Analysis of 27 polycyclic aromatic hydrocarbons by matrix solid-phase dispersion and isotope dilution gas chromatography-mass spectrometry in sewage sludge from the Spanish area of Madrid

A method for the determination of 27 polycyclic aromatic hydrocarbons (PAHs) in sludge from wastewater treatment plants (WWTPs) located in urban, industrial or rural zones is presented. PAHs were extracted by matrix solid-phase dispersion (MSPD) assisted by sonication. Purification of extracts was carried out by solid-phase extraction with C(18) and PAHs were eluted with acetonitrile. PAHs were determined by isotope dilution gas chromatography with electron impact mass spectrometric detection in the selected ion-monitoring mode (GC-MS-SIM), using deuterated PAHs as internal standards. The limits of detection ranged from 0.03 ng/g for acenaphthylene to 0.45 ng/g for benzo[b]naphtho[2,1-d]thyophene. After optimization, the method was validated with a certified reference sludge. The proposed analytical method was applied to determine PAH levels in sewage sludge samples collected from 19 water treatment plants located in the province of Madrid (Spain). In most of the examined samples, phenanthrene was the main compound with a mean concentration of 1062 ng/g. PAHs were detected in all of the samples, with total concentrations between 390 and 6390 ng/g dry weight for the 27 PAHs analyzed and from 310 to 5120 ng/g dry weight for the sum of the 10 PAHs considered in the draft European Union directive.     

Simultaneous liquid chromatographic determination of 39 polycyclic aromatic hydrocarbons in indoor and outdoor air and application to a survey on indoor air pollution in Fuji, Japan

An analytical method was established for the simultaneous determination of 39 polycyclic aromatic hydrocarbons (PAHs) in air. The method was applied to a survey of gaseous and particulate PAHs in household indoor air. The survey was performed in 21 houses in the summer of 1999 and in 20 houses in the winter of 1999-2000 in Fuji, Japan. Thirty-eight PAHs were determined in indoor and outdoor air in the summer, and 39 PAHs were determined in indoor and outdoor air in the winter. The concentrations of gaseous PAHs in indoor air tended to be higher than those in outdoor air in the summer and winter. The concentrations of particulate PAHs in indoor air were the same as or lower than those in outdoor air in the summer and winter. PAH profiles, correlations between PAH concentrations, and multiple regression analysis were used to determine the factors affecting the indoor PAH concentrations. These results showed that gaseous PAHs in indoor air were primarily from indoor emission sources, especially during the summer, and that indoor particulate PAH concentrations were significantly influenced by outdoor air pollution.     

Comparison of immunoassay and gas chromatography-mass spectrometry for measurement of polycyclic aromatic hydrocarbons in contaminated soil

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 sites. The ELISA was a carcinogenic PAH (C-PAH) RaPID assay testing kit that cross-reacts with several PAHs and utilizes benzo[a]pyrene (BaP) as a calibrator. Soil samples were extracted with 50% acetone in dichloromethane (DCM) for analysis by ELISA and gas chromatography-mass spectrometry (GC-MS). The overall method precision was within ±30% for ELISA and within ±20% for GC-MS. Recovery data for spiked soils ranged from 46 to 140% for BaP as determined by ELISA. Recoveries data of the GC-MS surrogate standards, 2-fluorobiphenyl and chrysene, were greater than 70%. The GC-MS procedure detected a total of 19 priority PAHs (2-6-ring PAHs) including seven probable human carcinogens (4-6-ring B2-PAHs). The ELISA results were compared to GC-MS summation results for the total 19 target PAHs as well as for the subset of the seven B2-PAH compounds. For all soil samples, the PAH concentrations derived from ELISA were greater than the sum of B2-PAH concentrations obtained by GC-MS. ELISA determinations were also frequently greater than the results obtained by GC-MS for the total 19 PAH compounds. This discrepancy can be expected, since the ELISA is a screening assay for the detection of several related PAHs while the GC-MS procedure detects priority PAH compounds. Thus, only a subset of PAHs (e.g. 19 PAHs) in the soil samples were measured by GC-MS while additional PAHs, including alkylated PAHs, and PAH derivatives have been demonstrated to be cross-reactive in the C-PAH ELISA. Results of paired tests show that the PAH data from ELISA and GC-MS methods are significantly different (P<0.001), but highly correlated. The ELISA data had a strong positive relationship with the GC-MS summation data for the B2-PAHs as well as for the 19 PAHs targeted by the GC-MS method. Results indicate that the ELISA may be useful as a broad screen for monitoring PAHs in environmental samples.     

