sampled from the breathing zone of chimney sweeps during "dirty work" and soot samples were analysed for polycyclic aromatic hydrocarbons (PAH). A total of 20 PAH were quantified by gas chromatography-mass spectrometry in 115 air samples and 18 soot samples. These included benzo(b)fluoranthene, benzo(a)pyrene (BaP), chrysene, dibenz(a,h)anthracene, and indeno (1,2,3-cd)pyrene, all of which are animal carcinogens. The summed atmospheric concentration of these compounds depended on the type of fuel used and averaged 2.27 micrograms/m3 for oil fuel. If a mixture of oil and solid fuel was used the concentration was 5.06 micrograms/m3; pure solid fuel heating yielded 5.08 micrograms/m3. The air concentrations of BaP were 0.36, 0.83, and 0.82 micrograms/m3 respectively. The soot samples recovered after using the three different fuel types were 10.50, 109.10, and 51.25 mg BaP/kg. The maximum total concentrations of the five carcinogenic PAH were 243.70, 691.06, and 213.94 mg/kg respectively. The time weighted, shift mean concentrations of 0.02 to 0.21 micrograms/m3 benzo(a)pyrene obtained on 11 days form the basis for the industrial medical estimation of risk.

Knecht, U; Bolm-Audorff, U; Woitowitz, H J

1989-01-01

300

[The effect of polycyclic aromatic hydrocarbons to bone marrow].  

PubMed

Polycyclic aromatic hydrocarbons (PAH) represent a group of ubiquitous environmental pollutants. Their toxic effects are demonstrated mainly in tissues with high proliferation. The direct distribution of PAH in non-metabolized form to bone marrow and their biotransformation at this site to the toxic metabolites is necessary for demonstration of their toxic effect here. CYP1B1 that is constitutive expressed by stromal cells plays probably the main role in biotransformation of PAH in bone marrow. Reactions of toxic metabolites, development of oxidative stress and interference with intracellular calcium are ranged between the most important mechanisms of structural and functional changes of bone marrow after exposure to PAH. Pathological induction of apoptosis and malignant transformation of stem cells represent the concrete forms of bone marrow damage, caused by exposure to PAH. The bone marrow constitutes the central organ of hematopoiesis and the sites of production of cells of immune system. Its damage can bring therefore crucial health consequences for the whole organism. PMID:16106736

Hrudková, Monika; Fiala, Zdenek; Borská, Lenka; Novosad, Jakub; Smolej, Lukás

2004-01-01

301

Mutagenicity of transformation metabolites of selected polycyclic aromatic hydrocarbons  

SciTech Connect

The purpose of this study is: (1) to determine the efficacy of a microbial enhanced soil system in the degradation of selected polycyclic aromatic hydrocarbons (PAHs); (2) to determine if predictions based upon physical and chemical properties with respect to degree of recalcitrancy are borne out by observations in a laboratory environment; and (3) to determine the mutagenic potential of the degradation products by the Ames Mutagenicity Bioassay test. The two phase study examined the behavior of fluorene, benzo(b) fluoranthene, benzo(k) fluoranthene and dibenzo (a,h) anthracene in an enhanced soil system. The initial phase uses GC/MS analysis of both soil and water systems to determine if the PAHs had decreased in concentration. The final phase uses the Ames Bioassay to measure genotoxic potential. The results of the study suggest that benzo(k) fluoranthene produces mutagenic breakdown metabolites during microbial degradation and that volatilization is the significant loss mechanism for fluorene. Dibenzo(a,h) anthracene and benzo(b) fluoranthene are recalcitrant under the experimental conditions.

Paige, W.E. Jr.

1989-01-01

302

Polycyclic aromatic hydrocarbons in U. K. Urban air  

SciTech Connect

Polycyclic aromatic hydrocarbon (PAH) data for the first two years (January 1991-December 1992) of a national urban air monitoring scheme in the U.K. are presented. Urban sample sites were operated in the cities of London, Manchester, and Cardiff and in the light industrial town of Stevenage. Both the particulate and vapor phases of 15 PAHs were sampled using high-volume air samplers at roof-top level (approximately 25 m). London, the largest urban center, had the highest annual mean [Sigma]PAH concentrations of 166 ng/m[sup 3] in 1991. Phenanthrene and fluorene dominated the total PAH at each site and were present predominantly in the vapor phase throughout the year. The heavier PAHs (MW > 250) were present on the collected particulate and showed a distinct seasonal variation (winter > summer). PAH profiles were similar at each site, even though the conurbations were different in size, indicating sources common to each site. Specific atmospheric contamination episodes, associated with particular meteorological conditions, were identified throughout the 2-year period. NO[sub 2] concentrations were obtained for the Manchester site for 1991. Weak correlations (P [le] 0.05) were found to exist between elevated NO[sub 2] concentrations and particulate-benzo[a]pyrene and [Sigma]PAH concentrations. 40 refs., 4 figs., 3 tabs.

Halsall, C.J.; Burnett, V.; Waterhouse, K.S.; Jones, K.C. (Lancaster Univ. (United Kingdom)); Coleman, P.J.; Davis, B.J. (Warren Spring Lab., Stevenage (United Kingdom)); Harding-Jones, P. (Rechem Environmental Research, Southampton (United Kingdom))

1994-12-01

303

Oxidation of polynuclear aromatic hydrocarbons in water. 1: Ozonation  

SciTech Connect

The oxidation of three polynuclear aromatic hydrocarbons (PAHs), fluorene, phenanthrene, and acenaphthene, in aqueous solution with ozone has been studied. The influence of hydroxyl radical inhibitors, pH, ozone partial pressure, and temperature was investigated. All the PAHs studied show high oxidation rates with ozone. The ozonation of fluorene seems to be due to both direct and hydroxyl radical reactions while for the rest of the PAHs the ozonation develops only through direct reactions with ozone. Rate constants for the direct reaction between these PAHs and ozone have also been calculated. The reactivity with ozone goes in the following order: fluorene < phenanthrene < acenaphthene. The contribution of radical reactions represents more than 90% in the ozonation of fluorene in most cases except in the presence of hydroxyl radical inhibitors. In a standard agitated reactor the kinetic regime of the absorption of ozone corresponds to a slow reaction in the case of fluorene and phenanthrene and to a fast reaction in the case of acenaphthene.

Beltran, F.J.; Encinar, J.M.; Rivas, J. [Univ. de Extremadura, Badajoz (Spain). Dept. de Ingenieria Quimica y Energetica; Ovejero, G. [Univ. Complutense, Madrid (Spain). Dept. de Ingenieria Quimica

1995-05-01

304

Bioavailability of polycyclic aromatic hydrocarbons in the North Sea  

SciTech Connect

Semipermeable membrane devices (SPMDs) and blue mussels (Mytilus edulis) were used to determine the bioavailable fraction of polycyclic aromatic hydrocarbons (PAHs) from oil field produced water in the North Sea. The SPMDs and mussels were deployed at 5, 10, and 50 m depth; 100 and 300 m downstream the discharge point; and at a reference site 16 km away. In both SPMDs and mussels, the concentration of PAHs increased significantly toward the discharge point, with the strongest contribution from the lower molecular weight compounds (naphthalene, phenanthrene, dibenzothiophene, and their C1-C3 alkyl homologues). The relative increase in PAH concentration from the reference site to the site at 100 m was higher for mussels than for the SPMDs. The SPMDs reflect the water-soluble fraction of the PAHs, which is probably the most important route of exposure for organisms at lower trophic levels and presumably also the fraction available for uptake by a respiratory route. Residues in the mussels represent both the water-soluble and particle-bound fraction and give information about bioavailability of the PAHs for organisms at higher trophic levels. The results of this study suggest that both techniques give important information about the bioavailability of PAHs to marine organisms.

Utvik, T.I.R. (Norsk Hydro E and P Operations, Bergen (Norway). Environmental Section); Johnsen, S. (Statoil R and D Centre, Trondheim (Norway))

1999-06-15

305

Doped polycyclic aromatic hydrocarbons as building blocks for nanoelectronics: a theoretical study.  

PubMed

Density functional theory (DFT) and semiempirical UHF natural orbital configuration interaction (UNO-CI) calculations are used to investigate the effect of heteroatom substitution at the central position of a model polycyclic aromatic hydrocarbon. The effects of the substitution on structure, strain, electronic and spectral properties, and aromaticity of the compounds are discussed. PMID:23088568

Dral, Pavlo O; Kivala, Milan; Clark, Timothy

2012-10-31

306

Source identification of aromatic hydrocarbons in sediments using GC\\/MS  

Microsoft Academic Search

A method that may distinguish between input of polycyclic aromatic hydrocarbons (PAH) from petroleum and combustion sources is demonstrated on sediment samples. Selected series of aromatics (unsubstituted compounds and their Câ-Câ alkyl homologues) are quantified by computerized GC\\/MS. The alkyl homologue distribution (AHD) within each series and the sum of components in each series relative to the sum of all

S. Sporstoel; Nina Gjos; Rainer G. Lichtenthaler; Kay O. Gustavsen; Kjell Urdal; Froydis Oreld; J. Skel

1983-01-01

307

Slurry-Phase Ozonation for Remediation of Sediments Contaminated by Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic, persistent, bioaccumulating organic compounds containing two or more fused aromatic rings. They are listed by the U.S. Environmental Protection Agency as priority pollutants because of their carcinogenicity and toxicity. Employing ozonation as a remediation technique, this work investigated the treatability of a sediment sample from a freshwater boat slip subjected to

Yu Zeng; P. K. Andrew Hong

2002-01-01

308

The effects of polycyclic aromatic hydrocarbons on the immune system of fish: A review  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons are an important class of environmental pollutants that are known to be carcinogenic and immunotoxic. This review summarizes the diverse literature on the effects of these pollutants on innate and acquired immunity in fish and the mechanism of PAH-induced immunotoxicity. Among innate immune parameters, many authors have focused on macrophage activities in fish exposed to polycyclic aromatic

S. Reynaud; P. Deschaux

2006-01-01

309

Biodegradation of High-Molecular-Weight Polycyclic Aromatic Hydrocarbons by Bacteria  

Microsoft Academic Search

Interest in the biodegradation mechanisms and environ- mental fate of polycyclic aromatic hydrocarbons (PAHs) is prompted by their ubiquitous distribution and their potentially deleterious effects on human health. PAHs constitute a large and diverse class of organic compounds and are generally de- scribed as molecules which consist of three or more fused aromatic rings in various structural configurations (5). The

ROBERT A. KANALY; SHIGEAKI HARAYAMA

2000-01-01

310

INFLUENCE OF SOIL ORGANIC MATTER ON THE LEACHING OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOIL  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are one of the main classes of contaminants in the terrestrial environment. Aside from total organic carbon, the ratio among the different organic matter fractions [dissolved organic matter, fulvic acid (FA), humic acid (HA) and humin] can also affect the mobility of these hydrocarbons in soils. In this study the effect of the whole organic carbon

L. Petruzzelli; L. Celi; A. Cignetti; F. Ajmone Marsan

2002-01-01

311

Polycyclic aromatic hydrocarbons in the environment: homologous series in soils and recent marine sediments  

Microsoft Academic Search

Soils and recent marine sediments contain a complex polycyclic aromatic hydrocarbon assemblage. The many series of alkylhomologs have a similar molecular weight distribution, and it varies little over a wide range of depositional environments. It is suggested that these hydrocarbons are formed in natural fires, are dispersed and mixed by air transport and eventually deposited into surface sediments. The analytical,

W. W. Youngblood; M. Blumer

1975-01-01

312

Theoretical study of new acceptor and donor molecules based on polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Functionalized polycyclic aromatic hydrocarbons (PAHs) are an interesting class of molecules in which the electronic state of the graphene-like hydrocarbon part is tuned by the functional group. Searching for new types of donor and acceptor molecules, a set of new PAHs has recently been investigated experimentally using ultraviolet photoelectron spectroscopy (UPS). In this work, the electronic structure of the PAHs

S. Shahab Naghavi; Thomas Gruhn; Vajiheh Alijani; Gerhard H. Fecher; Claudia Felser; Katerina Medjanik; Dmytro Kutnyakhov; Sergej A. Nepijko; Gerd Schönhense; Ralph Rieger; Martin Baumgarten; Klaus Müllen

2011-01-01

313

Theoretical Study of New Acceptor and Donor Molecules based on Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Functionalized polcyclic aromatic hydrocarbons (PAHs) are an interesting class of molecules in which the electronic state of the graphene-like hydrocarbon part is tuned by the functional group. Searching for new types of donor and acceptor molecules, a set of new PAHs has recently been investigated experimentally using ultraviolet photoelectron spectroscopy (UPS). In this work, the electronic structure of the PAHs

S. Shahab Naghavi; Thomas Gruhn; Vajiheh Alijani; Gerhard H. Fecher; Claudia Felser; Katerina Medjanik; Dmytro Kutnyakhov; Sergej A. Nepijko; Ralph Rieger; Martin Baumgarten

2010-01-01

314

Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China  

Microsoft Academic Search

Spatial distribution of chlorinated hydrocarbons [chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs)] and polycyclic aromatic hydrocarbons (PAHs) was measured in riverine and estuarine sediment samples from Pearl River Delta, China, collected in 1997. Concentrations of CPs of the riverine sediment samples range from 12 to 158 ng\\/g, dry weight, while those of PCBs range from 11 to 486 ng\\/g. The

Bi-Xian Mai; Jia-Mo Fu; Guo-Ying Sheng; Yue-Hui Kang; Zheng Lin; Gan Zhang; Yu-Shuan Min; Eddy Y. Zeng

2002-01-01

315

Organochlorine contaminants in fish and polycyclic aromatic hydrocarbons in sediments from the Barents Sea  

Microsoft Academic Search

Stange, K., and Klungsøyr, J. 1997. Organochlorine contaminants in fish and poly- cyclic aromatic hydrocarbons in sediments from the Barents Sea. - ICES Journal of Marine Science, 54: 318-332. Sediment samples from 140 locations in the Barents Sea were analysed for diaromatic and polyaromatic hydrocarbons (PAHs). The concentrations found were lower than typical levels found at more southern latitudes such

Kari Stange; Jarle Klungsøyr

1997-01-01

316

Polycyclic aromatic hydrocarbons in the atmosphere of Shanghai, China.  

PubMed

Shanghai is the largest industrial and commercial city in China, and its air quality has been concerned for several years. However, scarce study had been made on the seasonal levels of atmospheric polycyclic aromatic hydrocarbons (PAHs), together with their gas-particle partitioning and potential emission sources. Based on an intensive sampling campaign at urban and suburban areas in Shanghai during four seasons of 2005-2006, this study presented the measurement of PAH concentrations in both particulate and gaseous phases, as well as seasonal and spatial variability. The results showed that the annual PAH levels (gas + particle) were 167 ± 109 ng m?³ at the urban site and 216 ± 86.5 ng m?³ at the suburban site. Gaseous PAHs (>70%) dominated the total PAH mass at both sites, while particulate PAHs contributed more than 90% of the toxic power according to benzo(a)pyrene-equivalent carcinogenic parameter. Different seasonal trend of PAH concentrations was observed between the two sites, and it may be explained by complicated factors such as sampling heights, local/regional emission sources, and climatic conditions. The gas-particle partitioning of PAHs in all samples was calculated, and strong linear correlations between log K (p) and log P(L)° were observed, with shallower slopes (m(r)) at the suburban site than the urban one and in warm season than the cold months, indicating the different equilibrium conditions of PAHs in spatial and seasonal scales in Shanghai. The slope (m(r)?=?-?0.96) and correlation coefficient (R²?= 0.81) for four-ring PAHs were closest to theoretical equilibrium conditions among compounds with various aromatic rings. Finally, the potential PAH sources were estimated based on principal factor analysis with multiple linear regressions. Ground volatilization dominated the PAH pollutions at both sites, while vehicles and coal consumption were the other main emission sources, which totally contributed 32.0% (suburban) to 49.2% (urban) of PAH mass in Shanghai atmosphere. The effects of wood and biomass burning were also detected, but their contributions to PAHs were negligible. PMID:20145995

Chen, Yingjun; Feng, Yanli; Xiong, Shengchun; Liu, Dongyan; Wang, Gang; Sheng, Guoying; Fu, Jiamo

2010-02-10

317

Aromatic hydrocarbon optrodes for groundwater monitoring applications. Final report, September 1988-February 1990  

SciTech Connect

Research documented in this report produced a fiber-optic sensor utilizing a porous optical waveguide. This offered the advantage of improved sensitivity and specificity by impregnating fiber with a chemical indicator whose optical transmission properties change in the presence of aromatic species. The concept was adequately demonstrated the laboratory and a prototype optrode was developed which was sensitive for aromatic hydrocarbons to 50 ppb. The basic concept was proven. Fiber-optic sensor, Groundwater monitoring, Aromatic hydrocarbon optrodes, Porous glass xylene sensor, Chemical sensors, Evanescent fiber-optic sensor.

Tabacco, M.B.

1993-12-01

318

Measurement of Atmospheric Monocyclic Aromatic Hydrocarbons and Chlorinated C1- and C2Hydrocarbons at NG.M Concentration Levels  

Microsoft Academic Search

An air sampling and analysis technique for thirteen monocyclic aromatic hydrocarbons (MAHs) and chlorinated C1- and C2-hydrocarbons (CHCs) at ng.m concentration levels is presented. Sampling was done on Carbopack B\\/Carbosieve SIII adsorbent tubes. The analysis on an automated on-line purge and trap (P&T) apparatus equipped with a thermal desorption unit proved to be not reproducible because of water interference and

J. Dewulf; D. Ponnet; H. Van Langenhove

1996-01-01

319

Spectroscopic and vibronic properties of dehydrogenated polycyclic aromatic hydrocarbons and honeycomb carbon clusters  

NASA Astrophysics Data System (ADS)

Spectroscopic and vibronic properties of dehydrogenated polycyclic aromatic hydrocarbons and hexagonal carbon clusters have been calculated and compared on the basis of the MO/8E method which has been developed as a convenient technique for vibrational and vibronic properties of benzenoid polycyclic hydrocarbons with honeycomb carbon network. IR spectra of C6Hx (x=0-6) crucially depend on the structures, whereas vibronic spectra are rather similar between an aromatic hydrocarbon such as C6H6 and C24H12 and their dehydrogenated species or the corresponding carbon cluster.

