Polycyclic Aromatic Hydrocarbons: A Critical Review of Environmental Occurrence and Bioremediation.

PubMed

Alegbeleye, Oluwadara Oluwaseun; Opeolu, Beatrice Oluwatoyin; Jackson, Vanessa Angela

2017-10-01

The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. The importance of the need for sustainable abatement strategies to alleviate contamination therefore cannot be overemphasised, as daily human activities continue to create pollution from polycyclic aromatic hydrocarbons and impact the natural environment. Globally, attempts have been made to design treatment schemes for the remediation and restoration of contaminated sites. Several techniques and technologies have been proposed and tested over time, the majority of which have significant limitations. This has necessitated research into environmentally friendly and cost-effective clean-up techniques. Bioremediation is an appealing option that has been extensively researched and adopted as it has been proven to be relatively cost-effective, environmentally friendly and is publicly accepted. In this review, the physicochemical properties of some priority polycyclic aromatic hydrocarbons, as well as the pathways and mechanisms through which they enter the soil, river systems, drinking water, groundwater and food are succinctly examined. Their effects on human health, other living organisms, the aquatic ecosystem, as well as soil microbiota are also elucidated. The persistence and bioavailability of polycyclic aromatic hydrocarbons are discussed as well, as they are important factors that influence the rate, efficiency and overall success of remediation. Bioremediation (aerobic and anaerobic), use of biosurfactants and bioreactors, as well as the roles of biofilms in the biological treatment of polycyclic aromatic hydrocarbons are also explored.

Polycyclic Aromatic Hydrocarbons: A Critical Review of Environmental Occurrence and Bioremediation

NASA Astrophysics Data System (ADS)

Alegbeleye, Oluwadara Oluwaseun; Opeolu, Beatrice Oluwatoyin; Jackson, Vanessa Angela

2017-10-01

The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. The importance of the need for sustainable abatement strategies to alleviate contamination therefore cannot be overemphasised, as daily human activities continue to create pollution from polycyclic aromatic hydrocarbons and impact the natural environment. Globally, attempts have been made to design treatment schemes for the remediation and restoration of contaminated sites. Several techniques and technologies have been proposed and tested over time, the majority of which have significant limitations. This has necessitated research into environmentally friendly and cost-effective clean-up techniques. Bioremediation is an appealing option that has been extensively researched and adopted as it has been proven to be relatively cost-effective, environmentally friendly and is publicly accepted. In this review, the physicochemical properties of some priority polycyclic aromatic hydrocarbons, as well as the pathways and mechanisms through which they enter the soil, river systems, drinking water, groundwater and food are succinctly examined. Their effects on human health, other living organisms, the aquatic ecosystem, as well as soil microbiota are also elucidated. The persistence and bioavailability of polycyclic aromatic hydrocarbons are discussed as well, as they are important factors that influence the rate, efficiency and overall success of remediation. Bioremediation (aerobic and anaerobic), use of biosurfactants and bioreactors, as well as the roles of biofilms in the biological treatment of polycyclic aromatic hydrocarbons are also explored.

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...

Airborne Exposures to Polycyclic Aromatic Compounds Among Workers in Asphalt Roofing Manufacturing Facilities.

PubMed

Trumbore, David C; Osborn, Linda V; Johnson, Kathleen A; Fayerweather, William E

2015-01-01

We studied exposure of 151 workers to polycyclic aromatic compounds and asphalt emissions during the manufacturing of asphalt roofing products-including 64 workers from 10 asphalt plants producing oxidized, straight-run, cutback, and wax- or polymer-modified asphalts, and 87 workers from 11 roofing plants producing asphalt shingles and granulated roll roofing. The facilities were located throughout the United States and used asphalt from many refiners and crude oils. This article helps fill a gap in exposure data for asphalt roofing manufacturing workers by using a fluorescence technique that targets biologically active 4-6 ring polycyclic aromatic compounds and is strongly correlated with carcinogenic activity in animal studies. Worker exposures to polycyclic aromatic compounds were compared between manufacturing plants, at different temperatures and using different raw materials, and to important external benchmarks. High levels of fine limestone particulate in the plant air during roofing manufacturing increased polycyclic aromatic compound exposure, resulting in the hypothesis that the particulate brought adsorbed polycyclic aromatic compounds to the worker breathing zone. Elevated asphalt temperatures increased exposures during the pouring of asphalt. Co-exposures in these workplaces which act as confounders for both the measurement of total organic matter and fluorescence were detected and their influence discussed. Exposures to polycyclic aromatic compounds in asphalt roofing manufacturing facilities were lower than or similar to those reported in hot-mix paving application studies, and much below those reported in studies of hot application of built-up roofing asphalt. These relatively low exposures in manufacturing are primarily attributed to air emission controls in the facilities, and the relatively moderate temperatures, compared to built-up roofing, used in these facilities for oxidized asphalt. The exposure to polycyclic aromatic compounds was a very small part of the overall worker exposure to asphalt fume, on average less than 0.07% of the benzene-soluble fraction. Measurements of benzene-soluble fraction were uniformly below the American Conference of Governmental Industrial Hygienists' Threshold Limit Value for asphalt fume.

Fusing porphyrins with polycyclic aromatic hydrocarbons and heterocycles for optoelectronic applications

DOEpatents

Thompson, Mark E.; Diev, Viacheslav; Hanson, Kenneth; Forrest, Stephen R.

2015-08-18

A compound that can be used as a donor material in organic photovoltaic devices comprising a non-activated porphyrin fused with one or more non-activated polycyclic aromatic rings or one or more non-activated heterocyclic rings can be obtained by a thermal fusion process. The compounds can include structures of Formula I: ##STR00001## By heating the reaction mixture of non-activated porphyrins with non-activated polycyclic aromatic rings or heterocyclic rings to a fusion temperature and holding for a predetermined time, fusion of one or more polycyclic rings or heterocyclic rings to the non-activated porphyrin core in meso,.beta. fashion is achieved resulting in hybrid structures containing a distorted porphyrin ring with annulated aromatic rings. The porphyrin core can be olygoporphyrins.

Determination of 15 polycyclic aromatic hydrocarbons in aquatic products by solid-phase extraction and GC-MS.

PubMed

Liu, Qiying; Guo, Yuanming; Sun, Xiumei; Hao, Qing; Cheng, Xin; Zhang, Lu

2018-02-22

We propose a method for the simultaneous determination of 15 kinds of polycyclic aromatic hydrocarbons in marine samples (muscle) employing gas chromatography with mass spectrometry after saponification with ultrasound-assisted extraction and solid-phase extraction. The experimental conditions were optimized by the response surface method. In addition, the effects of different lyes and extractants on polycyclic aromatic hydrocarbons extraction were discussed, and saturated sodium carbonate was first used as the primary saponification reaction and extracted with 10 mL of ethyl acetate and secondly 1 mol/L of sodium hydroxide and 10 mL of n-hexane were used to achieve better results. The average recovery was 67-112%. Satisfactory data showed that the method has good reproducibility with a relative standard deviation of <13%. The detection limits of polycyclic aromatic hydrocarbons were 0.02-0.13 ng/g. Compared with other methods, this method has the advantages of simple pretreatment, low solvent consumption, maximum polycyclic aromatic hydrocarbons extraction, the fast separation speed, and the high extraction efficiency. It is concluded that this method meets the batch processing requirements of the sample and can also be used to determine polycyclic aromatic hydrocarbons in other high-fat (fish, shrimp, crab, shellfish) biological samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization and determination of polycyclic aromatic hydrocarbons in biochar-based fertilizers.

PubMed

Chen, Ping; Zhou, Hui; Gan, Jay; Sun, Mingxing; Shang, Guofeng; Liu, Liang; Shen, Guoqing

2015-03-01

The agronomic benefit of biochar has attracted widespread attention to biochar-based fertilizers. However, the inevitable presence of polycyclic aromatic hydrocarbons in biochar is a matter of concern because of the health and ecological risks of these compounds. The strong adsorption of polycyclic aromatic hydrocarbons to biochar complicates their analysis and extraction from biochar-based fertilizers. In this study, we optimized and validated a method for determining the 16 priority polycyclic aromatic hydrocarbons in biochar-based fertilizers. Results showed that accelerated solvent extraction exhibited high extraction efficiency. Based on a Box-Behnken design with a triplicate central point, accelerated solvent extraction was used under the following optimal operational conditions: extraction temperature of 78°C, extraction time of 17 min, and two static cycles. The optimized method was validated by assessing the linearity of analysis, limit of detection, limit of quantification, recovery, and application to real samples. The results showed that the 16 polycyclic aromatic hydrocarbons exhibited good linearity, with a correlation coefficient of 0.996. The limits of detection varied between 0.001 (phenanthrene) and 0.021 mg/g (benzo[ghi]perylene), and the limits of quantification varied between 0.004 (phenanthrene) and 0.069 mg/g (benzo[ghi]perylene). The relative recoveries of the 16 polycyclic aromatic hydrocarbons were 70.26-102.99%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Δg: The new aromaticity index based on g-factor calculation applied for polycyclic benzene rings

NASA Astrophysics Data System (ADS)

Ucun, Fatih; Tokatlı, Ahmet

2015-02-01

In this work, the aromaticity of polycyclic benzene rings was evaluated by the calculation of g-factor for a hydrogen placed perpendicularly at geometrical center of related ring plane at a distance of 1.2 Å. The results have compared with the other commonly used aromatic indices, such as HOMA, NICSs, PDI, FLU, MCI, CTED and, generally been found to be in agreement with them. So, it was proposed that the calculation of the average g-factor as Δg could be applied to study the aromaticity of polycyclic benzene rings without any restriction in the number of benzene rings as a new magnetic-based aromaticity index.

Absorption of nitro-polycyclic aromatic hydrocarbons by biomembrane models: effect of the medium lipophilicity.

PubMed

Castelli, Francesco; Micieli, Dorotea; Ottimo, Sara; Minniti, Zelica; Sarpietro, Maria Grazia; Librando, Vito

2008-10-01

To demonstrate the relationship between the structure of nitro-polycyclic aromatic hydrocarbons and their effect on biomembranes, we have investigated the influence of three structurally different nitro-polycyclic aromatic hydrocarbons, 2-nitrofluorene, 2,7-dinitrofluorene and 3-nitrofluoranthene, on the thermotropic behavior of dimyristoylphosphatidylcholine multilamellar vesicles, used as biomembrane models, by means of differential scanning calorimetry. The obtained results indicate that the studied nitro-polycyclic aromatic hydrocarbons affected the thermotropic behavior of multilamellar vesicles to various extents, modifying the pretransition and the main phase transition peaks and shifting them to lower temperatures. The effect of the aqueous and lipophilic medium on the absorption process of these compounds by the biomembrane models has been also investigated revealing that the process is hindered by the aqueous medium but strongly allowed by the lipophilic medium.

[Simultaneous determination of 15 polycyclic aromatic hydrocarbons in cigarette filter by gas chromatography-tandem mass spectrometry].

PubMed

Zhang, Xiaotao; Zhang, Li; Ruan, Yibin; Wang, Weiwei; Ji, Houwei; Wan, Qiang; Lin, Fucheng; Liu, Jian

2017-10-08

A method for the simultaneous determination of 15 polycyclic aromatic hydrocarbons in cigarette filter was developed by isotope internal standard combined with gas chromatography-tandem mass spectrometry. The cigarette filters were extracted with dichloromethane, and the extract was filtered with 0.22 μm organic phase membrane. The samples were isolated by DB-5MS column (30 m×0.25 mm, 0.25 μm) and detected using multiple reaction monitoring mode of electron impact source under positive ion mode. The linearities of the 15 polycyclic aromatic hydrocarbons (acenapthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, ben[ a ]anthracene, chrysene, benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene, dibenzo[ a,h ]anthracene, benzo[ g,h,i ]perylene and indeno[1,2,3- c,d ]pyrene) were good, and the correlation coefficients ( R 2 ) ranged from 0.9914 to 0.9999. The average recoveries of the 15 polycyclic aromatic hydrocarbons were 81.6%-109.6% at low, middle and high spiked levels, and the relative standard deviations were less than 16%, except that the relative standard deviation of fluorene at the low spiked level was 19.2%. The limits of detection of the 15 polycyclic aromatic hydrocarbons were 0.02 to 0.24 ng/filter, and the limits of quantification were 0.04 to 0.80 ng/filter. The method is simple, rapid, accurate, sensitive and reproducible. It is suitable for the quantitative analysis of the 15 polycyclic aromatic hydrocarbons in cigarette filters.

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, ...

MULTISUBSTRATE BIODEGRADATION KINETICS FOR BINARY AND COMPLEX MIXTURES OF POLYCYCLIC AROMATIC HYDROCARBONS

EPA Science Inventory

Biodegradation kinetics were studied for binary and complex mixtures of nine polycyclic aromatic hydrocarbons (PAHs): naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 2-ethylnaphthalene, phenanthrene, anthracene, pyrene, fluorene and fluoranthene. Discrepancies between the ...

Polytetrafluoroethylene-jacketed stirrer modified with graphene oxide and polydopamine for the efficient extraction of polycyclic aromatic hydrocarbons.

PubMed

Zhang, Zinxin; Mwadini, Mwadini Ahmada; Chen, Zilin

2016-10-01

Steel stirrers jacketed with polytetrafluoroethylene can be regarded as an ideal substrate for stirrer bar sorptive extraction. However, it is still a great challenge to immobilize graphene onto a polytetrafluoroethylene stirrer due to the high chemical resistance of the surface of a polytetrafluoroethylene stirrer. We describe here a method to modify the surface of polytetrafluoroethylene stirrers with graphene. In this work, graphene was used as the sorbent due to its excellent adsorption capability for aromatic compounds, such as polycyclic aromatic compounds. Graphene was successfully immobilized onto polytetrafluoroethylene-stirrer by a bio-inspired polydopamine functionalization method. The graphene-modified polytetrafluoroethylene-stirrer shows good stability and tolerance to stirring, ultrasonication, strong acidic and basic solutions, and to organic solvents. The multilayer coating was characterized by scanning electronic microscopy and Fourier transform infrared spectroscopy. After the optimization of some experimental conditions, the graphene-modified polytetrafluoroethylene stirrer was used for the stirrer bar sorptive extraction of polycyclic aromatic hydrocarbons, in which the binding between the polycyclic aromatic hydrocarbons and the graphene layer was mainly based on π-π stacking and hydrophobic interactions. The graphene-modified polytetrafluoroethylene-stirrer-based stirrer bar sorptive extraction and high-performance liquid chromatography method was developed for the determination of polycyclic aromatic hydrocarbons with great extraction efficiency, with enrichment factors from 18 to 62. The method has low limits of detection of 1-5 pg/mL, wide linear range (5-100 and 10-200 pg/mL), good linearity (R ≥ 0.9957) and good reproducibility (RSD ≤ 6.45%). The proposed method has been applied to determine polycyclic aromatic hydrocarbons in real dust samples. Good recoveries were obtained, ranging from 88.53 to 109.43%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

PubMed

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

2013-03-01

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.

Provisional Guidance for Quantitative Risk Assessment of Polycyclic Aromatic Hydrocarbons

EPA Science Inventory

Polycyclic Aromatic Hydrocarbons (PAHs) are products of incomplete combustion of organic materials; sources are, thus, widespread,including cigarette smoke, municipal waste incineration, wood stove emissions, coal conversion, energy production form fossil fuels, and automobile an...

Infrared Spectra of Polycyclic Aromatic Hydrocarbons (PAHs)

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Bakes, E. L. O.

2000-01-01

We have computed the synthetic infrared spectra of some polycyclic aromatic hydrocarbons containing up to 54 carbon atoms. The species studied include ovalene, circumcoronene, dicoronylene, and hexabenzocoronene. We report spectra for anions, neutrals, cations, and multiply charged cations.

Amperometric Immunosensors for screening of Polycyclic Aromatic Hydrocarbons in water

NASA Astrophysics Data System (ADS)

Ahmad, A.; Paschero, A.; Moore, E.

2011-08-01

An amperometric immunosensor with low limit detection was developed for the screening of polycyclic aromatic hydrocarbons (PAHs) in water. The system was based on detecting the specific substance using an immunological reaction by measuring the chemical responses to specific antibodies. An integrated biochip with a three electrode system was fabricated. Gold was used as the working electrode with platinum was used as the counter electrode. A modified Ag/AgCl reference electrode was employed to enhance the stability of the immunosensors. Indirect competition enzyme-linked immunosorbent assay (ELISA) was carried out within the electrode using alkaline phosphatase (AP) as the labelled-enzyme. The system shows acceptable reproducibility and good stability. The immunosensor exhibited a wide linear response to PAHs. A limit of detection for this sensor was in the range of 1 to 10 ng ml-1 in aqueous sample.

Synthesis and characterization of a molecularly imprinted polymer for the isolation of the 16 US-EPA priority polycyclic aromatic hydrocarbons (PAHs) in solution.

PubMed

Ncube, Somandla; Kunene, Phumlile; Tavengwa, Nikita T; Tutu, Hlanganani; Richards, Heidi; Cukrowska, Ewa; Chimuka, Luke

2017-09-01

A smart sorbent consisting of benzo[k]fluoranthene-imprinted and indeno[1 2 3-cd]pyrene-imprinted polymers mixed at 1:1 (w/w) was successfully screened from several cavity-tuning experiments and used in the isolation of polycyclic aromatic hydrocarbons from spiked solution. The polymer mixture showed high cross selectivity and affinity towards all the 16 US-EPA priority polycyclic aromatic hydrocarbons. The average extraction efficiency from a cyclohexane solution was 65 ± 13.3% (n = 16, SD). Batch adsorption and kinetic studies confirmed that the binding of polycyclic aromatic hydrocarbons onto the polymer particles resulted in formation of a monolayer and that the binding process was the rate limiting step. The imprinted polymer performance studies confirmed that the synthesized polymer had an imprinting efficiency of 103.9 ± 3.91% (n = 3, SD). A comparison of the theoretical number of cavities and the experimental binding capacity showed that the overall extent of occupation of the imprinted cavities in the presence of excess polycyclic aromatic hydrocarbons was 128 ± 6.45% (n = 3, SD). The loss of selectivity was estimated at 2.9% with every elution cycle indicating that the polymer can be re-used several times with limited loss of selectivity and sensitivity. The polymer combination has shown to be an effective adsorbent that can be used to isolate all the 16 US-EPA priority polycyclic aromatic hydrocarbons in solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Webinar Presentation: Prenatal Exposures to Polycyclic Aromatic Hydrocarbons (PAH) and Childhood Body Mass Index Trajectories

EPA Pesticide Factsheets

This presentation, Prenatal Exposures to Polycyclic Aromatic Hydrocarbons (PAH) and Childhood Body Mass Index Trajectories, was given at the NIEHS/EPA Children's Centers 2015 Webinar Series held on Feb. 11, 2015.

PHOTOTOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS IN COASTAL GREAT LAKES WATERS

EPA Science Inventory

Photoinduced toxicity is the exacerbated toxicity of environmental contaminants by UV radiation. Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) has been well established in the laboratory for numerous aquatic species including larval fish. The contaminants sub-p...

A General Synthetic Route to Polycyclic Aromatic Dicarboximides by Palladium-Catalyzed Annulation Reaction.

PubMed

Shoyama, Kazutaka; Mahl, Magnus; Seifert, Sabine; Würthner, Frank

2018-03-20

Here we report a general method for the synthesis of polycyclic aromatic dicarboximides (PADIs) by palladium-catalyzed annulation of naphthalene dicarboximide to different types of aromatic substrates. Reaction conditions were optimized by systematic variation of ligand, solvent, and additive. It was shown that solvent has a decisive effect on the yield of the reaction products, and thus 1-chloronaphthalene as solvent afforded the highest yield. By applying the optimized reaction conditions, a broad series of planar carbo- and heterocycle containing PADIs were synthesized in up to 97% yield. Moreover, this approach could be applied to curved aromatic scaffold to achieve the respective bowl-shaped PADI. Two-fold annulation was accomplished by employing arene diboronic esters, affording polycyclic aromatic bis(dicarboximides). The optical and electrochemical properties of this broad series of PADIs were explored as well.

ADSORPTION OF POLYCYCLIC AROMATIC HYDROCARBONS IN AGED HARBOR SEDIMENTS

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) are a group of hydrophobic organic contaminants which have low aqueous solubilities and are common pollutants in harbor sediments. Adsorption and desorption isotherms for PAHs are conducted to study the abiotic sorption of PAHs in uncontami...

AGRONOMIC OPTIMIZATION FOR PHYTOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBONS

EPA Science Inventory

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

ASSAYING PARTICLE-BOUND POLYCYCLIC AROMATIC HYDROCARBONS (PAH) FROM ARCHIVED PM2.5 FILTERS

EPA Science Inventory

Airborne particulate matter contains numerous organic species, including several polycyclic aromatic hydrocarbons (PAHs) that are known or suspected carcinogens. Existing methods for measuring airborne PAHs are complex and costly, primarily because they are designed to collect...

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...

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...

MUTAGENICITY IN SALMONELLA OF SULFUR-CONTAINING POLYCYCLIC AROMATIC HETEROCYCLES AND THEIR DIHYDRODIOL DERIVATIVES

EPA Science Inventory

Polycyclic aromatic sulfur heterocycles (PASH) are common constituents of cigarette smoke, fossil fuel-derived materials, and their combustion byproducts. Many PASH are known mutagens and carcinogens. However, unlike their nonsulfur-containing counterparts, relatively little is k...

Analysis of the impregnation of ZnO:Mn2+ nanoparticles on cigarette filters for trapping polycyclic aromatic hydrocarbons (PAHs)

NASA Astrophysics Data System (ADS)

Estrada-Izquierdo, Irma; Sánchez-Espindola, Esther; Uribe-Hernández, Raúl; Ramón-Gallegos, Eva

2012-10-01

Each cigarette can generate 1149 ng of a mixture of 14 polycyclic aromatic hydrocarbons, of which there are a lot of information about its harmful effects on the environment and human health, they are considered mutagenic, teratogenic and carcinogenic. In this paper we tested ZnO:Mn2+ nanoparticles, attached to the filters of cigarettes. The first results showed that the filtration system was able to catch the Benzo(a)pyrene contained in cigarette smoke; but more tests are needed to quantify the efficiency with greater accuracy over other polycyclic aromatic hydrocarbons.

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...

DIGESTIVE BIOAVAILABILITY TO A DEPOSIT FEDDER (ARENICOLA MARINA) OF POLYCYCLIC AROMATIC HYDROCARBONS ASSOCIATED WITH ANTHRPOGENIC PARTICLES

EPA Science Inventory

Marine sediments around urban areas serve as catch basins for anthropogenic particles containing polycyclic aromatic hydrocarbons (PAHs). Using incubations with gut fluids extracted from a deposit-feeding polychaete (Arenicola marina), we determined the digestive bioavailability ...

ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS BY ION TRAP TANDEM MASS SPECTROMETRY

EPA Science Inventory

An ion-trap mass spectrometer with a wave board and tandem mass spectrometry software was used to analyze gas chromatographically separated polycyclic aromatic hydrocarbons (PAHs) by using collision-induced dissociation (CID). The nonresonant (multiple collision) mode was used to...

Susceptibility of eastern oyster early life stages to road surface polycyclic aromatic hydrocarbons (PAHs).

DOT National Transportation Integrated Search

2012-06-01

Polycyclic aromatic hydrocarbons (PAHs) are a class of chemical compounds that are mostly : anthropogenic in nature, and they can become persistent organic contaminants in aquatic : ecosystems. Runoff from impervious surfaces is one of the many ways ...

Identification of persulfate oxidation products of polycyclic aromatic hydrocarbon during remediation of contaminated soil

EPA Science Inventory

The extent of PAH transformation, the formation and transformation of reaction byproducts during persulfate oxidation of polycyclic aromatic hydrocarbons (PAHs) in coking plant soil was investigated. Pre-oxidation analyses indicated that oxygen-containing PAHs (oxy-PAHs) existed ...

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...

Profiling Jet Fuel on Neurotoxic Components With Comprehensive Two-Dimensional GC

DTIC Science & Technology

2007-11-01

nitrogen gas to remove possible contaminants that might interfere in the GCxGC-ToF-MS analysis. The generated JP-8 vapor was lead through the...dimension (min) S ec on d di m en si on (s ) Mono Aromatics Polycyclic Aromatic Hydrocarbons Naphthens Sulfur components Alkanes Figure 14...10.0 20.0 30.0 40.0 50.0 60.0 70.0 First dimension (min) S ec on d di m en si on (s ) Mono Aromatics Polycyclic Aromatic Hydrocarbons Naphthens

Determination of hydroxylated polycyclic aromatic hydrocarbons by HPLC-photoionization tandem mass spectrometry in wood smoke particles and soil samples.

PubMed

Avagyan, Rozanna; Nyström, Robin; Boman, Christoffer; Westerholm, Roger

2015-06-01

A simple and fast method for analysis of hydroxylated polycyclic aromatic hydrocarbons using pressurized liquid extraction and high performance liquid chromatography utilizing photoionization tandem mass spectrometry was developed. Simultaneous separation and determination of nine hydroxylated polycyclic aromatic hydrocarbons and two hydroxy biphenyls could be performed in negative mode with a run time of 12 min, including equilibration in 5 min. The calibration curves were in two concentration ranges; 1-50 ng/mL and 0.01-50 μg/mL, with coefficients of correlation R (2) > 0.997. The limits of detection and method quantification limits were in the range of 9-56 pg and 5-38 ng/g, respectively. A two-level full factorial experimental design was used for screening of conditions with the highest impact on the extraction. The extraction procedure was automated and suitable for a large number of samples. The extraction recoveries ranged from 70 to 102 % and the matrix effects were between 92 and 104 %. The overall method was demonstrated on wood smoke particles and soil samples with good analytical performance, and five OH-PAHs were determined in the concentration range of 0.19-210 μg/g. As far as we know, hydroxylated polycyclic aromatic hydrocarbons were determined in wood smoke and soil samples using photoionization mass spectrometry for the first time in this present study. Accordingly, this study shows that high performance liquid chromatography photoionization tandem mass spectrometry can be a good option for the determination of hydroxylated polycyclic aromatic hydrocarbons in complex environmental samples. Graphical Abstract The method developed in this study was used to determine hydroxylated polycyclic aromatic hydrocarbons in wood smoke and soil.

Fuel quality combustion analysis

NASA Technical Reports Server (NTRS)

Naegeli, D. W.; Moses, C. A.

1979-01-01

A high pressure research combustor operating over a wide range of burner inlet conditions was used to determine the effects of fuel molecular structure on soot formation. Six test fuels with equal hydrogen content (12.8%) were blended to stress different molecular components and final boiling points. The fuels containing high concentrations (20%) of polycyclic aromatics and partially saturated polycyclic structures such as tetralin, produced more soot than would be expected from a hydrogen content correlation for typical petroleum based fuels. Fuels containing naphthenes such as decalin agreed with the hydrogen content correlation. The contribution of polycyclic aromatics to soot formation was equivalent to a reduction in fuel hydrogen content of about one percent. The fuel sensitivity to soot formation due to the polycyclic aromatic contribution decreased as burner inlet pressure and fuel/air ratio increased.

Global and gene-specific promoter methylation changes are related to anti-B[a]PDE-DNA adduct levels and influence micronuclei levels in polycyclic aromatic hydrocarbon-exposed individuals.

PubMed

Pavanello, Sofia; Bollati, Valentina; Pesatori, Angela Cecilia; Kapka, Lucyna; Bolognesi, Claudia; Bertazzi, Pier Alberto; Baccarelli, Andrea

2009-10-01

We investigated the effect of chronic exposure to polycyclic aromatic hydrocarbons (PAHs) on DNA methylation states (percentage of methylated cytosines (%mC)) in Polish male nonsmoking coke-oven workers and matched controls. Methylation states of gene-specific promoters (p53, p16, HIC1 and IL-6) and of Alu and LINE-1 repetitive elements, as surrogate measures of global methylation, were quantified by pyrosequencing in peripheral blood lymphocytes (PBLs). DNA methylation was evaluated in relation to PAH exposure, assessed by urinary 1-pyrenol and anti-benzo[a]pyrene diolepoxide (anti-B[a]PDE)-DNA adduct levels, a critical genetic damage from B[a]P. We also evaluated whether PAH-induced DNA methylation states were in turn associated with micronuclei in PBLs, an indicator of chromosomal instability.

PERSONAL EXPOSURES TO POLYCYCLIC AROMATIC HYDROCARBONS ASSOCIATED WITH THE NHEXAS PILOT

EPA Science Inventory

Personal exposure monitoring for select polycyclic aromatic hydrocarbons (PAHs) was performed as part of the National Human Exposure Assessment Survey (NHEXAS) Pilot Study in Baltimore, MD. Twenty-four hour PM10 sample collections (~5.7 m3) were performed using personal envi...

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...

Webinar Presentation: Exposures to Polycyclic Aromatic Hydrocarbons and Childhood Growth Trajectories and Body Composition: Linkages to Disrupted Self-Regulatory Processes

EPA Pesticide Factsheets

This presentation, Exposures to Polycyclic Aromatic Hydrocarbons and Childhood Growth Trajectories and Body Composition: Linkages to Disrupted Self-Regulatory Processes, was given at the NIEHS/EPA Children's Centers 2016 Webinar Series: Childhood Obesity

Sources and deposition of polycyclic aromatic hydrocarbons to western US national parks

EPA Science Inventory

Seasonal snowpack, lichens, and lake sediment cores were collected from fourteen lake catchments in eight western U.S. National Parks and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs) to determine their current and historical deposition, as well as to identify thei...

Energy sources of polycyclic aromatic hydrocarbons. [Carcinogenicity of PAHs

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

Guerin, M. R.

1977-01-01

Combustion is the predominant end-process by which fossil fuels are converted to energy. Combustion, particularly when inefficient, is also the primary technological source of polycyclic aromatic hydrocarbons (PAHs) released into the environment. The need for liquid fuels to supply the transportation industry and for nonpolluting fuels for heat and power generation provide the incentive to commercialize processes to convert coal to substitute natural gas and oil. These processes represent a potentially massive new source of environmental PAHs. Insuring an adequate supply of energy with minimum impact on the environment and on health is one of the most important, urgent, andmore » challenging goals currently facing science and technology. Polycyclic aromatic hydrocarbon related carcinogenesis is among the most important of possible occupational- and environmental-health impacts of much of the current and projected national energy base. An understanding of the relationship of polycyclic aromatic hydrocarbons (PAHs) to human cancer and a continued surveillance of energy sources for PAH content are necessary to minimize this impact.« less

Polycyclic aromatic hydrocarbons and heavy metals in the Cispata Bay, Colombia: A marine tropical ecosystem.

PubMed

Burgos-Núñez, Saudith; Navarro-Frómeta, Amado; Marrugo-Negrete, José; Enamorado-Montes, Germán; Urango-Cárdenas, Iván

2017-07-15

The concentrations of polycyclic aromatic hydrocarbons and heavy metals were evaluated in shallow sediments, water, fish and seabird samples from the Cispata Bay, Colombia. The heavy metals concentrations in the sediment was in the following order: Cu>Pb>Hg>Cd. The heavy metal concentration was different (p<0.05) in juvenile and adult birds. High concentrations of mercury were registered in the seabird (10.19±4.99mgkg -1 ) and fish (0.67μgg -1 ) samples. The total concentration of polycyclic aromatic hydrocarbons ranged from 7.0-41ngg -1 in sediment, 0.03-0.34ngmL -1 in water samples, 53.24ngg -1 in fish, and 66ngg -1 in seabirds. The high concentrations of heavy metals in seabirds may be explained by their feeding habits. The presence of polycyclic aromatic hydrocarbons in the Cispata Bay may be due to hydrocarbon spills during oil transport at the nearby oil port. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Infrared Spectra of Polycyclic Aromatic Hydrocarbons with Excess Peripheral H Atoms (H(sub n)-PAHs) and their Relation to the 3.4 and 6.9 Micrometer PAH Emission Features

NASA Technical Reports Server (NTRS)

Sandford, Scott A.; Bernstein, Max P.; Materese, Christopher K.

2013-01-01

A population of polycyclic aromatic hydrocarbons (PAHs) and related materials are thought to be responsible for the family of infrared emission features that are seen towards a wide variety of astrophysical environments. A potentially important subclass of these materials are polycyclic aromatic hydrocarbons whose edges contain excess H atoms (H(sub n)-PAHs). While it has been suggested that this type of compound may be present in the interstellar population, it has been difficult to properly assess this possibility because of a lack of suitable infrared laboratory spectra to assist with analysis of the astronomical data. We present the 4000-500 cm(exp -1) (2.5-20 micrometers) infrared spectra of 23 H(sub n)-PAHs and related molecules isolated in argon matrices, under conditions suitable for use in the interpretation of astronomical data. The spectra of molecules with mixed aromatic and aliphatic domains show unique characteristics that distinguish them from their fully aromatic PAH equivalents. We discuss the changes to the spectra of these types of molecules as they transition from fully aromatic to fully aliphatic forms. The implications for the interpretation of astronomical spectra are discussed with specific emphasis on the 3.4 and 6.9 micrometer features. Laboratory data is compared with emission spectra from IRAS 21282+5050, an object with normal PAH emission features, in addition to IRAS 22272+5435 and IRAS 0496+3429, two protoplanetary nebulae with abnormally large 3.4 micrometer features. We show that 'normal' PAH emission objects contain relatively few H(sub n)-PAHs in their emitter populations, but less evolved protoplanetary nebulae may contain significant abundances of these molecules.

FISH BILIARY POLYCYCLIC AROMATIC HYDROCARBON METABOLITES ESTIMATED BY FIXED-WAVELENGTH FLUORESCENCE: COMPARISON WITH HPLC-FLUORESCENT DETECTION

EPA Science Inventory

Fixed wavelength fluorescence (FF) was compared to high-performance liquid chromatography with fluorescence detection (HPLC-F) as an estimation of polycyclic aromatic hydrocarbon (PAH) exposure to fish. Two excitation/emission wavelength pairs were used to measure naphthalene- an...

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 ...

COMPARISON OF IMMUNOASSAY AND GAS CHROMATOGRAPHY/MASS SPECTROMETRY FOR MEASUREMENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN CONTAMINATED SOIL

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) are frequently encountered in the environment and may pose health concerns due to their carcinogenicity. A commercial enzyme-linked immunosorbent assay (ELISA), was evaluated as a screening method for monitoring PAHs at contaminated site...

EFFECT OF IRRADIANCE SPECTRA ON THE PHOTOINDUCED TOXICITY OF THREE POLYCYCLIC AROMATIC HYDROCARBONS

EPA Science Inventory

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 un...

THE EFFECT OF IRRADIANCE SPECTRA ON THE PHOTOACTIVATED TOXICITY OF THREE POLYCYCLIC AROMATIC HYDROCARBONS

EPA Science Inventory

Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) is dependent on the concentration of compounds present and the dose of light recieved. Of the light present, only those wavelengths absorbed by the compound have the potential to initiate the photochemical events un...

Polycyclic aromatic hydrocarbons and volatile organic compounds in biochar and biochar-amended soil: A review

USDA-ARS?s Scientific Manuscript database

Residual pollutants including polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and carbon(aceous) nanoparticles are inevitably generated during the pyrolysis of waste biomass, and remain on the solid co-product called biochar. Such pollutants could have adverse effects on ...

CROSS-INDUCTION OF PYRENE AND PHENANTHRENE IN MYCOBACTERIUM SP. ISOLATED FROM POLYCYCLIC AROMATIC HYDROCARBON CONTAMINATED RIVER SEDIMENTS

EPA Science Inventory

A polycyclic aromatic hydrocarbon (PAH)-degrading culture enriched from contaminated river sediments and a Mycobacterium sp. isolated from the enrichment were tested to investigate the possible synergistic and antagonistic interactions affecting the degradation of pyrene in the p...

Cumulative Exposure Assessment for Trace-Level Polycyclic Aromatic Hydrocarbons (PAHs) using Human Blood and Plasma Analysis

EPA Science Inventory

Humans experience chronic cumulative trace-level exposure to mixtures of volatile, semi-volatile, and non-volatile polycyclic aromatic hydrocarbons (PAHs) present in the environment as by-products of combustion processes. Certain PAHs are known or suspected human carcinogens and ...

Determination of polycyclic aromatic hydrocarbons by four-way parallel factor analysis in presence of humic acid.

PubMed

Yang, Ruifang; Zhao, Nanjing; Xiao, Xue; Yu, Shaohui; Liu, Jianguo; Liu, Wenqing

2016-01-05

There is not effective method to solve the quenching effect of quencher in fluorescence spectra measurement and recognition of polycyclic aromatic hydrocarbons in aquatic environment. In this work, a four-way dataset combined with four-way parallel factor analysis is used to identify and quantify polycyclic aromatic hydrocarbons in the presence of humic acid, a fluorescent quencher and an ubiquitous substance in aquatic system, through modeling the quenching effect of humic acid by decomposing the four-way dataset into four loading matrices corresponding to relative concentration, excitation spectra, emission spectra and fluorescence quantum yield, respectively. It is found that Phenanthrene, pyrene, anthracene and fluorene can be recognized simultaneously with the similarities all above 0.980 between resolved spectra and reference spectra. Moreover, the concentrations of them ranging from 0 to 8μgL(-1) in the test samples prepared with river water could also be predicted successfully with recovery rate of each polycyclic aromatic hydrocarbon between 100% and 120%, which were higher than those of three-way PARAFAC. These results demonstrate that the combination of four-way dataset with four-way parallel factor analysis could be a promising method to recognize the fluorescence spectra of polycyclic aromatic hydrocarbons in the presence of fluorescent quencher from both qualitative and quantitative perspective. Copyright © 2015 Elsevier B.V. All rights reserved.

Application of sunflower stalk-carbon nitride nanosheets as a green sorbent in the solid-phase extraction of polycyclic aromatic hydrocarbons followed by high-performance liquid chromatography.

PubMed

Marzi Khosrowshahi, Elnaz; Razmi, Habib

2018-02-08

A green biocomposite of sunflower stalks and graphitic carbon nitride nanosheets has been applied as a solid-phase extraction adsorbent for sample preparation of five polycyclic aromatic hydrocarbons in different solutions using high-performance liquid chromatography with ultraviolet detection. Before the modification, sunflower stalks exhibited relatively low adsorption to the polycyclic aromatic hydrocarbons extraction. The modified sunflower stalks showed increased adsorption to the analytes extraction due to the increase in surface and existence of a π-π interaction between the analytes and graphitic carbon nitride nanosheets on the surface. Under the optimal conditions, the limits of detection and quantification for five polycyclic aromatic hydrocarbons compounds could reach 0.4-32 and 1.2-95 ng/L, respectively. The method accuracy was evaluated using recovery measurements in spiked real samples and good recoveries from 71 to 115% with relative standard deviations of <10% have been achieved. The developed method was successfully applied for polycyclic aromatic hydrocarbons determination in various samples-well water, tap water, soil, vegetable, and barbequed meat (kebab)-with analytes contents ranging from 0.065 to 13.3 μg/L. The prepared green composite as a new sorbent has some advantages including ease of preparation, low cost, and good reusability. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

PubMed

Kamiński, M; Gilgenast, E; Przyjazny, A; Romanik, G

2006-07-28

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 single peak obtained using normal phase high-performance liquid chromatography (NP-HPLC), a column of the NH2 type, n-heptane as the eluent, refractive index detector (RID) and backflushing of the eluent. However, the methods mentioned above cannot be applied when the fuel contains fatty acid methyl esters (FAME), which lately has become more common. The content of FAME in diesel oils is determined using mid-IR spectrophotometry based on the absorption of carbonyl group. However, no standard procedure for the determination of classes of aromatic hydrocarbons in diesel fuels containing FAME is yet available. The present work describes such a modification of methods EN-12916/ASTM D-6591 that provides a simultaneous determination of individual groups of aromatic hydrocarbons, total content of polycyclic aromatic hydrocarbons and the FAME content in diesel fuels. The refractive index detector (RID) and n-heptane as the mobile phase are still used, but backflushing of the eluent is applied after the elution of all polycyclic aromatic hydrocarbons. Additionally, ultraviolet diode array detection is used for the exact determination of low contents of polycyclic aromatic hydrocarbons and to confirm the presence of FAME in the analyzed fuel.

PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY IN MEDAKA (ORYZIAS LATIPES) EMBRYOS: RELEVANCE TO ENVIRONMENTAL RISK IN CONTAMINATED SITES

EPA Science Inventory

The hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoa...

CYCLOPENTA-FUSED POLYCYCLIC AROMATIC HYDROCARBONS IN STRAIN A/J MOUSE LUNG: DNA ADDUCTS, ONCOGENE MUTATIONS, & TUMORIGENESIS

EPA Science Inventory

Cyclopenta-fused Polycyclic Aromatic Hydrocarbons in Strain AJJ Mouse Lung: DNA Adducts, Oncogene Mutations, and Tumorigenesis.

We have examined the relationships between DNA adducts, Ki-ras oncogene mutations, DNA adducts, and adenoma induction in the lungs of strain A/J...

THE APPLICATION OF COMPUTATIONAL MOLECULAR METHODS TO UNDERSTAND THE HEALTH EFFECTS OF ENVIRONMENTAL CHEMICALS-POLYCYCLIC AROMATIC HYDROCARBONS

EPA Science Inventory

In evaluating the risk posed by chemicals introduced into the environment, information
about their molecular mechanism of action provides a basis for extrapolating from the
laboratory to the environment. Polycyclic aromatic hydrocarbons (PAH) are a large class
of...

POLYCYCLIC AROMATIC HYDROCARBON FORMATION IN OPPOSED FLOW DIFFUSION FLAMES OF ETHANE. (R825412)

EPA Science Inventory

Abstract

The effect of fuel-side carbon density on the levels of polycyclic aromatic hydrocarbon (PAH) formation in atmospheric pressure, opposed flow, ethane diffusion flames has been studied using heated micro-probe sampling and gas chromatography/mass spectrometry (...

IMPORTANCE OF BLACK CARBON IN DISTRIBUTION AND BIOACCUMULATION MODELS OF POLYCYCLIC AROMATIC HYDROCARBONS IN CONTAMINATED MARINE SEDIMENTS

EPA Science Inventory

The roles and relative importance of nonpyrogenic organic carbon (NPOC) and black carbon (BC) as binding phases of polycyclic aromatic hydrocarbons (PAHs) were assessed by their ability to estimate pore water concentrations and biological uptake in various marine sediments. Sedim...

THE PHOTOTOXOICITY OF POLYCYCLIC AROMATIC HYDROCARBONS: A THEORETICAL STUDY OF EXCITED STATES AND CORRELATION TO EXPERIMENT

EPA Science Inventory

Investigators using models to determine the phototoxic effects of sunlight on polycyclic aromatic hydrocarbons (PAHS) have invoked the excited states of the molecule as important in elucidating the mechanism of these reactions. Energies of actual excited states were calcu...

Development of a Relative Potency Factor (Rpf) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (External Review Draft)

EPA Science Inventory

EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of polycyclic aromatic hydrocarbon (PAH) mixtures that when finalized will appear on the Integrated Risk Information System (IRIS) database. ...

Particle in a Disk: A Spectroscopic and Computational Laboratory Exercise Studying the Polycyclic Aromatic Hydrocarbon Corannulene

ERIC Educational Resources Information Center

Frey, E. Ramsey; Sygula, Andrzej; Hammer, Nathan I.

2014-01-01

This laboratory exercise introduces undergraduate chemistry majors to the spectroscopic and theoretical study of the polycyclic aromatic hydrocarbon (PAH), corannulene. Students explore the spectroscopic properties of corannulene using UV-vis and Raman vibrational spectroscopies. They compare their experimental results to simulated vibrational…

SOLAR RADIATION DOSE AND PHOTOTOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS: A CASE STUDY

EPA Science Inventory

The toxicity of polycyclic aromatic hydrocarbons increases by as much as three orders of magnitude in the presence of solar radiation. The risk of this photoactive toxicity is thus based on both tissue concentrations of potentially photo activated compounds and the levels of subs...

TRENDS OF POLYCYCLIC AROMATIC HYDROCARBON LEVELS AND MUTAGENICITY IN SANTIAGO'S INHALABLE AIRBORNE PARTICLES IN THE PERIOD 1992-1996.

EPA Science Inventory

Abstract

Trends of polycyclic aromatic hydrocarbons (PAHs) for 1992-1996 (cold season) and their mutagenic activity were investigated in organic extracts from the Santiago. Chile. inhalable particles (PM10). The highest PAH concentrations were observed in 1992 and decline...

PERSONAL EXPOSURE TO FINE PARTICLE POLYCYCLIC AROMATIC HYDROCARBONS: OUTDOOR SOURCE TRACERS

EPA Science Inventory

The most carcinogenic and toxic polycyclic aromatic hydrocarbons (PAH) are the 4-5 ring PAH found preferentially adsorbed to the fine particles (<2.54u in urban ambient air and personal air. Personal exposure to the carcinogenic particle bound PAH is also highly correlated ...

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...

THE RATES OF POLYCYCLIC AROMATIC HYDROCARBON EMISSIONS FROM INCENSE BURNING

EPA Science Inventory

The paper presents the results of experiments performed to determine the amounts of gas- and particle-phase polycyclic aromatic hydrocarbons (PAHS) in incense smoke. Ten brands of incense, 3 of stick, 2 of joss stick, and one each of cone, smudge bundle, rope, powder, and rock, w...

FORMATION OF POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR GROWTH TO SOOT -A REVIEW OF CHEMICAL REACTION PATHWAYS. (R824970)

EPA Science Inventory

The generation by combustion processes of airborne species of current health concern such as polycyclic aromatic hydrocarbons (PAH) and soot particles necessitates a detailed understanding of chemical reaction pathways responsible for their formation. The present review discus...

75 FR 54628 - Science Advisory Board Staff Office; Notification of a Public Teleconference of the Science...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

... a Public Teleconference of the Science Advisory Board; Polycyclic Aromatic Hydrocarbon (PAH... Hydrocarbon (PAH) Mixtures Review Panel to discuss its draft report on EPA's Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures. DATES: The SAB PAH Mixtures...

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

ERIC Educational Resources Information Center

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

2004-01-01

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.

INFLUENCE OF SOOT CARBON ON THE BIOACCULUMATION OF SEDIMENT-BOUND POLYCYCLIC AROMATIC HYDROCARBONS BY MARINE BENTHIC INVERTEBRATES: AN INTERSPECIES COMPARISON

EPA Science Inventory

The sorption of polycyclic aromatic hydrocarbons (PAHs) to soot carbon in marine sediments has been hypothesized to reduce PAH bioavailability. This hypothesis was tested for eight species of marine benthic invertebrates (four polychaete worms, Clymenella torquata, Nereis virens,...

ROLE OF SOURCE MATRIX IN THE BIOAVAILABILITY OF POLYCYCLIC AROMATIC HYDROCARBONS TO DEPOSIT-FEEDING BENTHIC INVERTEBRATES

EPA Science Inventory

The bioavailability of polycyclic aromatic hydrocarbons (PAHs) to benthic organisms is complicated by the variety of ways that they are introduced to coastal waters (dissolved, as nonaqueous phase liquids, and tightly bound to soot, coal, tire rubber, and eroded shale). In order ...

Polycyclic Aromatic Hydrocarbons in Fine Particulate Matter Emitted from Burning Kerosene, Liquid Petroleum Gas, and Wood Fuels in Household Cookstoves

EPA Science Inventory

This study measured polycyclic aromatic hydrocarbon (PAH) composition in particulate matter emissions from residential cookstoves. A variety of fuel and cookstove combinations were examined, including: (i) liquid petroleum gas (LPG), (ii) kerosene in a wick stove, (iii) wood (10%...

PILOT-SCALE SUBCRITICAL WATER REMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBON- AND PESTICIDE-CONTAMINATED SOIL. (R825394)

EPA Science Inventory

Subcritical water (hot water under enough pressure to maintain the liquid
state) was used to remove polycyclic aromatic hydrocarbons (PAHs) and pesticides
from highly contaminated soils. Laboratory-scale (8 g of soil) experiments were
used to determine conditions f...

Photoenhanced Toxicity of Oil to Larval Fish

EPA Science Inventory

Photoenhanced toxicity is the increase in the toxicity of a chemical in the presence of ultraviolet light (UV), compared to toxicity elicited under conditions of minimal UV. Oil products, weathered oils, combusted oil products, and specific polycyclic aromatic compounds in oil ha...

ANAEROBIC TREATMENT OF SOIL WASH FLUIDS FROM A WOOD PRESERVING SITE

EPA Science Inventory

An integrated system has been developed to remediate sols contaminated with pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons (PAHs). This system involves the coupling of two treatment technologies, soil solvent washing and anaerobic biotreatment of the extract. Specif...

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

PubMed

Iwegbue, Chukwujindu M A

2011-10-01

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 μg 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. © Springer Science+Business Media, LLC 2011

DEPENDENCY OF POLYCHLORINATED BIPHENYL AND POLYCYCLIC AROMATIC HYDROCARBON BIOACCUMULATION IN MYA ARENARIA ON BOTH WATER COLUMN AND SEDIMENT BED CHEMICAL ACTIVITIES

EPA Science Inventory

The bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) by the filter-feeding soft-shell clam Mya arenaria was evaluated at three sites near Boston (MA, USA) by assessing the chemical activities of those hydrophobic organic compounds (H...

REAL-TIME AND INTEGRATED MEASUREMENT OF POTENTIAL HUMAN EXPOSURE TO PARTICLE-BOUND POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) FROM AIRCRAFT EXHAUST

EPA Science Inventory

Real-time monitors and low-volume air samplers were used to measure the potential human exposure to airborne polycyclic aromatic hydrocarbon (PAH) concentrations during various flight-related and ground-support activities of C-130H aircraft at an Air National Guard base. Three...

Role of sooty mold fungi in degradation of polycycllic aromatic hydrocarbons (PAHS) in soil

Treesearch

Venera A. Jouraeva; David L. Johnson; John P. Hassett; David J. Nowak; Natalia A. Shipunova; Dana Barbarossa

2006-01-01

The focus of this research was on elucidation of the role of deciduous tree ecosystems in accumulation of fine-particle-associated polycyclic aromatic hydrocarbons (PAHs) and heavy metals on leaves of deciduous trees. The studied species were Tilia x euchlora (frequently infested by sooty mold fungi) and Pyrus calleryana (...

The Influence of Multiwalled Carbon Nanotubes on Polycyclic Aromatic Hydrocarbon (PAH) Bioavailability and Toxicity to Soil Microbial Communities in Alfalfa Rhizosphere

USDA-ARS?s Scientific Manuscript database

Carbon nanotubes (CNTs) may affect bioavailability and toxicity of organic contaminants due to their adsorption properties. Recent studies have observed the influence of multiwalled carbon nanotubes (MWNTs) on the fate of polycyclic aromatic hydrocarbons (PAHs) and other organic contaminants. Greenh...

Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (Interagency Science Consultation Draft)

EPA Science Inventory

On February 26, 2010, the draft Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures document and the charge to external peer reviewers were released for external peer review and public comment. The draft document and t...

RELATING DAILY SOLAR ULTRAVIOLET RADIATION DOSE IN SALT MARSH-ASSOCIATED ESTUARINE SYSTEMS TO LABORATORY ASSESSMENTS OF PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY

EPA Science Inventory

Estuaries of the southeastern United States not only serve an important nursery function but also are common repositories of polycyclic aromatic hydrocarbons (PAHs) derived from upland activities. Thus, these habitats may be at risk for PAHphototoxicity. To better characterize ...

SEASONAL VARIATION OF THE PARTICLE SIZE DISTRIBUTION OF POLYCYCLIC AROMATIC HYDROCARBONS AND OF MAJOR AEROSOL SPECIES IN CLAREMONT, CALIFORNIA. (R827352C020)

EPA Science Inventory

As part of the Southern California Particle Center and Supersite (SCPCS) activities, we measured, during all seasons, particle size distributions of 12 priority pollutant polycyclic aromatic hydrocarbons (PAHs), concurrently with elemental carbon (EC), organic carbon (OC), sul...

Multi-class, multi-residue analysis of pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers and novel flame retardants....mass spectrometry

USDA-ARS?s Scientific Manuscript database

A multi-class, multi-residue method for the analysis of 13 novel flame retardants, 18 representative pesticides, 14 polychlorinated biphenyl (PCB) congeners, 16 polycyclic aromatic hydrocarbons (PAHs), and 7 polybrominated diphenyl ether (PBDE) congeners in catfish muscle was developed and evaluated...

A COMPUTER DOCKING STUDY OF THE BINDING OF POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR METABOLITES TO THE LIGARD-BINDING DOMAIN OF THE ESTROGEN RECEPTOR

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous, anthropogenic chemicals found in the environment. In the present study, computational methods are used to evaluate their potential estrogenicity and the contribution chemicals in this class make to environmental e...

WHY DOES 5-METHYL CHRYSENE INTERACT WITH DNA LIKE BOTH A PLANAR AND A NON-PLANAR POLYCYCLIC AROMATIC HYDROCARBON? QUANTUM MECHANICAL STUDIES

EPA Science Inventory

Polycyclic aromatic hydrocarbons are a large class of anthropogenic chemicals found in the environment. Some class members are potent animal carcinogens while other similar class members show little carcinogenic activity. When considering a series of in vitro studies of the int...

PHOTO-INDUCED POLYCYCLIC AROMATIC HYDROCARBON TOXIC POTENTIALS OF NEAR SHORE LARVAL FISH HABITAT IN THE GREAT LAKES, USA

EPA Science Inventory

Photo-induced toxicity (PIT) of polycyclic aromatic hydrocarbons (PAH) has been documented in laboratory studies for both invertebrate and vertebrate aquatic organisms. PIT has not been verified in field studies for larval fish to date. Filtered water samples and larval fish were...

COMPARATIVE STUDIES OF THE EFFECT OF POLYCYCLIC AROMATIC HYDROCARBON GEOMETRY ON THE HYDROLYSIS OF DIOL EPOXIDES

EPA Science Inventory

Comparative studies of the effect of polycyclic aromatic hydrocarbon geometry on the hydrolysis of diol epoxides

The interaction of the diol epoxides (DEs) of both planar and non-planar PAHs with water have been examined using quantum mechanical and molecular dynamics. Th...

Determination of polycyclic aromatic hydrocarbons in biochar and biochar amended soil

USDA-ARS?s Scientific Manuscript database

A method for the determination of the 16 USEPA polycyclic aromatic hydrocarbons (PAHs) in biochar and soil amended with biochar was developed. Samples were Soxhlet extracted with acetone:cyclohexane 1:1, and PAHs were analysed by GC-MS after silica gel clean-up. In a comparative study based on reflu...

MEASUREMENT OF HIGH-MOLECULAR-WEIGHT POLYCYCLIC AROMATIC HYDROCARBONS IN SOILS BY PARTICLE BEAM HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) comprise a class of potentially hazardous compounds of concern to the U.S.EPA. The application of particle-beam (PB) liquid chromatography-mass spectrometry (LC-MS) to the measurement of high-molecular-weight PAHs was investigated. Instrume...

IMPACTS OF AGING ON IN VIVO AND IN VITRO MEASUREMENTS OF SOIL-BOUND POLYCYCLIC AROMATIC HYDROCARBON AVAILABILITY

EPA Science Inventory

Ingestion of contaminated soil is an exposure pathway at approximately one-half of the Superfund sites in the United States. This study was designed to evaluate the impacts of aging in soil on the availability of polycyclic aromatic hydrocarbons (PAHs). Two coal tar (CT)-amended ...

Partitioning studies of coal-tar constituents in a two-phase contaminated ground-water system

USGS Publications Warehouse

Rostad, C.E.; Pereira, W.E.; Hult, M.F.

1985-01-01

Organic compounds derived from coal-tar wastes in a contaminated aquifer in St. Louis Park, Minnesota, were identified, and their partition coefficients between the tar phase and aqueous phase were determined and compared with the corresponding n-octanol/water partition coefficients. Coal tar contains numerous polycyclic aromatic compounds, many of which are suspected carcinogens or mutagens. Groundwater contamination by these toxic compounds may pose an environmental health hazard in nearby public water-supply wells. Fluid samples from this aquifer developed two phases upon settling: an upper aqueous phase, and a lower oily-tar phase. After separating the phases, polycyclic aromatic compounds in each phase were isolated using complexation with N-methyl-2-pyrrolidone and identified by fused-silica capillary gas chromatography/mass spectrometry. Thirty-one of the polycyclic aromatic compounds were chosen for further study from four different classes: 12 polycyclic aromatic hydrocarbons, 10 nitrogen heterocycles, 5 sulfur heterocycles, and 4 oxygen heterocycles. Within each compound class, the tar/water partition coefficients of these compounds were reasonably comparable with the respective n-octanol/water partition coefficient.

Preliminary Investigation into Pyrotechnic Chemical Products via Mass Spectrometry Techniques

DTIC Science & Technology

2015-03-11

i m u m ) Py/GC/MS: PVC 11 • Pyrolysis of PVC exclusively yield cyclic hydrocarbons – 24.3% benzyl derivatives and 75.6% polycyclic aromatic ...Determination of EPA’s priority pollutant polycyclic aromatic hydrocarbons in drinking waters by solid phase extraction-HPLC” Bruzzoniti et al., Anal... aromatic hydrocarbons (PAH) – 42.3% hydrocarbons , 53.5% phenols, 4.7% nitrogen-containing O NH OH OH N DISTRIBUTION STATEMENT A. Approved for public

Chemically bonded stationary phases that use synthetic hosts containing aromatic binding clefts: HPLC analysis of nitro-substituted polycyclic aromatic hydrocarbons.

PubMed Central

Zimmerman, S C; Saionz, K W; Zeng, Z

1993-01-01

The synthesis of hosts with improved binding affinities for nitroaromatic guests is described. Association constants for several host-guest complexes were measured in chloroform solution and ranged over three orders of magnitude. Two hosts were covalently linked to silica gel to produce chemically bonded stationary phases for HPLC. The use of these phases for HPLC analysis of nitro-substituted polycyclic aromatic hydrocarbons is discussed. PMID:8433981

Inorganic-organic hybrid coating material for the online in-tube solid-phase microextraction of monohydroxy polycyclic aromatic hydrocarbons in urine.

PubMed

Wang, ShuLing; Xu, Hui

2016-12-01

An inorganic-organic hybrid nanocomposite (zinc oxide/polypyrrole) that represents a novel kind of coating for in-tube solid-phase microextraction is reported. The composite coating was prepared by a facile electrochemical polymerization strategy on the inner surface of a stainless-steel tube. Based on the coated tube, a novel online in-tube solid-phase microextraction with liquid chromatography and mass spectrometry method was developed and applied for the extraction of three monohydroxy polycyclic aromatic hydrocarbons in human urine. The coating displayed good extraction ability toward monohydroxy polycyclic aromatic hydrocarbons. In addition, long lifespan, excellent stability, and good compression resistance were also obtained for the coating. The experimental conditions affecting the extraction were optimized systematically. Under the optimal conditions, the limits of detection and quantification were in the range of 0.039-0.050 and 0.130-0.167 ng/mL, respectively. Good linearity (0.2-100 ng/mL) was obtained with correlation coefficients larger than 0.9967. The repeatability, expressed as relative standard deviation, ranged between 2.5% and 9.4%. The method offered the advantage of process simplicity, rapidity, automation, and sensitivity in the analysis of human urinary monohydroxy polycyclic aromatic hydrocarbons in two different cities of Hubei province. An acceptable recovery of monohydroxy polycyclic aromatic hydrocarbons (64-122%) represented the additional attractive features of the method in real urine analysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Removal of crude oil polycyclic aromatic hydrocarbons via organoclay-microbe-oil interactions.

PubMed

Ugochukwu, Uzochukwu C; Fialips, Claire I

2017-05-01

Clay minerals are quite vital in biogeochemical processes but the effect of organo-clays in the microbial degradation of crude oil polycyclic aromatic hydrocarbons is not well understood. The role of organo-saponite and organo-montmorillonite in comparison with the unmodified clays in crude oil polycyclic aromatic hydrocarbons (PAHs) removal via adsorption and biodegradation was studied by carrying out microcosm experiments in aqueous clay/oil systems with a hydrocarbon degrading microbial community that is predominantly alcanivorax spp. Montmorillonite and saponite samples were treated with didecyldimethylammonium bromide to produce organo-montmorillonite and organo-saponite used in this study. Obtained results indicate that clays with high cation exchange capacity (CEC) such as montmorillonite produced organo-clay (organomontmorillonite) that was not stimulatory to biodegradation of crude oil polycyclic aromatic compounds, especially the low molecular weight (LMW) ones, such as dimethylnaphthalenes. It is suggested that interaction between the organic phase of the organo-clay and the crude oil PAHs which is hydrophobic in nature must have reduced the availability of the polycyclic aromatic hydrocarbons for biodegradation. Organo-saponite did not enhance the microbial degradation of dimethylnaphthalenes but enhanced the biodegradation of some other PAHs such as phenanthrene. The unmodified montmorillonite enhanced the microbial degradation of the PAHs and is most likely to have done so as a result of its high surface area that allows the accumulation of microbes and nutrients enhancing their contact. Copyright © 2017 Elsevier Ltd. All rights reserved.

Photoenhanced toxicity of oil to larval fish - abstract

EPA Science Inventory

Photoenhanced toxicity is the increase in the toxicity of a chemical in the presence of ultraviolet light (UV), compared to toxicity elicited under conditions of minimal UV. A variety of oil products, weathered and chemically dispersed oils, and specific polycyclic aromatic compo...

