浊点萃取-正己烷反萃取气相色谱法测定苹果汁中5种有机磷农药残留

CLOUD POINT EXTRACTION COUPLED WITH N-HEXANE BACK-EXTRACTION FOR DETERMINATION OF 5 KINDS OF ORGANOPHOSPHORUS PESTICIDES IN CIDER BY GAS CHROMATOGRAPHY

建立了浊点萃取-正己烷反萃取气相色谱（FPD）法测定苹果汁中的5种有机磷（二嗪磷、嘧啶磷、对硫磷、异柳磷和三唑硫磷）农药残留的方法。采用聚乙二醇4000（PEG 4000）为表面活性剂,所获得的富集相用正己烷进行反萃取,气相色谱FPD检测器检测,外标法定量。结果表明：5种有机磷农药在0.05~2.00 mg/L范围内呈良好的线性关系,线性相关系数在0.9986%~0.9996%之间;添加回收率（浓度为0.0015~0.0300 mg/kg）在72.5%~102.6%之间,RSD为1.97%~7.85%;方法的检出限为0.13~1.50μg/kg。该方法具有操作简单、重现性好、灵敏度高的特点。

A method was developed for the determination of organophosphorus pesticides（diazinon,pyrimithate,thiophos,isofenphos and triazophos） in cider using cloud point extraction（CPE） coupled with n-hexane back-extraction and gas chromatography.Pesticides were extracted with the non-ionic surfactant Polyethylene glycol 4000.The surfactant-rich phase was back extracted by n-hexane.The apparatus was gas chromatography with flame photometric detector（FPD）.The pesticide residues were calculated by external standard method.Good linearrelation was obtained over the range of 0.9986% ~ 0.9996% for these five organophosphorus pesticides in 0.05 ~ 2.00 mg/L.The average recoveries of the five organophosphorus pesticides were 72.5% ~ 102.6% with corresponding RSD of 1.97% ~ 7.85% in the amounts 0.0015 ~ 0.0300 mg/L.The limits of detection（LOD） was 0.13 ~ 1.50 μg/kg in this method.The method was simple,reproducible and of high sensitivity.