气相色谱串联质谱法测定饮用水中多种农药及其代谢产物残留

Determination of pesticides and metabolites residues in drinking water by LLE-GC-MS/MS

目的建立液液萃取-气相色谱串联质谱(Liquid liquid extraction and gas chromatography-tandem mass spectrometry,LLE-GC-MS/MS)测定饮用水中28种农药残留和代谢产物的检测方法。方法水样用二氯甲烷:正己烷(1∶1,V/V)溶剂提取后,合并提取液用氮气浓缩至1 ml,采用气相色谱串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)的多反应监测模式(multi reaction monitoring,MRM)对多种农药及其代谢产物残留同时定性定量分析,采用DB-5MS色谱柱(30 m×0.25 mm,0.25μm)分离。结果 28种农药在0.1~4.0 mg/L线性范围内均呈较好的线性关系,r>0.998。该方法的检出限为0.018~0.066μg/L。在1.6μg/L和4.0μg/L两种浓度添加水平,其平均回收率为85.3%~101.8%,相对标准偏差(relative standard deviations,RSD)为3.8%~9.2%。结论该方法快速、简单、准确,适用于同时检测饮用水中多种农药残留和代谢产物残留。

Objective To establish a method for the determination of 28 pesticides and metabolites residues in drinking water by Liquid extraction and gas chromatography-tandem mass spectrometry（ LLE-GC-MS/MS）. Methods The water samples were extracted with dichloromethane-hexane（ 1∶ 1,V/V） and the extract was evaporated by nitrogen into 1. 00 ml. The 28 pesticides and metabolites residues were qualitative and quantitative analysis by gas chromatography-tandem mass spectrometry in multi reaction monitoring mode（ MRM） and separated by DB-5 MS（ 30 m × 0. 25 mm,0. 25 μm） column. Results The regression coefficients（ r） of 28 pesticides were higher than 0. 998 and the limits of quantification（ LOD） was 0. 018 ～ 0. 066 μg/L. At the 1. 6μg/L,4. 0 μg/L spiked level,the mean recoveries ranged from 85. 3% to 101. 8%,and the relative standard deviations（ RSDs） ranged from 3. 8% to 9. 2%. Conclusion This method is fast,simple,high accuracy and has been used for the determination of 28 pesticides and metabolites residues in water samples.