脉冲式火焰光度检测器(PFPD)分析蔬菜中有机磷农药残留

Analysis of Organophosphorous Pesticide in Vegetables with Pulsed-flame Photometer Detector (PFPD)

分别采用乙腈-氯化钠法、三氯甲烷法和丙酮-二氯甲烷法提取蔬菜样品中残留的有机磷农药,使用带脉冲式火焰光度检测器(PFPD)的气相色谱法比较了三种提取方法有机磷农药的提取效率,使用带火焰离子检测器(FID)的气相色谱法分析了三种提取方法杂质溶出量。综合两种检测器的分析结果优化了蔬菜中有机磷农药的提取分析方法:采用乙腈-氯化钠法提取蔬菜样品中的有机磷农药残留,GC-PFPD法分析农药残留。该方法对所测四种农药(敌敌畏、乙酰甲胺磷、甲拌磷、乐果)的最低检出限LOD分别为2.2、43.0、5.0、2.3ng/ml(进样量1μl),回收率在95%～120%之间,日内精密度和日间精密度RSD值都小于9.5%。该方法操作简单,灵敏度高,适用于蔬菜类样品的检测。

Acetonitrile-sodinm chloride, trichlommethane and acetone-dichloromethane were used to extract organophosphorous pesticides respectively. Pulsed-flame photometer detector （PFPD） was used to analyze the extraction rate of these three solvents. Flame ionization detector （FID） was used to analyze the content of impurity in the samples extracted by those three solvents. An optional extraction and analysis method has been identified according to the analysis results with FID and PFPD. The organophosphorous pesticides in vegetables were extracted by acetonitrile-sodium chloride analyzed with PFPD. The limit of detectionCLOD） of the four pesticides （dichlorvos, acephate, phorate and dimethoate） in this method was respectively 2.2, 43.0, 5.0, 2.3 ng/ml, the rate of recoveries were all between 95%- 120%, and the intra-day RSD and inter-day RSD were all below 9. 5%. This method is easy to perform and has a high sensitivity.