QuEChERS结合液相色谱-串联质谱法检测茶叶中34种农药残留

Determination of 34 kinds of pesticide residues in tea by QuEChERS combined with liquid chromatography tandem mass spectrometry

目的建立QuEChERS结合液相色谱-串联质谱法同时测定茶叶中34种农药残留的分析方法。方法样品加入乙腈后使用漩涡混合和超声波提取,应用QuEChERS方法进行净化处理。采用0.05%甲酸水(A)和乙腈(B)作为流动相进行梯度洗脱,质谱(ESI+)采用多反应离子监测模式对34种农药的定量离子和定性离子进行监测。结果本方法在17 min内完成34种目标化合物的分离分析。34种农药在2.5~200μg/L范围内线性关系良好,相关系数(r)均大于0.995,方法的定量限为0.01~5.11μg/kg。34种农药在20、50和100μg/kg添加水平的回收率为70.6%~116.1%,相对标准偏差为1.0%~8.1%(n=6)。结论该方法简单、快速、准确、灵敏高,适合用于茶叶中农药多残留的测定。

Objective To establish a method for the simultaneous determination of 34 pesticide residues in tea by QuEChERS combined with liquid chromatography-tandem mass spectrometry.Methods After adding acetonitrile,the samples were extracted by vortex mixing and ultrasonic wave.The 0.05%formic acid water(A)and acetonitrile(B)were used as mobile phases for gradient elution,and the quantitative and qualitative ions of 34 pesticides were monitored by mass spectrometry(ESI+)in A multi-reactive ion monitoring mode.Results This method completed the separation analysis of 34 target compounds in 17 min.The linear relationship of 34 pesticides was good in the range of 2.5-200μg/L,the correlation coefficients were greater than 0.995,and the limit of quantification were 0.01-5.11μg/kg.The recoveries of 34 pesticides at 20,50 and 100μg/kg levels ranged from 70.6%to 116.1%,and the relative standard deviation was 1.0%-8.1%(n=6).Conclusion This method is simple,fast,accurate and sensitive,which is suitable for detecting 34 pesticide residues in tea.