An evaluation of two fluorescence screening methods for the determination of chrysene metabolites in fish bile

Two screening methods, synchronous fluorescence spectrometry (SFS) and high performance liquid chromatography with fluorescence detection (HPLC-F), have been evaluated for their suitability in determining chrysene metabolites in fish bile. The optimal wavelength pair, excitation/emission 272/374 nm, for SFS measurements of chrysene metabolites was identified by analysis of bile taken from fish exposed to the pure compound. This analysis revealed in addition some information about the metabolite pattern. However, when bile from fish exposed to complex and environmentally relevant mixtures of polycyclic aromatic hydrocarbons (PAHs) was analysed using these methods, identification of the chrysene metabolites was poor. Analysis of bile taken from fish exposed to single PAHs identified other three- and four-ring aromatics as the main interfering compounds. Both methods were equally able to discriminate between impacted and reference sites by determination of relative concentrations of fluorescent three- and four-ring aromatics.