Gas Chromatographic-Mass Spectrometric Analysis of Polycyclic Aromatic Hydrocarbon Metabolites in Antarctic Fish (Notothenia gibberifrons) Injected with Diesel Fuel Arctic

Fish (Notothenia gibberifrons) collected in pristine Antarctic sites were injected with Diesel Fuel Arctic (DFA). Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify polycyclic aromatic hydrocarbon (PAH) metabolites obtained from hydrolyzed fish bile. The concentrations of naphthols (NPH), phenanthrenols (PHN), dibenzothiophenols (DBT), and total PAH metabolites (EPAH) vary with time. The response curve (production of PAH metabolites vs. time) resembled a Sigmoid curve, with an initial low response at 24 h followed by a rapid rise in production of PAH metabolites (55.74 p,g/g) 120 h after exposure to DFA. PAH metabolites identified include NPH, PHN, and DBT and their alkylated derivatives, reflecting the composition of the DFA to which the fish were exposed. The GC/MS technique is highly sensitive, particularly in the detection of multi-ring PAH metabolites. The results suggest that analysis of PAH metabolites is a valuable tool for environmental monitoring and assessment of exposure to petroleum. Virtually all organisms possess biotransformation or detoxication enzymes which convert lipophilic xenobiotics to watersoluble and excretable metabolites (Livingston 1993). In the metabolic process, PAH are altered by phase I metabolism into various products such as epoxides, phenols, quinones, dihydrodiols, dihydrodiol epoxides, tetrahydrotriols, and tetrahydrotetrols (e.g., Varanasi and Gmur 1980). In phase II metabolism, these products are converted into highly water-soluble conjugates with a large water-soluble moiety, such as the tripeptide glutathione or sugar derivative glucuronic acid (Hellou and Payne 1978). The composition and concentrations of PAH metabolites in fish bile would thus be expected to indicate the extent of PAH exposure and the degree of exposure of fish to PAH (Krahn et al. 1992). Diesel Fuel Arctic (DFA) is a refined oil that contains semivolatile aromatic hydrocarbons such as naphthalenes and fluorenes (Kennicutt et al. 1991). In this study, DFA was administered by intramuscular (i.m.) injection to Antarctic fish (Notothenia gibberifrons). Biliary PAH metabolites were identified and quantified by gas chromatography/mass spectrometery techniques (Yu 1994). The objective of this study was to determine if the analysis of bile metabolites can be used as a reliable tool for monitoring and assessment studies of petroleum hydrocarbon contamination. Materials and Methods