Determination of polychlorinated biphenyl congeners in environmental samples

A modified separation method has been developed for determinating polychlorinated biphenyl congeners in environmental samples. Direct treatment of extract with concentrated HzSO4 was employed in the first step for removal of lipids and other interfering substances, then a joint column of alumina-silica gel(Ag ) was applied to separate PCBs fraction from HCH, DDT and its analogs. After this separation, the PCBs fraction was analyzed by capillary gas chromatography with ECD detector and confirmed by GC/MS. The recoveries of individual congeners in Aroclor 1254 through the separation are about 79%-84%. The method is very efficient and useful for determination of trace amount of PCB congeners in environmental samples.