固相膜萃取-气相色谱-串联质谱法测定饮用水中67种农药残留

目的建立同时测定饮用水中67种农药残留的固相膜萃取-气相色谱-串联质谱法。方法水样经C₁₈固相膜萃取,二氯甲烷和乙酸乙酯(7∶3,V/V))混合溶剂洗脱,40℃氮吹浓缩,采用DB-5MS毛细管气相色谱柱(30 m×0.25 mm×0.25μm)分离,多反应监测模式进行串联质谱检测,工作曲线法定量。结果本法除敌敌畏、速灭威部分农药外,线性范围为0.050～5μg/L,相关系数为0.9924～0.9999,方法定量限(S/N=10)为1.0×10^-5～0.059μg/L。通过3个浓度水平的加标实验测得方法回收率为81.0%～125.0%,相对标准偏差为1.5%～21.4%(n=6)。结论本法准确灵敏、操作简便、环保,适用于生活饮用水中多种农药残留的同时快速分析。

Determination of 67 pesticides in drinking water by solid phase extration disk extraction-gas chromatography-tandem mass spectrometry

OBJECTIVE To develop a method for the simuhaneous determination of 67 pesticides in water by solid phase extration (SPE)disk extraction-gas chromatography-tandem mass spectrometry (GC-MS/MS).METHODS Pesticides in water were extracted and cleaned-up with SPE disk,then eluted with dichloromethane-nethyl acetate(7 :3,V/V).After the eluent being concentrated to 1 mL under nitrogen blow at 40 ℃,the supernatant was injected into GC-MS/MS for analysis.The GC separation was performed on a DB-SMS capillary column(30 m×0.25 mm×0.25 μm).The pesticides were detected by MS/MS in muhiple reaction monitoring (MRM)mode and quantified by working curve method.RESULTS The linear range of the method for most of the pesticides were in the range of 0.05-5 μg/L with correlation coefficients of 0.9924 -0.9999.The quantitative limits(S/N=10)of the method were in the range of 1.0×10^-5 -0.059 μg/L.The recoveries for pesticides were 81.0%-125.0%with relative standard deviations of 1.5%-21.4%(n =6).CONCLUSION The method is sensitive,simple, environmentally friendly and suitable to the determination of pesticides in drinking water for rapid screening and quantitative analysis.