Yamada, Megumi; Ohno, Koichi

2006-09-01

320

Absorption cross section at 3.39 ?m of alkanes, aromatics and substituted hydrocarbons  

NASA Astrophysics Data System (ADS)

The present study reports gas phase absorption cross sections at 3.39 ?m of 21 liquid hydrocarbons. Measurements were performed in the temperature range 303-413 K using an infrared He-Ne laser. In addition to n-alkanes, a number of cyclo-alkane, aromatic, and substituted hydrocarbons were investigated. The results demonstrate that (i) the absorption cross sections are temperature independent in the studied range, and that (ii) the aromatic and substituted hydrocarbons exhibit much smaller cross sections than n-alkanes for an identical number of C-H bonds. A tentative empirical correlation has been developed and shown to accurately predicts the cross section.

Mével, R.; Boettcher, P. A.; Shepherd, J. E.

2012-04-01

321

Fluorescence quenching of vaporous polycyclic aromatic hydrocarbons by oxygen  

NASA Astrophysics Data System (ADS)

The fluorescence quenching by oxygen of vapors of nine polycyclic aromatic hydrocarbons with strongly different oxidation potentials 0.44 eV < E ox < 1.61 eV (anthracene, 9-methylanthracene, 2-aminoanthracene, 9,10-dibromanthracene, pyrene, chrysene, phenanthrene, fluoranthene, and carbazole) is studied. From the dependences of the fluorescence decay rates and intensities on the oxygen pressure P O2, the quenching rate constants k S O2 for the excited singlet states S 1 and the fraction f S O2 of the S 1 states quenched by oxygen are estimated. At P O2 = 5 Torr, the k S O2 constants vary from 1.2 × 107 to 3.0 × 105 s-1 Torr-1, while the fraction of the quenched excited singlet states changes from 0.1 (fluoranthene) to 0.7 (chrysene) and 0.8 (pyrene). The dependences of k S O2 on the photophysical and electron-donor characteristics of the fluorescing compounds are analyzed. It is shown that, in the gas phase of anthracene and its derivatives, the magnitudes of k S O2 are limited by the rate constants of gas-kinetic collisions k gk and do not depend on the electron-donor characteristics of fluorophores, while the fraction of quenched states f S O2 changes with the oxidation potential. For compounds with k S O2 < k gk, both the rate constants k S O2 and the fraction of quenched states f S O2 depend on the E ox of sensitizers, which demonstrates an important role played by the charge-transfer interactions in quenching of the S 1 states. The dependence of the rate constants k S O2 on the free energy of electron transfer ?G et is considered.

Zalesskaya, G. A.; Piuzzi, F.; Sambor, E. G.

2007-04-01

322

Sorption characteristics of polycyclic aromatic hydrocarbons in aluminum smelter residues  

SciTech Connect

High temperature carbon oxidation in primary aluminum smelters results in the release of polycyclic aromatic hydrocarbons (PAH) into the environment. The main source of PAH are the anodes, which are composed of petroleum coke (black carbon, BC) and coal tar pitch. To elucidate the dominant carbonaceous phase controlling the environmental fate of PAH in aluminum smelter residues (coke BC and/or coal tar), the sorptive behavior of PAHs has been determined, using passive samplers and infinite-sink desorption methods. Samples directly from the wet scrubber were studied as well as ones from an adjacent 20-year old storage lagoon and roof dust from the smelter. Carbon-normalized distribution coefficients of native PAHs were 2 orders of magnitude higher than expected based on amorphous organic carbon (AOC)/water partitioning, which is in the same order of magnitude as reported literature values for soots and charcoals. Sorption isotherms of laboratory-spiked deuterated phenanthrene showed strong (about 100 times stronger than AOC) but nonetheless linear sorption in both fresh and aged aluminum smelter residues. The absence of nonlinear behavior typical for adsorption to BC indicates that PAH sorption in aluminum smelter residues is dominated by absorption into the semi-solid coal tar pitch matrix. Desorption experiments using Tenax showed that fresh smelter residues had a relatively large rapidly desorbing fraction of PAH (35-50%), whereas this fraction was strongly reduced (11-16%) in the lagoon and roof dust material. Weathering of the coal tar residue and/or redistribution of PAH between coal tar and BC phases could explain the reduced availability in aged samples. 38 refs., 5 figs., 1 tab.

Gijs D. Breedveld; Emilien Pelletier; Richard St. Louis; Gerard Cornelissen [Norwegian Geotechnical Institute, Oslo (Norway)

2007-04-01

323

Biodegradation of polycyclic aromatic hydrocarbons by a halophilic microbial consortium.  

PubMed

In this study we investigated the phenanthrene degradation by a halophilic consortium obtained from a saline soil sample. This consortium, named Qphe, could efficiently utilize phenanthrene in a wide range of NaCl concentrations, from 1% to 17% (w/v). Since none of the purified isolates could degrade phenanthrene, serial dilutions were performed and resulted in a simple polycyclic aromatic hydrocarbon (PAH)-degrading culture named Qphe-SubIV which was shown to contain one culturable Halomonas strain and one unculturable strain belonging to the genus Marinobacter. Qphe-SubIV was shown to grow on phenanthrene at salinities as high as 15% NaCl (w/v) and similarly to Qphe, at the optimal NaCl concentration of 5% (w/v), could degrade more than 90% of the amended phenanthrene in 6 days. The comparison of the substrate range of the two consortiums showed that the simplified culture had lost the ability to degrade chrysene but still could grow on other polyaromatic substrates utilized by Qphe. Metabolite analysis by HPLC and GC-MS showed that 2-hydroxy 1-naphthoic acid and 2-naphthol were among the major metabolites accumulated in the Qphe-SubIV culture media, indicating that an initial dioxygenation step might proceed at C1 and C2 positions. By investigating the growth ability on various substrates along with the detection of catechol dioxygenase gene, it was postulated that the uncultured Marinobacter strain had the central role in phenanthrene degradation and the Halomonas strain played an auxiliary role in the culture by utilizing phenanthrene metabolites whose accumulation in the media could be toxic. PMID:22086071

Dastgheib, Seyed Mohammad Mehdi; Amoozegar, Mohammad Ali; Khajeh, Khosro; Shavandi, Mahmoud; Ventosa, Antonio

2011-11-16

324

Human Colon Microbiota Transform Polycyclic Aromatic Hydrocarbons to Estrogenic Metabolites  

PubMed Central

Ingestion is an important exposure route for polycyclic aromatic hydrocarbons (PAHs) to enter the human body. Although the formation of hazardous PAH metabolites by human biotransformation enzymes is well documented, nothing is known about the PAH transformation potency of human intestinal microbiota. Using a gastrointestinal simulator, we show that human intestinal microbiota can also bioactivate PAHs, more in particular to estrogenic metabolites. PAH compounds are not estrogenic, and indeed, stomach and small intestine digestions of 62.5 nmol naphthalene, phenanthrene, pyrene, and benzo(a)pyrene showed no estrogenic effects in the human estrogen receptor bioassay. In contrast, colon digests of these PAH compounds displayed estrogenicity, equivalent to 0.31, 2.14, 2.70, and 1.48 nmol 17?-ethynylestradiol (EE2), respectively. Inactivating the colon microbiota eliminated these estrogenic effects. Liquid chromatography–mass spectrometry analysis confirmed the microbial PAH transformation by the detection of PAH metabolites 1-hydroxypyrene and 7-hydroxybenzo(a)pyrene in colon digests of pyrene and benzo(a)pyrene. Furthermore, we show that colon digests of a PAH-contaminated soil (simulated ingestion dose of 5 g/day) displayed estrogenic activity equivalent to 0.58 nmol EE2, whereas stomach or small intestine digests did not. Although the matrix in which PAHs are ingested may result in lower exposure concentrations in the gut, our results imply that the PAH bioactivation potency of colon microbiota is not eliminated by the presence of soil. Moreover, because PAH toxicity is also linked to estrogenicity of the compounds, the PAH bioactivation potency of colon microbiota suggests that current risk assessment may underestimate the risk from ingested PAHs.

Van de Wiele, Tom; Vanhaecke, Lynn; Boeckaert, Charlotte; Peru, Kerry; Headley, John; Verstraete, Willy; Siciliano, Steven

2005-01-01

325

Strong Polycyclic Aromatic Hydrocarbon Emission from z ? 2 ULIRGs  

NASA Astrophysics Data System (ADS)

Using the Infrared Spectrograph on board the Spitzer Space Telescope, we present low-resolution (64 < ?/?? < 124), mid-infrared (20-38 ?m) spectra of 23 high-redshift ULIRGs detected in the Boötes field of the NOAO Deep Wide-Field Survey. All of the sources were selected to have (1) f ?(24 ?m)>0.5 mJy; (2) R - [24]>14 Vega mag; and (3) a prominent rest frame 1.6 ?m stellar photospheric feature redshifted into Spitzer's 3-8 ?m IRAC bands. Of these, 20 show emission from polycyclic aromatic hydrocarbons (PAHs), usually interpreted as signatures of star formation. The PAH features indicate redshifts in the range 1.5 < z < 3.0, with a mean of langzrang = 1.96 and a dispersion of 0.30. Based on local templates, these sources have extremely large infrared luminosities, comparable to that of submillimeter galaxies. Our results confirm previous indications that the rest-frame 1.6 ?m stellar bump can be efficiently used to select highly obscured star-forming galaxies at z ? 2, and that the fraction of starburst-dominated ULIRGs increases to faint 24 ?m flux densities. Using local templates, we find that the observed narrow redshift distribution is due to the fact that the 24 ?m detectability of PAH-rich sources peaks sharply at z = 1.9. We can analogously use observed spectral energy distributions to explain the broader redshift distribution of Spitzer-detected ULIRGs that are dominated by an active galactic nucleus (AGN). Finally, we conclude that z ? 2 sources with a detectable 1.6 ?m stellar opacity feature lack sufficient AGN emission to veil the 7.7 ?m PAH band. Based on observations made with the Spitzer Space Telescope, operated by the Jet Propulsion Laboratory under NASA contract 1407.

Desai, Vandana; Soifer, B. T.; Dey, Arjun; Le Floc'h, Emeric; Armus, Lee; Brand, Kate; Brown, Michael J. I.; Brodwin, Mark; Jannuzi, Buell T.; Houck, James R.; Weedman, Daniel W.; Ashby, Matthew L. N.; Gonzalez, Anthony; Huang, Jiasheng; Smith, Howard A.; Teplitz, Harry; Willner, Steve P.; Melbourne, Jason

2009-08-01

326

Background'' soil concentration of polycyclic aromatic hydrocarbons from Burlington, Vermont  

SciTech Connect

Polycyclic Aromatic Hydrocarbons (PAH's) were identified in soils from waterfront industrial land in Burlington prior to conversion to a park. PAH's ranged from 2,457 to 16,005 ppb. As a result, this area was placed on the Vt. DEC list of active'' hazardous sites. The few studies available regarding background concentrations of PAH's (i.e. ATSDR, 1990), suggested that the waterfront PAH values were low for urban soils. To provide a context for evaluating the waterfront PAH concentrations, a background study of soils in the City of Burlington was conducted. Twelve composite soil samples were collected from within a 1-mile radius of the proposed park; an area that encompasses a large portion of the City. To correlate PAH concentrations with land-uses, three samples were collected from each of four zones: industrial, mixed commercial-residential, residential and recreational. Samples (and one field blank) were analyzed via EPA method 8100. Total PAH's from the study ranged from 105.7 to 122,035 ppb. The minimum value was from a baseball field; the maximum value from a residential lawn. The arithmetic mean for the Burlington study was 19,380 ppb (compared to 10,530 ppb for the waterfront). The background'' values indicate that the waterfront park soils are below the study background'' mean. It is difficult to assess the origin of the elevated PAH values because of the numerous contributors of environmental PAH. One common element that appears to characterize soils with the highest background'' PAH values is linkage to recent or historic building fires. In many instances building combustion may be a dominant local source of soil PAH's.

Parker, R.L.; Sparks, M.K. (Wagner, Heindel and Noyes, Inc., Burlington, VT (United States))

1993-03-01

327

Engineered antibodies for monitoring of polynuclear aromatic hydrocarbons  

SciTech Connect

'The long-term goal of this project is to develop antibodies and antibody-based methods for detection and recovery of polynuclear aromatic hydrocarbons (PAHs) and PAH adducts that are potential biomarkers in environmental and biological samples. The inherent cross-reactivity will be exploited by pattern recognition methods. Dr. Karu''s laboratory uses new haptens representing key PAHs to derive recombinant Fab (rFab) and single-chain Fv (scFv) antibodies from hybridoma lines and combinatorial phage display libraries. Computational models of the haptens and combining sites made by Dr. Roberts''s group are used to guide antibody engineering by mutagenesis. Dr. Li''s laboratory develops enzyme immunoassays (EIAs), sensors, and immunoaffinity methods that make use of the novel haptens and antibodies for practical analytical applications in support of DOE''s mission. This report summarizes work completed in one and one-half years of a 3-year project, with close collaboration between the three research groups. Dr. Alexander Karu''s laboratory: the authors proceeded with the two strategies described in the original proposal. Site-directed mutagenesis was used to correct differences in the rFab N-terminal amino acids that were introduced by the degenerate PCR primers used for gene amplification. The binding constants of the rFabs with the corrected sequences will be compared with those of the parent MAbs, and should be very similar. The 4D5 and 10C10 heavy and light chain sequences are being moved to the pCOMB3H phagemid vector to facilitate selection of new engineered mutants.'

Karu, A.E. [Univ. of California, Berkeley, CA (US); Roberts, V.A. [Scripps Research Inst., La Jolla, CA (US); Li, Q.X. [Univ. of Hawaii, Honolulu, HI (US)

1998-06-01

328

STRONG POLYCYCLIC AROMATIC HYDROCARBON EMISSION FROM z {approx} 2 ULIRGs  

SciTech Connect

Using the Infrared Spectrograph on board the Spitzer Space Telescope, we present low-resolution (64 < {lambda}/{delta}{lambda} < 124), mid-infrared (20-38 {mu}m) spectra of 23 high-redshift ULIRGs detected in the Booetes field of the NOAO Deep Wide-Field Survey. All of the sources were selected to have (1) f {sub {nu}}(24 {mu}m)>0.5 mJy; (2) R - [24]>14 Vega mag; and (3) a prominent rest frame 1.6 {mu}m stellar photospheric feature redshifted into Spitzer's 3-8 {mu}m IRAC bands. Of these, 20 show emission from polycyclic aromatic hydrocarbons (PAHs), usually interpreted as signatures of star formation. The PAH features indicate redshifts in the range 1.5 < z < 3.0, with a mean of (z) = 1.96 and a dispersion of 0.30. Based on local templates, these sources have extremely large infrared luminosities, comparable to that of submillimeter galaxies. Our results confirm previous indications that the rest-frame 1.6 {mu}m stellar bump can be efficiently used to select highly obscured star-forming galaxies at z {approx} 2, and that the fraction of starburst-dominated ULIRGs increases to faint 24 {mu}m flux densities. Using local templates, we find that the observed narrow redshift distribution is due to the fact that the 24 {mu}m detectability of PAH-rich sources peaks sharply at z = 1.9. We can analogously use observed spectral energy distributions to explain the broader redshift distribution of Spitzer-detected ULIRGs that are dominated by an active galactic nucleus (AGN). Finally, we conclude that z {approx} 2 sources with a detectable 1.6 {mu}m stellar opacity feature lack sufficient AGN emission to veil the 7.7 {mu}m PAH band.

Desai, Vandana; Soifer, B. T.; Melbourne, Jason [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Dey, Arjun; Brand, Kate; Brodwin, Mark; Jannuzi, Buell T. [National Optical Astronomy Observatory, Tucson, AZ 85726-6732 (United States); Le Floc'h, Emeric [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Armus, Lee; Teplitz, Harry [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Brown, Michael J. I. [School of Physics, Monash University, Clayton, Victoria 3800 (Australia); Houck, James R.; Weedman, Daniel W. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Ashby, Matthew L. N.; Huang Jiasheng; Smith, Howard A.; Willner, Steve P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gonzalez, Anthony [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States)

2009-08-01

329

Sorption characteristics of polycyclic aromatic hydrocarbons in aluminum smelter residues.  

PubMed

High temperature carbon oxidation in primary aluminum smelters results in the release of polycyclic aromatic hydrocarbons (PAH) into the environment. The main source of PAH are the anodes, which are composed of petroleum coke (black carbon, BC) and coal tar pitch. To elucidate the dominant carbonaceous phase controlling the environmental fate of PAH in aluminum smelter residues (coke BC and/or coal tar), the sorptive behavior of PAHs has been determined, using passive samplers and infinitesink desorption methods. Samples directly from the wet scrubber were studied as well as ones from an adjacent 20-year old storage lagoon and roof dust from the smelter. Carbon-normalized distribution coefficients of native PAHs were 2 orders of magnitude higher than expected based on amorphous organic carbon (AOC)/water partitioning, which is in the same order of magnitude as reported literature values for soots and charcoals. Sorption isotherms of laboratory-spiked deuterated phenanthrene showed strong (-100 times stronger than AOC) but nonetheless linear sorption in both fresh and aged aluminum smelter residues. The absence of nonlinear behavior typical for adsorption to BC indicates that PAH sorption in aluminum smelter residues is dominated by absorption into the semi-solid coal tar pitch matrix. Desorption experiments using Tenax showed that fresh smelter residues had a relatively large rapidly desorbing fraction of PAH (35-50%), whereas this fraction was strongly reduced (11-16%) in the lagoon and roof dust material. Weathering of the coal tar residue and/or redistribution of PAH between coal tar and BC phases could explain the reduced availability in aged samples. PMID:17438813

Breedveld, Gijs D; Pelletier, Emilien; St Louis, Richard; Cornelissen, Gerard

2007-04-01

330

Occurrence of polycyclic aromatic hydrocarbons throughout the processing stages of erva-mate (Ilex paraguariensis).  