Photoenhanced Toxicity of Petroleum to Aquatic Invertebrates and Fish

EPA Science Inventory

Photoenhanced toxicity is a distinct mechanism of petroleum toxicity that is mediated by the interaction of solar radiation with specific polycyclic aromatic compounds in oil. Phototoxicity is observed as a twofold to greater than 1000-fold increase in chemical toxicity to aquati...

Determination of oxygen and nitrogen derivatives of polycyclic aromatic hydrocarbons in fractions of asphalt mixtures using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization.

PubMed

Nascimento, Paulo Cicero; Gobo, Luciana Assis; Bohrer, Denise; Carvalho, Leandro Machado; Cravo, Margareth Coutinho; Leite, Leni Figueiredo Mathias

2015-12-01

Liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization was used for the determination of polycyclic aromatic hydrocarbon derivatives, the oxygenated polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons, formed in asphalt fractions. Two different methods have been developed for the determination of five oxygenated and seven nitrated polycyclic aromatic hydrocarbons that are characterized by having two or more condensed aromatic rings and present mutagenic and carcinogenic properties. The parameters of the atmospheric pressure chemical ionization interface were optimized to obtain the highest possible sensitivity for all compounds. The detection limits of the methods ranged from 0.1 to 57.3 μg/L for nitrated and from 0.1 to 6.6 μg/L for oxygenated derivatives. The limits of quantification were in the range of 4.6-191 μg/L for nitrated and 0.3-8.9 μg/L for oxygenated derivatives. The methods were validated against a diesel particulate extract standard reference material (National Institute of Standards and Technology SRM 1975), and the obtained concentrations (two nitrated derivatives) agreed with the certified values. The methods were applied in the analysis of asphalt samples after their fractionation into asphaltenes and maltenes, according to American Society for Testing and Material D4124, where the maltenic fraction was further separated into its basic, acidic, and neutral parts following the method of Green. Only two nitrated derivatives were found in the asphalt sample, quinoline and 2-nitrofluorene, with concentrations of 9.26 and 2146 mg/kg, respectively, whereas no oxygenated derivatives were detected. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING URINE SAMPLES FOR ANALYSIS OF HYDROXY POLYCYCLIC AROMATIC HYDROCARBONS, PENTACHLOROPHENOL AND 2,4-D (SOP-5.21)

EPA Science Inventory

The method for extracting and preparing urine samples for analysis of hydroxy-polycyclic aromatic hydrocarbons, pentachlorophenol and 2,4-D is summarized in this SOP. It covers the extraction, concentration and methylation of samples that are to be analyzed by gas chromatography/...

DIFFUSIVE EXCHANGE OF GASEOUS POLYCYCLIC AROMATIC HYDROCARBONS AND POLYCHLORINATED BIPHENYLS ACROSS THE AIR-WATER INTERFACE OF THE CHESAPEAKE BAY. (R825245)

EPA Science Inventory

Dissolved and gas-phase concentrations of nine polycyclic aromatic hydrocarbons and 46 polychlorinated biphenyl congeners were measured at eight sites on the Chesapeake Bay at four different times of the year to estimate net diffusive air-water gas exchange rates. Gaseous PAHs ar...

MEASURING AIRBORNE PAHS FROM THE NEW YORK WORLD TRADE CENTER DISASTER

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in ambient air, are suspected human carcinogens, and have been linked to genotoxic and mutagenic effects. Although there are no specific monitoring programs for PAHs in ambient air in the United States, there is a national...

Detection and characterization of human serum antibodies to polycyclic aromatic hydrocarbon diol-epoxide DNA adducts.

PubMed Central

Newman, M J; Light, B A; Weston, A; Tollurud, D; Clark, J L; Mann, D L; Blackmon, J P; Harris, C C

1988-01-01

The presence of serum antibodies to the diol-epoxide DNA adducts of representative polycyclic aromatic hydrocarbons (PAH), chrysene, benz[a]anthracene and benzo[a]pyrene, was determined by ELISA using serum samples obtained from normal healthy individuals. Antibodies that reacted against PAH adducted-DNA, but not against PAH-adducted protein, were found in the serum of approximately 40% of the test individuals. Specificity analysis of the antibodies demonstrated that serological cross-reactions between the benzo[a]pyrene and the chrysene diol-epoxide adducts were present. Similar cross-reactivity between the benz[a]anthracene and the chrysene adducts was observed. Sera containing antibodies that were apparently specific for each of the three PAH-DNA adducts were also identified. The presence of antibodies to PAH-DNA adducts indicates both past exposure to these carcinogenic PAH and their metabolic activation to the DNA damaging metabolites. These antibodies may prove to be useful in both retrospective and prospective epidemiological studies of various diseases associated with PAH exposure. PMID:3392204

Draft genome sequence of Mycobacterium rufum JS14(T), a polycyclic-aromatic-hydrocarbon-degrading bacterium from petroleum-contaminated soil in Hawaii.

PubMed

Kwak, Yunyoung; Li, Qing X; Shin, Jae-Ho

2016-01-01

Mycobacterium rufum JS14(T) (=ATCC BAA-1377(T), CIP 109273(T), JCM 16372(T), DSM 45406(T)), a type strain of the species Mycobacterium rufum sp. . belonging to the family Mycobacteriaceae, was isolated from polycyclic aromatic hydrocarbon (PAH)-contaminated soil in Hilo (HI, USA) because it harbors the capability of degrading PAH. Here, we describe the first genome sequence of strain JS14(T), with brief phenotypic characteristics. The genome is composed of 6,176,413 bp with 69.25 % G + C content and contains 5810 protein-coding genes with 54 RNA genes. The genome information on M. rufum JS14(T) will provide a better understanding of the complexity of bacterial catabolic pathways for degradation of specific chemicals.

Optimization of multiwalled carbon nanotubes reinforced hollow-fiber solid-liquid-phase microextraction for the determination of polycyclic aromatic hydrocarbons in environmental water samples using experimental design.

PubMed

Hamedi, Raheleh; Hadjmohammadi, Mohammad Reza

2017-09-01

A novel design of hollow-fiber liquid-phase microextraction containing multiwalled carbon nanotubes as a solid sorbent, which is immobilized in the pore and lumen of hollow fiber by the sol-gel technique, was developed for the pre-concentration and determination of polycyclic aromatic hydrocarbons in environmental water samples. The proposed method utilized both solid- and liquid-phase microextraction media. Parameters that affect the extraction of polycyclic aromatic hydrocarbons were optimized in two successive steps as follows. Firstly, a methodology based on a quarter factorial design was used to choose the significant variables. Then, these significant factors were optimized utilizing central composite design. Under the optimized condition (extraction time = 25 min, amount of multiwalled carbon nanotubes = 78 mg, sample volume = 8 mL, and desorption time = 5 min), the calibration curves showed high linearity (R 2  = 0.99) in the range of 0.01-500 ng/mL and the limits of detection were in the range of 0.007-1.47 ng/mL. The obtained extraction recoveries for 10 ng/mL of polycyclic aromatic hydrocarbons standard solution were in the range of 85-92%. Replicating the experiment under these conditions five times gave relative standard deviations lower than 6%. Finally, the method was successfully applied for pre-concentration and determination of polycyclic aromatic hydrocarbons in environmental water samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

"Super-Reducing" Photocatalysis: Consecutive Energy and Electron Transfers with Polycyclic Aromatic Hydrocarbons.

PubMed

Brasholz, Malte

2017-08-21

Donation welcome: Recent developments in visible-light photocatalysis allow the utilization of increasingly negative reduction potentials. Successive energy and electron transfer with polycyclic aromatic hydrocarbons enables the catalytic formation of strongly reducing arene radical anions, classical stoichiometric reagents for one-electron reduction in organic synthesis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Moss as bio-indicators of human exposure to polycyclic aromatic hydrocarbons in Portland, OR

Treesearch

Geoffrey H. Donovan; Sarah E. Jovan; Demetrios Gatziolis; Vicente J. Monleon

2015-01-01

Polycyclic aromatic hydrocarbons (PAHs) are a class of air pollutants linked to a wide range of adverse health outcomes, including asthma, cancers, cardiovascular disease, and fetal growth impairment. PAHs are emitted by combustion of organic matter (e.g. fossil fuels, plant biomass) and can accumulate in plant and animal tissues over time. Compared to criteria...

LASER DESORPTION-IONIZATION OF POLYCYCLIC AROMATIC HYDROCARBONS FROM GLASS SURFACES WITH ION MOBILITY SPECTROMETRY ANALYSIS. (R826769)

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) were analyzed as adsorbates on borosilicate glass at levels from 40 pg (5.5 pg mm^-2) to 7 g (1 

Coal-tar-based pavement sealcoat, polycyclic aromatic Hydrocarbons (PAHs), and environmental health

USGS Publications Warehouse

Mahler, B.J.; Van Metre, P.C.

2011-01-01

Studies by the U.S. Geological Survey (USGS) have identified coal-tar-based sealcoat-the black, viscous liquid sprayed or painted on asphalt pavement such as parking lots-as a major source of polycyclic aromatic hydrocarbon (PAH) contamination in urban areas for large parts of the Nation. Several PAHs are suspected human carcinogens and are toxic to aquatic life.

Determination of descriptors for polycyclic aromatic hydrocarbons and related compounds by chromatographic methods and liquid-liquid partition in totally organic biphasic systems.

PubMed

Ariyasena, Thiloka C; Poole, Colin F

2014-09-26

Retention factors on several columns and at various temperatures using gas chromatography and from reversed-phase liquid chromatography on a SunFire C18 column with various mobile phase compositions containing acetonitrile, methanol and tetrahydrofuran as strength adjusting solvents are combined with liquid-liquid partition coefficients in totally organic biphasic systems to calculate descriptors for 23 polycyclic aromatic hydrocarbons and eighteen related compounds of environmental interest. The use of a consistent protocol for the above measurements provides descriptors that are more self consistent for the estimation of physicochemical properties (octanol-water, air-octanol, air-water, aqueous solubility, and subcooled liquid vapor pressure). The descriptor in this report tend to have smaller values for the L and E descriptors and random differences in the B and S descriptors compared with literature sources. A simple atom fragment constant model is proposed for the estimation of descriptors from structure for polycyclic aromatic hydrocarbons. The new descriptors show no bias in the prediction of the air-water partition coefficient for polycyclic aromatic hydrocarbons unlike the literature values. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis of polydopamine-functionalized magnetic graphene and carbon nanotubes hybrid nanocomposites as an adsorbent for the fast determination of 16 priority polycyclic aromatic hydrocarbons in aqueous samples.

PubMed

Chen, Kun; Jin, Rongrong; Luo, Chen; Song, Guoxin; Hu, Yaoming; Cheng, Hefa

2018-04-01

A novel adsorbent made of polydopamine-functionalized magnetic graphene and carbon nanotubes hybrid nanocomposite was synthesized and applied to determine 16 priority polycyclic aromatic hydrocarbons by magnetic solid phase extraction in water samples. FTIR spectroscopy, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy consistently indicate that the synthesized adsorbents are made of core-shell nanoparticles well dispersed on the surface of graphene and carbon nanotubes. The major factors affecting the extraction efficiency, including the pH value of samples, the amount of adsorbent, adsorption time and desorption time, type and volume of desorption solvent, were systematically optimized. Under the optimum extraction conditions, a linear response was obtained for polycyclic aromatic hydrocarbons between concentrations of 10 and 500 ng/L with the correlation coefficients ranging from 0.9958 to 0.9989, and the limits of detection (S/N = 3) were between 0.1 and 3.0 ng/L. Satisfactory results were also obtained when applying these magnetic graphene/carbon nanotubes/polydopamine hybrid nanocomposites to detect polycyclic aromatic hydrocarbons in several environmental aqueous samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

UV irradiation of polycyclic aromatic hydrocarbons in ices: production of alcohols, quinones, and ethers

NASA Technical Reports Server (NTRS)

Bernstein, M. P.; Sandford, S. A.; Allamandola, L. J.; Gillette, J. S.; Clemett, S. J.; Zare, R. N.

1999-01-01

Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultraviolet (UV) radiation under astrophysical conditions, and the products were analyzed by infrared spectroscopy and mass spectrometry. Peripheral carbon atoms were oxidized, producing aromatic alcohols, ketones, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account for the interstellar 3.4-micrometer emission feature. These classes of compounds are all present in carbonaceous meteorites. Hydrogen and deuterium atoms exchange readily between the PAHs and the ice, which may explain the deuterium enrichments found in certain meteoritic molecules. This work has important implications for extraterrestrial organics in biogenesis.

LOW TEMPERATURE FORMATION OF NITROGEN-SUBSTITUTED POLYCYCLIC AROMATIC HYDROCARBONS (PANHs)—BARRIERLESS ROUTES TO DIHYDRO(iso)QUINOLINES

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

Parker, Dorian S. N.; Yang, Tao; Dangi, Beni B.

Meteorites contain bio-relevant molecules such as vitamins and nucleobases, which consist of aromatic structures with embedded nitrogen atoms. Questions remain over the chemical mechanisms responsible for the formation of nitrogen-substituted polycyclic aromatic hydrocarbons (PANHs) in extraterrestrial environments. By exploiting single collision conditions, we show that a radical mediated bimolecular collision between pyridyl radicals and 1,3-butadiene in the gas phase forms nitrogen-substituted polycyclic aromatic hydrocarbons (PANHs) 1,4-dihydroquinoline and to a minor amount 1,4-dihydroisoquinoline. The reaction proceeds through the formation of a van der Waals complex, which circumnavigates the entrance barrier implying it can operate at very low kinetic energy and thereforemore » at low temperatures of 10 K as present in cold molecular clouds such as TMC-1. The discovery of facile de facto barrierless exoergic reaction mechanisms leading to PANH formation could play an important role in providing a population of aromatic structures upon which further photo-processing of ice condensates could occur to form nucleobases.« less

Polycyclic Aromatic Hydrocarbons and Astrophysics: The State of the Pah Model and a Possible Tracer of Nitrogen in Carbon-Rich Dust

NASA Technical Reports Server (NTRS)

Hudgins, Douglas M.; Allamandola, Louis J.

2003-01-01

Over the past fifteen years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role aromatic materials play in the interstellar medium (ISM). Twenty years ago, the possible existence of an abundant population of large, carbon-rich molecules in the ISM was unthinkable. Today, the unmistakable spectroscopic signatures of polycyclic aromatic hydrocarbon molecules (PAHs) - shockingly large molecules by the standards of traditional interstellar chemistry - are recognized throughout the Universe. In this paper, we will examine the current state of the interstellar PAH model and its utility as a diagnostic tool to derive insight into the nature of the interstellar PAH population. As an example of this application, we will examine the results of our recent spectroscopic studies of polycyclic aromatic nitrogen heterocycles (PANHs)-PAHs with an atom of nitrogen substituted into the aromatic skeleton-and discuss a possible tracer of such species amongst the interstellar PAH emission bands in the latest observational data.

Analysis of Parent/Nitrated Polycyclic Aromatic Hydrocarbons in Particulate Matter 2.5 Based on Femtosecond Ionization Mass Spectrometry.

PubMed

Itouyama, Noboru; Matsui, Taiki; Yamamoto, Shigekazu; Imasaka, Tomoko; Imasaka, Totaro

2016-02-01

Particulate matter 2.5 (PM2.5), collected from ambient air in Fukuoka City, was analyzed by gas chromatography combined with multiphoton ionization mass spectrometry using an ultraviolet femtosecond laser (267 nm) as the ionization source. Numerous parent polycyclic aromatic hydrocarbons (PPAHs) were observed in a sample extracted from PM2.5, and their concentrations were determined to be in the range from 30 to 190 pg/m(3) for heavy PPAHs. Standard samples of nitrated polycyclic aromatic hydrocarbons (NPAHs) were examined, and the limits of detection were determined to be in the picogram range. The concentration of NPAH adsorbed on PM2.5 in the air was less than 900-1300 pg/m(3). Graphical Abstract ᅟ.

Impact of nitrogen-polycyclic aromatic hydrocarbons on phenanthrene and benzo[a]pyrene mineralisation in soil.

PubMed

Anyanwu, Ihuoma N; Ikpikpini, Ojerime C; Semple, Kirk T

2018-01-01

When aromatic hydrocarbons are present in contaminated soils, they often occur in mixtures. The impact of four different (3-ring) nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs) on 12/14 C-phenanthrene and 12/14 C-benzo[a]pyrene (B[a]P) mineralisation in soil was investigated over a 90 d incubation period. The results revealed that both 12/14 C-phenanthrene and 12/14 C-benzo[a]pyrene showed no significant mineralisation in soils amended with 10mgkg -1 and 100mgkg -1 N-PAHs (p>0.05). However, increases in lag-phases and decreases in the rates and extents of mineralisation were observed, over time. Among the N-PAHs, benzo[h]quinoline impacted 14 C-phenanthrene mineralisation with extended and diauxic lag phases. Furthermore, 12/14 C-B[a]P and 14 C-benzo[a]pyrene-nitrogen-containing polycyclic aromatic hydrocarbons ( 14 C-B[a]P-N-PAHs) amended soils showed extensive lag phases (> 21 d); with some 14 C-B[a]P-N-PAH mineralisation recording <1% in both concentrations (10mgkg -1 and 100mgkg -1 ), over time. This study suggests that the presence of N-PAHs in contaminated soil may impact the microbial degradation of polycyclic aromatic hydrocarbons (PAHs) and the impact was most likely the result of limited success in achieving absolute biodegradation of some PAHs in soil. Copyright © 2017 Elsevier Inc. All rights reserved.

Photoenhanced Toxicity of Petroleum to Aquatic Invertebrates and Fish: Review of State of the Science

EPA Science Inventory

Photoenhanced toxicity is a distinct mechanism of petroleum toxicity that is mediated by the interaction of solar radiation with specific polycyclic aromatic compounds (PACs) in oil. Phototoxicity is observed as a 2 to greater than 1000 fold increase in chemical toxicity to aqua...

Generalised Multiplicative Indices of Polycyclic Aromatic Hydrocarbons and Benzenoid Systems

NASA Astrophysics Data System (ADS)

Kulli, V. R.; Stone, Branden; Wang, Shaohui; Wei, Bing

2017-05-01

Many types of topological indices such as degree-based topological indices, distance-based topological indices, and counting-related topological indices are explored during past recent years. Among degree-based topological indices, Zagreb indices are the oldest one and studied well. In the paper, we define a generalised multiplicative version of these indices and compute exact formulas for Polycyclic Aromatic Hydrocarbons and jagged-rectangle Benzenoid systems.

Electron energy loss spectra of polycyclic aromatic hydrocarbons

NASA Technical Reports Server (NTRS)

Keller, John W.; Coplan, M. A.; Goruganthu, R.

1992-01-01

A survey of the electron energy-loss spectroscopy is reported of gas-phase polycyclic aromatic hydrocarbon (PAH) molecules consisting of up to seven rings where the study is limited to the more thermodynamically stable pericondensed systems. The aim of this work is to obtain absorption profiles (proportional to the oscillator strengths) from the visible to the soft X-ray region near 30 eV.

A thermodynamic analysis of the environmental indicators of natural gas combustion processes

NASA Astrophysics Data System (ADS)

Elsukov, V. K.

2010-07-01

Environmental indicators of the natural gas combustion process are studied using the model of extreme intermediate states developed at the Melent’ev Institute of Power Engineering Systems. Technological factors responsible for generation of polycyclic aromatic hydrocarbons and hydrogen cyanide are revealed. Measures for reducing the amounts of polycyclic aromatic hydrocarbons, hydrogen cyanide, nitrogen oxide, and other pollutants emitted from boilers are developed.

New SERS Substrates For Polycyclic Aromatic Hydrocarbon (PAH) Detection: Towards Quantitative SERS Sensors For Environmental Analysis

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

Peron, O.; Laboratoire de Nanotechnologie et d'instrumentation Optique, Institut Charles Delaunay, FRE 2848, Universite de technologie de Troyes, 12 rue Marie Curie, 10010 Troyes; Rinnert, E.

2010-08-06

In the investigation of chemical pollutions, such as PAHs (Polycyclic Aromatic Hydrocarbons) at low concentration in aqueous medium, surface-enhanced Raman scattering (SERS) stands for an alternative to the inherent low cross-section of normal Raman scattering. Indeed, SERS is a very sensitive spectroscopic technique due to the excitation of the surface plasmon modes of the nanostructured metallic film.

EXPLORING RELATIONSHIPS BETWEEN OUTDOOR AIR PARTICULATE-ASSOCIATED POLYCYCLIC AROMATIC HYDROCARBON AND PM2.5: A CASE STUDY OF BENZO(A)PYRENE IN CALIFORNIA METROPOLITAN REGIONS

EPA Science Inventory

Polycyclic aromatic hydrocarbons (PAHs) and particulate matter (PM) are co-pollutants emitted as by-products of combustion processes. Convincing evidence exists for PAHs as a primary toxic component of fine PM (PM_2.5). Because PM_2.5 is listed by the US EPA a...

A NOVEL METABOLIC ACTIVATION PATHWAY FOR POLYCYCLIC AROMATIC HYDROCARBONS: REACTIVE OXYGEN SPECIES-MEDIATED DNA DAMAGE AND MORPHOLOGICAL CELL TRANSFORMATION IN MOUSE EMBRYO CELLS BY K-REGION DIOL METABOLITES

EPA Science Inventory

Benzo[ a ]pyrene (BP) is a well-studied polycyclic aromatic hydrocarbon (P AH) .Many
mechanisms have been suggested to explain its carcinogenic activity, yet many questions still
remain. K-region dihydrodiols (diols) ofPAHs are common metabolites and some are genotoxic. W...

Combined effects of prenatal polycyclic aromatic hydrocarbons and material hardship on child IQ.

PubMed

Vishnevetsky, Julia; Tang, Deliang; Chang, Hsin-Wen; Roen, Emily L; Wang, Ya; Rauh, Virginia; Wang, Shuang; Miller, Rachel L; Herbstman, Julie; Perera, Frederica P

2015-01-01

Polycyclic aromatic hydrocarbons are common carcinogenic and neurotoxic urban air pollutants. Toxic exposures, including air pollution, are disproportionately high in communities of color and frequently co-occur with chronic economic deprivation. We examined whether the association between child IQ and prenatal exposure to polycyclic aromatic hydrocarbons differed between groups of children whose mothers reported high vs. low material hardship during their pregnancy and through child age 5. We tested statistical interactions between hardships and polycyclic aromatic hydrocarbons, as measured by DNA adducts in cord blood, to determine whether material hardship exacerbated the association between adducts and IQ scores. Prospective cohort. Participants were recruited from 1998 to 2006 and followed from gestation through age 7 years. Urban community (New York City) A community-based sample of 276 minority urban youth EXPOSURE MEASURE: Polycyclic aromatic hydrocarbon-DNA adducts in cord blood as an individual biomarker of prenatal polycyclic aromatic hydrocarbon exposure. Maternal material hardship self-reported prenatally and at multiple timepoints through early childhood. Child IQ at 7 years assessed using the Wechsler Intelligence Scale for Children. Significant inverse effects of high cord PAH-DNA adducts on full scale IQ, perceptual reasoning and working memory scores were observed in the groups whose mothers reported a high level of material hardship during pregnancy or recurring high hardship into the child's early years, and not in those without reported high hardship. Significant interactions were observed between high cord adducts and prenatal hardship on working memory scores (β = -8.07, 95% CI (-14.48, -1.66)) and between high cord adducts and recurrent material hardship (β = -9.82, 95% CI (-16.22, -3.42)). The findings add to other evidence that socioeconomic disadvantage can increase the adverse effects of toxic physical "stressors" like air pollutants. Observed associations between high cord adducts and reduced IQ were significant only among the group of children whose mothers reported high material hardship. These results indicate the need for a multifaceted approach to prevention. Copyright © 2015 Elsevier Inc. All rights reserved.

Contaminated sediments from tributaries of the Great Lakes: Chemical characterization and carcinogenic effects in medaka (Oryzias latipes)

USGS Publications Warehouse

Besser, John M.; Schmitt, Christopher J.; Harshbarger, John C.; Peterman, Paul H.; Lebo, Jon A.

1991-01-01

Sediments from four inshore industrial sites and a reference site in the Great Lakes were extracted with organic solvents to produce a crude extract, which was separated on alumina into two fractions: predominantly polycyclic aromatic hydrocarbons; and predominantly nitrogencontaining polycyclic aromatic compounds. Crude extracts were redissolved in acetone and analyzed by gas chromatography and gas chromatography-mass spectrometry. The acetone-redissolved crude extracts from the four industrialized sites contained 5.6–313.3 μg total polycyclic aromatic compounds/g sediment and 3.0–36.4 μg other compounds/g sediment. In addition to the typical EPA priority pollutants, a substantial amount (228.7 μg/g sediment) of alkyl-polycyclic-aromatic compounds was detected in sediments from one of the industrialized sites. Extracts from the reference site contained 1.55 μg total polycyclic aromatic compounds/ g sediment. Medaka (Oryzias latipes) were exposed to multiple pulse doses of acetone-redissolved extracts and fractions. Medaka were also exposed to a known carcinogen, methylazoxymethanol acetate, to verify that chemicals produced tumors in the test fish. Acetone-redissolved extracts and fractions from contaminated sediments were toxic to medaka. Fin erosion and non-neoplastic liver abnormalities were more prevalent in medaka after exposure to acetoneredissolved extracts and fractions from contaminated sediments. Neoplasms previously associated with chemical exposure in wild fishes were induced in medaka exposed to acetone-redissolved extracts and fractions from two of the contaminated sites, but not from the reference site or controls. These findings further support the hypothesis that chemical contaminants in sediments are involved in epizootics of neoplasms in wild fishes at contaminated sites.

Evaluating the aquatic toxicity of complex organic chemical mixtures: lessons learned from polycyclic aromatic hydrocarbon and petroleum hydrocarbon case studies.

PubMed

Landrum, Peter F; Chapman, Peter M; Neff, Jerry; Page, David S

2012-04-01

Experimental designs for evaluating complex mixture toxicity in aquatic environments can be highly variable and, if not appropriate, can produce and have produced data that are difficult or impossible to interpret accurately. We build on and synthesize recent critical reviews of mixture toxicity using lessons learned from 4 case studies, ranging from binary to more complex mixtures of primarily polycyclic aromatic hydrocarbons and petroleum hydrocarbons, to provide guidance for evaluating the aquatic toxicity of complex mixtures of organic chemicals. Two fundamental requirements include establishing a dose-response relationship and determining the causative agent (or agents) of any observed toxicity. Meeting these 2 requirements involves ensuring appropriate exposure conditions and measurement endpoints, considering modifying factors (e.g., test conditions, test organism life stages and feeding behavior, chemical transformations, mixture dilutions, sorbing phases), and correctly interpreting dose-response relationships. Specific recommendations are provided. Copyright © 2011 SETAC.

Airborne Dioxins, Furans and Polycyclic Aromatic Hydrocarbons Exposure to Military Personnel in Iraq

PubMed Central

Masiol, Mauro; Mallon, Timothy; Haines, Kevin M.; Utell, Mark J.; Hopke, Philip K.

2016-01-01

Objectives The objective was to use ambient polycyclic aromatic hydrocarbon (PAH), polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) concentrations measured at Joint Base Balad in Iraq in 2007 to identify the sources of these species and their spatial patterns. Methods The ratios of the measured species were compared to literature data for likely emission sources. Using the multiple site measurements on specific days, contour maps have been drawn using inverse distance weighting (IDW). Results These analyses suggest multiple sources including the burn pit (primarily a source of PCDD/PCDFs), the transportation field (primarily as source of PAHs) and other sources of PAHs that include aircraft, space heating, and diesel power generation. Conclusions The nature and locations of the sources were identified. PCDD/PCDFs were emitted by the burn pit. Multiple PAH sources exist across the base. PMID:27501100

Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall.

PubMed

Zhang, Wei; Zhang, Shucai; Wan, Chao; Yue, Dapan; Ye, Youbin; Wang, Xuejun

2008-06-01

Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing.

Does the concept of Clar's aromatic sextet work for dicationic forms of polycyclic aromatic hydrocarbons?--testing the model against charged systems in singlet and triplet states.

PubMed

Dominikowska, Justyna; Palusiak, Marcin

2011-07-07

The concept of Clar's π-electron aromatic sextet was tested against a set of polycyclic aromatic hydrocarbons in neutral and doubly charged forms. Systems containing different types of rings (in the context of Clar's concept) were chosen, including benzene, naphthalene, anthracene, phenanthrene and triphenylene. In the case of dicationic structures both singlet and triplet states were considered. It was found that for singlet state dicationic structures the concept of aromatic sextet could be applied and the local aromaticity could be discussed in the context of that model, whereas in the case of triplet state dicationic structures Clar's model rather failed. Different aromaticity indices based on various properties of molecular systems were applied for the purpose of the studies. The discussion about the interdependence between the values of different aromaticity indices applied to neutral and charged systems in singlet and triplet states is also included. This journal is © the Owner Societies 2011

Oxidation of polycyclic aromatic hydrocarbons under sulfate-reducing conditions

USGS Publications Warehouse

Coates, J.D.; Anderson, R.T.; Lovley, D.R.

1996-01-01

[14C]naphthalene and phenanthrene were oxidized to 14CO2 without a detectable lag under strict anaerobic conditions in sediments from San Diego Bay, San Diego, Calif., that were heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) but not in less contaminated sediments. Sulfate reduction was necessary for PAH oxidation. These results suggest that the self-purification capacity of PAH-contaminated sulfate-reducing environments may be greater than previously recognized.

Synthesis of g-C3N4/Fe3O4 nanocomposites and application as a new sorbent for solid phase extraction of polycyclic aromatic hydrocarbons in water samples.

PubMed

Wang, Man; Cui, Shihai; Yang, Xiaodi; Bi, Wentao

2015-01-01

An easy preparation of g-C3N4/Fe3O4 nanocomposites by chemical co-precipitation has been demonstrated. The as-prepared materials were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. The high affinity of g-C3N4 toward polycyclic aromatic hydrocarbons and the magnetic behavior of Fe3O4 were combined to provide an efficient and simple magnetic solid phase extraction (MSPE). The adsorption and desorption of polycyclic aromatic hydrocarbons on g-C3N4/Fe3O4 were examined. Different factors affecting the magnetic solid phase extraction of polycyclic aromatic hydrocarbons were assessed in terms of adsorption, desorption, and recovery. Under the optimized conditions, the proposed method showed good limits of detection (LOD, S/N=3) in the range of 0.05-0.1 ng mL(-1) and precision in the range of 1.8-5.3% (RSDs, n=3). This method was also successfully applied to the analysis of real water samples; good spiked recoveries over the range of 80.0-99.8% were obtained. Copyright © 2014 Elsevier B.V. All rights reserved.

Polyaniline-coated cigarette filters as a solid-phase extraction sorbent for the extraction and enrichment of polycyclic aromatic hydrocarbon in water samples.

PubMed

Bunkoed, Opas; Rueankaew, Thanaschaphorn; Nurerk, Piyaluk; Kanatharana, Proespichaya

2016-06-01

Polyaniline coated cigarette filters were successfully synthesized and used as a solid-phase extraction sorbent for the extraction and preconcentration of polycyclic aromatic hydrocarbons in water samples. The polyaniline helped to enhance the adsorption ability of polycyclic aromatic hydrocarbons on the sorbent through π-π interactions. The high porosity and large surface area of the cigarette filters helped to reduce backpressure and can be operated with high sample flow rate without loss of extraction efficiency. The developed sorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The parameters that affected the extraction efficiencies, i.e. polymerization time, type of desorption solvent and its volume, sample flow rate, sample volume, sample pH, ionic strength, and organic modifier were investigated. Under the optimal conditions, the method was linear over the range of 0.5-10 μg/L and a detection limit of 0.5 ng/L. This simple, rapid, and cost-effective method was successfully applied to the preconcentration of polycyclic aromatic hydrocarbons from water samples. The developed method provided a high enrichment factor with good extraction efficiency (85-98%) and a relative standard deviation <10%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Glutathione S-transferase-encoding gene as a potential probe for environmental bacterial isolates capable of degrading polycyclic aromatic hydrocarbons.

PubMed Central

Lloyd-Jones, G; Lau, P C

1997-01-01

Homologs of the glutathione S-transferase (GST)-encoding gene were identified in a collection of aromatic hydrocarbon-degrading Sphingomonas spp. isolated from New Zealand, Antarctica, and the United States by using PCR primers designed from the GST-encoding gene of Sphingomonas paucimobilis EPA505. Sequence analysis of PCR fragments generated from these isolates and of the GST gene amplified from DNA extracted from polycyclic aromatic hydrocarbon (PAH)-contaminated soil revealed a high degree of conservation, which may make the GST-encoding gene a potentially useful marker for PAH-degrading bacteria. PMID:9251217

Biotransformation and induction: implications for toxicity, bioaccumulation and monitoring of environmental xenobiotics in fish.

PubMed Central

Kleinow, K M; Melancon, M J; Lech, J J

1987-01-01

Biotransformation of xenobiotics in fish occurs by many of the same reactions as in mammals. These reactions have been shown to affect the bioaccumulation, persistence, residue dynamics, and toxicity of select chemicals in fish. P-450-dependent monooxygenase activity of fish can be induced by polycyclic aromatic hydrocarbons, but phenobarbital-type agents induce poorly, if at all. Fish monooxygenase activity exhibits ideal temperature compensation and sex-related variation. Induction of monooxygenase activity by polycyclic aromatic hydrocarbons can result in qualitative as well as quantitative changes in the metabolic profile of a chemical. Induction can also alter toxicity. In addition, multiple P-450 isozymes have been described for several fish species. The biotransformation products of certain chemicals have been related to specific P-450 isozymes, and the formation of these products can be influenced by induction. Exposure of fish to low levels of certain environmental contaminants has resulted in induction of specific monooxygenase activities and monitoring of such activities has been suggested as a means of identifying areas of pollutant exposure in the wild. PMID:3297653

Biomonitoring of polycyclic aromatic compounds in the urine of mining workers occupationally exposed to diesel exhaust.

PubMed

Seidel, Albrecht; Dahmann, Dirk; Krekeler, Horst; Jacob, Juergen

2002-02-01

Diesel exhaust is considered a probable human carcinogen by the IARC. Biomonitoring of workers occupationally exposed to diesel exhaust was performed to determine their internal burden of diesel associated aromatic compounds. Personal air sampling also allowed to determine the exposure of the miners at their work place towards several polycyclic aromatic hydrocarbons (PAH) and nitro-arenes, the latter of which are thought to be specific constituents of diesel exhaust. For biomonitoring the urine of 18 underground salt miners was collected during and after their shift for 24-hours. half of the 18 miners were smokers. The urinary levels of 1-hydroxypyrene and hydroxylated phenanthrene metabolites were determined as biomarkers of PAH exposure, whereas urinary levels of some aromatic amines were chosen to monitor exposure towards specific nitro-arenes from diesel exhaust like 1-nitropyrene and 3-nitrobenzanthrone and to monitor the human burden by these compounds from inhaled cigarette smoke. Non-smoking workers exposed to diesel exhaust excrete an average level of about 4 micrograms phenanthrene metabolites, whereas the urinary levels in smokers were up to 3-fold higher. In summary the results indicate that (i) diesel exposure led to an increase of PAH metabolism in the workers examined, most probably by an induction of cytochrome P450 (ii) smokers could be identified in accordance with earlier studies by their increased ratio of phenanthrene metabolites derived from 1,2- and 3,4-oxidation and their higher amounts of excreted 1-naphthylamine, and (iii) the excreted amounts of aromatic amines found as metabolites of the nitro-arenes were about 5- to 10-fold higher as one might expect from the levels determined by personal air sampling at the workplace of the individuals.

Polycyclic aromatic hydrocarbons in some grounded coffee brands.

PubMed

Grover, Inderpreet Singh; Sharma, Rashmi; Singh, Satnam; Pal, Bonamali

2013-08-01

Potentially toxic 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in four brands of grounded coffee. Four to 13 PAHs were detected. Concentrations of total PAHs in different brands of coffee samples were in the range of 831.7-1,589.7 μg/kg. Benzo[a]pyrene (2A: probable human carcinogen) was found in Nescafe Premium whereas naphthalene (2B: possible human carcinogen) was found in all the samples of coffee.

Observational aspects of polycyclic aromatic hydrocarbon charging in the Interstellar Medium

NASA Technical Reports Server (NTRS)

Bakes, E. L. O.; Tielens, Alexander G. G. M.

1995-01-01

We have investigated the charging processes which affect small carbonaceous dust grains and polycyclic aromatic hydrocarbons (PAH's). Because of their high abundance, interstellar PAH molecules can dominate the charge balance of the interstellar medium (ISM), which controls the heating and cooling interstellar gas and interstellar chemistry. We present the results of our model, which compare well with observations and suggest further applications to both laboratory measurements and data obtainable from the KAO.

Water-Sediment Partition of Polycyclic Aromatic Hydrocarbons (PAHs) in Nansi Lake

NASA Astrophysics Data System (ADS)

Zhang, Guizhai; Diao, Youjiang

2018-06-01

Based on field data of polycyclic aromatic hydrocarbons (PAHs) in water and sediment in Nansi Lake. The concentrations and the partitioning characteristic of PAHs in the water and sediment were studied. The lgKd of high molecular weight PAHs were higher than the low molecular weight PAHs. The most of PAHs Kd values were negligible correlated with TOC, soluble salt, clay and pH of the sediment in Nansi Lake.

Polycyclic aromatic hydrocarbons in soils and crops after irrigation of wastewater discharged from domestic sewage treatment plants.

PubMed

Chung, N J; Cho, J Y; Park, S W; Park, B J; Hwang, S A; Park, T I

2008-08-01

The effects of domestic wastewater application on the translocation and accumulation of polycyclic aromatic hydrocarbons (PAHs) in soil and crops (rice, lettuce, and barley) were investigated by Wagner's pot experiment. In the soils and crops after domestic wastewater irrigation, high-molecular weight PAHs (5 to 6 ring) were not detected, but low-molecular weight PAHs (3 to 4 ring) were only detected at trace levels.

Monitoring of vapor phase polycyclic aromatic hydrocarbons

DOEpatents

Vo-Dinh, Tuan; Hajaligol, Mohammad R.

2004-06-01

An apparatus for monitoring vapor phase polycyclic aromatic hydrocarbons in a high-temperature environment has an excitation source producing electromagnetic radiation, an optical path having an optical probe optically communicating the electromagnetic radiation received at a proximal end to a distal end, a spectrometer or polychromator, a detector, and a positioner coupled to the first optical path. The positioner can slidably move the distal end of the optical probe to maintain the distal end position with respect to an area of a material undergoing combustion. The emitted wavelength can be directed to a detector in a single optical probe 180.degree. backscattered configuration, in a dual optical probe 180.degree. backscattered configuration or in a dual optical probe 90.degree. side scattered configuration. The apparatus can be used to monitor an emitted wavelength of energy from a polycyclic aromatic hydrocarbon as it fluoresces in a high temperature environment.

Direct photolysis of polycyclic aromatic hydrocarbons in drinking water sources.

PubMed

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

2011-09-15

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 1500 mJ/cm(2), anthracene and benzo(a)pyrene were efficiently degraded, with much higher percent removals obtained when present in groundwater (83-93%) compared to surface water (36-48%). The removal percentages obtained for fluoranthene were lower and ranged from 13 to 54% in the different water matrices tested. Several parameters that influence the direct photolysis of polycyclic aromatic hydrocarbons were determined and their photolysis by-products were identified by mass spectrometry. The formation of photolysis by-products was found to be highly dependent on the source waters tested. Copyright © 2011 Elsevier B.V. All rights reserved.

Absolute fragmentation cross sections in atom-molecule collisions: Scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules

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

Chen, T.; Gatchell, M.; Stockett, M. H.

2014-06-14

We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH{sup +}) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections (including statistical fragmentation) for 110 eV PAH/PAH{sup +} + He collisions, and show that they compare well with experimental results. We demonstrate that non-statistical fragmentation becomes dominant for large PAHs and that it yields highly reactive fragments forming strong covalent bonds with atoms (H and N) and molecules (C{sub 6}H{sub 5}). Thus nonstatistical fragmentation may be an effectivemore » initial step in the formation of, e.g., Polycyclic Aromatic Nitrogen Heterocycles (PANHs). This relates to recent discussions on the evolution of PAHNs in space and the reactivities of defect graphene structures.« less

Ingredients for Life (Artist's Concept)

NASA Technical Reports Server (NTRS)

2005-01-01

[figure removed for brevity, see original site] Figure 1: Artist's Conception Symbolically Represents Complex Organic Molecules

This artist's conception symbolically represents complex organic molecules, known as polycyclic aromatic hydrocarbons, seen in the early universe. These large molecules, comprised of carbon and hydrogen, are considered among the building blocks of life.

NASA's Spitzer Space Telescope is the first telescope to see polycyclic aromatic hydrocarbons so early -- 10 billion years further back in time than seen previously. Spitzer detected these molecules in galaxies when our universe was one-fourth of its current age of about 14 billion years.

These complex molecules are very common on Earth. They form any time carbon-based materials are not burned completely. They can be found in sooty exhaust from cars and airplanes, and in charcoal broiled hamburgers and burnt toast.

Polycyclic aromatic hydrocarbons are pervasive in galaxies like our own Milky Way, and play a significant role in star and planet formation.

Renal cancer risk and occupational exposure to polycyclic aromatic hydrocarbons and plastics

PubMed Central

Karami, Sara; Boffetta, Paolo; Brennan, Paul; Stewart, Patricia A.; Zaridze, David; Matveev, Vsevolod; Janout, Vladimir; Kollarova, Helena; Bencko, Vladimir; Navratilova, Marie; Szeszenia-Dabrowska, Neonila; Mates, Dana; Gromiec, Jan P.; Sobotka, Roman; Chow, Wong-Ho; Rothman, Nathaniel; Moore, Lee E.

2011-01-01

Objective To investigate whether occupational exposure to polycyclic aromatic hydrocarbons and certain plastic monomers increased renal cell carcinomas (RCC) risk. Methods Unconditional logistic regression was used to calculate RCC risk in relation to exposure. Results No association between RCC risk and having ever been occupationally exposed to any polycyclic aromatic hydrocarbons or plastics was observed. Duration of exposure and average exposure also showed no association with risk. Suggestive positive associations between RCC risk and cumulative exposure to styrene (P-trend = 0.02) and acrylonitrile (P-trend = 0.06) were found. Cumulative exposure to petroleum/gasoline engine emissions was inversely associated with risk (P-trend = 0.02). Conclusions Results indicate a possible association between occupational styrene and acrylonitrile exposure and RCC risk. Additional studies are needed to replicate findings, as this is the first time these associations have been reported and they may be due to chance. PMID:21270648

PRESSURE EFFECTS IN POLYCYCLIC AROMATIC NITROGENATED HETEROCYCLES (PANHs): DIAGNOSTIC QUALITIES AND COSMOBAROMETRY POTENTIAL

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

Montgomery, Wren; Sephton, Mark A., E-mail: w.montgomery@imperial.ac.uk

2016-03-01

The influence of polycyclic aromatic nitrogen heterocycles (PANHs), which have been suggested as contributors to the interstellar IR emission bands, on interstellar emission features is difficult to constrain because their infrared characteristics are strongly similar to those for polycyclic aromatic hydrocarbons (PAHs). One possible solution is to seek a means of visualizing the presence of PANHs that provides information that is distinct from that for PAHs. Although PANHs and PAHs have similar infrared characteristics in many settings, this relationship may not be universally maintained. We have used in situ high-pressure synchrotron-source Fourier transform infrared spectroscopy to determine that the responsesmore » of two representative molecules, acridine and anthracene, differ at high pressures (>ca. 1 GPa). Because there are a number of high-pressure environments that can be remotely observed by infrared spectroscopy, they represent a potential to glimpse the distribution of PANHs across the cosmos.« less

Influence of silicon defects on the adsorption of thiophene-like compounds on polycyclic aromatic hydrocarbons: a theoretical study using thiophene + coronene as the simplest model.

PubMed

Galano, Annia

2007-03-08

Physisorption and chemisorption processes of thiophene on coronene and 2Si-coronene have been studied using density functional theory and MP2 methods. These systems have been chosen as the simplest models to describe the adsorption of thiophene-like compounds on polycyclic aromatic hydrocarbons (PAHs). The calculated data suggest that the presence of silicon atoms in PAHs could favor their interaction with thiophene and similar compounds. Small stabilization energies have been found for several physisorbed complexes. The thiophene chemisorption on coronene seems very unlikely to occur, while that on 2Si-coronene leads to addition products which are very stable, with respect to the isolated reactants. These chemisorption processes were found to be exoergic (DeltaG < 0) in the gas phase and in the nonpolar liquid phase. The results reported in this work suggest that silicon defects on extended polycyclic aromatic hydrocarbons, such as graphite, soot, and large-diameter carbon nanotubes, could make them useful in the removal processes of aromatic sulfur compounds from oil hydrocarbons.

Analyses at High Spatial Resolution of Organic Molecules in Extraterrestrial Samples: Two-Step Laser Mass Spectrometry: Search for Polycyclic Aromatic Hydrocarbons in Antarctic Meteorite and Micrometeorite Samples

NASA Technical Reports Server (NTRS)

Zare, Richard N.

1998-01-01

Perhaps the best way to summarize the past three-year grant period is to cite the publications and present a brief synopsis of each: 1. "Indigenous Polycyclic Aromatic Hydrocarbon Molecules in Circumstellar Graphite Grains." Bulk C-12/C-13 isotope ratios observed in some graphite grains extracted from primitive meteorites point strongly to a circumstellar origin. By applying our technique of microprobe two-step laser desorption laser ionization mass spectrometry ((mu)L(sup 2)MS) to individual circumstellar graphite grains we have measured the C-12/C-13 isotope ratio of various polycyclic aromatic hydrocarbons (PAHS) found in these grains. 2. "Deuterium Enrichments in Cluster IDPS," Large enrichments in the D/H isotope ratios in IDPs likely arise from the preservation of presolar molecules. 3. "Evidence for thermalization of surface-disorder molecules at heating rates of 10(exp 8) K/s". A careful study of the ((mu)L(sup 2)MS) of aniline-d(sub 7) from a single-crystal surface (0001) of sapphire (al2O3) shows that all measured properties are consistent with a thermal mechanism for desorption. 4. "Search for past life on Mars; possible relic biogenic activity in Martian meteorite ALH 84001. The authors examined the Martian meteorite ALH 84001 and found several lines of evidence compatible with existence of past primitive (single-cell) life on early Mars. 5. "Microprobe two-step laser mass spectrometry as an analytical tool for meteorite samples". THis paper presents a comprehensive review of (mu)L(sup 2)MS and how this technique can be applied to meteoritic samples. 6. "Indigenous polycyclic aromatic hydrocarbons in circumstellar graphite grains from primitive meteorites". The C-12/C-13 isotope ratios were measured for PAHs in a total of 89 spherical graphite grains. 7. "Observation of indigenous polycyclic aromatic hydrocarbons in "Giant" carbonaceous antarctic micrometeorites." The (mu)L(sup 2)MS method was used to establish the nature and distribution of PAHs in fragments of fifteen (approx. 200 microns) carbonaceous antarctic micrometeorites (AMMs). 8. "Evidence for the extraterrestrial origin of polycyclic aromatic hydrocarbons in the Martian meteorite ALH 84001" We have undertaken additional contamination studies of ALH 84001.

Effect of ZSM-5 acidity on aromatic product selectivity during upgrading of pine pyrolysis vapors

DOE PAGES

Engtrakul, Chaiwat; Mukarakate, Calvin; Starace, Anne K.; ...

2015-11-14

The impact of catalyst acidity on the selectivity of upgraded biomass pyrolysis products was studied by passing pine pyrolysis vapors over five ZSM-5 catalysts of varying acidity at 500 degrees C. The SiO 2-to-Al 2O 3 ratio (SAR) of the ZSM-5 zeolite was varied from 23 to 280 to control the acidity of the catalyst and the composition of upgraded products. The upgraded product stream was analyzed by GCMS. Additionally, catalysts were characterized using temperature programmed desorption, diffuse-reflectance FTIR spectroscopy, N 2 physisorption, and X-ray diffraction. The results showed that the biomass pyrolysis vapors were highly deoxygenated to form amore » slate of aromatic hydrocarbons over all of the tested ZSM-5 catalysts. As the overall acidity of the ZSM-5 increased the selectivity toward alkylated (substituted) aromatics (e.g., xylene, dimethyl-naphthalene, and methyl-anthracene) decreased while the selectivity toward unsubstituted aromatics (e.g., benzene, naphthalene, and anthracene) increased. Additionally, the selectivity toward polycyclic aromatic compounds (2-ring and 3-ring) increased as catalyst acidity increased, corresponding to a decrease in acid site spacing. The increased selectivity toward less substituted polycyclic aromatic compounds with increasing acidity is related to the relative rates of cyclization and alkylation reactions within the zeolite structure. As the acid site concentration increases and sites become closer to each other, the formation of additional cyclization products occurs at a greater rate than alkylated products. The ability to adjust product selectivity within 1-, 2-, and 3-ring aromatic families, as well as the degree of substitution, by varying ZSM-5 acidity could have significant benefits in terms creating a slate of upgraded biomass pyrolysis products to meet specific target market demands.« less

Highly sensitive analysis of polycyclic aromatic hydrocarbons in environmental water with porous cellulose/zeolitic imidazolate framework-8 composite microspheres as a novel adsorbent coupled with high-performance liquid chromatography.

PubMed

Liang, Xiaotong; Liu, Shengquan; Zhu, Rong; Xiao, Lixia; Yao, Shouzhuo

2016-07-01

In this work, novel cellulose/zeolitic imidazolate frameworks-8 composite microspheres have been successfully fabricated and utilized as sorbent for environmental polycyclic aromatic hydrocarbons efficient extraction and sensitive analysis. The composite microspheres were synthesized through the in situ hydrothermal growth of zeolitic imidazolate frameworks-8 on cellulose matrix, and exhibited favorable hierarchical structure with chemical composition as assumed through scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction patterns, and Brunauer-Emmett-Teller surface areas characterization. A robust and highly efficient method was then successfully developed with as-prepared composite microspheres as novel solid-phase extraction sorbent with optimum extraction conditions, such as sorbent amount, sample volume, extraction time, desorption conditions, volume of organic modifier, and ionic strength. The method exhibited high sensitivity with low limit of detection down to 0.1-1.0 ng/L and satisfactory linearity with correlation coefficients ranging from 0.9988 to 0.9999, as well as good recoveries of 66.7-121.2% with relative standard deviations less than 10% for environmental polycyclic aromatic hydrocarbons analysis. Thus, our method was convenient and efficient for polycyclic aromatic hydrocarbons extraction and detection, potential for future environmental water samples analysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydroxypropyl cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimers as effective carbohydrate-solubilizers for polycyclic aromatic hydrocarbons.

PubMed

Choi, Jae Min; Jeong, Daham; Piao, Jinglan; Kim, Kyoungtea; Nguyen, Andrew Bao Loc; Kwon, Nak-Jung; Lee, Mi-Kyung; Lee, Im Soon; Yu, Jae-Hyuk; Jung, Seunho

2015-01-12

The removal of polycyclic aromatic hydrocarbons by soil washing using water is extremely difficult due to their intrinsic hydrophobic nature. In this study, the effective aqueous solubility enhancements of seven polycyclic aromatic hydrocarbons by chemically modified hydroxypropyl rhizobial cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimer have been investigated for the first time. In the presence of hydroxypropyl cyclic β-(1 → 2)-D-glucans, the solubility of benzo[a]pyrene is increased up to 38 fold of its native solubility. The solubility of pyrene and phenanthrene dramatically increased up to 160 and 359. Coronene, chrysene, perylene, and fluoranthene also show an increase of 11, 23, 23, and 97 fold, respectively, of enhanced solubility by complexation with synthetic epichlorohydrin β-cyclodextrin dimer. The physicochemical properties of the complex are characterized by Fourier-transform infrared spectra and differential scanning calorimetry. Utilizing a scanning electron microscopy, the morphological structures of native benzo[a]pyrene, pyrene, phenanthrene, coronene, chrysene, perylene, fluoranthene and their complex with novel carbohydrate-solubilizers are studied. These results elucidate that polycyclic aromatic hydrocarbons are able to form an efficient complex with hydroxypropyl cyclic β-(1 → 2)-D-glucans and β-cyclodextrin dimer, suggesting the potential usage of chemically modified novel carbohydrate-solubilizers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessment of the bioavailability and phytotoxicity of sediment spiked with polycyclic aromatic hydrocarbons.

PubMed

Rončević, Srđan; Spasojević, Jelena; Maletić, Snežana; Jazić, Jelena Molnar; Isakovski, Marijana Kragulj; Agbaba, Jasmina; Grgić, Marko; Dalmacija, Božo

2016-02-01

Large amounts of sediment are dredged globally every year. This sediment is often contaminated with low concentrations of metals, polycyclic aromatic hydrocarbons, pesticides and other organic pollutants. Some of this sediment is disposed of on land, creating a need for risk assessment of the sediment disposal method, to minimize the degradation of environmental quality and prevent risks to human health. Evaluating the available fractions of certain polycyclic aromatic hydrocarbons is very important, as in the presence of various organisms, they are believed to be easily subject to the processes of bioaccumulation, biosorption and transformation. In order to determine the applicability of applying these methods for the evaluation of pollutant bioavailability in sediments, the desorption kinetics from the sediment of various polycyclic aromatic hydrocarbons in the presence of Tenax and XAD4 were examined over the course of 216 h. Changes in the PAH concentrations in dredged sediments using five different seed plants during a short time of period (10 days) were also followed. Using chemical extraction techniques with Tenax and XAD4, a time of around 24 h is enough to achieve equilibrium for all four PAHs. Results showed good agreement between the seed accumulation and PAH extraction methods with both agents. If we compare the two extraction techniques, XAD4 gave better results for phenanthrene, pyrene and benzo(a)pyrene, and Tenax gave better results for chrysene.

Emission characteristics of polycyclic aromatic hydrocarbons and nitro-polycyclic aromatic hydrocarbons from diesel trucks based on on-road measurements

NASA Astrophysics Data System (ADS)

Cao, Xinyue; Hao, Xuewei; Shen, Xianbao; Jiang, Xi; Wu, Bobo; Yao, Zhiliang

2017-01-01

Polycyclic aromatic hydrocarbon (PAH) and nitro-polycyclic aromatic hydrocarbon (NPAH) emissions from 18 diesel trucks of different sizes and with different emission standards were tested in Beijing using a portable emission measurement system (PEMS). Both the gaseous- and particulate-phase PAHs and NPAHs were quantified by high-performance liquid chromatography (HPLC) in the laboratory. The emission factors (EFs) of the total PAHs from light-duty diesel trucks (LDDTs), medium-duty diesel trucks (MDDTs) and heavy-duty diesel trucks (HDDTs) were 82229.11 ± 41906.06, 52867.43 ± 18946.47 and 93837.35 ± 32193.14 μg/km, respectively, much higher than the respective values of total NPAHs from their counterpart vehicles. The gaseous phase had an important contribution to the total PAHs and NPAHs, with a share rate of approximately 69% and 97% on average, respectively. The driving cycle had important impacts on the emissions of PAHs and NPAHs, especially for LDDTs and HDDTs. Higher emissions of PAHs and NPAHs were detected on non-highway roads compared to that on highways for these two types of vehicles. Compared to the results of different studies, the difference in the EFs of PAHs and NPAHs can reach several orders of magnitudes, which would introduce errors in the development of an emission inventory of PAHs and NPAHs.

Comparison of the solid-phase extraction efficiency of a bounded and an included cyclodextrin-silica microporous composite for polycyclic aromatic hydrocarbons determination in water samples.

PubMed

Mauri-Aucejo, Adela; Amorós, Pedro; Moragues, Alaina; Guillem, Carmen; Belenguer-Sapiña, Carolina

2016-08-15

Solid-phase extraction is one of the most important techniques for sample purification and concentration. A wide variety of solid phases have been used for sample preparation over time. In this work, the efficiency of a new kind of solid-phase extraction adsorbent, which is a microporous material made from modified cyclodextrin bounded to a silica network, is evaluated through an analytical method which combines solid-phase extraction with high-performance liquid chromatography to determine polycyclic aromatic hydrocarbons in water samples. Several parameters that affected the analytes recovery, such as the amount of solid phase, the nature and volume of the eluent or the sample volume and concentration influence have been evaluated. The experimental results indicate that the material possesses adsorption ability to the tested polycyclic aromatic hydrocarbons. Under the optimum conditions, the quantification limits of the method were in the range of 0.09-2.4μgL(-1) and fine linear correlations between peak height and concentration were found around 1.3-70μgL(-1). The method has good repeatability and reproducibility, with coefficients of variation under 8%. Due to the concentration results, this material may represent an alternative for trace analysis of polycyclic aromatic hydrocarbons in water trough solid-phase extraction. Copyright © 2016 Elsevier B.V. All rights reserved.

Enhanced bioavailability of polyaromatic hydrocarbons in the form of mucin complexes.

PubMed

Drug, Eyal; Landesman-Milo, Dalit; Belgorodsky, Bogdan; Ermakov, Natalia; Frenkel-Pinter, Moran; Fadeev, Ludmila; Peer, Dan; Gozin, Michael

2011-03-21

Increasing exposure of biological systems to large amounts of polycyclic aromatic hydrocarbons is of great public concern. Organisms have an array of biological defense mechanisms, and it is believed that mucosal gel (which covers the respiratory system, the gastrointestinal tract, etc.) provides an effective chemical shield against a range of toxic materials. However, in this work, we demonstrate, for the first time, that, upon complexation of polyaromatic hydrocarbons with mucins, enhanced bioavailability and, therefore, toxicity are obtained. This work was aimed to demonstrate how complexation of various highly hydrophobic polycyclic aromatic hydrocarbons with representative mucin glycoprotein could lead to the formation of previously undescribed materials, which exhibit increased toxicity versus pristine polycyclic aromatic hydrocarbons. In the present work, we show that a representative mucin glycoprotein, bovine submaxillary mucin, has impressive and unprecedented capabilities of binding and solubilizing water-insoluble materials in physiological solution. The complexes formed between the mucin and a series of polycyclic aromatic hydrocarbons were comprehensively characterized, and their toxicity was evaluated by both in vivo and in vitro assays. In addition, the bioavailability and membrane-penetration capabilities were tested using an internalization assay. Our results provide, for the first time, evidence of an unknown route by which hydrophobic materials may achieve higher bioavailability, penetrating some of the biological defense systems, in the form of water-soluble complexes with mucosal proteins.

Identification and quantification of seven fused aromatic rings C26H14 peri-condensed benzenoid polycyclic aromatic hydrocarbons in a complex mixture of polycyclic aromatic hydrocarbons from coal tar.

PubMed

Oña-Ruales, Jorge O; Ruiz-Morales, Yosadara; Wise, Stephen A

2016-04-15

A methodology for the characterization of groups of polycyclic aromatic hydrocarbons (PAHs) using a combination of normal phase liquid chromatography with ultraviolet-visible spectroscopy (NPLC/UV-vis) and gas chromatography with mass spectrometry (GC/MS) was used for the identification and quantification of seven fused aromatic rings C26H14 peri-condensed benzenoid polycyclic aromatic hydrocarbons, PAHs, in standard reference material (SRM) 1597a, complex mixture of PAHs from coal tar. The NPLC/UV-vis isolated the fractions based on the number of aromatic carbons and the GC/MS allowed the identification and quantification of five of the nine C26H14 PAH isomers; naphtho[1,2,3,4-ghi]perylene, dibenzo[b,ghi]perylene, dibenzo[b,pqr]perylene, naphtho[8,1,2-bcd]perylene, and dibenzo[cd,lm]perylene using a retention time comparison with authentic reference standards. For the other four benzenoid isomers with no available reference standards the following two approaches were used. First, the annellation theory was used to achieve the potential identification of benzo[qr]naphtho[3,2,1,8-defg]chrysene, and second, the elution distribution in the GC fractions was used to support the potential identification of benzo[qr]naphtho[3,2,1,8-defg]chrysene and to reach the tentative identifications of dibenzo[a,ghi]perylene, naphtho[7,8,1,2,3-pqrst]pentaphene, and anthra[2,1,9,8-opqra]naphthacene. It is the first time that naphtho[1,2,3,4-ghi]perylene, dibenzo[b,ghi]perylene, dibenzo[b,pqr]perylene, naphtho[8,1,2-bcd]perylene, and dibenzo[cd,lm]perylene are quantified, and the first time that benzo[qr]naphtho[3,2,1,8-defg]chrysene is potentially identified, in any sample, in any context. Copyright © 2016 Elsevier B.V. All rights reserved.

High-Resolution IR Absorption Spectroscopy of Polycyclic Aromatic Hydrocarbons: The Realm of Anharmonicity

NASA Technical Reports Server (NTRS)

Maltseva, Elena; Petrignani, Annemieke; Candian, Alessandra; Mackie, Cameron J.; Huang, Xinchuan; Lee, Timothy J.; Tielens, Alexander G. G. M.; Oomens, Jos; Buma, Wybren Jan

2016-01-01

We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3 micrometers CH stretching region of Polycyclic Aromatic Hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold ((is) approximately 4K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions enhanced with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main modes that fall within 0.5% of the experimental frequencies. The implications for the Aromatic Infrared Bands, specifically the 3-m band are discussed.

Analysis of polycyclic aromatic hydrocarbons extracted from air particulate matter using a temperature programmable injector coupled to GC-C-IRMS.

