全自动固相萃取-凝胶净化-气相色谱-串联质谱检测耕地水渠中5种农药残留方法的建立

Establishment of automatic SPE-GPC-GC/MS/MS method for determination of 5 pesticides residues in farmland water

建立全自动固相萃取-凝胶净化-GC-MS/MS对耕地水渠中的5种农药残留(螺螨酯、肟菌酯、吡唑醚菌酯、2,4-滴丁酯和七氟菊酯)的检测方法。采用全自动固相萃取技术,选择ENVI-Carb固相萃取柱对耕地水样品进行农药提取。提取液经凝胶净化色谱净化后在氮吹仪中吹至近干。加入1 mL乙酸乙酯溶解残渣,0.22μm微孔滤膜过滤后进样气相色谱质谱联用仪(GC-MS/MS)以多反应监测模式(MRM)扫描,外标法定量。结果表明螺螨酯、肟菌酯、吡唑醚菌酯、2,4-滴丁酯和七氟菊酯在质量浓度0.01~2.0μg/mL范围内线性关系良好,线性相关系数均大于0.995,检出限如下:螺螨酯:4.23μg/L、肟菌酯:3.52μg/L、吡唑醚菌酯:3.69μg/L、2,4-滴丁酯:2.26μg/L、七氟菊酯:1.25μg/mL。样品在低、中、高三水平浓度点的回收率在90.9%~101.3%之间,精密度测定结果的相对标准偏差在1.68%~4.03%(n=6)。该方法净化效果好,定性定量结果准确,适用于水样中农药残留的监测。

To establish an automatic solid phase extraction(SPE)-gel purification chromatography(GPC)-gas chromatography-tandem mass spectrometry(GC-MS/MS)method for determination of 5 pesticides(spirodiclofen,trifloxystrobin,pyraclostrobin,2,4-butyl ester and tefluthrin)residues in farmland water.ENVI-Carb solid phase extraction column was selected to extract pesticides from cultivated water samples by automatic solid phase extraction technology.Extracting solution was purified by gel purification chromatography(GPC)and flowed to neardry by nitrogen.1 mL ethyl acetate was used to dissolve residue,filtered by 0.22μm microporous membrane,samples were detected on GC-MS/MS by multi-reaction monitoring mode(MRM),and quantified by external standard method.Spirodiclofen,trifloxystrobin,pyraclostrobin,2,4-butyl ester and tefluthrin had good linear relationships in the range of 0.01-2.0μg/mL,with correlation coefficients(r2)were all above 0.995.Their detection limits were as follows:spirodiclofen:4.23μg/L,trifloxystrobin:3.52μg/L,pyraclostrobin:3.69μg/L,2,4-butyl este:2.26μg/L and tefluthrin:1.25μg/mL.Recoveries of this method in 3 concentration levels were ranged from 90.9%to 101.3%.The results of RSD of precision were 1.68%-4.03%(n=6).The method has good purification effect,accurate qualitative and quantitative results,and is suitable for the monitoring of pesticide residues in water samples.