PubMed

The presence of polycyclic aromatic hydrocarbons (PAHs) in mate (Ilex paraguariensis) is believed to be due to the degradation of mate compounds and the burning of wood during the "sapeco" (rapid drying process) and the final drying steps, which are the most important processing stages in mate production. Due to the high toxicity of these compounds, studies on their presence in mate are extremely important. The aim of this study was to evaluate PAH levels in mate throughout the processing stages of its production. The PAHs were measured in samples collected at different stages of mate processing. Total PAHs content ranged widely (443-9001 microg/kg) in the samples, with the highest PAHs levels recorded during the mate drying step. The results indicate that the processing method currently used in mate production may lead to an increase in PAHs levels in the final product. PMID:20349373

Vieira, Manoela Alano; Maraschin, Marcelo; Rovaris, Angela Angeloni; Amboni, Renata Dias de Mello Castanho; Pagliosa, Cristiane Manfé; Xavier, José Júnior Mendonca; Amante, Edna Regina

2010-06-01

331

Polycyclic aromatic hydrocarbons in ash: determination of total and leachable concentrations.  

PubMed

Before wood ash can be used as a soil fertilizer, concentrations of environmentally hazardous compounds must be investigated. In this study, total and leachable concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in four ash samples and one green liquor sludge. The ash sample with the highest carbon content also contained high levels of PAHs; three of the ash samples had total concentrations exceeding the limit permitted by the Swedish Forest Agency for recycling to forest soils. The leachable concentrations were higher for the non-stabilized samples; this was probably due to colloid-facilitated transport of the contaminants in these samples. However, the leachable concentrations were overall relatively low in all the samples studied. The amounts of PAHs introduced to forest soils by additions of stabilized, recyclable ash products will be determined primarily by the rate of weathering of the ash particles and the total concentration of contaminants. PMID:17719155

Enell, Anja; Fuhrman, Filippa; Lundin, Lisa; Warfvinge, Per; Thelin, Gunnar

2007-08-24

332

THE EFFECTS OF EQUIVALENCE RATIO ON THE FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND SOOT IN PREMIXED ETHANE FLAMES. (R825412)  

EPA Science Inventory

Abstract The formation of polycyclic aromatic hydrocarbons (PAH) and soot has been investigated in atmospheric-pressure, laminar, ethane/oxygen/argon premixed flames as a function of mixture equivalence ratio. Mole fraction profiles of major products, trace aromatics, ...

333

Nitrated polycyclic aromatic hydrocarbons and azaarenes induce cytochrome P4501A in a fish hepatoma cell line  

Microsoft Academic Search

Nitrated polycyclic aromatic hydrocarbons (NPAH) and N-heterocyclic aromatic hydrocarbons (azaarenes) are as ubiquitous in the environment as their parent polycyclic aromatic hydrocarbon (PAH) compounds, although concentrations are commonly lower. Some of the NPAH and azaarenes are carcinogenic in mammals. Little is known, however, about their carcinogenicity and cytochrome P4501A (CYP1A) induction potency in fish. In this study, CYP1A induction potencies,

K. Fent; D. K. J. Jung

2000-01-01

334

Desulfurization of diesel fuels by selective adsorption on activated carbons: Competitive adsorption of polycyclic aromatic sulfur heterocycles and polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Adsorptive affinity of polycyclic aromatic sulfur heterocycles (PASHs) and polycyclic aromatic hydrocarbons (PAHs) on activated carbons and the effect of PAHs on the adsorption performance of PASHs were studied. Adsorptions of real and model diesels (MDs) containing aromatics and sulfur compounds over several activated carbons were conducted in both batch and fixed-bed adsorption systems. The adsorption results showed that adsorptive

Jie Bu; Chuandayani Gunawan Gwie; Silvia Dewiyanti; Michael Tasrif; Armando Borgna

2011-01-01

335

Polycyclic aromatic hydrocarbon (PAH) burden of mussels ( Mytilus sp.) in different marine environments in relation with sediment PAH contamination, and bioavailability  

Microsoft Academic Search

Sediments and mussels (Mytilus edulis, Mytilus galloprovincialis) were sampled in different European coastal environments (Germany, France, Spain) and analysed for their polycyclic aromatic hydrocarbon (PAH) content by Gas Chromatography\\/Mass Spectrometry (GC-MS). Bioaccumulation factors of individual compounds from the sediment were calculated and discussed according to the compound solubility. The mussels showed different accumulation patterns according to the pollution source they

P Baumard; H Budzinski; P Garrigues; J. F Narbonne; T Burgeot; X Michel; J Bellocq

1999-01-01

336

Fate of aromatic hydrocarbons in Italian municipal wastewater systems: An overview of wastewater treatment using conventional activated-sludge processes (CASP) and membrane bioreactors (MBRs)  

Microsoft Academic Search

We studied the occurrence, removal, and fate of 16 polycyclic aromatic hydrocarbons (PAHs) and 23 volatile organic compounds (VOCs) in Italian municipal wastewater treatment systems in terms of their common contents and forms, and their apparent and actual removal in both conventional activated-sludge processes (CASP) and membrane bioreactors (MBRs). We studied five representative full-scale CASP treatment plants (design capacities of

Francesco Fatone; Silvia Di Fabio; David Bolzonella; Franco Cecchi

2011-01-01

337

Trace level determination of polycyclic aromatic hydrocarbons in river water with automated pretreatment HPLC.  

PubMed

A novel on-line pretreatment pump-injection HPLC system for polycyclic aromatic hydrocarbons is proposed. We report novel pump-injection HPLC-based on-line SPE with a specially designed pretreatment column for the determination of trace amounts of chemical substances in surface water. Polycyclic aromatic hydrocarbons are well known for strong carcinogenicity and thus a severe concentration control is required for drinking water and/or river water, which is the main resource of tap water. We found it possible to detect ng/L levels of polycyclic aromatic hydrocarbons by using pump-injection column switching HPLC with fluorescence detection. To avoid the phenomenon, in which polycyclic aromatic hydrocarbons can be often adsorbed on the surface of flow lines of HPLC by their highly hydrophobicity especially resin-made parts in sample delivery pump, we employed "autodilution" device that provides reliable recovery and repeatability. Additionally, real water samples were collected and then the spiked polycyclic aromatic hydrocarbons were determined at ng/L levels. PMID:23427143

Watabe, Yoshiyuki; Kubo, Takuya; Tanigawa, Tetsuya; Hayakawa, Yoshihiro; Otsuka, Koji; Hosoya, Ken

2013-02-21

338

Determination of aromatic hydrocarbons in bituminous emulsion sealants using headspace solid-phase microextraction and gas chromatography-mass spectrometry.  

PubMed

The possibility of quantitative determination of aromatic hydrocarbons in bituminous emulsion sealants was investigated using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). The target analytes studied were benzene, toluene, ethylbenzene, p-, m-, and o-xylene (BTEX) as well as 1,3,5- and 1,2,4-trimethylbenzene. Experimental factors influencing HS-SPME efficiency were studied (sample-headspace equilibration time, extraction time and sample matrix effects). A HS-SPME method using surrogate matrix was developed. The detection limit was estimated as approximately 0.1 ppmw for the target analytes investigated. Good linearity was observed (R(2)>0.997) for all calibration curves obtained. The repeatability of the method (RSD, relative standard deviation) was found less than 10%. The accuracy of the method given by recovery of spiked samples was between 99 and 116%. The HS-SPME method developed was applied to two commercially available bituminous emulsion sealants. External calibration and standard addition approaches were investigated, and statistical paired t-test was performed. The contents of target aromatic hydrocarbons in the sealants studied varied from approximately 0.4 to 150 ppmw. The method developed shows potential as a tool for the determination of aromatic hydrocarbons in emulsified bituminous materials. PMID:17069821

Tang, Bing; Isacsson, Ulf

2006-10-27

339

Applications of electrochemically-modulated liquid chromatography (EMLC): Separations of aromatic amino acids and polycyclic aromatic hydrocarbons  

SciTech Connect

The research in this thesis explores the separation capabilities of a new technique termed electrochemically-modulated liquid chromatography (EMLC). The thesis begins with a general introduction section which provides a literature review of this technique as well as a brief background discussion of the two research projects in each of the next two chapters. The two papers which follow investigate the application of EMLC to the separation of a mixture of aromatic amino acids and of a mixture of polycyclic aromatic hydrocarbons (PAHs). The last section presents general conclusions and summarizes the thesis. References are compiled in the reference section of each chapter. The two papers have been removed for separate processing.

Deng, L.

1998-03-27

340

Aromatic hydrocarbon-degrading bacteria from soil near Scott Base, Antarctica  

Microsoft Academic Search

Hydrocarbons persist in Antarctic soils when fuel oils such as JP8 jet fuel are spilled. For clean-up of hydrocarbon-contaminated\\u000a soils in Antarctica, bioremediation has been proposed using hydrocarbon-degrading microbes indigenous to Antarctic soils.\\u000a A number of alkane-degrading bacteria have been isolated previously from Antarctic soils. In this paper we describe the direct\\u000a isolation of aromatic hydrocarbon-degrading bacteria from oil-contaminated Antarctic

Jackie Aislabie; Julia Foght; David Saul

2000-01-01

341

DNA adducts and carcinogenicity of nitro-polycyclic aromatic hydrocarbons  

SciTech Connect

We have been interested in the structure-activity relationships of nitro-polycyclic aromatic hydrocarbons (nitro-PAHs), and have focused on the correlation of structural and electronic features with biological activities, including mutagenicity and tumorigenicity. In our studies, we have emphasized 1-, 2-, 3-, and 6-nitrobenzo[a]pyrenes (nitro-B[a]Ps) and related compounds, all of which are derived from the potent carcinogen benzo[a]pyrene. While 1-, 2-, and 3-nitro-B[a]P are potent mutagens in Salmonella, 6-nitro-B[a]P is a weak mutagen. In vitro metabolism of 1- and 3-nitro-B[a]P has been found to generate multiple pathways for mutagenic activation. The formation of the corresponding trans-7,8-dihydrodiols and 7,8,9,10-tetrahydrotetrols suggests that 1- and 3-nitro-B[a]P trans-7,8-diol-anti-9, 10--epoxides are ultimate metabolites of the parent nitro-B[a]Ps. We have isolated a DNA adduct from the reaction between 3-nitro-B[a]P trans-7,8-diol-anti-9, 10-epoxide and calf thymus DNA, and identified it as 10-(deoxyguanosin-N{sup 2}-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydro-3-nitro-B[a]P. The same adduct was identified from in vitro metabolism of [{sup 3}H]3-nitro-B[a]P by rat liver microsomes in the presence of calf thymus DNA. A DNA adduct of 3-nitro-B[a]P formed from reaction of N-hydroxy-3-amino-B[a]P, prepared in situ with calf thymus DNA was also isolated. This adduct was identified as 6-(deoxyguanosin-N{sup 2}-yl)-3-amino-B[a]P. The same adduct was obtained from incubating DNA with 3-nitro-B[a]P in the presence of the mammalian nitroreductase, xanthine oxidase, and hypoxanthine. 48 refs., 6 figs., 1 tab.

Fu, P.P.; Herreno-Saenz, D.; Von Tungeln, L.S. [National Center for Toxicological Research, Jefferson, AR (United States)] [and others

1994-10-01

342

Biomarkers in humans exposed to polycyclic aromatic hydrocarbons  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAH) have been identified as a major source of carcinogenic risk in the coke-oven industry. This study evaluates following markers: personal exposure to PAH, DNA adducts, chromosomal aberrations and sister chromatid exchanges (SCE), glutathione S-transferase M1 (GSTM1) and N-acetyltransferase 2 (NAT2) polymorphisms. 23 top side coke-oven workers and 13 unexposed workers employed in the same plant at Kosice, Slovakia were studied. Personal monitors were used to measure carcinogenic PAH exposure during 8 h of working shift prior the collection of blood and urine samples. Personal exposure to eight carcinogenic PAHs ranged from 0.6 to 632 {mu}g/m{sup 3} and from 0.07 to 0.62 {mu}g/m{sup 3} for exposed and control groups, respectively. Based on the values of individual persons, the positive significant correlations were found between DNA adducts detected in WBC and LYM (Spearman r=0.451, p=0.044), between DNA adducts and SCE (r=0.363, p=0.034) and between AB.C. and SCE-H (SCE evaluated as the index of heterogeneity H-variance/mean: r=0.381, p=0.024). Using individual PAH exposure data the following significant correlations between exposure and biomarkers were found: WBC-DNA adducts (r=0.325;p=0.058);SCE-H (r=0.467, p=0.007). Groupwise comparison of the exposed and control groups (Mann-Whitney U-test) showed significantly increased values of SCE (6.71{+-}1.20 vs. 5.20 {+-}1.16, respectively) and DNA adducts in WBC and LYM (2.70{+-}0.74 vs 1.94{+-}0.51 adducts/10{sup 8} nucleotides; 2.46{+-}0.83 vs. 1.60{+-}0.32 adducts/10{sup 8}nucleotides, respectively). No influence of the smoking habits on the biomarkers was detectable in exposed or unexposed individuals. Multifactor analysis of variance taking into account confounding factors such as GSTM1, NAT2, diet and adjusting the data for age and smoking clearly showed the effect of exposure on DNA adducts, AB.C and SCE-H.

Binkova, B.; Topinka, J.; Mrackova, G. [Institute of Hygiene of Central Bohemia and Institute of Experimental Medicine, Prague (Czechoslovakia)] [and others

1997-10-01

343

Aromatic hydrocarbons in the atmospheric environment. Part III: personal monitoring  

NASA Astrophysics Data System (ADS)

As part of a larger study, personal sampling of the aromatic hydrocarbons benzene, toluene, ethylbenzene and the isomeric xylenes (BTEX) was carried out by 55 nonsmoking volunteers for a period of 14 days. Thirty-nine persons lived in a rural area near Hannover (Germany) with hardly any traffic at all, while 16 persons lived in a high-traffic city street in Hannover. The personal exposure level of the persons in the rural area (some commuting to Hannover) was: 2.9, 24.8, 2.4 and 7.7 ?g m -3 for benzene, toluene, ethylbenzene and the sum of xylenes, respectively, while the corresponding data for the high traffic city streets were 4.0, 22.2, 2.8 and 9.7 ?g m -3 (geometric means). Four microenvironments have been monitored which contribute to the total exposure to BTEX, i.e. the home, the outdoor air, the workplace and the car cabin. The most important microenvironment for non-working persons is the private home. The concentration of most BTEX in the private home is almost equal to the personal exposure level, demonstrating that the indoor pollution in the home makes by far the highest contribution to the total exposure. For working people (mostly office workers), the workplace is the second most important microenvironment contributing to the total BTEX exposure. Taking all working persons into consideration (independent of the location of their private home) the personal exposure level is higher by a factor of 1.2-1.4 than that of the workplace (for toluene this factor is 2.2). As already found by others, very high BTEX concentrations may be found in car cabins, in particular, if the engine is gasoline-driven. In the cabin of 44 cars in the rural/urban area average benzene concentrations (geometric mean) of 12/14 ?g m -3 and a maximum value of ˜550 ?g m -3 were found. On average, the participating volunteers drove their car for 45 min day -1 (i.e. 3% of the day). Nevertheless, the car cabin constitutes about 10% of the total benzene exposure. Refueling of the car during the 14-day sampling period has only a small effect on the personal exposure level.

Ilgen, E.; Levsen, K.; Angerer, J.; Schneider, P.; Heinrich, J.; Wichmann, H.-E.

344

Biodegradation aspects of polycyclic aromatic hydrocarbons (PAHs): a review.  

PubMed

PAHs are aromatic hydrocarbons with two or more fused benzene rings with natural as well as anthropogenic sources. They are widely distributed environmental contaminants that have detrimental biological effects, toxicity, mutagenecity and carcinogenicity. Due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity, the PAHs have gathered significant environmental concern. Although PAH may undergo adsorption, volatilization, photolysis, and chemical degradation, microbial degradation is the major degradation process. PAH degradation depends on the environmental conditions, number and type of the microorganisms, nature and chemical structure of the chemical compound being degraded. They are biodegraded/biotransformed into less complex metabolites, and through mineralization into inorganic minerals, H(2)O, CO(2) (aerobic) or CH(4) (anaerobic) and rate of biodegradation depends on pH, temperature, oxygen, microbial population, degree of acclimation, accessibility of nutrients, chemical structure of the compound, cellular transport properties, and chemical partitioning in growth medium. A number of bacterial species are known to degrade PAHs and most of them are isolated from contaminated soil or sediments. Pseudomonas aeruginosa, Pseudomons fluoresens, Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Lignolytic fungi too have the property of PAH degradation. Phanerochaete chrysosporium, Bjerkandera adusta, and Pleurotus ostreatus are the common PAH-degrading fungi. Enzymes involved in the degradation of PAHs are oxygenase, dehydrogenase and lignolytic enzymes. Fungal lignolytic enzymes are lignin peroxidase, laccase, and manganese peroxidase. They are extracellular and catalyze radical formation by oxidation to destabilize bonds in a molecule. The biodegradation of PAHs has been observed under both aerobic and anaerobic conditions and the rate can be enhanced by physical/chemical pretreatment of contaminated soil. Addition of biosurfactant-producing bacteria and light oils can increase the bioavailability of PAHs and metabolic potential of the bacterial community. The supplementation of contaminated soils with compost materials can also enhance biodegradation without long-term accumulation of extractable polar and more available intermediates. Wetlands, too, have found an application in PAH removal from wastewater. The intensive biological activities in such an ecosystem lead to a high rate of autotrophic and heterotrophic processes. Aquatic weeds Typha spp. and Scirpus lacustris have been used in horizontal-vertical macrophyte based wetlands to treat PAHs. An integrated approach of physical, chemical, and biological degradation may be adopted to get synergistically enhanced removal rates and to treat/remediate the contaminated sites in an ecologically favorable process. PMID:19442441

Haritash, A K; Kaushik, C P

2009-04-07

345

Possible molecular targets of halogenated aromatic hydrocarbons in neuronal cells.  