PubMed

Mikolajczuk, Agnieszka; Przyk, Elzbieta Perez; Geypens, Benny; Berglund, Michael; Taylor, Philip

2010-03-01

Compound specific isotopic analysis (CSIA) can provide information about the origin of analysed compounds - in this case, polycyclic aromatic hydrocarbons (PAHs). In the study, PAHs were extracted from three dust samples: winter and summer filter dust and tunnel dust. The measurement was performed using the method validated in our laboratory using pure, solid compounds and EPA 610 reference assortment. CSIA required an appropriate clean-up method to avoid an unresolved complex in the gas chromatographic analysis usually found in the chromatography of PAHs. Extensive sample clean-up for this particular matrix was found to be necessary to obtain good gas chromatography-combustion-isotope ratio mass spectrometry analysis results. The sample purification method included two steps in which the sample is cleaned up and the aliphatic and aromatic hydrocarbons are separated. The concentration of PAHs in the measured samples was low; so a large volume injection technique (100 microl) was applied. The delta(VPDB)(13)C was measured with a final uncertainty smaller than 1 per thousand. Comparison of the delta(VPDB)(13)C signatures of PAHs extracted from different dust samples was feasible with this method and, doing so, significant differences were observed.

Anaerobic Degradation of Benzene and Polycyclic Aromatic Hydrocarbons.

PubMed

Meckenstock, Rainer U; Boll, Matthias; Mouttaki, Housna; Koelschbach, Janina S; Cunha Tarouco, Paola; Weyrauch, Philip; Dong, Xiyang; Himmelberg, Anne M

2016-01-01

Aromatic hydrocarbons such as benzene and polycyclic aromatic hydrocarbons (PAHs) are very slowly degraded without molecular oxygen. Here, we review the recent advances in the elucidation of the first known degradation pathways of these environmental hazards. Anaerobic degradation of benzene and PAHs has been successfully documented in the environment by metabolite analysis, compound-specific isotope analysis and microcosm studies. Subsequently, also enrichments and pure cultures were obtained that anaerobically degrade benzene, naphthalene or methylnaphthalene, and even phenanthrene, the largest PAH currently known to be degradable under anoxic conditions. Although such cultures grow very slowly, with doubling times of around 2 weeks, and produce only very little biomass in batch cultures, successful proteogenomic, transcriptomic and biochemical studies revealed novel degradation pathways with exciting biochemical reactions such as for example the carboxylation of naphthalene or the ATP-independent reduction of naphthoyl-coenzyme A. The elucidation of the first anaerobic degradation pathways of naphthalene and methylnaphthalene at the genetic and biochemical level now opens the door to studying the anaerobic metabolism and ecology of anaerobic PAH degraders. This will contribute to assessing the fate of one of the most important contaminant classes in anoxic sediments and aquifers. © 2016 S. Karger AG, Basel.

HIGH-RESOLUTION IR ABSORPTION SPECTROSCOPY OF POLYCYCLIC AROMATIC HYDROCARBONS: THE REALM OF ANHARMONICITY

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

Maltseva, Elena; Buma, Wybren Jan; Petrignani, Annemieke

2015-11-20

We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3-μm CH stretching region of polycyclic aromatic hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold (∼4 K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computationalmore » program SPECTRO, providing anharmonic predictions with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main bands that fall within 0.5% of the experimental frequencies. The implications for the aromatic infrared bands, specifically the 3-μm band, are discussed.« less

INTERACTION ANALYSES OF BINARY MIXTURES OF CARCINOGENIC PAHS USING MORPHOLOGICAL CELL TRANSFORMATION OF C3H1OT1/2CL8 MOUSE EMBRYO FIBROBLASTS IN CULTURE.

EPA Science Inventory

Studies of defined mixtures of carcinogenic polycyclic aromatic hydrocarbons (PAH) have shown three major categories of interactions: antagonism, synergism, and additivity depending on the biological model, tissue, route of exposure, and specific PAH. To understand the bases of t...

Emission factors of particulate matter, polycyclic aromatic hydrocarbons, and levoglucosan from wood combustion in south-central Chile.

PubMed

Jimenez, Jorge; Farias, Oscar; Quiroz, Roberto; Yañez, Jorge

2017-07-01

In south-central Chile, wood stoves have been identified as an important source of air pollution in populated areas. Eucalyptus (Eucalyptus globulus), Chilean oak (Nothofagus oblique), and mimosa (Acacia dealbata) were burned in a single-chamber slow-combustion wood stove at a controlled testing facility located at the University of Concepción, Chile. In each experiment, 2.7-3.1 kg of firewood were combusted while continuously monitoring temperature, exhaust gases, burn rate, and collecting particulate matter samples in Teflon filters under isokinetic conditions for polycyclic aromatic hydrocarbon and levoglucosan analyses. Mean particulate matter emission factors were 2.03, 4.06, and 3.84 g/kg dry wood for eucalyptus, oak, and mimosa, respectively. The emission factors were inversely correlated with combustion efficiency. The mean emission factors of the sums of 12 polycyclic aromatic hydrocarbons in particle phases were 1472.5, 2134.0, and 747.5 μg/kg for eucalyptus, oak, and mimosa, respectively. Fluoranthene, pyrene, benzo[a]anthracene, and chrysene were present in the particle phase in higher proportions compared with other polycyclic aromatic hydrocarbons that were analyzed. Mean levoglucosan emission factors were 854.9, 202.3, and 328.0 mg/kg for eucalyptus, oak, and mimosa, respectively. Since the emissions of particulate matter and other pollutants were inversely correlated with combustion efficiency, implementing more efficient technologies would help to reduce air pollutant emissions from wood combustion. Residential wood burning has been identified as a significant source of air pollution in populated areas. Local wood species are combusted for home cooking and heating, which releases several toxic air pollutants, including particulate matter, carbon monoxide, and polycyclic aromatic hydrocarbons. Air pollutant emissions depend on the type of wood and the technology and operational conditions of the wood stove. A better understanding of emissions from local wood species and wood stove performance would help to identify better biomass fuels and wood stove technologies in order to reduce air pollution from residential wood burning.

Time-resolved analysis of particle emissions from residential biomass combustion - Emissions of refractory black carbon, PAHs and organic tracers

NASA Astrophysics Data System (ADS)

Nielsen, Ingeborg E.; Eriksson, Axel C.; Lindgren, Robert; Martinsson, Johan; Nyström, Robin; Nordin, Erik Z.; Sadiktsis, Ioannis; Boman, Christoffer; Nøjgaard, Jacob K.; Pagels, Joakim

2017-09-01

Time-resolved particle emissions from a conventional wood stove were investigated with aerosol mass spectrometry to provide links between combustion conditions, emission factors, mixing state of refractory black carbon and implications for organic tracer methods. The addition of a new batch of fuel results in low temperature pyrolysis as the fuel heats up, resulting in strong, short-lived, variable emission peaks of organic aerosol-containing markers of anhydrous sugars, such as levoglucosan (fragment at m/z 60). Flaming combustion results in emissions dominated by refractory black carbon co-emitted with minor fractions of organic aerosol and markers of anhydrous sugars. Full cycle emissions are an external mixture of larger organic aerosol-dominated and smaller thinly coated refractory black carbon particles. A very high burn rate results in increased full cycle mass emission factors of 66, 2.7, 2.8 and 1.3 for particulate polycyclic aromatic hydrocarbons, refractory black carbon, total organic aerosol and m/z 60, respectively, compared to nominal burn rate. Polycyclic aromatic hydrocarbons are primarily associated with refractory black carbon-containing particles. We hypothesize that at very high burn rates, the central parts of the combustion zone become air starved, leading to a locally reduced combustion temperature that reduces the conversion rates from polycyclic aromatic hydrocarbons to refractory black carbon. This facilitates a strong increase of polycyclic aromatic hydrocarbons emissions. At nominal burn rates, full cycle emissions based on m/z 60 correlate well with organic aerosol, refractory black carbon and particulate matter. However, at higher burn rates, m/z 60 does not correlate with increased emissions of polycyclic aromatic hydrocarbons, refractory black carbon and organic aerosol in the flaming phase. The new knowledge can be used to advance source apportionment studies, reduce emissions of genotoxic compounds and model the climate impacts of refractory black carbon, such as absorption enhancement by lensing.

Complete genome of Martelella sp. AD-3, a moderately halophilic polycyclic aromatic hydrocarbons-degrading bacterium.

PubMed

Cui, Changzheng; Li, Zhijie; Qian, Jiangchao; Shi, Jie; Huang, Ling; Tang, Hongzhi; Chen, Xin; Lin, Kuangfei; Xu, Ping; Liu, Yongdi

2016-05-10

Martelella sp. strain AD-3, a moderate halophilic bacterium, was isolated from a petroleum-contaminated soil with high salinity in China. Here, we report the complete genome of strain AD-3, which contains one circular chromosome and two circular plasmids. An array of genes related to metabolism of polycyclic aromatic hydrocarbons and halophilic mechanism in this bacterium was identified by the whole genome analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Tunable molecular plasmons in polycyclic aromatic hydrocarbons.

PubMed

Manjavacas, Alejandro; Marchesin, Federico; Thongrattanasiri, Sukosin; Koval, Peter; Nordlander, Peter; Sánchez-Portal, Daniel; García de Abajo, F Javier

2013-04-23

We show that chemically synthesized polycyclic aromatic hydrocarbons (PAHs) exhibit molecular plasmon resonances that are remarkably sensitive to the net charge state of the molecule and the atomic structure of the edges. These molecules can be regarded as nanometer-sized forms of graphene, from which they inherit their high electrical tunability. Specifically, the addition or removal of a single electron switches on/off these molecular plasmons. Our first-principles time-dependent density-functional theory (TDDFT) calculations are in good agreement with a simpler tight-binding approach that can be easily extended to much larger systems. These fundamental insights enable the development of novel plasmonic devices based upon chemically available molecules, which, unlike colloidal or lithographic nanostructures, are free from structural imperfections. We further show a strong interaction between plasmons in neighboring molecules, quantified in significant energy shifts and field enhancement, and enabling molecular-based plasmonic designs. Our findings suggest new paradigms for electro-optical modulation and switching, single-electron detection, and sensing using individual molecules.

ATR-FTIR spectroscopy reveals polycyclic aromatic hydrocarbon contamination despite relatively pristine site characteristics: Results of a field study in the Niger Delta.

PubMed

Obinaju, Blessing E; Martin, Francis L

2016-01-01

Fourier-transform infrared (FTIR) spectroscopy is an emerging technique to detect biochemical alterations in biological tissues, particularly changes due to sub-lethal exposures to environmental contaminants. We have previously shown the potential of attenuated total reflection FTIR (ATR-FTIR) spectroscopy to detect real-time exposure to contaminants in sentinel organisms as well as the potential to relate spectral alterations to the presence of specific environmental agents. In this study based in the Niger Delta (Nigeria), changes occurring in fish tissues as a result of polycyclic aromatic hydrocarbon (PAH) exposure at contaminated sites are compared to the infrared (IR) spectra of the tissues obtained from a relatively pristine site. Multivariate analysis revealed that PAH contamination could be occurring at the pristine site, based on the IR spectra and significant (P<0.0001) differences between sites. The study provides evidence of the IR spectroscopy techniques' sensitivity and supports their potential application in environmental biomonitoring. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of heavy metals and polycyclic aromatic hydrocarbons in honeys from different origins.

PubMed

Corredera, Lourdes; Bayarri, Susana; Pérez-Arquillué, Consuelo; Lázaro, Regina; Molino, Francisco; Herrera, Antonio

2014-03-01

A survey of honey samples from different geographical and botanical origins, including some samples collected from a fire-affected area in Spain, was conducted to assess their content of heavy metals and polycyclic aromatic hydrocarbons (PAHs). The levels of the determined toxic elements (Pb, Cd, As, and Sn) were low and were in the range of those reported by other studies. In our work the total amount of heavy metals and Pb was higher in dark honeys than in pale honeys. In the collected samples, no detectable levels of the 15 PAHs studied were found. The obtained data served to assess the levels of heavy metals and PAHs in honey samples from different geographical and environmental origins and to contribute to the scarce data about pollutant content of this matrix. In light of these results, the analyzed samples do not pose any serious concern to human health, and the data obtained in this study could serve to contribute to the establishment of specific maximum limits for honey.

Application of binary diagnostic ratios of polycyclic aromatic hydrocarbons for identification of Tsunami 2004 backwash sediments in Khao Lak, Thailand.

PubMed

Pongpiachan, Siwatt

2014-01-01

Identification of Tsunami deposits has long been a controversial issue among geologists. Although there are many identification criteria based on the sedimentary characteristics of unequivocal Tsunami deposits, the concept still remains ambiguous. Apart from relying on some conventional geological, sedimentological, and geoscientific records, geologists need some alternative "proxies" to identify the existence of Tsunami backwash in core sediments. Polycyclic aromatic hydrocarbons (PAHs) are a class of very stable organic molecules, which can usually be presented as complex mixtures of several hundred congeners; one can assume that the "Tsunami backwash deposits" possess different fingerprints of PAHs apart from those of "typical marine sediments." In this study, three-dimensional plots of PAH binary ratios successfully identify the Tsunami backwash deposits in comparison with those of global marine sediments. The applications of binary ratios of PAHs coupled with HCA are the basis for developing site-specific Tsunami deposit identification criteria that can be applied in paleotsunami deposits investigations.

Polycyclic aromatic hydrocarbons in ambient air, surface soil and wheat grain near a large steel-smelting manufacturer in northern China.

PubMed

Liu, Weijian; Wang, Yilong; Chen, Yuanchen; Tao, Shu; Liu, Wenxin

2017-07-01

The total concentrations and component profiles of polycyclic aromatic hydrocarbons (PAHs) in ambient air, surface soil and wheat grain collected from wheat fields near a large steel-smelting manufacturer in Northern China were determined. Based on the specific isomeric ratios of paired species in ambient air, principle component analysis and multivariate linear regression, the main emission source of local PAHs was identified as a mixture of industrial and domestic coal combustion, biomass burning and traffic exhaust. The total organic carbon (TOC) fraction was considerably correlated with the total and individual PAH concentrations in surface soil. The total concentrations of PAHs in wheat grain were relatively low, with dominant low molecular weight constituents, and the compositional profile was more similar to that in ambient air than in topsoil. Combined with more significant results from partial correlation and linear regression models, the contribution from air PAHs to grain PAHs may be greater than that from soil PAHs. Copyright © 2016. Published by Elsevier B.V.

Influence of rice straw burning on the levels of polycyclic aromatic hydrocarbons in agricultural county of Taiwan.

PubMed

Lai, Chia-Hsiang; Chen, Kang-Shin; Wang, Hsin-Kai

2009-01-01

Atmospheric particulate and polycyclic aromatic hydrocarbons (PAHs) size distribution were measured at Jhu-Shan (a rural site) and Sin-Gang (a town site) in central Taiwan during the rice straw burning and non-burning periods. The concentrations of total PAHs accounting for a roughly 58% (34%) increment in the concentrations of total PAHs due to rice-straw burning. Combustion-related PAHs during burning periods were 1.54-2.57 times higher than those during non-burning periods. The mass median diameter (MMD) of 0.88-1.21 microm in the particulate phase suggested that rice-straw burning generated the increase in coarse particle number. Chemical mass balance (CMB) receptor model analyses showed that the primary pollution sources at the two sites were similar. However, rice-straw burning emission was specifically identified as a significant source of PAH during burning periods at the two sites. Open burning of rice straws was estimated to contribute approximately 6.3%-24.6% to total atmospheric PAHs at the two sites.

Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment.

PubMed

Mishra, Nitika; Ayoko, Godwin A; Morawska, Lidia

2016-01-01

Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis - Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Selective treatment to reduce contamination of propolis by polycyclic aromatic hydrocarbons (PAHs) still preserving its active polyphenol component and antioxidant activity.

PubMed

Galeotti, Fabio; Crimaldi, Laura; Maccari, Francesca; Zaccaria, Vincenzo; Fachini, Alfredo; Volpi, Nicola

2017-09-01

The adverse effects on health and environment caused by polycyclic aromatic hydrocarbons (PAHs) are critical problems. EFSA has defined 16 priority PAHs that are both genotoxic and carcinogenic, and identified eight (PAH8) priority PAHs as good indicators of the toxicity and occurrence in food. Food supplements containing propolis were also found to contain relatively high quantities of PAHs. We report about an extractive procedure which is able to purify propolis from a high content of PAHs using a balanced mixture of ethanol and water solvents. Extracts were characterised for total content of polyphenols, for in vitro antioxidant activity, and single classes of polyphenols evaluated by HPLC-ESI-MS. Obtained propolis extracts were found to have PAH8 and specific benzo[a]pyrene content below limits recommended by EFSA. The reported extractive procedure is easily applicable for possible industrial productions and may also be adopted to the purification of polyphenols from other plant extracts and natural sources.

Graphene-based solid-phase extraction disk for fast separation and preconcentration of trace polycyclic aromatic hydrocarbons from environmental water samples.

PubMed

Wang, Zonghua; Han, Qiang; Xia, Jianfei; Xia, Linhua; Ding, Mingyu; Tang, Jie

2013-06-01

Graphene has great potentials for the use in sample preparation due to its ultra high specific surface area, superior chemical stability, and excellent thermal stability. In our work, a novel graphene-based SPE disk was developed for separation and preconcentration of trace polycyclic aromatic hydrocarbons from environmental water samples. Based on the strong π-π stacking interaction between the analytes and graphene, the analytes extracted by graphene were eluted by cyclohexane and then determined by GC-MS. Under the optimized conditions, high flow rate (30 mL/min) and sensitivity (0.84-13 ng/L) were achieved. The proposed method was successfully applied to the analysis of real environmental water samples with recoveries ranging from 72.8 to 106.2%. Furthermore, the property of anticlogging and reusability was also improved. This work reveals great potentials of graphene-based SPE disk in environmental analytical. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Problems in the fingerprints based polycyclic aromatic hydrocarbons source apportionment analysis and a practical solution.

PubMed

Zou, Yonghong; Wang, Lixia; Christensen, Erik R

2015-10-01

This work intended to explain the challenges of the fingerprints based source apportionment method for polycyclic aromatic hydrocarbons (PAH) in the aquatic environment, and to illustrate a practical and robust solution. The PAH data detected in the sediment cores from the Illinois River provide the basis of this study. Principal component analysis (PCA) separates PAH compounds into two groups reflecting their possible airborne transport patterns; but it is not able to suggest specific sources. Not all positive matrix factorization (PMF) determined sources are distinguishable due to the variability of source fingerprints. However, they constitute useful suggestions for inputs for a Bayesian chemical mass balance (CMB) analysis. The Bayesian CMB analysis takes into account the measurement errors as well as the variations of source fingerprints, and provides a credible source apportionment. Major PAH sources for Illinois River sediments are traffic (35%), coke oven (24%), coal combustion (18%), and wood combustion (14%). Copyright © 2015. Published by Elsevier Ltd.

Investigation of the Reactions and Distribution of Polycyclic Aromatic Hydrocarbons and Fullerenes in Extraterrestrial Material

NASA Technical Reports Server (NTRS)

Zare, Richard N.

2005-01-01

The work funded by this research grant includes four specific projects: (1) Mapping the spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in a variety of meteoritic samples and comparing this distribution with mineralogical features of the meteorite to determine whether a correlation exists between the two. (2) Developing a method for detection of fullerenes in extraterrestrial samples using microprobe laser-desorption laser-ionization mass spectrometry ( pL2MS) and utilizing this technique to investigate fullerene presence, while exploring the possibility of spatially mapping the fullerene distribution in these samples through in situ detection. (3) Investigating a possible formation pathway for meteoritic and ancient terrestrial kerogen involving the photochemical reactions of PAHs with alkanes under prebiotic and astrophysically relevant conditions. (4) Studying reaction pathways and identifying the photoproducts generated during the photochemical evolution of PAH-containing interstellar ice analogs as part of an ongoing collaboration with researchers at the Astrochemistry Lab at NASA Ames.

Tetrachlorinated Polycyclic Aromatic Dicarboximides: New Electron-Poor Π-Scaffolds and NIR Emitters by Palladium-Catalyzed Annulation Reaction.

PubMed

Mahl, Magnus; Shoyama, Kazutaka; Rühe, Jessica; Grande, Vincenzo; Würthner, Frank

2018-04-24

Herein we report a palladium-catalyzed annulation reaction consisting of a Suzuki-Miyaura cross-coupling and a C-H arylation cascade for the synthesis of tetrachlorinated polycyclic aromatic dicarboximides (PADIs). This convergent synthetic route afforded a broad series of hitherto unknown electron-deficient PADIs under optimized reaction conditions by coupling of a dibromo-tetrachloro-perylene dicarboximide with different polycyclic aromatic hydrocarbon (PAH) boronic acid pinacol esters in up to 89% yields. The new PADI compounds show broad absorption in the visible range and some of them emit in the near-infrared (NIR) region. Cyclic and square wave voltammetric studies revealed that these tetrachlorinated PADIs are more electron-deficient than a non-chlorinated reference compound and they possess lower lying frontier orbitals. Thus, the newly synthesized electron-poor PADIs are potential n-type semiconductors. Moreover, these chlorinated PADIs are interesting building blocks for the construction of large π-extended arrays by metal-mediated coupling reactions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Distributions of polycyclic aromatic hydrocarbons and alkylated polycyclic aromatic hydrocarbons in Osaka Bay, Japan.

PubMed

Miki, Shizuho; Uno, Seiichi; Ito, Kazuki; Koyama, Jiro; Tanaka, Hiroyuki

2014-08-30

Contaminations in sediments by polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs were investigated at 44 sites in Osaka Bay, Japan. Concentrations of total PAHs and alkylated PAHs were in the range 6.40-7800 ng/g dry weights and 13.7-1700 ng/g dry weights, respectively. The PAH concentrations tended to be higher along the shoreline in the vicinities of big ports, industrialized areas, and densely populated regions such as the cities of Osaka and Kobe. The major sources appeared to be pyrogenic or both pyrogenic and petrogenic at most of the sites. PAH concentrations were remarkably high at a site near Kobe, where the concentrations of dibenzo(a,h)anthracene and benzo(g,h,i)perylene exceeded the effects-range-medium concentration and eight PAHs were above the corresponding effects-range-low concentrations. Those PAHs may have been derived from the great fire associated with the large earthquake in 1995. Copyright © 2014 Elsevier Ltd. All rights reserved.

Petroleum hydrocarbons in the surface water of two estuaries in the Southeastern united states

NASA Astrophysics Data System (ADS)

Bidleman, T. F.; Castleberry, A. A.; Foreman, W. T.; Zaranski, M. T.; Wall, D. W.

1990-01-01

Surface water samples from Charleston Harbor, SC and Winyah Bay, SC were analysed for total hydrocarbons by gas chromatography (GC) and for petroleum residues (expressed as crude oil equivalents) by fluorescence spectrometry. Cleanup by column chromatography and saponification was necessary to reduce the background from extraneous fluorescing materials. Oil concentrations determined by FS ranged from 0·5-25 μg l -1 in Charleston Harbor and <0·23-9·6 μg l -1 in Winyah Bay. Hydrocarbons determined by GC were significantly correlated ( P < 0·01) with crude oil equivalents determined by FS, but the data showed considerable scatter as indicated by r2 = 0·45. Polycyclic aromatic hydrocarbons were determined by gas chromatography—mass spectrometry for one set of Winyah Bay samples. The sum of nonalkylated polycyclic aromatic hydrocarbons having ≥ 3 rings ranged from 7-64 ng l -1 at different stations. Perylene, possibly originating from sediment dredging, was one of the more abundant polycyclic aromatic hydrocarbons.

Concentration of polycyclic aromatic hydrocarbons in water samples from different stages of treatment

NASA Astrophysics Data System (ADS)

Pogorzelec, Marta; Piekarska, Katarzyna

2017-11-01

The aim of this study was to analyze the presence and concentration of selected polycyclic aromatic hydrocarbons in water samples from different stages of treatment and to verify the usefulness of semipermeable membrane devices for analysis of drinking water. For this purpose, study was conducted for a period of 5 months. Semipermeable membrane devices were deployed in a surface water treatment plant located in Lower Silesia (Poland). To determine the effect of water treatment on concentration of PAHs, three sampling places were chosen: raw water input, stream of water just before disinfection and treated water output. After each month of sampling SPMDs were changed for fresh ones and prepared for further analysis. Concentrations of fifteen polycyclic aromatic hydrocarbons were determined by high performance liquid chromatography (HPLC). Presented study indicates that the use of semipermeable membrane devices can be an effective tool for the analysis of aquatic environment, including monitoring of drinking water, where organic micropollutants are present at very low concentrations.

Biosurfactant produced by novel Pseudomonas sp. WJ6 with biodegradation of n-alkanes and polycyclic aromatic hydrocarbons.

PubMed

Xia, Wenjie; Du, Zhifeng; Cui, Qingfeng; Dong, Hao; Wang, Fuyi; He, Panqing; Tang, YongChun

2014-07-15

Alkanes and polycyclic aromatic hydrocarbons (PAHs) have threatened the environment due to toxicity and poor bioavailability. Interest in degradation of these hazardous materials by biosurfactant-producing bacteria has been steadily increasing in recent years. In this work, a novel biosurfactant-producing Pseudomonas sp. WJ6 was isolated to degrade a wide range of n-alkanes and polycyclic aromatic hydrocarbons. Production of lipopeptide biosurfactant was observed in all biodegradable studies. These lipopeptides were purified and identified by C18 RP-HPLC system and electrospray ionization-mass spectrometry. Results of structural analysis showed that these lipopeptides generated from different hydrocarbons were classified to be surfactin, fengycin and lichenysin. Heavy-oil sludge washing experiments demonstrated that lipopeptides produced by Pseudomonas sp. WJ6 have 92.46% of heavy-oil washing efficiency. The obtained results indicate that this novel bacterial strain and its lipopeptides have great potentials in the environmental remediation and petroleum recovery. Copyright © 2014 Elsevier B.V. All rights reserved.

Normal-phase liquid chromatography retention behavior of polycyclic aromatic sulfur heterocycles and alkyl-substituted polycyclic aromatic sulfur heterocycle isomers on an aminopropyl stationary phase.

PubMed

Wilson, Walter B; Hayes, Hugh V; Sander, Lane C; Campiglia, Andres D; Wise, Stephen A

2018-02-01

Retention indices for 67 polycyclic aromatic sulfur heterocycles (PASHs) and 80 alkyl-substituted PASHs were determined using normal-phase liquid chromatography (NPLC) on an aminopropyl (NH 2 ) stationary phase. The retention behavior of PASH on the NH 2 phase is correlated with the number of aromatic carbon atoms and two structural characteristics have a significant influence on their retention: non-planarity (thickness, T) and the position of the sulfur atom in the bay-region of the structure. Correlations between solute retention on the NH 2 phase and T of PASHs were investigated for three cata-condensed (cata-) PASH isomer groups: (a) 13 four-ring molecular mass (MM) 234 Da cata-PASHs, (b) 20 five-ring MM 284 Da cata-PASHs, and (c) 12 six-ring MM 334 Da cata-PASHs. Correlation coefficients ranged from r = -0.49 (MM 234 Da) to r = -0.65 (MM 334 Da), which were significantly lower than structurally similar PAH isomer groups (r = -0.70 to r = -0.99). The NPLC retention behavior of the PASHs are compared to similar results for PAHs.

Determination of polycyclic aromatic hydrocarbons in fractions in asphalt mixtures using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization.

PubMed

Nascimento, Paulo Cicero; Gobo, Luciana Assis; Bohrer, Denise; Carvalho, Leandro Machado; Cravo, Margareth Coutinho; Leite, Leni Figueiredo Mathias

2015-07-01

An analytical method using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization for the determination of polycyclic aromatic hydrocarbons in asphalt fractions has been developed. The 14 compounds determined, characterized by having two or more condensed aromatic rings, are expected to be present in asphalt and are considered carcinogenic and mutagenic. The parameters of the atmospheric pressure chemical ionization interface were optimized to obtain the highest possible sensitivity for all of the compounds. The limits of detection ranged from 0.5 to 346.5 μg/L and the limits of quantification ranged from 1.7 to 1550 μg/L. The method was validated against a diesel particulate extract standard reference material (NIST SRM 1975), and the obtained concentrations agreed with the certified values. The method was applied to asphalt samples after its fractionation according to ASTM D4124 and the method of Green. The concentrations of the seven polycyclic aromatic hydrocarbons quantified in the sample ranged from 0.86 mg/kg for benzo[ghi]perylene to 98.32 mg/kg for fluorene. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photooxidation products of polycyclic aromatic compounds containing sulfur.

PubMed

Bobinger, Stefan; Andersson, Jan T

2009-11-01

Photooxidation of crude oil components is an important process that removes pollutants from the environment. Polycyclic aromatic compounds (PACs) are known to be toxic to many life forms, but little is known about their photooxidation products in the aqueous phase. We here identify a large number of photoproducts from 11 benzothiophenes, a polycyclic aromatic sulfur heterocycle that is a major representative of PACs in crude oil. The investigated compounds contain two to four methyl groups and an ethyl or an n-octyl group. In water, the products arise through oxidation of alkyl side chains to aldehydes and carboxylic acids or through an opening in one of the aromatic rings. The product analysis was performed using gas chromatography with mass spectrometric or atomic emission detection. The main product is always a sulfobenzoic acid, which strongly lowers the pH of the solution. With long alkyl substituents, surfactants are formed, which may possess solubilizing properties in water. The larger the number of alkyl groups, the faster is the photooxidation. Several of the identified acidic compounds were also found when whole crude oil was photooxidized, showing that simulation with individual compounds reflects the situation in whole crude.

Variations in the 6.2 μm emission profile in starburst-dominated galaxies: a signature of polycyclic aromatic nitrogen heterocycles (PANHs)?

NASA Astrophysics Data System (ADS)

Canelo, Carla M.; Friaça, Amâncio C. S.; Sales, Dinalva A.; Pastoriza, Miriani G.; Ruschel-Dutra, Daniel

2018-04-01

Analyses of the polycyclic aromatic hydrocarbon (PAH) feature profiles, especially the 6.2 μm feature, could indicate the presence of nitrogen incorporated in their aromatic rings. In this work, 155 predominantly starburst-dominated galaxies (including H II regions and Seyferts, for example), extracted from the Spitzer/Infrared Spectrograph ATLAS project, have their 6.2 μm profiles fitted allowing their separation into the Peeters' A, B, and C classes. 67 per cent of these galaxies were classified as class A, 31 per cent were as class B, and 2 per cent as class C. Currently, class A sources, corresponding to a central wavelength near 6.22 μm, seem only to be explained by polycyclic aromatic nitrogen heterocycles (PANHs), whereas class B may represent a mix between PAHs and PANHs emissions or different PANH structures or ionization states. Therefore, these spectra suggest a significant presence of PANHs in the interstellar medium (ISM) of these galaxies that could be related to their starburst-dominated emission. These results also suggest that PANHs constitute another reservoir of nitrogen in the Universe, in addition to the nitrogen in the gas phase and ices of the ISM.

Method for the simultaneous determination of monoaromatic and polycyclic aromatic hydrocarbons in industrial effluents using dispersive liquid-liquid microextraction with gas chromatography-mass spectrometry.

PubMed

Makoś, Patrycja; Fernandes, André; Boczkaj, Grzegorz

2018-06-01

We present a new method for simultaneous determination of 22 monoaromatic and polycyclic aromatic hydrocarbons in postoxidative effluents from the production of petroleum bitumen using dispersive liquid-liquid microextraction coupled to gas chromatography and mass spectrometry. The eight extraction parameters including the type and volume of extraction and disperser solvent, pH, salting out effect, extraction, and centrifugation time were optimized. The low detection limit ranging from 0.36 to 28 μg/L, limit of quantitation (1.1-84 μg/L), good reproducibility, and wide linear ranges, as well as the recoveries ranging from 71.74 to 114.67% revealed that the new method allows the determination of aromatic hydrocarbons at low concentration levels in industrial effluents having a very complex composition. The developed method was applied to the determination of content of mono- and polycyclic aromatic hydrocarbons in samples of raw postoxidative effluents in which 15 compounds were identified at concentrations ranging from 1.21 to 1017.0 μg/L as well as in effluents after chemical treatment. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biodegradation of polycyclic 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. Analysis by capillary gas chromatography and high-performance li...

Role of Kekulé and Non-Kekulé Structures in the Radical Character of Alternant Polycyclic Aromatic Hydrocarbons: A TAO-DFT Study

PubMed Central

Yeh, Chia-Nan; Chai, Jeng-Da

2016-01-01

We investigate the role of Kekulé and non-Kekulé structures in the radical character of alternant polycyclic aromatic hydrocarbons (PAHs) using thermally-assisted-occupation density functional theory (TAO-DFT), an efficient electronic structure method for the study of large ground-state systems with strong static correlation effects. Our results reveal that the studies of Kekulé and non-Kekulé structures qualitatively describe the radical character of alternant PAHs, which could be useful when electronic structure calculations are infeasible due to the expensive computational cost. In addition, our results support previous findings on the increase in radical character with increasing system size. For alternant PAHs with the same number of aromatic rings, the geometrical arrangements of aromatic rings are responsible for their radical character. PMID:27457289

CYP63A2, a catalytically versatile fungal P450 monooxygenase capable of oxidizing higher-molecular-weight polycyclic aromatic hydrocarbons, alkylphenols, and alkanes

EPA Science Inventory

Cytochrome P450 monooxygenases (P450s) are known to oxidize hydrocarbons albeit with limited substrate specificity across classes of these compounds. Here we report a P450 monooxygenase (CYP63A2) from the model ligninolytic white rot fungus Phanerochaete chrysosporium that was fo...

PAH Emission in the Orion Bar

NASA Technical Reports Server (NTRS)

Bregman, Jesse; Sloan, G. C.

1996-01-01

The emission from polycyclic aromatic hydrocarbons (PAH's) in the Orion Bar region is investigated using a combination of narrow-band imaging and long-slit spectroscopy. The goal was to study how the strength of the PAH bands vary with spatial position in this edge-on photo-dissociation region. The specific focus here is how these variations constrain the carrier of the 3.4 micron band.

MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS

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

Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare

We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproducemore » the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 Multiplication-Sign 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.« less

Laboratory rotational spectroscopy of cyano substituted polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

McNaughton, Don; Jahn, Michaela K.; Travers, Michael J.; Wachsmuth, Dennis; Godfrey, Peter D.; Grabow, Jens-Uwe

2018-06-01

The rotational spectra of the four cyano substituted polycyclic aromatic hydrocarbon (PAH) molecules 1-cyanonaphthalene, 2-cyanonaphthalene, 9-cyanoanthracene, and 9-cyanophenanthrene have been recorded in molecular expansions using a Stark-modulated millimetre-wave spectrometer and a Fourier transform microwave spectrometer in the centimetre-wave region. The spectra have been assigned and fitted to provide molecular constants and quadrupole hyperfine constants of sufficient accuracy to enable complete hyperfine structure line predictions for interstellar searches. The data may provide a route into detection of small PAHs in the interstellar medium.

Microwave-assisted extraction of polycyclic aromatic compounds from coal.

PubMed

Kerst, M; Andersson, J T

2001-08-01

Microwave-assisted extraction (MAE) of polycyclic aromatic compounds (PACs) from coal is shown to give the same pattern of compounds as Soxhlet extraction. MAE requires only 10 mL solvent and 10 min extraction time whereas Soxhlet uses 200 mL and takes 24 h. Although the yields were lower, dichloromethane (DCM) was preferred to pyridine, N-methyl-2-pyrrolidone (NMP), and NMP with CS2 because the pattern of the PACs is shown to be independent of solvent and DCM is a much more convenient solvent to work with.

Petroleum and individual polycyclic aromatic hydrocarbons

USGS Publications Warehouse

Albers, Peter H.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

1995-01-01

Crude petroleum, refined-petroleum products, and individual polycyclic aromatic hydrocarbons (PAHs) contained within petroleum are found throughout the world. their presence has been detected in living and nonliving components of ecosystems. Petroleum can be an environmental hazard for wild animals and plants. Individual PAHs are also hazardous to wildlife, but they are most commonly associated with human illnesses. Because petroleum is a major environmental source of these PAHs, petroleum and PAHs are jointly presented in this chapter. Composition, sources, environmental fate, and toxic effects on all living components of aquatic and terrestrial environments are addessed.

New Molecular Detections in TMC-1 with the Green Bank Telescope: Carbon-Chain and Aromatic Molecules

NASA Astrophysics Data System (ADS)

Burkhardt, Andrew Michael

2018-01-01

Polycyclic aromatic hydrocarbons (PAHs) and polycyclic aromatic nitrogen heterocycles PA(N)Hs are believed to be widespread throughout the Universe, and are likely responsible for the unidentified infrared bands. However, the individual detection of aromatic molecules has been limited to a single weak absorption feature of an infrared bending mode of benzene (c-C6H6). The cold core TMC-1 has long been a source of new molecular detections, particularly for unsaturated carbon-rich molecules that are appealing potential precursors of PA(N)Hs. Through deep observations with the Green Bank Telescope of TMC-1, we report the first rotational detection of an aromatic molecule, benzonitrile (c-C6H5CN), along with 8 new isotopologues of HC5N and HC7N and an entirely new molecular family (HC5O, HC7O). These new detections provide crucial insights to the formation of PAHs and the underlying carbon-chain chemistry of dark clouds.

Determination of thiaarenes and polycyclic aromatic hydrocarbons in workplace air of an aluminum reduction plant

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

Becker, G.; Colmsjoe, A.; Oestman, C.

1999-05-01

Quantitation of a variety of tetra-, penta-, and hexacyclic aromatic sulfur heterocycles (thiaarenes) in workplace air of an aluminum reduction plant has been made by help of gas chromatography with atomic emission detection (GC-AED). Personal exposure to those thiaarenes and to polycyclic aromatic hydrocarbons depending on work categories has been evaluated. Summarized concentrations of the thiaarenes investigated have been found to be 0.4--19.0 {micro}g/m{sup 3}. When using sulfur selective AED, samples could be analyzed without a prior separation of the thiaarenes from the PAH. The present data indicate a contribution of thiaarenes to the overall toxicity of coal tar pitchmore » volatiles in this work environment.« less

Organic Molecules On the Surfaces of Iapetus and Phoebe

NASA Technical Reports Server (NTRS)

Pendleton, Yvonne J.; Dalle Ore, Cristina M.; Clark, Roger N.; Cruikshank, Dale P.

2017-01-01

Absorption bands of both aliphatic and aromatic organic molecules are found in the reflectance spectra of Saturn satellites Iapetus, Phoebe, and Hyperion obtained with the Cassini Visible-Infrared Mapping Spectrometer (VIMS). The VIMS data do not fully resolve the individual bands of C-H functional groups specific to particular molecules, but instead show absorption envelopes representing blended clusters of the bands of aromatic (approximately 3.28 microns) and aliphatic (approximately 3.4 microns) hydrocarbons known in spectra of interstellar dust. In Cruikshank et al. (2014), we matched components of the unresolved hydrocarbon band envelopes with clusters of bands of a range of functional groups in specific types of organic compounds (e.g., normal and N-substituted polycyclic aromatic hydrocarbons, olefins, cycloalkanes, and molecules with lone-pair interactions of N and O with CH3+). In the work reported here, we revisit the spectra of Iapetus and Phoebe using VIMS data processed with improved radiometric and wavelength calibration (denoted RC19). The band envelopes of both aromatic and aliphatic hydrocarbons are now more clearly defined, corroborating the provisional assignment of specific classes of molecules in Cruikshank et al. 2014, but permitting a more reliable quantitative assessment of the relative contributions of those classes, and a revision to the earlier estimate of the ratio of the abundances of aromatic to aliphatic molecules.

Polycyclic Aromatic Hydrocarbons Adsorption onto Graphene: A DFT and AIMD Study.

PubMed

Li, Bing; Ou, Pengfei; Wei, Yulan; Zhang, Xu; Song, Jun

2018-05-03

Density functional theory (DFT) calculations and ab-initio molecular dynamics (AIMD) simulations were performed to understand graphene and its interaction with polycyclic aromatic hydrocarbons (PAHs) molecules. The adsorption energy was predicted to increase with the number of aromatic rings in the adsorbates, and linearly correlate with the hydrophobicity of PAHs. Additionally, the analysis of the electronic properties showed that PAHs behave as mild n-dopants and introduce electrons into graphene; but do not remarkably modify the band gap of graphene, indicating that the interaction between PAHs and graphene is physisorption. We have also discovered highly sensitive strain dependence on the adsorption strength of PAHs onto graphene surface. The AIMD simulation indicated that a sensitive and fast adsorption process of PAHs can be achieved by choosing graphene as the adsorbent. These findings are anticipated to shed light on the future development of graphene-based materials with potential applications in the capture and removal of persistent aromatic pollutants.

Chemical quality of water, sediment, and fish in Mountain Creek Lake, Dallas, Texas, 1994-97

USGS Publications Warehouse

Van Metre, Peter C.; Jones, S.A.; Moring, J. Bruce; Mahler, B.J.; Wilson, Jennifer T.

2003-01-01

The occurrence, trends, and sources of numerous inorganic and organic contaminants were evaluated in Mountain Creek Lake, a reservoir in Dallas, Texas. The study, done in cooperation with the Southern Division Naval Facilities Engineering Command, was prompted by the Navy’s concern for potential off-site migration of contaminants from two facilities on the shore of Mountain Creek Lake, the Naval Air Station Dallas and the Naval Weapons Industrial Reserve Plant. Sampling of stormwater (including suspended sediment), lake water, bottom sediment (including streambed sediment), and fish was primarily in Mountain Creek Lake but also was in stormwater outfalls from the Navy facilities, nearby urban streams, and small streams draining the Air Station.Volatile organic compounds, predominantly solvents from the Reserve Plant and fuel-related compounds from the Air Station, were detected in stormwater from both Navy facilities. Fuel-related compounds also were detected in Mountain Creek Lake at two locations, one near the Air Station inlet where stormwater from a part of the Air Station enters the lake and one at the center of the lake. Concentrations of volatile organic compounds at the two lake sites were small, all less than 5 micrograms per liter.Elevated concentrations of cadmium, chromium, copper, lead, mercury, nickel, silver, and zinc, from 2 to 4 times concentrations at background sites and urban reference sites, were detected in surficial bottom sediments in Cottonwood Bay, near stormwater outfalls from the Reserve Plant. Elevated concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls, compared to background and urban reference sites, were detected in surficial sediments in Cottonwood Bay. Elevated concentrations of polycyclic aromatic hydrocarbons, indicative of urban sources, also were detected in Cottonwood Creek, which drains an urbanized area apart from the Navy facilities. Elevated concentrations of polychlorinated biphenyls were detected in two inlets near the Air Station shoreline. Polycyclic aromatic hydrocarbon and heavy metal concentrations near the Air Station shoreline were not elevated compared to urban reference sites.Much larger concentrations of selected heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls were detected in deeper, older sediments than in surficial sediments in Cottonwood Bay. The decreases in concentrations coincide with changes in wastewater discharge practices at the Reserve Plant. Elevated concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls also were detected in older sediments in the Air Station inlet.On the basis of dated sediment cores and contaminant discharge histories, contaminant accumulation rates in Cottonwood Bay were much greater historically than recently. Most heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls that accumulated in the central and eastern parts of Cottonwood Bay appear to have come from the west lagoon on the Reserve Plant. Treated sewage and industrial-process wastewater were discharged to the west lagoon from about 1941 to 1974. Estimated annual contaminant accumulation rates in Cottonwood Bay decreased by from 1 to 2 orders of magnitude after 1974, when most point-source discharges to the west lagoon ceased.Polychlorinated biphenyls were detected in 61 of 62 individual fish-tissue samples. The largest average concentrations were in eviscerated channel catfish and the smallest were in largemouth bass fillets. Polychlorinated biphenyl and selenium concentrations from analyses of this study were large enough to prompt the Texas State Department of Health to issue a fish-possession ban for Mountain Creek Lake in 1996.Suspended sediments in stormwater at the lagoon outfalls and at sites on Cottonwood Creek were sampled and analyzed for major and trace elements, polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls. The suspended sediments from the outfalls contained about the same mixture of heavy metals and organic compounds, in elevated concentrations compared to reference sites, as bottom sediments from the lagoons and surficial bottom sediments in Cottonwood Bay.Diagnostic ratios of polycyclic aromatic hydrocarbons indicate that uncombusted fuel sources contribute to older sediments and that pyrogenic sources of polycyclic aromatic hydrocarbons dominate recently deposited sediments in Cottonwood Bay and along the Air Station shoreline.

Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Compounds and their Ions. 6; Polycyclic Aromatic Nitrogen Heterocycles

NASA Technical Reports Server (NTRS)

Mattioda, A. L.; Hudgins, Douglas M.; Bauschlicher, C. W., Jr.; Rosi, M.; Allamandola, L. J.; DeVincenzi, D. (Technical Monitor)

2002-01-01

The matrix-isolation technique has been employed to measure the mid-infrared spectra of several polycyclic aromatic nitrogen heterocycles in both neutral and cationic forms. The species studied include: 7,8 benzoquinoline (C13H9N); 2-azapyrene (C15H9N); 1- and 2-azabenz(a)anthracene (C17H11N); and 1-, 2-, and 4-azachrysene (also C17H11N). The experimentally measured band frequencies and intensities for each molecule are tabulated and compared with their theoretically calculated values computed using density functional theory at the B3LYP/4-31G level. The overall agreement between experiment and theory is quite good, in keeping with previous investigations involving the parent aromatic hydrocarbons. Several interesting spectroscopic trends are found to accompany nitrogen substitution into the aromatic framework of these compounds. First, for the neutral species, the nitrogen atom produces a significant increase in the total integrated infrared intensity across the 1600 - 1100/cm region and plays an essential role in the molecular vibration that underlies an uncharacteristically intense, discrete feature that is observed near 1400/cm in the spectra of 7,8 benzoquinoline, 1-azabenz(a)anthracene, and 4-azachrysene. The origin of this enhanced infrared activity and the nature of the new 1400/cm vibrational mode are explored. Finally, in contrast to the parent hydrocarbon species, these aromatic nitrogen heterocycles possess a significant permanent dipole moment. Consequently, these dipole moments and the rotational constants are reported for these species in their neutral and ionized forms.

Atmospheric pressure solid analysis probe coupled to quadrupole-time of flight mass spectrometry as a tool for screening and semi-quantitative approach of polycyclic aromatic hydrocarbons, nitro-polycyclic aromatic hydrocarbons and oxo-polycyclic aromatic hydrocarbons in complex matrices.

PubMed

Carrizo, Daniel; Domeño, Celia; Nerín, Isabel; Alfaro, Pilar; Nerín, Cristina

2015-01-01

A new screening and semi-quantitative approach has been developed for direct analysis of polycyclic aromatic hydrocarbons (PAHs) and their nitro and oxo derivatives in environmental and biological matrices using atmospheric pressure solid analysis probe (ASAP) quadrupole-time of flight mass spectrometry (Q-TOF-MS). The instrumental parameters were optimized for the analysis of all these compounds, without previous sample treatment, in soil, motor oil, atmospheric particles (ashes) and biological samples such as urine and saliva of smokers and non-smokers. Ion source parameters in the MS were found to be the key parameters, with little variation within PAHs families. The optimized corona current was 4 µA, sample cone voltage 80 V for PAHs, nitro-PAHs and oxo-PAHs, while the desolvation temperatures varied from 300°C to 500°C. The analytical method performance was checked using a certified reference material. Two deuterated compounds were used as internal standards for semi-quantitative purposes together with the pure individual standard for each compound and the corresponding calibration plot. The compounds nitro PAH 9-nitroanthracene and oxo-PAH 1,4-naphthalenedione, were found in saliva and urine in a range below 1 µg/g while the range of PAHs in these samples was below 2 µg/g. Environmental samples provided higher concentration of all pollutants than urine and saliva. Copyright © 2014 Elsevier B.V. All rights reserved.

Oxidation kinetics of polycyclic aromatic hydrocarbons by permanganate.

PubMed

Forsey, Steven P; Thomson, Neil R; Barker, James F

2010-04-01

The reactivity of permanganate towards polycyclic aromatics hydrocarbons (PAHs) is well known but little kinetic information is available. This study investigated the oxidation kinetics of a selected group of coal tar creosote compounds and alkylbenzenes in water using permanganate, and the correlation between compound reactivity and physical/chemical properties. The oxidation of naphthalene, phenanthrene, chrysene, 1-methylnaphthalene, 2-methylnaphthalene, acenaphthene, fluorene, carbazole isopropylbenzene, ethylbenzene and methylbenzene closely followed pseudo first-order reaction kinetics. The oxidation of pyrene was initially very rapid and did not follow pseudo first-order kinetics at early times. Fluoranthene was only partially oxidized and the oxidation of anthracene was too fast to be captured. Biphenyl, dibenzofuran, benzene and tert-butylbenzene were non-reactive under the study conditions. The oxidation rate was shown to increase with increasing number of polycyclic rings because less energy is required to overcome the aromatic character of a polycyclic ring than is required for benzene. Thus the rate of oxidation increased in the series naphthalene

Groundwater contamination by polycyclic aromatic hydrocarbon due to diesel spill from a telecom base station in a Nigerian City: assessment of human health risk exposure.

PubMed

Ugochukwu, Uzochukwu Cornelius; Ochonogor, Alfred

2018-03-26

Diesel pollution of groundwater poses great threat to public health, mainly as a result of the constituent polycyclic aromatic hydrocarbons (PAHs). In this study, the human health risk exposure to polycyclic aromatic hydrocarbons (PAHs) in diesel contaminated groundwater used by several families at Ring Road, Jos, Nigeria (as caused by diesel spill from a telecom base station) was assessed. Prior to the groundwater being treated, the residents were using the water after scooping off the visible diesel sheen for purposes of cooking, washing, and bathing. Until this study, it is not clear whether the groundwater contamination had resulted in sub-chronic exposure of the residents using the water to polycyclic aromatic hydrocarbons (PAHs) to the extent of the PAHs posing a health risk. The diesel contaminated groundwater and uncontaminated nearby groundwater (control) were collected and analyzed for PAHs using gas chromatography-mass spectrometry (GC-MS). The dosage of the dermal and oral ingestion entry routes of PAHs was determined. The estimation of the non-carcinogenic health risk was via hazard quotients (HQ) and the associated hazard index (HI), while the estimation of the carcinogenic health risk was via lifetime cancer risks (LCR) and the associated risk index (RI). Obtained results indicate that the exposure of the residents to the PAHs may have made them susceptible to the risk of non-carcinogenic health effects of benzo(a)pyrene and the carcinogenic health effects of benzo(a)anthracene and benzo(a)pyrene.

Influence of Cadmium and Mercury on Activities of Ligninolytic Enzymes and Degradation of Polycyclic Aromatic Hydrocarbons by Pleurotus ostreatus in Soil

PubMed Central

Baldrian, Petr; in der Wiesche, Carsten; Gabriel, Jiří; Nerud, František; Zadražil, František

2000-01-01

The white-rot fungus Pleurotus ostreatus was able to degrade the polycyclic aromatic hydrocarbons (PAHs) benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, and benzo[ghi]perylene in nonsterile soil both in the presence and in the absence of cadmium and mercury. During 15 weeks of incubation, recovery of individual compounds was 16 to 69% in soil without additional metal. While soil microflora contributed mostly to degradation of pyrene (82%) and benzo[a]anthracene (41%), the fungus enhanced the disappearance of less-soluble polycyclic aromatic compounds containing five or six aromatic rings. Although the heavy metals in the soil affected the activity of ligninolytic enzymes produced by the fungus (laccase and Mn-dependent peroxidase), no decrease in PAH degradation was found in soil containing Cd or Hg at 10 to 100 ppm. In the presence of cadmium at 500 ppm in soil, degradation of PAHs by soil microflora was not affected whereas the contribution of fungus was negligible, probably due to the absence of Mn-dependent peroxidase activity. In the presence of Hg at 50 to 100 ppm or Cd at 100 to 500 ppm, the extent of soil colonization by the fungus was limited. PMID:10831426

Study of carbon nanotube-rich impedimetric recognition electrode for ultra-low determination of polycyclic aromatic hydrocarbons in water.

PubMed

Muñoz, Jose; Navarro-Senent, Cristina; Crivillers, Nuria; Mas-Torrent, Marta

2018-04-14

Carbon nanotubes (CNTs) have been studied as an electrochemical recognition element for the impedimetric determination of priority polycyclic aromatic hydrocarbons (PAHs) in water, using hexocyanoferrate as a redox probe. For this goal, an indium tin oxide (ITO) electrode functionalized with a silane-based self-assembled monolayer carrying CNTs has been engineered. The electroanalytical method, which is similar to an antibody-antigen assay, is straightforward and exploits the high CNT-PAH affinity obtained via π-interactions. After optimizing the experimental conditions, the resulting CNT-based impedimetric recognition platform exhibits ultra-low detection limits (1.75 ± 0.04 ng·L -1 ) for the sum of PAHs tested, which was also validated by using a certified reference PAH mixture. Graphical abstract Schematic of an indium-tin-oxide (ITO) electrode functionalized with a silane-based self-assembled monolayer carrying carbon nanotubes (CNTs) as a recognition platform for the ultra-low determination of total polycyclic aromatic hydrocarbons (PAHs) in water via π-interactions using Electrochemical Impedance Spectroscopy (EIS).

Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Compounds and Their Ions. 7; Phenazine, a Dual Substituted Polycyclic Aromatic Nitrogen Heterocycle

NASA Technical Reports Server (NTRS)

Mattioda, A. L.; Hudgins, D. M.; Bauschlicher, C. W., Jr.; Allamandola, L. J.

2004-01-01

The matrix-isolation technique has been employed to measure the mid-infrared spectra of phenazine (C12H8N2), a dual substituted Polycyclic Aromatic Nitrogen Heterocycle (PANH), in the neutral, cationic and anionic forms. The experimentally measured band frequencies and intensities are tabulated and compared with their calculated values as well as those of the non-substituted parent molecule, anthracene. The theoretical band positions and intensities were calculated using both the 3-31 G as well as the larger 6-3lG* Basis Sets. A comparison of the results can be found in the tables. The spectroscopic properties of phenazine and its cation are similar to those observed in mono-substituted PANHs, with one exception. The presence of a second nitrogen atom results in an additional enhancement of the cation's total integrated intensity, for the 1500-1000 cm(sup -1) (6.7 to 10 micron) region, over that observed for a mono-substituted PANH cation. The significance of this enhancement and the astrobiological implications of these results are discussed.

Separation of {sup 32}P-postlabeled DNA adducts of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons by HPLC

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

King, L.C.; Gallagher, J.E.; Lewtas, J.

The {sup 32}P-postlabeling assay, thin-layer chromatography, and reverse-phase high-pressure liquid chromatography (HPLC) were used to separate DNA adducts formed from 10 polycyclic aromatic hydrocarbons (PAHs) and 6 nitrated polycyclic aromatic hydrocarbons (NO{sub 2}-PAHs). The PAHs included benzo[j]fluoranthene, benzo[k]fluoranthene, indeno[1,2,3-cd]pyrene, benzo[a]pyrene, chrysene, 6-methylchrysene, 5-methylchrysene, and benz[a]anthracene. The NO{sub 2}-PAHs included 1-nitropyrene, 2-nitrofluoranthene, 3-nitrofluoranthene, 1,6-dinitropyrene, 1,3-dinitropyrene, and 1,8-dinitropyrene. Separation of seven of the major PAH-DNA adducts was achieved by an initial PAH HPLC gradient system. The major NO{sub 2}-PAH-DNA adducts were not all separated from each other using the initial PAH HPLC gradient but were clearly separated from the PAH-DNA adducts. Amore » second NO{sub 2}-PAH HPLC gradient system was developed to separate NO{sub 2}-PAH-DNA adducts following one-dimensional TLC and HPLC analysis. HPLC profiles of NO{sub 2}-PAH-DNA adducts were compared using both adduct enhancement versions of the {sup 32}P-postlabeling assay to evaluate the use of this technique on HPLC to screen for the presence of NO{sub 2}-PAH-DNA adducts. To demonstrate the application of these separation methods to a complex mixture of DNA adducts, the chromatographic mobilities of the {sup 32}P-postlabeled DNA adduct standards (PAHs and NO{sub 2}-PAHs) were compared with those produced by a complex mixture of polycyclic organic matter (POM) extracted from diesel emission particles. The diesel-derived adducts did not elute with the identical retention time of any of the PAH or NO{sub 2}-PAH standards used in this study. HPLC analyses of the NO{sub 2}-PAH-derived adducts (butanol extracted) revealed the presence of multiple DNA adducts.« less

Docking and QSAR comparative studies of polycyclic aromatic hydrocarbons and other procarcinogen interactions with cytochromes P450 1A1 and 1B1.

PubMed

Gonzalez, J; Marchand-Geneste, N; Giraudel, J L; Shimada, T

2012-01-01

To obtain chemical clues on the process of bioactivation by cytochromes P450 1A1 and 1B1, some QSAR studies were carried out based on cellular experiments of the metabolic activation of polycyclic aromatic hydrocarbons and heterocyclic aromatic compounds by those enzymes. Firstly, the 3D structures of cytochromes 1A1 and 1B1 were built using homology modelling with a cytochrome 1A2 template. Using these structures, 32 ligands including heterocyclic aromatic compounds, polycyclic aromatic hydrocarbons and corresponding diols, were docked with LigandFit and CDOCKER algorithms. Binding mode analysis highlighted the importance of hydrophobic interactions and the hydrogen bonding network between cytochrome amino acids and docked molecules. Finally, for each enzyme, multilinear regression and artificial neural network QSAR models were developed and compared. These statistical models highlighted the importance of electronic, structural and energetic descriptors in metabolic activation process, and could be used for virtual screening of ligand databases. In the case of P450 1A1, the best model was obtained with artificial neural network analysis and gave an r (2) of 0.66 and an external prediction [Formula: see text] of 0.73. Concerning P450 1B1, artificial neural network analysis gave a much more robust model, associated with an r (2) value of 0.73 and an external prediction [Formula: see text] of 0.59.

Challenges in tracing the fate and effects of atmospheric polycyclic aromatic hydrocarbon deposition in vascular plants.

PubMed

Desalme, Dorine; Binet, Philippe; Chiapusio, Geneviève

2013-05-07

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants that raise environmental concerns because of their toxicity. Their accumulation in vascular plants conditions harmful consequences to human health because of their position in the food chain. Consequently, understanding how atmospheric PAHs are taken up in plant tissues is crucial for risk assessment. In this review we synthesize current knowledge about PAH atmospheric deposition, accumulation in both gymnosperms and angiosperms, mechanisms of transfer, and ecological and physiological effects. PAHs emitted in the atmosphere partition between gas and particulate phases and undergo atmospheric deposition on shoots and soil. Most PAH concentration data from vascular plant leaves suggest that contamination occurs by both direct (air-leaf) and indirect (air-soil-root) pathways. Experimental studies demonstrate that PAHs affect plant growth, interfering with plant carbon allocation and root symbioses. Photosynthesis remains the most studied physiological process affected by PAHs. Among scientific challenges, identifying specific physiological transfer mechanisms and improving the understanding of plant-symbiont interactions in relation to PAH pollution remain pivotal for both fundamental and applied environmental sciences.

Measurement of polycyclic aromatic hydrocarbon (PAHs) in interplanetary dust particles

NASA Technical Reports Server (NTRS)

Clemett, S. J.; Maechling, C. R.; Zare, R. N.; Swan, P. D.; Walker, R. M.

1993-01-01

We report here the first definitive measurements of specific organic molecules (polycyclic aromatic hydrocarbons (PAH's)) in interplanetary dust particles (IDP's). An improved version of the microbeam-two-step laser mass spectrometer was used for the analysis. Two IDP's gave similar mass spectra showing an abundance of PAH's. Control samples, including particles of probable terrestrial origin from the same stratospheric collector, gave either null results or quite different spectra. We conclude that the PAH's are probably indigenous to the IDP's and are not terrestrial contaminants. The instrument used to study the particles is a two-step laser mass spectrometer. Constituent neutral molecules of the sample are first desorbed with a pulsed infrared laser beam focussed to 40 micrometers. In the second step, PAH's in the desorbed plume are preferentially ionized by a pulsed UV laser beam. Resulting ions produced by resonant absorption are extracted into a reflectron time-of-flight mass spectrometer. This instrument has high spatial resolution, high ion transmission, unlimited mass range, and multichannel detection of all ion masses from a single laser shot.

Polycyclic aromatic hydrocarbons and PAH-related DNA adducts.

PubMed

Ewa, Błaszczyk; Danuta, Mielżyńska-Švach

2017-08-01

Investigations on the impact of chemicals on the environment and human health have led to the development of an exposome concept. The exposome refers to the totality of exposures received by a person during life, including exposures to life-style factors, from the prenatal period to death. The exposure to genotoxic chemicals and their reactive metabolites can induce chemical modifications of DNA, such as, for example, DNA adducts, which have been extensively studied and which play a key role in chemically induced carcinogenesis. Development of different methods for the identification of DNA adducts has led to adopting DNA adductomic approaches. The ability to simultaneously detect multiple PAH-derived DNA adducts may allow for the improved assessment of exposure, and offer a mechanistic insight into the carcinogenic process following exposure to PAH mixtures. The major advantage of measuring chemical-specific DNA adducts is the assessment of a biologically effective dose. This review provides information about the occurrence of the polycyclic aromatic hydrocarbons (PAHs) and their influence on human exposure and biological effects, including PAH-derived DNA adduct formation and repair processes. Selected methods used for determination of DNA adducts have been presented.

Mapping polycyclic aromatic hydrocarbon and total toxicity equivalent soil concentrations by visible and near-infrared spectroscopy.

