高效液相色谱-串联质谱法测定土壤中6种白蚁防治农药的残留量

HPLC-MS/MS determination of residual amounts of six termite control pesticides in soil

目的建立土壤中吡虫啉、氯虫苯甲酰胺、氟虫腈及其代谢物等6种白蚁防治农药的高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。方法样品经乙腈高速匀浆提取,甲醇和0.1%甲酸水为流动相进行梯度洗脱,以CAPCELL PAK C18色谱柱(100 mm×2.1 mm,2μm)进行HPLC分离,以电喷雾电离串联质谱正、负离子多反应监测(MRM)模式扫描分析,外标法定量。结果 6种白蚁防治剂在1.00～500μg/L的范围内线性关系良好,相关系数R^2大于0.99,方法定量限范围为0.01～0.05 mg/kg,3个添加水平下的平均回收率范围为86.6%～97.4%,相对标准偏差(RSD)范围为3.62%～11.5%,完全满足日常检测的要求。结论该方法前处理简单、快速、灵敏度高、准确,非常适合于土壤中6种白蚁防治农药残留的快速检测及定量分析。

Objective To establish a high performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS) for the simultaneous determination of lmidacloprid,chlorantraniliprole,fipronil and its metabolites in soil.Methods After the residues of sample were extracted with acetonitrile,they were separated on C18 column with methanol and 0.1% formic acid(V/V) as the mobile phases in gradient program.The analyses were determined by MS/MS under multiple reaction monitoring(MRM) mode, and quantified by matrix matched external standard method.Results The method showed good linearities between the insecticide contents and the peak areas in the range of 1.00 to 500 μg/L,with the correlation coefficients(R^2)higher than 0.99.The limits of quantitation were 0.01-0.05 mg/kg.Theaverage recoveriesofthe six pesticides were in the range of 86.6%-97.4%,with the relative standard deviation of 3.62%-11.5%.Conclusion All the above observations indicate that the established method is easier,faster,more sensitive,and suitable for the qualitative and quantitative confirmation of the six pesticide residues from soil.