分散液相微萃取-气相色谱-串联质谱法快速测定蔬菜中8种亲脂类农药残留

建立了分散液相微萃取-气相色谱-串联质谱(GC-MS/MS)联用方法用于快速分析蔬菜中8种亲脂类农药残留。样品用水-丙酮(5:1, v/v)混合溶液提取,经布氏漏斗减压抽滤。滤液经N-丙基乙二胺(PSA)吸附剂、C18吸附剂、石墨炭黑粉净化后,用氯苯萃取,GC-MS/MS测定。对影响萃取和富集效率的因素进行了优化。在优化的实验条件下,农药的富集倍数达526～878,检出限为0.001～0.02 mg/kg,线性范围为0.005～10 mg/kg,线性相关系数为0.9921～0.9989,平均加标回收率为60.1%～82.5%,相对标准偏差为1.2%～9.6%。该方法已成功应用于蔬菜中8种亲脂类农药残留的测定。

Rapid analysis of eight lipophilic pesticide residues in vegetables by dispersive liquid-liquid microextraction coupled with gas chromatographytandem mass spectrometry

A novel method for rapid determination of eight lipophilic pesticides in vegetables was developed using dispersive liquid-liquid micro-extraction(DLLME) coupled with gas chromatography-tandem mass spectrometry(GC-MS/MS).The analyte in the vegetable was extracted with water-acetone(5∶1,v/v) solution.Then,the extract was transferred into a centrifugal tube with 25 mg primary secondary amine(PSA),50 mg C18 and 25 mg graphitized carbon black powder.The important parameters that affected the extraction efficiency were studied,such as the extraction and dispersed solvents,and the extraction time.The results showed that a good extraction efficiency was obtained,with acetone used as the dispersed solvent and 50.0 μL chlorobenzene used as the extraction solvent.Under the optimum conditions,the enrichment factors ranged from 526 to 878.The linearity ranges of the eight targeted compounds were 0.005-10 mg/kg,and the limits of detection(signal/noise=3) were 0.001-0.02 mg/kg,with the correlation coefficients varying from 0.9921 to 0.9989.The recoveries of the pesticides ranged from 60.1% to 82.5% with the relative standard deviations between 1.2% and 9.6%.The method has been used to analyze the eight lipophilic pesticide residues in vegetable samples with satisfactory results.