PubMed

Okparanma, Reuben N; Coulon, Frederic; Mayr, Thomas; Mouazen, Abdul M

2014-09-01

In this study, we used data from spectroscopic models based on visible and near-infrared (vis-NIR; 350-2500 nm) diffuse reflectance spectroscopy to develop soil maps of polycyclic aromatic hydrocarbons (PAHs) and total toxicity equivalent concentrations (TTEC) of the PAH mixture. The TTEC maps were then used for hazard assessment of three petroleum release sites in the Niger Delta province of Nigeria (5.317°N, 6.467°E). As the paired t-test revealed, there were non-significant (p > 0.05) differences between soil maps of PAH and TTEC developed with chemically measured and vis-NIR-predicted data. Comparison maps of PAH showed a slight to moderate agreement between measured and predicted data (Kappa coefficient = 0.19-0.56). Using proposed generic assessment criteria, hazard assessment showed that the degree of action for site-specific risk assessment and/or remediation is similar for both measurement methods. This demonstrates that the vis-NIR method may be useful for monitoring hydrocarbon contamination in a petroleum release site. Copyright © 2014 Elsevier Ltd. All rights reserved.

Semi-empirical estimation of organic compound fugacity ratios at environmentally relevant system temperatures.

PubMed

van Noort, Paul C M

2009-06-01

Fugacity ratios of organic compounds are used to calculate (subcooled) liquid properties, such as solubility or vapour pressure, from solid properties and vice versa. They can be calculated from the entropy of fusion, the melting temperature, and heat capacity data for the solid and the liquid. For many organic compounds, values for the fusion entropy are lacking. Heat capacity data are even scarcer. In the present study, semi-empirical compound class specific equations were derived to estimate fugacity ratios from molecular weight and melting temperature for polycyclic aromatic hydrocarbons and polychlorinated benzenes, biphenyls, dibenzo[p]dioxins and dibenzofurans. These equations estimate fugacity ratios with an average standard error of about 0.05 log units. In addition, for compounds with known fusion entropy values, a general semi-empirical correction equation based on molecular weight and melting temperature was derived for estimation of the contribution of heat capacity differences to the fugacity ratio. This equation estimates the heat capacity contribution correction factor with an average standard error of 0.02 log units for polycyclic aromatic hydrocarbons, polychlorinated benzenes, biphenyls, dibenzo[p]dioxins and dibenzofurans.

Use of semipermeable membrane devices for in situ monitoring of polycyclic aromatic hydrocarbons in aquatic environments

USGS Publications Warehouse

Lebo, Jon A.; Zajicek, James L.; Huckins, James N.; Petty, Jimmie D.; Peterman, Paul H.

1992-01-01

A method is given for the recovery, cleanup, and analysis of polycyclic aromatic hydrocarbons (PAHs) that have been sequestered in SPMDs (semipermeable membrane devices). SPMDs are polymeric membranes enclosing lipids, and mimic the bioconcentration process of aquatic animals. SPMDs are used as passive, in situ monitors of contamination by organic pollutants of aquatic environments. The method reported here includes dialytic recovery of the PAHs, cleanup of the dialysates using size exclusion, adsorption, and argentation chromatographic modules in tandem, then analysis by gas chromatography with photoionization or mass spectrometric detection. The method is demonstrated to overcome the presence of a variety of environmental co-contaminants and other potential interferents in the dialysates. A field application is also demonstrated in which SPMDs are used to monitor PAH contamination in an urban creek. Approaches to the use of SPMD data to calculate aqueous concentrations of PAHs are discussed. The use of SPMDs in combination with the complementary, PAH-specific cleanup procedure provides a unique approach to the analysis of PAH residues in the aquatic environment.

Health risks of polycyclic aromatic hydrocarbons via fish consumption in Haimen bay (China), downstream of an e-waste recycling site (Guiyu).

PubMed

Shi, Jingchun; Zheng, Gene Jin-Shu; Wong, Ming-Hung; Liang, Hong; Li, Yuelin; Wu, Yinglin; Li, Ping; Liu, Wenhua

2016-05-01

Guiyu, China has been one of the largest e-waste recycling sites of the world for more than 20 years. Abundant data show that local dwellers there suffered from severe health risks from e-waste contaminants. In this study, polycyclic aromatic hydrocarbons (PAHs) were used as candidates to test the contamination levels and their possible adverse effects on residents in Haimen Bay, the estuary of Lian River (less than 30km from Guiyu), which has been totally neglected. The concentrations of 16PAHs were determined in collected marine fish with a median ΣPAH concentration of 1478ng/g (wet weight), and the contamination may be mainly influenced by Lian River runoff, specifically from Guiyu. The lifetime excess cancer risk for local dwellers was much higher than the serious risk level (10(-4)). More seriously, outflows of PAHs from the e-waste recycling site (Guiyu) seemed to exert health risks of a much larger scale of population downstream. Copyright © 2016 Elsevier Inc. All rights reserved.

A High Throughput Method for Measuring Polycyclic Aromatic Hydrocarbons in Seafood Using QuEChERS Extraction and SBSE.

PubMed

Pfannkoch, Edward A; Stuff, John R; Whitecavage, Jacqueline A; Blevins, John M; Seely, Kathryn A; Moran, Jeffery H

2015-01-01

National Oceanic and Atmospheric Administration (NOAA) Method NMFS-NWFSC-59 2004 is currently used to quantitatively analyze seafood for polycyclic aromatic hydrocarbon (PAH) contamination, especially following events such as the Deepwater Horizon oil rig explosion that released millions of barrels of crude oil into the Gulf of Mexico. This method has limited throughput capacity; hence, alternative methods are necessary to meet analytical demands after such events. Stir bar sorptive extraction (SBSE) is an effective technique to extract trace PAHs in water and the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction strategy effectively extracts PAHs from complex food matrices. This study uses SBSE to concentrate PAHs and eliminate matrix interference from QuEChERS extracts of seafood, specifically oysters, fish, and shrimp. This method provides acceptable recovery (65-138%) linear calibrations and is sensitive (LOD = 0.02 ppb, LOQ = 0.06 ppb) while providing higher throughput and maintaining equivalency between NOAA 2004 as determined by analysis of NIST SRM 1974b mussel tissue.

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

NASA Astrophysics Data System (ADS)

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

2017-03-01

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

Theoretical and experimental study of polycyclic aromatic compounds as β-tubulin inhibitors.

PubMed

Olazarán, Fabian E; García-Pérez, Carlos A; Bandyopadhyay, Debasish; Balderas-Rentería, Isaias; Reyes-Figueroa, Angel D; Henschke, Lars; Rivera, Gildardo

2017-03-01

In this work, through a docking analysis of compounds from the ZINC chemical library on human β-tubulin using high performance computer cluster, we report new polycyclic aromatic compounds that bind with high energy on the colchicine binding site of β-tubulin, suggesting three new key amino acids. However, molecular dynamic analysis showed low stability in the interaction between ligand and receptor. Results were confirmed experimentally in in vitro and in vivo models that suggest that molecular dynamics simulation is the best option to find new potential β-tubulin inhibitors. Graphical abstract Bennett's acceptance ratio (BAR) method.

Polycyclic aromatic hydrocarbons residues in sandstorm depositions in Beijing, China

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

Fu, S.; Li, K.; Xia, X.J.

2009-02-15

This study was conducted to determine the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in sandstorm depositions in Beijing, China. The PAH concentrations in 13 samples collected in Beijing ranged from 0.18 to 3.52 {mu} g g{sup -1}. Analysis of the sources of contamination revealed that the PAHs were derived from a coal combustion source, although various effects of traffic emissions were also observed. Furthermore, the PAH levels in Beijing tended to be higher in the southeast. Finally, the Nemerow composite index revealed that the degree of pollution in the sandstorm depositions varied widely among sampling sites.

Synthesis of polycyclic aromatic hydrocarbon-protein conjugates for preparation and immunoassay of antibodies.

PubMed

Glushkov, Andrey N; Kostyanko, Mikhail V; Cherno, Sergey V; Vasilchenko, Ilya L

2002-04-01

The method is described dealing with the synthesis of conjugates protein-polycyclic aromatic hydrocarbons (PAHs), highly soluble in water, stable without special stabilizers and containing the minimum quantity of cross-linked products. The reaction of protein with PAH containing an aldehyde group, has been carried out in an alkaline solution, and stabilization of the conjugate has been achieved by reduction with sodium borohydride in the presence of a compound blocking the formation of an insoluble polymeric fraction. The efficiency of synthesized conjugates for the induction and immunoassay of Abs to PAH for benzo[a]pyrene is shown.

A unifying picture of gas-phase formation and growth of PAH (Polycyclic Aromatic Hydrocarbons), soot, diamond and graphite

NASA Technical Reports Server (NTRS)

Frenklach, Michael

1990-01-01

A variety of seemingly different carbon formation processes -- polycyclic aromatic hydrocarbons and diamond in the interstellar medium, soot in hydrocarbon flames, graphite and diamond in plasma-assisted-chemical vapor deposition reactors -- may all have closely related underlying chemical reaction mechanisms. Two distinct mechanisms for gas-phase carbon growth are discussed. At high temperatures it proceeds via the formation of carbon clusters. At lower temperatures it follows a polymerization-type kinetic sequence of chemical reactions of acetylene addition to a radical, and reactivation of the resultant species through H-abstraction by a hydrogen atom.

Polycyclic aromatic hydrocarbons in stellar medium

NASA Astrophysics Data System (ADS)

Rastogi, Shantanu

2005-06-01

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.

Diversity of organotrophic bacteria, activity of dehydrogenases and urease as well as seed germination and root growth Lepidium sativum, Sorghum saccharatum and Sinapis alba under the influence of polycyclic aromatic hydrocarbons.

PubMed

Lipińska, Aneta; Wyszkowska, Jadwiga; Kucharski, Jan

2015-12-01

Polycyclic aromatic hydrocarbons are organic compounds with highly toxic, carcinogenic, and mutagenic properties, which adversely affect the basic biological parameters of the soil, including the count of microorganisms, and the enzymatic activity. In addition to disturbances to the biological activity of the soil, PAHs may also exhibit toxic effects on plants. In view of the above, the study involved testing aimed at the determination of the effects of polycyclic aromatic hydrocarbons in a form of naphthalene, phenanthrene, anthracene and pyrene on the count, colony development (CD) index, ecophysiological (EP) diversity index of organotrophic bacteria, and the activity of soil dehydrogenases and soil urease. Moreover, an attempt was made to determine the soil's resistance based on the activity of the above-listed enzymes, and the effect of polycyclic aromatic hydrocarbons on seed germination and root growth was assessed by Lepidium sativum, Sorghum saccharatum, and Sinapis alba. In addition, the species of bacteria found in a soil subjected to strong pressure of polycyclic aromatic hydrocarbons were isolated. The experiment was performed in a laboratory on samples of loamy sand. Polycyclic aromatic hydrocarbons were introduced into the soil in an amount of 0, 1000, 2000, and 4000 mg kg(-1) of soil dry matter. Germination and growth of cress (L. sativum), white mustard (S. alba), and sweet sorghum (S. saccharatum) were determined using Phytotoxkit tests. It was found that the tested PAHs increased the average colony counts of organotrophic soil bacteria; pyrene did so to the greatest extent (2.2-fold relative to non-contaminated soil), phenanthrene to the smallest extent (1.4-fold relative to non-contaminated soil). None of the PAHs changed the value of the bacterial colony development (CD) index, while anthracene and pyrene increased the value of the eco-physiological (EP) diversity indicator. PAHs lowered the activity of the tested enzymes. The activity of dehydrogenases was dependent on a greater extent by the type of hydrocarbon (54.56%) rather than by the dose (10.64%), while for the activity of urease, it was the opposite. The greater extent was dependent on dose (95.42%) rather than by type (0.21%). Dehydrogenases are characterised by greater resistance to the action of PAHs than urease. Based on seed germination and root growth, it has shown that S. alba is best suited, being the most vulnerable plant, while S. saccharatum is the least suited. Subjecting a soil to strong pressure of PAHs leads to disturbances to the biological parameters of the soil, seed germination, and root growth L. sativum, S. saccharatum, and S. alba.

Distributions of Polycyclic Aromatic Hydrocarbons, Aromatic Ketones, Carboxylic Acids, and Trace Metals in Arctic Aerosols: Long-Range Atmospheric Transport, Photochemical Degradation/Production at Polar Sunrise.

PubMed

Singh, Dharmendra Kumar; Kawamura, Kimitaka; Yanase, Ayako; Barrie, Leonard A

2017-08-15

The distributions, correlations, and source apportionment of aromatic acids, aromatic ketones, polycyclic aromatic hydrocarbons (PAHs), and trace metals were studied in Canadian high Arctic aerosols. Nineteen PAHs including minor sulfur-containing heterocyclic PAH (dibenzothiophene) and major 6 carcinogenic PAHs were detected with a high proportion of fluoranthene followed by benzo[k]fluoranthene, pyrene, and chrysene. However, in the sunlit period of spring, their concentrations significantly declined likely due to photochemical decomposition. During the polar sunrise from mid-March to mid-April, benzo[a]pyrene to benzo[e]pyrene ratios significantly dropped, and the ratios diminished further from late April to May onward. These results suggest that PAHs transported over the Arctic are subjected to strong photochemical degradation at polar sunrise. Although aromatic ketones decreased in spring, concentrations of some aromatic acids such as benzoic and phthalic acids increased during the course of polar sunrise, suggesting that aromatic hydrocarbons are oxidized to result in aromatic acids. However, PAHs do not act as the major source for low molecular weight (LMW) diacids such as oxalic acid that are largely formed at polar sunrise in the arctic atmosphere because PAHs are 1 to 2 orders of magnitude less abundant than LMW diacids. Correlations of trace metals with organics, their sources, and the possible role of trace transition metals are explained.

MODELING THE BINDING OF THE METABOLITES OF SOME POLYCYCLIC AROMTIC HYDROCARBONS TO THE LIGAND BINDING DOMAIN OF THE ESTROGEN RECEPTOR

EPA Science Inventory

Modeling the binding of the metabolites of some Polycyclic Aromatic Hydrocarbons to the ligand binding domain of the estrogen receptor
James Rabinowitz, Stephen Little, Katrina Brown, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC; Un...

Using urinary biomarkers to evaluate polycyclic hydrocarbon exposures in 126 preschool children in Ohio

EPA Science Inventory

Limited data exist on exposures of young children to polycyclic aromatic hydrocarbons (PAHs) in the United States (US). The urinary metabolite of pyrene, 1-hydroxypyrene (1-OHPyr), is widely used as a biomarker of total PAH exposure. Our objectives were to quantify urinary 1-OHPy...

Biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons under anaerobic conditions: Overview of studies, proposed pathways and future perspectives.

PubMed

Nzila, Alexis

2018-05-07

The biodegradation of low- and high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) (LWM-PAHs and HMW-PAHs, respectively) has been studied extensively under aerobic conditions. Molecular O 2 plays 2 critical roles in this biodegradation process. O 2 activates the aromatic rings through hydroxylation prior to ring opening and serves as a terminal electron acceptor (TEA). However, several microorganisms have devised ways of activating aromatic rings, leading to ring opening (and thus biodegradation) when TEAs other than O 2 are used (under anoxic conditions). These microorganisms belong to the sulfate-, nitrate-, and metal-ion-reducing bacteria and the methanogens. Although the anaerobic biodegradation of monocyclic aromatic hydrocarbons and LWM-PAH naphthalene have been studied, little information is available about the biodegradation of HMW-PAHs. This manuscript reviews studies of the anaerobic biodegradation of HMW-PAHs and identifies gaps that limit both our understanding and the efficiency of this biodegradation process. Strategies that can be employed to overcome these limitations are also discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ultraviolet Irradiation of Naphthalene in H2O Ice: Implications for Meteorites and Biogenesis

NASA Technical Reports Server (NTRS)

Bernstein, Max P.; Dworkin, Jason; Sandford, Scott A.; Allamandola, Louis J.; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

The polycyclic aromatic hydrocarbon (PAH) naphthalene was exposed to ultraviolet radiation in H2O ice under astrophysical conditions, and the products were analyzed using infrared spectroscopy and high performance liquid chromatography. As we found in our earlier studies on the photoprocessing of coronene in H2O ice, aromatic alcohols and ketones (quinones) were formed. The regiochemistry of the reactions is described and leads to specific predictions of the relative abundances of various oxidized naphthalenes that should exist in meteorites if interstellar ice photochemistry influenced their aromatic inventory. Since oxidized PAHs are present in carbon-rich meteorites and interplanetary dust particles (IDPs), and ubiquitous in and fundamental to biochemistry, the delivery of such extraterrestrial molecules to the early Earth may have played a role in the origin and evolution of life.

Suspect screening of OH-PAHs and non-target screening of other organic compounds in wood smoke particles using HR-Orbitrap-MS.

PubMed

Avagyan, Rozanna; Åberg, Magnus; Westerholm, Roger

2016-11-01

Wood combustion has been shown to contribute significantly to emissions of polycyclic aromatic hydrocarbons and hydroxylated polycyclic aromatic hydrocarbons, compounds with toxic and carcinogenic properties. However, only a small number of hydroxylated polycyclic aromatic hydrocarbons have been determined in particles from wood combustion, usually compounds with available reference standards. In this present study, suspect and non-target screening strategies were applied to characterize the wood smoke particles from four different wood types and two combustion conditions with respect to hydroxylated polycyclic aromatic hydrocarbons and other organic compounds. In the suspect screening, 32 peaks corresponding to 12 monohydroxylated masses were tentatively identified by elemental composition assignments and matching of isotopic pattern and fragments. More than one structure was suggested for most of the measured masses. Statistical analysis was performed on the non-target screening data in order to single out significant peaks having intensities that depend on the wood type and/or combustion condition. Significant peaks were found in both negative and positive ionization modes, with unique peaks for each wood type and combustion condition, as well as a combination of both factors. Furthermore, structural elucidation of some peaks was done by comparing the spectra in the samples with spectra found in the spectral databases. Six compounds were tentatively identified in positive ionization mode, and 19 in negative ionization mode. The results in this present study demonstrate that there are significant overall differences in the chemistry of wood smoke particles that depends on both the wood type and the combustion condition used. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation of polydimethylsiloxane/beta-cyclodextrin/divinylbenzene coated "dumbbell-shaped" stir bar and its application to the analysis of polycyclic aromatic hydrocarbons and polycyclic aromatic sulfur heterocycles compounds in lake water and soil by high performance liquid chromatography.

PubMed

Yu, Chunhe; Yao, Zhimin; Hu, Bin

2009-05-08

A "dumbbell-shaped" stir bar was proposed to prevent the friction loss of coating during the stirring process, and thus prolonged the lifetime of stir bars. The effects of the coating components, including polydimethylsiloxane (PDMS), beta-cyclodextrin (beta-CD) and divinylbenzene (DVB) were investigated according to an orthogonal experimental design, using three polycyclic aromatic hydrocarbons (PAHs) and four polycyclic aromatic sulfur heterocycles (PASHs) as model analytes. Four kinds of stir bars coated with PDMS, PDMS/beta-CD, PDMS/DVB and PDMS/beta-CD/DVB were prepared and their extraction efficiencies for the target compounds were compared. It was demonstrated that PDMS/beta-CD/DVB-coated stir bar showed the best affinity to the studied compounds. The preparation reproducibility of PDMS/beta-CD/DVB-coated stir bar ranged from 3.2% to 15.2% (n = 6) in one batch, and 5.2% to 13.4% (n = 6) among batches. The "dumbbell-shaped" stir bar could be used for about 40 times, which were 10 extractions more than a normal stir bar. The prepared PDMS/beta-CD/DVB-coated "dumbbell-shaped" stir bar was used for stir bar sorptive extraction (SBSE) of PAHs and PASHs and the desorbed solution was introduced into HPLC-UV for subsequent analysis. The limits of detection of the proposed method for seven target analytes ranged from 0.007 to 0.103 microg L(-1), the relative standard deviations were in the range of 6.3-12.9% (n = 6, c = 40 microg L(-1)), and the enrichment factors were 19-86. The proposed method was successfully applied to the analysis of seven target analytes in lake water and soil samples.

Source identification and seasonal variation of polycyclic aromatic hydrocarbons associated with atmospheric fine and coarse particles in the Metropolitan Area of Porto Alegre, RS, Brazil

NASA Astrophysics Data System (ADS)

Teixeira, Elba Calesso; Agudelo-Castañeda, Dayana M.; Fachel, Jandyra Maria Guimarães; Leal, Karen Alam; Garcia, Karine de Oliveira; Wiegand, Flavio

2012-11-01

The purpose of the present study was to evaluate the polycyclic aromatic hydrocarbons (PAHs) in fine (PM2.5) and coarse particles (PM2.5-10) in an urban and industrial area in the Metropolitan Area of Porto Alegre (MAPA), Brazil. Sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) were measured. Filters containing ambient air particulate were extracted with dichloromethane using Soxhlet. Extracts were later analyzed, for determining PAH concentrations, using a gaseous chromatograph coupled with a mass spectrometer (GC-MS). The polycyclic aromatic hydrocarbons (PAHs) were more concentrated in PM2.5 with an average of 70% of total PAHs in the MAPA. The target PAH apportionment among the main emission sources was carried out by diagnostic PAH concentration ratios, and principal component analysis (PCA). PAHs with higher molecular weight showed higher percentages in the fine particles in the MAPA. Based on the diagnostic ratios and PCA analysis, it may be concluded that the major contribution of PAHs was from vehicular sources (diesel and gasoline), especially in the PM2.5 fraction, as well as coal and wood burning. The winter/summer ratio in the PM2.5 and PM2.5-10 fractions in the MAPA was 3.1 and 1.8, respectively, revealing the seasonal variation of PAHs in the two fractions. The estimated toxicity equivalent factor (TEF), used to assess the contribution of the carcinogenic potency, confirms a significant presence of the moderately active carcinogenic PAHs BaP and DahA in the samples collected in the MAPA.

Magnetic ionic liquids as non-conventional extraction solvents for the determination of polycyclic aromatic hydrocarbons.

PubMed

Trujillo-Rodríguez, María J; Nacham, Omprakash; Clark, Kevin D; Pino, Verónica; Anderson, Jared L; Ayala, Juan H; Afonso, Ana M

2016-08-31

This work describes the applicability of magnetic ionic liquids (MILs) in the analytical determination of a group of heavy polycyclic aromatic hydrocarbons. Three different MILs, namely, benzyltrioctylammonium bromotrichloroferrate (III) (MIL A), methoxybenzyltrioctylammonium bromotrichloroferrate (III) (MIL B), and 1,12-di(3-benzylbenzimidazolium) dodecane bis[(trifluoromethyl)sulfonyl)]imide bromotrichloroferrate (III) (MIL C), were designed to exhibit hydrophobic properties, and their performance examined in a microextraction method for hydrophobic analytes. The magnet-assisted approach with these MILs was performed in combination with high performance liquid chromatography and fluorescence detection. The study of the extraction performance showed that MIL A was the most suitable solvent for the extraction of polycyclic aromatic hydrocarbons and under optimum conditions the fast extraction step required ∼20 μL of MIL A for 10 mL of aqueous sample, 24 mmol L(-1) NaOH, high ionic strength content of NaCl (25% (w/v)), 500 μL of acetone as dispersive solvent, and 5 min of vortex. The desorption step required the aid of an external magnetic field with a strong NdFeB magnet (the separation requires few seconds), two back-extraction steps for polycyclic aromatic hydrocarbons retained in the MIL droplet with n-hexane, evaporation and reconstitution with acetonitrile. The overall method presented limits of detection down to 5 ng L(-1), relative recoveries ranging from 91.5 to 119%, and inter-day reproducibility values (expressed as relative standard derivation) lower than 16.4% for a spiked level of 0.4 μg L(-1) (n = 9). The method was also applied for the analysis of real samples, including tap water, wastewater, and tea infusion. Copyright © 2016 Elsevier B.V. All rights reserved.

Emissions of particle-phase polycyclic aromatic hydrocarbons (PAHs) in the Fu Gui-shan Tunnel of Nanjing, China

NASA Astrophysics Data System (ADS)

Chen, Fei; Hu, Wei; Zhong, Qin

2013-04-01

Real-world vehicle emission factors for PM10 (particulate matter with aerodynamic diameter smaller than 10 μm) and particle-phase polycyclic aromatic hydrocarbons (PAHs) from mixed vehicles were quantified in the Fu Gui-shan Tunnel of Nanjing during summer and winter of 2010. Concentrations of PM10 and sixteen particle phase polycyclic aromatic hydrocarbons (PAHs) in the entrance and exit of the tunnel were studied. The results showed that the four most abundant particular phase polycyclic aromatic hydrocarbons (PAHs) of motor vehicle were benzo[ghi]perylene, benzo[k]fluoranthene, benz[a]anthracene and benzo[a]pyrene. The emission factors for PM10 and particle-phase PAHs were 687 mg veh- 1 km- 1 and 18.853 mg veh- 1 km- 1 in summer, 714 mg veh- 1 km- 1 and 20.374 mg veh- 1 km- 1 in winter. Higher particle-phase PAH emission factors were found to be associated with a high proportion of diesel-fueled vehicles (DV). The estimated PM10 emission factor of gasoline-fueled vehicles (GV) was 513 mg veh- 1 km- 1 and the value for DV was 914 mg veh- 1 km- 1, while EFDV of particulate PAH (31.290 mg veh- 1 km- 1) was nearly 4 times higher than EFGV (9.310 mg veh- 1 km- 1). The five highest emission factors of diesel-fueled vehicles (DV) were benzo[ghi]perylene, benzo[k]fluoranthene, Indeno[1,2,3-cd]pyrene, benz[a]anthracene and benzo[a]pyrene, which was similarly found in the gasoline-fueled vehicles (GV). The sum of these five emission factors accounted for ~ 69% of the total particle-phase PAH of DV and ~ 67% of GV.

Prenatal exposure to polycyclic aromatic hydrocarbons/aromatics, BDNF and child development

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

Perera, Frederica, E-mail: fpp1@columbia.edu; Columbia Center for Children's Environmental Health, Columbia University, 722 W. 168th St., New York, NY 10032; Phillips, David H.

Objectives: Within a New York City (NYC) birth cohort, we assessed the associations between polycyclic aromatic hydrocarbon (PAH) and other aromatic DNA adducts and brain derived neurotrophic factor (BDNF) concentrations in umbilical cord blood, and neurodevelopment at age 2 years and whether BDNF is a mediator of the associations between PAH/aromatic-DNA adducts and neurodevelopment. Methods: PAH/aromatic-DNA adduct concentrations in cord blood were measured in 505 children born to nonsmoking African-American and Dominican women residing in NYC, and a subset was assessed for neurodevelopment at 2 years using the Bayley Scales of Infant Development Mental Development Index (MDI). A spectrum ofmore » PAH/aromatic-DNA adducts was measured using the {sup 32}P-postlabeling assay; DNA adducts formed by benzo[a]pyrene (B[a]P), a representative PAH, were measured by High Performance Liquid Chromatography (HPLC)/fluorescence. BDNF mature protein in cord blood plasma was quantified by an ELISA. Multivariate regression analysis, adjusting for potential confounders, was conducted. Results: PAH/aromatic-DNA adduct concentration measured by postlabeling was inversely associated with BDNF concentration (p=0.02) and with MDI scores at 2 years (p=0.04). BDNF level was positively associated with MDI scores (p=0.003). Restricting to subjects having all three measures (PAH/aromatic-DNA adducts by postlabeling, MDI, and BDNF), results were similar but attenuated (p=0.13, p=0.05, p=0.01, respectively). Associations between B[a]P-DNA adducts and BDNF and B[a]P-DNA adducts and MDI at age 2 years were not significant. At age 3 years, the positive association of BDNF with MDI was not observed. Conclusions: The results at age 2 suggest that prenatal exposure to a spectrum of PAH/aromatic pollutants may adversely affect early neurodevelopment, in part by reducing BDNF levels during the fetal period. However, the same relationship was not seen at age 3. - Highlights: • Cord blood Polycyclic Aromatic Hydrocarbon (PAH)/aromatic-DNA adducts were assayed. • Brain Derived Neurotrophic Factor (BDNF) concentration was measured concurrently. • Associations between biomarkers and neurodevelopment at age 2 years were assessed. • Adduct level was inversely associated with BDNF concentration and neurodevelopment. • BDNF level was positively associated with neurodevelopment scores at age 2 years.« less

Deuterium enrichment of polycyclic aromatic hydrocarbons by photochemically induced exchange with deuterium-rich cosmic ices

NASA Technical Reports Server (NTRS)

Sandford, S. A.; Bernstein, M. P.; Allamandola, L. J.; Gillette, J. S.; Zare, R. N.

2000-01-01

The polycyclic aromatic hydrocarbon (PAH) coronene (C24H12) frozen in D2O ice in a ratio of less than 1 part in 500 rapidly exchanges its hydrogen atoms with the deuterium in the ice at interstellar temperatures and pressures when exposed to ultraviolet radiation. Exchange occurs via three different chemical processes: D atom addition, D atom exchange at oxidized edge sites, and D atom exchange at aromatic edge sites. Observed exchange rates for coronene (C24H12)-D2O and d12-coronene (C24D12)-H2O isotopic substitution experiments show that PAHs in interstellar ices could easily attain the D/H levels observed in meteorites. These results may have important consequences for the abundance of deuterium observed in aromatic materials in the interstellar medium and in meteorites. These exchange mechanisms produce deuteration in characteristic molecular locations on the PAHs that may distinguish them from previously postulated processes for D enrichment of PAHs.

One-shot K-region-selective annulative π-extension for nanographene synthesis and functionalization.

PubMed

Ozaki, Kyohei; Kawasumi, Katsuaki; Shibata, Mari; Ito, Hideto; Itami, Kenichiro

2015-02-16

The optoelectronic nature of two-dimensional sheets of sp(2)-hydridized carbons (for example, graphenes and nanographenes) can be dramatically altered and tuned by altering the degree of π-extension, shape, width and edge topology. Among various approaches to synthesize nanographenes with atom-by-atom precision, one-shot annulative π-extension (APEX) reactions of polycyclic aromatic hydrocarbons hold significant potential not only to achieve a 'growth from template' synthesis of nanographenes, but also to fine-tune the properties of nanographenes. Here we describe one-shot APEX reactions that occur at the K-region (convex armchair edge) of polycyclic aromatic hydrocarbons by the Pd(CH3CN)4(SbF6)2/o-chloranil catalytic system with silicon-bridged aromatics as π-extending agents. Density functional theory calculations suggest that the complete K-region selectivity stems from the olefinic (decreased aromatic) character of the K-region. The protocol is applicable to multiple APEX and sequential APEX reactions, to construct various nanographene structures in a rapid and programmable manner.

One-shot K-region-selective annulative π-extension for nanographene synthesis and functionalization

NASA Astrophysics Data System (ADS)

Ozaki, Kyohei; Kawasumi, Katsuaki; Shibata, Mari; Ito, Hideto; Itami, Kenichiro

2015-02-01

The optoelectronic nature of two-dimensional sheets of sp2-hydridized carbons (for example, graphenes and nanographenes) can be dramatically altered and tuned by altering the degree of π-extension, shape, width and edge topology. Among various approaches to synthesize nanographenes with atom-by-atom precision, one-shot annulative π-extension (APEX) reactions of polycyclic aromatic hydrocarbons hold significant potential not only to achieve a ‘growth from template’ synthesis of nanographenes, but also to fine-tune the properties of nanographenes. Here we describe one-shot APEX reactions that occur at the K-region (convex armchair edge) of polycyclic aromatic hydrocarbons by the Pd(CH3CN)4(SbF6)2/o-chloranil catalytic system with silicon-bridged aromatics as π-extending agents. Density functional theory calculations suggest that the complete K-region selectivity stems from the olefinic (decreased aromatic) character of the K-region. The protocol is applicable to multiple APEX and sequential APEX reactions, to construct various nanographene structures in a rapid and programmable manner.

Device for aqueous detection of nitro-aromatic compounds

DOEpatents

Reagen, W.K.; Schulz, A.L.; Ingram, J.C.; Lancaster, G.D.; Grey, A.E.

1994-04-26

This invention relates to a compact and portable detection apparatus for nitro-aromatic based chemical compounds, such as nitrotoluenes, dinitrotoluenes, and trinitrotoluene (TNT). The apparatus is based upon the use of fiber optics using filtered light. The preferred process of the invention relies upon a reflective chemical sensor and optical and electronic components to monitor a decrease in fluorescence when the nitro-aromatic molecules in aqueous solution combine and react with a fluorescent polycyclic aromatic compound. 4 figures.

Device for aqueous detection of nitro-aromatic compounds

DOEpatents

Reagen, William K.; Schulz, Amber L.; Ingram, Jani C.; Lancaster, Gregory D.; Grey, Alan E.

1994-01-01

This invention relates to a compact and portable detection apparatus for ro-aromatic based chemical compounds, such as nitrotoluenes, dinitrotoluenes, and trinitrotoluene (TNT). The apparatus is based upon the use of fiber optics using filtered light. The preferred process of the invention relies upon a reflective chemical sensor and optical and electronic components to monitor a decrease in fluorescence when the nitro-aromatic molecules in aqueous solution combine and react with a fluorescent polycyclic aromatic compound.

Natural Mediators in the Oxidation of Polycyclic Aromatic Hydrocarbons by Laccase Mediator Systems

PubMed Central

Johannes, Christian; Majcherczyk, Andrzej

2000-01-01

The oxidation of polycyclic aromatic compounds was studied in systems consisting of laccase from Trametes versicolor and so-called mediator compounds. The enzymatic oxidation of acenaphthene, acenaphthylene, anthracene, and fluorene was mediated by various laccase substrates (phenols and aromatic amines) or compounds produced and secreted by white rot fungi. The best natural mediators, such as phenol, aniline, 4-hydroxybenzoic acid, and 4-hydroxybenzyl alcohol were as efficient as the previously described synthetic compounds ABTS [2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)] and 1-hydroxybenzotriazole. The oxidation efficiency increased proportionally with the redox potentials of the phenolic mediators up to a maximum value of 0.9 V and decreased thereafter with redox potentials exceeding this value. Natural compounds such as methionine, cysteine, and reduced glutathione, containing sulfhydryl groups, were also active as mediator compounds. PMID:10653713

Catalytic hydrogenation rate of polycyclic aromatic hydrocarbons in supercritical carbon dioxide containing polymer-stabilized palladium nanoparticles.

PubMed

Liao, Weisheng; Liu, Hsin-Wang; Chen, Hsing-Jung; Chang, Wen-Yen; Chiu, Kong-Hwa; Wai, Chien M

2011-01-01

Catalytic hydrogenation of polycyclic aromatic hydrocarbons (PAHs) with up to four fused benzene rings over high-density-polyethylene-stabilized palladium nanoparticles in supercritical carbon dioxide via in situ UV/Vis spectroscopy is presented. PAHs can be efficiently converted to saturated polycyclic hydrocarbons using this green technique under mild conditions at 20 MPa of CO₂ containing 1 MPa of H₂ at 40-50°C. Kinetic studies based on in situ UV/Vis spectra of the CO₂ phase reveal that the initial hydrogenation of a given PAH and the subsequent hydrogenations of its intermediates are pseudo-first-order. The hydrogenation rate of the latter is always much smaller than that of the former probably due to increasing steric hindrance introduced by the hydrogenated benzene rings of PAHs which impedes the adsorption process and hydrogen access to PAHs on catalyst surfaces. Copyright © 2010 Elsevier Ltd. All rights reserved.

Batch and Flow Photochemical Benzannulations Based on the Reaction of Ynamides and Diazo Ketones. Application to the Synthesis of Polycyclic Aromatic and Heteroaromatic Compounds

PubMed Central

Willumstad, Thomas P.; Haze, Olesya; Mak, Xiao Yin; Lam, Tin Yiu; Wang, Yu-Pu; Danheiser*, Rick L.

2013-01-01

Highly substituted polycyclic aromatic and heteroaromatic compounds are produced via a two-stage tandem benzannulation/cyclization strategy. The initial benzannulation step proceeds via a pericyclic cascade mechanism triggered by thermal or photochemical Wolff rearrangement of a diazo ketone. The photochemical process can be performed using a continuous flow reactor which facilitates carrying out reactions on a large scale and minimizes the time required for photolysis. Carbomethoxy ynamides as well as more ketenophilic bissilyl ynamines and N-sulfonyl and N-phosphoryl ynamides serve as the reaction partner in the benzannulation step. In the second stage of the strategy, RCM generates benzofused nitrogen heterocycles, and various heterocyclization processes furnish highly substituted and polycyclic indoles of types that were not available by using the previous cyclobutenone-based version of the tandem strategy. PMID:24116731

Development of multi-membrane near-infrared diode mass spectrometer for field analysis of aromatic hydrocarbons.

PubMed

Mach, Phillip M; Wright, Kenneth C; Verbeck, Guido F

2015-02-01

Membrane Inlet Mass Spectrometry (MIMS) is a technique that incorporates a semi-permeable membrane selective for differing organic molecules and chemistries. This eliminates the need for time-consuming sample preparation and facilitates near instantaneous analysis. This study will examine how the front end of MIMS incorporates three dual inlet ports, allowing for differing MIMS materials and selectivity for specific environments. Polydimethylsiloxane (PDMS) membranes have proven to be selective of benzene, toluene, and xylene (BTX) as well as aromatic hydrocarbons that are common in petroleum products while remaining selective against the aliphatic chains. PDMS has proven to be a successful choice of membrane with high permeability in atmospheric environments. In addition, polycyclic aromatic hydrocarbons (PAHs) such as acenaphthene, acenapthylene, naphthalene, and fluorene have recently been detected to the 5 ppb level in a nitrogen atmosphere with our current configuration. This preliminary work provides proof of concept using near-infrared laser diodes that act upon the membrane to increase its permeability and provide higher sensitivity of aromatic samples.

Polycyclic aromatic hydrocarbons in Cambodian smoked fish.

PubMed

Slámová, Tereza; Fraňková, Adéla; Hubáčková, Anna; Banout, Jan

2017-12-01

More than 85% of the population in Cambodia is strongly dependent on agriculture, of which freshwater aquaculture is one of the most important sources of food production. The smoked fish represents an important source of nutrients for Cambodian population; however, it can also lead to excessive intake of polycyclic aromatic hydrocarbons (PAHs). A field survey was conducted among selected smoked fish producers near to Tonle Sap river in Kampong Chhnang province, Cambodia. The study revealed that maximal limits for benzo[a]pyrene and the sum of four PAHs given by EC 1881/2006 were exceeded 2-50 times. Such burden can lead to increased risk of development of carcinogenic diseases.

A further study of air pollution in diesel bus garages.

PubMed Central

Waller, R E; Hampton, L; Lawther, P J

1985-01-01

The concentrations of smoke, polycyclic aromatic hydrocarbons (PAHs), and some gaseous air pollutants have been measured in two London Transport diesel bus garages and compared with observations made in the same garages over 20 years earlier. The main feature of the results was a large reduction in the background concentrations of smoke and polycyclic aromatic hydrocarbons from sources such as coal fires, attributable to the implementation of the Clean Air Act. Contributions from the buses to the benzo(a) pyrene content of the air inside the garages were of the same magnitude as before, being small in relation to former coal smoke contributions. PMID:4074654

Assessment of Polycyclic Aromatic Hydrocarbon Contamination of Breeding Pools Utilized by the Puerto Rican Crested Toad, Peltophryne lemur

PubMed Central

Gjeltema, Jenessa; Stoskopf, Michael; Shea, Damian; De Voe, Ryan

2012-01-01

Habitat preservation and management may play an important role in the conservation of the Puerto Rican crested toad, Peltophryne lemur, due to this species' small geographic range and declining native wild population. Bioavailable water concentrations of Polycyclic Aromatic Hydrocarbon (PAH) contaminants within breeding pools at 3 sites were established using Passive Sampling Devices (PSDs) and gas chromatography-mass spectrometry (GC/MS). A more diverse population of PAH analytes were found in higher concentrations at the breeding site that allowed direct vehicular access, but calculated risk quotients indicated low risk to toad reproduction associated with the current PAH analyte levels. PMID:23762634

Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

PubMed Central

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

2010-01-01

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. PMID:20396670

Effects of polycyclic aromatic compounds in fine particulate matter generated from household coal combustion on response to EGFR mutations in vitro.

PubMed

Ho, Kin-Fai; Chang, Chih-Cheng; Tian, Linwei; Chan, Chi-Sing; Musa Bandowe, Benjamin A; Lui, Ka-Hei; Lee, Kang-Yun; Chuang, Kai-Jen; Liu, Chien-Ying; Ning, Zhi; Chuang, Hsiao-Chi

2016-11-01

Induction of PM 2.5 -associated lung cancer in response to EGFR-tyrosine kinase inhibitors (EGFR-TKI) remains unclear. Polycyclic aromatic hydrocarbons (PAHs) and their polar derivatives (oxygenated PAHs: OPAHs and azaarenes: AZAs) were characterized in fine particulates (PM 2.5 ) emitted from indoor coal combustion. Samples were collected in Xuanwei (Yunnan Province), a region in China with a high rate of lung cancer. Human lung adenocarcinoma cells A549 (with wild-type EGFR) and HCC827 (with EGFR mutation) were exposed to the PM 2.5 , followed by treatment with EGFR-TKI. Two samples showed significant and dose-dependent reduction in the cell viability in A549. EGFR-TKI further demonstrated significantly decreased in cell viability in A549 after exposure to the coal emissions. Chrysene and triphenylene, dibenzo[a,h]anthracene, benzo[ghi]perylene, azaarenes and oxygenated polycyclic aromatic hydrocarbons (carbonyl-OPAHs) were all associated with EGFR-TKI-dependent reduced cell viability after 72-h exposure to the PM 2.5 . The findings suggest the coal emissions could influence the response of EGFR-TKI in lung cancer cells in Xuanwei. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of semipermeable membrane devices for long-term monitoring of polycyclic aromatic hydrocarbons at various stages of drinking water treatment.

PubMed

Pogorzelec, Marta; Piekarska, Katarzyna

2018-08-01

The primary goal of the presented study was the investigation of occurrence and concentration of sixteen selected polycyclic aromatic hydrocarbons in samples from various stages of water treatment and verification of the applicability of semi-permeable membrane devices in the monitoring of drinking water. Another objective was to verify if weather seasons affect the concentration and complexity of PAHs. For these purposes, semipermeable membrane devices were installed in a surface water treatment plant located in Lower Silesia (Poland). Samples were collected monthly over a period of one year. To determine the effect of water treatment on PAH concentrations, four sampling sites were selected: raw water input, a stream of water in the pipe just before ozonation, treated water output and water after passing through the distribution system. After each month of sampling, SPMDs were exchanged for fresh ones and prepared for instrumental analysis. Concentrations of polycyclic aromatic hydrocarbons were determined by high-performance liquid chromatography (HPLC). The presented study indicates that semipermeable membrane devices can be an effective tool for the analysis of drinking water, in which organic micropollutants occur at very low concentrations. Copyright © 2018 Elsevier B.V. All rights reserved.

Graphene oxide bonded fused-silica fiber for solid-phase microextraction-gas chromatography of polycyclic aromatic hydrocarbons in water.

PubMed

Xu, Lili; Feng, Juanjuan; Li, Jubai; Liu, Xia; Jiang, Shengxiang

2012-01-01

A novel chemically bonded graphene oxide/fused-silica fiber was prepared and applied in solid-phase microextraction of six polycyclic aromatic hydrocarbons from water samples coupled with gas chromatography. It exhibited high extraction efficiency and excellent stability. Effects of extraction time, extraction temperature, ionic strength, stirring rate and desorption conditions were investigated and optimized in our work. Detection limits to the six polycyclic aromatic hydrocarbons were less than 0.08 μg/L, and their calibration curves were all linear (R(2)≥0.9954) in the range from 0.05 to 200 μg/L. Single fiber repeatability and fiber-to-fiber reproducibility were less than 6.13 and 15.87%, respectively. This novel fiber was then utilized to analyze two real water samples from the Yellow River and local waterworks, and the recoveries of samples spiked at 1 and 10 μg/L ranged from 84.48 to 118.24%. Compared with other coating materials, this graphene oxide-coated fiber showed many advantages: wide linear range, low detection limit, and good stability in acid, alkali, organic solutions and at high temperature. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Consensus sediment quality guidelines for polycyclic aromatic hydrocarbon mixtures

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

Swartz, R.C.

1999-04-01

Sediment quality guidelines (SQGs) for polycyclic aromatic hydrocarbons (PAHs) have been derived from a variety of laboratory, field, and theoretical foundations. They include the screening level concentration, effects ranges-low and -median, equilibrium partitioning concentrations, apparent effects threshold, {Sigma}PAH model, and threshold and probable effects levels. The resolution of controversial differences among the PAH SQGs lies in an understanding of the effects of mixtures. Polycyclic aromatic hydrocarbons virtually always occur in field-collected sediment as a complex mixture of covarying compounds. When expressed as a mixture concentration, that is, total PAH (TPAH), the guidelines form three clusters that were intended in theirmore » original derivations to represent threshold (TEC = 290 {micro}g/g organic carbon [OC]), median (MEC = 1,800 {micro}g/g OC), and extreme (EEC = 10,000 {micro}g/g OC) effects concentrations. The TEC/MEC/EEC consensus guidelines provide a unifying synthesis of other SQGs, reflect causal rather than correlative effects, account for mixtures, and predict sediment toxicity and benthic community perturbations at sites of PAH contamination. The TEC offers the most useful SQG because PAH mixtures are unlikely to cause adverse effects on benthic ecosystems below the TEC.« less

MODELING AROMATIC AND POLYCYCLIC AROMATIC HYDROCARBON FORMATION IN PREMIXED METHANE AND ETHANE FLAMES. (R825412)

EPA Science Inventory

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

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 ...

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...

MINERALIZATION OF A SORBED POLYCYCLIC AROMATIC HYDROCARBON IN TWO SOILS USING CATALYZED HYDROGEN PEROXIDE. (R826163)

EPA Science Inventory

Hydrogen peroxide (H₂O₂) catalyzed by soluble iron or naturally occurring soil minerals, (i.e., modified Fenton's reagent) was investigated as a basis for mineralizing sorbed and NAPL-phase benzo[a]pyrene (BaP), a hydrophobic and toxic polycyclic a...

Structure, function and carcinogenicity of metabolites of methylated and non-methylated polycyclic aromatic hydrocarbons: a comprehensive review.

PubMed

Flesher, James W; Lehner, Andreas F

2016-01-01

The Unified Theory of PAH Carcinogenicity accommodates the activities of methylated and non-methylated polycyclic aromatic hydrocarbons (PAHs) and states that substitution of methyl groups on meso-methyl substituted PAHs with hydroxy, acetoxy, chloride, bromide or sulfuric acid ester groups imparts potent cancer producing properties. It incorporates specific predictions from past researchers on the mechanism of carcinogenesis by methyl-substituted hydrocarbons, including (1) requirement for metabolism to an ArCH2X type structure where X is a good leaving group and (2) biological substitution of a meso-methyl group at the most reactive center in non-methylated hydrocarbons. The Theory incorporates strong inferences of Fieser: (1) The mechanism of carcinogenesis involves a specific metabolic substitution of a hydrocarbon at its most reactive center and (2) Metabolic elimination of a carcinogen is a detoxifying process competitive with that of carcinogenesis and occurring by a different mechanism. According to this outlook, chemical or biochemical substitution of a methyl group at the reactive meso-position of non-methylated hydrocarbons is the first step in the mechanism of carcinogenesis for most, if not all, PAHs and the most potent metabolites of PAHs are to be found among the meso methyl-substituted hydrocarbons. Some PAHs and their known or potential metabolites and closely related compounds have been tested in rats for production of sarcomas at the site of subcutaneous injection and the results strongly support the specific predictions of the Unified Theory.

Mineral dust aerosols promote the formation of toxic nitropolycyclic aromatic compounds

PubMed Central

Kameda, Takayuki; Azumi, Eri; Fukushima, Aki; Tang, Ning; Matsuki, Atsushi; Kamiya, Yuta; Toriba, Akira; Hayakawa, Kazuichi

2016-01-01

Atmospheric nitrated polycyclic aromatic hydrocarbons (NPAHs), which have been shown to have adverse health effects such as carcinogenicity, are formed in part through nitration reactions of their parent polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. However, little is known about heterogeneous nitration rates of PAHs by gaseous NO2 on natural mineral substrates, such as desert dust aerosols. Herein by employing kinetic experiments using a flow reactor and surface analysis by Fourier transform infrared spectroscopy with pyridine adsorption, we demonstrate that the reaction is accelerated on acidic surfaces of mineral dust, particularly on those of clay minerals. In support of this finding, we show that levels of ambient particle-associated NPAHs in Beijing, China, significantly increased during heavy dust storms. These results suggest that mineral dust surface reactions are an unrecognized source of toxic organic chemicals in the atmosphere and that they enhance the toxicity of mineral dust aerosols in urban environments. PMID:27075250

Use of constant wavelength synchronous spectrofluorimetry for identification of polycyclic aromatic hydrocarbons in air particulate samples

NASA Astrophysics Data System (ADS)

Sharma, Homdutt; Jain, V. K.; Khan, Zahid H.

2013-05-01

We have developed a simple, rapid, inexpensive method for the identification of fluoranthene (Flan), benz(a)anthracene (BaA), benzo(a)pyrene (BaP), benzo(k)fluoranthene (BkF), pyrene (Pyr), benz(ghi)perylene (BghiP) in suspended particulate matter in an urban environment of Delhi. Suspended particulate matter samples of 24 h duration were collected on glass fiber filter papers. Polycyclic aromatic hydrocarbons (PAHs) were extracted from the filter papers using dichloromethane (DCM) and hexane with ultrasonication method. Comparison of the characteristic emission of spectra of PAHs with standard spectra indicated the degree of condensation of aromatic compounds present in investigated mixtures. It was also possible to identify some individual compounds. However, this identification could be more effective with the use of the respective values of Δλ parameter for each particular component of the mixture.

Peripherally hydrogenated neutral polycyclic aromatic hydrocarbons as carriers of the 3 micron interstellar infrared emission complex: results from single-photon infrared emission spectroscopy

NASA Technical Reports Server (NTRS)

Wagner, D. R.; Kim, H. S.; Saykally, R. J.

2000-01-01

Infrared emission spectra of five gas-phase UV laser-excited polycyclic aromatic hydrocarbons (PAHs) containing aliphatic hydrogens are compared with the main 3.3 microns and associated interstellar unidentified infrared emission bands (UIRs). We show that neutral PAHs can account for the majority of the 3 microns emission complex while making little contribution to the other UIR bands; peripherally hydrogenated PAHs produce a better match to astrophysical data than do those containing methyl side groups; 3.4 microns plateau emission is shown to be a general spectral feature of vibrationally excited PAHs containing aliphatic hydrogens, especially those containing methyl groups; and finally, hot-band and overtone emissions arising from aromatic C-H vibrations are not observed in laboratory emission spectra, and therefore, in contrast to current assignments, are not expected to be observed in the UIRs.

Natural mediators in the oxidation of polycyclic aromatic hydrocarbons by laccase mediator systems

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

Johannes, C.; Majcherczyk, A.

2000-02-01

The oxidation of polycyclic aromatic compounds was studied in systems consisting of laccase from Trametes versicolor and so-called mediator compounds. The enzymatic oxidation of acenaphthene, acenaphthylene, anthracene, and fluorene was mediated by various laccase substrates (phenols and aromatic amines) or compounds produced and secreted by white rot fungi. The best natural mediators, such as phenol, aniline, 4-hydroxybenzoic acid, and 4-hydroxybenzyl alcohol were as efficient as the previously described synthetic compounds ABTS [2,2{prime}-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)] and 1-hydroxybenzotriazole. The oxidation efficiency increased proportionally with the redox potentials of the phenolic mediators up to a maximum value of 0.9 V and decreased thereafter withmore » redox potentials exceeding this value. Natural compounds such as methionine, cysteine, and reduced glutathione, containing sulfhydryl groups, were also active as mediator compounds.« less

Embryotoxic and teratogenic effects of petroleum hydrocarbons in mallards (Anas platyrhynchos)

USGS Publications Warehouse

Hoffman, D.J.

1979-01-01

Egg surface applications of microliter quantities of crude and refined oils of high aromatic content are embryotoxic to mallards (Anas platyrhynchos) and other avian species; applications of aliphatic hydrocarbons have virtually no effect. Mallard eggs at 72 h of development were exposed to a mixture of aromatic hydrocarbons or to aromatic compounds representative to those present in crude oil to assess their toxicity. The class composition of the mixture was similar to that of South Louisiana crude oil, an American Petroleum Institute reference oil. Application of 20 microliter of the mixture reduced embryonic survival by nearly 70%. The temporal pattern of embryonic death was similar to that after exposure to South Louisiana crude oil. Embryonic growth was stunted, as reflected by weight, crown-rump length, and bill length, and there was a significant increase in the incidence of abnormal survivors. When individual classes of aromatic hydrocarbons were tested, tetracyclics caused some embryonic death at the concentrations in the mixture. When classes were tested in all possible combinations of two, no combination appeared to be as toxic as the entire mixture. Addition of the tetracyclic compound chrysene to the aromatic mixture considerably enhanced embryotoxicity, but could not completely account for the toxicity of the crude oil. The presence of additional unidentified polycyclic aromatic hydrocarbons as well as methylated derivatives of polycyclic aromatic compounds such as chrysene may further account for the embryotoxicity of the crude oil.

Fluorescent aromatic sensors and their methods of use

NASA Technical Reports Server (NTRS)

Meador, Michael A. (Inventor); Tyson, Daniel S. (Inventor); Ilan, Ulvi F. (Inventor)

2012-01-01

Aromatic molecules that can be used as sensors are described. The aromatic sensors include a polycyclic aromatic hydrocarbon core with a five-membered imide rings fused to the core and at least two pendant aryl groups. The aromatic sensor molecules can detect target analytes or molecular strain as a result of changes in their fluorescence, in many cases with on-off behavior. Aromatic molecules that fluoresce at various frequencies can be prepared by altering the structure of the aromatic core or the substituents attached to it. The aromatic molecules can be used as sensors for various applications such as, for example, the detection of dangerous chemicals, biomedical diagnosis, and the detection of damage or strain in composite materials. Methods of preparing aromatic sensor molecules are also described.

Heavy metal-immobilizing organoclay facilitates polycyclic aromatic hydrocarbon biodegradation in mixed-contaminated soil.

PubMed

Biswas, Bhabananda; Sarkar, Binoy; Mandal, Asit; Naidu, Ravi

2015-11-15

Soils contaminated with a mixture of heavy metals and polycyclic aromatic hydrocarbons (PAHs) pose toxic metal stress to native PAH-degrading microorganisms. Adsorbents such as clay and modified clay minerals can bind the metal and reduce its toxicity to microorganisms. However, in a mixed-contaminated soil, an adsorption process more specific to the metals without affecting the bioavailability of PAHs is desired for effective degradation. Furthermore, the adsorbent should enhance the viability of PAH-degrading microorganisms. A metal-immobilizing organoclay (Arquad(®) 2HT-75-bentonite treated with palmitic acid) (MIOC) able to reduce metal (cadmium (Cd)) toxicity and enhance PAH (phenanthrene) biodegradation was developed and characterized in this study. The MIOC differed considerably from the parent clay in terms of its ability to reduce metal toxicity (MIOC>unmodified bentonite>Arquad-bentonite). The MIOC variably increased the microbial count (10-43%) as well as activities (respiration 3-44%; enzymatic activities up to 68%), and simultaneously maintained phenanthrene in bioavailable form in a Cd-phenanthrene mixed-contaminated soil over a 21-day incubation period. This study may lead to a new MIOC-assisted bioremediation technique for PAHs in mixed-contaminated soils. Copyright © 2015 Elsevier B.V. All rights reserved.

Molecular Spectroscopy in Astrophysics: The Case of Polycyclic Aromatic Hydrocarbons

NASA Technical Reports Server (NTRS)

Salama, Farid; DeVincent, Donald L. (Technical Monitor)

2000-01-01

The role of molecular spectroscopy in astrophysics and astrochemistry is discussed in the context of the study of large, complex, carbon-bearing molecules, namely, Polycyclic Aromatic Hydrocarbons or PAHs. These molecular species are now thought to be widespread in the interstellar medium in their neutral and ionized forms. Identifying the carriers responsible for unidentified interstellar spectral bands will allow to derive important information on cosmic elemental abundances as well as information on the physical conditions (density, temperature) reigning in specific interstellar environments. These, in turn, are key elements for a correct understanding of the energetic mechanisms that govern the origin and the evolution of the interstellar medium. A multidisciplinary approach - combining astronomical observations with laboratory simulations and theoretical modeling - is required to address these complex issues. Laboratory spectra of several PAHs, isolated at low temperature in inert gas matrices or seeded in a supersonic jet expansion, are discussed here and compared to the astronomical spectra of reddened, early type, stars. The electronic spectroscopy of PAHs in the ultraviolet, visible, and near-infrared domains is reviewed and an assessment of the potential contribution of PAHs to the interstellar extinction in the ultraviolet and in the visible is discussed.

Diversity of metabolic capacities among strains degrading polycyclic aromatic hydrocarbons

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

Bouchez, M.; Besnaienou, B.; Blanchet, D.

1995-12-31

Strains of Pseudomonas and Rhodococcus genera were isolated for their capacity to use, as a sole carbon and energy source, one of the following polycyclic aromatic hydrocarbons (PAHs): naphthalene (NAP), fluorene (FLU), phenanthrene (PHE), anthracene (ANT), fluoranthene (FLT), and pyrene (PYR). The range of PAHs supporting growth of these pure strains was usually restricted, but several other hydrocarbons were used by Rhodococcus sp. All strains could grow on simple organic acids. Maximal specific growth rates ({mu}{sub max}) of all strains on their PAH growth substrates were determined by respirometry. No clear relationships between {mu}{sub max} values and the molecular weightmore » or water solubility of PAHs were apparent, but Pseudomonas sp. exhibited the highest {mu}{sub max} values. Carbon balances for PAH biodegradation were established. Differences between strains were observed, but high mineralization rates and low production of soluble metabolites were obtained for all PAHs. Bacterial biomass represented 16% to 35% of the carbon consumed. Strain diversity was also apparent in the interactions observed in the degradation of a mixture of two PAHs by individual strains, which often involved inhibition of PAH substrate degradation, with or without cometabolization of the second PAH.« less

Polycyclic aromatic hydrocarbons and cytochrome P450 in HIV pathogenesis

PubMed Central

Rao, P. S. S.; Kumar, Santosh

2015-01-01

High prevalence of cigarette smoking in HIV patients is associated with increased HIV pathogenesis and disease progression. While the effect of smoking on the occurrence of lung cancer has been studied extensively, the association between smoking and HIV pathogenesis is poorly studied. We have recently shown the possible role of cytochrome P450 (CYP) in smoking/nicotine-mediated viral replication. In this review, we focus on the potential role of CYP pathway in polycyclic aromatic hydrocarbons (PAH), important constituents of cigarette smoke, mediated HIV pathogenesis. More specifically, we will discuss the role of CYP1A1 and CYP1B1, which are the major PAH-activating CYP enzymes. Our results have shown that treatment with cigarette smoke condensate (CSC) increases viral replication in HIV-infected macrophages. CSC contains PAH, which are known to be activated by CYP1A1 and CYP1B1 into procarcinogens/toxic metabolites. The expression of these CYPs is regulated by aryl hydrocarbon receptors (AHR), the cellular target of PAH, and an important player in various diseases including cancer. We propose that PAH/AHR-mediated CYP pathway is a novel target to develop new interventions for HIV positive smokers. PMID:26082767

Spatial-temporal trend and health implications of polycyclic aromatic hydrocarbons (PAHs) in resident oysters, South China Sea: A case study of Eastern Guangdong coast.

PubMed

Yu, Zi-Ling; Lin, Qin; Gu, Yang-Guang; Ke, Chang-Liang; Sun, Run-Xia

2016-09-15

Spatial and temporal distributions of polycyclic aromatic hydrocarbons (PAHs) were investigated in Eastern Guangdong coast, China. Total PAH concentrations in oysters ranged from 231 to 1178ng/g with a mean concentration of 622ng/g dry weight. Compared with other bays and estuaries, PAH levels in oysters were moderate. Spatial distribution of PAHs was site specific, with relatively high PAH concentrations observed in Zhelin Bay and Kaozhouyang Bay. Based on the Spearman test analysis, only PAH concentration in oysters from Jiazi Harbor showed a significant increasing trend (P<0.05). Three-ring PAHs were the most abundant, accounting for 54.2%-88.4% of total PAHs. Diagnostic ratios suggested that PAHs were derived mainly from petroleum origin. BaP and ∑4PAH concentrations were well within the European Union limits (5ng/g and 30ng/g wet weight, respectively). The incremental lifetime cancer risks (ILCR) for PAHs were <10(-5), indicating that the adverse health risks associated with oyster consumption in this area were minimal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ion-polycyclic aromatic hydrocarbon collisions: kinetic energy releases for specific fragmentation channels

NASA Astrophysics Data System (ADS)

Reitsma, G.; Zettergren, H.; Boschman, L.; Bodewits, E.; Hoekstra, R.; Schlathölter, T.

2013-12-01

We report on 30 keV He2 + collisions with naphthalene (C10H8) molecules, which leads to very extensive fragmentation. To unravel such complex fragmentation patterns, we designed and constructed an experimental setup, which allows for the determination of the full momentum vector by measuring charged collision products in coincidence in a recoil ion momentum spectrometer type of detection scheme. The determination of fragment kinetic energies is found to be considerably more accurate than for the case of mere coincidence time-of-flight spectrometers. In fission reactions involving two cationic fragments, typically kinetic energy releases of 2-3 eV are observed. The results are interpreted by means of density functional theory calculations of the reverse barriers. It is concluded that naphthalene fragmentation by collisions with keV ions clearly is much more violent than the corresponding photofragmentation with energetic photons. The ion-induced naphthalene fragmentation provides a feedstock of various small hydrocarbonic species of different charge states and kinetic energy, which could influence several molecule formation processes in the cold interstellar medium and facilitates growth of small hydrocarbon species on pre-existing polycyclic aromatic hydrocarbons.

