茶叶中12种农药残留量的QuEChERS-液相色谱-串联质谱法测定

目的]建立测定茶叶中12种农药残留量的液相色谱-串联质谱(LC-MS/MS)检测方法。方法]茶叶样品经乙腈提取后,采用QuEChERS方法前处理,净化液经液相色谱-串联质谱测定,基质内标法定量。结果]在0.001~0.1 mg/L范围内,12种农药的线性关系良好,相关系数r2大于0.997,方法检出限为0.0003~0.01 mg/kg,定量限为0.001~0.04 mg/kg。阴性茶叶样品在低、中、高3个添加水平下的平均回收率为80.6%~106.6%,相对标准偏差为0.4%~8.2%。结论]与传统的QuEChERS相比,该方法具有操作简单、快速、试剂用量少、回收率高、准确性强等特点,适合于茶叶中12种农药残留量的测定。

Determination of 12 Pesticide Residues in Tea by QuEChERS Coupled to Liquid Chromatography-Tandem Mass Spectrometry

Aims]This study aims to develop a method for the determination of 12 pesticide residues in tea by Liquid Chromatography-Tandem Mass Spectrometry(LC-MS/MS).Methods]The target pesticides in tea were extracted by a modified QuEChERS method with acetonitrile as the solvent.The quantification was performed by the matrix internal standardmethod.Results]Good linearitywas observed for all calibration curveswith correlation coefficients(r2)>0.997 in the range of 0.001-0.1mg/L.The limits of detections(LODs)were 0.0003-0.01mg/kg,and the limits of quantitation(LOQs)were 0.001-0.04 mg/kg.The recoveries at three spiked levels varied from 80.6 to 106.6%,with relative standard deviations(RSDs)of 0.4-8.2%.Conclusions]Comparedwith the traditionalQuEChERSmethod,thismethod is easy,fast and solvent savingwith good recoveryand accuracy.Thus,it is suitable for the determination of12 pesticide residues in tea.