提出了液液萃取富集-气质联用法测定饮用水中19种农药的残留量。样品用二氯甲烷萃取3次(20,10,10 mL),萃取液合并后旋转蒸发至1.0 mL,分取1.0 μL进样,进行气相色谱-质谱分析。用HP-5MS毛细管柱分离及电子轰击离子源,用离子检测扫描模式做质谱测定。用菲-d10作内标,峰面积定量。19种农药在一定浓度范围内呈线性,检出限(3S/N)为0.002~0.10 mg·L-1之间,回收率在81.1%~103.0%之间,相对标准偏差(n=6)为0.25%~7.7%。

GC-MS with enrichment by liquid-liquid extraction was applied to the determination of residual amounts of 19 pesticides in drinking water. The pesticides in sample were extracted thrice with dichloromethane (20, 10, 10 mL), the extracts were combined and evaporated rotationally to 1.0 mL, from which 1.0 μL was taken for GC-MS analysis. The HP-5MS capillary column was used for separation, and EI source with SIM mode was used in MS determination. Phenanthrene-d10 was added as internal standard, and values of peak area were used in quantification. Linearities for the 19 pesticides were obtained in definite concentration ranges, with values of detection limits (3S/N) ranged from 0.002 to 0.10 mg·L-1. Values of recovery found by standard addition method were in the range of 81.1%-103.0% with RSD′s (n=6) ranged from 0.25% to 7.7%.