Validation of the analysis of the 15+1 European-priority polycyclic aromatic hydrocarbons by donnor-acceptor complex chromatography and high-performance liquid chromatography-ultraviolet/fluorescence detection

The European Commission recommends to monitor the 16 polycyclic aromatic hydrocarbons (PAHs) possessing both genotoxic and carcinogenic properties. Since robust analytical methods specific for this set of European PAH are lacking, a new method for their analysis in food is proposed. The donnor-acceptor complex chromatography (DACC) is used as clean-up step and high-performance liquid chromatography-ultraviolet/fluorescence detection (HPLC-UV/FLD) is used for detection and quantification. The method has been validated for analysis of PAH in oil and in dried plants and bears very good results for all compounds.     

Identification, characterization and quantitation of pyrogenic polycylic aromatic hydrocarbons and other organic compounds in tire fire products

On 15 August 2001, a tire fire took place at the Pneu Lavoie Facility in Gatineau, Quebec, in which 4000 to 6000 new and recycled tires were stored along with other potentially hazardous materials. Comprehensive gas chromatography-mass spectrometry (GC-MS) analyses were performed on the tire fire samples to facilitate detailed chemical composition characterization of toxic polycyclic aromatic hydrocarbons (PAHs) and other organic compounds in samples. It is found that significant amounts of PAHs, particularly the high-ring-number PAHs, were generated during the fire. In total, 165 PAH compounds including 13 isomers of molecular weight (MW) 302, 10 isomers of MW 278, 10 isomers of MW 276, 7 isomers of MW 252, 7 isomers of MW 228, and 8 isomers of MW 216 PAHs were positively identified in the tire fire wipe samples for the first time. Numerous S-, O-, and N-containing PAH compounds were also detected. The identification and characterization of the PAH isomers was mainly based on: (1) a positive match of mass spectral data of the PAH isomers with the NIST authentic mass spectra database; (2) a positive match of the GC retention indices (I) of PAHs with authentic standards and with those reported in the literature; (3) agreement of the PAH elution order with the NIST (US National Institute of Standards and Technology) Standard Reference Material 1597 for complex mixture of PAHs from coal tar; (4) a positive match of the distribution patterns of PAH isomers in the SIM mode between the tire fire samples and the NIST Standard Reference Materials and well-characterized reference oils. Quantitation of target PAHs was done on the GC-MS in the selected ion monitoring (SIM) mode using the internal standard method. The relative response factors (RRF) for target PAHs were obtained from analyses of authentic PAH standard compounds. Alkylated PAH homologues were quantitated using straight baseline integration of each level of alkylation.     

Determination of Polycyclic Aromatic Hydrocarbons in Mangrove Sediments: Comparison of Two Internal Standard Surrogate Methods and Quality-Control Procedures

Two internal standard surrogate (ISS) methods, ISS-I (with m-terphenyl as a single ISS) and ISS-2 (using five deuterated PAHs as a multi-ISS), for the determination of polycyclic aromatic hydrocarbons (PAHs) in mangrove sediments were compared. The recovery percentages of 16 PAHs except naphthalene in HS-6 (a certified reference material) were high, ranging from 69.3 to 111.8% for ISS-1 and from 71.8 to 120.3% for the ISS-2 method. Similarly, the PAH recovery percentages in spiked mangrove sediments and clean sand were lower for ISS-I than for ISS-2, but both methods met the accurate acceptance criteria for PAH recoveries. The reproducibility (i.e. the method precision) between the two ISS methods was also comparable and satisfactory, with relative standard deviation values in most cases within 20% of the data variability. These results indicate that both ISS methods were acceptable for the determination of PAHs in mangrove sediments, despite the fact that the matrix of mangrove sediments may interfere with the PAH recovery efficiency.     

