GC-ECD检测茶叶中4种拟除虫菊酯类农药残留研究

GC-ECD Detection on 4 Kinds of Pyrethroid Pesticides Residue in Tea

本文采用固相萃取法结合旋转蒸发技术进行样品的前处理，经气相色谱-电子捕获检测（GC—ECD）进行溴氰菊酯、氰戊菊酯、联苯菊酯、氯氰菊酯四种菊酯类农药残留的检测分析。茶叶样品过40目网筛，60℃震荡提取30min，固相萃取法进行前处理，经GC—ECD检测，基质外标法定量。结果表明：茶叶基质中，4种菊酯类农药峰面积响应值与其质量浓度在10～200μg／L范围内呈良好线性关系（R2〉0．897）。在80、160μg／L二个添加水平下，4种拟除虫菊酯类农药的回收率在78．77％～125．78％，相对标准偏差为2．58％～5．78％。该方法简便快速、准确灵敏，适合茶叶中菊酯类农药残留的检测和安全监控。

GC -ECD with dispersive solid phase extraction combined with rotary evaporator was applied to the determination of dehamethrin, feuvalerate, bifenthrin, eypermethrin four pyrethroid pesticides in tea. The samples were purified by a QuEChERS method after over 40 mesh sieve,60℃ shock extraction 30min ,followed by analysis by GC -ETD and quantified by the matrix matched external standard method. The calibrationcurves showed good linearity with correlation coefficient（ R2 ）larger than 0. 897 in tea, the linear range of the above 4 kinds of pyrethroid pesticides were 10 - 200μg/L. The method validation was carried out at 80,160μg/L,the recoveries were from78.77% to 125.78%, and the RSDs were from 2.58% to 5.78% This method was simple,quick,accurate, sensitive and it was suitable for the detection and security monitoring of pyrethroid pesticides residue in tea.