固相萃取-气相色谱/质谱联用法检测茶叶中15种农药残留

Determination of 15 pesticides Residues in Tea by Solid Phase Extraction-Gas Chromatography/Mass Spectrometry

目的:建立同时测定茶叶中15种农药残留的气相色谱-质谱联用法。方法:准确称取样品,经均匀粉碎、加水浸泡后,乙腈萃取,氮气吹至近干,采用丙酮、二氯甲烷复溶,PC/NH_(2)-SPE固相萃取柱净化,上机测定,外标法定量。结果:同时测定15种农药分离效果好,标准曲线相关系数均大于0.996,检出限为0.024~0.840μg·kg^(-1),平均加标回收率为85.3%~92.8%,RSD为3.8%~8.6%。结论:所建立的方法回收效果好,操作简便快速,准确度与精密度均较高,适用于茶叶中多种农药残留的测定。

Objective:To establish a method for detecting 15 pesticides residues in tea by gas chromatography/mass spectrometry.Method:Crushed the sample and soak it in water,then extracted by acetonitrile,and blow the organic nitrogen to dry.Redissolved by acetone and dichloromethane the sample and purified through PC/NH_(2)-SPE column.Detected the homogenized samples by gas chromatography/mass spectrometry and analysed by external standard method.Result:Simultaneous determination of 15 pesticides has good separation effect.The correlation coefficients of the standard curve are all more than 0.996.The minimum detection concentration were 0.024~0.860 mg·kg^(-1),the average recovery rates were 85.3%~92.8%and the RSD were 3.8%~8.6%.Conclusion:The established method has good recovery effect,simple and convenient operation,high accuracy and precision,and is suitable for the determination of various pesticides residues in tea.