Differentiation of isomeric polyaromatic hydrocarbons by electrospray Ag(I) cationization mass spectrometry

Abundant Ag(I)-cationized complexes of 13 polyaromatic hydrocarbons (PAHs), [Ag+PAH](+) and [Ag+2(PAH)](+), were readily generated by electrospray ionization (ESI). In-source collision-induced dissociation (CID) of the [Ag+2(PAH)](+) complex yielded the monomer complex [Ag+PAH](+), which fragmented further to yield the radical molecular ion [PAH](+.). Based on significant differences in relative intensities of [Ag+2(PAH)](+), [Ag+PAH](+) and [PAH](+.), isomeric PAHs can be differentiated. The [PAH](+.)/[Ag+PAH](+) ion intensity ratio was found to increase with decreasing ionization potentials (IPs) of PAHs. The ratio was significantly different for the isomeric PAHs studied over a wide range of PAH concentrations (1.6-100 nmol/mL), and showed good measurement reproducibility; the coefficient of variation of inter-day measurements was in the range 3-12% for four representative PAHs (n = 5). Detection limits for phenanthrene, pyrene, chrysene and benzo[a]pyrene, in the form of the monomer complexes [(107)Ag+PAH](+) and measured in the selected-ion monitoring (SIM) mode, were 0.31, 0.63, 0.16 and 1.25 pmol/5 microl injection, respectively (S/N ratio approximately 2-3).     

Analysis of alkyl and 2-6-ringed polycyclic aromatic hydrocarbons by isotope dilution gas chromatography/mass spectrometry. Quality assurance and determination in Spanish river sediments

An accurate, precise and sensitive method is described for the analysis of 29 polycyclic aromatic hydrocarbons (PAHs), including 19 2-6-ringed PAHs and 10 alkyl-PAHs. The method is based on an isotope dilution technique using gas chromatography/mass spectrometry (GC/MS) and available labeled PAHs as internal standards. Quality parameters were calculated with satisfactory results and 36 Spanish river sediments were analysed. Results were evaluated regarding to the sediment quality guidelines (SQGs) based on the effects range-low (ERL) and the effects range-median (ERM) values. Most analysed sediments showed a good quality, since only 7 of them exceeded ERL values, including one sample surpassing ERM values. PAH profiles were studied in order to identify PAH sources as mainly petrogenic or pyrogenic. Most samples showed petrogenic-type fingerprints, although 6 of the 11 sediments with the highest PAH concentrations (> 1000 ng/g) were classified as pyrogenic, including 4 of the 7 samples exceeding ERL values. Quality assurance was carried out by the triplicate analysis of one preanalysed river sediment without PAHs subsequently spiked at a medium (500 ng/g) and a low concentration level (10 ng/g) of each analyte. Main quality requirements for methods based on isotope dilution were accomplished. Method accuracy was 80-120% for most PAHs, method precision was <15% for all the analysed compounds and method detection limits (MDLs) were 1-3 ng/g.     

Quantitative immunoassay for determining polyaromatic hydrocarbons in electrical insulating oils

The development and application of a combined sample extraction and immunoassay protocol for the quantification of polyaromatic hydrocarbons (PAHs) in transformer oils is reported. Tests were performed on 12 different used transformer oils from three major manufacturers. The removal of matrix interferents was achieved by loading oil fractions onto silica solid phase extraction cartridges and eluting with non-polar solvent prior to evaporation and reconstitution in a more polar medium. Extracts were immunoassayed using two commercially available PAH test kits either having broad specificity towards priority PAHs or enhanced binding specificity toward more carcinogenic PAHs. The total and carcinogenic PAH test kits yielded PAH levels in the oil extracts 5.86-fold and 126-fold lower than the industry-standard IP346 method. The latter method, widely used by the industry, since it correlates with biological carcinogenicity tests, grossly over-estimates PAH levels in oils since it is a non-specific gravimetric solvent extraction approach. The assay was found to be unaffected by the extract sample matrix and was capable of determining PAHs at the nanogram per millilitre level. The assay protocol was simple, low-cost and rapid (<2 h) and equally amenable to operation at remote sites or high-throughput sample screening. The binding specificity of the total anti-PAH antibody was examined by preparing and loading an anti-PAH immunosorbent with oil, prior to solvent displacement of antibody-bound compounds and by gas chromatography (GC)–mass spectrometry (MS) analysis.     

Rapid method for the determination of polycyclic aromatic hydrocarbons in agricultural soils by sonication-assisted extraction in small columns

A rapid method has been developed for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in soil based on their sonication-assisted extraction in small columns (SAESC) with a low volume of ethyl acetate and subsequent quantitation and identification by GC with electron impact mass spectrometric detection in the SIM mode (GC-MS-SIM). Spiked blank soil extracts were used as standards to counteract the matrix effect observed in the chromatographic determination. PAHs were confirmed at trace level by their retention times, their qualifier and target ions, and their qualifier/target abundance ratios. Recovery studies were performed at 0.5, 1.0, 5.0, and 10 microg/kg fortification levels for each PAH, and the recoveries obtained ranged from 91.2 to 99.8% with RSDs between 0.4 and 9.3%. The detection limits of the method ranged from 0.03 to 0.3 microg/kg for the different PAHs studied. The developed method is linear over the range assayed, 1-100 microg/L with determination coefficients higher than 0.996. PAH levels were determined using this method in soil samples taken from different agricultural areas of Spain. In general, PAH concentrations were low and the most frequently occurring PAHs were naphthalene, pyrene, phenanthrene, and fluoranthene.     