PubMed

Halogenated aromatic hydrocarbon including polychlorinated biphenyls (PCBs) are persistent and bioaccumulative environmental toxicants. Although health effects associated with exposure to these chemicals, including motor dysfunction and impairment in memory and learning, have been identified, their molecular site of action is unknown. Previous study from this laboratory demonstrated that, while ortho PCBs perturbed intracellular signaling mechanisms including Ca2+ homeostasis, receptor-mediated inositol phosphate production and translocation of PKC, non-ortho PCBs did not. Since PKC signaling pathway is implicated in the modulation of motor behavior, as well as learning and memory, and the roles of PKC are isoform-specific, we have now studied the effects of two structurally distinct PCBs on isoforms of PKC in cerebellar granule cell culture model. Cells were exposed to 2,2'-dichlorobiphenyl (ortho PCB; 2,2'-DCB) or 4,4'-dichlorobiphenyl (non-ortho PCB; 4,4'-DCB) for 15 min, respectively, and subsequently fractionated and immunoblotted against the selected PKC monoclonal antibodies (alpha, gamma, delta, epsilon, lambda, iota). While 2,2'-DCB induced a translocation of PKC-alpha [cytosol (% control): 54 +/- 12 at 25 microM and 66 +/- 10 at 50 microM; membrane (% control): 186 +/- 37 at 25 microM and 200 +/- 48 at 50 microM] and -epsilon [cytosol (% control): 92 +/- 12 at 25 microM and 97 +/- 15 at 50 microM; membrane (% control): 143 +/- 23 at 25 microM and 192 +/- 24 at 50 microM] from cytosol to membrane fraction in a concentration-dependent manner, 4,4'-DCB had no effects. 2,2'-DCB induced translocation of PKC-alpha was blocked by pretreatment with sphingosine, suggesting a possible role of sphingolipid pathway. Although reports on implication of PKC-gamma with learning and memory are relatively extensive, the expression of this particular isoform in the primary cerebellar granule cells was below the detectable level. PKC-delta, -lambda and -iota were present in these cells, but were not altered by PCB exposure. These results suggest that the effects of 2,2'-DCB on PKC is isoform-dependent and PKC-alpha as well as PKC-epsilon may be target molecules for ortho-PCBs in neuronal cells. PMID:11162682

Yang, J H; Kodavanti, P R

2001-02-01

346

Equilibrium Moisture Content Equations for some Medicinal and Aromatic Plants  

Microsoft Academic Search

In this research, the most commonly used equilibrium moisture content (EMC) and equilibrium relative humidity (ERH) equations are compared on their ability to best fit the published sorption data for selected medicinal and aromatic plants. A non-linear regression technique is used to fit data subsets. In order to compare the performance of the EMC\\/ERH equations, three statistical error parameters are

Y. Soysal; S. Öztekin

1999-01-01

347

The distribution and sources of polycyclic aromatic hydrocarbons in surface sediments along the Egyptian Mediterranean coast.  

PubMed

Coastal marine sediment samples were collected from 31 sampling stations along the Egyptian Mediterranean Sea coast. All sediment samples were analyzed to determine aliphatic and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC) contents and grain size analysis. Total concentrations of 16 EPA-PAHs in the sediments were varied from 88 to 6338 ng g(-1) with an average value of 154 ng g(-1) (dry weight). However, the concentrations of total aliphatic were varied from 1.3 to 69.9 ng g(-1) with an average value of 15.6 ng g(-1) (dry weight). The highest contents of PAHs were found in the Eastern harbor (6338 ng g(-1)), Manzala (5206 ng g(-1)) and El-Jamil East (4895 ng g(-1)) locations. Good correlations observed between a certain numbers of PAH concentrations allowed to identify its origin. The average total organic carbon (TOC) percent was varied from 0.91 to 4.54%. Higher concentration of total pyrolytic hydrocarbons ( summation operatorCOMB) than total fossil hydrocarbons ( summation operatorPHE) declared that atmospheric fall-out is the significant source of PAHs to marine sediments of the Egyptian Mediterranean coast. The selected marked compounds, a principal component analysis (PCA) and special PAHs compound ratios (phenanthrene/anthracene vs fluoranthene/pyrene; summation operatorCOMB/ summation operatorEPA-PAHs) suggest the pyrogenic origins, especially traffic exhausts, are the dominant sources of PAHs in most locations. Interferences of rather petrogenic and pyrolytic PAH contaminations were noticed in the harbors due to petroleum products deliveries and fuel combustion emissions from the ships staying alongside the quays. PMID:17058015

El Nemr, Ahmed; Said, Tarek O; Khaled, Azza; El-Sikaily, Amany; Abd-Allah, Aly M A

2006-10-21

348

Polycyclic aromatic hydrocarbon emission from straw burning and the influence of combustion parameters  

NASA Astrophysics Data System (ADS)

A simulated burning experiment was conducted in a tubular furnace system to examine the emission of polycyclic aromatic hydrocarbons (PAHs) from the burning of rice and bean straw, and the influence of combustion parameters was investigated. Total emission amounts of 16 PAHs (?PAHs) from the burning of rice and bean straw ranged from 9.29 to 23.6 ?g g -1 and from 3.13 to 49.9 ?g g -1, respectively, which increased with the increase of temperatures from 200 to 700 °C. The contribution of combustion to individual PAH yields was about 80.6-100%, which was generally increased with the increase of burning temperature. Moisture content in straw had a negative effect on PAH formation, especially on PAHs with low molecular weight. ?PAHs emission amounts decreased by 78.2% for bean straw with a moisture content of 30% in comparison with that for dried straw. In addition, PAH emission amounts increased with the increase of O 2 content in supplied air and then decreased, which showed a maximum emission at O 2 content of 40%. The source fingerprint of PAHs in emission from straw burning was established, which showed that naphthalene accounted for 35.0 ± 7.4% of ?PAHs. Based on the experimental data, emission amounts of ?PAHs from the burning of rice and bean straw were estimated to be 320-357 and 32.5-76.0 tons to ambient air per year in China, respectively.

Lu, Hao; Zhu, Lizhong; Zhu, Nali

349

Influence of the bioaccessible fraction of polycyclic aromatic hydrocarbons on the ecotoxicity of historically contaminated soils.  

PubMed

Sequential supercritical fluid extraction together with a two-site desorption model were employed to estimate the bioaccessible fraction of polycyclic aromatic hydrocarbons (PAHs) in four historically contaminated soils. The ecotoxicity of the soils was assayed by four different contact tests. The same soils were exposed to exhaustive extraction and the extracts were returned to the soils to ensure total 100% bioaccessibility of the pollutants. Then the soils were assayed again. Statistical evaluation revealed that the predicted bioaccessible PAHs generally correlated with the ecotoxicity responses of the tests. The estimated bioaccessible fractions varied from 10 to 98%. This value increased for PAHs with higher lipophilicity and showed no correlation with the organic carbon content in the soils. The ecotoxicity tests in the study indicated different sensitivity toward PAHs and the tests employing Heterocypris incongruens and Eisenia fetida were found to be more suitable than Lemna minor and Vibrio fischeri. Mortality and growth inhibition of ostracods correlated with all the types of PAHs and earthworm growth inhibition and mortality were preferentially sensitive to PAHs with only 3-4 aromatic rings. Determination of the biota-soil accumulation factors indicated that the earthworm growth inhibition corresponded to increased accumulation of PAHs in the earthworm tissue. PMID:23611796

?van?arová, Monika; K?esinová, Zdena; Cajthaml, Tomáš

2013-04-02

350

Production of aromatic hydrocarbons through catalytic pyrolysis of 5-Hydroxymethylfurfural from biomass.  

PubMed

Catalytic pyrolysis of 5-Hydroxymethylfurfural (HMF) was conducted on a fixed bed reactor at atmospheric pressure. HMF could be converted into aromatic hydrocarbons through catalytic pyrolysis. The catalysts and reaction conditions were both critical in maximizing the aromatic hydrocarbons selectivity. Four catalysts, ?-zeolite, HZSM-5, Ga/HZSM and In/HZSM were tested in this study. HZSM-5 (Si/Al=50) was found to be the most effective catalyst in both reactivity and selectivity among these catalysts. Under the reaction temperature of 600°C, the highest carbon yield of 48.99% of aromatic hydrocarbons was achieved from catalytic pyrolysis HMF with HZSM-5 (Si/Al=50) as catalyst. Moreover, the HZSM-5 (Si/Al=50) catalyst was recycled for five times without shown deactivation of the catalyst. PMID:23994304

Zhao, Yan; Pan, Tao; Zuo, Yong; Guo, Qing-Xiang; Fu, Yao

2013-07-20

351

Analysis of Atmospheric Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Gas\\/Particle Phases Separately Collected by a High-volume Air Sampler Equipped with a Column Packed with XAD-4 Resin  

Microsoft Academic Search

We developed a sampler for collecting atmospheric polycyclic aromatic hydrocarbons (PAHs) and nitropoly- cyclic aromatic hydrocarbons (NPAHs) by attaching a glass column packed with XAD-4 resin to the gas sampling port of a high-volume air sampler equipped with a filter. When the upper and bottom layers of the column were packed with 64 g and 32 g of XAD-4 resin,

Yuki Araki; Ning Tang; Michihiro Ohno; Takayuki Kameda; Akira Toriba; Kazuichi Hayakawaa

2009-01-01

352

Emissions of polycyclic aromatic hydrocarbons from combustion of agricultural and sylvicultural debris  

NASA Astrophysics Data System (ADS)

In this work, 28 parent and substituted-polycyclic aromatic hydrocarbons (PAHs) have been quantified in 76 smoke samples produced by burning pine wood, pine needles, prickly pear and almond skin using two different kinds of combustion devices. The results show a great variability in the total concentrations of the PAHs, while their proportions in the different samples are practically independent of the type of biomass that is burned. Just a few PAHs with low molecular weight—naphthalene, 1- and 2-methylnaphthalene, acenaphthylene and phenanthrene—are the most common in the different smoke samples, representing between 61% and 72% of the total. The high correlation coefficients between naphthalene and the total concentrations of PAHs, or between naphthalene and the concentrations of PAHs grouped by number of rings, demonstrate that all combustion processes studied are equally affected by the variables that regulate those processes. The results underscore the important role that naphthalene plays in the formation of higher molecular weight PAHs by pyrosynthesis and show that the naphthalene concentration can be used as an indicator of the total hydrocarbons content in the smoke.

Conde, Francisco J.; Ayala, Juan H.; Afonso, Ana M.; González, Venerando

353

Degradation of polycyclic aromatic hydrocarbons with three to seven aromatic rings by higher fungi in sterile and unsterile soils  

Microsoft Academic Search

Seven commercial 3- to 7-ring (R) polycyclic aromatic hydrocarbons (PAH) as well as PAH derived from lignite tar were spiked into 3 soils (0.8 to 9.7% of organic carbon). The disappearance of the original PAH was determined for the freshly spiked soils, for soils incubated for up to 287 d with their indigenous microflora, and for autoclaved, unsterile and pasteurized

Gerhard Gramss; Klaus-Dieter Voigt; Brigitta Kirsche

1999-01-01

354

Polycyclic Aromatic Hydrocarbons from Candiota (South Brazilian) Coal Extracts  

Microsoft Academic Search

The bitumen composition of Candiota coal (south Brazil) was investigated. Coal bitumen was produced by Soxhlet extraction using toluene. Two chromatographic techniques were tested for bitumen fractionation: adsorption liquid chromatography on silica (ALCS) and adsorption liquid chromatography on alumina (ALCA). Results were compared in terms of the quality and quantity of hydrocarbons isolated. Several linear saturated hydrocarbons were found in

Pedro José Sanches Filho; Vera Regina Pereira Nogueira; Laíza Canielas Krause; Maria Regina Alves Rodrigues; Maria do Carmo Ruaro Peralba; Elina Bastos Caramão

2002-01-01

355

Polycyclic aromatic hydrocarbons in Australian coals II. Novel tetracyclic components from Victorian brown coal  

Microsoft Academic Search

Gas chromatographic-mass spectrometric (GC-MS) analysis of a polycyclic aromatic hydrocarbon (PAH) fraction of a Victoria brown coal sample has revealed the presence of a novel series of tetracyclic triterpenoid derived components. The base peak of their mass spectra, at m\\/z 169, suggests an 8, 14-seco (C-ring cleaved) structural configuration with the triterpenoid derived A- and B-rings fully aromatized. Photochemically induced

Alan L. Chaffee; Michael G. Strachan; R. B. Johns

1984-01-01

356

Ancient polycyclic aromatic hydrocarbons in modern soils: 13C, 14C and biomarker evidence  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) of soils from two maize growing fields were analyzed for molecular structure by gas chromatography-mass spectrometry, for 13C\\/12C ratios by isotope ratio mass spectrometry and for 14C age by accelerator mass spectrometry. These investigations indicate that the aromatic fractions are dominated by pyrolytic inputs. Calculation of molecular maturity parameters based on hopanes and PAHs gives values

Éric Lichtfouse; Hélène Budzinski; Philippe Garrigues; Thimothy I. EGLINTON

1997-01-01

357

Polycyclic aromatic hydrocarbons from the co-pyrolysis of catechol and 1,3-butadiene  

Microsoft Academic Search

In order to better understand the reactions responsible for the formation and growth of polycyclic aromatic hydrocarbons (PAH) from solid fuels, we have performed pyrolysis experiments in an isothermal laminar-flow reactor (at temperatures of 600–1000°C and a fixed residence time of 0.3s) with catechol, a model fuel representative of the aromatic moieties in coal and biomass fuels; 1,3-butadiene, a major

Shiju Thomas; Mary J. Wornat

2009-01-01

358

Determination of total and polycyclic aromatic hydrocarbons in aviation jet fuel.  

PubMed

The aviation jet fuel widely used in turbine engine aircraft is manufactured from straight-run kerosene. The combustion quality of jet fuel is largely related to the hydrocarbon composition of the fuel itself; paraffins have better burning properties than aromatic compounds, especially naphthalenes and light polycyclic aromatic hydrocarbons (PAHs), which are characterised as soot and smoke producers. For this reason the burning quality of fuel is generally measured as smoke fermation. This evaluation is carried out with UV spectrophotometric determination of total naphthalene hydrocarbons and a chromatographic analysis to determine the total aromatic compounds. These methods can be considered insufficient to evaluate the human health impact of these compounds due to their inability to measure trace (ppm) amounts of each aromatic hyrcarbon and each PAH in accordance with limitations imposed because of their toxicological properties. In this paper two analytical methods are presented. Both are based on a gas chromatographic technique with a mass detector operating in be selected ion monitoring mode. The first method was able to determine more than 60 aromatic hydrocarbons in a fuel sample in a 35-min chromatographic run, while the second was able to carry out the analysis of more than 30 PAHs in a 40-min chromatographic run. The linearity and sensitivity of the methods in measuring these analytes at trace levels are described. PMID:12580487

Bernabei, M; Reda, R; Galiero, R; Bocchinfuso, G

2003-01-24

359

Polycyclic aromatic hydrocarbons in asteroid 2008 TC3: Dispersion of organic compounds inside asteroids  

NASA Astrophysics Data System (ADS)

Ureilites are carbon-bearing ultramafic rocks characterized by partial melt depletion and a violent disruption resulting in graphitic carbon and diamonds. Among the predominantly polymict ureilite meteorites collected from the impact of asteroid 2008 TC3 on October 7, 2008—the first time an asteroid was spotted in space and subsequently recovered in the form of meteorites—were many fresh-looking chondrites. Four were classified as EH6 (#16), H5 (sample #25), EL6 (#41), and L4 (#A100) chondrites. All are called "Almahata Sitta," named after the nearby inhabited outpost of Station 6. Six hundred meteorites were collected, which show a wide range of densities, textures, reflection properties, and elemental compositions. In this study, we employ laser desorption laser ionization mass spectrometry to analyze the polycyclic aromatic hydrocarbon (PAH) contents of six meteorites from 2008 TC3 that are ureilites (sample #1, #4, #7, #15, #27, and #47) and three anomalous fragments (sample #25, #16, and #41). Numerous organic compounds were detected with a PAH signature that has not been observed in the carbonaceous chondrites previously studied by our experimental apparatus. Specifically, the Almahata Sitta spectra lack the diversity of alkylation series of parent PAHs commonly observed in Murchison and other carbonaceous chondrites. Spatial mappings of aromatic species across the surface of a fragment of sample #4 are presented including detection of what appears to be the aromatic amino acid tyrosine. Potential sources of terrestrial organic contamination are discussed and ruled out as a source of our observations. Meteorites #25 and #16 are found to have the same distribution of PAHs as the Almahata Sitta meteorites. Other chondrites have much different organic fingerprints. We conclude that both an H5 and E chondrite were included in asteroid 2008 TC3 as foreign clasts and that organic compounds contained in ureilites can spread into other parts of an asteroid.

