Determination of Several Pesticide Residuesin in Tea Samples by Gas Chromatography

采用氟罗里硅土 /活性炭混合柱柱层析净化方法 ,以HP 5毛细管柱、电子捕获检测器 (ECD)的气相色谱(GC)方法测定了茶叶中六六六、三氯杀螨醇、滴滴涕、联苯菊酯、甲氰菊酯、氯氰菊酯和氰戊菊酯等多种农药残留 .所建立方法的分析结果与外检结果基本一致 .方法具有溶剂使用量少、净化效果好、操作简便、快速等特点 ,可满足茶叶中多种农药残留检测的需要 .A method for determination of several pesticide residues in tea sample has been developed with electron capture detector gas chromatography (ECD GC) with HP 5 capillary column. Residues of α BHC, β BHC, γ BHC, δ BHC, Dicofol, p, p′ DDE, p, p′ DDD, o, p′ DDT, p, p′ DDT, bifenthrin, fenpropathin, cypermethrin and fenvalerate in real world tea samples were first extracted at 40 ℃ by mixture of hexane and acetone (97.5∶2.5, V/V ). And then, the analytes were purified by column (70 mm×5 mm) packed with 300mg Florisil and top packed with 15 mg active carbon. Petroleum ether mixed with acetic ether (9∶1, V/V ) was selected to elute the residues from purified column. Good results for standard recovery have been obtained in the range of 0～100 ng in 1.0 mL sample solution. Relative standard deviations were less than 13.7% ( n =5, with standard spiked sample). The analytical results with this method and an external compared method are in good agreement