Analysis of EU priority polycyclic aromatic hydrocarbons in food supplements using high performance liquid chromatography coupled to an ultraviolet, diode array or fluorescence detector

High performance liquid chromatography coupled to an ultraviolet, diode array or fluorescence detector (HPLC/UV-FLD) has been used to set up a method to detect the 15(+1) EU priority polycyclic aromatic hydrocarbons (PAHs) in food supplements covering the categories of dried plants and plant extracts excluding oily products. A mini validation was performed and the following parameters have been determined: limit of detection, limit of quantification, precision, recovery and linearity. They were in close agreement with quality criteria described in the Commission Regulation (EC) No 333/2007 concerning the PAH benzo[a]pyrene in foodstuffs, except the not fluorescent cyclopenta[c,d]pyrene for which the UV detection leads to a higher limit of detection. Analysis of twenty commercial food supplements covering mainly the class of dried plants was performed to evaluate their PAHs contamination levels and to test the applicability of the method to various plant matrices. Fifty percent of analyzed samples showed concentration exceeding 2 μg kg⁻¹ for one or more PAHs.     

Determination of trace PAHs in seawater and sediment pore-water by solid-phase microextraction (SPME) coupled with GC/MS

A fast and reliable method for the determination of trace PAHs (polynuclear aromatic hydrocarbons) in seawater by solid-phase microextraction (SPME) followed by gas chromatographic (GC) analysis has been developed. The SPME operational parameters have been optimized, and the effects of salinity and dissolved organic matter (DOM) on PAHs recoveries have been investigated. SPME measures only the portion of PAHs which are water soluble, and can be used to quantify PAH partition coefficient between water and DOM phases. The detection limits of the overall method for the measurement of sixteen PAHs range from 0.1 to 3.5 ng/g, and the precisions of individual PAH measurements range from 4% to 23% RSD. The average recovery for PAHs is 88.2±20.4%. The method has been applied to the determination of PAHs in seawater and sediment porewater samples collected in Jiaozhou Bay and Laizhou Bay in Shandong Peninsula, China. The overall levels of PAHs in these samples reflect moderate pollution compared to seawater samples reported elsewhere. The PAH distribution pattern shows that the soluble PAHs in seawater and porewater samples are dominated by naphthalenes and 3 ring PAHs. This is in direct contrast to those of the sediment samples reported earlier, in which both light and heavy PAHs are present at comparable concentrations. The absence of heavy PAHs in soluble forms (<0.1-3.5 ng/L) is indicative of the strong binding of these PAHs to the dissolved or solid matters and their low seawater solubility.     

Polyurethane foam chips combined with liquid chromatography in the determination of unmetabolized polycyclic aromatic hydrocarbons excreted in human urine

A method suitable for the determination of unmetabolized polycyclic aromatic hydrocarbons (PAHs) excreted at trace levels (ng/L) in human urine for the monitoring of exposure of the general population to PAH contamination was developed. PAHs were determined, after enrichment by solid-phase extraction on polyurethane foam (PUF) chips, by HPLC with fluorescence detection. Different parameters affecting analyte extraction to the PUF, including urine salting-out and organic additives, and optimization of conditions for clean-up and desorption have been investigated. Optimized conditions were 40 mL acidified urine sample, added with magnesium sulfate, tetrahydrofuran and a 2 cm3 PUF chip, and extracted by shaking at 30 rpm for 1 h at ambient temperature. Desorption was performed, after a clean-up step with diluted sodium hydroxide, using a small amount of diethyl ether. The recovery of PAH congeners from spiked urines was >90% in the 2-100 ng/L range; the detection limit was 0.1-0.5 ng/L, depending on the considered PAH congener; day-to-day precision, at 50 ng/L native PAH content, was CV = 10-20%. The proposed technique provides a simple, economical and effective procedure for the determination of trace amounts of unmetabolized PAHs excreted in human urine spot samples.     

