分散固相萃取-分散液液微萃取/气相色谱-串联质谱法测定蔬菜中19种有机磷农药残留

采用分散固相萃取和分散液液微萃取联用方法,建立了气相色谱-串联质谱法(GC-MS/MS)同时测定蔬菜中19种有机磷农药残留量的分析方法。分散固相萃取方法以乙腈为萃取液,以N-丙基-乙二胺(PSA)和C18为吸附剂。对影响分散液液微萃取效率的因素(萃取溶剂种类及体积、分散剂体积等)进行优化,同时分析了实验过程中添加掩蔽试剂L-古洛糖酸γ-内酯(AP)对基质效应补偿作用的影响。在最佳实验条件下,19种有机磷在辣椒和大葱中3个添加水平(0.05,0.1,0.5 mg/kg)的回收率为76.9%~126.8%,相对标准偏差为0.6%~7.3%,检出限(S/N=3)为0.10~0.50μg/kg。该方法简单、高效、重现性好、富集倍数高,可用于蔬菜中有机磷农药的快速检测。

Determination of Nineteen Organophosphorus Pesticides in Vegetables by Gas Chromatography-Tandem Mass Spectrometry Combined with Dispersive Solid-phase Extraction and Dispersive Liquid-Liquid Micro-extraction

A gas chromatograpy-tandem mass spectrometric (GC-MS/MS) method for the determination of nineteen organophosphorus pesticides in vegetables was developed using dispersive solidphase extraction(DSPE) and dispersive liquid-liquid micro-extraction (DLLME) as sample preparation methods.With dispersive solid-phase extraction,PSA and C18 were used as the sorbents,and acetonitrile as the eluted solvent.Some experimental parameters influencing the extraction efficiency,such as the types and volume of the dispersive solvents and extraction solvents were examined and optimized.Gamma-L-gulonic acid lactone(AP) used as a masking regent for compensation effect of matrix was evaluated.Under the optimum conditions,the recoveries of nineteen organophosphorus pesticides in pepper chili and shallot samples at fortified levels of 0.05,0.1,0.5 mg/kg ranged from 76.9％ to 126.8％ with relative standard deviations of 0.6％-7.3％.The limits of detection(S/N =3) were in the range of 0.10-0.50 μg/kg.With the advantages of quickness,low toxicity and high enrichment factors,the proposed method is applicable for the analysis of organophosphorus pesticides in vegetables.