Formation of pyrene metabolites by the terrestrial isopod Porcellio scaber

The formation of pyrene metabolites by the temestrial isopod Porcellio scaber (Latr.) was studied following exposure for 13 days to 100 μg/g pyrene in its food. An alkaline hydrolysis method with subsequent liquid-liquid extraction was developed to determine the metabolite content, especially 1-hydroxypyrene. Synchronous Fluorescence Spectroscopy (SFS) was explored as a fast screening method and HPLC was applied as a complementary method for confirmation of the SFS results. In Porcelho scaber the amount of 1-hydroxypyrene exceeded that of pyrene, which indicates that pyrene is being metabolized extensively. SFS and HPLC demonstrated that Porcellio scaber also forms a number of other fluorescent metabolites. These metabolites exhibit fluorescence at the same excitation wavelength as 1-hydroxypyrene, possibly indicating a similar fluorophore structure. Determination of 1-hydroxypyrene is considered as a first step towards an improved environmental risk assessment of PAH exposure, as pyrene is a predominant member of this class of environmental contaminants and 1-hydroxypyrene is its major metabolite.