Sabbah, Hassan; Morrow, Amy L.; Jenniskens, Peter; Shaddad, Muawia H.; Zare, Richard N.

2010-10-01

360

Indirect- and direct-acting mutagenicity of diesel, coal and wood burning-derived particulates and contribution of polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons.  

PubMed

Particulates exhausted from two types of diesel engines (DEPs), burning-derived particulates from three types of coal (CBPs) and burning-derived particulates from three types of wood (WBPs) were separated into four fractions by silica-gel column chromatography using n-hexane, n-hexane-dichloromethane (3:1, v/v), dichloromethane and methanol, as the corresponding eluents. The indirect-acting mutagenicity of each fraction was assayed by the Ames test using the Salmonella typhimurium TA100 strain with S9 mix and the direct-acting mutagenicity was assayed using the S. typhimurium TA98 strain without S9 mix. The polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) of each fraction were determined by high-performance liquid chromatography (HPLC). Both direct- and indirect-acting of mutagenicities were the highest in samples of DEPs. The contributions of PAHs in samples of WBPs and NPAHs in DEPs were the largest, respectively. PMID:19896557

Yang, Xiao-Yang; Igarashi, Kazuhiko; Tang, Ning; Lin, Jin-Ming; Wang, Wei; Kameda, Takayuki; Toriba, Akira; Hayakawa, Kazuichi

2009-11-05

361

Remediation of polycyclic aromatic hydrocarbons. (Latest citations from Pollution abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the removal of polycyclic aromatic hydrocarbons from contaminated soil or water. The chemical or biological processes that destroy these contaminants or reduce their toxicity are discussed. Techniques include treatments used in above-ground reactors or in situ detoxification of contaminated sites. The citations examine the relationship between the chemical structure of polycyclic aromatic hydrocarbons and rate of decomposition; selection of the most effective microorganisms for biological degradation; and factors which can accelerate or inhibit degradation.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1997-12-01

362

Polycyclic aromatic hydrocarbons profiles of spent drilling fluids deposited at Emu-Uno, Delta State, Nigeria.  

PubMed

The concentrations and profiles of polycyclic aromatic hydrocarbons were determined in spent drilling fluid deposited at Emu-Uno, Delta State of Nigeria. The total concentrations of polycyclic aromatic hydrocarbons in the spent drilling fluid deposits ranged between 40 and 770 ?g kg(-1). The PAHs profile were predominantly 2- and 3-rings with acenaphthalene, phenanthrene, fluorene being the predominant PAHs. The prevalence of 2- and 3-rings PAHs in the spent drilling fluid deposits indicate contamination of the drilling fluids with crude oil during drilling. Incorporation of spent drilling fluids into the soil has serious implication for soil, surface water and groundwater quality. PMID:21809098

Iwegbue, Chukwujindu M A

2011-08-02

363

Analytical and chromatographic methods for the determination of cyano polycyclic aromatic hydrocarbons in coal-derived materials. [Cyano polycyclic aromatic hydrocarbons  

Microsoft Academic Search

An adsorption chromatographic method has been described for the isolation of cyano-polycyclic aromatic hydrocarbons (PAH) from the PAH and other N-PAC species found in complex matrices. The utility of these methods has been demonstrated by the separation and detailed characterization of the cyano-PAH in a carbon black extract and a coal-derived gasifier medium oil. Results from microbial mutagenicity and aquatic

D. W. Later; S. A. Barraclough; R. B. Lucke; R. A. Pelroy; P. Stoker; G. M. Booth

1984-01-01

364

Hydrocarbon Content of Geopressured Brines. Final Report.  

National Technical Information Service (NTIS)

Design Well data (bottomhole pressure minus wellhead pressure, GWR, and hydrocarbon composition) is presented as a function of producing conditions. These are examined in conjunction with the following models to attempt to deduce the reservoir brine satur...

T. L. Osif

1985-01-01

365

BN-Dibenzo[a,o]picenes: Analogues of an Unknown Polycyclic Aromatic Hydrocarbon.  

PubMed

Reflecting on synthetic pinnacles: Whereas the parent hydrocarbon is not readily accessible, several examples of BN substituted-dibenzo[a,o]picenes can be prepared in two steps from known starting materials. These non-linear heptacene analogues are water-stable materials. Their preparation utilizes a potentially general method for preparing extended BN analogues of difficult-to-synthesize polycyclic aromatic hydrocarbon frameworks. PMID:23897598

Neue, Benedikt; Araneda, Juan F; Piers, Warren E; Parvez, Masood

2013-07-29

366

Sample extraction and purification for determination of polycyclic aromatic hydrocarbons by reversed-phase chromatography  

SciTech Connect

Hydrocarbons are extracted from samples by alkaline digestion, and interfering materials are removed by adsorption onto Florisil, partitioning of the sample between isooctane and dimethyl sulfoxide, and column chromatography on Sephadex LH-20. A radioactive internal standard is used to correct for losses during procedures. Twenty polycyclic aromatic hydrocarbons are determined by reversed-phase high-pressure liquid chromatography, utilizing simultaneous detection by untraviolet absorbance and fluorescence monitors. 2 figures.

Dunn, B.P.; Armour, R.J.

1980-11-01

367

Sample extraction and purification for determination of polycyclic aromatic hydrocarbons by reversed-phase chromatography  

Microsoft Academic Search

Hydrocarbons are extracted from samples by alkaline digestion, and interfering materials are removed by adsorption onto Florisil, partitioning of the sample between isooctane and dimethyl sulfoxide, and column chromatography on Sephadex LH-20. A radioactive internal standard is used to correct for losses during procedures. Twenty polycyclic aromatic hydrocarbons are determined by reversed-phase high-pressure liquid chromatography, utilizing simultaneous detection by untraviolet

Bruce P. Dunn; Robert J. Armour

1980-01-01

368

Accumulation of polycyclic aromatic hydrocarbons by Neocalanus copepods in Port Valdez, Alaska  

Microsoft Academic Search

Sampling zooplankton is a useful strategy for observing trace hydrocarbon concentrations in water because samples represent an integrated average over a considerable effective sampling volume and are more representative of the sampled environment than discretely collected water samples. We demonstrate this method in Port Valdez, Alaska, an approximately 100km2 basin that receives about 0.5–2.4kg of polynuclear aromatic hydrocarbons (PAH) per

Mark G. Carls; Jeffrey W. Short; James Payne

2006-01-01

369

Geochemistry of polycyclic aromatic hydrocarbons in the bottom sediments of the eastern Arctic shelf  

Microsoft Academic Search

Sources and pathways of supply of polycyclic aromatic hydrocarbons (PAH) in the surface sediments of the Laptev and East Siberian\\u000a seas were identified based on an analysis of the lithological-geochemical characteristics and distribution of organic matter\\u000a (OM). The distribution of organic carbon, humic acids, bitumoids, and hydrocarbons demonstrates the determining role of the\\u000a riverine runoff in the formation of the

V. I. Petrova; G. I. Batova; A. V. Kursheva; I. V. Litvinenko; V. M. Savinov; T. N. Savinova

2008-01-01

370

Aliphatic and polycyclic aromatic hydrocarbons in surface sediments from Elefsis Bay, Greece (Eastern Mediterranean)  

Microsoft Academic Search

Surface sediments were collected from Elefsis Bay (Greece), an area receiving important industrial and domestic pollution, between 1994 and 1995. The sediments were analyzed for composition of aliphatic hydrocarbons (AHC) and polycylic aromatic hydrocarbons (PAH) by GC\\/MS. AHC concentrations over all sampling periods and stations ranged from 85.7 to 1062 ?g\\/g dry sediment, while PAH concentrations ranged from 481 to

E. Sklivagou; S. P. Varnavas; J. Hatzianestis

2001-01-01

371

Isomerization and aromatization of hydrocarbons and the paleothermometry and burial history of Alberta Foreland Basin  

Microsoft Academic Search

The hydrocarbon fractions extracted from 34 Cretaceous shales from a cross section of the Alberta basin have been analyzed using gas chromatography-mass spectrometry. Particular attention has been paid to the extents to which three temperature-dependent geochemical reactions have occurred: isomerization of steranes at C-20; isomerization of hopanes at C-22; and aromatization of C-ring monoaromatic steroid hydrocarbons. Estimates of the kinetic

C. Beaumont; R. Boutillier; A. S. Mackenzie; J. Rullkotter

1985-01-01

372

Estrogenic activity of environmental polycyclic aromatic hydrocarbons in uterus of immature Wistar rats  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are an important group of environmental pollutants, known for their mutagenic and carcinogenic activities. Many PAHs are aryl hydrocarbon receptor (AhR) ligands and several recent studies have suggested that PAHs or their metabolites may activate estrogen receptors (ER). The present study investigated possible estrogenic\\/antiestrogenic effects of abundant environmental contaminants benzo[a]pyrene (BaP), benz[a]anthracene (BaA), fluoranthene (Fla) and

Vladimír Kummer; Jarmila Mašková; Zden?k Zralý; Ji?í Ne?a; Pavlína Šime?ková; Jan Vondrá?ek; Miroslav Machala

2008-01-01

373

Biosurfactant production by a soil Pseudomonas strain growing on polycyclic aromatic hydrocarbons  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants occurring mostly as a result of fossil fuel combustion and as by-products of industrial activities. The bioremediation of soils contaminated with PAHs is limited by the poor availability of dyrophobic contaminants to microorganisms. Surfactants can help. Recent studies indicate that addition of surfactants can enhance hydrocarbon biodegradation. This study examines whether production of surfactants by PAH-metabolizing microorganisms is part of their strategy for growing on such poorly available substrates.

Deziel, E.; Paquette, G.; Villemur, R.; Lepine, F. [Univ. du Quebec, Laval (Canada)] [and others

1996-06-01

374

High-resolution electron spectroscopy, preferential metal-binding sites, and thermochemistry of lithium complexes of polycyclic aromatic hydrocarbons  

NASA Astrophysics Data System (ADS)

Polycyclic aromatic hydrocarbons are model systems for studying the mechanisms of lithium storage in carbonaceous materials. In this work, Li complexes of naphthalene, pyrene, perylene, and coronene were synthesized in a supersonic metal-cluster beam source and studied by zero-electron-kinetic-energy (ZEKE) electron spectroscopy and density functional theory calculations. The adiabatic ionization energies of the neutral complexes and frequencies of up to nine vibrational modes in the singly charged cations were determined from the ZEKE spectra. The metal-ligand bond energies of the neutral complexes were obtained from a thermodynamic cycle. Preferred Li/Li+ binding sites with the aromatic molecules were determined by comparing the measured spectra with theoretical calculations. Li and Li+ prefer the ring-over binding to the benzene ring with a higher ?-electron content and aromaticity. Although the ionization energies of the Li complexes show no clear correlation with the size of the aromatic molecules, the metal-ligand bond energies increase with the extension of the ?-electron network up to perylene, then decrease from perylene to coronene. The trends in the ionization and metal-ligand bond dissociation energies of the complexes are discussed in terms of the orbital energies, local quadrupole moments, and polarizabilities of the free ligands and the charge transfer between the metal atom and aromatic molecules.

Lee, Jung Sup; Krasnokutski, Serge A.; Yang, Dong-Sheng

2011-01-01

375

First evidence of Dinophysistoxin-1 ester and carcinogenic polycyclic aromatic hydrocarbons in smoked bivalves collected in the Patagonia fjords.  

PubMed

Diarrhetic shellfish poisoning (DSP) is a gastrointestinal disease caused by fat-soluble polyether toxins produced by dinoflagellates and accumulated in shellfish. Up to the present, only four fat-soluble polyethers have been known as diarrhetic shellfish toxins. Among them,*** Okadaic acid, Dinophysistoxin-1, Dinophysistoxin-2 and Dinophysistoxin-3. Outbreaks associated with DSP have occurred in the Chilean Patagonia fjords since 1970. Native people, who live in small communities close to the southern fjords, smoke fresh shellfish. During this popular smoking procedure, they impregnate the shellfish with polycyclic aromatic hydrocarbons, as incomplete combustion products, which are potent carcinogenic compounds, this product is sold in local markets without phycotoxins analysis or inclusion in any monitoring program. The present paper shows, DSP phycotoxins quantitation, using high performance liquid chromatography with fluorescent and mass spectrometric detection and the measurements of polycyclic aromatic hydrocarbons by gas chromatography with mass detection, in smoked shellfish samples. The presence of Dinophysistoxin-3, the Dinophysistoxin-1 ester (7-O-acyl-derivatives of dinophysistoxin-1), was assessed in all shellfish samples analyzed. The 7-OH in Dinophysistoxin-1 was esterified with palmitic fatty acid. The shellfish meat contains seven polycyclic aromatic hydrocarbons, among them fluoranthene, phenanthrene, anthracene, pyrene and benzo[a]pyrene. The gas chromatography-mass spectrometry analysis showed four of the six most frequent carcinogenic polycyclic aromatic hydrocarbons reported. The content of benzo[a]pyrene in the Razor Clam and Ribbed Mussel were 78.61 and 4.94 ng/g of shellfish dry weight, respectively. In both cases the benzo[a]pyrene amounts were greater than the acceptable tolerance limits of 1 microg/kg of sample. The Razor Clam samples also show amount further above the maximum label regulated by FAO/WHO (10 microg/kg). The presence of both type of compounds in the smoked shellfish samples analyzed, correspond to a dangerous combination, where the polycyclic aromatic hydrocarbons are carcinogenic compounds by themselves and DTX-1, is a potent tumor promoter. PMID:15019471

García, Carlos; González, Viviana; Cornejo, Carlos; Palma-Fleming, Hernán; Lagos, Néstor

2004-02-01

376

Effect of condensed organic matter on solvent extraction and aqueous leaching of polycyclic aromatic hydrocarbons in soils and sediments.  

PubMed

The contents of nonhydrolyzable organic matter (NHC) and black carbon (BC) were measured in soils and sediments from the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons (PAHs) were extracted respectively by Soxhlet and an accelerated solvent extraction device (ASE) using different solvents. In addition, sequential aqueous leaching at different temperatures was carried out. The PAH content extracted with the sequential three solvent ASE is two times higher than that using the Soxhlet extraction method. The relationship of the PAH content with the NHC content is very significant. The PAH concentrations measured at various temperature steps fit well to the Van't Hoff equation and the enthalpy was estimated. The investigation indicates that condensed organic matter such as kerogen carbon, aged organic matter, and BC is relevant for the extraction and distribution of native PAHs in the investigated field soils and sediments. PMID:17257721

Ran, Yong; Sun, Ke; Ma, Xiaoxuan; Wang, Guohui; Grathwohl, Peter; Zeng, Eddy Y

2007-01-24

377

Enumeration and characterization of the soil microflora from hydrocarbon-contaminated soil sites able to mineralize polycyclic aromatic hydrocarbons (PAH)  

Microsoft Academic Search

The use of a plate screening technique allowed the direct isolation and quantification of polycylic aromatic hydrocarbon (PAH)-degrading bacteria from different soil sites. Bacteria that were able to grow on anthracene, phenanthrene, fluoranthene or pyrene as a sole carbon source were found with numbers between 103 and 105 colony-forming units (cfu)\\/g of soil dry weight, but only in samples that

M. Kästner; M. Breuer-Jammali; B. Mahro

1994-01-01

378

The 1994 QUASIMEME Laboratory-Performance Studies: Polycyclic aromatic hydrocarbons (PAH) in standard solutions  

Microsoft Academic Search

A Laboratory Performance Study has been undertaken in order to assess and improve the measurement of concentrations of polycyclic aromatic hydrocarbons in standard solutions as part of the QUASIMEME (EU-Measurement and Testing) Project. Thirty-six laboratories were invited to participate and, of these, 25 returned data on 10 individual parent PAH compounds in two acetonitrile solutions. Techniques based upon both gas

Robin J Law; Jarle Klungsøyr

1996-01-01

379

Parking lot sealcoat: an unrecognized source of urban polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous contaminant in urban environments. Although numerous sources of PAHs to urban runoff have been identified, their relative importance remains uncertain. The authors show that a previously unidentified source of urban PAHs, parking lot sealcoat, may dominate loading of PAHs to urban water bodies in the United States. Particles in runoff from parking lots

Barbara J. Mahler; Peter C. Van Metre; Thomas J. Bashara; Jennifer T. Wilson; David A. Johns

2005-01-01

380

Toxicity of aromatic polycyclic hydrocarbons. (Latest citations from the Life Sciences Collection database). Published Search  

SciTech Connect

The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Topics include effects on metabolism and liver activity, cellular responses, binding characteristics, and the occurrence and path of the compounds in food chains. Bioaccumulation studies in specific areas, and isolation and detection techniques are also considered. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1993-11-01

381

Toxicity of aromatic polycyclic hydrocarbons. (Latest citations from the Life Sciences Collection data base). Published Search  

SciTech Connect

The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Topics include effects on metabolism and liver activity, cellular responses, binding characteristics, and the occurrence and path of the compounds in food chains. Bioaccumulation studies in specific areas, and isolation and detection techniques are also considered. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1992-05-01

382

Toxicity of aromatic polycyclic hydrocarbons. (Latest citations from the Life Sciences Collection database). Published Search  

SciTech Connect

The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Topics include effects on metabolism and liver activity, cellular responses, binding characteristics, and the occurrence and path of the compounds in food chains. Bioaccumulation studies in specific areas, and isolation and detection techniques are also considered. (Contains 250 citations and includes a subject term index and title list.)

