DETERMINATION OF PCBS IN FISH-TISSUES USING SUPERCRITICAL-FLUID EXTRACTION

Methods in common use for the determination of PCBs in fish are time-c onsuming, expose workers to toxic solvents, and generate significant v olumes of hazardous wastes. Supercritical fluid extraction (SFE), with CO:! and solid-phase cryogenic trapping, was applied to the analysis of PCBs in lyophilized fish tissues. Method evaluations were conducted using standard amended tissues and by comparison of SFE results to th ose obtained from conventional extraction procedures performed intra- and extramurally on fish with field-incurred PCBs. Good results fora r ange of PCBs were obtained after optimization of SFE conditions. Extra ction required only 40 min per sample and could be automated. Extracts were collected directly in GC autosampler vials. Addition of alumina to the extraction vessel eliminated the need for offline extract purif ication, despite the high lipid content of the tissues. Organic solven t usage was limited to 2 mL, in contrast to conventional procedures wh ich require several orders of magnitude more solvent.