UPLC-MS/MS检测甘蓝中甲氨基阿维菌素苯甲酸盐和除虫脲残留和消解

Determination of Emamectin Benzoate and Diflubenzuron Residue and Dissipation Dynamics in Cabbage Using UPLC-MS/MS

为明确甲氨基阿维菌素苯甲酸盐(甲维盐)和除虫脲在甘蓝上的残留行为和消解动态,进行了田间试验,并建立了超高效液相色谱-串联三重四极杆质谱(UPLC-MS/MS)检测方法。结果表明,在添加水平0.001~1.00 mg/kg范围内,甲维盐在甘蓝中的平均回收率为99.1%~104%,相对标准偏差(RSD)值为3.02%~8.70%;在添加水平0.002~2.00 mg/kg范围内,除虫脲的平均回收率为97.2%~101%,RSD值为4.03%~6.96%。定量限(LOQ)值分别为0.001、0.002 mg/kg。甲维盐在甘蓝中的平均原始沉积量不大于7.06×10-3 mg/kg,不符合一级动力学方程,无法拟合降解曲线。除虫脲在甘蓝中的消解动态符合一级动力学方程,其降解半衰期为2.31~6.08 d,说明该药剂属于易消解农药。

In order to find out the residual behavior and degradation dynamics of emamectin benzoate and diflubenzuron in cabbage,field experiments were carried out,and the detection method of emamectin benzoate and diflubenzuron in cabbage by ultra high performance liquid chromatography tandem triple quadrupole mass spectrometry(UPLC-MS/MS)was established.The results showed that the average recovery of emamectin benzoate in cabbage was 99.1%-104%and RSD was 3.02%-8.70%in the range of 0.001-1.00 mg/kg.In the range of 0.002-2.00 mg/kg,the average recovery of diflubenzuron was 97.2%-101%,RSD was 4.03%-6.96%.LOQ was 0.001 and 0.002 mg/kg,respectively.The average original deposition of emamectin benzoate in cabbage was less than 7.06×10-3 mg/kg,which was not in accordance with the first-order kinetic equation and could not fit the degradation curve.The degradation kinetics of diflubenzuron in cabbage were accorded with the first-order kinetic equation,and its half-life was 2.31-6.08 d,which showed that diflubenzuron was easy to digest.