Concentrations of polybrominated diphenyl ethers, hexachlorobenzene and polycyclic aromatic hydrocarbons in various foodstuffs before and after cooking.

PubMed

Perelló, Gemma; Martí-Cid, Roser; Castell, Victoria; Llobet, Juan M; Domingo, José L

2009-04-01

The cooking-induced changes in the levels of polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), and 16 polycyclic aromatic hydrocarbons (PAHs) in various foodstuffs were investigated. Foods included fish (sardine, hake and tuna), meat (veal steak, loin of pork, breast and thigh of chicken, and steak and rib of lamb), string bean, potato, rice, and olive oil. For each food item, raw and cooked (fried, grilled, roasted, boiled) samples were analyzed. There were some variations in the concentrations of PBDEs before and after cooking. However, they depended not only on the cooking process, but mainly on the specific food item. The highest HCB concentrations were found in sardine, being lower in cooked samples. All cooking processes enhanced HCB levels in hake, while very scarce differences could be noted in tuna (raw and cooked). In general terms, the highest PAH concentrations were found after frying by being the values especially notable in fish, excepting hake, where the highest total PAH levels corresponded to roasted samples. The results of this study show that, in general, cooking processes are only of a limited value as a means of reducing PBDE, HCB and PAH concentrations in food.

Degradation of polycyclic aromatic hydrocarbons (PAHs) by a mixed culture and its component pure cultures, obtained from PAH-contaminated soil.

PubMed

Trzesicka-Mlynarz, D; Ward, O P

1995-06-01

A mixed culture, isolated from soil contaminated with polycyclic aromatic hydrocarbons (PAHs), grew on and degraded fluoranthene in aqueous media supplemented with glucose, yeast extract, and peptone. Increased complex nitrogen levels in the medium promoted bacterial growth and a greater extent of fluoranthene degradation. Amendment of the media with high glucose levels also diminished specific fluoranthene degradation. The mixed culture was capable of degrading a range of other PAHs, including benzo[a]pyrene, anthracene, phenanthrene, acenaphthene, and fluorene. The mixed culture contained four predominant isolates, all of which were Gram-negative rods, three of which were identified as Pseudomonas putida, Flavobacterium sp., and Pseudomonas aeruginosa. Better degradation of a defined PAH mixture was observed with the mixed culture than with individual isolates. A reconstituted culture, prepared by combining the four individual isolates, manifested a similar PAH biodegradation performance to the original mixed culture. When compared with the mixed culture, individual isolates exhibited a relatively good capacity to remove more water-soluble PAHs (acenaphthene, fluorene, phenanthrene, fluoranthene). In contrast, removal of less water-soluble PAHs (anthracene and pyrene) was low or negligible with isolated cultures compared with the mixed culture.

Spatial Characterization of Polycyclic Aromatic Hydrocarbons in 2008 TC3 Samples

NASA Astrophysics Data System (ADS)

Sabbah, Hassan; Morrow, A.; Zare, R. N.; Jenniskens, P.

2009-09-01

Hassan Sabbah1, Amy L. Morrow1, Richard N. Zare1 and Petrus Jenniskens2 1Stanford University, Stanford, California 94305, 2 SETI Institute, Carl Sagan Center, 515 North Whisman Road, Mountain View, California 94043, USA. In October 2006 a small asteroid (2-3 meters) was observed in outer space. On October 7, 2008, it entered the Earth's atmosphere creating a fireball over Northern Sudan. Some 280 meteorites were collected by the University of Khartoum. In order to explore the existence of organic materials, specifically polycyclic aromatic hydrocarbons (PAHs), we applied two-step laser desorption laser ionization mass spectrometry (L2MS) to some selected fragments. This technique consists of desorbing with a pulsed infrared laser beam the solid materials into a gaseous phase with no fragmentation followed by resonance enhanced multiphoton ionization to analyze the PAH content. L2MS was already applied to an array of extraterrestrial objects including interplanetary dust particles IDPs, carbonaceous chondrites and comet coma particles. Moreover, spatial resolution of PAHs in 2008 TC3 samples was achieved to explore the heterogeneity within individual fragments. The results of these studies and their contribution to understanding the formation of this asteroid will be discussed.

Photodegradation of selected polycyclic aromatic hydrocarbons in surface microlayer under direct solar irradiance

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

Liu, K.; Dickhut, R.M.

1995-12-31

Photodegradation kinetics of selected polycyclic aromatic hydrocarbons (PAHs) in the presence of various particle and dissolved phases were examined in surface microlayer (SM) and surface water under direct solar irradiance during different seasons. Halflives of PAHs during different seasons in the various media were determined. The results showed shorter halflives measured at the surface for PAHs in the SM media than in surface water. Submergence depth also significantly affected rate constants, and halflives for PAH compounds were 1.4 to 5 times shorter at the surface than at 14cm depth below the surface. In bulk SM media, the annual average halflivesmore » varied from 1.3 to 43 hours (midday) with different PAH compounds, and in filtered SM from 1.8 to 56.9 hours (midday). The effects of particles and DOC on the photodegradation of PAHs were also inspected. The results showed particulates and DOC both enhanced or decreased the photodegradation rate constants for selected PAHs. Overall, PAH photoreactivity is related to the compound`s maximum net atomic charge (MNAC) on the most reactive carbon center of a specific PAH molecule.« less

Characterization of a Microbial Consortium for the Bioremoval of Polycyclic Aromatic Hydrocarbons (PAHs) in Water

PubMed Central

Blanco-Enríquez, Esmeralda G.; Zavala-Díaz de la Serna, Francisco Javier; Peralta-Pérez, María del Rosario; Ballinas-Casarrubias, Lourdes; Salmerón, Iván; Rubio-Arias, Héctor; Rocha-Gutiérrez, Beatriz A.

2018-01-01

Pollution of freshwater ecosystems from polycyclic aromatic hydrocarbons (PAHs) is a global concern. The US Environmental Protection Agency (EPA) has included the PAHs pyrene, phenanthrene, and naphthalene among the 16 priority compounds of special concern for their toxicological effects. The aim of this study was to adapt and characterize a microbial consortium from ore waste with the potential to remove these three PAHs from water. This microbial consortium was exposed to the target PAHs at levels of 5, 10, 20, 50, and 100 mg L−1 for 14 days. PAH bioremoval was measured using the analytical technique of solid phase microextraction, followed by gas chromatography mass spectrometry (SPME-GC/MS). The results revealed that up to 90% of the target PAHs can be removed from water after 14 days at a concentration level of 100 mg L−1. The predominant group of microorganisms identified at the phylum taxonomic level were the Proteobacteria, while the Actinobacteria were the predominant subgroup. The removal of phenanthrene, naphthalene, and pyrene predominantly occurred in specimens of genera Stenotrophomonas, Williamsia, and Chitinophagaceae, respectively. This study demonstrates that the use of specific microorganisms is an alternative method of reducing PAH levels in water. PMID:29757264

Reflectance spectroscopy (350-2500 nm) of solid-state polycyclic aromatic hydrocarbons (PAHs)

NASA Astrophysics Data System (ADS)

Izawa, M. R. M.; Applin, D. M.; Norman, L.; Cloutis, E. A.

2014-07-01

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds based on fused aromatic rings, and are formed in a variety of astrophysical, solar nebula and planetary processes. Polycyclic aromatic hydrocarbons are known or suspected to occur in a wide variety of planetary settings including icy satellites, Titan’s hazes, carbonaceous meteorites, comet nuclei, ring particles; and terrestrial organic-rich lithologies such as coals, asphaltites, and bituminous sands. Relatively few measurements of the visible and near-infrared spectra of PAHs exist, yet this wavelength region (350-2500 nm) is widely used for remote sensing. This study presents detailed analyses of the 350-2500 nm reflectance spectra of 47 fine-grained powders of different high-purity solid-state PAHs. Spectral properties of PAHs change with variations in the number and connectivity of linked aromatic rings and the presence and type of side-groups and heterocycles. PAH spectra are characterized by three strong features near ∼880 nm, ∼1145 nm, and ∼1687 nm due to overtones of νCH fundamental stretching vibrations. Some PAHs are amenable to remote detection due to the presence of diagnostic spectral features, including: Nsbnd H stretching overtones at 1490-1515 nm in NH- and NH2-bearing PAHs, aliphatic or saturated bond Csbnd H overtone vibrations at ∼1180-1280 nm and ∼1700-1860 nm; a broad asymmetric feature between ∼1450 nm and ∼1900 nm due to Osbnd H stretching overtones in aromatic alcohols, Csbnd H and Cdbnd O combinations near ∼2000-2010 nm and ∼2060-2270 nm in acetyl and carboxyl-bearing PAHs. Other substituents such as sulphonyl, thioether ether and carboxyl heterocycles, or cyano, nitrate, and aromatic side groups, do not produce well-resolved diagnostic spectral features but do cause shifts in the positions of the aromatic Csbnd H vibrational overtone features. Fluorescence is commonly suppressed by the presence of heterocycles, side-groups and in many non-alternant PAHs. The spectral characteristics of PAHs offer the potential, under suitable circumstances, for remote characterization of the classes of PAH present and in some cases, identification of particular heterocyclic or side-group substituents.

Off-site impacts of wildfires on aquatic systems - Biomarker responses of the mosquitofish Gambusia holbrooki.

PubMed

Nunes, Bruno; Silva, Vera; Campos, Isabel; Pereira, Joana Luísa; Pereira, Patrícia; Keizer, Jan Jacob; Gonçalves, Fernando; Abrantes, Nelson

2017-03-01

The number of wildfires has markedly increased in Mediterranean Europe, including in Portugal. Wildfires are environmentally concerning, not only due to the loss of biodiversity and forest area, but also as a consequence of environmental contamination by specific compounds including metals and polycyclic aromatic compounds (PAHs). These contaminants, mostly bound to ashes, can reach downstream water bodies, namely through surface runoff, being ultimately dispersed by vast areas and contacting with aquatic biota. Being toxicologically noteworthy, the potential toxic outcomes of the input of such chemicals across the aquatic compartment must be characterized. In this context, the present study used a biomarker-based approach to find early-warning signals of toxicity triggered by the exposure of the mosquitofish, Gambusia holbrooki, to affected aqueous runoff and stream water samples collected from a forest burnt area. The chemical analysis revealed concerning levels of metals and polycyclic aromatic hydrocarbons in both runoff and stream water samples. Biological responses elicited by the collected samples showed the occurrence of pro-oxidative modifications, specifically driven by enzymatic forms involved in the metabolism of glutathione. Despite these effects, no further signs of involvement of metals and PAHs were elicited in terms of neurotoxicity. The overall set of data implicates chemicals resulting from wildfires in clear deleterious effects in exposed fish. Copyright © 2017 Elsevier B.V. All rights reserved.

Source apportionment of chlorinated polycyclic aromatic hydrocarbons associated with ambient particles in a Japanese megacity

PubMed Central

Kamiya, Yuta; Iijima, Akihiro; Ikemori, Fumikazu; Okuda, Tomoaki; Ohura, Takeshi

2016-01-01

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are novel species of environmental contaminants whose possible sources remain unclear. The occurrence of ClPAHs within total suspended particles (TSP) is compared with weekly air samples at two sites of differing characteristics (industrial and residential) in the megacity of Nagoya, Japan. Samples were collected over 12 months during 2011–2012. All 24 species of targeted ClPAHs were detected at both industrial and residential sites, where mean concentrations of total ClPAHs in TSP were 20.7 and 14.1 pg/m3, respectively. High concentrations at the industrial site were frequently observed during winter, suggesting potent seasonal ClPAH sources there. Positive matrix factorization modeling of particulate ClPAH source identification and apportioning were conducted for datasets including ClPAHs, PAHs, elements and ions, plus elemental carbons in TSP. Eight factors were identified as possible ClPAH sources, with estimates that the dominant one was a specific source of ClPAH emission (31%), followed by traffic (23%), photodegradable and semi-volatile species (18%), long-range transport (11%), and industry and oil combustion (10%). Source contributions of ClPAHs differed substantially from those of PAHs. This suggests specific and/or potent ClPAH sources in the local area, and that the production mechanisms between ClPAHs and PAHs are substantially different. PMID:27922081

Polycyclic aromatic hydrocarbons, tobacco smoke, and epigenetic remodeling in asthma

PubMed Central

Klingbeil, E. C.; Hew, K. M.; Nygaard, U. C.; Nadeau, K. C.

2014-01-01

Environmental determinants including aerosolized pollutants such as polycyclic aromatic hydrocarbons (PAHs) and tobacco smoke have been associated with exacerbation and increased incidence of asthma. The influence of aerosolized pollutants on the development of immune dysfunction in asthmatics has been suggested to be mediated through epigenetic remodeling. Genome accessibility and transcription are regulated primarily through DNA methylation, histone modification, and microRNA transcript silencing. Epigenetic remodeling has been shown in studies to be associated with Th2 polarization and associated cytokine and chemokine regulation in the development of asthma. This review will present evidence for the contribution of the aerosolized pollutants PAH and environmental tobacco smoke to epigenetic remodeling in asthma. PMID:24760221

Failure of hydrogenation in protecting polycyclic aromatic hydrocarbons from fragmentation

NASA Astrophysics Data System (ADS)

Gatchell, M.; Stockett, M. H.; de Ruette, N.; Chen, T.; Giacomozzi, L.; Nascimento, R. F.; Wolf, M.; Anderson, E. K.; Delaunay, R.; Vizcaino, V.; Rousseau, P.; Adoui, L.; Huber, B. A.; Schmidt, H. T.; Zettergren, H.; Cederquist, H.

2015-11-01

A recent study of soft x-ray absorption in native and hydrogenated coronene cations, C24H12+m +m =0 -7 , led to the conclusion that additional hydrogen atoms protect (interstellar) polycyclic aromatic hydrocarbon (PAH) molecules from fragmentation [Reitsma et al., Phys. Rev. Lett. 113, 053002 (2014), 10.1103/PhysRevLett.113.053002]. The present experiment with collisions between fast (30-200 eV) He atoms and pyrene (C16H10+m + , m =0 , 6, and 16) and simulations without reference to the excitation method suggests the opposite. We find that the absolute carbon-backbone fragmentation cross section does not decrease but increases with the degree of hydrogenation for pyrene molecules.

Aromatic ring generation as a dust precursor in acetylene discharges

NASA Astrophysics Data System (ADS)

De Bleecker, Kathleen; Bogaerts, Annemie; Goedheer, Wim

2006-04-01

Production of aromatic hydrocarbon compounds as an intermediate step for particle formation in low-pressure acetylene discharges is investigated via a kinetic approach. The detailed chemical reaction mechanism contains 140 reactions among 55 species. The cyclic hydrocarbon chemistry is mainly based on studies of polycyclic aromatic hydrocarbon formation in cosmic environments. The model explicitly includes organic chain, cyclic molecules, radicals, and ions up to a size of 12 carbon atoms. The calculated density profiles show that the aromatic formation yields are quite significant, suggesting that aromatic compounds play a role in the underlying mechanisms of particle formation in hydrocarbon plasmas.

Comment on: Negative ions, molecular electron affinity and orbital structure of cata-condensed polycyclic aromatic hydrocarbons by Rustem V. Khatymov, Mars V. Muftakhov and Pavel V. Shchukin.

PubMed

Chen, Edward S; Chen, Edward C M

2018-02-15

The anion mass spectral lifetimes for several aromatic hydrocarbons reported in the subject article were related to significantly different electron affinities. The different values are rationalized using negative ion mass spectral data. Electron affinities for polycyclic aromatic hydrocarbons are reported from the temperature dependence of unpublished electron capture detector data. These are compared with published values and the largest values are assigned to the ground state. The ground state adiabatic electron affinities: (eV) pentacene, 1.41 (3); tetracene, 1.058 (5); benz(a)pyrene, 0.82 (4); benz(a) anthracene, 0.69 (2) anthracene, 0.68 (2); and pyrene, 0.59 (1) are used to assign excited state adiabatic electron affinities: (eV) tetracene: 0.88 (4); anthracene 0.53 (1); pyrene, 0.41 (1); benz(a)anthracene, 0.39 (10); chrysene, 0.32 (1); and phenanthrene, 0.12 (2) and ground state adiabatic electron affinities: (eV) dibenz(a,j)anthracene, 0.69 (3); dibenz(a,h)anthracene, 0.68 (3); benz(e)pyrene, 0.60 (3); and picene, 0.59 (3) from experimental data. The lifetime of benz(a)pyrene is predicted to be larger than 150 μs and for benzo(c)phenanthrene and picene about 40 μs, from ground state adiabatic electron affinities. The assignments of adiabatic electron affinities of aromatic hydrocarbons determined from electron capture detector and mass spectrometric data to ground and excited states are supported by constant electronegativities. A set of consistent ground state adiabatic electron affinities for 15 polycyclic aromatic hydrocarbons is related to lifetimes from the subject article. Copyright © 2017 John Wiley & Sons, Ltd.

Storm Water Toxicity Evaluation Conducted at Naval Station San Diego, Naval Submarine Base San Diego, Naval Amphibious Base Coronado, and Naval Air Station North Island

DTIC Science & Technology

2006-05-01

Polycyclic Aromatic Hydrocarbons and Petroleum to Marine Invertebrate Larvae and Juveniles,” Environ. Toxicol. Chem., vol. 16, pp. 2190–2199...aromatic hydrocarbons , polychlorinated biphenyls, and chlorinated pesticides. Seventeen plume mapping surveys, including an on-site floating bioassay...Non-point Source NS&T National Status and Trends PAH Polynuclear Aromatic Hydrocarbon PCB Polychlorinated Biphenyl PMSD Percent

Mutagenicity of an aged gasworks soil during bioslurry treatment

PubMed Central

Lemieux, Christine L; Lynes, Krista D; White, Paul A; Lundstedt, Staffan; Öberg, Lars; Lambert, Iain B

2009-01-01

This study investigated changes in the mutagenic activity of organic fractions from soil contaminated with polycyclic aromatic hydrocarbons (PAHs) during pilot-scale bioslurry remediation. Slurry samples were previously analyzed for changes in PAH and polycyclic aromatic compound content, and this study examined the correspondence between the chemical and toxicological metrics. Nonpolar neutral and semipolar aromatic fractions of samples obtained on days 0, 3, 7, 24, and 29 of treatment were assayed for mutagenicity using the Salmonella mutation assay. Most samples elicited a significant positive response on Salmonella strains TA98, YG1041, and YG1042 with and without S9 metabolic activation; however, TA100 failed to detect mutagenicity in any sample. Changes in the mutagenic activity of the fractions across treatment time and metabolic activation conditions suggests a pattern of formation and transformation of mutagenic compounds that may include a wide range of PAH derivatives such as aromatic amines, oxygenated PAHs, and S-heterocyclic compounds. The prior chemical analyses documented the formation of oxygenated PAHs during the treatment (e.g., 4-oxapyrene-5-one), and the mutagenicity analyses showed high corresponding activity in the semipolar fraction with and without metabolic activation. However, it could not be verified that these specific compounds were the underlying cause of the observed changes in mutagenic activity. The results highlight the need for concurrent chemical and toxicological profiling of contaminated sites undergoing remediation to ensure elimination of priority contaminants as well as a reduction in toxicological hazard. Moreover, the results imply that remediation efficacy and utility be evaluated using both chemical and toxicological metrics. Environ. Mol. Mutagen. 2009. © 2009 Wiley-Liss, Inc. PMID:19274766

Attributing risk burden of PM2.5-bound polycyclic aromatic hydrocarbons to major emission sources: Case study in Guangzhou, south China

NASA Astrophysics Data System (ADS)

Yu, Qingqing; Gao, Bo; Li, Guanghui; Zhang, Yanli; He, Quanfu; Deng, Wei; Huang, Zhonghui; Ding, Xiang; Hu, Qihou; Huang, Zuzhao; Wang, Yujun; Bi, Xinhui; Wang, Xinming

2016-10-01

Polycyclic aromatic hydrocarbons (PAHs) have attracted an increasing concern in China's megacities. However, rare information is available on the spatial and seasonal variations of inhalation cancer risk (ICR) due to PAH exposure and their relations to specific sources. In this study, year-round PM2.5 samples were collected from 2013 to 2014 by high-volume samplers at four sites (one urban, two rural and one roadside station) in Guangzhou in the highly industrialized and densely populated Pearl River Delta (PRD) region and analyzed for 26 polycyclic aromatic hydrocarbons (PAHs) together with molecular tracers including levoglucosan, hopanes and elemental carbon. Higher molecular weight PAHs (5-ring or above) accounted for 64.3-87.5% of total PAHs. Estimated annual averages of benzo(a)pyrene-equivalent carcinogenic potency (BaPeq) were 1.37, 2.31 and 1.56 ng/m3 at urban SZ, rural JL and rural WQS, respectively, much higher than that at the roadside station YJ in an urban street canyon. ICR of PAHs in wintertime reached 2.2 × 10-4, nearly 3 times that in summer; and cancer risk of PAHs was surprisingly higher at the rural site than at other sites. Source contributions by positive matrix factorization (PMF) in the aid of molecular tracers revealed that overall coal combustion and biomass burning altogether contributed 73.8% of total PAHs and 85.2% of BaPeq, and particularly in winter biomass burning became the most significant source of total PAHs and BaPeq (51.8% and 52.5%), followed by coal combustion (32.0% and 39.1%) and vehicle emission (16.2% and 8.4%). The findings of this work suggest that even in China's megacities like Guangzhou, limiting biomass burning may benefit PAHs pollution control and cancer risk reduction.

Atmospheric chlorinated polycyclic aromatic hydrocarbons in East Asia.

PubMed

Kakimoto, Kensaku; Nagayoshi, Haruna; Konishi, Yoshimasa; Kajimura, Keiji; Ohura, Takeshi; Hayakawa, Kazuichi; Toriba, Akira

2014-09-01

This study estimates atmospheric concentrations of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) and polycyclic aromatic hydrocarbons (PAHs) in East Asia using a Gas Chromatograph with High Resolution Mass Spectrometer (GC-HRMS). ClPAHs are ubiquitously generated from PAHs through substitution, and some ClPAHs show higher aryl hydrocarbon receptor (AhR)-mediated activities than their parent PAHs. Atmospheric particles were collected using a high-volume air sampler equipped with a quartz-fiber filter. We determined the ClPAH concentrations of atmospheric particles collected in Japan (Sapporo, Sagamihara, Kanazawa, and Kitakyushu), Korea (Busan), and China (Beijing). The concentrations of ClPAHs were highest in the winter Beijing sample, where the total mean concentration was approximately 15-70 times higher than in the winter samples from Japan and Korea. The concentrations of Σ19ClPAHs and Σ9PAHs were significantly correlated in the Kanazawa and the Busan samples. This indicates that within those cities ClPAHs and PAHs share the same origin, implying direct chlorination of parent PAHs. Toxic equivalent concentrations (TEQs) of the total ClPAHs and PAHs were lowest in Kanazawa in the summer, reaching 1.18 and 2610fg-TEQm(-3) respectively, and highest in Beijing in the winter, reaching 627 and 4240000fg-TEQm(-3) respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analytical evaluation of BEA zeolite for the pre-concentration of polycyclic aromatic hydrocarbons and their subsequent chromatographic analysis in water samples.

PubMed

Wilson, Walter B; Costa, Andréia A; Wang, Huiyong; Dias, José A; Dias, Sílvia C L; Campiglia, Andres D

2012-07-06

The analytical performance of BEA - a commercial zeolite - is evaluated for the pre-concentration of fifteen Environmental Protection Agency - polycyclic aromatic hydrocarbons and their subsequent HPLC analysis in tap and lake water samples. The pre-concentration factors obtained with BEA have led to a method with excellent analytical figures of merit. One milliliter aliquots were sufficient to obtain excellent precision of measurements at the parts-per-trillion concentration level with relative standard deviations varying from 4.1% (dibenzo[a,h]anthracene) to 13.4% (pyrene). The limits of detection were excellent as well and varied between 1.1 (anthracene) and 49.9 ng L(-1) (indeno[1,2,3-cd]pyrene). The recovery values of all the studied compounds meet the criterion for regulated polycyclic aromatic hydrocarbons, which mandates relative standard deviations equal or lower than 25%. The small volume of organic solvents (100 μL per sample) and amount of BEA (2 mg per sample) makes sample pre-concentration environmentally friendly and cost effective. The extraction procedure is well suited for numerous samples as the small working volume (1 mL) facilitates the implementation of simultaneous sample extraction. These are attractive features when routine monitoring of numerous samples is contemplated. Copyright © 2012 Elsevier B.V. All rights reserved.

Rapid determination of polycyclic aromatic hydrocarbons in rainwater by liquid-liquid microextraction and LC with core-shell particles column and fluorescence detection.

PubMed

Vinci, Giuliana; Antonelli, Marta L; Preti, Raffaella

2013-02-01

Liquid-liquid microextraction coupled to LC with fluorescence detection for the determination of Environmental Protection Agency's 16 priority pollutant polycyclic aromatic hydrocarbons in rainwater has been developed. The optimization of the extraction method has involved several parameters, including the comparison between an ultrasonic bath and a magnetic stirrer as extractant apparatus, the choice of the extractant solvent, and the optimization of the extraction time. Liquid-liquid microextraction gave good results in terms of recoveries (from 73.6 to 102.8% in rainwater) and repeatability, with a very simple procedure and low solvent consumption. The reported chromatographic method uses a Core-Shell technology column, with particle size <3 μm instead of classical 5-μm particles column. The resulting backpressure was below 300 bar, allowing the use of a conventional HPLC system rather than the more expensive ultrahigh performance LC (UHPLC). An average decrease of 59% in run time and 75% in eluent consumption has been obtained, compared to classical HPLC methods, keeping good separation, sensitivity, and repeatability. The proposed conditions were successfully applied to the determinations of polycyclic aromatic hydrocarbons in genuine rainwater samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Suspended particulate matter collection methods influence the quantification of polycyclic aromatic compounds in the river system.

PubMed

Abuhelou, Fayez; Mansuy-Huault, Laurence; Lorgeoux, Catherine; Catteloin, Delphine; Collin, Valéry; Bauer, Allan; Kanbar, Hussein Jaafar; Gley, Renaud; Manceau, Luc; Thomas, Fabien; Montargès-Pelletier, Emmanuelle

2017-10-01

In this study, we compared the influence of two different collection methods, filtration (FT) and continuous flow field centrifugation (CFC), on the concentration and the distribution of polycyclic aromatic compounds (PACs) in suspended particulate matter (SPM) occurring in river waters. SPM samples were collected simultaneously with FT and CFC from a river during six sampling campaigns over 2 years, covering different hydrological contexts. SPM samples were analyzed to determine the concentration of PACs including 16 polycyclic aromatic hydrocarbons (PAHs), 11 oxygenated PACs (O-PACs), and 5 nitrogen PACs (N-PACs). Results showed significant differences between the two separation methods. In half of the sampling campaigns, PAC concentrations differed from a factor 2 to 30 comparing FT and CFC-collected SPMs. The PAC distributions were also affected by the separation method. FT-collected SPM were enriched in 2-3 ring PACs whereas CFC-collected SPM had PAC distributions dominated by medium to high molecular weight compounds typical of combustion processes. This could be explained by distinct cut-off threshold of the two separation methods and strongly suggested the retention of colloidal and/or fine matter on glass-fiber filters particularly enriched in low molecular PACs. These differences between FT and CFC were not systematic but rather enhanced by high water flow rates.

Simultaneous Determination of 13 Priority Polycyclic Aromatic Hydrocarbons in Tehran’s Tap Water and Water for Injection Samples Using Dispersive Liquid-Liquid Micro Extraction Method and Gas Chromatography-Mass Spectrometry

PubMed Central

Sadeghi, Ramezan; Kobarfard, Farzad; Yazdanpanah, Hassan; Eslamizad, Samira; Bayate, Mitra

2016-01-01

Polycyclic aromatic hydrocarbons (PAHs) are classified as persistent and carcinogenic organic pollutants. PAHs contamination has been reported in water. Many of relevant regulatory bodies such as EU and EPA have regulated the limit levels for PAHs in drinking water. In this study, 13 priority polycyclic aromatic hydrocarbons (PAHs) were determined in tap water samples of Tehran and water for injection. Dispersive liquid-liquid microextraction procedure combined with gas chromatography-mass spectrometry was used for the extraction and determination of PAHs in the samples. Under the optimized conditions, the range of extraction recoveries and relative standard deviations (RSDs) of PAHs in water using internal standard (anthracene-d10) were in the range of 71-90% and 4-16%, respectively. Limit of detection for different PAHs were between 0.03 and 0.1 ngmL-1. The concentration of PAHs in all tap water as well as water for injection samples were lower than the limit of quantification of PAHs. This is the first study addressing the occurrence of PAHs in water for injection samples in Iran using dispersive liquid-liquid micro extraction procedure combined with gas chromatography-mass spectrometry. PMID:27642318

Magnetic solid phase extraction of typical polycyclic aromatic hydrocarbons from environmental water samples with metal organic framework MIL-101 (Cr) modified zero valent iron nano-particles.

PubMed

Zhou, Qingxiang; Lei, Man; Wu, Yalin; Yuan, Yongyong

2017-03-03

Metal-organic framework material has been paid more attention because of its good physical and chemical properties. Nanoscale zero valent iron is also in the center of concern recently. Combination of their merits will give impressive results. Present study firstly synthesized a new magnetic nanomaterial nano-scale zero valent iron-functionalized metal-organic framworks MIL-101 (Fe@MIL-101) by co-precipitation method. The morphology and structure of the as-prepared Fe@MIL-101 were characterized by transmission electron microscopy and X-ray diffraction, etc. The experimental results showed that Fe@MIL-101 earned good adsorption ability to polycyclic aromatic hydrocarbons. The limits of detection of developed magnetic solid phase extraction were all below 0.064μgL -1 and precision can be expressed as relative standard deviation (RSD, %) and which was better than 4.4% (n=6). The real water analysis indicated that the spiked recoveries were satisfied, and Fe@MIL-101 earned excellent reusability. All these demonstrated that Fe@MIL-101 exhibited excellent adsorption capability to polycyclic aromatic hydrocarbons and would be a good adsorbent for development of new monitoring methods for environmental pollutants. Copyright © 2017 Elsevier B.V. All rights reserved.

'No Organics' Zone Circles Pinwheel

NASA Technical Reports Server (NTRS)

2008-01-01

The Pinwheel galaxy, otherwise known as Messier 101, sports bright reddish edges in this new infrared image from NASA's Spitzer Space Telescope. Research from Spitzer has revealed that this outer red zone lacks organic molecules present in the rest of the galaxy. The red and blue spots outside of the spiral galaxy are either foreground stars or more distant galaxies.

The organics, called polycyclic aromatic hydrocarbons, are dusty, carbon-containing molecules that help in the formation of stars. On Earth, they are found anywhere combustion reactions take place, such as barbeque pits and exhaust pipes. Scientists also believe this space dust has the potential to be converted into the stuff of life.

Spitzer found that the polycyclic aromatic hydrocarbons decrease in concentration toward the outer portion of the Pinwheel galaxy, then quickly drop off and are no longer detected at its very outer rim. According to astronomers, there's a threshold at the rim where the organic material is being destroyed by harsh radiation from stars. Radiation is more damaging at the far reaches of a galaxy because the stars there have less heavy metals, and metals dampen the radiation.

The findings help researchers understand how stars can form in these harsh environments, where polycyclic aromatic hydrocarbons are lacking. Under normal circumstances, the polycyclic aromatic hydrocarbons help cool down star-forming clouds, allowing them to collapse into stars. In regions like the rim of the Pinwheel as well as the very early universe stars form without the organic dust. Astronomers don't know precisely how this works, so the rim of the Pinwheel provides them with a laboratory for examining the process relatively close up.

In this image, infrared light with a wavelength of 3.6 microns is colored blue; 8-micron light is green; and 24-micron light is red. All three of Spitzer's instruments were used in the study: the infrared array camera, the multiband imaging photometer and the infrared spectrograph.

Prospective Assessment of Chronic Multisymptom Illness Reporting Possibly Associated with Open-Air Burn Pit Smoke Exposure in Iraq

DTIC Science & Technology

2012-06-01

clearly implicating any specific war exposure as a cause of postwar symptoms, which is noteworthy, given the large and contin- ued military presence in...dioxide, sulfur dioxide, and polycyclic aromatic hydrocarbons are being released in the smoke from the fires, and many are known carcinogens and may cause ...exposure by providing benefits to veterans who self-report this type of exposure and have a variety of health conditions.26 The Millennium Cohort Study was

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

PubMed

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

2003-01-24

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.

Thiol/disulfide homeostasis in asphalt workers.

PubMed

Yilmaz, Ömer Hınç; Bal, Ceylan; Neşelioglu, Salim; Büyükşekerci, Murat; Gündüzöz, Meşide; Eren, Funda; Tutkun, Lutfiye; Yilmaz, Fatma Meric

2016-09-02

The aim of this study was to investigate thiol/disulfide homeostasis in asphalt workers who are exposed to polycyclic aromatic hydrocarbons occupationally. The study was carried out in 34 nonsmoker asphalt workers. Additionally, 35 healthy nonsmoker volunteers were recruited as control group. Thiol and disulfide concentrations were determined using the novel automated measurement method. Levels of urinary 1-OH-pyrene were analyzed by liquid chromatography. Disulfide/thiol ratio was significantly higher in exposed group (p = .034). Also, a positive correlation was detected between disulfide/thiol ratio and 1-OH-pyrene values (r = .249, p = .036). Thiol/disulfide homeostasis was found to be disturbed in asphalt workers. The novel test used in this study may be useful for evaluating the oxidative status in polycyclic aromatic hydrocarbon (PAH) exposure.

Modeling the unidentified infrared emission with combinations of polycyclic aromatic hydrocarbons

NASA Technical Reports Server (NTRS)

Allamandola, L. J.; Hudgins, D. M.; Sandford, S. A.

1999-01-01

The infrared emission band spectrum associated with many different interstellar objects can be modeled successfully by using combined laboratory spectra of neutral and positively charged polycyclic aromatic hydrocarbons (PAHs). These model spectra, shown here for the first time, alleviate the principal spectroscopic criticisms previously leveled at the PAH hypothesis and demonstrate that mixtures of free molecular PAHs can indeed account for the overall appearance of the widespread interstellar infrared emission spectrum. Furthermore, these models give us insight into the structures, stabilities, abundances, and ionization balance of the interstellar PAH population. These, in turn, reflect conditions in the emission zones and shed light on the microscopic processes involved in the carbon nucleation, growth, and evolution in circumstellar shells and the interstellar medium.

Use of antioxidant enzymes of clam Ruditapes philippinarum as biomarker to polycyclic aromatic hydrocarbon pollution

NASA Astrophysics Data System (ADS)

Zhu, Lin; Tang, Xuexi; Wang, Ying; Sui, Yadong; Xiao, Hui

2016-03-01

The typical organic pollutant polycyclic aromatic hydrocarbon (PAH) anthracene was selected as a contaminant to investigate its effects on the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the clam Ruditapes philippinarum. The results show that SOD, CAT and GSH-Px had diff erent induction and inhibition reactions to anthracene stress, and that three diff erent organs in R. philippinarum (visceral mass, muscle tissue and mantle) had diff erent sensitivities to anthracene stress. This study suggest that SOD activities of the visceral mass, CAT activitities of the mantle and the visceral mass, and GSH-Px activity of the muscle tissue could be used as sensitive indicators of anthracene stress in R. philippinarum.

Polycyclic aromatic hydrocarbon-DNA adducts in Beluga whales from the Arctic

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

Mathieu, A.; Payne, J.F.; Fancey, L.L.

1997-09-01

The Arctic is still relatively pristine in nature, but it is also vulnerable to pollution because contaminants originating from midlatitudes are transported to the Arctic by atmospheric processes, ocean currents, and river. Recognition of this fact of Arctic vulnerability has resulted in a Declaration on the Protection of the Arctic Environment by eight Arctic countries. A manifest aim of this declaration is to develop an Arctic Monitoring and Assessment Program. We report here on the presence of measurable levels of polycyclic aromatic hydrocarbon-DNA adducts, including relatively high levels in Arctic beluga (Delphinapterus leucas). These results lend support to the valuemore » of developing biological assessment programs for Arctic wildlife. 15 refs., 1 tab.« less

Impact of Inoculation Protocols, Salinity, and pH on the Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) and Survival of PAH-Degrading Bacteria Introduced into Soil

PubMed Central

Kästner, Matthias; Breuer-Jammali, Maren; Mahro, Bernd

1998-01-01

Degradation of polycyclic aromatic hydrocarbons (PAHs) and survival of bacteria in soil was investigated by applying different inoculation protocols. The soil was inoculated with Sphingomonas paucimobilis BA 2 and strain BP 9, which are able to degrade anthracene and pyrene, respectively. CFU of soil bacteria and of the introduced bacteria were monitored in native and sterilized soil at different pHs. Introduction with mineral medium inhibited PAH degradation by the autochthonous microflora and by the strains tested. After introduction with water (without increase of the pore water salinity), no inhibition of the autochthonous microflora was observed and both strains exhibited PAH degradation. PMID:9435090

Laboratory investigation of the contribution of complex aromatic/aliphatic polycyclic hybrid molecular structures to interstellar ultraviolet extinction and infrared emission

NASA Technical Reports Server (NTRS)

Arnoult, K. M.; Wdowiak, T. J.; Beegle, L. W.

2000-01-01

We have demonstrated by experiment that, in an energetic environment, a simple polycyclic aromatic hydrocarbon (PAH) such as naphthalene will undergo chemical reactions that produce a wide array of more complex species (an aggregate). For a stellar wind of a highly evolved star (post-asymptotic giant branch [post-AGB]), this process would be in addition to what is expected from reactions occurring under thermodynamic equilibrium. A surprising result of that work was that produced in substantial abundance are hydrogenated forms that are hybrids of polycyclic aromatic and polycyclic alkanes. Infrared spectroscopy described here reveals a spectral character for these materials that has much in common with that observed for the constituents of circumstellar clouds of post-AGB stars. It can be demonstrated that a methylene (-CH2-) substructure, as in cycloalkanes, is the likely carrier of the 6.9 microns band emission of dust that has recently been formed around IRAS 22272+5433, NGC 7027, and CPD -56 8032. Ultraviolet spectroscopy previously done with a lower limit of 190 nm had revealed that this molecular aggregate can contribute to the interstellar extinction feature at 2175 angstroms. We have now extended our UV spectroscopy of these materials to 110 nm by a vacuum ultraviolet technique. That work, described here, reveals new spectral characteristics and describes how material newly formed during the late stages of stellar evolution could have produced an extinction feature claimed to exist at 1700 angstroms in the spectrum of HD 145502 and also how the newly formed hydrocarbon material would be transformed/aged in the general interstellar environment. The contribution of this molecular aggregate to the rise in interstellar extinction at wavelengths below 1500 angstroms is also examined. The panspectral measurements of the materials produced in the laboratory, using plasmas of H, He, N, and O to convert the simple PAH naphthalene to an aggregate of complex species, provide insight into possible molecular structure details of newly formed hydrocarbon-rich interstellar dust and its transformation into aged material that becomes resident in the interstellar medium. Specifically the presence of naphthalene-like and butadiene-like conjugated structures as chromophores for the 2175 angstroms ultraviolet extinction feature is indicated.

Closed-Shell Polycyclic Aromatic Hydrocarbon Cations: A New Category of Interstellar Polycyclic Aromatic Hydrocarbons

NASA Technical Reports Server (NTRS)

Hudgins, Douglas M.; Bauschlicher, Charles W., Jr.; Allamandola, Louis J.; DeVincenzi, Donald (Technical Monitor)

2001-01-01

Density functional theory has been employed to calculate the harmonic frequencies and intensities of a range of polycyclic aromatic hydrocarbon (PAH) cations that explore both size and electronic structure effects of the infrared spectroscopic properties of these species. The sample extends the size range of PAH species considered to more than 50 carbon atoms and includes several representatives from each of two heretofore unexplored categories of PAH cations: (1) fully benzenoid PAH cations whose carbon skeleton is composed of an odd number of carbon atoms (C(sub odd) PAHs); and (2) protonated PAH cations (HPAH+). Unlike the radical electronic structures of the PAH cations that have been the subject of previous theoretical and experimental work, the species in these two classes have a closed-shell electronic configuration. The calculated spectra of circumcoronene, C54H18 in both neutral and (radical) cationic form are also reported and compared with those of the other species. Overall, the C(sub odd) PAHs spectra are dominated by strong CC stretching modes near 1600 cm(exp -1) and display spectra that are remarkably insensitive to molecular size. The HPAH+ species evince a more complex spectrum consistent with the added contributions of aliphatic modes and their generally lower symmetry. Finally, for both classes of closed-shell cations, the intensity of the aromatic CH stretching modes is found to increase with molecular size far out of proportion with the number of CH groups, approaching a value more typical of neutral PAHs for the largest species studied.

Biotransformation of petroleum asphaltenes and high molecular weight polycyclic aromatic hydrocarbons by Neosartorya fischeri.

PubMed

Hernández-López, E Lorena; Perezgasga, Lucia; Huerta-Saquero, Alejandro; Mouriño-Pérez, Rosa; Vazquez-Duhalt, Rafael

2016-06-01

Neosartorya fischeri, an Aspergillaceae fungus, was evaluated in its capacity to transform high molecular weight polycyclic aromatics hydrocarbons (HMW-PAHs) and the recalcitrant fraction of petroleum, the asphaltenes. N. fischeri was able to grow in these compounds as sole carbon source. Coronene, benzo(g,h,i)perylene, and indeno(1,2,3-c,d)pyrene, together with the asphaltenes, were assayed for fungal biotransformation. The transformation of the asphaltenes and HMW-PAHs was confirmed by reverse-phase high-performance liquid chromatography (HPLC), nano-LC mass spectrometry, and IR spectrometry. The formation of hydroxy and ketones groups on the PAH molecules suggest a biotransformation mediated by monooxygenases such as cytochrome P450 system (CYP). A comparative microarray with the complete genome from N. fischeri showed three CYP monooxygenases and one flavin monooxygenase genes upregulated. These findings, together with the internalization of aromatic substrates into fungal cells and the microsomal transformation of HMW-PAHs, strongly support the role of CYPs in the oxidation of these recalcitrant compounds.

[Polycyclic aromatic hydrocarbons (PAHs) in herbs and fruit teas].

PubMed

Ciemniak, Artur

2005-01-01

Polycyclic aromatic hydrocarbons (PAHs) of which benzo[a]pyrene is the most commonly studied and measured, are fused - ring aromatic compounds formed in both natural and man made processes and are found widely distributed throughout the human environment. PAHs occur as contaminants in different food categories and beverages including water, vegetables, fruit, cereals, oils and fats, barbecued and smoked meat. The sources of PAHs in food are predominantly from environmental pollution and food processing. PAHs emissions from automobile traffic and industry activities were show to influence the PAHs levels in vegetables and fruits. The present study was carried out to determine levels of 16 basic PAHs in herbs and fruit teas. The method was based on the hexane extraction and cleaned up by florisil cartridge. The extracts were analysed by GC-MS. The levels of total PAHs varied from 48,27 microg/kg (hibiscus tea) to 1703 microg/kg (green tea). The highest level of BaP was found in lime tea (74,2 microg/kg).

Effect of pyrolysis temperature on polycyclic aromatic hydrocarbons toxicity and sorption behaviour of biochars prepared by pyrolysis of paper mill effluent treatment plant sludge.

PubMed

Devi, Parmila; Saroha, Anil K

2015-09-01

The polycyclic aromatic hydrocarbons (PAHs) toxicity and sorption behaviour of biochars prepared from pyrolysis of paper mill effluent treatment plant (ETP) sludge in temperature range 200-700 °C was studied. The sorption behaviour was found to depend on the degree of carbonization where the fractions of carbonized and uncarbonized organic content in the biochar act as an adsorption media and partition media, respectively. The sorption and partition fractions were quantified by isotherm separation method and isotherm parameters were correlated with biochar properties (aromaticity, polarity, surface area, pore volume and ash content). The risk assessment for the 16 priority EPA PAHs present in the biochar matrix was performed and it was found that the concentrations of the PAHs in the biochar were within the permissible limits prescribed by US EPA (except BC400 and BC500 for high molecular weight PAHs). Copyright © 2015 Elsevier Ltd. All rights reserved.

Birds and polycyclic aromatic hydrocarbons

USGS Publications Warehouse

Albers, P.H.

2006-01-01

Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.

Polycyclic aromatic hydrocarbon degradation by biosurfactant-producing Pseudomonas sp. IR1.

PubMed

Kumara, Manoj; Leon, Vladimir; De Sisto Materano, Angela; Ilzins, Olaf A; Galindo-Castro, Ivan; Fuenmayor, Sergio L

2006-01-01

We characterized a newly isolated bacterium, designated as IR1, with respect to its ability to degrade polycyclic aromatic hydrocarbons (PAHs) and to produce biosurfactants. Isolated IR1 was identified as Pseudomonas putida by analysis of 16S rRNA sequences (99.6% homology). It was capable of utilizing two-, three- and four-ring PAHs but not hexadecane and octadecane as a sole carbon and energy source. PCR and DNA hybridization studies showed that enzymes involved in PAH metabolism were related to the naphthalene dioxygenase pathway. Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by IR1 during growth on both water miscible and immiscible substrates. The biosurfactants lowered the surface tension of medium from 54.9 dN cm(-1) to 35.4 dN cm(-1) and formed a stable and compact emulsion with an emulsifying activity of 74% with diesel oil, when grown on dextrose. These findings indicate that this isolate may be useful for bioremediation of sites contaminated with aromatic hydrocarbons.

Occurrences, composition profiles and source identifications of polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ship ballast sediments.

PubMed

Su, Peng-Hao; Lv, Bao-Yi; Tomy, Gregg T; Xu, Jin-Xiang; Tian, Wen; Hou, Chun-Yan; Yin, Fang; Li, Yi-Fan; Feng, Dao-Lun

2017-02-01

The aim of this study was to investigate the levels of persistent organic pollutants (POPs) including polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ship ballast sediments. The ballast sediment samples were collected from six merchant ships docked in 2015 in Jiangyin City, China. Ballast sediments represent a potential vector for the transport of POPs and invasive species between marine environments. An attempt was also made to determine the sources of these compounds in the ballast sediment. The results indicated ballast sediments generally contain greater amounts of BDE-209 and comparable amounts of PAHs, PBDEs (exclusive of BDE-209) and PCBs compared to those in marine surface sediments. Based on the sediment quality guidelines, PAHs and PCBs in ballast sediments were estimated to have median or high potential of posing ecological risks, respectively, to marine life if ballast sediments were disposed without specific treatment. POPs in ballast sediments were derived from multiple sources with atmospheric deposition being an important origin. Ship activities including diesel exhaust and illegal oil sewage discharge were considerable contributors of certain individual POPs to ballast sediments. Our study is important because it represents the first report on levels, health risk assessment and source apportionments of POPs in ballast sediments and is a first step in the implementation of specific ballast sediment management measures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comprehensive Chemical Characterization of Rapé Tobacco Products: Nicotine, Un-ionized Nicotine, Tobacco-specific N’-Nitrosamines, Polycyclic Aromatic Hydrocarbons, and Flavor Constituents

PubMed Central

Stanfill, Stephen B.; da Silva, André Luiz Oliveira; Lisko, Joseph G.; Lawler, Tameka S.; Kuklenyik, Peter; Tyx, Robert E.; Peuchen, Elizabeth H.; Richter, Patricia; Watson, Clifford H.

2017-01-01

Rapé, a diverse group of smokeless tobacco products indigenous to South America, is generally used as a nasal snuff and contains substantial amount of plant material with or without tobacco. Previously uncharacterized, rapé contains addictive and harmful chemicals that may have public health implications for users. Here we report % moisture, pH and the levels of total nicotine, un-ionized nicotine, flavor-related compounds, tobacco-specific N-nitrosamines (TSNAs) and polycyclic aromatic hydrocarbons (PAHs) for manufactured and hand-made rapé. Most rapé products were mildly acidic (pH 5.17 – 6.23) with total nicotine ranging from 6.32 to 47.6 milligram per gram of sample (mg/g). Calculated un-ionized nicotine ranged from 0.03 to 18.5 mg/g with the highest values associated with hand-made rapés (pH 9.75 – 10.2), which contain alkaline ashes. In tobacco-containing rapés, minor alkaloid levels and Fourier transform infrared spectra were used to confirm the presence of Nicotiana rustica, a high nicotine tobacco species. There was a wide concentration range of TSNAs and PAHs among the rapés analyzed. Several TSNAs and PAHs identified in the products are known or probable carcinogens according to the International Agency for Research in Cancer. Milligram quantities of some non-tobacco constituents, such as camphor, coumarin, and eugenol, warrant additional evaluation. PMID:25934468

Comprehensive chemical characterization of Rapé tobacco products: Nicotine, un-ionized nicotine, tobacco-specific N'-nitrosamines, polycyclic aromatic hydrocarbons, and flavor constituents.

PubMed

Stanfill, Stephen B; Oliveira da Silva, André Luiz; Lisko, Joseph G; Lawler, Tameka S; Kuklenyik, Peter; Tyx, Robert E; Peuchen, Elizabeth H; Richter, Patricia; Watson, Clifford H

2015-08-01

Rapé, a diverse group of smokeless tobacco products indigenous to South America, is generally used as a nasal snuff and contains substantial amount of plant material with or without tobacco. Previously uncharacterized, rapé contains addictive and harmful chemicals that may have public health implications for users. Here we report % moisture, pH, and the levels of total nicotine, un-ionized nicotine, flavor-related compounds, tobacco-specific N-nitrosamines (TSNAs) and polycyclic aromatic hydrocarbons (PAHs) for manufactured and hand-made rapé. Most rapé products were mildly acidic (pH 5.17-6.23) with total nicotine ranging from 6.32 to 47.6 milligram per gram of sample (mg/g). Calculated un-ionized nicotine ranged from 0.03 to 18.5 mg/g with the highest values associated with hand-made rapés (pH 9.75-10.2), which contain alkaline ashes. In tobacco-containing rapés, minor alkaloid levels and Fourier transform infrared spectra were used to confirm the presence of Nicotiana rustica, a high nicotine tobacco species. There was a wide concentration range of TSNAs and PAHs among the rapés analyzed. Several TSNAs and PAHs identified in the products are known or probable carcinogens according to the International Agency for Research on Cancer. Milligram quantities of some non-tobacco constituents, such as camphor, coumarin, and eugenol, warrant additional evaluation. Published by Elsevier Ltd.

Indoor-outdoor levels of size segregated particulate matter and mono/polycyclic aromatic hydrocarbons among urban areas using solid fuels for heating

NASA Astrophysics Data System (ADS)

Kliucininkas, Linas; Krugly, Edvinas; Stasiulaitiene, Inga; Radziuniene, Inga; Prasauskas, Tadas; Jonusas, Arunas; Kauneliene, Violeta; Martuzevicius, Dainius

2014-11-01

Emissions from the fuel combustion in the energy production are causes of concern due to associated health risks, but little information is available on the impact of residential fuel burning on indoor air quality, where most of the human exposure occurs. In this complex study, concentrations of size-segregated particulate matter (PM), monocyclic and polycyclic aromatic compounds (MAHs and PAHs) at indoor and outdoor sites in six urban homes in the city of Kaunas, Lithuania, were determined over winter and summer sampling campaigns, specifically targeting the impact of the local fuel burning to the indoor air quality. PM levels observed in Kaunas during winter measurement campaign were higher compared to those in many other European settlements utilizing biomass for energy production. The particle size distribution analysis revealed that the major part of the PM mass in winter period consisted of fine particles (PM2.5). Both MAH and PAH levels were higher in winter. The indoor to outdoor ratios (I/O) of MAHs and PAHs revealed specific patterns depending on the presence of emissions sources indoors. Irrespectively of the season, I/O values were <1, suggesting that in case of the absence of an indoor pollution, the dominant source of organic compounds was from the outdoor environment. In homes with no PAH source inside, the I/O ratio equalled ranged from 0.05 to 0.36, suggesting the penetrated portion of outdoor combustion particles to the indoor air.

Analysis of polycyclic aromatic hydrocarbons in tree-rings of Masson pine (Pinus massoniana L.) from two industrial sites in the Pearl River Delta, south China.

PubMed

Kuang, Yuan-wen; Zhou, Guo-yi; Wen, Da-zhi; Li, Jiong; Sun, Fang-fang

2011-09-01

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were examined and potential sources of PAHs were identified from the dated tree-rings of Masson pine (Pinus massoniana L.) near two industrial sites (Danshuikeng, DSK and Xiqiaoshan, XQS) in the Pearl River Delta of south China. Total concentrations of PAHs (∑PAHs) were revealed with similar patterns of temporal trends in the tree-rings at both sites, suggesting tree-rings recorded the historical variation in atmospheric PAHs. The differences of individual PAHs and of ∑PAHs detected in the tree-rings between the two sites reflected the historical differences of airborne PAHs. Regional changes in industrial activities might contribute to the site-specific and period-specific patterns of the tree-ring PAHs. The diagnostic PAH ratios of Ant/(Ant + PA), FL/(FL + Pyr), and BaA/(BaA + Chr)) revealed that PAHs in the tree-rings at both sites mainly stemmed from the combustion process (pyrogenic sources). Principal component analysis further confirmed that wood burning, coal combustion, diesel, and gasoline-powered vehicular emissions were the dominant contributors of PAHs sources at DSK, while diesel combustion, gasoline and natural gas combustion, and incomplete coal combustion were responsible for the main origins of PAHs at XQS. Tree-ring analysis of PAHs was indicative of PAHs from a mixture of sources of combustion, thus minimizing the bias of short-term active air sampling.

Fungal lactone ring opening of 6', 7'-dihydroxybergamottin diminishes cytochrome P450 3A4 inhibitory activity

USDA-ARS?s Scientific Manuscript database

Furanocoumarins (FCs) are a class of aromatic compounds in grapefruit that inhibit human intestinal cytochrome P450 3A4 (CYP3A4). Since fungi metabolize polycyclic aromatic hydrocarbons, we hypothesized that certain fungi might also metabolize FCs into forms that may be inactive as CYP3A4 inhibitors...

Chemical fingerprinting applied to the evaluation of marine oil pollution in the coasts of Canary Islands (Spain).

PubMed

Peña-Méndez, E M; Astorga-España, M S; García-Montelongo, F J

2001-01-01

Chemical fingerprinting approach to environmental assessment is illustrated in the evaluation of marine oil pollution in the coasts using two limpet species as bioindicator organisms, and based on profiles and concentrations of n-alkanes and aromatic hydrocarbons in their tissues. Accidental and chronic releases of hydrocarbons can contaminate the marine environment of the Canary Islands not only because of their geographical situation but also because of the very dense tanker traffic around. This situation affects coastal areas, fishing activities, tourism resort, etc. Concentrations of n-alkanes and aromatic hydrocarbons (polycyclic aromatic hydrocarbons and methyl-polycyclic aromatic hydrocarbons) in the soft tissues of the marine intertidal and subtidal limpets, Patella crenata and Patella ullysiponensis aspera, were evaluated. Limpet samples were collected at monthly intervals, at three locations on the southeast coast of Tenerife over a 3-year period (1991-93). Levels of hydrocarbons found in limpets are similar to concentrations found in unpolluted areas around the world. From application of principal component analysis, the interpretation of variable loading plots gives information on variable correlation and can be used to distinguish among potential sources of pollution and the ability of studied molluscs to be used as bioindicator organisms.

Emission factors of polycyclic and nitro-polycyclic aromatic hydrocarbons from residential combustion of coal and crop residue pellets.

PubMed

Yang, Xiaoyang; Liu, Shijie; Xu, Yisheng; Liu, Yu; Chen, Lijiang; Tang, Ning; Hayakawa, Kazuichi

2017-12-01

Polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) are toxic pollutants mainly produced during fossil fuel combustion. Domestic coal stoves, which emit large amounts of PAHs and NPAHs, are widely used in the Chinese countryside. In this study, emission factors (Efs) for 13 PAH species and 21 NPAH species for four raw coal (three bituminous and one anthracite), one honeycomb briquette, and one crop residue pellet (peanut hulls) samples burned in a typical Chinese rural cooking stove were determined experimentally. The PAH and NPAH Efs for the six fuels were 3.15-49 mg/kg and 0.32-100 μg/kg, respectively. Peanut hulls had very high Efs for both PAHs and NPAHs, and honeycomb briquettes had the lowest Efs. 2-Nitropyrene and 2-nitrofluoranthene, which are NPAHs typically found in secondary organic aerosol, were detected in the emissions from some fuels, suggesting that chemical reactions may have occurred in the dilution tunnel between the flue gas leaving the stove and entering the sampler. The 1-nitropyrene to pyrene diagnostic ratios for coal and peanut hulls were 0.0001 ± 0.0001 and 0.0005, respectively. These were in the same order of magnitude as reference ratios for emissions during coal combustion. The 6-nitrobenzo[a]pyrene to benzo[a]pyrene ratios for the fuels were determined, and the ratios for coal and peanut hulls were 0.0010 ± 0.0001 and 0.0014, respectively. The calculated potential toxic risks indicated that peanut hull emissions were very toxic, especially in terms of NPAHs, compared with emissions from the other fuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stigmastane and hopanes as conserved biomarkers for estimating oil biodegradation in a former refinery plant-contaminated soil.

PubMed

Gagni, Simona; Cam, Darinn

2007-05-01

In the last decade, a refinery plant located in Lido Adriano, East Ravenna (Italy) has been subject to mineral oil contamination. The mineral crude oil, extracted from the offshore in Adriatic sea, consisted of 78% aliphatics, cyclic alkanes and saturated polycyclic hydrocarbons, 9% aromatics, polycyclic aromatic hydrocarbons (PAHs) and alkylated derivatives, and 13% of tars/asphaltenes. Analysis of soil after 10 years of natural attenuation revealed a complete depletion of linear (n-C(9)-C(24)), light aromatics (C1-C3/benzenes) and PAHs (C2/naphthalene, C1/phenanthrene); besides a substantial degradation of isoprenoids prystane and phytane, branched and cyclic alkanes. The remaining contaminants which withstood to natural degradation was saturated polycyclic hydrocarbons (perhydro-PAH derivatives), unsaturated polycyclic hydrocarbons (tetrahydro, dihydro-PAH derivatives), terpanes, steranes and unidentified compounds. Such residues resulted in 80% reduction of its concentration after two months of laboratory treatment. Samples were extracted by organic solvents, separated by silica/alumina gel column chromatography and analyzed by gas chromatography-mass selective detector (GC-MSD). Identification and quantification of aliphatic, cyclic alkanes, typical PAHs, terpanes and steranes were carried out to chromatograms of M/Z=85, 83, individual M/Zs, M/Z=191 and 217, respectively. The present work shows that, among numerous biomarkers present in the source oil, stigmastane and two isomers of hopane showed invariable concentrations after laboratory experiments that mimic natural biodegradation in the field, so they can be used as conserved internal biomarkers. These are very useful tools to assess alterations in less stable classes of saturated compounds contained in petroleum. Marked degradation of perhydro, tetrahydro, dihydro-PAH derivatives in the laboratory treatment has been evidenced.

Global atmospheric emissions and transport of polycyclic aromatic hydrocarbons: Evaluation of modeling and transboundary pollution

NASA Astrophysics Data System (ADS)

Shen, Huizhong; Tao, Shu

2014-05-01

Global atmospheric emissions of 16 polycyclic aromatic hydrocarbons (PAHs) from 69 major sources were estimated for a period from 1960 to 2030. Regression models and a technology split method were used to estimated country and time specific emission factors, resulting in a new estimate of PAH emission factor variation among different countries and over time. PAH emissions in 2007 were spatially resolved to 0.1° × 0.1° grids based on a newly developed global high-resolution fuel combustion inventory (PKU-FUEL-2007). MOZART-4 (The Model for Ozone and Related Chemical Tracers, version 4) was applied to simulate the global tropospheric transport of Benzo(a)pyrene, one of the high molecular weight carcinogenic PAHs, at a horizontal resolution of 1.875° (longitude) × 1.8947° (latitude). The reaction with OH radical, gas/particle partitioning, wet deposition, dry deposition, and dynamic soil/ocean-air exchange of PAHs were considered. The simulation was validated by observations at both background and non-background sites, including Alert site in Canadian High Arctic, EMEP sites in Europe, and other 254 urban/rural sites reported from literatures. Key factors effecting long-range transport of BaP were addressed, and transboundary pollution was discussed.

Hollow mesoporous carbon spheres-based fiber coating for solid-phase microextraction of polycyclic aromatic hydrocarbons.

PubMed

Hu, Xingru; Liu, Chao; Li, Jiansheng; Luo, Rui; Jiang, Hui; Sun, Xiuyun; Shen, Jinyou; Han, Weiqing; Wang, Lianjun

2017-10-20

In this study, a novel hollow mesoporous carbon spheres-based fiber (HMCSs-F) was fabricated to immobilize HMCSs onto a stainless steel wire for solid-phase microextraction (SPME). Characterization results showed that the HMCSs-F possessed a large specific surface area, high porosity and uniform pore size. To demonstrate the extraction performance, a series of polycyclic aromatic hydrocarbons (PAHs) was chosen as target analytes. The experimental parameters including extraction and desorption conditions were optimized. Compared to commercial fibers, the HMCSs-F exhibited better extraction efficiency for PAHs. More interestingly, a good extraction selectivity for PAHs from the complex matrix was observed in these HMCSs-F. The enhanced SPME performance was attributed to the unique pore structure and special surface properties of the HMCSs. Furthermore, under the optimum conditions, the limits of detection (LODs) for the HMCSs-F were in the range of 0.20-1.15ngL -1 with a corresponding relative standard deviation that was below 8.6%. The method was successfully applied for the analysis of PAHs in actual environmental water samples with recoveries ranging from 85.9% to 112.2%. These results imply that the novel HMCSs-F have potential application in environmental water analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of 16 polycyclic aromatic hydrocarbons in seawater using molecularly imprinted solid-phase extraction coupled with gas chromatography-mass spectrometry.

