Ozonation of Polycyclic Aromatic Hydrocarbons in Water Solution

The degradation of three polycyclic aromatic hydrocarbons (PAHs): benzo[a]pyrene (BAP), chrysene (CHR), and fluorene (FLU) in aqueous solution using ozone was investigated. The influence of pH of the reaction mixture, ozone concentration, and the presence of a radical scavenger on the reaction rate was determined. The highest rate of PAHs disappearance was achieved in acidic solutions. The radical scavenger, tert-butanol, effectively inhibited the rate of PAHs destruction. The rate constants of direct reaction of PAHs with ozone were calculated and they were equal to (3.32 ± 0.21) × 10⁴; (1.10 ± 0.15) × 10⁴ and 44.8 ± 1.1 M^?1s^?1 for BAP, CHR, and FLU, respectively. The contributions of direct ozonolysis, and radical reaction to PAHs oxidation in ozonation processes, were evaluated.     

The Use of Spectrofluorimetry for Monitoring the Bioaccumulation and the Biotransformation of Polycyclic Aromatic Hydrocarbons in Daphnia magna

A rapid and direct spectrofluorimetric method was tested in order to monitor the bioaccumulation of PAHs in Daphnia magna in a control media. After exposure to water containing benzo[ a ]pyrene or fluoranthene, daphnids were put in solvent, sonicated, and filtered. The fluorescence spectrum observed in the filtrate was recorded. Results were compared to HPLC measurements of the same pools of organisms. In fluoranthene experiments, the fluorescence peak of the daphnid extract spectrum was linearly related to the PAH content as measured with HPLC. In benzo[ a ]pyrene experiments, other fluorescent compounds progressively appeared in the sample. They were assumed to be metabolites. A linear regression involving fluorescence intensities at two different wavelengths was necessary for a satisfactory correlation with HPLC measurements. A water extraction was performed to isolate metabolites. None or very few fluoranthene metabolites were isolated in the aqueous phase, whereas increasing benzo[ a ]pyrene metabolites were observed while the exposure time increased.     

Fluorescence and Raman Spectrometry of Polycyclic Aromatic Hydrocarbons in Biological Systems

Abstract

Fluorescence and Raman spectrometry were employed for the study of interactions of benzo[a]pyrene and pyrene with heme proteins in the presence of phospholipids. Since BP is asymmetrical and pyrene is symmetrical, dual maxima bands appear in the excimer of BP molecules and one single band in the excimer of pyrene. The metabolized BP molecules may mainly derive from the bilayer surface and with a proper orientation. BP molecules in other sites in the membrane will have to be transferred to these sites in order to be metabolized.     

Extraction of Polycyclic Aromatic Hydrocarbons in Barn Owls ( Tyto Alba ) from Northwest Spain by SFE and HPLC-FL Analysis

Supercritical fluid extraction (SFE) and high-performance liquid chromatography-fluorescence detection (HPLC-FL) were used to determine concentration of anthracene, benzo[ a ]anthracene, benzo[ a ]pyrene, benzo[ b ]fluoranthene, benzo[ ghi ]perylene, benzo[ k ]fluoranthene, chrysene, fluoranthene, pyrene, and indeno[1,2,3- cd ]pyrene in six classes of tissue (heart, liver, intestine, muscle, lung, and kidney) of 11 barn owls from Galicia (northwest Spain). We have detected fluoranthene and pyrene in >40.0% of samples, anthracene in 35.4%, and benzo[ a ]anthracene in 12.3%. Mean concentrations were between 0.398 w g/kg dry weight for anthracene and 4.855 w g/kg dry weight for fluoranthene. Lung and intestine tissues were more polluted than the other tissues.     

Determination of Semivolatile and Particulate Polycyclic Aromatic Hydrocarbons in SRM 1649a and PM 2.5 Samples by HPLC-Fluorescence

