DETERMINATION OF POLYCHLORINATED-BIPHENYLS IN BIOTIC MATRICES USING GAS-CHROMATOGRAPHY MICROWAVE-INDUCED PLASMA-ATOMIC EMISSION-SPECTROMETRY

Basic parameters associated with practical application of gas chromato graphy coupled with microwave-induced plasma atomic emission spectrome tric detection GC-MIP-AED in the determination of seven ''indicator'' polychlorinated biphenyls (PCBs) in biotic matrices were evaluated. Th e detection limit for chlorine (Cl-479) was ound to be 0.54 pg/s. Unde r the conditions used for sample analysis (1 mu l of purified extract injected into the GC-MIP-AED system represented 2.5 mg of original fat ), this value corresponded approximately to 0.15 mg/kg of the respecti ve congeners in fat. The detector response was linear within the teste d range of 0.5-10 ng of each injected PCB. The relative standard devia tion of repeated injections for the lowest concentration level of 0.5 ng of PCB per injection ranged between 10.5 and 34.4% depending on the chlorine content of the individual analytes. The results demonstrate a high selectivity of chlorine detection. Carbon (C-496) chromatograms recorded simultaneously demonstrated the efficiency of the clean-up s tep used. Quantitative results (analytes at levels of 0.1-1 mg/kg) obt ained with the atomic emission detector did not differ significantly f rom those recorded with a conventional electron-capture detector.