QuEChERS-气相色谱-三重四极杆串联质谱法测定茶叶中20种农药残留

Determination of 20 Pesticide Residues in Tea by QuEChERS-Gas Chromatography-Triple Quadrupole Mass Spectrometry

建立一种改良QuEChERS技术结合气相色谱-三重四极杆串联质谱(GC-MS/MS)测定茶叶中20种农药残留的分析方法。茶叶样品采用乙腈-乙酸乙酯(1∶1,V/V)提取后经净化管Ⅲ(400 mg PSA,400 mg C_(18),200 mg GCB,1200 mg MgSO_4)净化处理,用GC-MS/MS在多反应监测(MRM)模式下进行分析检测,阴性基质提取液配制系列标准工作溶液,外标法定量。结果表明,20种农药在质量浓度为0.01~10μg/mL范围内线性关系良好,相关系数均大于0.99666,方法的检出限为0.0112~0.3154μg/kg,定量限为0.0373~1.0513μg/kg;向阴性空白样品中添加0.01、0.50、10.00 mg/kg 3水平加标浓度,其20种农药的加标回收率为73.65%~99.25%,精密度为0.078%~11.210%。该方法具有操作简单、高效准确、成本较低等优势,适用于茶叶中农药残留的快速检测。

In the present study,an improved QuEChERS method combined with gas chromatography-triple quadrupole tandem mass spectrometry(GC-MS/MS)was established for the determination of 20 pesticide residues in tea.The tea samples were extracted by acetonitrile-ethyl acetate(1∶1,V/V),purified by purification tube Ⅲ(400 mg PSA,400 mg C18,200 mg GCB,1200 mg MgSO_(4)),and analyzed by GC-MS/MS in multiple reaction monitoring(MRM)mode.A series of standard working solutions were prepared and quantified by external standard method.The results showed that the linear relationships of 20 pesticides were good in the mass concentration ranges of 0.01~10μg/mL,and the correlation coefficients were all greater than 0.99666.The detection limits were 0.0112~0.3154μg/kg,and the quantification limits were 0.0373~1.0513μg/kg.The recovery rates of 20 pesticides in blank samples spiked with 0.01,0.50,and 10.00 mg/kg at three levels were 73.65%~99.25%,with relative standard deviations of 0.078%~11.210%.The method has the advantages of simple operation,high efficiency and accuracy,low cost,and is suitable for the rapid detection of pesticide residues in tea.