Gas Chromatographic Determination of Polychlorinated Biphenyls in Drinking Water Samples with Solid Phase Extraction

A method for the determination of Polychlorinated Biphenyls (PCBs) in drinking water by gas chromatography was established. Determination parameters, such as elution curves, pH, effect of methanol, dosage of NaCl and flow rate are discussed and optimized in this paper. The method is compared to the classical liquid-liquid extraction method. By the new method, 84 PCBs were extracted from drinking water under pH=3 and flow rate of 5 mL/min by large volume sampler-solid phase extraction, eluted by 7 mL acetone and 5 mL acetonitrile. The eluate was concentrated and the solvent exchanged with hexane as 1.0 mL by nitrogen blowing, then an internal standard added. The target compounds were determined by gas chromatography with μ-electron capture detector, verified by mass spectrometry in the selected ion method, under the same conditions as chromatography. The detection limits of the method for 84 PCBs ranged from 1.2 to 15.0 ng/L, and the average recoveries ranged from 74.8% to 126.8% with relative standard deviation (RSD) of 1.1%-14.8%. This method can be applied to the routine analysis of PCBs in water samples and has the advantages of simultaneous extraction for multi samples, is a rapid process, and produces less pollution with more cost effectiveness.