Not Available

1994-11-01

383

Cytotoxicity in human skin fibroblasts induced by photoactivated polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAH) require chemical modification in order to exert their mutagenic\\/carcinogenic activity on biological systems. The mode of activation which has been most extensively studied involves enzyme-catalyzed oxidation reactions but PAH can also be modified into oxidized and radical intermediates upon exposure to various radiations. The resulting products have been shown to be cytotoxic, mutagenic and carcinogenic in

G. F. Strniste; R. J. Brake

1980-01-01

384

Fluorescence, Absorption, and Excitation Spectra of Polycyclic Aromatic Hydrocarbons as a Tool for Quantitative Analysis  

ERIC Educational Resources Information Center

|A quantitative and qualitative study of the interplay between absorption, fluorescence, and excitation spectra of pollutants called polycyclic aromatic hydrocarbons (PAHs) is conducted. The study of five PAH displays the correlation of the above-mentioned properties along with the associated molecular changes.|

Rivera-Figueroa, A. M.; Ramazan, K. A.; Finlayson-Pitts, B. J.

2004-01-01

385

CONCENTRATIONS AND PHASE DISTRIBUTIONS OF NITRATED AND OXYGENATED POLYCYCLIC AROMATIC HYDROCARBONS IN AMBIENT AIR  

EPA Science Inventory

The concentrations of nitrated and oxygenated aromatic hydrocarbons (PAH) in ambient air, both in the vapor phase and adsorbed on airborne particles, were measured over a 12-month period in Houston, Texas. easonal variations in the levels of the target compounds were weakly relat...

386

Increased retention of polycyclic aromatic hydrocarbons in soils induced by soil treatment with humic substances  

Microsoft Academic Search

The analytical recovery of a mixture of polycyclic aromatic hydrocarbons (PAHs) was determined from a soil before and after oxidation with hydrogen peroxide, and subsequently treated with increasing amounts of an exogenous humic acid and subjected to different incubation periods. The release of PAHs from soil depended on the specific structure and physico-chemical properties of each PAH, and increased with

P. Conte; A. Zena; G. Pilidis; A. Piccolo

2001-01-01

387

Atmospheric polycyclic aromatic hydrocarbons in North China: a winter-time study  

Microsoft Academic Search

The contamination and outflow of atmospheric polycyclic aromatic hydrocarbons (PAHs) in the Chinese Northern Plain, a region with a total area of 300 000 km² and a high PAH emission density, were investigated. Polyurethane foam (PUF) and PM10 samples were collected at 46 sites located in urban, rural (towns or villages), and control (remote mountain) areas in the winter from

Shuzhen Liu; Shu Tao; Wenxin Liu; Yanan Liu; Han Dou; Jingyu Zhao; Luguang Wang; Jingfei Wang; Zaifeng Tian; Yuan Gao

2007-01-01

388

Fate of polycyclic aromatic hydrocarbons during composting of activated sewage sludge with green waste  

Microsoft Academic Search

The level and fate of 16 polycyclic aromatic hydrocarbons (PAHs), targeted by the US Environmental Protection Agency (USEPA), has been studied over 90 days of composting of activated sludge with green waste, under a semi-arid climate. The total PAH calculated from the sum of the amounts of the 16 PAHs in the initial mixture of activated sludge and green waste,

M. Hafidi; S. Amir; A. Jouraiphy; P. Winterton; M. El Gharous; G. Merlina; J.-C. Revel

2008-01-01

389

Removal of polycyclic aromatic hydrocarbons by low density polyethylene from liquid model and roasted meat  

Microsoft Academic Search

Low density polyethylene (LDPE) was used to remove polycyclic aromatic hydrocarbons (PAHs) from liquid media and roasted meat by sorption. Three liquid models and five carcinogenic PAHs were employed to monitor the sorption process, and amounts of chemicals were determined by GC-FID. More than 50% of the total adsorption occurred within 24 h for the selected PAHs in the three

Jason Chen; Shaun Chen

2005-01-01

390

Modeling of nitro-polycyclic aromatic hydrocarbon formation and decay in the atmosphere  

Microsoft Academic Search

A reaction mechanism of polycyclic aromatic hydrocarbons (PAH) and nitro-PAH (NPAH) in the gas and particle phase in the atmosphere has been further evaluated and modified using outdoor smog chamber experimental results. Diesel exhaust emissions were added to a 190 m3 outdoor smog chamber and permitted to age under conditions of daylight and darkness. A sampling train consisting of an

Zhihua Fan; Danhua Chen; Parag Birla; Richard M. Kamens

1995-01-01

391

Annual rates of deposition of polycyclic aromatic hydrocarbons in different forest ecosystems  

Microsoft Academic Search

Using the flux balance of the forest canopy of a beech and a spruce stand annual rates of total deposition — divided into precipitation and interception deposition — were derived for 4 polycyclic aromatic hydrocarbons (PAH). The deposition of PAH is in general higher under spruce because of higher rates of interception deposition as compared to beech. The rate of

F. Matzner

1984-01-01

392

Gas\\/particle partitioning of seven volatile polycyclic aromatic hydrocarbons in a heavy traffic urban area  

Microsoft Academic Search

Air samples (vapor- and particle-phase) were taken for 19 sampling events during the period from December 1997 to July 1998 in an urban site in the center of Athens. The urban site is densely populated and characterized by heavy traffic circulation and elevated concentrations of VOCs, NOx, CO and smoke. Seven volatile polycyclic aromatic hydrocarbons (PAHs) were determined in samples.

Ioannis E. Sitaras; Evangelos B. Bakeas; Panayotis A. Siskos

2004-01-01

393

Relationships between molecular and physicochemical properties of polycyclic aromatic hydrocarbons and adsorptive behavior in aqueous systems  

Microsoft Academic Search

Thirteen of the sixteen polycyclic aromatic hydrocarbons (PAH) which appear on the US Environmental Protection Agency priority pollutant list have been investigated with respect to liquid phase\\/suspended solid phase partitioning in coal refinery effluents and with respect to adsorption onto activated carbon. Partitioning and adsorption characteristics were examined in terms of PAH molecular and physicochemical properties. The liquid and suspended

1981-01-01

394

Source Identification of Polycyclic Aromatic Hydrocarbons by Diagnostic Ratios and Positive Matrix Factorization  

Microsoft Academic Search

Although polycyclic aromatic hydrocarbons (PAHs) are also of natural origin, in many regions their environmental concentrations have strongly increased due to human activities. These semivolatile organic compounds are generally formed during incomplete combustion. Other sources include volatilization from unburned petroleum or tire abrasion in road traffic. Among all pollutants PAHs pose the highest human health hazard in Europe (WHO, 2003).

A. Dvorska; J. Jarkovsky; G. Lammel; J. Klanova

2009-01-01

395

Sorption of selected polycyclic aromatic hydrocarbons on soils in oil-contaminated systems  

Microsoft Academic Search

The adsorption and desorption behaviour of selected polycyclic aromatic hydrocarbons (PAHs) on different soils was investigated by static and dynamic methods. On the basis of a system including the four phases of soil, water, oil adsorbed and oil in emulsion, a model for the description of the adsorption behaviour in the presence of oil was developed. In systems without oil

T Walter; H. J Ederer; C Först; L Stieglitz

2000-01-01

396

Adsorption of polycyclic aromatic hydrocarbons (PAHs) by soil particles: influence on biodegradability and biotoxicity  

Microsoft Academic Search

Polycyclic aromatic hydrocarbon (PAH) biodegradation was investigated in contaminated soils from two different industrial sites under simulated land treatment conditions. Soil samples from a former impregnation plant (soil A) showed high degradation rates of PAHs by the autochthonous microorganisms, whereas PAHs in material of a closed-down coking plant (soil B) were not degraded even after inoculation with bacteria known to

Walter D. Weissenfels; Hans-Jiirgen Klewer; Joseph Langhoff

1992-01-01

397

Removal of surfactant solubilized polycyclic aromatic hydrocarbons by Phanerochaete chrysosporium in a rotating biological contactor reactor  

Microsoft Academic Search

White rot fungi can oxidize surfactant solubilized polycyclic aromatic hydrocarbons (PAH). The objective of this study was to evaluate the performance of immobilized white rot fungus, Phanerochaete chrysosporium, to remove surfactant Tween 80 solubilized PAH i.e. phenanthrene, pyrene and benzo(?)pyrene in a rotating biological contactor (RBC) reactor. Results indicated that the immobilized P. chrysosporium in the RBC reactor system in

Zhongming Zheng; Jeffrey Philip Obbard

2002-01-01

398

Removal of polycyclic aromatic hydrocarbons from water by migration into polyethylene  

Microsoft Academic Search

Water was spiked with three polycyclic aromatic hydrocarbons (PAHs) and filled into a steel diffusion chamber. Low-density polyethylene sheet combined of five polyethylene foils was used as a partition in the chamber. Depth of PAHs migration into the sheet was followed for 143 h, using high performance liquid chromatography with selective fluorimetric detection after extraction of PAHs from the foils

P. Šimko; P. Šimon; V. Khunova

1999-01-01

399

ADSORPTION AND RECOVERY OF NITRATED POLYCYCLIC AROMATIC HYDROCARBONS ON HYBRID SURFACTANT EXPANDED ZIRCONIUM-PHOSPHATE  

Microsoft Academic Search

This paper focuses on the removal of nitro substituted polycyclic aromatic hydrocarbon compounds (NPAHs) from water using low cost synthesized zirconium phosphate mesoporous materials. These materials are lamellar type incorporating n-alkyl-(n = 12 and n = 16) trimethylamonium bromide molecules with different concentrations. For comparison of their performance as adsorbents and in the recovery of NPAH, their results were compared

M. Algarra; M. V. Jiménez; F. G. Sánchez; J. Soto; J. J. Jiménez; Joaquim C. G. Esteves da Silva

2009-01-01

400

The importance of snow scavenging of polychlorinated biphenyl and polycyclic aromatic hydrocarbon vapors  

Microsoft Academic Search

Recently, experimental data on the scavenging of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from the atmosphere by snow were interpreted assuming that the distribution of chemical between particles and dissolved phase measured in the meltwater reflects the state of the chemical during the scavenging process. A consequence of this assumption is that vapor scavenging is found to be

Frank Wania; Donald Mackay; John T. Hoff

1999-01-01

401

Multispecies and Monoculture Rhizoremediation of Polycyclic Aromatic Hydrocarbons (PAHs) from the Soil  

Microsoft Academic Search

In this study, we investigated the potential of multispecies rhizoremediation and monoculture rhizoremediation in decontaminating polycyclic aromatic hydrocarbon (PAH) contaminated soil. Plant-mediated PAH dissipation was evaluated using monoplanted soil microcosms and soil microcosms vegetated with several different grass species (Brachiaria serrata and Eleusine corocana). The dissipation of naphthalene and fluorene was higher in the “multispecies” vegetated soil compared to the

Mphekgo P. Maila; P. Randima; Thomas E. Cloete

2005-01-01

402

Simulating the effect of carbon nanotube curvature on adsorption of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

The results of Molecular Dynamics simulation of polycyclic aromatic hydrocarbons adsorption on single-walled (13,9) carbon\\u000a nanotube are reported. We discuss the angular orientation and plausible adsorbed states of molecules. It is shown, that suggested\\u000a by Gotovac et al. orientation of adsorbed molecules is correct.

Rados?aw P. Weso?owski; Sylwester Furmaniak; Artur P. Terzyk; Piotr A. Gauden

2011-01-01

403

Prediction of retention indices of polynuclear aromatic hydrocarbons. Part II. Capillary gas chromatography  

SciTech Connect

A trigonal additivity procedure has been examined and found to correlate well with retention indices for polynuclear aromatic hydrocarbons on several gas chromatographic stationary phases. The results of this analysis are compared to those obtained using the better known Randic (Connectivity) index.

Ho, C.N.; Kennedy, J.R.; Samyajulu, G.R.; Karlesky, D.; Warner, I.M.

1984-01-01

404

QSAR ESTIMATED OF EXCITED STATES AND PHOTOINDUCED ACUTE TOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS  

EPA Science Inventory

Direct calculation of the energy of excited states for polycyclic aromatic hydrocarbons using semi-empirical methods on a supercomputer were inadequate in explaining spectroscopic data or measured phytotoxicity. he energy difference between frontier orbitals HOMO-LUMO gap of "ave...

405

Occurrence and Phylogenetic Diversity of Sphingomonas Strains in Soils Contaminated with Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Bacterial strains of the genus Sphingomonas are often isolated from contaminated soils for their ability to use polycyclic aromatic hydrocarbons (PAH) as the sole source of carbon and energy. The direct detection of Sphingomonas strains in contaminated soils, either indigenous or inoculated, is, as such, of interest for bioremediation purposes. In this study, a culture-independent PCR-based detection method using specific

Natalie M. E. J. Leys; Annemie Ryngaert; Leen Bastiaens; Willy Verstraete; Eva M. Top; Dirk Springael

2004-01-01

406

Risk of polycyclic aromatic hydrocarbon (PAH) exposure from ingested food: The Azerbaijan case study  

Microsoft Academic Search

Risks due to polycyclic aromatic hydrocarbons (PAHs) exposure from food consumption for the population of Azerbaijan were determined using deterministic and probabilistic methods. The guidelines and methods described and presented in the United States Environmental Protection Agency (U.S. EPA) Risk Assessment Guidance for Superfund (RAGS) Part A was used in performing the risk assessments. The current study utilized concentration data

Oke C. Nwaneshiudu; Robin L. Autenrieth; Thomas J. McDonald; Kirby C. Donnelly; Erica D. Degollado; Afraa A. Abusalih

2007-01-01

407

Role of nutrients in the utilization of polycyclic aromatic hydrocarbons by halotolerant bacterial strain  

Microsoft Academic Search

A halotolerant bacterial strain VA1 isolated from marine environment was studied for its ability to utilize polycylic aromatic hydrocarbons (PAHs) under saline condition. Anthracene and pyrene were used as representatives for the utilization of PAH by the bacterial strain. Glucose and sodium citrate were used as additional carbon sources to enhance the PAH utilization. The strain VA1 was able to

Pugazhendi Arulazhagan; Namsivayam Vasudevan

2011-01-01

408

Proxy Methods and Compounds for Workplace Monitoring of Polynuclear Aromatic Hydrocarbons.  

National Technical Information Service (NTIS)

A proxy compound of polycyclic aromatic hydrocarbons (PAH) is a measurable compound that represents a very large complex group of PAH compounds that are found in nearly all real life samples. In studies of biological impact, the proxy should be the limiti...

R. B. Gammage A. Bjorseth

1979-01-01

409

Phototoxic response of Lumbriculus variegatus to sediments contaminated by polycyclic aromatic hydrocarbons  

Microsoft Academic Search

The toxicity of certain polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms can be greatly increased upon exposure of the organisms to ultraviolet (UV) radiation present in sunlight. The phenomenon of photoactivation of PAHs had received some attention in the laboratory; however, evaluation of the photoinduced toxicity of PAHs in field settings has been limited. In these studies, in situ chambers

Philip D. Monson; Gerald T. Ankley; Patricia A. Kosian

1995-01-01

410

Additive Toxicity of Binary Mixtures of Phototoxic Polycyclic Aromatic Hydrocarbons to the Oligochaete Lumbriculus variegatus  

Microsoft Academic Search

Toxicity of some polycyclic aromatic hydrocarbons (PAHs) can increase by an order of magnitude, or more, in the presence of solar ultraviolet (UV) radiation. In the environment, PAHs exist as complex mixtures, which generally would include multiple PAHs that could cause photoinduced toxicity. Hence, to accurately predict the potential ecological risk of phototoxic PAHs, it is critical to understand their

Russell J. Erickson; Gerald T. Ankley; David L. DeFoe; Patricia A. Kosian; Elizabeth A. Makynen

1999-01-01

411

Diversity of ndo Genes in Mangrove Sediments Exposed to Different Sources of Polycyclic Aromatic Hydrocarbon Pollution  

Microsoft Academic Search

Polycyclic aromatic hydrocarbon (PAH) pollutants originating from oil spills and wood and fuel combustion are pollutants which are among the major threats to mangrove ecosystems. In this study, the composition and relative abundance in the sediment bacterial communities of naphthalene dioxygenase (ndo) genes which are important for bacterial adaptation to environmental PAH contamination were investigated. Three urban mangrove sites which

Newton C. Marcial Gomes; Ludmila R. Borges; Rodolfo Paranhos; Fernando N. Pinto; Ellen Krogerrecklenfort; Leda C. S. Mendonca-Hagler; Kornelia Smalla

2007-01-01

412

Polycyclic aromatic hydrocarbons in water and sediment of the Baltic Sea  

Microsoft Academic Search

Between 1992 and 1994, the distribution of 15 polycyclic aromatic hydrocarbons (PAHs) was investigated in seawater and surface sediments of the Baltic Sea. The analysis of PAHs in seawater is very difficult due to the low concentration. High separation capability is required. A method for analysing very low concentrations of PAHs is presented. The method is based on the high-performance

G. Witt

1995-01-01

413

Sediment-porewater partition of polycyclic aromatic hydrocarbons (PAHs) from Lanzhou Reach of Yellow River, China  

Microsoft Academic Search

Pollution of polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment has drawn much attention around the world. The occurrence of 16 priority PAHs in the sediments and corresponding porewaters in Lanzhou Reach of Yellow River, China, and their partitioning behavior between the two phases were investigated. The results demonstrated that the total PAH levels in the sediments were positively correlated

Yong Yu; Jian Xu; Ping Wang; Hongwen Sun; Shugui Dai

2009-01-01

414

Distribution of Petroleum and Aromatic Hydrocarbons at a Former Crude Oil and Natural Gas Production Facility  

Microsoft Academic Search

Site characterization and remediation activities were performed at a former crude oil and natural gas production facility prior to redevelopment of the site. Field activities included delineation, excavation and segregation of approximately 1,250,000 m of soil impacted by total petroleum hydrocarbons (TPH) and the aromatic volatile organic compounds (VOCs) benzene, toluene, ethylbenzene, and xylenes (hereafter, collectively referred to as BTEX).

