粮谷中11种二硝基苯胺类除草剂残留量的气相色谱-串联质谱法测定

Determination of 11 Dinitroaniline Herbicide Residues in Grains by Gas Chromatography-Tandem Mass Spectrometry

建立了粮谷中11种二硝基苯胺类除草剂残留量的气相色谱-串联质谱(GC-MS/MS)测定方法,样品经乙腈提取、QuEChERS法净化,采用GC-MS/MS在多反应监测模式下进行快速分析,外标法定量。在优化实验条件下,11种二硝基苯胺类除草剂的线性范围均为1.0～20.0μg/L,相关系数大于0.996,方法定量下限为5μg/kg;在加标水平为5、10、20μg/kg时,大米、大豆、小麦样品中11种二硝基苯胺类除草剂的平均加标回收率为65%～110%,相对标准偏差(n=7)为2.6%～10.2%。

A gas chromatography-tandem mass spectrometric（GC-MS/MS） method was established for the determination of 11 dinitroaniline herbicide in grains products.The samples were extracted with acetonitrile,and cleaned up by the QuEChERS method.A rapid analysis was carried out by GC-MS/MS under multiple reaction monitoring（MRM） mode.The external standard was used for quantitative analysis.Under the optimal conditions,the calibration curves for the 11 dinitroaniline herbicides were linear in the range of 1.0-20.0 μg/L with correlation coefficients more than 0.996.The quantitation limit of the method was 5 μg/kg.The mean recoveries for rice,soybean and wheat samples at three spiked concentrations levels of 5,10,20 μg/kg were in the range of 65%-110% with relative standard deviations（RSDs,n=7） of 2.6%-10.2%.