PubMed

Song, Xingliang; Li, Jinhua; Xu, Shoufang; Ying, Rongjian; Ma, Jiping; Liao, Chunyang; Liu, Dongyan; Yu, Junbao; Chen, Lingxin

2012-09-15

A method of solid-phase extraction (SPE) using molecularly imprinted polymers (MIPs) as adsorbent coupled with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of 16 types of polycyclic aromatic hydrocarbons (PAHs) in seawater samples. The MIPs were prepared through non-covalent polymerization by using the 16 PAHs mixture as a template based on sol-gel surface imprinting. Compared with the non-imprinted polymers (NIPs), the MIPs exhibited excellent affinity towards 16 PAHs with binding capacity of 111.0-195.0 μg g(-1), and imprinting factor of 1.50-3.12. The significant binding specificity towards PAHs even in the presence of environmental parameters such as dissolved organic matter and various metal ions, suggested that this new imprinting material was capable of removing 93.2% PAHs in natural seawater. High sensitivity was attained, with the low limits of detection for 16 PAHs in natural seawater ranging from 5.2-12.6 ng L(-1). The application of MIPs with high affinity and excellent stereo-selectivity toward PAHs in SPE might offer a more attractive alternative to conventional sorbents for extraction and abatement of PAH-contaminated seawater. Copyright © 2012 Elsevier B.V. All rights reserved.

Removing polycyclic aromatic hydrocarbons from water using granular activated carbon: kinetic and equilibrium adsorption studies.

PubMed

Eeshwarasinghe, Dinushika; Loganathan, Paripurnanda; Kalaruban, Mahatheva; Sounthararajah, Danious Pratheep; Kandasamy, Jaya; Vigneswaran, Saravanamuthu

2018-05-01

Polycyclic aromatic hydrocarbons (PAHs) constitute a group of highly persistent, toxic and widespread environmental micropollutants that are increasingly found in water. A study was conducted in removing five PAHs, specifically naphthalene, acenaphthylene, acenaphthene, fluorene and phenanthrene, from water by adsorption onto granular activated carbon (GAC). The pseudo-first-order (PFO) model satisfactorily described the kinetics of adsorption of the PAHs. The Weber and Morris diffusion model's fit to the data showed that there were faster and slower rates of intra-particle diffusion probably into the mesopores and micropores of the GAC, respectively. These rates were negatively related to the molar volumes of the PAHs. Batch equilibrium adsorption data fitted well to the Langmuir, Freundlich and Dubinin-Radushkevich models, of which the Freundlich model exhibited the best fit. The adsorption affinities were related to the hydrophobicity of the PAHs as determined by the log K ow values. Free energies of adsorption calculated from the Dubinin-Radushkevich model and the satisfactory kinetic data fitting to the PFO model suggested physical adsorption of the PAHs. Adsorption of naphthalene, acenaphthylene and acenaphthene in fixed-bed columns containing a mixture of GAC (0.5 g) + sand (24.5 g) was satisfactorily simulated by the Thomas model.

Sensitive determination of polycyclic aromatic hydrocarbons in water samples by HPLC coupled with SPE based on graphene functionalized with triethoxysilane.

PubMed

Huang, Ke-Jing; Li, Jing; Liu, Yan-Ming; Wang, Lan

2013-02-01

The graphene functionalized with (3-aminopropyl) triethoxysilane was synthesized by a simple hydrothermal reaction and applied as SPE sorbents to extract trace polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. These sorbents possess high adsorption capacity and extraction efficiency due to strong adsorption ability of carbon materials and large specific surface area of nanoparticles, and only 10 mg of sorbents are required to extract PAHs from 100 mL water samples. Several condition parameters, such as eluent and its volume, adsorbent amount, sample volume, sample pH, and sample flow rate, were optimized to achieve good sensitivity and precision. Under the optimized extraction conditions, the method showed good linearity in the range of 1-100 μg/L, repeatability of the extraction (the RSDs were between 1.8 and 2.9%, n = 6), and satisfactory detection limits of 0.029-0.1 μg/L. The recoveries of PAHs spiked in environmental water samples ranged from 84.6 to 109.5%. All these results demonstrated that this new SPE technique was a viable alternative to conventional enrichment techniques for the extraction and analysis of PAHs in complex samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reinforced microextraction of polycyclic aromatic hydrocarbons from polluted soil samples using an in-needle coated fiber with polypyrrole/graphene oxide nanocomposite.

PubMed

Behfar, Mina; Ghiasvand, Ali Reza; Yazdankhah, Fatemeh

2017-07-01

The surface of a stainless-steel wire was platinized using electrophoretic deposition method to create a high-surface-area with porous and cohesive substrate. The platinized fiber was coated by the polypyrrole/graphene oxide nanocomposite by electropolymerization and accommodated into a stainless-steel needle to fabricate an in-needle coated fiber. The developed setup was coupled to gas chromatography with flame ionization detection and applied to extract and determine polycyclic aromatic hydrocarbons (naphthalene, fluorene, phenanthrene, fluoranthene, and pyrene) in complicated solid matrices, along with reinforcement of the extraction by cooling the sorbent, using liquid carbon dioxide. To obtain the best extraction efficiency, the important experimental variables including extraction temperature and time, temperature of cooled sorbent, sampling flow rate, and desorption condition were studied. Under the optimal condition, limits of detection for five studied analytes were in the range of 0.2-0.8 pg/g. Linear dynamic ranges for the calibration curves were found to be in the range of 0.001-1000 ng/g. Relative standard deviations obtained for six replicated analyses of 1 ng/g of analytes were 4.9-13.5%. The reinforced in-needle coated fiber method was successfully applied for the analysis of polycyclic aromatic hydrocarbons in contaminated soil samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of a dispersive liquid-liquid microextraction method using a lighter-than-water ionic liquid for the analysis of polycyclic aromatic hydrocarbons in water.

PubMed

Medina, Giselle S; Reta, Mario

2016-11-01

A dispersive liquid-liquid microextraction method using a lighter-than-water phosphonium-based ionic liquid for the extraction of 16 polycyclic aromatic hydrocarbons from water samples has been developed. The extracted compounds were analyzed by liquid chromatography coupled to fluorescence/diode array detectors. The effects of several experimental parameters on the extraction efficiency, such as type and volume of ionic liquid and disperser solvent, type and concentration of salt in the aqueous phase and extraction time, were investigated and optimized. Three phosphonium-based ionic liquids were assayed, obtaining larger extraction efficiencies when trihexyl-(tetradecyl)phosphonium bromide was used. The optimized methodology requires a few microliters of a lighter-than-water phosphonium-based ionic liquid, which allows an easy separation of the extraction solvent phase. The obtained limits of detection were between 0.02 and 0.56 μg/L, enrichment factors between 109 and 228, recoveries between 60 and 108%, trueness between 0.4 and 9.9% and reproducibility values between 3 and 12% were obtained. These figures of merit combined with the simplicity, rapidity and low cost of the analytical methodology indicate that this is a viable and convenient alternative to the methods reported in the literature. The developed method was used to analyze polycyclic aromatic hydrocarbons in river water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Air-water partition coefficients for a suite of polycyclic aromatic and other C10 through C20 unsaturated hydrocarbons.

PubMed

Rayne, Sierra; Forest, Kaya

2016-09-18

The air-water partition coefficients (Kaw) for 86 large polycyclic aromatic hydrocarbons and their unsaturated relatives were estimated using high-level G4(MP2) gas and aqueous phase calculations with the SMD, IEFPCM-UFF, and CPCM solvation models. An extensive method validation effort was undertaken which involved confirming that, via comparisons to experimental enthalpies of formation, gas-phase energies at the G4(MP2) level for the compounds of interest were at or near thermochemical accuracy. Investigations of the three solvation models using a range of neutral and ionic compounds suggested that while no clear preferential solvation model could be chosen in advance for accurate Kaw estimates of the target compounds, the employment of increasingly higher levels of theory would result in lower Kaw errors. Subsequent calculations on the polycyclic aromatic and unsaturated hydrocarbons at the G4(MP2) level revealed excellent agreement for the IEFPCM-UFF and CPCM models against limited available experimental data. The IEFPCM-UFF-G4(MP2) and CPCM-G4(MP2) solvation energy calculation approaches are anticipated to give Kaw estimates within typical experimental ranges, each having general Kaw errors of less than 0.5 log10 units. When applied to other large organic compounds, the method should allow development of a broad and reliable Kaw database for multimedia environmental modeling efforts on various contaminants.

Evaluation of the phototoxicity of unsubstituted and alkylated polycyclic aromatic hydrocarbons to mysid shrimp (Americamysis bahia): Validation of predictive models.

PubMed

Finch, Bryson E; Marzooghi, Solmaz; Di Toro, Dominic M; Stubblefield, William A

2017-08-01

Crude oils are composed of an assortment of hydrocarbons, some of which are polycyclic aromatic hydrocarbons (PAHs). Polycyclic aromatic hydrocarbons are of particular interest due to their narcotic and potential phototoxic effects. Several studies have examined the phototoxicity of individual PAHs and fresh and weathered crude oils, and several models have been developed to predict PAH toxicity. Fingerprint analyses of oils have shown that PAHs in crude oils are predominantly alkylated. However, current models for estimating PAH phototoxicity assume toxic equivalence between unsubstituted (i.e., parent) and alkyl-substituted compounds. This approach may be incorrect if substantial differences in toxic potency exist between unsubstituted and substituted PAHs. The objective of the present study was to examine the narcotic and photo-enhanced toxicity of commercially available unsubstituted and alkylated PAHs to mysid shrimp (Americamysis bahia). Data were used to validate predictive models of phototoxicity based on the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap approach and to develop relative effect potencies. Results demonstrated that photo-enhanced toxicity increased with increasing methylation and that phototoxic PAH potencies vary significantly among unsubstituted compounds. Overall, predictive models based on the HOMO-LUMO gap were relatively accurate in predicting phototoxicity for unsubstituted PAHs but are limited to qualitative assessments. Environ Toxicol Chem 2017;36:2043-2049. © 2017 SETAC. © 2017 SETAC.

Removal of polycyclic aromatic hydrocarbons in soil spiked with model mixtures of petroleum hydrocarbons and heterocycles using biosurfactants from Rhodococcus ruber IEGM 231.

PubMed

Ivshina, Irina; Kostina, Ludmila; Krivoruchko, Anastasiya; Kuyukina, Maria; Peshkur, Tatyana; Anderson, Peter; Cunningham, Colin

2016-07-15

Removal of polycyclic aromatic hydrocarbons (PAHs) in soil using biosurfactants (BS) produced by Rhodococcus ruber IEGM 231 was studied in soil columns spiked with model mixtures of major petroleum constituents. A crystalline mixture of single PAHs (0.63g/kg), a crystalline mixture of PAHs (0.63g/kg) and polycyclic aromatic sulfur heterocycles (PASHs), and an artificially synthesized non-aqueous phase liquid (NAPL) containing PAHs (3.00g/kg) dissolved in alkanes C10-C19 were used for spiking. Percentage of PAH removal with BS varied from 16 to 69%. Washing activities of BS were 2.5 times greater than those of synthetic surfactant Tween 60 in NAPL-spiked soil and similar to Tween 60 in crystalline-spiked soil. At the same time, amounts of removed PAHs were equal and consisted of 0.3-0.5g/kg dry soil regardless the chemical pattern of a model mixture of petroleum hydrocarbons and heterocycles used for spiking. UV spectra for soil before and after BS treatment were obtained and their applicability for differentiated analysis of PAH and PASH concentration changes in remediated soil was shown. The ratios A254nm/A288nm revealed that BS increased biotreatability of PAH-contaminated soils. Copyright © 2016 Elsevier B.V. All rights reserved.

[Characteristics of organic pollutants in the sediments from a typical electronics industrial zone].

PubMed

Liu, Jin; Deng, Dai-Yong; Xu, Mei-Ying; Sun, Guo-Ping

2013-03-01

In order to investigate the contamination status of organic pollutants in a river of a typical electrical equipment industrial area, Ronggui, Foshan, the sediments were sampled for the composition, concentration and occurrence analysis of organic pollutants. The polar and non-polar fractionation methods were employed for the fingerprint establishment of organic pollutants. One hundred and seventy-one of organic chemicals including ten categories of alkanes, alkenes, polycyclic aromatic hydrocarbons, benzene, heterocyclic compounds, phthalate esters, aldehydes, ketones, polar compounds, silicon-containing material as well as alkyl esters were examined. The number of different categories of the detected organic pollutants in a descending order was: alkanes > polar compounds > polycyclic aromatic hydrocarbons > aldehydes and ketones > heterocyclic compounds > benzene homologues, phthalate ester > alkyl esters > silicon material > olefins. The abundance of detected organic pollutants in a descending order was: alkanes > polar compounds > alkyl esters > olefins > polycyclic aromatic hydrocarbons > phthalates > silicon material > aldehydes and ketones > heterocyclic compounds > benzene homologues. Among the 51 kinds of alkanes detected, nonadecane accounted for 14.83%, and the persistent organic pollutants accounted for 2.33% of the total organic matter. Compared to similar studies, there were 51 kinds of alkanes and they accounted for 55.5% of the total organic chemicals, showing high diversity and abundance. In addition, some electronics industry-related organic pollutants such as silicone materials were also detected in high frequency.

Distribution of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and organochlorinated pollutants in deep-sea sediments of the Southern Cretan margin, Eastern Mediterranean Sea: a baseline assessment.

PubMed

Mandalakis, Manolis; Polymenakou, Paraskevi N; Tselepides, Anastasios; Lampadariou, Nikolaos

2014-07-01

Deep sediments from the southern Cretan margin were analyzed to establish baseline levels for various types of organic pollutants before the anticipated intensification of anthropogenic activities. The total concentration of aliphatic hydrocarbons (ΣAH:326-3758ngg(-1), dry weight) was similar to those reported for deep sediments of the western Mediterranean Sea, while considerably lower levels were measured for polycyclic aromatic hydrocarbons (ΣPAH:9-60ngg(-1)). Source-diagnostic ratios suggested that the aliphatic hydrocarbons in sediments were mainly of terrestrial biogenic origin, while polycyclic aromatic hydrocarbons stemmed from the deposition of long-range transported combustion aerosols. Among the organochlorinated compounds analyzed, β-hexachlorocyclohexane (β-HCH:222-7052pgg(-1)), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT:37-2236pgg(-1)) and polychlorinated biphenyls (ΣPCB:38-1182pgg(-1)) showed the highest abundance in sediments. The presence of HCHs and PCBs was attributed to historical inputs that have undergone extensive weathering, whereas an ongoing fresh input was suggested for p,p'-DDT. Multiple linear regression analysis revealed that the levels of the various pollutants in sediments were controlled by different factors, but with organic carbon content playing a prominent role in most cases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identification and Quantification of Six-Ring C26H16 Cata-Condensed Polycyclic Aromatic Hydrocarbons in a Complex Mixture of Polycyclic Aromatic Hydrocarbons from Coal Tar

PubMed Central

Oña-Ruales, Jorge O.; Sharma, Arun K.; Wise, Stephen A.

2015-01-01

We applied a combination of normal-phase liquid chromatography (NPLC) with ultraviolet-visible spectroscopy and gas chromatography with mass spectrometry (GC/MS) for the fractionation, identification, and quantification of six ring C26H16 cata-condensed polycyclic aromatic hydrocarbons, PAHs, in the Standard Reference Material 1597a, Complex Mixture of PAHs from Coal Tar. For the characterization analysis, we calculated the GC retention indices of 17 C26H16 PAH authentic reference standards using the Rxi-PAH and DB-5 GC columns. Then, we used NPLC with ultraviolet-visible spectroscopy to isolate the fractions containing the C26H16 PAHs, and subsequently, we used GC/MS to establish the identity and quantity of the C26H16 PAHs using authentic reference standards. Following this procedure, 12 C26H16 cata-condensed PAHs benzo[c]pentaphene, dibenzo[f,k]tetraphene, benzo[h]pentaphene, dibenzo[a,l]tetracene, dibenzo[c,k]tetraphene, naphtho[2,3-c]tetraphene, dibenzo[a,c]tetracene, benzo[b]picene, dibenzo[a,j]tetracene, naphtho[2,1-a]tetracene, dibenzo[c,p]chrysene, and dibenzo[a,f]tetraphene were identified and quantified for the first time, and benzo[c]picene was quantified for the first time in an environmental combustion sample. PMID:26449848

Determination and Distribution of Polycyclic Aromatic Hydrocarbons in Rivers, Sediments and Wastewater Effluents in Vhembe District, South Africa

PubMed Central

Edokpayi, Joshua N.; Odiyo, John O.; Popoola, Oluwaseun E.; Msagati, Titus A. M.

2016-01-01

Polycyclic aromatic hydrocarbons are very toxic and persistent environmental contaminants. This study was undertaken to assess the concentrations and possible sources of 16 PAHs (Polycyclic aromatic hydrocarbons) classified by the United State Environmental Protection Agency as priority pollutants in water and sediments of the Mvudi and Nzhelele Rivers. Effluents from Thohoyandou wastewater treatment plant and Siloam waste stabilization ponds were also investigated. Diagnostic ratios were used to evaluate the possible sources of PAHs. PAHs in the water samples were extracted using 1:1 dichloromethane and n-hexane mixtures, while those in the sediment samples were extracted with 1:1 acetone and dichloromethane using an ultrasonication method. The extracts were purified using an SPE technique and reconstituted in n-hexane before analyses with a gas chromatograph time of flight—mass spectrometer. The results obtained indicate the prevalence of high molecular weight PAHs in all the samples. PAHs concentrations in water and sediment samples from all the sampling sites were in the range of 13.174–26.382 mg/L and 27.10–55.93 mg/kg, respectively. Combustion of biomass was identified as the major possible source of PAHs. Effluents from wastewater treatment facilities were also considered as major anthropogenic contributions to the levels of PAHs found in both river water and sediments. Mvudi and Nzhelele Rivers show moderate to high contamination level of PAHs. PMID:27043597

Monohydroxylated polycyclic aromatic hydrocarbons influence spicule formation in the early development of sea urchins (Hemicentrotus pulcherrimus).

PubMed

Suzuki, Nobuo; Ogiso, Shouzo; Yachiguchi, Koji; Kawabe, Kimi; Makino, Fumiya; Toriba, Akira; Kiyomoto, Masato; Sekiguchi, Toshio; Tabuchi, Yoshiaki; Kondo, Takashi; Kitamura, Kei-ichiro; Hong, Chun-Sang; Srivastav, Ajai K; Oshima, Yuji; Hattori, Atsuhiko; Hayakawa, Kazuichi

2015-05-01

We previously demonstrated that monohydroxylated polycyclic aromatic hydrocarbons (OHPAHs), which are metabolites of polycyclic aromatic hydrocarbons (PAHs), act on calcified tissue and suppress osteoblastic and osteoclastic activity in the scales of teleost fish. The compounds may possibly influence other calcified tissues. Thus, the present study noted the calcified spicules in sea urchins and examined the effect of both PAHs and OHPAHs on spicule formation during the embryogenesis of sea urchins. After fertilization, benz[a]anthracene (BaA) and 4-hydroxybenz[a]anthracene (4-OHBaA) were added to seawater at concentrations of 10(-8) and 10(-7) M and kept at 18 °C. The influence of the compound was given at the time of the pluteus larva. At this stage, the length of the spicule was significantly suppressed by 4-OHBaA (10(-8) and 10(-7) M). BaA (10(-7) M) decreased the length of the spicule significantly, while the length did not change with BaA (10(-8) M). The expression of mRNAs (spicule matrix protein and transcription factors) in the 4-OHBaA (10(-7) M)-treated embryos was more strongly inhibited than were those in the BaA (10(-7) M)-treated embryos. This is the first study to demonstrate that OHPAHs suppress spicule formation in sea urchins. Copyright © 2015 Elsevier Inc. All rights reserved.

Bacterial Degradation of Aromatic Compounds

PubMed Central

Seo, Jong-Su; Keum, Young-Soo; Li, Qing X.

2009-01-01

Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms. PMID:19440284

Dispersants as Used in Response to the MC252-Spill Lead to Higher Mobility of Polycyclic Aromatic Hydrocarbons in Oil-Contaminated Gulf of Mexico Sand

PubMed Central

Zuijdgeest, Alissa; Huettel, Markus

2012-01-01

After the explosion of the Deepwater Horizon oil rig, large volumes of crude oil were washed onto and embedded in the sandy beaches and sublittoral sands of the Northern Gulf of Mexico. Some of this oil was mechanically or chemically dispersed before reaching the shore. With a set of laboratory-column experiments we show that the addition of chemical dispersants (Corexit 9500A) increases the mobility of polycyclic aromatic hydrocarbons (PAHs) in saturated permeable sediments by up to two orders of magnitude. Distribution and concentrations of PAHs, measured in the solid phase and effluent water of the columns using GC/MS, revealed that the mobility of the PAHs depended on their hydrophobicity and was species specific also in the presence of dispersant. Deepest penetration was observed for acenaphthylene and phenanthrene. Flushing of the columns with seawater after percolation of the oiled water resulted in enhanced movement by remobilization of retained PAHs. An in-situ benthic chamber experiment demonstrated that aromatic hydrocarbons are transported into permeable sublittoral sediment, emphasizing the relevance of our laboratory column experiments in natural settings. We conclude that the addition of dispersants permits crude oil components to penetrate faster and deeper into permeable saturated sands, where anaerobic conditions may slow degradation of these compounds, thus extending the persistence of potentially harmful PAHs in the marine environment. Application of dispersants in nearshore oil spills should take into account enhanced penetration depths into saturated sands as this may entail potential threats to the groundwater. PMID:23209777

Polycyclic aromatic hydrocarbon metabolic network in Mycobacterium vanbaalenii PYR-1.

PubMed

Kweon, Ohgew; Kim, Seong-Jae; Holland, Ricky D; Chen, Hongyan; Kim, Dae-Wi; Gao, Yuan; Yu, Li-Rong; Baek, Songjoon; Baek, Dong-Heon; Ahn, Hongsik; Cerniglia, Carl E

2011-09-01

This study investigated a metabolic network (MN) from Mycobacterium vanbaalenii PYR-1 for polycyclic aromatic hydrocarbons (PAHs) from the perspective of structure, behavior, and evolution, in which multilayer omics data are integrated. Initially, we utilized a high-throughput proteomic analysis to assess the protein expression response of M. vanbaalenii PYR-1 to seven different aromatic compounds. A total of 3,431 proteins (57.38% of the genome-predicted proteins) were identified, which included 160 proteins that seemed to be involved in the degradation of aromatic hydrocarbons. Based on the proteomic data and the previous metabolic, biochemical, physiological, and genomic information, we reconstructed an experiment-based system-level PAH-MN. The structure of PAH-MN, with 183 metabolic compounds and 224 chemical reactions, has a typical scale-free nature. The behavior and evolution of the PAH-MN reveals a hierarchical modularity with funnel effects in structure/function and intimate association with evolutionary modules of the functional modules, which are the ring cleavage process (RCP), side chain process (SCP), and central aromatic process (CAP). The 189 commonly upregulated proteins in all aromatic hydrocarbon treatments provide insights into the global adaptation to facilitate the PAH metabolism. Taken together, the findings of our study provide the hierarchical viewpoint from genes/proteins/metabolites to the network via functional modules of the PAH-MN equipped with the engineering-driven approaches of modularization and rationalization, which may expand our understanding of the metabolic potential of M. vanbaalenii PYR-1 for bioremediation applications.

Polycyclic aromatic hydrocarbons associated with airborne particulate matter at a Pathumthani location, 40 km north of Bangkok, Thailand

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

Oanh, N.T.K.; Reutergardh, L.B.; Dung, N.T.

Total suspended particulate matter in ambient air was sampled by high volume samplers at four sites at the Asian Institute of Technology campus, west of the Phahonyothin Road, Phathumthani Province, 40 km North of Bangkok, Thailand. The concentrations of 18 polycyclic aromatic hydrocarbons (PAHs), were measured by gas liquid chromatography with flame ionization and/or liquid solid chromatography with fluorescence detection. The PAH profile with relatively high concentrations of benzo(ghi)perylene and coronene, decreasing with the distance from the road, suggested a substantial contribution from the traffic. The concentrations in the core of the campus were compatible to those reported for residentialmore » areas in Bangkok, but higher than some western metropolitan areas.« less

[Preliminary determination of organic pollutants in agricultural fertilizers].

PubMed

Mo, Ce-hui; Li, Yun-hui; Cai, Quan-ying; Zeng, Qiao-yun; Wang, Bo-guang; Li, Hai-qin

2005-05-01

Organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) in agricultural fertilizers are new problem deserved more study. Eight kinds of organic pollutants including 43 compounds classified as US EPA priority pollutants in twenty one agricultural fertilizers which were universally used in China were determined by Gas chromatography-mass spectrum (GC-MS). Three kinds of organic pollutants including more than 5 compounds were detected in most fertilizers, composing mainly of phthalic acid esters (PAEs), nitrobenzenes (NBs) and polycyclic aromatic hydrocarbons (PAHs). There were 26 compounds detected in at least one fertilizer, five of them especially PAEs detected in most fertilizer and even in all fertilizers. Benzo(a)pyrene, a strongly carcinogenic compound was detected in two fertilizers. Higher concentrations of compounds were determined in those fertilizers such as multifunction compound fertilizers and coated fertilizers.

Macondo-1 well oil-derived polycyclic aromatic hydrocarbons in mesozooplankton from the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Mitra, Siddhartha; Kimmel, David G.; Snyder, Jessica; Scalise, Kimberly; McGlaughon, Benjamin D.; Roman, Michael R.; Jahn, Ginger L.; Pierson, James J.; Brandt, Stephen B.; Montoya, Joseph P.; Rosenbauer, Robert J.; Lorenson, Thomas D.; Wong, Florence L.; Campbell, Pamela L.

2012-01-01

Mesozooplankton (>200 μm) collected in August and September of 2010 from the northern Gulf of Mexico show evidence of exposure to polycyclic aromatic hydrocarbons (PAHs). Multivariate statistical analysis revealed that distributions of PAHs extracted from mesozooplankton were related to the oil released from the ruptured British Petroleum Macondo-1 (M-1) well associated with the R/V Deepwater Horizon blowout. Mesozooplankton contained 0.03-97.9 ng g-1 of total PAHs and ratios of fluoranthene to fluoranthene + pyrene less than 0.44, indicating a liquid fossil fuel source. The distribution of PAHs isolated from mesozooplankton extracted in this study shows that the 2010 Deepwater Horizon spill may have contributed to contamination in the northern Gulf of Mexico ecosystem.

[Sources analysis and contribution identification of polycyclic aromatic hydrocarbons in indoor and outdoor air of Hangzhou].

PubMed

Liu, Y; Zhu, L; Wang, J; Shen, X; Chen, X

2001-11-01

Twelve polycyclic aromatic hydrocarbons (PAHs) were measured in eight homes in Hangzhou during the summer and autumn in 1999. The sources of PAHs and the contributions of the sources to the total concentration of PAHs in the indoor air were identified by the combination of correlation analysis, factor analysis and multiple regression, and the equations between the concentrations of PAHs in indoor and outdoor air and factors were got. It was indicated that the factors of PAHs in the indoor air were domestic cuisine, the volatility of the mothball, cigarette smoke and heating, the waste gas from vehicles. In the smokers' home, cigarette smoke was the most important factor, and it contributed 25.8% of BaP to the indoor air of smokers' home.

The anomalous 3.43 and 3.53 micron emission features toward HD 97048 and Elias 1 - C-C vibrational modes of polycyclic aromatic hydrocarbons?

NASA Technical Reports Server (NTRS)

Schutte, W. A.; Tielens, A. G. G. M.; Allamandola, L. J.; Wooden, D. H.; Cohen, M.

1990-01-01

The 5-8 micron spectra obtained toward the two protostellar sources, HD 97048 and Elias 1 exhibit strong anomalous emission features at 3.43 and 3.53 microns. Combining these results with earlier data established that the emission in the general IR features is extended on at least a 20-arcsec scale. In view of the high energy density in the emission zone, as well as the apparent correspondence of the anomalous 3.43 and 3.53 micron features with weak emission shoulders associated with the general family of IR emission bands, an explanation for these observations in terms of C-C overtones and combination tones of large or dehydrogenated polycyclic aromatic hydrocarbons is judged to be provisionally suitable.

Polycyclic Aromatic Hydrocarbons and Infrared Astrophysics with Spitzer

NASA Technical Reports Server (NTRS)

Hudgins, Douglas M.; Allamandola, L. J.

2004-01-01

Over the past fifteen years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role that carbon-rich plays in the interstellar medium (ISM). Twenty years ago, the possible existence of an abundant population of large, carbon-rich molecules in the ISM was unthinkable. Today, the unmistakable spectroscopic signatures of polycyclic aromatic hydrocarbons (PAHs) - shockingly large molecules by the standards of traditional interstellar chemistry -are recognized throughout the Universe. In this presentation, we will examine the current state of the interstellar PAH model and explore how this data, in conjunction with the unparalleled observational data provided by the Spitzer Space Telescope, can be used to draw ever-deeper insights into the physical and chemical natures of a wide range of astrophysical environments.

Combustion kinetics and emission characteristics of polycyclic aromatic hydrocarbons from polylactic acid combustion.

PubMed

Chien, Yi-Chi; Liang, Chenju; Liu, Shou-Heng; Yang, Shu-Hua

2010-07-01

This study investigates the combustion kinetics and emission factors of 16 U.S. Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs) in polylactic acid (PLA) combustion. Experimentally, two reactions are involved in the PLA combustion process that potentially result in the release of lactide, acetaldehyde, and n-hexaldehyde. The products may continuously be oxidized to form carbon dioxide (CO2) and some PAHs produced because of incomplete combustion. The analytical results indicate that the emission factors for PAHs are in the range of not detectable to 98.04 microg/g. The emission factors are much lower than those of poly(ethylene terephalate) (PET) and other combustion of plastics. Results from this work suggest that combustion is a good choice for waste PLA disposal.

Photoionization of Benzene and Small Polycyclic Aromatic Hydrocarbons in Ultraviolet-Processed Astrophysical Ices: A Computational Study

NASA Technical Reports Server (NTRS)

Woon, D. E.; Park, J.-Y.

2004-01-01

We employed density functional theory (DFT) calculations to model the photoionization behavior of benzene and small polycyclic aromatic hydrocarbons when they are embedded in a matrix of water ice in order to investigate issues raised by recent experimental work by Gudipati and Allamandola. The ionization energies of benzene, naphthalene, anthracene, and pyrene were found to be lowered by 1.5-2.1 eV in water ice. Low-lying vertical electronic excitation energies were computed with time-dependent DFT for both neutral and ionized species and are found in both cases to be remarkably unaffected by the ice matrix. Chemical behavior in ultraviolet-photoprocessed ices is also discussed, with a focus on electron recombination and pathways leading to phenol and analogous products.

Distribution, Source, and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Surface Sediment of Liaodong Bay, Northeast China

NASA Astrophysics Data System (ADS)

Xu, Shuang; Tao, Ping; Li, Yuxia; Guo, Qi; Zhang, Yan; Wang, Man; Jia, Hongliang; Shao, Mihua

2018-01-01

Sixteen polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediments from Liaodong Bay, northeast China. The concentration levels of total PAHs (Σ16PAHs) in sediment were 11.0˜249.6 ng·g-1 dry weight (dw), with a mean value of 89.9 ng·g-1 dry weight (dw). From the point of the spatial distribution, high PAHs levels were found in the western areas of Liaodong Bay. In the paper, sources of PAHs were investigated by diagnostic ratios, which indicated that pyrogenic sources were the main sources of PAHs in the sediment of Liaodong Bay. Therefore, selected PAH levels in sediments were compared with Sediments Quality Guidelines (ERM-ERL indexes) for evaluation probable toxic effects on marine organism.

Macondo-1 well oil-derived polycyclic aromatic hydrocarbons in mesozooplankton from the northern Gulf of Mexico

USGS Publications Warehouse

Mitra, Siddhartha; Kimmel, David G.; Snyder, Jessica; Scalise, Kimberly; McGlaughon, Benjamin D.; Roman, Michael R.; Jahn, Ginger L.; Pierson, James J.; Brandt, Stephen B.; Montoya, Joseph P.; Rosenbauer, Robert J.; Lorenson, T.D.; Wong, Florence L.; Campbell, Pamela L.

2012-01-01

Mesozooplankton (>200 μm) collected in August and September of 2010 from the northern Gulf of Mexico show evidence of exposure to polycyclic aromatic hydrocarbons (PAHs). Multivariate statistical analysis revealed that distributions of PAHs extracted from mesozooplankton were related to the oil released from the ruptured British Petroleum Macondo-1 (M-1) well associated with the R/VDeepwater Horizon blowout. Mesozooplankton contained 0.03–97.9 ng g−1 of total PAHs and ratios of fluoranthene to fluoranthene + pyrene less than 0.44, indicating a liquid fossil fuel source. The distribution of PAHs isolated from mesozooplankton extracted in this study shows that the 2010 Deepwater Horizon spill may have contributed to contamination in the northern Gulf of Mexico ecosystem.

Hydrous pyrolysis of polycyclic aromatic hydrocarbons and implications for the origin of PAH in hydrothermal petroleum

NASA Technical Reports Server (NTRS)

McCollom, T. M.; Simoneit, B. R.; Shock, E. L.

1999-01-01

Polycyclic aromatic hydrocarbons (PAH) are found at high concentrations in thermally altered organic matter and hydrothermally generated petroleum from sediment-covered seafloor hydro-thermal systems. To better understand the factors controlling the occurrence of PAH in thermally altered environments, the reactivities of two PAH, phenanthrene and anthracene, were investigated in hydrothermal experiments. The compounds were heated with water at 330 degrees C in sealed reaction vessels for durations ranging from 1 to 17 days. Iron oxide and sulfide minerals, formic acid, or sodium for-mate were included in some experiments to vary conditions within the reaction vessel. Phenanthrene was unreactive both in water alone and in the presence of minerals for up to 17 days, while anthracene was partially hydrogenated (5-10%) to di- and tetrahydroanthracene. In the presence of 6-21 vol % formic acid, both phenanthrene and anthracene reacted extensively to form hydrogenated and minor methylated derivatives, with the degree of hydrogenation and methylation increasing with the amount of formic acid. Phenanthrene was slightly hydrogenated in sodium formate solutions. The hydrogenation reactions could be readily reversed; heating a mixture of polysaturated phenanthrenes resulted in extensive dehydrogenation (aromatization) after 3 days at 330 degrees C. While the experiments demonstrate that reaction pathways for the hydrogenation of PAH under hydrothermal conditions exist, the reactions apparently require higher concentrations of H2 than are typical of geologic settings. The experiments provide additional evidence that PAH may be generated in hydrothermal systems from progressive aromatization and dealkylation of biologically derived polycyclic precursors such as steroids and terpenoids. Furthermore, the results indicate that PAH initially present in sediments or formed within hydrothermal systems are resistant to further thermal degradation during hydrothermal alteration.

Modulation of ethoxyresorufin O-deethylase and glutathione S-transferase activities in Nile tilapia (Oreochromis niloticus) by polycyclic aromatic hydrocarbons containing two to four rings: implications in biomonitoring aquatic pollution.

PubMed

Pathiratne, Asoka; Hemachandra, Chamini K

2010-08-01

Despite ubiquity of polycyclic aromatic hydrocarbons (PAHs) in the tropical environments, little information is available concerning responses of tropical fish to PAHs and associated toxicity. In the present study, effects of five PAHs containing two to four aromatic rings on hepatic CYP1A dependent ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST) and serum sorbitol dehydrogenase (SDH) activities in Nile tilapia, a potential fish species for biomonitoring pollution in tropical waters, were evaluated. Results showed that EROD activities were induced by the PAHs containing four aromatic rings (pyrene and chrysene) in a dose dependent manner. However PAHs with two to three aromatic rings (naphthalene, phenanthrene and fluoranthene) caused no effect or inhibition of EROD activities depending on the dose and the duration. Fluoranthene was the most potent inhibitor. SDH results demonstrated that high doses of fluoranthene induced hepatic damage. GST activity was induced by the lowest dose of phenanthrene, fluoranthene and chrysene but high doses had no effect. The results indicate that induction of EROD enzyme in Nile tilapia is a useful biomarker of exposure to PAHs such as pyrene and chrysene. However EROD inhibiting PAHs such as fluoranthene in the natural environment may modulate the EROD inducing potential of other PAHs thereby influencing PAH exposure assessments.

Actions of a versatile fluorene-degrading bacterial isolate on polycyclic aromatic compounds.

PubMed Central

Grifoll, M; Selifonov, S A; Gatlin, C V; Chapman, P J

1995-01-01

Pseudomonas cepacia F297 grew with fluorene as a sole source of carbon and energy; its growth yield corresponded to an assimilation of about 40% of fluorene carbon. The accumulation of a ring meta-cleavage product during growth and the identification of 1-indanone in growth media and washed-cell suspensions suggest that strain F297 metabolizes fluorene by mechanisms analogous to those of naphthalene degradation. In addition to fluorene, strain F297 utilized for growth a wide variety of polycyclic aromatic compounds (PACs), including naphthalene, 2,3-dimethylnaphthalene, phenanthrene, anthracene, and dibenzothiophene. Fluorene-induced cells of the strain also transformed 2,6-dimethylnaphthalene, biphenyl, dibenzofuran, acenaphthene, and acenaphthylene. The identification of products formed from those substrates (by gas chromatography-mass spectrometry) in washed-cell suspensions indicates that P. cepacia F297 carries out the following reactions: (i) aromatic ring oxidation and cleavage, apparently using the pyruvate released for growth, (ii) methyl group oxidations, (iii) methylenic oxidations, and (iv) S oxidations of aromatic sulfur heterocycles. Strain F297 grew with a creosote-PAC mixture, producing an almost complete removal of all aromatic compounds containing 2 to 3 rings in 14 days, as demonstrated by gas chromatography analysis of the remaining PACs recovered from cultures. The identification of key chemicals confirmed that not only are certain compounds depleted but also the anticipated reaction products are found. PMID:7487007

Actions of a versatile fluorene-degrading bacterial isolate on polycyclic aromatic compounds.

PubMed

Grifoll, M; Selifonov, S A; Gatlin, C V; Chapman, P J

1995-10-01

Pseudomonas cepacia F297 grew with fluorene as a sole source of carbon and energy; its growth yield corresponded to an assimilation of about 40% of fluorene carbon. The accumulation of a ring meta-cleavage product during growth and the identification of 1-indanone in growth media and washed-cell suspensions suggest that strain F297 metabolizes fluorene by mechanisms analogous to those of naphthalene degradation. In addition to fluorene, strain F297 utilized for growth a wide variety of polycyclic aromatic compounds (PACs), including naphthalene, 2,3-dimethylnaphthalene, phenanthrene, anthracene, and dibenzothiophene. Fluorene-induced cells of the strain also transformed 2,6-dimethylnaphthalene, biphenyl, dibenzofuran, acenaphthene, and acenaphthylene. The identification of products formed from those substrates (by gas chromatography-mass spectrometry) in washed-cell suspensions indicates that P. cepacia F297 carries out the following reactions: (i) aromatic ring oxidation and cleavage, apparently using the pyruvate released for growth, (ii) methyl group oxidations, (iii) methylenic oxidations, and (iv) S oxidations of aromatic sulfur heterocycles. Strain F297 grew with a creosote-PAC mixture, producing an almost complete removal of all aromatic compounds containing 2 to 3 rings in 14 days, as demonstrated by gas chromatography analysis of the remaining PACs recovered from cultures. The identification of key chemicals confirmed that not only are certain compounds depleted but also the anticipated reaction products are found.

[Morphological features of tissue reactions in combined treatment of experimental tuberculosis induced by xenobiotics].

PubMed

Pavlov, V A; Kazak, T I; Kleĭn, A V; Nosova, N A

1995-01-01

The trend to aggravated running and contribution of air pollution of large industrial centers with polycyclic aromatic hydrocarbons (PAH) to tuberculosis onset and progress dictate the necessity of the search for new treatment methods. The authors made an attempt to treat experimental tuberculosis with sodium glutamate and isoniazide under chronic exposure to PAH dust. Sodium glutamate especially in combination with isoniazide produces a good effect enhancing granulomatous reactions fibroplastic processes in the foci of specific inflammation. Sodium glutamate is thought an effective pathogenetic treatment of tuberculosis.

Biologically important compounds in synfuels processes

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

Clark, B R; Ho, C; Griest, W H

1980-01-01

Crude products, by-products and wastes from synfuel processes contain a broad spectrum of chemical compounds - many of which are active in biological systems. Discerning which compound classes are most important is necessary in order to establish effective control over release or exposure. Polycyclic aromatic hydrocarbons (PAH), multialkylated PAH, primary aromatic amines and N-heterocyclic PAH are significant contributors to the overall mutagenic activities of a large number of materials examined. Ames test data show that the basic, primary aromatic amine fraction is the most active. PAHs, multialkylated PAHs and N-heterocyclic PAHs are all components of the neutral fraction. In nearlymore » all cases, the neutral fractions contribute the largest portion of the mutagenic activity, while the basic primary aromatic amine fractions have the highest specific activity. Neutral fractions are usually the largest (wt %) whereas the total basic fractions are small by comparison; thus, the overall greater contribution of the neutral fraction to the mutagenic activity of most samples. Biologically active constituents are isolated in preparative scale amounts from complex mixtures utilizing combinations of liquid-liquid extraction and various liquid chromatographic column-eluant combinations. Fractions are characterized using a combination of spectroscopic techniques and gas chromatography/mass spectrometry.« less

Bright Lights, Green City

NASA Image and Video Library

2010-07-28

Two extremely bright stars illuminate a greenish mist in this image from the new GLIMPSE360 survey from NASA Spitzer Space Telescope. The fog is comprised of hydrogen and carbon compounds called polycyclic aromatic hydrocarbons.

Ingredients for Life Artist Concept

NASA Image and Video Library

2005-07-27

This artist conception symbolically represents complex organic molecules, known as polycyclic aromatic hydrocarbons, seen in the early universe. These large molecules, comprised of carbon and hydrogen, are considered among the building blocks of life.

ISO Mid-Infrared Spectra of Reflection Nebulae

NASA Technical Reports Server (NTRS)

Werner, M.; Uchida, K.; Sellgren, K.; Houdashelt, M.

1999-01-01

Our goal is to test predictions of models attributing the IEFs to polycyclic aromatic hydrocarbons (PAHs). Interstellar models predict PAHs change from singly ionized to neutral as the UV intensity, Go, decreases.

Early-life cockroach allergen and polycyclic aromatic hydrocarbon exposures predict cockroach sensitization among inner-city children

PubMed Central

Perzanowski, Matthew S.; Chew, Ginger L.; Divjan, Adnan; Jung, Kyung Hwa; Ridder, Robert; Tang, Deliang; Diaz, Diurka; Goldstein, Inge F.; Kinney, Patrick L.; Rundle, Andrew G.; Camann, David E.; Perera, Frederica P.; Miller, Rachel L.

2013-01-01

Background Sensitization to cockroach is one of the strongest identified risk factors for greater asthma morbidity in low-income, urban communities; however, the timing of exposures relevant to development of sensitization has not been elucidated fully. Further, exposure to combustion byproducts, including polycyclic aromatic hydrocarbons (PAHs), may augment the development of allergic sensitization. Objective To test the hypotheses that domestic cockroach allergen measured prenatally would predict cockroach sensitization in early childhood, and that this association would be greater for children exposed to higher concentrations of PAHs. Methods Dominican and African-American pregnant women living in NYC were enrolled. In the third trimester, expectant mothers wore personal air samplers for measurement of 8 nonvolatile PAHs and the semi-volatile PAH pyrene, and dust was collected from homes for allergen measurement. Glutathione-s-transferase mu (GSTM1) gene polymorphisms were measured in children. Allergen-specific IgE was measured from the children at ages 2, 3, 5 and 7 years. Results Bla g2 in prenatal kitchen dust predicted cockroach sensitization at age 5–7 years [adjusted relative risk (RR) 1.15; P = 0.001; n = 349]. The association was observed only among children above [RR 1.22; P = 0.001], but not below [RR 1.07; P = 0.24] median sum of 8 nonvolatile PAH levels. The association was most pronounced among children with higher PAH and null in the GSTM1 gene [RR 1.54; P = 0.001]. Conclusions Prenatal exposure to cockroach allergen was associated with a greater risk of developing allergic sensitization. This risk was increased by exposure to nonvolatile PAHs, with children null for the GSTM1 mutation particularly vulnerable. Key messages Domestic exposure to cockroach allergen measured prenatally predicted sensitization to cockroach at age 5–7 years. Cockroach allergen predicted sensitization only among children also exposed to higher levels of airborne non-volatile polycyclic aromatic hydrocarbons, indicating that these combustion byproducts may act as adjuvants in the development of cockroach sensitization in urban environments. These findings suggest that targeting either allergen or combustion sources with primary prevention could be successful in reducing the development of cockroach sensitization. PMID:23391330

On-road traffic emissions of polycyclic aromatic hydrocarbons and their oxy- and nitro- derivative compounds measured in road tunnel environments.

PubMed

Keyte, Ian J; Albinet, Alexandre; Harrison, Roy M

2016-10-01

Vehicular emissions are a key source of polycyclic aromatic compounds (PACs), including polycyclic aromatic hydrocarbons (PAHs) and their oxygenated (OPAH) and nitrated (NPAH) derivatives, in the urban environment. Road tunnels are a useful environment for the characterisation of on-road vehicular emissions, providing a realistic traffic fleet and a lack of direct sunlight, chemical reactivity and non-traffic sources. In the present investigation the concentrations of selected PAHs, OPAHs and NPAHs have been measured in the Parc des Princes Tunnel in Paris (PdPT, France), and at the Queensway Road Tunnel and an urban background site in Birmingham (QT, U.K). A higher proportion of semi-volatile (3-4 ring) PAH, OPAH and NPAH compounds are associated with the particulate phase compared with samples from the ambient environment. A large (~85%) decline in total PAH concentrations is observed between 1992 and 2012 measurements in QT. This is attributed primarily to the introduction of catalytic converters in the U.K as well as increasingly stringent EU vehicle emissions legislation. In contrast, NPAH concentrations measured in 2012 are similar to those measured in 1996. This observation, in addition to an increased proportion of (Phe+Flt+Pyr) in the observed PAH burden in the tunnel, is attributed to the increased number of diesel passenger vehicles in the U.K during this period. Except for OPAHs, comparable PAH and NPAH concentrations are observed in both investigated tunnels (QT and PdP). Significant differences are shown for specific substances between PAC chemical profiles in relation with the national traffic fleet differences (33% diesel passenger cars in U.K. vs 69% in France and up to 80% taking into account all vehicle categories). The dominating and sole contribution of 1-Nitropyrene observed in the PdPT NPAH profile strengthens the promising use of this compound as a diesel exhaust marker for PM source apportionment studies. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.

Removal of polycyclic aromatic hydrocarbons from aqueous solution by raw and modified plant residue materials as biosorbents.

PubMed

Xi, Zemin; Chen, Baoliang

2014-04-01

Removal of polycyclic aromatic hydrocarbons (PAHs), e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents for organic pollutant abatement. Bamboo wood, pine wood, pine needles and pine bark were selected as plant residues, and acid hydrolysis was used as an easily modification method. The raw and modified biosorbents were characterized by elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorption isotherms of PAHs to raw biosorbents were apparently linear, and were dominated by a partitioning process. In comparison, the isotherms of the hydrolyzed biosorbents displayed nonlinearity, which was controlled by partitioning and the specific interaction mechanism. The sorption kinetic curves of PAHs to the raw and modified plant residues fit well with the pseudo second-order kinetics model. The sorption rates were faster for the raw biosorbents than the corresponding hydrolyzed biosorbents, which was attributed to the latter having more condensed domains (i.e., exposed aromatic core). By the consumption of the amorphous cellulose component under acid hydrolysis, the sorption capability of the hydrolyzed biosorbents was notably enhanced, i.e., 6-18 fold for phenanthrene, 6-8 fold for naphthalene and pyrene and 5-8 fold for acenaphthene. The sorption coefficients (Kd) were negatively correlated with the polarity index [(O+N)/C], and positively correlated with the aromaticity of the biosorbents. For a given biosorbent, a positive linear correlation between logKoc and logKow for different PAHs was observed. Interestingly, the linear plots of logKoc-logKow were parallel for different biosorbents. These observations suggest that the raw and modified plant residues have great potential as biosorbents to remove PAHs from wastewater. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2013-06-01

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

Theoretical Study of the Electronic Spectra of a Polycyclic Aromatic Hydrocarbon, Naphthalene, and its Derivatives

NASA Technical Reports Server (NTRS)

Du, Ping; Salama, Farid; Loew, Gilda H.

1993-01-01

In order to preselect possible candidates for the origin of diffuse interstellar bands observed, semiempirical quantum mechanical method INDO/S was applied to the optical spectra of neutral, cationic, and anionic states of naphthalene and its hydrogen abstraction and addition derivatives. Comparison with experiment shows that the spectra of naphthalene and its ions were reliably predicted. The configuration interaction calculations with single-electron excitations provided reasonable excited state wavefunctions compared to ab initio calculations that included higher excitations. The degree of similarity of the predicted spectra of the hydrogen abstraction and derivatives to those of naphthalene and ions depends largely on the similarity of the it electron configurations. For the hydrogen addition derivatives, very little resemblance of the predicted spectra to naphthalene was found because of the disruption of the aromatic conjugation system. The relevance of these calculations to astrophysical issues is discussed within the context of these polycyclic aromatic hydrocarbon models. Comparing the calculated electronic energies to the Diffuse Interstellar Bands (DIBs), a list of possible candidates of naphthalene derivatives is established which provides selected candidates for a definitive test through laboratory studies.

Boron nitride nanotubes as novel sorbent for solid-phase microextraction of polycyclic aromatic hydrocarbons in environmental water samples.

PubMed

Fu, Meizhen; Xing, Hanzhu; Chen, Xiangfeng; Zhao, Rusong; Zhi, Chunyi; Wu, Chiman Lawrence

2014-09-01

Boron nitride nanotube (BNNT) is a novel material that shows potential ability in capturing organic pollutants. In this study, BNNTs fixed on a stainless steel fiber by a sol-gel technique were used as sorbent for solid-phase microextraction. Five polycyclic aromatic hydrocarbons with different numbers of aromatic rings were selected as target analysts. Gas chromatography coupled with tandem mass spectrometry was used for detection and quantitative determination. Under optimized conditions, the experimental results show a wide range of linearity (1 to 1,000 ng L(-1)), less than 10.1 % repeatability of relative standard deviation, and low detection limits (0.08 to 0.39 ng L(-1)). In addition, the fabricated fiber offered good thermal and chemical stability. The proposed method was successfully applied for the analysis of real water samples, and satisfactory results were obtained with relative recoveries ranging from 80.2 to 116.8 %. The results demonstrated that BNNTs could be used as sorbent for the analysis of environmental pollutants at trace levels.

Interstellar Polycyclic Aromatic Compounds and Astrophysics

NASA Technical Reports Server (NTRS)

Hodgins, Douglas M.; DeVincenzi, Donald (Technical Monitor)

1999-01-01

Polycyclic aromatic compounds (PACs), a class of organic molecules whose structures are characterized by the presence of two or more fused aromatic rings, have been the subject of astrophysical interest for nearly two decades. Large by interstellar standards (from as few as 20 to perhaps as many as several hundred atoms), it has been suggested that these species are among the most abundant interstellar molecules impacting a wide range of astrophysical phenomena including: the ubiquitous family of infrared emission bands observed in an ever-increasing assortment of astronomical objects; the subtle but rich array of discrete visible/near-infrared interstellar molecular absorption features known as the diffuse interstellar bands (DIBs); the broad near-infrared quasi-continuum observed in a number of nebulae known as excess red emission (ERE); the interstellar ultraviolet extinction curve and broad '2200 Angstrom bump'; the heating/cooling mechanisms of interstellar clouds. Nevertheless, until recently a lack of good-quality laboratory spectroscopic data on PACs under astrophysically relevant conditions (i.e. isolated, ionized molecules; ionized molecular clusters, etc.) has hindered critical evaluation and extension of this model

Polycyclic aromatic hydrocarbons (PAH) formation from the pyrolysis of different municipal solid waste fractions.

PubMed

Zhou, Hui; Wu, Chunfei; Onwudili, Jude A; Meng, Aihong; Zhang, Yanguo; Williams, Paul T

2015-02-01

The formation of 2-4 ring polycyclic aromatic hydrocarbons (PAH) from the pyrolysis of nine different municipal solid waste fractions (xylan, cellulose, lignin, pectin, starch, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET)) were investigated in a fixed bed furnace at 800 °C. The mass distribution of pyrolysis was also reported. The results showed that PS generated the most total PAH, followed by PVC, PET, and lignin. More PAH were detected from the pyrolysis of plastics than the pyrolysis of biomass. In the biomass group, lignin generated more PAH than others. Naphthalene was the most abundant PAH, and the amount of 1-methynaphthalene and 2-methynaphthalene was also notable. Phenanthrene and fluorene were the most abundant 3-ring PAH, while benzo[a]anthracene and chrysene were notable in the tar of PS, PVC, and PET. 2-ring PAH dominated all tar samples, and varied from 40 wt.% to 70 wt.%. For PS, PET and lignin, PAH may be generated directly from the aromatic structure of the feedstock. Copyright © 2014 Elsevier Ltd. All rights reserved.

Separation and characterization of gall bladder bile metabolites from speckled trout, Salvelinus fontinalis, exposed to individual polycyclic aromatic compounds.

PubMed

Leonard, J D; Hellou, J

2001-03-01

Speckled trout, Salvelinus fontinalis, were orally exposed to individual polycyclic aromatic compounds (PACs) represented by benzo[a]pyrene, carbazole, chrysene, dibenzofuran, dibenzothiophene, fluorene, phenanthrene, and pyrene. Fish were sacrificed 7 d after exposure and the gall bladder removed for bile analysis. High pressure liquid chromatography (HPLC) with fluorescence (F) and ultraviolet (UV) detection was used to determine the presence of PAC derivatives in the bile without pretreatment. Glucuronide conjugates were predominant in all exposures with variable amounts (0-53%) of phenols and starting material. Identification of compounds was confirmed by selective extraction of less polar nonconjugated PACs and enzymatic hydrolysis of water-soluble material. This was followed by HPLC and/or gas chromatography-mass spectrometry (GCMS) characterization of the produced phenols. Total metabolite levels varied widely among compounds.

Determination of polycyclic aromatic hydrocarbons in roasted coffee

PubMed Central

JIMENEZ, ANGELICA; ADISA, AFOLABI; WOODHAM, CARA; SALEH, MAHMOUD

2016-01-01

Polycyclic aromatic hydrocarbons (PAHs) are suspected to be carcinogenic and mutagenic. This study describes the presence of PAHs in light, medium and dark roasted coffee including instant and decaffeinated brands. Total PAHs concentration was related to the degree of roasting with light roasted coffee showing the least and dark roasted coffee showing the highest level. Both instant and decaffeinated coffee brand showed lower levels of PAHs. Naphthalene, acenaphthylene, pyrene and chrysene were the most abundant individual isomers. The concentrations ranged from 0 to 561 ng g−1 for naphthalene, 0 to 512 ng g−1 for acenaphthylene, 60 to 459 ng g−1 for pyrene and 56 to 371 ng g−1 for chrysene. Thus, roasting conditions should be controlled to avoid the formation of PAHs due to their suspected carcinogenic and mutagenic properties. PMID:25190557

From biowaste to magnet-responsive materials for water remediation from polycyclic aromatic hydrocarbons.

PubMed

Nisticò, Roberto; Cesano, Federico; Franzoso, Flavia; Magnacca, Giuliana; Scarano, Domenica; Funes, Israel G; Carlos, Luciano; Parolo, Maria E

2018-07-01

Composted urban biowaste-derived substances (BBS-GC) are used as carbon sources for the preparation of carbon-coated magnet-sensitive nanoparticles obtained via co-precipitation method and the subsequent thermal treatment at 550 °C under nitrogen atmosphere. A multitechnique approach has been applied to investigate the morphology, magnetic properties, phase composition, thermal stability of the obtained magnet-sensitive materials. In particular, pyrolysis-induced modifications affecting the BBS-GC/carbon shell were highlighted. The adsorption capacity of such bio-derivative magnetic materials for the removal of hydrophobic contaminants such as polycyclic aromatic hydrocarbons was evaluated in order to verify their potential application in wastewater remediation process. The promising results suggest their use as a new generation of magnet-responsive easily-recoverable adsorbents for water purification treatments. Copyright © 2018 Elsevier Ltd. All rights reserved.

Airborne polycyclic aromatic hydrocarbons trigger human skin cells aging through aryl hydrocarbon receptor.

PubMed

Qiao, Yuan; Li, Qiang; Du, Hong-Yang; Wang, Qiao-Wei; Huang, Ye; Liu, Wei

2017-07-01

Accumulating evidence suggests that polycyclic aromatic hydrocarbons (PAH) which adsorbed on the surface of ambient air particulate matters (PM), are the major toxic compound to cause cardiovascular and respiratory diseases, even cancer. However, its detrimental effects on human skin cell remain unclear. Here, we demonstrated that SRM1649b, a reference urban dust material of PAH, triggers human skin cells aging through cell cycle arrest, cell growth inhibition and apoptosis. Principally, SRM1649b facilitated Aryl hydrocarbon receptor (AhR) translocated into nucleus, subsequently activated ERK/MAPK signaling pathway, and upregulated aging-related genes expression. Most important, we found that AhR antagonist efficiently revert the aging of skin cells. Thus our novel findings firstly revealed the mechanism of skin aging under PAH contamination and provided potential strategy for clinical application. Copyright © 2017. Published by Elsevier Inc.

DNA-damage effect of polycyclic aromatic hydrocarbons from urban area, evaluated in lung fibroblast cultures.

PubMed

Teixeira, Elba Calesso; Pra, Daniel; Idalgo, Daniele; Henriques, João Antonio Pêgas; Wiegand, Flavio

2012-03-01

This study was designed to biomonitor the effect of PAH extracts from urban areas on the DNA of lung cell cultures. The analyses of the polycyclic aromatic hydrocarbons (PAHs) were performed in atmospheric PM(2.5) and PM(10) collected at three sampling sites with heavy traffic located in the Metropolitan Area of Porto Alegre (MAPA) (Brazil). The concentrations of 16 major PAHs were determined according to EPA. Comet assay on V79 hamster lung cells was chosen for genotoxicity evaluation. Temperature, humidity, and wind speed were recorded. With regard to the damage index, higher levels were reported in the extract of particulate matter samples from the MAPA during the summer. High molecular weight compounds showed correlation with DNA damage frequency and their respective carcinogenicity. Copyright © 2011. Published by Elsevier Ltd.

The anomalous 3. 43 and 3. 53 micron emission features toward HD 97048 and Elias 1 - C-C vibrational modes of polycyclic aromatic hydrocarbons

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

Schutte, W.A.; Tielens, A.G.G.M.; Allamandola, L.J.

1990-09-01

The 5-8 micron spectra obtained toward the two protostellar sources, HD 97048 and Elias 1 exhibit strong anomalous emission features at 3.43 and 3.53 microns. Combining these results with earlier data established that the emission in the general IR features is extended on at least a 20-arcsec scale. In view of the high energy density in the emission zone, as well as the apparent correspondence of the anomalous 3.43 and 3.53 micron features with weak emission shoulders associated with the general family of IR emission bands, an explanation for these observations in terms of C-C overtones and combination tones ofmore » large or dehydrogenated polycyclic aromatic hydrocarbons is judged to be provisionally suitable. 62 refs.« less

Methods for the isolation and identification of polycyclic aromatic hydrocarbons found in complex mixtures and the determination of their possible toxicity by means of a host mediated bioassay technique. Progress report, July 1, 1976--February 1, 1977. [Cultured mouse leumemia cell bioassay system

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

Lipsky, S.R.; Alexander, G.; McMurray, W.

1977-02-01

Techniques were developed to produce excellent high performance glass capillary columns for gas chromatographic analyses of a wide range of complex mixtures of organic compounds, including those containing a wide array of polycyclic aromatic hydrocarbons (PAH) derived from a coal liquefaction process. Work was begun to assess the potential mutogenicity and/or carcinogenicity of the various isolated PAH fractions utilizing a unique host mediated bioassay system. Preliminary results indicate that further efforts will be required to determine dose response parameters of cultured mouse leukemia cells, as well as suitable vehicles for the satisfactory introduction of certain PAH fractions into this particularmore » bioassay system.« less

Polycyclic aromatic hydrocarbons in storm runoff from urban and coastal South Carolina.