D. A. Soukup; A. L. Ulery; Steve Jones

2007-01-01

415

Minimal clean-up and rapid determination of polycyclic aromatic hydrocarbons in instant coffee  

Microsoft Academic Search

The essential aim of this work is the development of a simple, fast, quantitative and economic method for polycyclic aromatic hydrocarbons (PAHs) potentially generated by roasting coffee beans, which is the most important process in the coffee industry for the development of the characteristic flavour of the bean mix. The PAHs were chosen because they differed in the number of

Mercedes Sonia Garc??a-Falcón; Beatriz Cancho-Grande; Jesús Simal-Gándara

2005-01-01

416

Multipathway Polycyclic Aromatic Hydrocarbon and Pyrene Exposure Among Children Living in Campania (Italy)  

Microsoft Academic Search

Multipathway exposure to Polycyclic aromatic hydrocarbons (PAHs) and Pyrene (Py) was studied among children ages 7–9 living in two areas of the Campania Region (South-Italy) classified as urban and rural. During five consecutive days PAHs and Py were detected in air samples from outdoors, indoors (school and home), individuals at inhalatory levels, and in food and beverages (defined as food)

TERESA CIRILLO; PAOLO MONTUORI; PIERANGELA MAINARDI; IMMA RUSSO; MARIA TRIASSI; RENATA AMODIO-COCCHIERI

2006-01-01

417

TECHNICAL BASIS FOR NARCOTIC CHEMICALS AND POLYCYCLIC AROMATIC HYDROCARBON CRITERIA. II. MIXTURES AND SEDIMENTS  

Microsoft Academic Search

A method is presented for developing sediment quality guidelines (SQG) for narcotic chemicals in general and polycyclic aromatic hydrocarbons (PAHs) in particular. The guidelines can be applied to any individual or mixture of narcotic chemicals including PAHs using only the chemical's octanol\\/water partition coefficient. They are derived using the final chronic values for type I narcotics developed from a database

Dominic M. Di Toro; Joy A. McGrath

2000-01-01

418

Concentrations of particulate airborne polycyclic aromatic hydrocarbons and metals collected in Lahore, Pakistan  

Microsoft Academic Search

Hi-vol air sampling equipment was run at three sites (representative of “city”, “industrial” and “rural” sampling locations) in Lahore, Pakistan, for over a year. The extraction and quantitative analyses of all Lahore air samples was completed for a suite of metals, various anions, ammonium, elemental and organic carbon, as well as particle-associated polycyclic aromatic hydrocarbons (PAHs). A comparison of Lahore

D. J. T. Smith; Roy M. Harrison; L. Luhana; Casimiro A. Pio; L. M. Castro; Mohammad Nawaz Tariq; S. Hayat; T. Quraishi

1996-01-01

419

Basic Research on the Emission of Polycyclic Aromatic Hydrocarbons caused by Waste Incineration  

Microsoft Academic Search

The emission of polycyclic aromatic hydrocarbons (PAH) caused by municipal waste incineration varies according to waste composition and operating parameters such as furnace temperature and excess air. However, to obtain a sample sufficient to measure the emission of PAH at trace levels, it is necessary to operate the incinerator for many hours. Since during these lengthy periods it has not

Kenji Yasuda; Mikihiro Kaneko; Hidekichi Yoshino; Kooji Sugiyama; Yukio Ootsuka

1989-01-01

420

Qsars for photoinduced toxicity: 1. acute lethality of polycyclic aromatic hydrocarbons to daphnia magna'  

Microsoft Academic Search

Research with a variety of aquatic species has shown that while polycyclic aromatic hydrocarbons (PAHs) are generally not acutely toxic in conventional laboratory tests, many are extremely toxic in the presence of sunlight. In an effort to develop a model for predicting which PAHs may exhibit photo-induced toxicity, Newsted and Giesy (1987) reported a parabolic relationship between the toxicity and

O. G. Mekenyan; G. T. Ankley; G. D. Veith; D. J. Call

1994-01-01

421

Atmospheric concentrations of polycyclic aromatic hydrocarbons and selected nitrated derivatives in Greater Cairo, Egypt  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) and selected nitrated derivatives (NPAHs) in air were determined at two sites, El Dokki (a traffic site) and El Teppen (an industrial site) in Greater Cairo, Egypt, during the winter and summer seasons. The sites were selected to represent areas with different activities of Greater Cairo. The concentrations of fifteen PAHs having two to six rings

Hossam F. Nassar; Ning Tang; Takayuki Kameda; Akira Toriba; Mamdouh I. Khoder; Kazuichi Hayakawa

2011-01-01

422

Sampling precautions for the measurement of nitrated polycyclic aromatic hydrocarbons in ambient air  

Microsoft Academic Search

Because of the toxicity of polycyclic aromatic hydrocarbons (PAHs) and of their oxidation products, such as nitrated and oxygenated PAHs (NPAHs and OPAHs), the determination of their concentrations is of great interest in terms of atmospheric pollution control. Then, normalisation of sampling procedures appears essential. In this context, this paper presents a comparison of particulate PAH, OPAH and NPAH concentrations

A. Albinet; E. Leoz-Garziandia; H. Budzinski; E. ViIlenave

2007-01-01

423

Atmospheric Polycyclic Aromatic Hydrocarbons: An Aspect of Air Pollution in Fairbanks, Alaska  

Microsoft Academic Search

Quantitative analysis of atmospheric polycyclic aromatic hydrocarbons (PAH) in Fairbanks, Alaska revealed significant levels of representative components. A fairly constant PAH pattern was observed throughout the winter of 1976-77, and the absolute PAH level correlated with air stagnation. Consideration of relative levels of individual PAH components reveals vehicular emissions as the major source but also provides evidence for contributions from

PAUL B. REICHARDT; SUSAN K. REIDY

424

Numerical and Genetic Analysis of Polycyclic Aromatic Hydrocarbon-Degrading Mycobacteria  

Microsoft Academic Search

Ability to degrade high molecular weight polycyclic aromatic hydrocarbons (PAHs) has been found in diverse species of fast-growing mycobacteria. This study included several PAH-degrading mycobacteria from heavily contaminated sites and an uncontaminated humus soil in the Natural Park, Schwäbische Alb, Germany. The numerical analysis with a total of 131 tests showed that isolates from humus soil and contaminated sites had

Yong-Hak Kim; Karl-H. Engesser; Carl E. Cerniglia

2005-01-01

425

ELECTRON AFFINITIES OF POLYNUCLEAR AROMATIC HYDROCARBONS AND NEGATIVE ION CHEMICAL IONIZATION SENSITIVITIES  

EPA Science Inventory

Negative-ion chemical-ionization mass spectrometry (NICI MS) has the potential to be a very useful technique in identifying various polycyclic aromatic hydrocarbons (PAHs) in soil and sediment samples. Some PAHs give much stronger signals under NICI MS conditions than others. On ...

426

Metabolic diversity of aromatic hydrocarbon-degrading bacteria from a petroleum-contaminated aquifer  

Microsoft Academic Search

We characterized bacteria from contaminated aquifers for their ability to utilize aromatic hydrocarbons under hypoxic (oxygen-limiting) conditions (initial dissolved oxygen concentration about 2 mg\\/l) with nitrate as an alternate electron acceptor. This is relevant to current intense efforts to establish favorable conditions forin situ bioremediation. Using samples of granular activated carbon slurries from an operating groundwater treatment system, we isolated

Mark D. Mikesell; Jerome J. Kukor; Ronald H. Olsen

1993-01-01

427

Photodegradation of polycyclic aromatic hydrocarbons in fossil fuels catalysed by supported TiO 2  

Microsoft Academic Search

This paper describes the photodegradation behavior of polycyclic aromatic hydrocarbons present in different types of fossil fuels (commercial diesel, Arabian light crude, heavy fuel oil from the Prestige oil spill and coal from an abandoned coal dump) suspended in artificial seawater or ultrapure water, under irradiation in a stirred photochemical reactor for 14 days. The reactor was continuously fed with

Maria J. García-Martínez; Ignacio Da Riva; Laureano Canoira; Juan F. Llamas; Ramon Alcántara; Jose Luis R. Gallego

2006-01-01

428

HIGH PURITY PNA HYDROCARBONS AND OTHER AROMATIC COMPOUNDS. SYNTHESIS AND PURIFICATION  

EPA Science Inventory

The synthesis and/or purification of a group of polynuclear aromatic (PNA) hydrocarbons, commonly found as pollutants in the environment, are described. The steps used in a given synthesis, the experiments carried out, and a presentation of some instrumental data obtained in esta...

429

Photoinduced toxicity of the polycyclic aromatic hydrocarbon, fluoranthene, on the coral, Porites divaricata  

Microsoft Academic Search

The synergistic effect of ultraviolet radiation (UVR) and a polycyclic aromatic hydrocarbon (PAH) was tested on the coral Poritesdivaricata. Small branches were incubated in different concentrations of fluoranthene followed by exposure to ecologically relevant levels of natural solar radiation, with and without UVR. Exposure to the highest concentration of fluoranthene (60 ? g L) resulted in decreased photochemical efficiency of

María Del Carmen GuzmáN Martínez; Patricia Ramírez Romero; Anastazia T. Banaszak

2007-01-01

430

Characterization of a Polycyclic Aromatic Hydrocarbon–Degrading Microbial Consortium from a Petrochemical Sludge Landfarming Site  

Microsoft Academic Search

Anthracene, phenanthrene, and pyrene are polycyclic aromatic hydrocarbon (PAHs) that display both mutagenic and carcinogenic properties. They are recalcitrant to microbial degradation in soil and water due to their complex molecular structure and low solubility in water. This study presents the characterization of an efficient PAH (anthracene, phenanthrene, and pyrene)-degrading microbial consortium, isolated from a petrochemical sludge landfarming site. Soil

Rodrigo J. S. Jacques; Benedict C. Okeke; Fatima M. Bento; Maria C. R. Peralba; Flávio A. O. Camargo

2007-01-01

431

Reductive transformations of halogenated aromatic hydrocarbons in anaerobic water-sediment systems: Kinetics, mechanisms and products  

Microsoft Academic Search

The degradation of several classes of halogenated aromatic hydrocarbons in methanogenic sediment-water systems was examined in laboratory studies. Several transformation processes were shown to occur, leading to formation of a variety of products. In the study a clear distinction could be made between transformation processes taking place immediately upon incubation of the compounds and processes taking place after a characteristic

W. J. G. M. Peunenburg; Maarten J.'T Hart; Henri A. den Hollander; Dik van de Meent; Hans H. Verboom; N. Lee Wolfe

1992-01-01

432

Uptake of hydrophobic halogenated aromatic hydrocarbons from food by earthworms ( Eisenia andrei )  

Microsoft Academic Search

The intestinal uptake of hydrophobic halogenated aromatic hydrocarbons by the earthworm Eisenia andrei was studied. In one experiment, worms were fed a single dose of manure contaminated with three chlorobenzenes, one polychlorobiphenyl (PCB 153) and octachloronaphthalene (OCN). Body burdens were followed during the subsequent 6 days. In the second experiment, worms were fed penta- and hexachlorobenzene, using multiple oral doses

A. Belfroid; J. Meiling; D. Sijm; J. Hermens; W. Seinen; K. van Gestel

1994-01-01

433

Extraction of low molecular weight polynuclear aromatic hydrocarbons from ashes of coal-operated power plants  

SciTech Connect

A new procedure based on liquid-solid chromatography for the extraction of polynuclear aromatic hydrocarbons has been implemented. This yields results analogous to those of Soxhlet extraction for low molecular weight compounds. A very important reduction in the time required for sample preparation prior to gas chromatography/mass spectrometry analysis is obtained.

Mangani, F.; Cappiello, A.; Crescentini, G.; Bruner, F.; Bonfanti, L.

1987-09-01

434

Trace Metals and Polycyclic Aromatic Hydrocarbons in Surface Sediment Samples from the Narew River (Poland)  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons and trace metals were analysed in surface sediments of the Narew River (north-eastern Poland). Sediment samples originated from sites with a differentiated human influence starting with the unpolluted areas (the Biatowieza Forest \\/ Puszcza Bialowieska, the so-called \\

S. Baran; P. Oleszczuk; A. Lesiuk; E. Baranowska

435

POLYCYCLIC AROMATIC HYDROCARBON BIODEGRADATION AS A FUNCTION OF OXYGEN TENSION IN CONTAMINATED SOIL  

EPA Science Inventory

Laboratory tests were conducted to determine the effect of soil gas oxygen concentration on the degradation and mineralization of spiked 14C-pyrene and nonspiked 16 priority pollutant polycyclic aromatic hydrocarbons (PAH) present in the soil. The soil used for the evaluation was...

436

Comparison of drinking-water mutagenicity with leaching of polycyclic aromatic hydrocarbons from water distribution pipes  

Microsoft Academic Search

The primary objectives of this study were to examine the changes in concentration of six polycyclic aromatic hydrocarbons (PAH) and the possibility of changes in mutagenic potential of treated waters as a result of their passage through commonly used distribution pipes. With the exception of the finished water taken at one treatment plant in which the total concentration of the

D. K. Basu; J. Saxena; F. W. Stoss; J. Santodonato; M. W. Neal

1987-01-01

437

Optimisation and validation of an HPLC method for determination of polycyclic aromatic hydrocarbons (PAHs) in mussels  

Microsoft Academic Search

A method for determination of 11 polycyclic aromatic hydrocarbons (PAHs) in mussels (Mytilus galloprovincialis), using HPLC coupled to a fluorescence detector, has been optimised and validated, according to European Community rules. Sample preparation involves alkaline digestion of mussel tissue, liquid–liquid extraction of organic compounds and solid phase clean-up. Accuracy and precision of the method were determined by a validation study,

Francesco Paolo Serpe; Mauro Esposito; Pasquale Gallo; Luigi Serpe

2010-01-01

438

Trace elements and polycyclic aromatic hydrocarbons (PAHs) concentrations in deep Gulf of Mexico sediments  

Microsoft Academic Search

The concentrations of polycyclic aromatic hydrocarbons (PAHs) and trace elements were determined for surface (top 2cm) sediment samples collected during the deep Gulf of Mexico benthos (DGoMB) study .These elements and compounds are known to be toxic to organisms at high concentrations and may affect biological communities. There is no indication of major anthropogenic input of the elements Be, Co,

Terry L. Wade; Yousra Soliman; Stephen T. Sweet; Gary A. Wolff; Bobby J. Presley

2008-01-01

439

Measurement of vapor deposition and extraction recovery of polycyclic aromatic hydrocarbons adsorbed on particulate solids  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs), released (in the vapor phase) into the atmosphere via combustion of fossil fuels, are believed to adsorb on atmospheric particulate surfaces. The chemical behavior of an adsorbed PAH is strongly dependent on the characteristics of the adsorbent. Studies of chemical transformations of adsorbed PAHs usually require that the PAHs and\\/or their transformation products be extracted from

Robert J. Engelbach; Arlene A. Garrison; E. L. Wehry; Gleb. Mamantov

1987-01-01

440

The adsorption of saturated and aromatic hydrocarbon vapors on silicas with chemically grafted perfluorohexyl groups  

Microsoft Academic Search

Regardless of the nature of the modifier (mono-, bi-, and trichlorosilanes with perfluorohexyl groups or monochlorooctylsilane), the modification of silica decreased retention volumes and adsorption values of both n-alkanes and aromatic hydrocarbons. The entropy factor can play a key role in adsorption intermolecular interactions on the surface of chemically modified silicas. The modification of the surface with bi-and trichloroperfluorohexylsilanes caused

T. M. Roshchina; N. K. Shoniya; M. S. Lagutova; A. Yu. Fadeev

2008-01-01

441

Effects of toasting procedures on the levels of polycyclic aromatic hydrocarbons in toasted bread  

Microsoft Academic Search

Some polycyclic aromatic hydrocarbons (PAHs), particularly those with a high molecular weight, have been classified as probably carcinogens to humans by the International Agency for Research on Cancer (IARC). The significance of the determination of PAHs is reflected by the special attention of the European Union, which is paying to regulate the maximum allowed levels of PAHs in foodstuffs such

Ledicia Rey-Salgueiro; Mercedes Sonia García-Falcón; Elena Martínez-Carballo; Jesús Simal-Gándara

2008-01-01

442

Phagocytic reduction and effects on lysosomal membranes by polycyclic aromatic hydrocarbons, in haemocytes of Mytilus edulis  

Microsoft Academic Search

The effects of certain polycyclic aromatic hydrocarbons (PAHs) on the immune reactivity of haemocytes from Mytilus edulis were investigated by means of a series of in vitro and in vivo experiments, utilizing phagocytosis and neutral red uptake or lysosomal neutral red retention assays. Cells in vitro were exposed to 8.3, 16.6, 25 or 50 ppm of anthracene, fluoranthene or phenanthrene,

M. M. Grundy; M. N. Moore; S. M. Howell; N. A. Ratcliffe

1996-01-01

443

Effect of irradiance spectra on the photoinduced toxicity of three polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) is dependent on the concentration of compounds present and the dose of light received. Of the light present, only those wavelengths absorbed by the compound have the potential to initiate the photochemical events underlying phototoxicity. This suggests that variation in light spectra present in natural waters, arising from variation in dissolved organic carbon

S. A. Diamond; D. R. Mount; L. P. Burkhard; G. T. Ankley; E. A. Makynen; E. N. Leonard

2000-01-01

444

Polycyclic Aromatic Hydrocarbons in the Arctic: Ob and Yenisei Estuaries and Kara Sea Shelf  

Microsoft Academic Search

Suspended matter (SM) and surface sediments were analysed for polycyclic aromatic hydrocarbons (PAH) throughout the Ob and Yenisei River estuaries and in the Kara Sea in order to evaluate the contamination of Arctic shelves by these two major Siberian rivers. PAH concentrations were extremely low, among the lowest measured up to now in the Arctic region. Particle-associated PAH were in

M. B. Fernandes; M.-A. Sicre

1999-01-01

445

Polycyclic aromatic hydrocarbon exposures of children in low-income families1  

Microsoft Academic Search

Children in low-income families may have high exposures to polycyclic aromatic hydrocarbons (PAH). Such exposures could result from household proximity to heavy traffic or industrial sources, environmental tobacco smoke, contaminated house dust or soil, among others. The objectives of this study were: to establish methods for measuring total PAH exposure of children in low-income families, to estimate the PAH exposures

JANE C CHUANG; PATRICK J CALLAHAN; CHRISTOPHER W LYU; NANCY K WILSON

1999-01-01

446

Leaching of heavy metals and polycyclic aromatic hydrocarbons from reclaimed asphalt pavement  

Microsoft Academic Search

The work presented herein displays the results of a study addressing environmental concerns related to the possible leaching of pollutants from reclaimed asphalt pavement. Samples from an experimental site were tested in both static batch tests and column leaching tests. Selected heavy metals and polycyclic aromatic hydrocarbons (PAHs) were analysed in leachates. The results have allowed us to consider the

M. Legret; L. Odie; D. Demare; A. Jullien

2005-01-01

447

Characterization of polycyclic aromatic compounds in diesel exhaust particulate extract responsible for aryl hydrocarbon receptor activity  

NASA Astrophysics Data System (ADS)

Chemical fractions of a model diesel exhaust particulate extract, notably the fraction containing polycyclic aromatic hydrocarbons (PAH) (Fraction II), mono-nitro PAH (Fraction III), and dinitro-PAH (Fraction IV) have been shown to displace binding of 2,3,7,8-tetrachloro[1,6-[ 3H

Soontjens, Carol D.; Holmberg, Kristina; Westerholm, Roger N.; Rafter, Joseph J.

