改进的QuEChERS结合高效液相色谱-串联质谱法测定牛奶中麦草畏及代谢物残留量

Determination of Dicamla and Its Metabolite Residues in Milk with Modified QuEChERS-HPLC-MS/MS

目的:建立改进的QuEChERS-高效液相色谱-串联质谱分析牛奶中麦草畏及代谢物残留的检测方法。方法:样品采用乙腈-0.1%乙酸的混合溶液提取,无水硫酸镁和C18净化,高效液相色谱-串联质谱仪的MRM模式进行测定。结果:在2.0~500.0μg·L^(-1),3,6-二氯水杨酸和麦草畏的线性相关系数分别为0.9960和0.9990,回收率分别为76.1%~98.5%和82.1%~103.9%,相对标准偏差分别为5.3%~7.3%和5.4%~8.6%,定量限为10μg·kg-1。结论:该方法操作简便、结果准确,适用于牛奶中麦草畏农药残留的检测。

Objective:To establish an improved QuEChERS high performance liquid chromatography-tandem mass spectrometry method for the determination of dicamla and its metabolites in milk.Method:The samples were extracted with mixed solution of acetonitrile and 0.1%acetic acid,purified by anhydrous magnesium sulfate and C18,and determined by MRM mode of high performance liquid chromatography-tandem mass spectrometer.Result:The linear correlation coefficients of dichlorosalicylic acid and trivaloba in 2.0~500.0μg·L^(-1),3,6-dichlorosalicylic acid and trivaloba were 0.9960 and 0.9990,respectively.The recoveries were 76.1%~98.5%and 82.1%~103.9%,and relative standard deviation were 5.3%~7.3%and 5.4%~8.6%,respectively.The limit of quantification was 10μg·kg-1.Conclusion:The method is simple and accurate,and suitable for the determination of dicamla pesticide residues of dicamba in milk.