Diol Sep-Pak cartridges for enrichment of polychlorobiphenyls and chlorinated pesticides from water samples; Determination by GC-ECD

Gas chromatography of polychlorinated biphenyls and chlorinated pesticides in water samples has been performed after adsorption from a 20 - 200-mL sample on to a cartridge containing 100 mg diol-bonded porous silica. The PCBs are desorbed with 500 mu l ethyl acetate, which is concentrated and analysed by gas chromatography with electron-capture detection (GC-ECD). The average recovery of 0.1 ng mL(-1) PCB congeners from distilled water and from Aniene river water is greater than or equal to 95% (standard deviation less than or equal to 2.8). Average recoveries of 25 ng mL(-1) Aroclor 1254 from distilled water and from Aniene river water were, respectively 94.4% and 92.5% (standard deviation 5.8). In the separation of PCB congeners from the chlorinated pesticides only the aldrin (40%) was eluted with the PCBs from the diet Sep-Pak cartridge by aqueous methanol. The method described is simple and reproducible.