目的:基于多壁碳纳米管(Multi Walled Carbon Nanotubes,MWCNTs)改良QuEChERS结合气相色谱法(Gas Chromatography,GC),建立同时测定茶叶中 17 种有机磷类农药残留的分析方法.方法:比较了 4 种不同方法的农药残留回收率和提取净化效果,采用丙酮提取样品,经MWCNTs改良QuEChERS方法净化,通过GC进行分析,基质匹配外标法进行定量.结果:17 种目标农药在 0.005~1.000 μg·mL-1线性关系良好(r≥0.998 1),检出限为 0.010~0.015 mg·kg-1,定量限为 0.03~0.05 mg·kg-1,在0.05 mg·kg-1、0.50 mg·kg-1、2.00 mg·kg-1 3个添加水平下,平均回收率为82.5%~111.4%,相对标准偏差(n=6)为 1.2%~8.1%.结论:该方法节省试剂、操作便捷、准确高效,可以满足基层检验机构同时检测茶叶中17 种有机磷类农药残留的要求.
Objective:To establish an analytical method for simultaneous determination of 17 organophosphorus pesticide residues in tea using modified QuEChERS method based on multi walled carbon nanotubes(MWCNTs)coupled with gas chromatography(GC).Method:The recoveries of pesticide residues and purification effects of four different method were compared,the samples were extracted with acetone,purified using modified QuEChERS based on MWCNTs,then analyzed by GC and quantified by matrix matched external standard method.Result:The reliable linear relationship in the range of 0.005~1.000 μg·mL-1 were observed for 17 pesticides(r≥0.998 1),the limit of detection were 0.010~0.015 mg·kg-1,and the limit of quantification were 0.03~0.05 mg·kg-1.The average recoveries of three spiked levels(0.05 mg·kg-1,0.50 mg·kg-1 and 2.00 mg·kg-1)were 82.5%~111.4%,the relative standard deviation(n=6)were 1.2%~8.1%.Conclusion:This method is solvent saving,easy to operate,accurate and efficient,and can meet the requirements of grassroots inspection institutions for the simultaneous determination of 17 organophosphorus pesticide residues in tea.