摘要:
研究了饮用水中84种多氯联苯的气相色谱分析方法。讨论了洗脱曲线、水样的pH值、甲醇加入量、含盐量、萃取流速等实验条件,并与经典的液-液萃取方法进行了对比。确定了样品在pH值为3,以5 mL/min的流速经大体积样品采样器-C18固相萃取柱富集,7 mL丙酮和5 mL乙腈洗脱,氮吹蒸发浓缩后正己烷定容至1.0 mL,加入内标后使用电子捕获检测器气相色谱仪测定,并在选定的色谱条件下以选择离子监测方式进行验证。84种多氯联苯的方法检出限为1.2~15.0 ng/L,加标回收率为74.8%~126.8%,相对标准偏差为1.1%~14.8%。由于采用了大体积样品采样器,可实现多个样品的同时萃取富集,方法快速、低污染,低成本,可用于批量水样品中多氯联苯的分析测定。
Abstract:
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.
下载: