固相萃取-高效液相色谱法测定桔梗中拟除虫菊酯的农药残留

目的: 建立桔梗中甲氰菊酯、高效氯氟氰菊酯、溴氰菊酯、氰戊菊酯、氯菊酯、联苯菊酯共6个拟除虫菊酯类农药残留的提取、净化及其残留量测定的方法。 方法: 样品运用石油醚提取,商品CARB/NH₂小柱净化,乙腈-二氯甲烷(5∶ 95)洗脱,HPLC-DAD检测。色谱条件: 采用Hypersil BDS C₁₈(250 mm×4.6 mm,5 μm)色谱柱,流动相为乙腈-水(70∶ 30),流速1 mL·min^-1,检测波长230 nm。 结果: 样品4水平添加时的6个拟除虫菊酯类化合物回收率在75.63%~107.5%范围内,RSD在2.3%~9.9%范围内,可以满足农药残留分析的要求。 结论: 该方法灵敏度高,选择性强,操作简单、快速,净化效果好。可应用于桔梗药材中痕量农药残留的检测。

Objective: To develop a method for the extraction,clean-up and determination of fenpropathrin,lambda-cyhalothrin,deltamethrin,fenvalerate,permethrin and bifenthrin in Platycodon grandiflorum. Methods: Pesticide residues were extracted from samples with ligarine;Extracts were cleaned-up by CARB/NH₂ column,eluted with acetonitrile-chloromethane(5∶ 95).Analytical screening was determined by HPLC with a diode array detector.HPLC condition:Hypersil BDS C₁₈(250mm×4.6 mm,5 μm)column was adopted,the mobile phase consisted of acetonitrile-water(70∶ 30)at a flow rate of 1 mL·min^-1,and the detection wavelength was 230 nm. Results: The average recoveries were in the range of 75.63%-107.6% with RSD of 2.3%-9.9%.The method met the requirement of pesticide residue analysis. Conclusion: The proposed method has high sensitivity,repeatability and selectivity,it is simple and fast,which can be used for the analysis of 6 pyrethroid pesticides.