The concentrations of 15 "priority pollutant" semivolatile and particulate polycyclic aromatic hydrocarbons (PAHs) were determined in three sets of samples supplied by the National Institute for Standards and Technology (NIST) as part of an interlaboratory analytical exercise. The purpose of the exercise, organized by NIST and the U.S. Environmental Protection Agency, was to determine the comparability of measurements for various organic analytes among the participating laboratories, and to establish consensus values for SRM 1649a and interim materials. The commercially available SRM 1649a Atmospheric Urban Dust and two subsamples of this popular reference material were analyzed: an extract designated as Air Particulate Extract, and a resieved portion labeled Air Particulate I. The method used in our laboratory for the exercise consists of the extraction of the PAHs from the solid samples by ultrasonication, followed by separation and quantification using high-performance liquid chromatographyfluorescence detection. The accuracy and precision of the results obtained by our analytical protocol and by 14 other participating laboratories were evaluated using the International Union of Pure and Applied Chemistry guidelines of z-scores ( = 25% of the exercise assigned value) and p -scores. Using these guidelines the accuracy of our method provided results that are satisfactory for all 15 target PAHs (|z| h 2) determined in the Air Particulate Extract and, except for fluorene, in the Air Particulate I sample. Finally, application of the methodology is demonstrated for the quantification of PAHs present at the pg m m 3 range in PM 2.5 samples collected from 163 m 3 of air in the Los Angeles basin.     

Occurrence of Polycyclic Aromatic Hydrocarbons in Smoke Flavourings

The presence of Polycyclic Aromatic Hydrocarbons (PAHs) in four liquid smoke flavourings of different origins has been studied, in order to test whether a relation between their PAH content and their composition could be established, and to evaluate whether the use of these flavourings could involve a risk to human health. The samples were subjected to an alkaline treatment, extracted with cyclohexane, cleaned up, and the PAHs determined by gas chromatography-mass spectrometry. The results reveal a wide range of PAHs, especially in the commercial flavourings studied, which present higher concentrations of both total and carcinogenic PAHs than those obtained in the laboratory. Benzo(a)pyrene has been detected in three of the samples studied, but its levels do not exceed, in any of the cases, the 10 μg/kg value fixed by the FAO/WHO.     

Distribution of Polycyclic Aromatic Hydrocarbons in Surficial Sediments of the Vigo Estuary,Spain, Central Axis and Adjacent Shelf

For the first time, 13 polycyclic aromatic hydrocarbons (PAHs) have been identified in samples of surface sediments at 17 stations on the Vigo estuary (northwest Spain) and its adjacent shelf. The separation and quantification of the analyzed compounds were performed using high-performance liquid chromatography, and a fluorescence detector with wavelength programming. The values found, for the sum of the 13 PAHs, varied between 28 and 2,150 w g/kg dry weight. These concentrations may be considered to be between very low and medium when compared with other estuaries. A concentration gradient with lower values on the continental shelf, that increase as the distance to the city of Vigo decreases, may be appreciated. Variations also can be noted in the participation of each PAH in the total sum, as a consequence of the differing degradability levels of each compound.     

Comparative Metabolism,Bioavailability, and Toxicokinetics of Benzo[ a ]pyrene in Rats After Acute Oral,Inhalation, and Intravenous Administration

The metabolic fate of high doses of B a P is not fully established. To fill this important data need, a comprehensive metabolism, bioavailability, and toxicokinetic study has been undertaken to track the fate of B a P subsequent to single acute exposures. Doses of 100 mg/kg body weight, 0.1 mg/m 3 (equivalent to 19 mg/kg oral dose), and 4.5 w g/kg B a P were administered to 8-week-old male F-344 rats via oral, inhalation (nose only), and intravenous routes, respectively. Rats were sacrificed at 0, 0.5, 1, 2, 4, 6, 24, 48, and 72 hr postexposure. Blood, liver, lung, brain, reproductive tissues, urine, and feces samples were analyzed for parent B a P and metabolites by HPLC with fluorescence detection. Most of the administered B a P was metabolized 4, 6, and 72 hr postexposure for inhalation, intravenous, and oral routes, respectively. The following metabolites were detected: 4,5-dihydrodiol, 7,8-dihydrodiol, 9,10-dihydrodiol, 3,6-dione, 3-hydroxy, and 9-hydroxy B a P (organic fraction), glucuronides, sulfates, and glutathione conjugates (aqueous fraction). Toxicokinetic data revealed a high mean residence time, and low clearance values for B a P metabolites in lung, liver, and brain relative to plasma. Findings of this study establish the relationship between bioavailability and the acute toxic effects of B a P observed in our laboratory at these high doses.     

