分散液相微萃取测定苹果中灭线磷马拉硫磷和毒死蜱残留

Dispersed Liquid Phase Microextraction Determination of Phosphorus,Sulfur Destroyed Line Malachy Phosphorus and Chlorpyrifos Residue

采用液液分散微萃取与气相色谱-火焰光度检测器联用技术,提出了可用于苹果中有机磷农药残留检测的一种快速、灵敏的新方法,并通过试验对提取条件进行了优化。结果表明,该方法成功地应用到苹果样本的检测。在优化的条件下最低检出限从1.32-3.58μg.mL^-1,相对标准偏差为11.06%-15.39%,分析标准曲线采用五点法（浓度从0.5-20μg.mL^-1）来绘制,线性的变化从0.977 3-0.997 6。为了评价样本的基质效应,用有机磷农药从3个不同浓度水平对样本进行添加,回收率从64.0%-89.0%,并且没有发现基质效应。液液分散微萃取不仅操作简便而且有机溶剂使用量极少,是一种顺应时代要求的环境友好型萃取方法。

A rapid and sensitive method based on dispersive liquid-liquid microextraction（DLLME）and gas chromatography-flame photo-metric detection（GC-FPD）has been successfully applied to the determination of organphosphorus pesticides residues（OPPs）in apples.The factors that influenced the extraction were optimized in the experiment.The optimum conditions：5.0 mL apple sample was placed in 10.0 mL centrifuge tube,then the mixture of 1.5 mL acetone（disperser）and 30 μL 1,2-dichlorobenzene（extracter）was injected into the sample solu-tion rapidly.Vibrate for 1 minute then centrifuge at the rate of 3 500 r.min-1 for 5 minutes,the extract phase was sedimented at the bottom of the centrifuge tube,transfer 1 μL to GC system for analysis.Under the optimum condition,based on signal-to-noise ratio（S/N）of 3,limits of detection ranged form 1.32 to 3.58 μg.mL-1.The relative standard deviations（RSD,n=3）were between 11.06% and 15.39%.Correlation co-efficients varied from 0.977 3 to 0.997 6.The developed method was successfully applied in the analysis of apple samples.In order to evalu-ate the matrix effects of the samples,organophosphorus pesticide was added to the apples by using three different concentrations.The recov-eries were ranged from 64.0% to 89.0%,and no matrix effect was observed.The results showed that the method was comparatively simple,fast and effective.