Evidence for the importance of including hydrocarbon oxidation products in environmental assessment studies

Abstract

To provide evidence for the importance of including hydrocarbon oxidation products in environmental assessment studies, 10 samples of bivalve tissue from Prince William Sound, collected as part of the assessment of the 1989 Valdez Oil Spill were extracted and separated into fractions based on polarity, by normal phase high performance liquid chromatography (HPLC). Each fraction was analysed by ultraviolet fluorescence spectroscopy (UVF) and examined for evidence of the presence of oxidation products of aromatic hydrocarbons (O-PAHs). Fluorescence in the wavelengths characteristic of O-PAHs was present in the bivalve extracts and intensity correlated with the amount of petroleum hydrocarbons as determined by gas chromatography (GC). The percentage of UVF intensity in polar fractions compared to the hydrocarbon fractions ranged from 7–85% and corresponded with degree of weathering the oil residues had undergone as determined by their GC patterns. Thus, although UVF is only a semi-quantitative method, these results support the contention that photo and bacterial degradation processes create a complex assemblage of intermediate oxidation products of hydrocarbons that are bioaccumulated in marine organisms. Analytical methodologies applied to marine monitoring and hazard assessments must be extended to include some of the oxidation products formed from the toxicants spilled into the marine environment.