Effect of the Route of Administration on the Induction of Cytogenetic Damage and DNA Adducts in Peripheral Blood Lymphocytes of Rats and Mice by Polycyclic Aromatic Hydrocarbons

Experiments were designed to investigate how the route of exposure to polycyclic aromatic hydrocarbons (PAHs) in mice and rats affects the induction of cytogenetic end points and DNA adduction. Both mice and rats were exposed to 100 mg/kg of benz[ a ]anthracene (B[ a ]A), benzo[ b ]fluoranthene (B[ b ]F), benzo[ a ]pyrene (B[ a ]P), or chrysene (Chr) by gavage or by intraperitoneal injection (i.p.). Peripheral blood was removed by cardiac puncture 7 days after PAH administration. Blood samples were analyzed in parallel for sister chromatid exchange (SCE) frequency, the frequency of micronuclei in cytochalasin B-induced binucleate cells (MN bn ), and DNA adduction using 32P-postlabeling. The i.p. route of exposure produced both the highest levels of cytogenetic damage and DNA adducts for each PAH. The mouse was more sensitive than the rat to PAH exposure as measured by SCE induction and the total amount of DNA adducts/ w g DNA.     

Photodegradation Products of Polycyclic Aromatic Hydrocarbons in Water and Their Amenability to Biodegradation

Saturated water solutions of anthracene, pyrene, benz[ a ]anthracene, and dibenz[ a,h ]anthracene were UV-irradiated in the presence of oxygen and their photodegradation products were identified. The products were then individually photolyzed. Several products of photolysis were identified chromatographically. Furthermore, the biodegradation of two photoproducts, 9,10-anthracenedione and benz[ a ]anthracene-7,12-dione, was studied separately and in the presence of the original polycyclic aromatic hydrocarbons (PAHs). The irradiation of anthracene first produced 9,10-anthracenedione and continuous illumination yielded additionally 1-hydroxy-9,10-anthracenedione, 1,4-dihydroxy-9,10-anthracenedione, 9-anthrone, and 1(3H)-isobenzofuranone. Photolysis of benz[ a ]anthracene produced benz[ a ]anthracene-7,12-dione and 1(3H)-isobenzofuranone. By irradiation of pyrene and dibenz[ a,h ]anthracene mainly diones of the original compounds were formed. In batch vial experiments, the biodegradation of 9,10-anthracenedione alone started with no lag phase whereas biodegradation of anthracene alone had a lag of 40 days. The lag for benz[ a ]anthracene biodegradation was, in the presence and absence of benz[ a ]anthracene-7,12-dione, 17 and 35 days, respectively.     

High-Molecular-Weight Polycyclic Aromatic Hydrocarbons in the Area and Vicinity of the Deza Chemical Plant,Czech Republic

Polycyclic aromatic hydrocarbons (PAHs) with molecular weight exceeding 278 amu were analyzed in air, water, and soils from the area and vicinity of the DEZA Chemical Plant (Vala w ské Mezi q í ) í, Czech Republic). Air and water were sampled using semipermeable membrane devices (SPMDs); grab sampling was applied for soils. Laser desorption/ionization-time-of-flight mass spectrometry (LDI-TOF MS) and liquid chromatography/ion trap mass spectrometry with atmospheric pressure chemical ionization (LC/APCI-ITMS) were employed for the quick assessment of PAH distribution and for the identification and quantification of some high-molecular-weight PAHs. Compounds with molecular mass up to 450 u were found. LDI-TOF mass spectra and selected LC/APCI-ITMS profiles (m/z 303, m/z 327, and m/z 351) were compared to identify potential source of contamination in this locality. High-molecular-weight PAHs were found in all environmental compartments in the area studied; their levels were quite high close to their source and decreased sharply with increasing distance from it.     

Urban Runoff Contribution to Surface Sediment Accumulation for Polycyclic Aromatic Hydrocarbons in the Cotonou Lagoon,Benin

The carcinogenic and mutagenic properties of some polycyclic aromatic hydrocarbons (PAHs) and their widespread presence in the environment have led to many scientific investigations during the past three decades. In this study, surface sediments from six sampling sites in the Cotonou lagoon (three sites in the channel and three in Lake Nokoue) during the highest stormy season (May, June, and July) were used to assess the urban runoff contribution of PAH accumulation in this ecosystem. This assessment showed relatively high PAH loads (140-625 ng/g) during the rainy season and high inputs of organic materials (total organic carbon contents between 2.5 and 9.5% dry weight). Generally known as originating from different processes, PAHs detected in most of the Cotonou lagoon sampling sites were characterized by the predominance of the high-molecular-weight PAH over the low-molecular-weight PAH, which is an indicator of pyrolytic origin PAH inputs. PAH contamination in the Cotonou lagoon surface sediments was mainly from heavy urban traffic linked to the use of diesel vehicles and to the motorbike taxis proliferating across and around the city. Regression analysis carried out between total PAH concentration and total organic carbon contents showed, excluding the rural sampling site, a positive linear relationship for most samples ( R 2 = 0.9996), and confirmed the pyrogenic input of PAHs in the Cotonou lagoon. Mitigation measures were suggested to ameliorate the PAH pollution in the lagoon.     

