Validation and applications of a GC-ECD method for the determination of polychlorinated biphenyls in fish and seafood

This work illustrates how a well-optimized gas chromatograph-electron capture detector method represents an economical and satisfactory analytical choice for the routine determination of polychlorinated biphenyls (PCBs) of US Environmental Protection Agency concern in fish and seafood. A dramatic and never observed dependence of the recovery efficiency of PCB congeners on the temperature of activation of the sorbent phase prompted us to optimize both the key steps (extraction and cleanup) of the analytical procedure. Very high performance levels in terms of the limit of detection (less than 0.64 ng g(-1)) and precision [better than 15 % for unspiked and spiked samples of gilt-head bream, Sparus aurata, and better than 20 % for certified reference material BCR 350 (mackerel oil)] were obtained. The acceptability of accuracy data was successfully evaluated according to the Association of Official Analytical Chemists' guidelines. The method was tested by analyzing ten samples of aquacultured gilt-head bream from Greece and Italy. The total of 18 PCBs measured for each sample ranged from 120.1 to 335.5 ng g(-1) (average value 180.7 ng g(-1)) on a fat weight basis.