茶叶中34种有机磷和氨基甲酸酯农药多残留的测定

Determination of 34 Organophosphorus and Carbamate Pesticide Multi-Residues in Teas

目的 建立一种快速测定茶叶中有机磷和氨基甲酸酯农药多残留的气相色谱法.方法 样本中农药残留在超声波振荡条件下用乙腈提取,其提取液经氮气流浓缩和凝胶渗透色谱净化,用气相色谱一氮磷检测器测定,色谱柱为HP-5,30 m×0.32 mm×0.25 mm.分析茶叶中26种有机磷类、8种氨基甲酸酯类农药的残留量.结果 农药的添加水平在0.208～0.792 mg/kg范围时,在绿茶中的平均添加回收率为81.2%～114.0%,RSD 为3.45%～13.50%;在花茶中的平均添加回收率为81.3%～110.0%,RSD为3.68%～14.50%;检测限范围为0.02～0.08 mg/kg.结论 本方法的优点是快速、灵敏、准确、成本低,能满足农药多残留快速扫描的分析要求.

Objective To establish a rapid,simple and sensitive method for the determination of organophosphorus and carbamate pesticide multi-residues in teas.Methods The pesticide residues in tea samples were extracted with acetonitrile under the action of ultrasonic oscillation,the extracts were concentrated with nitrogen and cleaned up by gel permeation chromatography,and then determined by GC-NPD.HP-5 capillary column(30 m×0.32 mm×0.25 mm) was used.26 organophosphorus and 8 carbamate pesticide multi-residues in teas were determined by this method.Results When pesticide residues in green tea were at the 0.208-0.792 mg/kg levels,the average rates of recovery were 81.2% 114.0%,the relative standard deviations were 3.45%-13.50%.Moreover,the average rates of recovery ranged from 81.3% to 110.0% with the relative standard deviations ranging from 3.68% to 14.50% in floscular tea.The detection limits of the method were 0.02-0.08 mg/kg.Conclusion The method is suitable for the rapid analysis of pesticide multi-residues in teas.