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We developed a gas chromatography/isotope dilution high resolution mass spectrometry (GC/ID-HRMS) method for measuring 18 PAH metabolites representing 8 parent PAHs in 3 mL of urine at low part-per-trillion levels. We applied this method to the analysis of urine specimens from approximately 2400 people who participated in the National Health and Nutrition Examination Survey for the years 1999 and 2000 to determine levels for 14 PAH hydroxy metabolites of 7 parent compounds. Using this GC/ID-HRMS method, we found detectable concentrations for monohydroxy metabolite isomers of flourene, phenanthrene, fluoranthene, and pyrene, and for chrysene, benzo[c]phenanthrene, and benz[u]anthracene. Some mono-hydroxy metabolite isomers of chrysene. benzo[c]phenanthrene, and benz[a]anthracene exhibited low detection frequencies which did not allow for geometric mean calculations. From our study, we established a reference range for the targeted PAHs in the general U.S. population. [ABSTRACT FROM AUTHOR]

We developed a gas chromatography/isotope dilution high- resolution mass spectrometry (GC/ID-HRMS) method for measuring 18 PAH metabolites representing 8 parent PAHs in 3 mL of urine at low part-per-trillion levels. We applied this method to the analysis of urine specimens from approximately 2400 people who participated in the National Health and Nutrition Examination Survey for the years 1999 and 2000 to determine levels for 14 PAH hydroxy metabolites of 7 parent compounds. Using this GC/ID-HRMS method, we found detectable concentrations for monohydroxy metabolite isomers of fluorene, phenanthrene, fluoranthene, and pyrene, and for chrysene, benzo[c]phenanthrene, and benz[a]anthracene. Some monohydroxy metabolite isomers of chrysene, benzo[c]phenanthrene, and benz[a]anthracene exhibited low detection frequencies which did not allow for geometric mean calculations. From our study, we established a reference range for the targeted PAHs in the general U.S. population. [ABSTRACT FROM AUTHOR]

Sample preparation techniques using solid-phase extraction (SPE) and solid-phase microextraction (SPME) are compared for the analysis of monohydroxy polycyclic aromatic hydrocarbons (OHPAH) in human urine. Urine samples spiked with five carbon-13 labeled internal standards are first enzymatically hydrolyzed. Sixteen OHPAH from eight parent compounds (naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, benzo[ c ]phenanthrene, and benz[ a ]anthracene) are then extracted along with the internal standards by these two different techniques. The analytes are derivatized by a silylating reagent before final analysis. Final separation and detection are performed by temperature-programmed capillary gas chromatography (GC) and high-resolution mass spectrometry (HRMS). The two extraction techniques are compared for sample preparation time, cost, throughput, reinjection possibility, frequency of outliers, matrix interference, signal linearity, and method detection limit. SPE demonstrates major advantages over SPME for most of these aspects. [ABSTRACT FROM AUTHOR]

The foundation for a systematic approach utilizing spectral/structural correlations was established for unambiguous identification of monohydroxylated polyaromatic hydrocarbon metabolite (PAHm) isomers. Using elements of a theoretical/empirical valence-bond model developed earlier in our laboratory for isomer identification of chlorinated dibenzo- p -dioxin isomers, both gas chromatography/Fourier transform infrared spectroscopy (GC/FTIR) and carbon-13 nuclear magnetic resonance ( 13 C NMR) spectroscopy were employed for PAHm isomer identification. Results indicate that PAHm isomers also can be systematically identified by these techniques. However, many of the parameters leading to the success of the dioxin analysis (high symmetry of the parent dioxin molecule and laterally stabilized delocalization from chlorine substituents through ether linkage oxonium ions) are not generally present in the PAHm ring systems under investigation. The observed infrared parameters in PAH metabolites are C--O stretch, O--H stretching and bending vibrations, along with C=C skeletal stretching vibrations. In addition, 13 C NMR parameters such as chemical shift perturbations for carbons adjacent to functional groups have been observed. [ABSTRACT FROM AUTHOR]

For measurement of biomarkers from polycyclic aromatic hydrocarbon (PAH) exposure, an analytical method is described quantifying hydroxylated PAH (OH-PAH) in urine samples. This method determined monohydroxy metabolites of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, benzo[ c]phenanthrene, and benz[ a]anthracene. The sample preparation consisted of enzymatic hydrolysis, solid-phase extraction and derivatization with a silylating reagent. Five carbon-13 labeled standards were used for isotope dilution. Analytes were separated by gas chromatography (GC) and quantified with high-resolution mass spectrometry (HRMS). This method produced good recoveries (41–70%), linearity, and specificity. Data were corrected for blank levels from the naphthalene, fluorene, and phenanthrene metabolites. Method detection limits ranged from 2 ng L–1 for 1-hydroxypyrene to 43.5 ng L–1 for 1-hydroxynaphthalene. Using quality control charts from two urine pools, the method can be readily applied to biomonitoring PAH exposure. [ABSTRACT FROM AUTHOR]