Real-Time Monitoring of Polycyclic Aromatic Hydrocarbons in Cigarette Smoke Using Time-Resolved Laser-Induced Fluorescence

Cigarette smoke contains a large number of chemicals and gaseous compounds including polycyclic aromatic hydrocarbons (PAHs). Due to the importance of PAHs and their health effects in cigarettes, development of systems to analyze PAHs in cigarette smoke may become useful in developing a less harmful product. However, the complexity of cigarette smoke chemistry remains a significant obstacle in its analysis: many cigarette smoke components are produced due to reactions such as decomposition and recombination of cigarette components during the smoking process. Methods to analyze these reactions in real-time are needed. In this article the authors report direct monitoring of pyrene in mainstream smoke using time-gated laser-induced fluorescence (LIF) based on fiber optics. The time-gated detection system could provide a reduced background signal of mainstream smoke when using optimized gate delay and gate width parameters. The results demonstrate the feasibility of direct monitoring of PAHs in mainstream smoke.     

Levels of 15 + 1 EU Priority Polycyclic Aromatic Hydrocarbons in Different Edible Oils Available in the Syrian Market

ABSTRACT

The levels of 15 + 1 EU priority polycyclic aromatic hydrocarbons (15 + 1 EU PAHs) have been determined in different edible oils (extra virgin olive oil, virgin olive oil, sunflower oil, corn oil, and soybean oil) available in the Syrian market. The samples have been prepared by donor–acceptor complex chromatography and subsequently characterized by high-pressure liquid chromatography coupled with fluorescence and ultraviolet detection for quantification purposes. Variable levels of contamination have been found within different kinds of edible oil samples, and only chrysene has been detected in all the studied samples. Moreover, the mean total sum of 15 + 1 EU PAHs has shown variation from 29.8 µg/kg (corn oil) to 63.7 µg/kg (virgin olive oil). A total of 11 samples out of 38 samples (28.9%) have not fulfilled the European Union (EU) food law requirements. Nine samples have exceeded the EU legislation limit of benzo[a]pyrene (BaP) (2 µg/kg) and only two samples have exceeded the EU legislation limit of PAH4 (10 µg/kg) and had acceptable level of BaP. Finally, the mean and maximum dietary exposures of PAHs through consumption of edible oils have been estimated.     

Spectrochemical Evaluation of Diisopropylamine as a Selective Fluorescence Quenching Agent of Polycyclic Aromatic Hydrocarbons in Acetonitrile

The ability of diisopropylamine to selectively quench the fluorescence intensity of nonalternant as opposed to alternant polycyclic aromatic hydrocarbons (PAHs) dissolved in acetonitrile was investigated. Sixteen alternant PAHs and 14 nonalternant PAHs were examined. Five PAHs, which contain a fixed double bond in the cyclopenta ring, were also included in this study. The experimental results indicated, with few exceptions, that diisopropylamine selectively quenched the fluorescence emission intensity of nonalternant PAHs, leaving the fluorescence intensity of most alternant PAHs unaffected. These results also confirmed the classification of the PAHs that contain a fixed double bond in the five membered rings as alternant not nonalternant PAHs. Limitations in the use of diisopropylamine as a selective quenching agent were also studied. Diisopropylamine does not retain its selective fluorescence quenching ability for nonalternant PAHs in acidic media.     

Metabolization of the Polycyclic Aromatic Hydrocarbon Benzo( A )Pyrene by a Non-White Rot Fungus ( Fusarium Solani ) in a Batch Reactor

To investigate metabolization of benzo[ a ]pyrene (B a P), a high-molecular-weight polycyclic aromatic hydrocarbon consisting of five aromatic rings, by a Deuteromycete Fusarium solani , a culture with [7,10- 14 C]benzo[ a ]pyrene was carried out in a batch fermentor under cometabolic conditions. In spite of drastic culture conditions with a high load of B a P (302 mg in a 1.6 liters), analysis of the growth and substrate depletion kinetics showed a classical pattern. The evolution of 14 CO 2 release demonstrated that B a P mineralization by the non-white rot fungus F. solani occurred rapidly at early stages of fermentation (15 hr) during the germination process. At the end of fermentation, 1.2% of the B a P was evolved as 14 CO 2 and 5.3% was incorporated in biomass. B a P metabolization was also confirmed by isolating metabolic products, extracted from mycelia and identified as 1,6-benzo[ a ]pyrene quinone and 3,6-benzo[ a ]pyrene quinone, by mass and ultraviolet (UV) spectroscopic analyses.     