Screening and determination of polycyclic aromatic hydrocarbons in seafoods using QuEChERS-based extraction and high-performance liquid chromatography with fluorescence detection

A rapid, sensitive, and accurate method for the screening and determination of polycyclic aromatic hydrocarbons (PAHs) in edible seafood is described. The method uses quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based extraction and HPLC with fluorescence detection (FLD). The method was developed and validated in response to the massive Deepwater Horizon oil spill in the Gulf of Mexico. Rapid and highly sensitive PAH screening methods are critical tools needed for oil spill response; they help to assess when seafood is safe for harvesting and consumption. Sample preparation involves SPE of edible seafood portions with acetonitrile, followed by the addition of salts to induce water partitioning. After centrifugation, a portion of the acetonitrile layer is filtered prior to analysis via HPLC-FLD. The chromatographic method uses a polymeric C18 stationary phase designed for PAH analysis with gradient elution, and it resolves 15 U.S. Environmental Protection Agency priority parent PAHs in fewer than 20 min. The procedure was validated in three laboratories for the parent PAHs using spike recovery experiments at PAH fortification levels ranging from 25 to 10 000 microg/kg in oysters, shrimp, crab, and finfish, with recoveries ranging from 78 to 99%. Additional validation was conducted for a series of alkylated homologs of naphthalene, dibenzothiophene, and phenanthrene, with recoveries ranging from 87 to 128%. Method accuracy was further assessed based on analysis of National Institute of Standards and Technology Standard Reference Material 1974b. The method provides method detection limits in the sub to low ppb (microg/kg) range, and practical LOQs in the low ppb (microg/kg) range for most of the PAH compounds studied.     

DNA Nanogels To Snare Carcinogens: A Bioinspired Generic Approach with High Efficiency

Polycyclic aromatic hydrocarbons (PAHs) are combustion‐related pollutants and are ubiquitous in the environment, including in sources of drinking water. Upon contact with DNA, stable PAH–DNA adducts form rapidly as the first step towards their toxic effects. In this work, we prepared hydrophilic DNA nanogels to exploit this generic complexation process as a biomimetic scavenging method. This approach relies on interaction between PAHs and the complete network that constitutes the water‐swollen nanogels, and is not restricted to interfacial adsorption. Up to 720 μg of PAH per gram of DNA nanogel are taken up, meaning that 1 mg of DNA nanogel is sufficient to purify a liter of water containing the critical PAH concentration for cancer risk (600 ng L^?1). As a result of short diffusion pathways, PAH uptake is rapid, reaching 50 % loading after 15 minutes. Beyond PAHs, DNA nanogels may be useful for the generic detoxification of water containing genotoxins, since most known molecules that strongly associate with DNA are mutagenic.     

Development of an improved analytical method for the determination of carcinogenic polycyclic aromatic hydrocarbons in transformer oil

Polynuclear aromatic hydrocarbons (PAHs) are natural constituents of transformer oils and are essential in prolonging transformer in-service lifetime. Issues concerning PAH carcinogenicity demand methods that provide qualitative and quantitative information on the PAH composition of new and in-service oils to allow informed operational decisions to be made. However, current analytical methods focus on PAH fingerprinting, as opposed to quantitative analysis and are also cumbersome, relying on the use of large (>100 ml) volumes of organic solvents, some of which are hazardous. This paper reports a method for the improved quantification of carcinogenic PAHs in transformer oils that is both simple and repeatable. The method uses commercially available solid-phase extraction columns and millilitre volumes of relatively non-hazardous solvents. Extraction efficiencies of > or =74% were obtained for the Environmental Protection Agency priority PAHs. The method has potential for automation and high-throughput analysis and thus is of interest to industries that use transformer oils.     

Rapid and sensitive determination of polycyclic aromatic hydrocarbons in atmospheric particulates using fast high-performance liquid chromatography with on-line enrichment system

A method using on-line enrichment and fast high-performance liquid chromatography (HPLC) with fluorescence detection has been developed and validated for the determination of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate samples. The evaporation step for sample preparation can be eliminated since this system allows the injection of 1000microL of sample solution. PAH recoveries were between 87% and 120% for spiked atmospheric particulate samples. The limit of detection was 0.02-0.23ng/mL (signal/noise ratio=3.3). There was good linear correlation between HPLC peak area and PAH concentration, with a linear range of 0.4-40ng/mL and correlation coefficients >0.997. Furthermore, compared to conventional approaches that include an evaporation step, the method proposed is acceptable for detecting PAHs in atmospheric particulate samples.     