PubMed

Ngabe, B; Bidleman, T F; Scott, G I

2000-06-08

Stormwater runoff was collected in urbanized areas of South Carolina to investigate the levels and sources of polycyclic aromatic hydrocarbons (PAHs). Mean concentrations of total PAHs in runoff (sum(PAHs), 14 compounds), determined by gas chromatography-mass spectrometry, were 5590 ng/l in the city of Columbia and 282 ng/l in the coastal community of Murrells Inlet. Lower concentrations were found in estuarine water at Murrells Inlet (mean = 35 ng/l) and at undeveloped North Inlet estuary (13 ng/l). The PAH profiles in Columbia and Murrells Inlet runoff were similar to those of atmospheric particulate matter and unlike those in used crankcase oil. Examination of the aliphatic fraction of Columbia runoff samples by gas chromatography with flame ionization detection showed patterns that were more similar to used crankcase oil than to urban aerosols.

THE NASA AMES POLYCYCLIC AROMATIC HYDROCARBON INFRARED SPECTROSCOPIC DATABASE: THE COMPUTED SPECTRA

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

Bauschlicher, C. W.; Ricca, A.; Boersma, C.

The astronomical emission features, formerly known as the unidentified infrared bands, are now commonly ascribed to polycyclic aromatic hydrocarbons (PAHs). The laboratory experiments and computational modeling done at the NASA Ames Research Center to create a collection of PAH IR spectra relevant to test and refine the PAH hypothesis have been assembled into a spectroscopic database. This database now contains over 800 PAH spectra spanning 2-2000 {mu}m (5000-5 cm{sup -1}). These data are now available on the World Wide Web at www.astrochem.org/pahdb. This paper presents an overview of the computational spectra in the database and the tools developed to analyzemore » and interpret astronomical spectra using the database. A description of the online and offline user tools available on the Web site is also presented.« less

NMR shifts for polycyclic aromatic hydrocarbons from first-principles

NASA Astrophysics Data System (ADS)

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

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.

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

USGS Publications Warehouse

Mahler, B.J.; Van Metre, P.C.; Bashara, T.J.; Wilson, J.T.; Johns, D.A.

2005-01-01

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. We 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 with coal-tar emulsion sealcoat had mean concentrations of PAHs of 3500 mg/kg, 65 times higher than the mean concentration from unsealed asphalt and cement lots. Diagnostic ratios of individual PAHs indicating sources are similar for particles from coal-tar emulsion sealed lots and suspended sediment from four urban streams. Contaminant yields projected to the watershed scale for the four associated watersheds indicate that runoff from sealed parking lots could account for the majority of stream PAH loads.

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

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

Jenkins, B.M.

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

Analysis of polycyclic aromatic hydrocarbons in sediment reference materials by microwave-assisted extraction.

PubMed

Shu, Y Y; Lao, R C; Chiu, C H; Turle, R

2000-12-01

The microwave-assisted extraction (MAE) of polycyclic aromatic hydrocarbons (PAHs) from harbor sediment reference material EC-1, marine sediment reference material HS-2 and PAH-spiked river bed soil was conducted. The extraction conditions for EC-1 were carried out at 70 degrees C and 100 degrees C under pressure in closed vessels with cyclohexane acetone (1:1), cyclohexane-water (3:1), hexane acetone (1:1), and hexane-water (3:1) for 10 min. A comparison between MAE and a 16-h Soxhlet extraction (SX) method showed that both techniques gave comparable results with certified values. MAE has advantages over the currently used Soxhlet technique due to a faster extraction time and lower quantity of solvent used. The consumption of organic solvent of the microwave method was less than one-tenth compared to Soxhlet.

Use of the semipermeable membrane device (SPMD) to sample polycyclic aromatic hydrocarbon pollution in a lotic system

USGS Publications Warehouse

Lebo, Jon A.; Zajicek, James L.; Orazio, Carl E.; Petty, Jimmie D.; Huckins, James; Douglas, Ernest H.

1996-01-01

Relative concentrations of aqueous polycyclic aromatic hydrocarbons (PAH) were investigated in an urban creek. Samples were obtained at five sites within a 600-m segment of the creek that is critical habitat for an endangered species of fish. the sampling technique entailed immersion of semipermeable membrane devices (SPMDs) in the water for intervals as long as 64 d. SPMDs are passive, in situ, mtegrative samplers of bioavailable (truly dissolved) PAH and other hydrophobic organic contaminants. Two point sources of PAH to the 600-m segment of the creek were differentiated. Aqueous concentrations were found to wane dramatically over the relatively short section of the creek between the point sources. All samples were almost devoid of alkyl-substituted PAH, indicating that the ultimate sources were probably of pyrogenic nature.

Polycyclic aromatic hydrocarbons in bottom sediment and bioavailability in streams in the New River Gorge National River and Gauley River National Recreation Area, West Virginia, 2002

USGS Publications Warehouse

Messinger, Terrence

2004-01-01

Polycyclic aromatic hydrocarbons (PAHs), including some on the U.S. Environmental Protection Agency's priority pollutant list, were found in bottom sediment in streams in the coal-producing region of the Kanawha River Basin in 1996-1998, and in and near the New River Gorge National River in 2002, in concentrations exceeding those thought likely to cause adverse effects to wildlife. Very low concentrations of bioavailable PAHs were measured in streams in and near the New River Gorge National River by the use of semipermeable membrane devices. The apparent contradiction between the high concentrations of total PAHs and the low concentrations of bioavailable PAHs may result from the presence of a substantial amount of particulate coal in bottom sediment.

Watershed-based sources of polycyclic aromatic hydrocarbons in urban storm water.

PubMed

Stein, Eric D; Tiefenthaler, Liesl L; Schiff, Kenneth

2006-02-01

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 characterized the sources and temporal patterns of PAHs in urban storm water by analyzing PAH concentrations and loads from a range of homogeneous land use sites and in-river mass emission sites throughout the greater Los Angeles, California, USA, region. Samples were collected at 30- to 60-min intervals over the course of a storm during multiple storm events over a four-year period in order to investigate PAH sources and inter- and intrastorm patterns in loading. Polycyclic aromatic hydrocarbon storm fluxes ranged from 1.3 g/km2 for the largely undeveloped Arroyo Sequit watershed to 223.7 g/km2 for the highly urbanized Verdugo Wash watershed, with average storm fluxes being 46 times higher in developed versus undeveloped watersheds. Early-season storms repeatedly produced substantially higher loads than comparably sized late-season storms. Within individual storms, PAHs exhibited a moderate first flush with between 30 and 60% of the total PAH load being discharged in the first 20% of the storm volume. The relative distribution of individual PAHs demonstrated a consistent predominance of high-molecular-weight compounds indicative of pyrogenic sources.

Quasi-targeted analysis of hydroxylation-related metabolites of polycyclic aromatic hydrocarbons in human urine by liquid chromatography-mass spectrometry.

PubMed

Tang, Caiming; Tan, Jianhua; Fan, Ruifang; Zhao, Bo; Tang, Caixing; Ou, Weihui; Jin, Jiabin; Peng, Xianzhi

2016-08-26

Metabolite identification is crucial for revealing metabolic pathways and comprehensive potential toxicities of polycyclic aromatic hydrocarbons (PAHs) in human body. In this work, a quasi-targeted analysis strategy was proposed for metabolite identification of monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in human urine using liquid chromatography triple quadruple mass spectrometry (LC-QqQ-MS/MS) combined with liquid chromatography high resolution mass spectrometry (LC-HRMS). Potential metabolites of OH-PAHs were preliminarily screened out by LC-QqQ-MS/MS in association with filtering in a self-constructed information list of possible metabolites, followed by further identification and confirmation with LC-HRMS. The developed method can provide more reliable and systematic results compared with traditional untargeted analysis using LC-HRMS. In addition, data processing for LC-HRMS analysis were greatly simplified. This quasi-targeted analysis method was successfully applied to identifying phase I and phase II metabolites of OH-PAHs in human urine. Five metabolites of hydroxynaphthalene, seven of hydroxyfluorene, four of hydroxyphenanthrene, and three of hydroxypyrene were tentatively identified. Metabolic pathways of PAHs in human body were putatively revealed based on the identified metabolites. The experimental results will be valuable for investigating the metabolic processes of PAHs in human body, and the quasi-targeted analysis strategy can be expanded to the metabolite identification and profiling of other compounds in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

Plasma asymmetric dimethylarginine (ADMA) levels in Mexican women exposed to polycyclic aromatic hydrocarbons (PAHs): A preliminary study.

PubMed

Pruneda-Alvarez, Lucía G; Ruíz-Vera, Tania; Ochoa-Martínez, Angeles C; Pérez-Vázquez, Francisco J; González Palomo, Ana K; Ilizaliturri-Hernández, Cesar A; Pérez-Maldonado, Iván N

2016-12-01

Recent studies indicate that exposure to environmental pollutants (as polycyclic aromatic hydrocarbons) is a very important risk factor for development of cardiovascular diseases (CVDs). Correspondingly, in recent times asymmetric dimethylarginine (ADMA) has been proposed as a new and meaningful biomarker predictor for the risk of CVDs. Therefore, the objective of this study was to evaluate plasma ADMA concentrations in Mexican women (n=155) exposed to polycyclic aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene [(1-OHP), exposure biomarker for PAHs] levels were quantified using a high performance liquid chromatography (HPLC) technique and plasma ADMA concentrations were analyzed using a commercially available ELISA kit. Urinary 1-OHP levels in all women assessed ranged from

Metal-organic framework based in-syringe solid-phase extraction for the on-site sampling of polycyclic aromatic hydrocarbons from environmental water samples.

PubMed

Zhang, Xiaoqiong; Wang, Peiyi; Han, Qiang; Li, Hengzhen; Wang, Tong; Ding, Mingyu

2018-04-01

In-syringe solid-phase extraction is a promising sample pretreatment method for the on-site sampling of water samples because of its outstanding advantages of portability, simple operation, short extraction time, and low cost. In this work, a novel in-syringe solid-phase extraction device using metal-organic frameworks as the adsorbent was fabricated for the on-site sampling of polycyclic aromatic hydrocarbons from environmental waters. Trace polycyclic aromatic hydrocarbons were effectively extracted through the self-made device followed by gas chromatography with mass spectrometry analysis. Owing to the excellent adsorption performance of metal-organic frameworks, the analytes could be completely adsorbed during one adsorption cycle, thus effectively shortening the extraction time. Moreover, the adsorbed analytes could remain stable on the device for at least 7 days, revealing the potential of the self-made device for on-site sampling of degradable compounds in remote regions. The limit of detection ranged from 0.20 to 1.9 ng/L under the optimum conditions. Satisfactory recoveries varying from 84.4 to 104.5% and relative standard deviations below 9.7% were obtained in real samples analysis. The results of this study promote the application of metal-organic frameworks in sample preparation and demonstrate the great potential of in-syringe solid-phase extraction for the on-site sampling of trace contaminants in environmental waters. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impact of using fishing boat fuel with high poly aromatic content on the emission of polycyclic aromatic hydrocarbons from the diesel engine

NASA Astrophysics Data System (ADS)

Lin, Yuan-Chung; Lee, Wen-Jhy; Li, Hsing-Wang; Chen, Chung-Ban; Fang, Guor-Cheng; Tsai, Perng-Jy

Because of the fishery subsidy policy, the fishing boat fuel oil (FBFO) exemption from commodity taxes, business taxes and air pollution control fees, resulted in the price of FBFO was ˜50% lower than premium diesel fuel (PDF) in Taiwan. It is estimated that ˜650,000 kL FBFO was illegally used by traveling diesel-vehicles (TDVs) with a heavy-duty diesel engine (HDDE), which accounted for ˜16.3% of the total diesel fuel consumed by TDVs. In this study, sulfur, poly aromatic and total-aromatic contents in both FBFO and PDF were measured and compared. Exhaust emissions of polycyclic aromatic hydrocarbons (PAHs) and their carcinogenic potencies (BaP eq) from a HDDE under transient cycle testing for both FBFO and PDF were compared and discussed. Finally, the impact caused by the illegal use of FBFO on the air quality was examined. Results show that the mean sulfur-, poly aromatic and aromatic-contents in FBFO were 43.0, 3.89 and 1.04 times higher than that of PDF, respectively. Emission factors of total-PAHs and total-BaP eq obtained by utilizing FBFO were 51.5 and 0.235 mg L -1-Fuel, which were 3.41 and 5.82 times in magnitude higher than obtained by PDF, respectively. The estimated annual emissions of total-PAHs and total-BaP eq to the ambient environment due to the illegally used FBFO were 23.6 and 0.126 metric tons, respectively, which resulted in a 17.9% and a 25.0% increment of annual emissions from all mobile sources, respectively. These results indicated that the FBFO used illegally by TDVs had a significant impact on PAH emissions to the ambient environment.

Normal-phase liquid chromatography retention behavior of polycyclic aromatic hydrocarbon and their methyl-substituted derivatives on an aminopropyl stationary phase.

PubMed

Wilson, Walter B; Hayes, Hugh V; Sander, Lane C; Campiglia, Andres D; Wise, Stephen A

2017-09-01

Retention indices for 124 polycyclic aromatic hydrocarbons (PAHs) and 62 methyl-substituted (Me-) PAHs were determined using normal-phase liquid chromatography (NPLC) on a aminopropyl (NH 2 ) stationary phase. PAH retention behavior on the NH 2 phase is correlated to the total number of aromatic carbons in the PAH structure. Within an isomer group, non-planar isomers generally elute earlier than planar isomers. MePAHs generally elute slightly later but in the same region as the parent PAHs. Correlations between PAH retention behavior on the NH 2 phase and PAH thickness (T) values were investigated to determine the influence of non-planarity for isomeric PAHs with four to seven aromatic rings. Correlation coefficients ranged from r = 0.19 (five-ring peri-condensed molecular mass (MM) 252 Da) to r = -0.99 (five-ring cata-condensed MM 278 Da). In the case of the smaller PAHs (MM ≤ 252 Da), most of the PAHs had a planar structure and provided a low correlation. In the case of larger PAHs (MM ≥ 278 Da), nonplanarity had a significant influence on the retention behavior and good correlation between retention and T was obtained for the MM 278 Da, MM 302 Da, MM 328 Da, and MM 378 Da isomer sets. Graphical abstract NPLC separation of the three-, four-, five-, and six-ring PAH isomers with different number of aromatic carbon atoms and degrees of non-planarity (Thickness, T). The inserted figure plots the number of aromatic carbon atoms vs. the log I value for the 124 parent PAHs.

Evaluating porewater polycyclic aromatic hydrocarbon-related toxicity at a contaminated sediment site using a spiked field-sediment approach.

PubMed

Hartzell, Sharon E; Unger, Michael A; Vadas, George G; Yonkos, Lance T

2018-03-01

Although the complexity of contaminant mixtures in sediments can confound the identification of causative agents of adverse biological response, understanding the contaminant(s) of primary concern at impacted sites is critical to sound environmental management and remediation. In the present study, a stock mixture of 18 polycyclic aromatic hydrocarbon (PAH) compounds was prepared to reflect the variety and relative proportions of PAHs measured in surface sediment samples collected from discrete areas of a historically contaminated industrial estuary. This site-specific PAH stock mixture was spiked into nontoxic in-system and out-of-system field-collected reference sediments in dilution series spanning the range of previously measured total PAH concentrations from the region. Spiked sediments were evaluated in 10-d Leptocheirus plumulosus tests to determine whether toxicity in laboratory-created PAH concentrations was similar to the toxicity found in field-collected samples with equivalent PAH concentrations. The results show that toxicity of contaminated sediments was not explained by PAH exposure, while indicating that toxicity in spiked in-system (fine grain, high total organic carbon [TOC]) and out-of-system (course grain, low TOC) sediments was better explained by porewater PAH concentrations, measured using an antibody-based biosensor that quantified 3- to 5-ring PAHs, than total sediment PAH concentrations. The study demonstrates the application of site-specific spiking experiments to evaluate sediment toxicity at sites with complex mixtures of multiple contaminant classes and the utility of the PAH biosensor for rapid sediment-independent porewater PAH analysis. Environ Toxicol Chem 2018;37:893-902. © 2017 SETAC. © 2017 SETAC.

Hydrogenation of polycyclic aromatic hydrocarbons as a factor affecting the cosmic 6.2 micron emission band

NASA Technical Reports Server (NTRS)

Beegle, L. W.; Wdowiak, T. J.; Harrison, J. G.

2001-01-01

While many of the characteristics of the cosmic unidentified infrared (UIR) emission bands observed for interstellar and circumstellar sources within the Milky Way and other galaxies, can be best attributed to vibrational modes of the variants of the molecular family known as polycyclic aromatic hydrocarbons (PAH), there are open questions that need to be resolved. Among them is the observed strength of the 6.2 micron (1600 cm(-1)) band relative to other strong bands, and the generally low strength for measurements in the laboratory of the 1600 cm(-1) skeletal vibration band of many specific neutral PAH molecules. Also, experiments involving laser excitation of some gas phase neutral PAH species while producing long lifetime state emission in the 3.3 micron (3000 cm(-1)) spectral region, do not result in significant 6.2 micron (1600 cm(-1)) emission. A potentially important variant of the neutral PAH species, namely hydrogenated-PAH (H(N)-PAH) which exhibit intriguing spectral correlation with interstellar and circumstellar infrared emission and the 2175 A extinction feature, may be a factor affecting the strength of 6.2 micron emission. These species are hybrids of aromatic and cycloalkane structures. Laboratory infrared absorption spectroscopy augmented by density function theory (DFT) computations of selected partially hydrogenated-PAH molecules, demonstrates enhanced 6.2 micron (1600 cm(-1)) region skeletal vibration mode strength for these molecules relative to the normal PAH form. This along with other factors such as ionization or the incorporation of nitrogen or oxygen atoms could be a reason for the strength of the cosmic 6.2 micron (1600 cm(-1)) feature.

Photochemistry of Polycyclic Aromatic Hydrocarbons in Cosmic Water Ice: The Role of PAH Ionization and Concentration

NASA Astrophysics Data System (ADS)

Cook, Amanda M.; Ricca, Alessandra; Mattioda, Andrew L.; Bouwman, Jordy; Roser, Joseph; Linnartz, Harold; Bregman, Jonathan; Allamandola, Louis J.

2015-01-01

Infrared spectroscopic studies of ultraviolet (UV) irradiated, water-rich, cosmic ice analogs containing small polycyclic aromatic hydrocarbons (PAHs) are described. The irradiation studies of anthracene:H2O, pyrene:H2O, and benzo[ghi]perylene:H2O ices (14 K) at various concentrations reported by Bouwman et al. are extended. While aromatic alcohols and ketones have been reported in residues after irradiated PAH:H2O ices were warmed to 270 K, it was not known if they formed during ice irradiation or during warm-up when reactants interact as H2O sublimes. Recent work has shown that they form in low temperature ice. Using DFT computed IR spectra to identify photoproducts and PAH cations, we tentatively identify the production of specific alcohols [PAH(OH) n ] and quinones [PAH(O) n ] for all PAH:H2O ices considered here. Little evidence is found for hydrogenation at 14 K, consistent with the findings of Gudipati & Yang. Addition of O and OH to the parent PAH is the dominant photochemical reaction, but PAH erosion to smaller PAHs (producing CO2 and H2CO) is also important. DFT spectra are used to assess the contribution of PAH-related species to interstellar absorption features from 5 to 9 μm. The case is made that PAH cations are important contributors to the C2 component and PAH(OH) n and PAH(O) n to the C5 component described by Boogert et al. Thus, interstellar ices should contain neutral and ionized PAHs, alcohols, ketones and quinones at the ~2%-4% level relative to H2O. PAHs, their photoproducts, and ion-mediated processes should therefore be considered when modeling interstellar ice processes.

Availability of polycyclic aromatic hydrocarbons from lampblack-impacted soils at former oil-gas plant sites in California, USA.

PubMed

Hong, Lei; Luthy, Richard G

2007-03-01

Lampblack-impacted soils at former oil-gas plant sites in California, USA, were characterized to assess the sorption of polycyclic aromatic hydrocarbons (PAHs) and the concentration-dependent effects of a residual oil tar phase on sorption mechanism and availability of PAHs. Nuclear magnetic resonance spectroscopy demonstrated similar aromaticity for both lampblack carbon and the oil tar phase, with pronounced resonance signals in the range of 100 to 150 ppm. Scanning-electron microscopic images revealed a physically distinct oil tar phase, especially at high concentrations in lampblack, which resulted in an organic-like film structure when lampblack particles became saturated with the oil tar. Sorption experiments were conducted on a series of laboratory-prepared lampblack samples to systematically evaluate influences of an oil tar phase on PAH sorption to lampblack. Results indicate that the sorption of PAHs to lampblack exhibits a competition among sorption phases at low oil tar contents when micro- and mesopores are accessible. When the oil tar content increases to more than 5 to 10% by weight, this tar phase fills small pores, reduces surface area, and dominates PAH sorption on lampblack surface. A new PAH partitioning model, Kd = KLB-C(1 - ftar)alpha + ftarKtar (alpha = empirical exponent), incorporates these effects in which the control of PAH partitioning transits from being dominated by sorption in lampblack (KLB-C) to absorption in oil tar (Ktar), depending on the fraction of tar (ftar). This study illustrates the importance of understanding interactions among PAHs, oil tar, and lampblack for explaining the differences in availability of PAHs among site soils and, consequently, for refining site-specific risk assessment and establishing soil cleanup levels.

Lab Analysis of Dust Wipe Samples

EPA Pesticide Factsheets

Dust wipe samples collected on residential properties near the fenceline of KCBX North and South Terminals in Chicago, which store and handle pet coke, were analyzed for polycyclic aromatic hydrocarbons (PAHs) and trace metals and minerals.

ENGINEERING BULLETIN: COMPOSTING

EPA Science Inventory

Composting is an emerging ex situ biological technology that is potentially applicable to nonvolatile and semivolatile organic compounds (SVOCs) in soils. It has been applied to polycyclic aromatic hydrocarbons (PAHs) and explosives. It has been found to be potentially effectiv...

A Sandwich ELISA for Adducts of Polycyclic Aromatic Hydrocarbons with Human Serum Albumin1

PubMed Central

Chung, Ming Kei; Riby, Jacques; Li, He; Iavarone, Anthony T.; Williams, Evan R.; Zheng, Yuxin; Rappaport, Stephen M.

2010-01-01

Adducts of benzo[α]pyrene-diolepoxide (BPDE)2 with blood nucleophiles have been used as biomarkers of exposure to polycyclic aromatic hydrocarbons (PAHs). The most popular such assay is a competitive ELISA which employs monoclonal antibody 8E11 to detect benzo[α]pyrene tetrols following hydrolysis of BPDE adducts from lymphocyte DNA or human serum albumin (HSA). Here we use 8E11 as the capture antibody in a sandwich ELISA to detect BPDE-HSA adducts directly in 1 mg samples of HSA or 20 μL of serum/plasma. The assay employs an anti-HSA antibody for detection, which is amplified by an avidin/biotinylated horseradish peroxidase complex. The sandwich ELISA has advantages of specificity and simplicity and is about 10 times more sensitive than the competitive ELISA. To validate the assay, HSA samples were assayed from three populations with known high (coke-oven workers), medium (steel-factory control workers), and low (volunteer subjects) PAH exposures (n = 30). The respective geometric mean levels of BPDE-HSA adducts, i.e., 67.8, 14.7 and 1.93 ng/mg HSA (1,010, 220 and 28.9 fmol BPDE equivalents/mg HSA), were significantly different (p < 0.05). The sandwich ELISA will be useful for screening PAH exposures in large epidemiologic studies and can be extended to other adducts for which capture antibodies are available. PMID:20083082

Evaluation of polycyclic aromatic hydrocarbon-DNA adducts in exfoliated oral cells by an immunohistochemical assay.

PubMed

Romano, G; Sgambato, A; Boninsegna, A; Flamini, G; Curigliano, G; Yang, Q; La Gioia, V; Signorelli, C; Ferro, A; Capelli, G; Santella, R M; Cittadini, A

1999-01-01

Polycyclic aromatic hydrocarbon-DNA adducts were evaluated in oral cells from 98 healthy volunteers by an immunohistochemical method using a specific antiserum against benzo(a)pyrene-DNA adducts revealed by the immunoperoxidase reaction. Mean adduct content, determined as relative staining intensity by absorbance image analyzer, was significantly higher in the cells from tobacco smokers compared with nonsmokers (330 +/- 98, n = 33 versus 286 +/- 83, n = 64, respectively) with a P = 0.013 obtained by two-sample t test with equal variances. We found that in the smoker group, the PAH-DNA adduct content increases with the number of cigarettes. Thus, the relative staining intensity was 305 +/- 105 in the group smoking 1-10 cigarettes/day (n = 16), 347 +/- 77 in the 11-20 group (n = 14), and 386 +/- 112 in the group smoking more than 20 cigarettes/day (n = 3; P = 0.03 by nonparametric test for trend). No significant association was detected between PAH-DNA adducts in oral cells and variables such as residential area, oral infections, alcohol or vitamin intake, grilled food consumption, and professional activity. This work confirms and extends previous data suggesting that this immunohistochemical method might be used as a valuable dosimeter of genotoxic damage in a carcinogen-exposed population, although further studies are needed to verify the applicability of the test in high-risk populations other than smokers.

Effective Enrichment and Detection of Trace Polycyclic Aromatic Hydrocarbons in Food Samples based on Magnetic Covalent Organic Framework Hybrid Microspheres.

PubMed

Li, Ning; Wu, Di; Hu, Na; Fan, Guangsen; Li, Xiuting; Sun, Jing; Chen, Xuefeng; Suo, Yourui; Li, Guoliang; Wu, Yongning

2018-04-04

The present study reported a facile, sensitive, and efficient method for enrichment and determination of trace polycyclic aromatic hydrocarbons (PAHs) in food samples by employing new core-shell nanostructure magnetic covalent organic framework hybrid microspheres (Fe 3 O 4 @COF-(TpBD)) as the sorbent followed by HPLC-DAD. Under mild synthetic conditions, the Fe 3 O 4 @COF-(TpBD) were prepared with the retention of colloidal nanosize, larger specific surface area, higher porosity, uniform morphology, and supermagnetism. The as-prepared materials showed an excellent adsorption ability for PAHs, and the enrichment efficiency of the Fe 3 O 4 @COF-(TpBD) could reach 99.95%. The obtained materials also had fast adsorption kinetics and realized adsorption equilibrium within 12 min. The eluent was further analyzed by HPLC-DAD, and good linearity was observed in the range of 1-100 ng/mL with the linear correlation being above 0.9990. The limits of detection (S/N = 3) and limits of quantitation (S/N = 10) for 15 PAHs were in the range of 0.83-11.7 ng/L and 2.76-39.0 ng/L, respectively. For the application, the obtained materials were employed for the enrichment of trace PAHs in food samples and exhibited superior enrichment capacity and excellent applicability.

Diversity of ndo Genes in Mangrove Sediments Exposed to Different Sources of Polycyclic Aromatic Hydrocarbon Pollution▿

PubMed Central

Gomes, Newton C. Marcial; Borges, Ludmila R.; Paranhos, Rodolfo; Pinto, Fernando N.; Krögerrecklenfort, Ellen; Mendonça-Hagler, Leda C. S.; Smalla, Kornelia

2007-01-01

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 had characteristic compositions and levels of PAH compounds in the sediments were selected. The diversity and relative abundance of ndo genes in total community DNA were assessed by a newly developed ndo denaturing gradient gel electrophoresis (DGGE) approach and by PCR amplification with primers targeting ndo genes with subsequent Southern blot hybridization analyses. Bacterial populations inhabiting sediments of urban mangroves under the impact of different sources of PAH contamination harbor distinct ndo genotypes. Sequencing of cloned ndo amplicons comigrating with dominant DGGE bands revealed new ndo genotypes. PCR-Southern blot analysis and ndo DGGE showed that the frequently studied nah and phn genotypes were not detected as dominant ndo types in the mangrove sediments. However, ndo genotypes related to nagAc-like genes were detected, but only in oil-contaminated mangrove sediments. The long-term impact of PAH contamination, together with the specific environmental conditions at each site, may have affected the abundance and diversity of ndo genes in sediments of urban mangroves. PMID:17905873

Nanofiller Presence Enhances Polycyclic Aromatic Hydrocarbon (PAH) Profile on Nanoparticles Released during Thermal Decomposition of Nano-enabled Thermoplastics: Potential Environmental Health Implications.

PubMed

Singh, Dilpreet; Schifman, Laura Arabella; Watson-Wright, Christa; Sotiriou, Georgios A; Oyanedel-Craver, Vinka; Wohlleben, Wendel; Demokritou, Philip

2017-05-02

Nano-enabled products are ultimately destined to reach end-of-life with an important fraction undergoing thermal degradation through waste incineration or accidental fires. Although previous studies have investigated the physicochemical properties of released lifecycle particulate matter (called LCPM) from thermal decomposition of nano-enabled thermoplastics, critical questions about the effect of nanofiller on the chemical composition of LCPM still persist. Here, we investigate the potential nanofiller effects on the profiles of 16 Environmental Protection Agency (EPA)-priority polycyclic aromatic hydrocarbons (PAHs) adsorbed on LCPM from thermal decomposition of nano-enabled thermoplastics. We found that nanofiller presence in thermoplastics significantly enhances not only the total PAH concentration in LCPM but most importantly also the high molecular weight (HMW, 4-6 ring) PAHs that are considerably more toxic than the low molecular weight (LMW, 2-3 ring) PAHs. This nano-specific effect was also confirmed during in vitro cellular toxicological evaluation of LCPM for the case of polyurethane thermoplastic enabled with carbon nanotubes (PU-CNT). LCPM from PU-CNT shows significantly higher cytotoxicity compared to PU which could be attributed to its higher HMW PAH concentration. These findings are crucial and make the case that nanofiller presence in thermoplastics can significantly affect the physicochemical and toxicological properties of LCPM released during thermal decomposition.

Polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs and related environmental compounds: biological markers of exposure and effects.

PubMed Central

Talaska, G; Underwood, P; Maier, A; Lewtas, J; Rothman, N; Jaeger, M

1996-01-01

Lung cancer caused by polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs and related environmental agents is a major problem in industrialized nations. The high case-fatality rate of the disease, even with the best supportive treatment, underscores the importance of primary lung cancer prevention. Development of biomarkers of exposure and effects to PAHs and related compounds is now underway and includes measurement of urinary metabolites of specific PAHs as well as detection of protein and DNA adducts as indicators of effective dose. Validation of these markers in terms of total environmental dose requires that concurrent measures of air levels and potential dermal exposure be made. In addition, the interrelationships between PAH biomarkers must be determined, particularly when levels of the marker in surrogate molecules (e.g., protein) or markers from surrogate tissues (e.g., lymphocyte DNA) are used to assess the risk to the target organ, the lung. Two approaches to biomarker studies will be reviewed in this article: the progress made using blood lymphocytes as surrogates for lung tissues and the progress made developing noninvasive markers of carcinogen-DNA adduct levels in lung-derived cells available in bronchial-alveolar lavage and in sputum. Data are presented from studies in which exfoliated urothelial cells were used as a surrogate tissue to assess exposure to human urinary bladder carcinogens in occupational groups. PMID:8933032

Long-term PAH monitoring results from the Anacostia River active capping demonstration using polydimethylsiloxane (PDMS) fibers.

PubMed

Lampert, David J; Lu, Xiaoxia; Reible, Danny D

2013-03-01

In this paper, the long-term monitoring results for hydrophobic organic compounds, specifically polycyclic aromatic hydrocarbons (PAHs), from a field demonstration of capping contaminated sediments at the Anacostia River in Washington DC are presented and analyzed. In situ pore water concentrations in field-contaminated sediments in the demonstration caps were quantified using a polydimethylsiloxane (PDMS)-based passive sampling device. High resolution vertical pore water concentration profiles were measured using the device and were used to infer fate and transport of polycyclic aromatics hydrocarbons (PAHs) at the site. The derived pore water concentrations were compared with observed bioaccumulation and solid-phase concentration profiles to infer contaminant migration rates and mechanisms. Observed pore water concentrations were found to be a better predictor of bioaccumulation than solid-phase concentrations. Solid-phase concentrations were low in cores which implied containment of contamination; however pore water profiles showed that contaminant migration had occurred in the first few years after cap placement. The discrepancy is the result of the low sorption capacity of the sand. Because of surface re-contamination, low sorption capacity in the demonstration caps and strong tidal pumping effects, steady state contaminant profiles were reached in the caps several years after placement. Despite re-contamination at the surface, steady state concentrations in the capped areas showed decreased contamination levels relative to the control area.

Distribution of polycyclic aromatic hydrocarbons in the food web of a high mountain lake, Pyrenees, Catalonia, Spain.

PubMed

Vives, Ingrid; Grimalt, Joan O; Ventura, Marc; Catalan, Jordi

2005-06-01

We investigated the contents of polycyclic aromatic hydrocarbons (PAHs) in the food web organisms included in the diet of brown trout from a remote mountain lake. The preferential habitat and trophic level of the component species have been assessed from the signature of stable isotopes (delta13C and delta15N). Subsequently, the patterns of accumulation and transformation of these hydrocarbons in the food chain have been elucidated. Most of the food web organisms exhibit PAH distributions largely dominated by phenanthrene, which agrees with its predominance in atmospheric deposition, water, and suspended particles. Total PAH levels are higher in the organisms from the littoral habitat than from the deep sediments or the pelagic water column. However, organisms from deep sediments exhibit higher proportions of higher molecular weight PAH than those in other lake areas. Distinct organisms exhibit specific features in their relative PAH composition that point to different capacities for uptake and metabolic degradation. Brown trout show an elevated capacity for metabolic degradation because they have lower PAH concentrations than food and they are enriched strongly in lower molecular weight compounds. The PAH levels in trout highly depend on organisms living in the littoral areas. Fish exposure to PAH, therefore, may vary from lake to lake according to the relative contribution of littoral organisms to their diet.

Health risk assessment of polycyclic aromatic hydrocarbons in the source water and drinking water of China: Quantitative analysis based on published monitoring data.

PubMed

Wu, Bing; Zhang, Yan; Zhang, Xu-Xiang; Cheng, Shu-Pei

2011-12-01

A carcinogenic risk assessment of polycyclic aromatic hydrocarbons (PAHs) in source water and drinking water of China was conducted using probabilistic techniques from a national perspective. The published monitoring data of PAHs were gathered and converted into BaP equivalent (BaP(eq)) concentrations. Based on the transformed data, comprehensive risk assessment was performed by considering different age groups and exposure pathways. Monte Carlo simulation and sensitivity analysis were applied to quantify uncertainties of risk estimation. The risk analysis indicated that, the risk values for children and teens were lower than the accepted value (1.00E-05), indicating no significant carcinogenic risk. The probability of risk values above 1.00E-05 was 5.8% and 6.7% for adults and lifetime groups, respectively. Overall, carcinogenic risks of PAHs in source water and drinking water of China were mostly accepted. However, specific regions, such as Yellow river of Lanzhou reach and Qiantang river should be paid more attention. Notwithstanding the uncertainties inherent in the risk assessment, this study is the first attempt to provide information on carcinogenic risk of PAHs in source water and drinking water of China, and might be useful for potential strategies of carcinogenic risk management and reduction. Copyright © 2011 Elsevier B.V. All rights reserved.

A metabolomics strategy to assess the combined toxicity of polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs).

PubMed

Wang, Feidi; Zhang, Haijun; Geng, Ningbo; Ren, Xiaoqian; Zhang, Baoqin; Gong, Yufeng; Chen, Jiping

2018-03-01

The combined toxicity of mixed chemicals is usually evaluated according to several specific endpoints, and other potentially toxic effects are disregarded. In this study, we provided a metabolomics strategy to achieve a comprehensive understanding of toxicological interactions between mixed chemicals on metabolism. The metabolic changes were quantified by a pseudotargeted analysis, and the types of combined effects were quantitatively discriminated according to the calculation of metabolic effect level index (MELI). The metabolomics strategy was used to assess the combined effects of polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs) on the metabolism of human hepatoma HepG2 cells. Our data suggested that exposure to a combination of PAHs and SCCPs at human internal exposure levels could result in an additive effect on the overall metabolism, whereas diverse joint effects were observed on various metabolic pathways. The combined exposure could induce a synergistic up-regulation of phospholipid metabolism, an additive up-regulation of fatty acid metabolism, an additive down-regulation of tricarboxylic acid cycle and glycolysis, and an antagonistic effect on purine metabolism. SCCPs in the mixture acted as the primary driver for the acceleration of phospholipid and fatty acid metabolism. Lipid metabolism disorder caused by exposure to a combination of PAHs and SCCPs should be an important concern for human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhancement of polycyclic aromatic hydrocarbons in estuarine invertebrates by surface runoff at a decommissioned military fuel depot

USGS Publications Warehouse

Miles, A.K.; Roster, N.

1999-01-01

Accumulation of polycyclic aromatic hydrocarbons (PAHs) was determined in blue mussels (Mytilus spp.) and shore crabs (Hemigrapsus sp.) at a recently closed military fuel depot in central San Francisco Bay, California. In April 1996, during a period of above average precipitation, specimens were collected at the depot, near the depot, and at sites 10 and 20 km south of the depot. Four weeks after the rains ended, blue mussels were again collected at the depot, and at two additional sites in the central Bay region. In April, total PAHs in mussels from the depot were significantly higher only than that in mussels collected 20 km from the depot; however, seven specific, substituted PAHs were higher at the depot than at all other sites. In June, only two of the 38 PAHs common in mussels in April were detected at the depot; these concentrations were comparable to ambient concentrations in mussels at the Bay. It seemed that bioavailability of PAHs at the depot was enhanced by rainfall, probably due to the mobilization of PAHs via groundwater into the Bay. Concentrations in mussels from chronically contaminated sites were about five times higher than mussels collected from the depot. Low PAH concentrations were detected in shore crabs near the depot, and the highest levels were not associated with the depot. Observed PAH concentrations are discussed in relation to upper trophic organisms.

Development of a screening tool to prioritize testing for the carcinogenic hazard of residual aromatic extracts and related petroleum streams.

PubMed

Goyak, Katy O; Kung, Ming H; Chen, Min; Aldous, Keith K; Freeman, James J

2016-12-15

Residual aromatic extracts (RAE) are petroleum substances with variable composition predominantly containing aromatic hydrocarbons with carbon numbers greater than C25. Because of the high boiling nature of RAEs, the aromatics present are high molecular weight, with most above the range of carcinogenic polycyclic aromatic hydrocarbons (PAHs). However, refinery distillations are imperfect; some PAHs and their heteroatom-containing analogs (collectively referred to as polycyclic aromatic content or PAC) may remain in the parent stream and be extracted into the RAE, and overall PAC content is related to the carcinogenic potential of an RAE. We describe here a real-time analytical chemistry-based tool to assess the carcinogenic hazard of RAE via the development of a functional relationship between carcinogenicity and boiling point. Samples representative of steps along the RAE manufacturing process were obtained from five refineries to evaluate relationships between mutagenicity index (MI), PAC ring content and gas chromatographic distillation (GCD) curves. As expected, a positive linear relationship between MI and PAC ring content occurred, most specifically for 3-6 ring PAC (R 2 =0.68). A negative correlation was found between MI and temperature at 5% vaporization by GCD (R 2 =0.72), indicating that samples with greater amounts of lower boiling constituents were more likely to be carcinogenic. The inverse relationship between boiling range and carcinogenicity was further demonstrated by fractionation of select RAE samples (MI=0.50+0.07; PAC=1.70+0.51wt%; n=5) into low and high boiling fractions, where lower boiling fractions were both more carcinogenic than the higher boiling fractions (MI=2.36±0.55 and 0.17±0.11, respectively) and enriched in 3-6 ring PACs (5.20+0.70wt% and 0.97+0.35wt%, respectively). The criteria defining carcinogenicity was established as 479°C for the 5% vaporization points by GCD, with an approximate 95% probability of a future sample having an MI below the recommended limit of 0.4 for RAEs. Overall, these results provide a cost-efficient and real-time tool by which the carcinogenic potential of RAEs can be assessed at the refinery level, ultimately providing a means to readily monitor and minimize the carcinogenic potential of RAEs. Copyright © 2016. Published by Elsevier Ireland Ltd.

CHEMISTRY OF OXIDATION OF POLYCYCLIC AROMATIC HYDROCARBONS BY SOIL PSEUDOMONADS

PubMed Central

Rogoff, Martin H.

1962-01-01

Rogoff, Martin H. (U.S. Bureau of Mines, Pittsburgh, Pa.). Oxidation of polycyclic aromatic hydrocarbons by soil pseudomonads. J. Bacteriol. 83:998–1004. 1962.—Substitution of phenanthrene by a methyl group at the 9-carbon blocks oxidation of the compound by a resting-cell suspension of a phenanthrene-grown soil pseudomonad. When 2-methylphenanthrene is provided, the oxidation rate is considerably higher; 3-methylphenanthrene is oxidized at a rate intermediate between the other two, even though the methyl group is attached to a carbon directly involved in ring splitting. Cells grown on naphthalene or anthracene oxidize phenanthrene at a much lower rate than cells grown with phenanthrene or 2-methylnaphthalene as the source of carbon. Naphthalene-grown cells also absorb less phenanthrene from aqueous solution than do their phenanthrene-grown counterparts. The data are in keeping with the hypothesis that polynuclear aromatic hydrocarbons attach to the relevant bacterial enzymes at carbon-carbon bonds of high electron density (K regions; localized double bonds), and that the ring-splitting reactions then occur at other bonds on the substrate molecule. The actual bond that undergoes fission is determined by the electronic and steric configurations of the enzyme-substrate complex. When linearly arranged aromatic compounds such as naphthalene or anthracene are attacked, attachment to an enzyme and ring splitting may take place on the same ring; angular aromatic compounds such as phenanthrene afford attachment to an enzyme at a bond in a ring other than the one containing the ring-splitting site. PMID:14493381

Gas-phase reactions of phenyl radicals with aromatic molecules

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

Fahr, A.; Stein, S.E.

1988-08-25

Relative rates of reactions of phenyl radicals with a series of aromatic and polycyclic aromatic compounds are reported. Most studies were done in static reactors at 450/degrees/C using diphenyl diketone (benzil) as the phenyl radical source. Reactions with the following molecules are reported: benzene, toluene, p-xylene, 1,3,5-trimethylbenzene, phenol, bromobenzene, naphthalene, biphenyl, anthracene, 9-methylanthracene, and triphenylene. For reactions with substituted benzenes, H abstraction is the dominant reaction. Relative rates of phenylation at different sites do not closely follow established trends for rates of radical attack. It is proposed that these deviations are primarily due to a dependence of the degree ofmore » reversibility on the specific site of phenylation. These studies also show that the rates of phenyl and H-atom migration around the ring in adduct radicals are slow relative to dissociation. Also, by use of these results to link literature rate data from high and low temperatures, a rate expression for H abstraction from p-xylene by phenyl of 10/sup 9.6/ exp(-4.4 kcal/RT) M/sup /minus/1/ s/sup /minus/1/ is derived.« less

Ab initio simulations of subatomic resolution images in noncontact atomic force microscopy

NASA Astrophysics Data System (ADS)

Kim, Minjung; Chelikowsky, James R.

2015-03-01

Direct imaging of polycyclic aromatic molecules with a subatomic resolution has recently been achieved with noncontact atomic force microscopy (nc-AFM). Specifically, nc-AFM employing a CO functionalized tip has provided details of the chemical bond in aromatic molecules, including the discrimination of bond order. However, the underlying physics of such high resolution imaging remains problematic. By employing new, efficient algorithms based on real space pseudopotentials, we calculate the forces between the nc-AFM tip and specimen. We simulate images of planar organic molecules with two different approaches: 1) with a chemically inert tip and 2) with a CO functionalized tip. We find dramatic differences in the resulting images, which are consistent with recent experimental work. Our work is supported by the DOE under DOE/DE-FG02-06ER46286 and by the Welch Foundation under Grant F-1837. Computational resources were provided by NERSC and XSEDE.

Three-dimensional aromatic networks.

PubMed

Toyota, Shinji; Iwanaga, Tetsuo

2014-01-01

Three-dimensional (3D) networks consisting of aromatic units and linkers are reviewed from various aspects. To understand principles for the construction of such compounds, we generalize the roles of building units, the synthetic approaches, and the classification of networks. As fundamental compounds, cyclophanes with large aromatic units and aromatic macrocycles with linear acetylene linkers are highlighted in terms of transannular interactions between aromatic units, conformational preference, and resolution of chiral derivatives. Polycyclic cage compounds are constructed from building units by linkages via covalent bonds, metal-coordination bonds, or hydrogen bonds. Large cage networks often include a wide range of guest species in their cavity to afford novel inclusion compounds. Topological isomers consisting of two or more macrocycles are formed by cyclization of preorganized species. Some complicated topological networks are constructed by self-assembly of simple building units.

Treatment of contaminated roadway runoff using vegetated filter strips.

DOT National Transportation Integrated Search

2009-01-01

The overall goal of this field study was to evaluate the potential effectiveness of vegetated highway embankments as a stormwater runoff best management practice (BMP) for retention of metals, polycyclic aromatic hydrocarbons (PAHs), and particulates...

IMPORTANCE OF ENZYMATIC BIOTRANSFORMATION IN IMMUNOTOXICOLOGY

EPA Science Inventory

Many immunotoxic compounds, such as benzene and other organic solvents, pesticides, mycotoxins and polycyclic aromatic hydrocarbons, can alter immune function only after undergoing enzyme-mediated reactions within various tissues. In the review that follows, the role of enzymatic...

SITE EMERGING TECHNOLOGY REPORT: INNOVATIVE METHODS FOR BIOSLURRY TREATMENT

EPA Science Inventory

IT Corporation (IT), Knoxville, Tennessee, in collaboration with U.S. Environmental protection Agency (EPA), investigated the feasibility of combined biological and chemical oxidation of polycyclic aromatic hydrocarbons (PAH). Bioslurry treatment of PAH-contaminated soils was dem...

21 CFR 74.2053 - D&C Black No. 3.

Code of Federal Regulations, 2010 CFR

2010-04-01

... may be avoided by current good manufacturing practices: (1) Calcium hydroxyapatite (CaO and P2O5), not...) Total polycyclic aromatic hydrocarbons (PAHs), not more than 5 mg/kg (5 ppm). (c) Uses and restrictions...

SOURCES OF HUMAN EXPOSURE TO AIRBORNE PAH

EPA Science Inventory

Personal exposures to airborne particulate polycyclic aromatic hydrocarbons (PAHs) were studied in several populations in the US, Japan, and Czech Republic. Personal exposure monitors, developed for human exposure biomonitoring studies were used to collect fine particles (<_ 1....

ACTIVATION OF OYSTER DEFENSES BY ENVIRONMENTAL CONTAMINANTS

EPA Science Inventory

Four field studies performed on eastern oysters Crassostrea virginica support a hypothesis that Cu, Zn, and perhaps butyltins and polycyclic aromatic hydrocarbons (PAH) can stimulate hemopoiesis, hemocyte locomotion and hemocyte bactericidal capacity. The first study found circul...

A Free-Radical Pathway to Hydrogenated Phenanthrene in Molecular Clouds-Low Temperature Growth of Polycyclic Aromatic Hydrocarbons.

PubMed

Thomas, Aaron M; Lucas, Michael; Yang, Tao; Kaiser, Ralf I; Fuentes, Luis; Belisario-Lara, Daniel; Mebel, Alexander M

2017-08-05

The hydrogen-abstraction/acetylene-addition mechanism has been fundamental to unravelling the synthesis of polycyclic aromatic hydrocarbons (PAHs) detected in combustion flames and carbonaceous meteorites like Orgueil and Murchison. However, the fundamental reaction pathways accounting for the synthesis of complex PAHs, such as the tricyclic anthracene and phenanthrene along with their dihydrogenated counterparts, remain elusive to date. By investigating the hitherto unknown chemistry of the 1-naphthyl radical with 1,3-butadiene, we reveal a facile barrierless synthesis of dihydrophenanthrene adaptable to low temperatures. These aryl-type radical additions to conjugated hydrocarbons via resonantly stabilized free-radical intermediates defy conventional wisdom that PAH growth is predominantly a high-temperature phenomenon and thus may represent an overlooked path to PAHs as complex as coronene and corannulene in cold regions of the interstellar medium like in the Taurus Molecular Cloud. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aliphatic and polycyclic aromatic hydrocarbons in Gulf of Trieste sediments (northern Adriatic): potential impacts of maritime traffic.

PubMed

Bajt, Oliver

2014-09-01

The Gulf of Trieste (northern Adriatic) is one of the most urbanized and industrialized areas in the northern Adriatic, with intense maritime traffic experienced at multiple ports. The impact of maritime traffic on contamination by hydrocarbons in this area was assessed. Concentrations of hydrocarbons were higher near the expected contamination sources and still elevated in the adjacent offshore areas. Aliphatic hydrocarbons were mainly of petrogenic origin, with some contribution of biogenic origin. A continuous contamination by aliphatic hydrocarbons and degradation processes were hypothesized. Concentrations of total polycyclic aromatic hydrocarbons (PAH) were generally greater near the contamination sources. Compared to the prevailing pyrolytic origin, the petrogenic PAH origin seemed to be less important, but not negligible. Results revealed that intensive maritime traffic is a probable source of contamination by hydrocarbons in the investigated area, which is largely limited to areas near the contamination sources.

Sources and pathways of polycyclic aromatic and saturated hydrocarbons in the Arkona Basin (Southern Baltic Sea, Central Europe)

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

Schulz, H.M.

The Baltic Sea (Central Europe) is surrounded by coastal regions with long histories of industrialization. The heavy metal profiles in the sediments in the center of the Arkona Basin, one of the depressions of the southern Baltic Sea area, clearly reflect the historical anthropogenic influence. The Arkona Basin-is the final sink for materials derived from the Oder river which drains a highly polluted industrial area of Eastern Europe. Surficial muddy sediments from a close-meshed field of sampling-points were analyzed for distribution patterns of aliphatics and quantities and ratios of selected polycyclic aromatic hydrocarbons (PAH). These compounds are thought to reflectmore » anthropogenic pollution related to emissions from traffic, heating, etc. We use these marker substances to test if the basin sediments reflect riverine input, and if additional sources can be identified.« less

Development and certification of a coal fly ash certified reference material for selected polycyclic aromatic hydrocarbons.

PubMed

Cao, X; Xu, X; Cui, W; Xi, Z

2001-08-01

The development and certification of a coal fly ash certified reference material (CRM) for polycyclic aromatic hydrocarbons (PAH) is described; this is the first natural matrix CRM for organic environmental analysis in China. The homogeneity and stability of this material have been tested by HPLC. The concentrations of several PAH were determined by use of two independent, different methods--solvent extraction-HPLC analysis with UV detection coupled with fluorescence detection (FLD) and solvent extraction, isolation with a silica column, and GC analysis with flame ionization detection (FID). Five certified values were determined: phenanthrene 7.1 +/- 2.6 microg g(-1), anthracene 2.0 +/- 0.8 microg g(-1), fluoranthene 7.4 +/- 1.9 microg g(-1), pyrene 7 +/- 2 microg g(-1), and benzo[a]pyrene 1.3 +/- 0.3 microg g(-1). Reference values for several other PAH are also suggested.

Polycyclic aromatic hydrocarbons and their molecular diagnostic ratios in urban atmospheric respirable particulate matter

NASA Astrophysics Data System (ADS)

del Rosario Sienra, María; Rosazza, Nelson G.; Préndez, Margarita

2005-06-01

Atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs) in Santiago de Chile city were evaluated to study particulate PAHs profiles during cold and spring weather periods. Urban atmospheric particulate matter PM10 was collected using High Volume PM10 samplers. Fifteen samples of 24 h during austral winter and 20 samples of 24 h during spring, 2000 were collected at two sampling sites (North-East and Central areas of the city) whose characteristics were representative of the prevailing conditions. Seventeen PAHs were quantified and total PAHs concentration ranged from 1.39 to 59.98 ng m -3, with a seasonal variation (winter vs. spring ratio) from 0.5 to 12.6 ng m -3. Molecular diagnostic ratios were used to characterize and identify PAHs emission sources such as combustion and biogenic emissions. Results showed that the major sources of respirable organic aerosol PM10 in Santiago are mobile and stationary ones.

Molecular Growth Inside of Polycyclic Aromatic Hydrocarbon Clusters Induced by Ion Collisions.

PubMed

Delaunay, Rudy; Gatchell, Michael; Rousseau, Patrick; Domaracka, Alicja; Maclot, Sylvain; Wang, Yang; Stockett, Mark H; Chen, Tao; Adoui, Lamri; Alcamí, Manuel; Martín, Fernando; Zettergren, Henning; Cederquist, Henrik; Huber, Bernd A

2015-05-07

The present work combines experimental and theoretical studies of the collision between keV ion projectiles and clusters of pyrene, one of the simplest polycyclic aromatic hydrocarbons (PAHs). Intracluster growth processes induced by ion collisions lead to the formation of a wide range of new molecules with masses larger than that of the pyrene molecule. The efficiency of these processes is found to strongly depend on the mass and velocity of the incoming projectile. Classical molecular dynamics simulations of the entire collision process-from the ion impact (nuclear scattering) to the formation of new molecular species-reproduce the essential features of the measured molecular growth process and also yield estimates of the related absolute cross sections. More elaborate density functional tight binding calculations yield the same growth products as the classical simulations. The present results could be relevant to understand the physical chemistry of the PAH-rich upper atmosphere of Saturn's moon Titan.

Bioremediation of soils contaminated with polycyclic aromatic hydrocarbons, petroleum, pesticides, chlorophenols and heavy metals by composting: Applications, microbes and future research needs.

PubMed

Chen, Ming; Xu, Piao; Zeng, Guangming; Yang, Chunping; Huang, Danlian; Zhang, Jiachao

2015-11-01

Increasing soil pollution problems have caused world-wide concerns. Large numbers of contaminants such as polycyclic aromatic hydrocarbons (PAHs), petroleum and related products, pesticides, chlorophenols and heavy metals enter the soil, posing a huge threat to human health and natural ecosystem. Chemical and physical technologies for soil remediation are either incompetent or too costly. Composting or compost addition can simultaneously increase soil organic matter content and soil fertility besides bioremediation, and thus is believed to be one of the most cost-effective methods for soil remediation. This paper reviews the application of composting/compost for soil bioremediation, and further provides a critical view on the effects of this technology on microbial aspects in contaminated soils. This review also discusses the future research needs for contaminated soils. Copyright © 2015 Elsevier Inc. All rights reserved.

Polycyclic aromatic hydrocarbons affect survival and development of common snapping turtle (Chelydra serpentina) embryos and hatchlings.

PubMed

Van Meter, Robin J; Spotila, James R; Avery, Harold W

2006-08-01

Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds found in the John Heinz National Wildlife Refuge in Philadelphia, Pennsylvania. We assessed the impact of PAHs and crude oil on snapping turtle development and behavior by exposing snapping turtle eggs from the Refuge and from three clean reference sites to individual PAHs or a crude oil mixture at stage 9 of embryonic development. Exposure to PAHs had a significant effect on survival rates in embryos from one clean reference site, but not in embryos from the other sites. There was a positive linear relationship between level of exposure to PAHs and severity of deformities in embryos collected from two of the clean reference sites. Neither righting response nor upper temperature tolerance (critical thermal maximum, CTM) of snapping turtle hatchlings with no or minor deformities was significantly affected by exposure to PAHs.

Polycyclic aromatic hydrocarbons (PAHs) in yogurt samples.

PubMed

Battisti, Chiara; Girelli, Anna Maria; Tarola, Anna Maria

2015-01-01

The concentrations and distributions of major polycyclic aromatic hydrocarbons (PAHs) were determined in 20 kinds of yogurt specimens collected from Italian supermarkets using reversed phase high-performance liquid chromatography equipped with fluorescence detection. The method was validated by determination of recovery percentages, precision (repeatability) and sensitivity (limits of detection) with yogurt samples fortified at 0.25, 0.5 and 1 µg/kg concentration levels. The recovery of 13 PAHs, with the exception of naphthalene and acenaphthene, ranged from 61% to 130% and from 60% to 97% at all the levels for yogurts with low (0.1%) and high (3.9%) fat content, respectively. The method is repeatable with relative standard deviation values <20% for all analytes. The results obtained demonstrate that acenaphthene, fluorantene, phenanthrene, anthracene, fluoranthene and pyrene were found in all samples with a similar distribution, but different content when yogurts with low and high fats were compared.

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

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

Barbara J. Mahler; Peter C. Van Metre; Thomas J. Bashara

2005-08-01

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 with coal-tar emulsion sealcoat had mean concentrations of PAHs of 3500 mg/kg, 65 times higher than the mean concentration from unsealed asphalt and cement lots. Diagnostic ratios of individual PAHs indicating sources are similar for particles from coal-tar emulsion sealedmore » lots and suspended sediment from four urban streams. Contaminant yields projected to the watershed scale for the four associated watersheds indicate that runoff from sealed parking lots could account for the majority of stream PAH loads. 35 refs., 6 figs., 2 tabs.« less

Study of nitro-polycyclic aromatic hydrocarbons in fine and coarse atmospheric particles

NASA Astrophysics Data System (ADS)

Teixeira, Elba Calesso; Garcia, Karine Oliveira; Meincke, Larissa; Leal, Karen Alam

2011-08-01

The purpose of the present study was to evaluate six nitro-polycyclic aromatic hydrocarbons (NPAHs) in fine (< 2.5 μm) and coarse (2.5-10 μm) atmospheric particles in an urban and industrial area located in the Metropolitan Area of Porto Alegre (MAPA), RS, Brazil. The method used was of NPAHs isolation and derivatization, and subsequent gas chromatography by electron capture detection (CG/ECD). Results revealed a higher concentration of NPAHs, especially 3-nitrofluoranthene and 1-nitropyrene, in fine particles in the sampling sites studied within the MAPA. The diagnostic ratios calculated for PAHs and NPAHs identified the influence of heavy traffic, mainly of diesel emissions. The correlation of NPAHs with other pollutants (NO x, NO 2, NO and O 3) evidence the influence of vehicular emissions in the MAPA. The seasonal variation evidenced higher NPAHs concentrations in the fine particles during winter for most compounds studied.

Chemical characterization of biomass fuel particulate deposits and ashes in households of Mt. Everest region (NEPAL).

PubMed

Ielpo, Pierina; Fermo, Paola; Comite, Valeria; Mastroianni, Domenico; Viviano, Gaetano; Salerno, Franco; Tartari, Gianni

2016-12-15

During a sampling campaign, carried out during June 2012, inside some traditional households located in four villages (Phakding, Namche, Pangboche and Tukla) of Mt. Everest region in southern part of the central Himalaya (Nepal), particulate matter (PM) depositions and ashes have been collected. Moreover, outdoor PM depositions have also been analyzed. Chemical characterization of PM depositions and ashes for major ions, organic carbon, elemental carbon (EC), metal content and PAHs (Polycyclic Aromatic Hydrocarbons) allowed identifying, as major contributes to indoor PM, the following sources: biomass burning, cooking and chimney ashes. These sources significantly affect outdoor PM depositions: in-house biomass burning is the major source for outdoor EC and K + as well as biomass burning and cooking activities are the major sources for Polycyclic Aromatic Hydrocarbons. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparative studies on lignin and polycyclic aromatic hydrocarbons degradation by basidiomycetes fungi.

PubMed

Arun, A; Eyini, M

2011-09-01

A total of 130 wild basidiomycetes fungi were collected and identified. The polycyclic aromatic hydrocarbons (PAHs) degradation by the potential Phellinus sp., Polyporus sulphureus (in liquid state fermentation (LSF), solid state fermentation (SSF), in soil) and lignin biodegradation were compared with those of a bacterial isolate and their corresponding cocultures. The PAHs degradation was higher in LSF and the efficiency of the organisms declined in SSF and in soil treatment. Phellinus sp. showed better degradation in SSF and in soil. Bacillus pumilus showed higher degradation in LSF. B. pumilus was seen to have lower lignin degradation than the fungal cultures and the cocultures could not enhance the degradation. Phellinus sp. which had higher PAHs and lignin degradation showed higher biosurfactant production than other organism. Manganese peroxidase (MnP) was the predominant enzyme in Phellinus sp. while lignin peroxidase (Lip) was predominant in P. sulphureus. Copyright © 2011 Elsevier Ltd. All rights reserved.

Integrating geophysical data for mapping the contamination of industrial sites by polycyclic aromatic hydrocarbons: A geostatistical approach

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

Colin, P.; Nicoletis, S.; Froidevaux, R.

1996-12-31

A case study is presented of building a map showing the probability that the concentration in polycyclic aromatic hydrocarbon (PAH) exceeds a critical threshold. This assessment is based on existing PAH sample data (direct information) and on an electrical resistivity survey (indirect information). Simulated annealing is used to build a model of the range of possible values for PAH concentrations and of the bivariate relationship between PAH concentrations and electrical resistivity. The geostatistical technique of simple indicator kriging is then used, together with the probabilistic model, to infer, at each node of a grid, the range of possible values whichmore » the PAH concentration can take. The risk map is then extracted for this characterization of the local uncertainty. The difference between this risk map and a traditional iso-concentration map is then discussed in terms of decision-making.« less

Polycyclic aromatic hydrocarbons - Primitive pigment systems in the prebiotic environment

NASA Technical Reports Server (NTRS)

Deamer, D. W.

1992-01-01

The chemical evolution of meteoritic organics in the primitive earth is examined experimentally with attention given to the photochemical effects of hydrocarbon/water mixtures. Also addressed are the generation of amphiphilic products by photochemical reactions and the transduction of light energy into potentially useful forms. Polycyclic aromatic hydrocarbons (PAHs) absorb light and exist in carbonaceous chondrites; PAHs are therefore examined as primitive pigments by means of salt solutions with pyrene, fluoranthene, and pyrene derivatives with hexadecane. The hexadecane undergoes photochemical oxidation and yields long-chain amphiphiles with oxygen supplied by water, and acid pH shifts also occur. PAHs are also tested in lipid bilayer membranes to examine light-energy transduction. Protons are found to accumulate within the membrane-bounded volume to form proton gradients, and this reaction is theorized to be a good model of primitive photochemical reactions that related to the transduction of light energy into useable forms.