448

Defects in cardiac function precede morphological abnormalities in fish embryos exposed to polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Fish embryos exposed to complex mixtures of polycyclic aromatic hydrocarbons (PAHs) from petrogenic sources show a characteristic suite of abnormalities, including cardiac dysfunction, edema, spinal curvature, and reduction in the size of the jaw and other craniofacial structures. To elucidate the toxic mechanisms underlying these different defects, we exposed zebrafish (Danio rerio) embryos to seven non-alkylated PAHs, including five two-

John P. Incardona; Tracy K. Collier; Nathaniel L. Scholz

2004-01-01

449

Experimental investigation of the atmospheric chemistry of aromatic hydrocarbons and long-chain alkanes. Final report  

Microsoft Academic Search

The interaction of volatile organic compounds (VOCs) and oxides of nitrogen in the presence of sunlight leads to the formation of ozone and other manifestations of photochemical air pollution. There are, however, significant uncertainties in our knowledge of the products and mechanisms of the atmospheric reactions of alkanes and aromatic hydrocarbons, important constituents of ambient air in urban areas, with

R. Atkinson; J. Arey; E. C. Tuazon; S. M. Aschmann; I. Bridier

1994-01-01

450

Polycyclic aromatic hydrocarbons in harp seals ( Phoca groenlandica ) from the Northwest Atlantic  

Microsoft Academic Search

There is virtually no information available on concentrations of polycyclic aromatic hydrocarbons (PAH) in seals from any of the world's oceans. The largest harp seal population in the world is found in Canadian waters of the Northwest Atlantic. Samples of muscle tissue obtained from twenty eight harp seals ranging in age from foetuses to animals 22 years old were analyzed

J. Hellou; C. Upshall; I. H. Ni; J. F. Payne; Y. S. Huang

1991-01-01

451

Influence of steroid structure on the pyrolytic formation of polycyclic aromatic hydrocarbons  

Microsoft Academic Search

It is well known that polycyclic aromatic hydrocarbons (PAHs) are formed from the pyrolysis of biomass, but the precursors and pathways that lead to PAHs are not well characterized. In this investigation, the flash vacuum pyrolysis (FVP) and the atmospheric pressure flow pyrolysis of a series of structurally different plant steroids, including stigmasterol, stigmasteryl acetate, ?-sitosterol, stigmasta-3,5-diene, cholesterol, cholesteryl acetate,

Phillip F. Britt; A. C. Buchanan; Michelle K. Kidder; Clyde V. Owens

2003-01-01

452

DEGRADATION OF POLYNUCLEAR AROMATIC HYDROCARBONS UNDER BENCH-SCALE COMPOST CONDITIONS  

EPA Science Inventory

The relationship between biomass growth and degradation of polynuclear aromatic hydrocarbons (PAHs) in soil, and subsequent toxicity reduction, was evaluated in 10 in-vessel, bench-scale compost units. Field soil was aquired from the Reilly Tar and Chemical Company Superfund site...

453

Chromosomal Aberrations in Cord Blood Are Associated with Prenatal Exposure to Carcinogenic Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

Molecular and traditional epidemiology studies have indicated a possible relationship between in utero environ- mental exposures and increased risk for childhood cancers, especially acute leukemias. Chromosomal aberrations have been associated with environmental exposures and cancer risk in adults. In order to more clearly define the association between prenatal exposures to carcinogenic polycyclic aromatic hydrocarbons (PAH) and chromosomal aberrations, chromosomal aberration

Kirsti A. Bocskay; Deliang Tang; Manuela A. Orjuela; Dorothy P. Warburton; Frederica P. Perera; Joseph L. Mailman

2005-01-01

454

Occurrence of polycyclic aromatic hydrocarbons throughout the processing stages of erva-mate (Ilex paraguariensis)  

Microsoft Academic Search

The presence of polycyclic aromatic hydrocarbons (PAHs) in mate (Ilex paraguariensis) is believed to be due to the degradation of mate compounds and the burning of wood during the “sapeco” (rapid drying process) and the final drying steps, which are the most important processing stages in mate production. Due to the high toxicity of these compounds, studies on their presence

Manoela Alano Vieira; Marcelo Maraschin; Ângela Angeloni Rovaris; Renata Dias de Mello Castanho Amboni; Cristiane Manfé Pagliosa; José Júnior Mendonça Xavier; Edna Regina Amante

2010-01-01

455

DNA adducts as a measure of lung cancer risk in humans exposed to polycyclic aromatic hydrocarbons  

Microsoft Academic Search

Workers in the coking, foundry, and aluminum industry can be exposed to high concentrations of polycyclic aromatic hydrocarbons (PAHs) and are at increased risk for lung cancer, as are cigarette smokers. In recent years several studies on workers in the foundry and coking industries have been reported. In these studies, white blood cell (WBC) DNA was used for analysis of

E. Kriek; F. J. Van Schooten; M. J. X. Hillebrand; F. E. Van Leeuwen; L. Den Engelse; A. J. A. De Looff; A. P. G. Dijkmans

1993-01-01

456

Exposure to polycyclic aromatic hydrocarbons and missed abortion in early pregnancy in a Chinese population  

Microsoft Academic Search

BackgroundPolycyclic aromatic hydrocarbons (PAHs) are formed during incomplete burning of fossil fuels, wood, and tobacco products. High PAH exposure has been associated with low birth weight, intrauterine growth restriction, and preterm birth, but little is known about its impact on adverse outcomes in early pregnancy such as in-utero fetal death.

Jun Wu; Haiyan Hou; Beate Ritz; Yaqiong Chen

2010-01-01

457

Polycyclic aromatic hydrocarbons (PAHs) in burning and non-burning coal waste piles  

Microsoft Academic Search

The coal waste material that results from Douro Coalfield exploitation was analyzed by gas chromatography with mass spectrometry (GC–MS) for the identification and quantification of the 16 polycyclic aromatic hydrocarbons (PAHs), defined as priority pollutants. It is expected that the organic fraction of the coal waste material contains PAHs from petrogenic origin, and also from pyrolytic origin in burning coal

Joana Ribeiro; Tais Silva; Joao Graciano Mendonca Filho; Deolinda Flores

458

Photochemical Degradation of Polycyclic Aromatic and Nitroaromatic Hydrocarbons in the Urban Atmosphere  

Microsoft Academic Search

Possible mechanisms of the photochemical conversion of polycyclic aromatic and nitroaromatic hydrocarbons in the urban atmosphere under the action of sunlight were analyzed. A kinetic model of the process was proposed, which takes into account the emission of harmful substances and the deposition of these substances onto the Earth's surface. It was found that emission is a predominant process within

G. Ya. Gerasimov

2004-01-01

459

Urban Runoff Contribution to Surface Sediment Accumulation for Polycyclic Aromatic Hydrocarbons in the Cotonou Lagoon, Benin  

Microsoft Academic Search

The carcinogenic and mutagenic properties of some polycyclic aromatic hydrocarbons (PAHs) and their widespread presence in the environment have led to many scientific investigations during the past three decades. In this study, surface sediments from six sampling sites in the Cotonou lagoon (three sites in the channel and three in Lake Nokoue) during the highest stormy season (May, June, and

H. H. Soclo; A. Affokpon; A. Sagbo; S. Thomson; H. Budzinski; P. Garrigues; S. Matsuzawa; A. Rababah

2002-01-01

460

WATERSHED-BASED SOURCES OF POLYCYCLIC AROMATIC HYDROCARBONS IN URBAN STORM WATER  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic and mutagenic compounds, ubiquitous in the air and water of urban environments, and have been shown to accumulate in coastal estuarine and marine sediments. Although previous studies have documented concentrations and loads of PAHs in urban runoff, little is known about the sources and temporal patterns of PAH loading from storm water. This study

Eric D. Stein; Liesl L. Tiefenthaler; Kenneth Schiff

2006-01-01

461

Molecular transport of aromatic hydrocarbons through crosslinked styrene-butadiene rubber membranes  

Microsoft Academic Search

Molecular transport of aromatic hydrocarbons through crosslinked SBR has been carried out in the temperature range (25–65°C). SBR has been vulcanized by four different vulcanizing techniques viz., conventional, efficient, dicumyl peroxide and a mixture consisting of sulfur and peroxide. SBR vulcanized with EV system showed highest solvent uptake tendency and that vulcanized with peroxide showed the lowest. The influence of

K. N. Ninan

1996-01-01

462

Dry deposition of particulate polychlorinated biphenyls and polycyclic aromatic hydrocarbons to Lake Michigan  

Microsoft Academic Search

Dry deposition was collected from November 1993 to October 1995 at multiple sites within the Lake Michigan basin to estimate fluxes of particulate polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) as part of the Lake Michigan Mass Balance Study (LMMBS). Samples were also collected during the Atmospheric Exchange over Lakes and Oceans (AEOLOS) project to estimate fluxes to coastal

Thomas P. Franz; Steven J. Eisenreich; Thomas M. Holsen

1998-01-01

463

Development of a catabolically significant genetic probe for polycyclic aromatic hydrocarbon-degrading Mycobacteria in soil  

Microsoft Academic Search

A gene probe for the detection of polycyclic aromatic hydrocarbon (PAH) induced nidB and nidA dioxygenase genes has been designed from Mycobacteria JLS, KMS, and MCS. The probe detects a catabolic gene involved in the initial steps of PAH biodegradation in mycobacteria. The gene probe is comprised of three PCR primer sets designed to detect the genes that code for

Kevin Hall; Charles D. Miller; Darwin L. Sorensen; Anne J. Anderson; Ronald C. Sims

2005-01-01

464

Enumeration and phylogenetic analysis of polycyclic aromatic hydrocarbon-degrading marine bacteria from Puget Sound sediments  

SciTech Connect

Polycyclic aromatic hydrocarbons (PAHs) are primarily released into the environment through anthropomorphic sources. PAH degradation has been known to occur in marine sediments. This paper describes the enumeration, isolation, and preliminary characterization of PAH-degrading strains from Puget Sound sediments. 38 refs., 3 figs., 3 tabs.

Geiselbrecht, A.D.; Herwig, R.P.; Deming, J.W.; Staley, J.T. [Univ. of Washington, Seattle, WA (United States)

1996-09-01

465

Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by Cladosporium sphaerospermum isolated from an aged PAH contaminated soil  

Microsoft Academic Search

The ability of a Deuteromycete fungus, Cladosporium sphaerospermum, previously isolated from soil of an aged gas manufacturing plant, to degrade polycyclic aromatic hydrocarbons was investigated. This strain was able to degrade PAHs in non-sterile soils (average 23%), including high molecular weight PAHs, after 4 weeks of incubation. In a microcosm experiment, PAH depletion was clearly correlated to fungal establishment. In

Olivier Potin; Etienne Veignie; Catherine Rafin

2004-01-01

466

Bacterial biodegradation of polycyclic aromatic hydrocarbons (PAH) and potential effects of surfactants on PAH bioavailability  

Microsoft Academic Search

The purposes of this project were to evaluate whether indigenous microorganisms from polycyclic aromatic hydrocarbons (PAH)-contaminated soils produce surfactants (biosurfactants) as a means of enhancing the bioavailability of PAH; to improve the understanding of the general physiology of a diverse group of PAH-degrading bacteria; and to study in general how surfactants influence the biodegradation of hydrophobic chemicals.

M. D. Aitken; S. J. Grimberg; J. Nagel; R. D. Nagel; W. T. Stringfellow

1996-01-01

467

Near-Critical and Supercritical Fluid Extraction of Polycyclic Aromatic Hydrocarbons from Town Gas Soil  

Microsoft Academic Search

The contamination of soil by hazardous and toxic organic pollutants is an ever-growing problem facing the global community. One particular family of contaminants that are of major importance are polycyclic aromatic hydrocarbons (PAHs). PAHs are the result of coal gassification and high-temperature processes. Sludges from these town gas operations were generally disposed of into unlined pits and left there for

BRIAN S. KOCHER; FOUAD O. AZZAM; TERESA J. CUTRIGHT; SUNGGYU LEE

1995-01-01

468

Historical Distribution of Polycyclic Aromatic Hydrocarbons in Shallow Sediments from Lake Chapala, Mexico  

Microsoft Academic Search

The incomplete combustion of fossil fuels and burning of vegetation and other organic materials release into the environment pollutants like polycyclic aromatic hydrocarbons (PAHs) which are ubiquitous pollutants. The environmental behavior of PAHs is characterized by very low solubility, high hydrophobic sorptive capacity (kow), low volatility and general chemical stability. These characteristics mean, in practice, that PAHs are environmentally persistent

P. F. Zárate-Del Valle; M. P. Macías-Pérez; C. D. Barajas-Martínez; C. M. Gómez-Hermosillo

2008-01-01

469

Polycyclic Aromatic Hydrocarbons in Fishes and Sediments from the Guanabara Bay, Brazil  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) were identified and quantified in sediment and fish samples. The samples were analyzed by gas chromatography\\/mass spectrometry to gather information about the degree of contamination. PAH total concentration ranged from 79 to 487 ? g\\/kg dry weight in surficial sediment samples and from 4 to 53 ? g\\/kg in fish samples. Most sediment samples were classified

Taís Freitas da Silva; Débora de Almeida Azevedo; Francisco Radler de Aquino Neto

2007-01-01

470

Polycyclic aromatic hydrocarbon burden in ambient air in selected Niger Delta communities in Nigeria  

Microsoft Academic Search

The Niger Delta area in Nigeria has major oil producing and refining centers that characterized enormous industrial activities, especially in the petroleum sector. These industrial processes release different kinds of atmospheric pollutants, of which there is paucity of information on their levels and health implications. The objective of this study was to determine the ambient levels of polycyclic aromatic hydrocarbons

G. R. E. E. Ana; M. K. C. Sridhar; G. O. Emerole

2012-01-01

471

Effectiveness of Phytoremediation as a Secondary Treatment for Polycyclic Aromatic Hydrocarbons (PAHs) in Composted Soil  

Microsoft Academic Search

A greenhouse study was conducted over a 12-month period to investigate the fate of polycyclic aromatic hydrocarbons (PAHs) in soil using phytoremediation as a secondary treatment. The soil was pretreated by composting for 12 weeks, then planted with tall fescue (Festuca arundinacea), annual ryegrass (Lolium multiflorum), and yellow sweet clover (Melilotus officinalis). Two sets of unvegetated controls also were evaluated,

Zakia D. Parrish; M. Katherine Banks; A. Paul Schwab

2004-01-01

472

Aerosol formation studies on aromatic hydrocarbons in the EUPHORE outdoor simulation chamber  

Microsoft Academic Search

The present work is an experimental study on the formation of secondary organic aerosol during the photochemical oxidation of aromatic hydrocarbons in an environmental smog chamber under realistic conditions, i.e., low precursor concentrations and natural solar irradiation. A series of newly designed smog chamber irradiations were performed in the EUPHORE chambers (Valencia, Spain) in which concentration levels of precursors were

K. Wirtz; M. Martin-Reviejo; E. Borras

2003-01-01

473

CALCULATION OF ELECTRON AFFINITIES OF POLYCYCLIC AROMATIC HYDROCARBONS AND SOVATION ENERGIES OF THEIR ANIONS  

EPA Science Inventory

Electron affinities (EAs) and free energies for electron attachment have been calculated for 42 polynuclear aromatic hydrocarbons and related molecules by a variety of theoretical models, including Koopmans' theorem methods and the L1E method from differences in energy between th...

474

Environmental assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Santander Bay, Northern Spain  

Microsoft Academic Search

Samples of intertidal surface sediments (0–2 cm) were collected in 17 stations of the Santander Bay, Cantabric Sea, Northern Spain. The concentrations of polycyclic aromatic hydrocarbons (PAHs), 16, were analysed by HPLC and MS detection. Surface sediments show a good linear correlation among the parameters of the experimental organic matter evaluation, where total carbon (TC) and loss on ignition (LOI)

J. Viguri; J. Verde; A. Irabien

2002-01-01