CHEMICAL DERIVATIZATION AND SHPOLSKII SPECTROFLUOROMETRIC DETERMINATION OF BENZO[A]PYRENE METABOLITES IN FISH BILE

The practical applicability and analytical performance of laser-excited Shpol'skii spectroscopy (LESS) for the determination of benzo[a]pyrene (BaP) metabolites was studied. Quantitation of these compounds in fish bile can provide insight into the BaP uptake from a contaminated aquatic environment (biomonitoring). Chemical derivatization of hydroxylated BaP metabolites with methyl iodide (to improve the compatibility with the Shpol'skii matrix) was tested. The methylation of phenolic metabolites was rapid and quantitative, but with BaP-dihydro diol metabolites, mixtures of methylation and elimination products were formed. An analytical procedure was developed for the quantitative determination of 3-OH-BaP, the major BaP metabolite detected in bile from flounder (Platichthys flesus). With LESS, the detection limit was 0.005 ng/ML (200 amol); the repeatability was 16 %. The method was applied to a mesocosm experiments in which flounders were exposed to different sediments. The average BaP uptake from Rotterdam harbor sediment was 40 times higher than the uptake from Wadden Sea sand. Direct contact with the sediments was a major route of exposure. The usefulness of the method for the biomonitoring of polycyclic aromatic hydrocarbon stress in the aquatic environment is discussed.