Detection of Benzo[a]Pyrene Metabolites by Laser-Excited Shpol'skii Spectrometry

Chemical carcinogenesis studies mandate isomer-selective detection at ultratrace levels of the metabolites of polycyclic aromatic compounds (PACs). The formation of hydroxy PACs is a key step in the metabolic process, particularly detoxification, for PACs in mammals. The infamous carcinogen benzo[a]pyrene (B[a]P) and its metabolites are often used as marker compounds to assess human exposure to total PACs and to study the development of cancer. In this work, isomers related to two alternative metabolic pathways for B[a]P have been selectively detected from urine and blood sera samples by laser-excited Shpol'skii spectrometry (LESS). The polar metabolites are derivatized and extracted into the n-alkane Shpol'skii solvent for direct, trace-level, isomer-selective detection. An absolute detection limit for 9-methoxy B[a]P was 50 attomole for a 20-μL sample.