Destruction and survival of polycyclic aromatic hydrocarbons in active galaxies

NASA Technical Reports Server (NTRS)

Voit, G. M.

1992-01-01

Infrared spectra of dusty galactic environments often contain emission features attributed to polycyclic aromatic hydrocarbons or PAHs, which can be considered to be very small grains or very large molecules. Although IR spectra of starburst galaxies almost always show these emission features, similar spectra of active galaxies are usually featureless. Even in those active galaxies that do exhibit PAH emission, the PAHs still appear to be eradicated from the nuclear region. This dichotomy suggests that PAHs are destroyed by the intense hard radiation field from an AGN. Laboratory experiments show that certain PAHs are, in fact, so effectively destroyed by individual EUV and X-ray photons that they cannot survive even at kiloparsec distances from active nuclei. Regions within active galaxies that do show PAH emission must therefore be shielded from the central X-ray source by a substantial column density of X-ray absorbing gas.

The influence of polycyclic aromatic hydrocarbons on lung function in a representative sample of the Canadian population.

PubMed

Cakmak, Sabit; Hebbern, Chris; Cakmak, Jasmine D; Dales, Robert E

2017-09-01

We investigated the associations between exposure to polycyclic aromatic hydrocarbons (PAHs) and selected respiratory physiologic measures in cycles 2 and 3 of the Canadian Health Measures Survey, a nationally representative population sample. Using generalized linear mixed models, we tested the association between selected PAH metabolites and 1-second forced expiratory volume (FEV 1 ), forced vital capacity (FVC), and the ratio between the two (FEV 1 /FVC) in 3531 people from 6 to 79 years of age. An interquartile change in urinary PAH metabolite was associated with significant decrements in FEV 1 and FVC for eight PAHs, 2-hydroxynapthalene, 1-, and 2-hydroxyphenanthrene, 2-, 3-, and 9-hydroxyfluorene and 3- and 4-hydroxyphenanthrene. Exposure to PAH may negatively affect lung function in the Canadian population. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

The discovery of a new infrared emission feature at 1905 wavenumbers (5.25 microns) in the spectrum of BD + 30 deg 3639 and its relation to the polycyclic aromatic hydrocarbon model

NASA Technical Reports Server (NTRS)

Allamandola, L. J.; Bregman, J. D.; Sandford, S. A.; Tielens, A. G. G. M.; Witteborn, F. C.

1989-01-01

A new IR emission feature at 1905/cm (5.25 microns) has been discovered in the spectrum of BD + 30 deg 3639. This feature joins the family of well-known IR emission features at 3040, 2940, 1750, 1610, '1310', 1160, and 890/cm. The origin of this new feature is discussed and it is assigned to an overtone or combination band involving C-H bending modes of polycyclic aromatic hydrocarbons (PAHs). Laboratory work suggests that spectral studies of the 2000-1650/cm region may be very useful in elucidating the molecular structure of interstellar PAHs. The new feature, in conjunction with other recently discovered spectral structures, suggests that the narrow IR emission features originate in PAH molecules rather than large carbon grains.

Polycyclic aromatic hydrocarbons in caribou, moose, and wolf scat samples from three areas of the Alberta oil sands.

PubMed

Lundin, Jessica I; Riffell, Jeffrey A; Wasser, Samuel K

2015-11-01

Impacts of toxic substances from oil production in the Alberta oil sands (AOS), such as polycyclic aromatic hydrocarbons (PAHs), have been widely debated. Studies have been largely restricted to exposures from surface mining in aquatic species. We measured PAHs in Woodland caribou (Rangifer tarandus caribou), moose (Alces americanus), and Grey wolf (Canis lupus) across three areas that varied in magnitude of in situ oil production. Our results suggest a distinction of PAH level and source profile (petro/pyrogenic) between study areas and species. Caribou samples indicated pyrogenic sourced PAHs in the study area previously devastated by forest fire. Moose and wolf samples from the high oil production area demonstrated PAH ratios indicative of a petrogenic source and increased PAHs, respectively. These findings emphasize the importance of broadening monitoring and research programs in the AOS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Polycyclic aromatic hydrocarbons (PAHs) in atmospheric dustfall from the industrial corridor in Hubei Province, Central China.

PubMed

Zhang, Jiaquan; Qu, Chengkai; Qi, Shihua; Cao, Junji; Zhan, Changlin; Xing, Xinli; Xiao, Yulun; Zheng, Jingru; Xiao, Wensheng

2015-10-01

Thirty atmospheric dustfall samples collected from an industrial corridor in Hubei Province, central China, were analyzed for 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) to investigate their concentrations, spatial distributions, sources, and health risks. Total PAH concentrations (ΣPAHs) ranged from 1.72 to 13.17 µg/g and averaged 4.91 µg/g. High molecular weight (4-5 rings) PAHs averaged 59.67% of the ΣPAHs. Individual PAH concentrations were not significantly correlated with total organic carbon, possibly due to the semi-continuous inputs from anthropogenic sources. Source identification studies suggest that the PAHs were mainly from motor vehicles and biomass/coal combustion. The incremental lifetime cancer risks associated with exposure to PAHs in the dustfall ranged from 10(-4) to 10(-6); these indicate potentially serious carcinogenic risks for exposed populations in the industrial corridor.

Historical polycyclic aromatic and petrogenic hydrocarbon loading in Northern Central Gulf of Mexico shelf sediments.

PubMed

Overton, E B; Ashton, B M; Miles, M S

2004-10-01

The distribution of selected hydrocarbons within ten dated sediment cores taken from the Mississippi River Bight off coastal Louisiana suggests a chronic contaminant loading from several sources including the river itself, oil and gas exploration in the central Gulf of Mexico (GOM) shelf area, and natural geologic hydrocarbon seeps. Data were grouped as either total polycyclic aromatic hydrocarbons (PAH's), which were indicative of pyrogenic PAH's; or estimated total hopanes (indicative of petrogenic hydrocarbons). The total PAH concentrations and estimated total hopanes begin increasing above background levels (approximately 200 ng g(-1)) after the 1950s. The distribution of these hydrocarbons and hopanes within the dated sediment cores suggests that the Mississippi River is a regional source of pyrogenic PAH's, and that the hopanes are from natural geologic hydrocarbon seeps, oil and gas exploration in the GOM, or both.

Polycyclic Aromatic Hydrocarbons in Electrocautery Smoke during Peritonectomy Procedures

PubMed Central

Näslund Andréasson, Sara; Mahteme, Haile; Sahlberg, Bo; Anundi, Helena

2012-01-01

Objective. This study identified and quantified polycyclic aromatic hydrocarbons (PAHs) in electrocautery smoke during 40 peritonectomy procedures and investigated any correlations and/or differences between levels of PAHs and perioperative variables. Methods. PAHs were measured in personal and stationary sampling by 40 mm Millipore cassettes, for adsorption of both gaseous and particle-bound PAHs. Results. All 16 USEPA priority pollutant PAHs were detected during peritonectomy procedures, naphthalene being the most abundant. For the only two PAHs with Swedish occupational exposure limits (OELs), benzo[a]pyrene and naphthalene, limits were never exceeded. Amount of bleeding was the only perioperative variable that correlated with levels of PAHs. Conclusions. Low levels of PAHs were detected in electrocautery smoke during peritonectomy procedures, and an increased amount of bleeding correlated with higher levels of PAHs. For evaluation of long-term health effects, more studies are needed. PMID:22685482

Evaluation of 1-hydroxypyrene as a biological marker of industrial exposure to polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Calderon, Francisco M.

1993-03-01

One hundred twenty-two workers (sixteen from a coke production plant and 106 from a graphite electrode manufacturing plant) agreed to participate in this study evaluating the relationship between exposure to polycyclic aromatic hydrocarbons (PAHs) and urinary excretion of 1-hydroxypyrene (1-HOP), the main metabolite of pyrene. The results show that the concentration of pyrene in air is highly correlated with total PAHs (r equals 0.83, P < 0.0001). The correlation coefficient between pyrene in air and 1-HOP is (r equals 0.69, P < 0.0001) and between 1-HOP and total PAHs is (r equals 0.77, P < 0.0001). The biological half life of the 1-HOP was determined (18 hrs) and the noninterference of smoking habits in relation to 1-HOP urinary excretion was established, concluding that 1-HOP is a suitable bioindicator of the occupational exposure to PAHs.

1-hydroxypyrene as a biomarker of occupational exposure to polycyclic aromatic hydrocarbons (PAH) in boilermakers.

PubMed

Mukherjee, Sutapa; Rodrigues, Ema; Weker, Robert; Palmer, Lyle J; Christiani, David C

2002-12-01

A repeated measures short-term prospective study was performed in boilermakers to determine occupational polycyclic aromatic hydrocarbon (PAH) exposure using the biomarker, 1-hydroxypyrene (1-OHP). Two work sites were studied; an apprentice school (metal fume exposure) and a boiler overhaul (residual oil fly ash [ROFA] and metal fume exposure). Pre- and postshift urine samples (n = 241; 41 male subjects) were analyzed for cotinine and 1-OHP. Descriptive statistics and generalized estimating equations were calculated. At the apprentice school cross-shift 1-OHP levels did not significantly differ. At the overhaul 1-OHP levels increased during the week in smokers and nonsmokers; in nonsmokers the 1-OHP level increased significantly postshift compared to preshift. In conclusion this study suggests that boilermakers exposed to occupational particulates are exposed to PAH. The urinary 1-OHP level may be a useful biomarker of PAH exposure in boilermakers exposed to ROFA, particularly in nonsmokers.

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

NASA Astrophysics Data System (ADS)

Prahl, Fredrick G.; Carpenter, Roy

1983-06-01

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 organic C- and lignin-rich panicles of density ≤ 1.9 g/cc. These particles, which include primarily vascular plant remains and bits of charcoal, comprise less than 1% of the total sediment weight. In contrast, a series of methylated phenanthrene homologs, possibly of fossil origin, are concentrated in some component of the more dense, lithic matrix of the sediment. Equilibrium models of PAH sorption/desorption from aqueous phase onto small particles of high surface area do not appear applicable to the behavior of the major PAH types identified in this aquatic environment.

Coupled LC-GC techniques for the characterisation of polycyclic aromatic compounds in fuel materials

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

Askey, S.A.; Holden, K.M.L.; Bartle, K.D.

1995-12-31

Exposure to polycyclic aromatic compounds (PAC) has long been identified as of considerable environmental concern. Originating from both natural and anthropogenic sources, many PAC exhibit significant carcinogenic and mutagenic properties. Multi-dimensional chromatographic techniques which provide separation by virtue of chemical class (group-type) or by molecular mass greatly simplifies the analysis of inherently complex fuel materials. In this study, on-line LC-GC techniques in which high resolution gas chromatography (HPLC) have been investigated. Comprehensive characterisation of fuel feedstocks and post-pyrolysis and combustion products was achieved by coupling LC-GC to low resolution ion trap mass spectrometry (ITD-MS) and atomic emission detection (AED). Themore » identification of PAC in diesel and coal materials, as well as urban air and diesel exhaust particulate extracts has provided valuable insight into the source, formation and distribution of such compounds pre- and post processing.« less

Polycyclic aromatic hydrocarbons (PAHs) in wild marine organisms from South China Sea: Occurrence, sources, and human health implications.

PubMed

Ke, Chang-Liang; Gu, Yang-Guang; Liu, Qi; Li, Liu-Dong; Huang, Hong-Hui; Cai, Nan; Sun, Zhi-Wei

2017-04-15

Concentrations of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) were measured in 15 marine wild organism species from South China Sea. The concentration (dry weight) of 16 PAHs ranged from 94.88 to 557.87ng/g, with a mean of 289.86ng/g. The concentrations of BaP in marine species were no detectable. The composition of PAHs was characterized by the 2- and 3-ring PAHs in marine species, and NA, PHE and FA were the dominant constituents. PAHs isomeric ratios indicated PAHs mainly originated from grass, wood and coal combustion, and petroleum. The human health risk assessment based on the excess cancer risk (ECR) suggested the probability of PAHs posing carcinogenic risk to human beings with consumption of marine organisms were negligible (probability<1×10 -6 ). Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimation and characterization of polycyclic aromatic hydrocarbons from magnesium metallurgy facilities in China.

PubMed

Nie, Zhiqiang; Yang, Yufei; Tang, Zhenwu; Liu, Feng; Wang, Qi; Huang, Qifei

2014-11-01

Field monitoring was conducted to develop a polycyclic aromatic hydrocarbon (PAH) emission inventory for the magnesium (Mg) metallurgy industry in China. PAH emissions in stack gas and fly/bottom ash samples from different smelting units of a typical Mg smelter were measured and compared. Large variations of concentrations, congener patterns, and emission factors of PAHs during the oxidation and reduction stages in the Mg smelter were observed. The measured average emission factor (166,487 μg/t Mg) was significantly higher than those of other industrial sources. Annual emission from Mg metallurgy in 2012 in China was estimated at 116 kg (514 g BaPeq) for PAHs. The results of this study suggest that PAH emission from Mg industries should be considered by local government agencies. These data may be helpful for understanding PAH levels produced by the Mg industry and in developing a PAH inventory.

Rational engineering of the fungal P450 monooxygenase CYP5136A3 to improve its oxidizing activity toward polycyclic aromatic hydrocarbons.

PubMed

Syed, Khajamohiddin; Porollo, Aleksey; Miller, David; Yadav, Jagjit S

2013-09-01

A promising polycyclic aromatic hydrocarbon-oxidizing P450 CYP5136A3 from Phanerochaete chrysosporium was rationally engineered to enhance its catalytic activity. The residues W129 and L324 found to be critical in substrate recognition were transformed by single (L324F) and double (W129L/L324G, W129L/L324F, W129A/L324G, W129F/L324G and W129F/L324F) mutations, and the engineered enzyme forms were expressed in Pichia pastoris. L324F and W129F/L324F mutations enhanced the oxidation activity toward pyrene and phenanthrene. L324F also altered the regio-selectivity favoring C position 4 over 9 for hydroxylation of phenanthrene. This is the first instance of engineering a eukaryotic P450 for enhanced oxidation of these fused-ring hydrocarbons.

Spatial mapping of lead, arsenic, iron, and polycyclic aromatic hydrocarbon soil contamination in Sydney, Nova Scotia: community impact from the coke ovens and steel plant.

PubMed

Lambert, Timothy W; Boehmer, Jennifer; Feltham, Jason; Guyn, Lindsay; Shahid, Rizwan

2011-01-01

This paper presents spatial maps of the arsenic, lead, and polycyclic aromatic hydrocarbon (PAH) soil contamination in Sydney, Nova Scotia, Canada. The spatial maps were designed to create exposure cohorts to help understand the observed increase in health effects. To assess whether contamination can be a proxy for exposures, the following hypothesis was tested: residential soils were impacted by the coke oven and steel plant industrial complex. The spatial map showed contaminants are centered on the industrial facility, significantly correlated, and exceed Canadian health risk-based soil quality guidelines. Core samples taken at 5-cm intervals suggest a consistent deposition over time. The concentrations in Sydney significantly exceed background Sydney soil concentrations, and are significantly elevated compared with North Sydney, an adjacent industrial community. The contaminant spatial maps will also be useful for developing cohorts of exposure and guiding risk management decisions.

Characterization of polycyclic aromatic hydrocarbons and carbonyl compounds in diesel exhaust emissions.

PubMed

Mabilia, Rosanna; Cecinato, Angelo; Tomasi Scianò, Maria Concetta; Di Palo, Vincenzo; Possanzini, Massimiliano

2004-01-01

Exhaust emissions from a recent model heavy-duty diesel vehicle (city bus) in a chassis dynamometer were measured during a transient driving cycle. Particle-bound polycyclic aromatic hydrocarbons (PAHs) and gaseous carbonyls, substances that create health hazards and are, as yet, unregulated were collected, the former on filters and the latter on dinitrophenylhydrazine (DNPH)-coated silica cartridges and analysed by GC-MS and HPLC, respectively. PAH emission rates decreased with the number of benzene fused rings. They averaged 0.2 mg km(-1) for a total of 11 PAHs ranging from fluoranthene to benzo(ghi)perylene. Fluoranthene and pyrene accounted for 90% of total PAHs. The sum of emission rates of C1 approximately C6 carbonyls averaged 174 mg km(-1), even if formaldehyde alone represented approximately 70% of the total carbonyl mass, followed by acetaldehyde (13%). Results obtained were compared with emission data reported in previous studies.

Interstellar Polycyclic Aromatic Compounds and Astrophysics

NASA Technical Reports Server (NTRS)

Hudgins, Douglas M.; DeVincenzi, Donald (Technical Monitor)

2001-01-01

Over the past fifteen years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role polycyclic aromatic compounds (PAC) in the interstellar medium (ISM). Twenty years ago, the notion of an abundant population of large, carbon rich molecules in the ISM was considered preposterous. Today, the unmistakable spectroscopic signatures of PAC - shockingly large molecules by previous interstellar chemistry standards - are recognized throughout the Universe. In this paper, we will examine the interstellar PAC model and its importance to astrophysics, including: (1) the evidence which led to inception of the model; (2) the ensuing laboratory and theoretical studies of the fundamental spectroscopic properties of PAC by which the model has been refined and extended; and (3) a few examples of how the model is being exploited to derive insight into the nature of the interstellar PAC population.

Analysis of polycyclic aromatic hydrocarbons in water and beverages using membrane-assisted solvent extraction in combination with large volume injection-gas chromatography-mass spectrometric detection.

PubMed

Rodil, Rosario; Schellin, Manuela; Popp, Peter

2007-09-07

Membrane-assisted solvent extraction (MASE) in combination with large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS) was applied for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. The MASE conditions were optimized for achieving high enrichment of the analytes from aqueous samples, in terms of extraction conditions (shaking speed, extraction temperature and time), extraction solvent and composition (ionic strength, sample pH and presence of organic solvent). Parameters like linearity and reproducibility of the procedure were determined. The extraction efficiency was above 65% for all the analytes and the relative standard deviation (RSD) for five consecutive extractions ranged from 6 to 18%. At optimized conditions detection limits at the ng/L level were achieved. The effectiveness of the method was tested by analyzing real samples, such as river water, apple juice, red wine and milk.

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

PubMed

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

2014-08-22

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

Polycyclic aromatic hydrocarbon levels and risk assessment for food from service facilities in Korea.

PubMed

Park, Shin-Woong; Jeong, Jun-Hyun; Her, Jae-Young; Kim, Mina K; Lee, Kwang-Geun

2017-06-01

In this study, levels of benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene (BaP), dibenzo[a,h]anthracene, benzo[g,h,i]perylene and indeno[1,2,3-c,d]pyrene in 412 food items collected from food service facilities in Korea were analysed. The concentrations of the eight polycyclic aromatic hydrocarbons (PAHs) ranged 0.13-0.48 μg/kg. The concentrations of benzo[a]pyrene in all food samples were <1 μg/kg, which is the lowest maximum limit in foods regulated by European Union legislation. PAH contents were employed to conduct exposure and risk assessment. The chronic daily intake of PAHs from 412 food samples was 5.48 × 10 -6 -4.70 ×x 10 -4  µg-TEQ BaP /kg/day with margins of exposure of 1.04 × 10 9 -1.16 × 10 11 .

Fullerene-like chemistry at the interior carbon atoms of an alkene-centered C26H12 geodesic polyarene.

PubMed

Bronstein, Hindy E; Scott, Lawrence T

2008-01-04

The title compound (1) undergoes 1,2-addition reactions of both electrophilic and nucleophilic reagents preferentially at the "interior" carbon atoms of the central 6:6-bond to give fullerene-type adducts 2, 3, 4, and 5. Such fullerene-like chemistry is unprecedented for a topologically 2-dimensional polycyclic aromatic hydrocarbon and qualifies this geodesic polyarene as a "bridge" between the old flat world of polycyclic aromatic hydrocarbons (PAHs) and the new round world of fullerenes. The relief of pyramidalization strain, as in the addition reactions of fullerenes, presumably contributes to the atypical mode of reactivity seen in 1. Molecular orbital calculations, however, reveal features of the nonalternant pi system in 1 that may also play an important role. Thus, the fullerene-like chemistry of 1 may be driven by two or more factors, the relative importances of which are difficult to discern.

Identification and characterization of epoxide hydrolase activity of polycyclic aromatic hydrocarbon-degrading bacteria for biocatalytic resolution of racemic styrene oxide and styrene oxide derivatives.

PubMed

Woo, Jung-Hee; Kwon, Tae-Hyung; Kim, Jun-Tae; Kim, Choong-Gon; Lee, Eun Yeol

2013-04-01

A novel epoxide hydrolase (EHase) from polycyclic aromatic hydrocarbon (PAH)-degrading bacteria was identified and characterized. EHase activity was identified in four strains of PAH-degrading bacteria isolated from commercial gasoline and oil-contaminated sediment based on their growth on styrene oxide and its derivatives, such as 2,3- and 4-chlorostyrene oxides, as a sole carbon source. Gordonia sp. H37 exhibited high enantioselective hydrolysis activity for 4-chlorostyrene oxide with an enantiomeric ratio of 27. Gordonia sp. H37 preferentially hydrolyzed the (R)-enantiomer of styrene oxide derivatives resulting in the preparation of a (S)-enantiomer with enantiomeric excess greater than 99.9 %. The enantioselective EHase activity was identified and characterized in various PAH-degrading bacteria, and whole cell Gordonia sp. H37 was employed as a biocatalyst for preparing enantiopure (S)-styrene oxide derivatives.

Particulate matter and polycyclic aromatic hydrocarbons in a selected athletic hall: ambient concentrations, origin and effects on human health

NASA Astrophysics Data System (ADS)

Kuskowska, Karolina; Rogula-Kozłowska, Wioletta; Rogula-Kopiec, Patrycja

2018-01-01

The paper presents the results of research on the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) associated with total suspended particles (TSP) and their respirable fraction (PM4) in one of the Warsaw sports halls. Samples of dust were collected for 15 days simultaneously inside and outside (atmospheric air) of the sports hall. The obtained data allowed calculating diagnostic ratios indicating the origin of the PAHs and selected indicators of cumulative exposure to the PAH mixture. Both PM and PAH in the surveyed area were derived from the combustion of solid fuels; this involved pollution both in the atmospheric air and in the air inside the sports hall. It has been shown that the exposure of sports hall users to PAHs is significantly higher than the exposure resulting from concentrations recorded in the atmospheric air.

Real-time monitoring of polycyclic aromatic hydrocarbons and respirable suspended particles from environmental tobacco smoke in a home

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

Ott, W.; Wilson, N.K.; Klepeis, N.

Real-time measurement of polycyclic aromatic hydrocarbons (PAH) on fine particles was evaluated in a home with environmental tobacco smoke (ETS) as a source. Respirable suspended particles (RSP) were also monitored. Comparison of PAH and RSP concentrations from these experiments suggests: (1) the PAH concentrations for the two types of cigarettes--a regular Marlboro filter cigarette and a University of Kentucky reference cigarette No. 2R1--were similar, but the RSP concentrations were different; (2) concentrations from the real-time PAH monitor were linearly related to RSP concentrations; (3) the slopes of the regression lines between PAH and RSP differed for the two types ofmore » cigarettes. The real-time PAH monitor appears to be a useful tool for evaluating mathematical models to predict the concentration time series in indoor microenvironments.« less

Infrared frequencies and intensities for astrophysically important polycyclic aromatic hydrocarbon cations

NASA Technical Reports Server (NTRS)

Szczepanski, Jan; Vala, Martin

1993-01-01

Polycyclic aromatic hydrocarbons (PAHs) have been implicated as the carriers of the 'unidentified infrared' (UIR) emission bands observed from the interstellar medium. It has long been thought that these molecules, if present, probably exist as cations. In this paper we present infrared spectra of the cations of five moderate-sized PAHs. The PAH cations have been produced by low-energy electron impact and then trapped and stabilized in argon matrices at 12 K. To date, results have been obtained on naphthalene, anthracene, pyrene, perylene, and coronene. A common feature of the infrared spectra of all these cations is the very different intensity pattern of the ions compared to the neutral parents. Visible and (partial) infrared spectra of the coronene cation are also presented. It is shown that the out-of-plane CH bending mode shifts to a position very close to the UIR band at 11.3 microns. The astrophysical impact of these observations is discussed.

Polycyclic Aromatic Hydrocarbons in Coastal Sediment of Klang Strait, Malaysia: Distribution Pattern, Risk Assessment and Sources

PubMed Central

Tavakoly Sany, Seyedeh Belin; Hashim, Rosli; Salleh, Aishah; Rezayi, Majid; Mehdinia, Ali; Safari, Omid

2014-01-01

Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia). The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions), with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait. PMID:24747349

Polycyclic Aromatic Hydrocarbons and the Diffuse Interstellar Bands: a Survey

NASA Technical Reports Server (NTRS)

Salama, F.; Galazutdinov, G. A.; Krelowski, J.; Allamandola, L. J.; Musaev, F. A.; DeVincenzi, Donald L. (Technical Monitor)

1999-01-01

We discuss the proposal relating the origin of some of the diffuse interstellar bands (DIBs) to neutral and ionized polycyclic aromatic hydrocarbons (PAHs) present in interstellar clouds. Laboratory spectra of several PAHs, isolated at low temperature in inert gas matrices, are compared with an extensive set of astronomical spectra of reddened, early type stars. From this comparison, it is concluded that PAN ions are good candidates to explain some of the DIBs. Unambiguous assignments are difficult, however, due to the shift in wavelengths and the band broadening induced in the laboratory spectra by the solid matrix. Definitive band assignments and, ultimately, the test of the of the proposal that PAH ions carry some of the DIB must await the availability of gas-phase measurements in the laboratory. The present assessment offers a guideline for future laboratory experiments by allowing the preselection of promising PAH molecules to be studied in jet expansions.

Polycyclic aromatic hydrocarbon optical properties and contribution to the acceleration of stellar outflows

NASA Technical Reports Server (NTRS)

Cherchneff, Isabelle; Barker, John R.; Tielens, Alexander G. G. M.

1991-01-01

The optical constants of four polycyclic aromatic hydrocarbon (PAH) molecules (benzene, pyrene, pentacene, and coronene) are determined from their measured laboratory absorption spectra. The Planck mean of the radiation pressure cross section is computed for each molecule and for amorphous carbon (AC) grains, and semiempirically estimated for large PAH molecules up to 400 carbon atoms. Assuming that PAHs are present in carbon-rich stellar outflows, the radiation pressure forces acting on them are calculated and compared with the radiation forces on AC particles. The results show that PAHs possess very different optical properties from AC grains. Small PAHs may experience an 'inverse greenhouse' effect in the inner part of the envelope, as they decouple from the gas close to the photosphere. The radiation pressure force on PAHs is always much less than the force at work on AC grains, and PAH molecules do not affect significantly the dynamics of the outflow.

Clean Transfer of Wafer-Scale Graphene via Liquid Phase Removal of Polycyclic Aromatic Hydrocarbons.

PubMed

Kim, Hyun Ho; Kang, Boseok; Suk, Ji Won; Li, Nannan; Kim, Kwang S; Ruoff, Rodney S; Lee, Wi Hyoung; Cho, Kilwon

2015-05-26

Pentacene (C22H14), a polycyclic aromatic hydrocarbon, was used as both supporting and sacrificing layers for the clean and doping-free graphene transfer. After successful transfer of graphene to a target substrate, the pentacene layer was physically removed from the graphene surface by using intercalating organic solvent. This solvent-mediated removal of pentacene from graphene surface was investigated by both theoretical calculation and experimental studies with various solvents. The uses of pentacene and appropriate intercalation solvent enabled graphene transfer without forming a residue from the supporting layer. Such residues tend to cause charged impurity scattering and unintentional graphene doping effects. As a result, this clean graphene exhibited extremely homogeneous surface potential profiles over a large area. A field-effect transistor fabricated using this graphene displayed a high hole (electron) mobility of 8050 cm(2)/V·s (9940 cm(2)/V·s) with a nearly zero Dirac point voltage.

Adsorption of Polycyclic aromatic hydrocarbons (fluoranthene and anthracenemethanol) by functional graphene oxide and removal by pH and temperature-sensitive coagulation.

PubMed

Zhang, Caili; Wu, Lin; Cai, Dongqing; Zhang, Caiyun; Wang, Ning; Zhang, Jing; Wu, Zhengyan

2013-06-12

A new kind of functional graphene oxide with fine stability in water was fabricated by mixing graphene oxide (GO) and brilliant blue (BB) with a certain weight ratio. The adsorption performance of this mixture of BB and GO (BBGO) to polycyclic aromatic hydrocarbons (anthracenemethanol (AC) and fluoranthene (FL)) was investigated, and the results indicated BBGO possessed adsorption capacity of 1.676 mmol/g and removal efficiency of 72.7% as to AC and adsorption capacity of 2.212 mmol/g and removal efficiency of 93.2% as to FL. After adsorption, pH and temperature-sensitive coagulation (PTC) method was used to remove the AC/BBGO or FL/BBGO complex and proved to be an effective approach to flocculate the AC/BBGO or FL/BBGO complex into large flocs, which tended to be removed from the aqueous solution.

Polycyclic aromatic hydrocarbon pollution in the surface water and sediments of Chabahar Bay, Oman Sea.

PubMed

Agah, Homira; Mehdinia, Ali; Bastami, Kazem Darvish; Rahmanpour, Shirin

2017-02-15

In the present study, the concentrations and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in the water and surface sediments from the Chabahar Bay, Oman Sea, were investigated in May (premonsoon) and December (postmonsoon) 2012. The concentrations of PAHs in the surface water samples ranged from 1.7 to 2.8ngl -1 and from 0.04 to 59.6ngl -1 in pre- and postmonsoon, respectively. In general, the PAH levels of the water samples from Chabahar Bay were higher in postmonsoon than in premonsoon (p<0.05). The concentrations of PAHs in the sediment samples varied from undetectable levels to 92.8ngg -1 d.w. in both seasons. The seasonal comparison of the results in sediment samples showed that the overall concentration of PAH compounds was higher in the postmonsoon season (p<0.05). Copyright © 2016. Published by Elsevier Ltd.

Distribution of polycyclic aromatic hydrocarbons in Datuo karst Tiankeng of South China.

PubMed

Theodore, Oramah I; Qi, Shihua; Kong, Xiangsheng; Liu, Huafeng; Li, Jun; Li, Jie; Wang, Xiangqing; Wang, Yinhui

2008-10-01

Levels of polycyclic aromatic hydrocarbons (PAHs) were measured in surface soils of Datuo karst Tiankeng (large sinkholes) in South China with the use of a gas chromatography-mass spectroscopy (GC-MS) system. This paper provides data on the levels and distribution of PAHs from the top to the bottom of the Datuo karst Tiankeng. The results showed that the sum of the 16 EPA priority PAHs from the sampled locations from top to bottom had a relative increment in PAHs concentration. summation operatorPAHs ranged from 16.93 ng/g to 68.07 ng/g with a mean concentration of 42.15 ng/g. The correlated results showed the bottom of the large sinkhole, which accounts for the higher concentrations, probably acts like a trap for the PAHs. Thus, the low evaporation rate at the bottom may play a key role in controlling the high concentration of PAHs at the bottom.

Atypical kinetic behavior of chloroperoxidase-mediated oxidative halogenation of polycyclic aromatic hydrocarbons.

PubMed

Aburto, Jorge; Correa-Basurto, Jose; Torres, Eduardo

2008-12-01

We have identified an atypical kinetic behavior for the oxidative halogenation of several polycyclic aromatic hydrocarbons (PAHs) by chloroperoxidase (CPO) from Caldariomyces fumago. This behavior resembles the capacity of some members of the P450 family to simultaneously recognize several substrate molecules at their active sites. Indeed, fluorometric studies showed that PAHs exist in solution as monomers and pi-pi dimers that interact to different extents with CPO. The dissociation constants of dimerization were evaluated for every single PAH by spectrofluorometry. Furthermore, docking studies also suggest that CPO might recognize either one or two substrate molecules in its active site. The atypical sigmoidal kinetic behavior of CPO in the oxidative halogenation of PAHs is explained in terms of different kinetic models for non-heteroatomic PAHs (naphthalene, anthracene and pyrene). The results suggest that the actual substrate for CPO in this study was the pi-pi dimer for all evaluated PAHs.

Degradation of some representative polycyclic aromatic hydrocarbons by the water-soluble protein extracts from Zea mays L. cv PR32-B10.

PubMed

Barone, Roberto; de Biasi, Margherita-Gabriella; Piccialli, Vincenzo; de Napoli, Lorenzo; Oliviero, Giorgia; Borbone, Nicola; Piccialli, Gennaro

2016-10-01

The ability of the water-soluble protein extracts from Zea mais L. cv. PR32-B10 to degrade some representative polycyclic aromatic hydrocarbons (PAHs), has been evaluated. Surface sterilized seeds of corn (Zea mais L. Pioneer cv. PR32-B10) were hydroponically cultivated in a growth chamber under no-stressful conditions. The water-soluble protein extracts isolated from maize tissues showed peroxidase, polyphenol oxidase and catalase activities. Incubation of the extracts with naphthalene, fluorene, phenanthrene and pyrene, led to formation of oxidized and/or degradation products. GC-MS and TLC monitoring of the processes showed that naphthalene, phenanthrene, fluorene and pyrene underwent 100%, 78%, 92% and 65% oxidative degradation, respectively, after 120 min. The chemical structure of the degradation products were determined by (1)H NMR and ESI-MS spectrometry. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phytoremediation of polycyclic aromatic hydrocarbons (PAH) by cv. Crioula: A Brazilian alfalfa cultivar.

PubMed

Alves, Wilber S; Manoel, Evelin A; Santos, Noemi S; Nunes, Rosane O; Domiciano, Giselli C; Soares, Marcia R

2018-07-03

This work aimed to evaluate the phytoremediation capacity of the alfalfa cultivar Crioula in soils contaminated with polycyclic aromatic hydrocarbons (PAHs), primary pollutants with mutagenic and carcinogenic potential. Alfalfa was grown from seed for 40 days on soil amended with anthracene, pyrene, and phenanthrene. Soil and plant tissue was collected for biometric assay, dry mass analysis, and PAH analysis by liquid chromatography. Increased total PAH concentration was associated with decreases in plant biomass, height, and internode length. The Crioula cultivar had a satisfactory phytoremediation effect, reducing total PAH concentration (300 ppm) in the experimental soil by 85% in 20 days, and by more than 95% in 40 days. The PAH showed a tendency to be removed in the temporal order: phenanthrene before pyrene before anthracene, and the removal ratio was influenced by the initial soil concentration of each PAH.

Solid-state surface luminescence of polycyclic aromatic hydrocarbons adsorbed on cellulose diacetate matrices

NASA Astrophysics Data System (ADS)

Rogacheva, Svetlana M.; Shipovskaya, Anna B.; Volkova, Elena V.; Khurshudyan, Grachia N.; Suska-Malawska, Malgorzata; Gubina, Tamara I.

2018-04-01

The spectral-kinetic characteristics of luminescence of 17 polycyclic aromatic hydrocarbons (PAH) sorbed from a "water-organic solvent" medium on cellulose diacetate (CDA) matrices were studied. A significant increase in the fluorescence signal on the CDA matrix was observed for 13 PAHs in comparison with aqueous solutions. The highest detection sensitivity was found for pyrene, benzo(a)pyrene, and benzo(k)fluoranthene. The fluorescence spectra of two PAH indicator pairs (anthracene-phenanthrene and pyrene-fluoranthene) used to control toxicant emission sources were studied with the simultaneous presence of isomers in the analyte, depending on the excitation wavelength. For both isomer pairs, it has been found that the spectra of their solid-state luminescence overlap insignificantly, the characteristic peaks do not coincide and do not overlap, the sensitivities of detection are close to each other, which makes it possible to consider this technique as promising to control PAH contamination sources.

Gas-particle distributions, sources and health effects of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in Venice aerosols.

PubMed

Gregoris, Elena; Argiriadis, Elena; Vecchiato, Marco; Zambon, Stefano; De Pieri, Silvia; Donateo, Antonio; Contini, Daniele; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

2014-04-01

Air samples were collected in Venice during summer 2009 and 2012 to measure gas and particulate concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). PCB-11, considered a marker for non-Aroclor contamination of the environment, was found for the first time in the Venetian lagoon and in Europe. An investigation on sources has been conducted, evidencing traffic as the major source of PAHs, whereas PCBs have a similar composition to Aroclor 1248 and 1254; in 2009 a release of PCN-42 has been hypothesized. Toxicological evaluation by TCA and TEQ methods, conducted for the first time in Venice air samples, identified BaP, PCB-126 and PCB-169 as the most important contributors to the total carcinogenic activity of PAHs and the total dioxin-like activity of PCBs and PCNs. Copyright © 2014 Elsevier B.V. All rights reserved.

Formation of H{sub 2} from internally heated polycyclic aromatic hydrocarbons: Excitation energy dependence

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

Chen, T., E-mail: tao.chen@fysik.su.se, E-mail: henning@fysik.su.se; Gatchell, M.; Stockett, M. H.

2015-04-14

We have investigated the effectiveness of molecular hydrogen (H{sub 2}) formation from Polycyclic Aromatic Hydrocarbons (PAHs) which are internally heated by collisions with keV ions. The present and earlier experimental results are analyzed in view of molecular structure calculations and a simple collision model. We estimate that H{sub 2} formation becomes important for internal PAH temperatures exceeding about 2200 K, regardless of the PAH size and the excitation agent. This suggests that keV ions may effectively induce such reactions, while they are unlikely due to, e.g., absorption of single photons with energies below the Lyman limit. The present analysis alsomore » suggests that H{sub 2} emission is correlated with multi-fragmentation processes, which means that the [PAH-2H]{sup +} peak intensities in the mass spectra may not be used for estimating H{sub 2}-formation rates.« less

The C-H Stretching Features at 3.2--3.5 μm of Polycyclic Aromatic Hydrocarbons with Aliphatic Sidegroups

NASA Astrophysics Data System (ADS)

Yang, X. J.; Li, Aigen; Glaser, R.; Zhong, J. X.

2016-07-01

The so-called “unidentified” infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 μm are ubiquitously seen in a wide variety of astrophysical regions. The UIE features are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials, e.g., polycyclic aromatic hydrocarbon (PAH) molecules. The 3.3 μm aromatic C-H stretching feature is often accompanied by a weaker feature at 3.4 μm. The latter is generally thought to result from the C-H stretch of aliphatic groups attached to the aromatic systems. The ratio of the observed intensity of the 3.3 μm aromatic C-H feature to that of the 3.4 μm aliphatic C-H feature allows one to estimate the aliphatic fraction of the UIE carriers, provided that the intrinsic oscillator strengths of the 3.3 μm aromatic C-H stretch ({A}3.3) and the 3.4 μm aliphatic C-H stretch ({A}3.4) are known. While previous studies on the aliphatic fraction of the UIE carriers were mostly based on the {A}3.4/{A}3.3 ratios derived from the mono-methyl derivatives of small PAH molecules, in this work we employ density functional theory to compute the infrared vibrational spectra of PAH molecules with a wide range of sidegroups including ethyl, propyl, butyl, and several unsaturated alkyl chains, as well as all the isomers of dimethyl-substituted pyrene. We find that, except for PAHs with unsaturated alkyl chains, the corresponding {A}3.4/{A}3.3 ratios are close to that of mono-methyl PAHs. This confirms the predominantly aromatic nature of the UIE carriers previously inferred from the {A}3.4/{A}3.3 ratio derived from mono-methyl PAHs.

Rapid estimation of concentration of aromatic classes in middistillate fuels by high-performance liquid chromatography

NASA Technical Reports Server (NTRS)

Otterson, D. A.; Seng, G. T.

1985-01-01

An high performance liquid chromatography (HPLC) method to estimate four aromatic classes in middistillate fuels is presented. Average refractive indices are used in a correlation to obtain the concentrations of each of the aromatic classes from HPLC data. The aromatic class concentrations can be obtained in about 15 min when the concentration of the aromatic group is known. Seven fuels with a wide range of compositions were used to test the method. Relative errors in the concentration of the two major aromatic classes were not over 10 percent. Absolute errors of the minor classes were all less than 0.3 percent. The data show that errors in group-type analyses using sulfuric acid derived standards are greater for fuels containing high concentrations of polycyclic aromatics. Corrections are based on the change in refractive index of the aromatic fraction which can occur when sulfuric acid and the fuel react. These corrections improved both the precision and the accuracy of the group-type results.

Salting-out assisted liquid-liquid extraction and partial least squares regression to assay low molecular weight polycyclic aromatic hydrocarbons leached from soils and sediments

NASA Astrophysics Data System (ADS)

Bressan, Lucas P.; do Nascimento, Paulo Cícero; Schmidt, Marcella E. P.; Faccin, Henrique; de Machado, Leandro Carvalho; Bohrer, Denise

2017-02-01

A novel method was developed to determine low molecular weight polycyclic aromatic hydrocarbons in aqueous leachates from soils and sediments using a salting-out assisted liquid-liquid extraction, synchronous fluorescence spectrometry and a multivariate calibration technique. Several experimental parameters were controlled and the optimum conditions were: sodium carbonate as the salting-out agent at concentration of 2 mol L- 1, 3 mL of acetonitrile as extraction solvent, 6 mL of aqueous leachate, vortexing for 5 min and centrifuging at 4000 rpm for 5 min. The partial least squares calibration was optimized to the lowest values of root mean squared error and five latent variables were chosen for each of the targeted compounds. The regression coefficients for the true versus predicted concentrations were higher than 0.99. Figures of merit for the multivariate method were calculated, namely sensitivity, multivariate detection limit and multivariate quantification limit. The selectivity was also evaluated and other polycyclic aromatic hydrocarbons did not interfere in the analysis. Likewise, high performance liquid chromatography was used as a comparative methodology, and the regression analysis between the methods showed no statistical difference (t-test). The proposed methodology was applied to soils and sediments of a Brazilian river and the recoveries ranged from 74.3% to 105.8%. Overall, the proposed methodology was suitable for the targeted compounds, showing that the extraction method can be applied to spectrofluorometric analysis and that the multivariate calibration is also suitable for these compounds in leachates from real samples.

Mid-Infrared Spectroscopy of Polycyclic Aromatic Nitrogen Heterocycles (PANHS) and their Ions

NASA Technical Reports Server (NTRS)

Mattioda, Andrew L.; Hudgin, Douglas; Bauschlicher, Charles W.; Alamandola, Louis J.

2003-01-01

In recent years, polycyclic aromatic nitrogen heterocycles (PANHs) have attracted a good deal of attention because of their potent carcinogenic and mutagenic properties, and their prevalence in our environment. Such species also play a prominent role in the chemistry of life up to and including the very nucleobases from which our DNA is constructed. Surprisingly, these compounds may even be common outside of our terrestrial environment. To wit, it is now widely accepted that polycyclic aromatic materials are abundant in space and represent a major reservoir of organic carbon in the interstellar medium and developing planetary systems. Given that nitrogen is the fourth most abundant chemically reactive element in space (surpassed only by hydrogen, carbon, and oxygen), it is entirely reasonable to suspect that PANHs may represent an important component of that organic reservoir. Motivated by their intrinsic merit and with special attention toward evaluating their exobiological significance, we have initiated a program to study the spectroscopic and chemical properties of P A " s under conditions relevant to extraterrestrial environments. Here we present the first results of that program-infrared spectroscopic measurements on a series of PANH"s in neutral and cationic forms, isolated in inert matrices at cryogenic temperatures.temperatures. The species studied include: 1 -, and 2-azabenz[a]anthracene, 1-, 2-, and 4- azachrysene, dibenz[a,h]acridine, and dibenz[a,J)acridine. The experimental measurements are also compared with theoretical spectra calculated using density functional theory. General spectroscopic trends observed in this series of compounds are discussed and the implications of these results for Astrophysics and Exobiology are considered.

Combined effect of urinary monohydroxylated polycyclic aromatic hydrocarbons and impaired lung function on diabetes.

PubMed

Hou, Jian; Sun, Huizhen; Xiao, Lili; Zhou, Yun; Yin, Wenjun; Xu, Tian; Cheng, Juan; Chen, Weihong; Yuan, Jing

2016-07-01

Associations of type 2 diabetes with exposure to polycyclic aromatic hydrocarbons and reduced lung function have been reported. The aim of the present study was to investigate effect of reduced lung function and exposure to background PAHs on diabetes. A total of 2730 individuals were drawn from the Wuhan-Zhuhai (WHZH) Cohort Study (n=3053). Participants completed physical examination, measurement of lung function and urinary monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs). Risk factors for type 2 diabetes were identified by multiple logistic regression analysis, and the presence of additive interaction between levels of urinary OH-PAHs and lower lung function was evaluated by calculation of the relative excess risk due to interaction (RERI) and attributable proportion due to interaction (AP). Urinary OH-PAHs levels was positively associated with type 2 diabetes among individuals with impaired lung function (p<0.05). Forced expiratory volume in one second (FEV1, odd ratio (OR): 0.664, 95% confidence interval (CI): 0.491-0.900) and forced vital capacity (FVC, OR: 0.693, 95% CI: 0.537-0.893) were negatively associated with diabetes among individuals. Additive interaction of higher urinary levels of OH-PAHs and lower FVC (RERI: 0.679, 95% CI: 0.120-1.238); AP: 0.427, 95% CI: 0.072-0.782) was associated with diabetes. Exposure to background PAHs was related to diabetes among individuals with lower lung function. Urinary levels of OH-PAHs and reduced lung function had an additive effect on diabetes. Copyright © 2016 Elsevier Inc. All rights reserved.

Seawater Polluted with Highly Concentrated Polycyclic Aromatic Hydrocarbons Suppresses Osteoblastic Activity in the Scales of Goldfish, Carassius auratus.

PubMed

Suzuki, Nobuo; Sato, Masayuki; Nassar, Hossam F; Abdel-Gawad, Fagr Kh; Bassem, Samah M; Yachiguchi, Koji; Tabuchi, Yoshiaki; Endo, Masato; Sekiguchi, Toshio; Urata, Makoto; Hattori, Atsuhiko; Mishima, Hiroyuki; Shimasaki, Youhei; Oshima, Yuji; Hong, Chun-Sang; Makino, Fumiya; Tang, Ning; Toriba, Akira; Hayakawa, Kazuichi

2016-08-01

We have developed an original in vitro bioassay using teleost scale, that has osteoclasts, osteoblasts, and bone matrix as each marker: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Using this scale in vitro bioassay, we examined the effects of seawater polluted with highly concentrated polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) on osteoblastic and osteoclastic activities in the present study. Polluted seawater was collected from two sites (the Alexandria site on the Mediterranean Sea and the Suez Canal site on the Red Sea). Total levels of PAHs in the seawater from the Alexandria and Suez Canal sites were 1364.59 and 992.56 ng/l, respectively. We were able to detect NPAHs in both seawater samples. Total levels of NPAHs were detected in the seawater of the Alexandria site (12.749 ng/l) and the Suez Canal site (3.914 ng/l). Each sample of polluted seawater was added to culture medium at dilution rates of 50, 100, and 500, and incubated with the goldfish scales for 6 hrs. Thereafter, ALP and TRAP activities were measured. ALP activity was significantly suppressed by both polluted seawater samples diluted at least 500 times, but TRAP activity did not change. In addition, mRNA expressions of osteoblastic markers (ALP, osteocalcin, and the receptor activator of the NF-κB ligand) decreased significantly, as did the ALP enzyme activity. In fact, ALP activity decreased on treatment with PAHs and NPAHs. We conclude that seawater polluted with highly concentrated PAHs and NPAHs influences bone metabolism in teleosts.

Polycyclic aromatic hydrocarbons (PAHs) and their derivatives (oxygenated-PAHs, nitrated-PAHs and azaarenes) in size-fractionated particles emitted in an urban road tunnel

NASA Astrophysics Data System (ADS)

Alves, C. A.; Vicente, A. M. P.; Gomes, J.; Nunes, T.; Duarte, M.; Bandowe, B. A. M.

2016-11-01

A sampling campaign of size segregated particulate matter (PM0.5, PM0.5-1, PM1-2.5 and PM2.5-10) was carried out at two sites, one in a road tunnel (Braga, Portugal) and another at an urban background location in the neighbourhood. Particle-bound polycyclic aromatic compounds were extracted with organic solvents and analysed by gas chromatography-mass spectrometry. Twenty six parent and alkyl-polycyclic aromatic hydrocarbons (PAHs), 4 azaarenes (AZAs), 15 nitrated and 15 oxygenated derivatives (NPAHs and OPAHs) were analysed. On average, submicron particles (PM1) in the tunnel comprised 93, 91, 96 and 71% of the total PAHs, OPAHs, NPAHs and AZAs mass in PM10, respectively. Tunnel to outdoor PAH concentration ratios between 10 and 14 reveal the strong contribution of fresh exhaust emissions to the PM loads. The dominant PAHs in the tunnel were pyrene, retene and benzo[ghi]perylene, accounting for 20, 17 and 8% of the total PAH levels in PM10, respectively. Isomer ratios indicated the importance of unburnt fuel as a significant PAH source. The only NPAH consistently present in all samples was 5-nitroacenaphthene. Indanone and 1,8-naphthalic anhydride were the most abundant OPAHs, accounting for 25 and 17% of the total concentrations of this organic class, respectively. Other abundant OPAHs were 1,4-naphthoquinone, 9-fluorenone, 1,2-acenaphthylenequinone and 7H-benz[de]anthracene-7-one. Individual emission factors (μg veh- 1 km- 1) were estimated and compared with those obtained in other tunnel studies.

In Situ Hydrothermally Grown TiO2@C Core-Shell Nanowire Coating for Highly Sensitive Solid Phase Microextraction of Polycyclic Aromatic Hydrocarbons.

PubMed

Wang, Fuxin; Zheng, Juan; Qiu, Junlang; Liu, Shuqin; Chen, Guosheng; Tong, Yexiang; Zhu, Fang; Ouyang, Gangfeng

2017-01-18

Nanostructured materials have great potential for solid phase microextraction (SPME) on account of their tiny size, distinct architectures and superior physical and chemical properties. Herein, a core-shell TiO 2 @C fiber for SPME was successfully fabricated by the simple hydrothermal reaction of a titanium wire and subsequent amorphous carbon coating. The readily hydrothermal procedure afforded in situ synthesis of TiO 2 nanowires on a titanium wire and provided a desirable substrate for further coating of amorphous carbon. Benefiting from the much larger surface area of subsequent TiO 2 and good adsorption property of the amorphous carbon coating, the core-shell TiO 2 @C fiber was utilized for the SPME device for the first time and proved to have better performance in extraction of polycyclic aromatic hydrocarbons. In comparison to the polydimethylsiloxane (PDMS) and PDMS/divinylbenzene (DVB) fiber for commercial use, the TiO 2 @C fiber obtained gas chromatography responses 3-8 times higher than those obtained by the commercial 100 μm PDMS and 1-9 times higher than those obtained by the 65 μm PDMS/DVB fiber. Under the optimized extraction conditions, the low detection limits were obtained in the range of 0.4-7.1 ng L -1 with wider linearity in the range of 10-2000 ng L -1 . Moreover, the fiber was successfully used for the determination of polycyclic aromatic hydrocarbons in Pearl River water, which demonstrated the applicability of the core-shell TiO 2 @C fiber.

The Infrared Spectra of Polycyclic Aromatic Hydrocarbons with Excess Peripheral H Atoms (Hn-PAHs) and their Relation to the 3.4 and 6.9 µm PAH Emission Features

PubMed Central

Sandford, Scott A.; Bernstein, Max P.; Materese, Christopher K.

2015-01-01

Polycyclic aromatic hydrocarbons (PAHs) are likely responsible for the family of infrared emission features seen in a wide variety of astrophysical environments. A potentially important subclass of these materials are PAHs whose edges contain excess H atoms (Hn-PAHs). This type of compound may be present in space, but it has been difficult to assess this possibility because of a lack of suitable laboratory spectra to assist with analysis of astronomical data. We present 4000-500 cm−1 (2.5–20 µm) infrared spectra of 23 Hn-PAHs and related molecules isolated in argon matrices under conditions suitable for interpretation of astronomical data. Spectra of molecules with mixed aromatic and aliphatic domains show characteristics that distinguish them from fully aromatic PAH equivalents. Two major changes occur as PAHs become more hydrogenated: (1) aromatic C-H stretching bands near 3.3 µm weaken and are replaced with stronger aliphatic bands near 3.4 µm, and (2) aromatic C-H out-of-plane bending mode bands in the 11–15 µm region shift and weaken concurrent with growth of a strong aliphatic -CH2-deformation mode near 6.9 µm. Implications for interpreting astronomical spectra are discussed with emphasis on the 3.4 and 6.9 µm features. Laboratory data is compared with emission spectra from IRAS 21282+5050, an object with normal PAH emission features, and IRAS 22272+5435 and IRAS 0496+3429, two protoplanetary nebulae with abnormally large 3.4 µm features. We show that ‘normal’ PAH emission objects contain relatively few Hn-PAHs in their emitter populations, but less evolved protoplanetary nebulae may contain significant abundances of these molecules. PMID:26435553

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

EPA Science Inventory

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

EMERGING TECHNOLOGY SUMMARY: INNOVATIVE METHODS FOR BIOSLURRY TREATMENT

EPA Science Inventory

The tests reported herein were conducted by IT Corporation (IT), Knoxville, TN, to investigate the feasibility of combined biological and chemical treatments to treat polycyclic aromatic hydrocarbons (PAHs). Bioslurry treatment of PAH-contaminated soils was demonstrated under the...

MEASURING CONTAMINANT RESUSPENSION RESULTING FROM SEDIMENT CAPPING

EPA Science Inventory

This Sediment Issue summarizes two studies undertaken at marine sites by the National Risk Management Research Laboratory of U.S. EPA to evaluate the resuspension of surface materials contaminated with polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) b...

BIODEGRADATION OF SEDIMENT-BOUND PAHS IN FIELD-CONTAMINATED SEDIMENT

EPA Science Inventory

The biodegradation of polycyclic aromatic hydrocarbons (PAHs) has been reported to occur under aerobic, sulfate reducing, and denitrifying conditions. PAHs present in contaminated sites, however, are known for their persistence. Most published studies were conducted in systems wh...

The Arithmetic of Aromaticity.

ERIC Educational Resources Information Center

Glidewell, Christopher; Lloyd, Douglas

1986-01-01

Explores the extent to which, in polycyclic hydrocarbons, the total pi electron population tends to form small (4n plus 2) groups and avoid the formation of 4n groups. Also discusses the relation of this trend to resonance energy stabilizations. (JN)

METABOLISM AND GENOTOXICITY OF 1-NITROPYRENE

EPA Science Inventory

1-Nitropyrene (NP), a nitrated polycyclic aromatic hydrocarbon and a potent bacterial mutagen, has been identified in combustion emissions and may contribute to the burden of genotoxicity associated with air pollution. NP undergoes rapid metabolism by rat hepatic subcellular frac...

Determination of heavy polycyclic aromatic hydrocarbons by non-aqueous reversed phase liquid chromatography: Application and limitation in refining streams.

PubMed

Panda, Saroj K; Muller, Hendrik; Al-Qunaysi, Thunayyan A; Koseoglu, Omer R

2018-01-19

The heavy polycyclic aromatic hydrocarbons (HPAHs) cause detrimental effects to hydrocracker operations by deactivating the catalysts and depositing in the downstream of the reactor/ exchangers. Therefore, it is essential to continuously monitor the accumulation of HPAHs in a hydrocracker unit. To accurately measure the concentration of HPAHs, the development of a fast and reliable analytical method is inevitable. In this work, an analytical method based on non-aqueous reversed phase chromatography in combination with high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was developed. As a first step, five different types of stationary phases were evaluated for the separation of HPAHs in non-aqueous mode and the best suited phase was further used for the fractionation of HPAHs in a fractionator bottom sample obtained from a refinery hydrocracker unit. The eight major fractions or peaks obtained from the separation were further characterized by UV spectroscopy and FT-ICR MS and the compounds in the fractions were tentatively confirmed as benzoperylene, coronene, methylcoronene, naphthenocoronene, benzocoronene, dibenzoperylene, naphthocoronene and ovalene. The developed liquid chromatography method can be easily adapted in a refinery laboratory for the quantitation of HPAHs in hydrocracking products. The method was further tested to check the interference of sulfur aromatics and/or large alkylated aromatic hydrocarbons on the determination of HPAHs in hydrocracking products. Copyright © 2017 Elsevier B.V. All rights reserved.

Atmospheric behaviors of particulate-bound polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in Beijing, China from 2004 to 2010

NASA Astrophysics Data System (ADS)

Tang, Ning; Suzuki, Genki; Morisaki, Hiroshi; Tokuda, Takahiro; Yang, Xiaoyang; Zhao, Lixia; Lin, Jinming; Kameda, Takayuki; Toriba, Akira; Hayakawa, Kazuichi

2017-03-01

Airborne particulates were collected at an urban site (site 1) from 2004 to 2010 and at a suburban site (site 2) in 2010 in Beijing. Nine polycyclic aromatic hydrocarbons (PAHs) and five nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined by HPLC with fluorescence and chemiluminescence detection, respectively. The concentrations of PAHs and NPAHs were higher in heating season than in non-heating season at the two sites. Both the concentrations of PAHs and NPAHs decreased in the non-heating season but only the concentrations of NPAHs decreased in heating season at site 1, from 2004 to 2010. These findings suggest that source control measures implemented by the city of Beijing helped to reduce air pollution in Beijing. The concentrations of PAHs increased at site 1 in 2010, possibly because of the transport of emissions from windward other areas, such as Shanxi province. Several diagnostic ratios of PAHs and NPAHs showed that the different sources contributed to Beijing's air pollution, although coal combustion was the main source in the heating season and vehicle emission was the main source in the non-heating season. An analysis of physical parameters at Beijing showed that high wind speed can remove atmospheric PAHs and NPAHs in the heating season and that high relative humidity can remove them in the non-heating season.

Determination of particle-bound polycyclic aromatic hydrocarbons emitted from co-pelletization combustion of lignite and rubber wood sawdust

NASA Astrophysics Data System (ADS)

Kan, R.; Kaosol, T.; Tekasakul, P.; Tekasakul, S.

2017-09-01

Determination of particle-bound Polycyclic Aromatic Hydrocarbons (PAHs) emitted from co-pelletization combustion of lignite and rubber wood sawdust in a horizontal tube furnace is investigated using High Performance Liquid Chromatography with coupled Diode Array and Fluorescence Detection (HPLC-DAD/FLD). The particle-bound PAHs based on the mass concentration and the toxicity degree are discussed in the different size ranges of the particulate matters from 0.07-11 μm. In the present study, the particle-bound PAHs are likely abundant in the fine particles. More than 70% of toxicity degree of PAHs falls into PM1.1 while more than 80% of mass concentration of PAHs falls into PM2.5. The addition of lignite amount in the co-pelletization results in the increasing concentration of either 4-6 aromatic ring PAHs or high molecular weight PAHs. The high contribution of 4-6 aromatic ring PAHs or high molecular weight PAHs in the fine particles should be paid much more attention because of high probability of human carcinogenic. Furthermore, the rubber wood sawdust pellets emit high mass concentration of PAHs whereas the lignite pellets emit high toxicity degree of PAHs. By co-pelletized rubber wood sawdust with lignite (50% lignite pellets) has significant effect to reduce the toxicity degree of PAHs by 70%.

Spatial distribution and trends in trace elements, polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls in Lake Worth sediment, Fort Worth, Texas

USGS Publications Warehouse

Harwell, Glenn Richard; Van Metre, Peter C.; Wilson, Jennifer T.; Mahler, Barbara J.

2003-01-01

In spring 2000, the Texas Department of Health issued a fish consumption advisory for Lake Worth in Fort Worth, Texas, because of elevated concentrations of polychlorinated biphenyls (PCBs) in fish. In response to the advisory and in cooperation with the U.S. Air Force, the U.S. Geological Survey collected 21 surficial sediment samples and three gravity core sediment samples to assess the spatial distribution and historical trends of selected hydrophobic contaminants, including PCBs, and to determine, to the extent possible, sources of hydrophobic contaminants to Lake Worth. Compared to reference (background) concentrations in the upper lake, elevated PCB concentrations were detected in the surficial sediment samples collected in Woods Inlet, which receives surface runoff from Air Force facilities and urban areas. Gravity cores from Woods Inlet and from the main part of the lake near the dam indicate that the concentrations of PCBs were three to five times higher in the 1960s than in 2000. A regression method was used to normalize sediment concentrations of trace elements for natural variations and to distinguish natural and anthropogenic contributions to sediments. Concentrations of several trace elements—cadmium, chromium, copper, lead, and zinc—were elevated in sediments in Woods Inlet, along the shoreline of Air Force facilities, and in the main lake near the dam. Concentrations of these five trace elements have decreased since 1970. Polycyclic aromatic hydrocarbons also were elevated in the same areas of the lake. Concentrations of total polycyclic aromatic hydrocarbons, normalized with organic carbon, were mostly stable in the upper lake but steadily increased near the dam, except for small decreases since 1980. The Woods Inlet gravity core showed the largest increase of the three core sites beginning about 1940; total polycyclic aromatic hydrocarbon concentrations in post-1940 sediments from the core showed three apparent peaks about 1960, 1984, and 2000. The concentrations of organochlorine pesticides were low relative to consensus-based sediment-quality guidelines and either decreased or remained constant since 1970. The two likely sources of hydrophobic contaminants to the lake are urban areas around the lake and the drainage area of Meandering Road Creek that contributes runoff to Woods Inlet and includes Air Force facilities.