Problems in the Extraction of Polycyclic Aromatic Hydrocarbons from Diesel Particulate Matter

In this work, a comparison between Soxhlet, ultrasonic, and microwave-assisted extraction (MAE) (using hexane:acetone 1:1) of polycyclic aromatic hydrocarbons (PAHs) from SRM 1650 diesel particulate matter was made. As good recoveries were not obtained for the higher molecular weight compounds, MAE with toluene and dichloromethane was also tested. Achieved recoveries were compared with the results obtained in the same assays made with SRM 1648 urban particulate matter and real atmospheric particulate samples. In order to explain the difficulty of the extraction of PAHs from SRM 1650 in comparison to SRM 1648 and real atmospheric particulate samples, elemental analysis, X-ray diffraction, and particle analysis using scanning electron microscopy coupled to an automatic computer imaging system were also made. It is important to notice that SRM 1650 shows a high percentage of carbon and differences in the morphology of the particles between SRM 1650 and SRM 1648 were observed.     

AP-PCR Fingerprinting for Detection of Genetic Damage Caused by Polycyclic Aromatic Hydrocarbons

Exposure of organisms to genotoxic chemicals results in the formation of stable, covalently bound adducts between the chemical (or one of its metabolites) and the DNA, these adducts may cause mutations and cytogenetic changes. The primary effects of such exposure (i.e. adduct formation) and subsequent effects on the DNA (cytogenetic damage, mutation) may be monitored using a number of assays of varying sensitivity and specificity. Recent developments in molecular biology offer new possibilities for detecting DNA damage. We examined whether DNA fingerprinting by arbitrarily primed polymerase chain reaction (AP-PCR) can reveal differences in the DNA fingerprints of rats and shore crabs exposed to benzo[a]pyrene in the laboratory and of crabs from control and from polluted areas. The results indicate that differences between control and exposed animals were detectable and that DNA fingerprinting by AP-PCR offers a useful alternative biomarker assay for the detection of the genotoxic effects of environmental pollutants.     

Tumorigenicity of Fjord Region Diol Epoxides of Polycyclic Aromatic Hydrocarbons

(±)-anti-Benzo[c]phenanthrene-3,4-diol-1,2-epoxide (BcPDE), (±)-anti-benzo[g]-chrysene-11,12-diol-13,14-epoxide (BgCDE), and (±)-anti-dibenzo[a,l]pyrene-11,12-diol-13,14-epoxide (DB[a,l]PDE) were synthesized for use in biological assays. To compare mammary carcinogenicity, BcPDE and (±)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) were tested by direct application to the mammary glands of female CD rats at a total dose of 12.2 μmol per animal. 6-Nitrochrysene (6-NC) at the same dose was used as a positive control. BcPDE was found to be a potent mammary tumorigen and carcinogen, inducing significantly more fibroadenomas and adenocarcinomas than the other two compounds. In a second bioassay, BcPDE, BgCDE, and DB[a,l]PDE at a total dose of 1.2 μmol were compared. All three diol epoxides were potent mammary carcinogens and based on the collective results to date, the relative carcinogenic activities of the diol epoxides can be approximated as DB[a,l]PDE>BcPDE>BgCDE>BPDE.

To determine tumorigenic potencies in newborn mice, BPDE was compared with BgCDE, DB[a,l]PDE, and BcPDE at a total dose of 25 nmol per mouse, administered on days 1, 7, and 15 of life. BgCDE and BcPDE had similar potency in inducing lung tumors. BgCDE induced more liver tumors in male mice than BcPDE. Both compounds were more tumorigenic than BPDE. DB[a,l]PDE was highly toxic at 25 nmol and all animals died within one week after the first dose. DB[a,l]PDE was also tested at total intended doses of 5 nmol and 1 nmol. Due to high toxicity, only the first dose of the intended 5 nmol was given. This dose as well as the 1 nmol total dose caused significant incidence and multiplicity of lung tumors.

These results support the hypothesis that sterically hindered fjord region diol epoxides are potent mammary carcinogens in CD rats and strong lung tumorigens in newborn mice.