Development of an analytical procedure using 1-nitropyrene metabolites as urinary biomarkers of exposure to diesel particulate matter

Abstract

Diesel exhaust particulate matter (DPM) is a major contributor to air pollution and has been recently classified as a group 1 human carcinogen. The combustion of diesel produces a variety of compounds including polycyclic aromatic hydrocarbons (PAHs) and nitrated polycyclic aromatic hydrocarbons (NPAHs). Considerable research has examined the effects of PAHs and NPAHs on human health. This research is limited by the lack of reliable biomarkers of exposure. Biomarkers of exposure allow for the accurate quantification of internalized xenobiotics. The current study demonstrates a highly sensitive analytical method for the quantification of urinary metabolites of 1-nitropyrene (1-NP), the most abundant NPAH present in DPM mixtures. Using liquid chromatography with tandem mass spectrometry (LC-MS/MS), the hydroxyl-1-nitropyrene metabolites (3-, 6-, and 8-OHNP) and hydroxyl-N-acetyl-1-aminopyrene metabolites (3-, 6-, and 8-OHNAAP) were synthesized and identified based on retention times and MS/MS spectra. The results of this study provide a sensitive measure of individual exposure to DPM which will facilitate future exposure assessment studies in vulnerable and susceptible study populations.