Static subcritical water extraction with simultaneous solid-phase extraction for determining polycyclic aromatic hydrocarbons on environmental solids

A rapid and very simple method for extracting polycyclic aromatic hydrocarbons (PAHs) from soils, sediments, and air particulate matter has been developed by coupling static subcritical water extraction with styrene-divinylbenzene (SDB-XC) extraction discs. Soil, water, and the SDB-XC disc are placed in a sealed extraction cell, heated to 250 degrees C for 15 to 60 min, cooled, and the PAHs recovered from the disc with acetone/methylene chloride. If the cells are mixed during heating, all PAHs with molecular weights from 128 to 276 are quantitatively (>90%) extracted and collected on the sorbent disc and are then recovered by shaking with acetone/methylene chloride. After water extraction, the sorbent discs can be stored in autosampler vials without loss of the PAHs, thus providing a convenient method of shipping PAH extracts from field sites to the analytical laboratory. The method gives good quantitative agreement with standard Soxhlet extraction, and with certified reference materials for PAH concentrations on soil, sediment (SRM 1944), and air particulate matter (SRM 1649a).     

Strategies for synthesis of adducts of omicron-quinone metabolites of carcinogenic polycyclic aromatic hydrocarbons with 2'-deoxyribonucleosides

Polycyclic aromatic hydrocarbons (PAHs) are major environmental carcinogens produced in the combustion of fossil fuels, tobacco, and other organic matter. Current evidence indicates that PAHs are transformed enzymatically to active metabolites that react with DNA to form adducts that result in mutations. Three activation pathways have been proposed: the diol epoxide path, the radical-cation path, and the quinone path. The latter involves aldo-keto reductase mediated oxidation of PAH dihydrodiol metabolites to catechols that enter into redox cycles with quinones. This results in generation of reactive oxygen species (ROS) that attack DNA, and the PAH quinones also react with DNA to form adducts. Several strategies for synthesis of the stable adducts formed by the o-quinone metabolites of carcinogenic PAHs with 2'-deoxyribonucleosides were investigated and compared. The PAH quinones studied were benz[a]anthracene-3,4-dione and its 7-methyl- and 7,12-dimethyl- derivatives. The parent PAHs represent a range of carcinogenicity from inactive to highly potent. Two synthetic methods were devised that differ in the catalyst employed, Pd(OAc)(2) or CuI. The Pd-mediated method involved coupling a protected amino-catechol PAH derivative with a halo-2'-deoxyribonucleoside. The copper-mediated method entailed reaction of a halo-PAH catechol derivative with a 2'-deoxyribonucleoside. Adducts of benz[a]anthracene-3,4-dione (and its 7-methyl- and 7,12-dimethyl- derivatives) with 2'-deoxyadenosine and 2'-deoxyguanosine were prepared by these methods. Availability of adducts of these types through synthesis makes possible for the first time biological studies to determine the role of these adducts in tumorigenesis. The copper-mediated method offers advantages of economy, adaptability to large-scale preparation, utility for synthesis of (13)C- or (15)N-labeled analogues, and nonformation of bis-adducts as secondary products.     

A Routine Method for the Quantitative Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Urban Air

Abstract

We have developed a method for the quantitative determination of polycyclic aromatic hydrocarbons (PAHs) present in urban air, which can be performed rather quickly, and which uses a minimal amount of solvents.

Air samples were collected using a home-made low-volume air sampler equipped with glass fibre filter and polyurethane foam plugs. After Soxhlet extraction a liquid-liquid partition was carried out to isolate the PAH fraction. This liquid-liquid partition was performed in micro-scale, enabling us to use small quantities of the solvents and to separate the solution layers very rapidly using a centrifuge. Sample clean-up was accomplished on a high performance liquid chromatograph equipped with two normal phase silica columns. The losses of all investigated PAHs occurring during the various steps of sample clean-up have been determined. The qualitative and quantitative determination of the PAHs was carried out by capillary gas chromatography; the results were confirmed by GC/MS measurements.

The analytical procedure described was applied over a period of one year to measure the concentrations of 21 PAHs in the city of Vienna at a site with high traffic density. The concentrations of the four more volatile PAHs were determined on a semi-quantitative basis. The ratio of two selected PAHs was used to estimate the respective contribution of traffic and domestic heating to the total PAH level at the sampling site.