Compound-specific gas chromatographic/mass spectrometric analysis of alkylated and parent polycyclic aromatic hydrocarbons in waters, sediments, and aquatic organisms

Polycyclic aromatic hydrocarbons (PAHs) and their alkylated and heterocyclic analogs are ubiquitous contaminants in aquatic environments, including estuaries and marine systems. Methodology for compound-specific analysis of 63 parent, alkylated, and heterocyclic PAHs using gas chromatography/mass spectrometry (GC/MS) in both scanning and selected-ion monitoring modes has been developed and applied to sediment, natural waters and effluents, and marine organisms including oysters, mussels, and fish. Relative response factors and relative retention times for the 63 alkylated, heterocyclic, and parent PAHs compared with 6 deuterated PAHs are given. Analyses of natural sea water samples, enriched at concentrations ranging from 5 to 100 ng/L, show good accuracy (8% mean difference at the 5 ng/L level) and precision (mean RSD of 9%), and method detection limits are in the parts-per-trillion range. Results for sediments and tissues of aquatic organisms exposed to petroleum contamination demonstrate that analysis of parent PAHs alone vastly underestimates levels in sediments and tissues and the potential toxic effects of such residues in food webs. Multiple analyses of a reference tissue material show good precision (mean RSD of 15%) and accuracy (mean difference of 17%) for both alkylated and parent PAHs.