液液萃取-程序升温大体积进样-气相色谱串联质谱法测定地表水中25种痕量有机氯农药

Trace analysis of 25 organochlorine pesticides in surface water by liquid liquid extraction-programmed temperature vaponization and large volume injection-gas chromatography tandem mass spectrometry

建立了液液萃取-程序升温大体积进样-气相色谱-串联质谱分析地表水中25种有机氯农药(OCPs)的方法。样品由正己烷溶液萃取氮吹仪浓缩后,经HP-5 ms色谱柱分离,在柱流速1.2 mL/min条件下电子轰击电离源多反应监测(MRM)模式进行检测,内标法定量。结果表明,取样量为250 mL时,25种OCPs方法检出限范围为0.32~1.34 ng/L,校准曲线的相关系数范围在0.9990~0.9999之间,各组份质量浓度在0~50.0μg/L线性范围内线性良好。低中高3组加标实际样品25种OCPs和2种替代物测定结果的相对标准偏差为3.5%~13%,加标回收率为74.0%~103%。方法能够满足地表水中有机氯的检测要求。

A method was established to determine 25 organochlorine pesticides in surface water by liquid liquid extraction-programmed temperature vaponization and large volume injection-gas chromatography tandem mass spectrometry.The samples were extracted by n-hexane solution,concentrated with nitrogen blowing apparatus,separated with HP-5 ms(60 m×0.25 mm×0.25μm)chromatographic column,and detected in multireaction monitoring(MRM)model and electron bombardment ionization conditions at a flow rate of 1.2 m L/min.The quantitation was performed by the internal standard method.The analysis results showed that the detection limits of 25 target compounds were in the rang of 0.32-1.34 ng/L when using 250 m L samples.The calibration curves showed good linearity for acrylonitrile(r>0.9990)in the linear range of 0-50.0μg/L.At three different concentration levels,the average recoveries of 25 target compounds and 2 substitutes in spiked practical samples were in the range of 74.0%-103% with relative standard deviations of 3.5%-13%.The modified method could monitor organochlorine pesticides in surface water.