脉冲火焰光度-气相色谱法测定果蔬中27种有机磷农药残留研究

Determination of 27 Organophosphorus Pesticides Residue in Fruits and Vegetables by Gas Chromatography With PFPD

目的建立水果蔬菜中27种有机磷农药残留的脉冲火焰光度检测器-气相色谱分析方法,用于测定市售果蔬有机磷农药残留。方法果蔬样品经含有1%乙酸的乙腈超声提取,提取效率通过加入乙酸-乙酸钠缓冲体系和无水硫酸镁得到改善,60℃水浴浓缩至近干,丙酮溶解定容后直接用脉冲火焰光度检测器测定。结果27种有机磷农药在0.1～1.0μg/ml浓度范围内成线性,方法检出限均小于0.01mg/kg,样品平均加标回收率为67.5%～119.8%,相对标准偏差为1.3%～18.3%。结论该法灵敏、准确、快速、操作简便,适合于新鲜果蔬有机磷农药残留的市场调查研究。

Objective To develop a method for determination of 27 organophosphorus pesticides in fruits and vegetables by gas chromatography with PFPD. Method Pesticide samples were extracted with acetonitrile containing 1% acetic acid by ultrasonic wave. Extraction efficiency can be improved by adding sodium acetate-acetic acid buffer system and anhydrous magnesium sulfate. After evaporation the extract on water-bath at 60℃ to nearly dryness, the residue was dissolved in acetone and analyzed directly by GC coupled with PFPD. Results The calibration curves of 27 organophosphorus pesticides were linear within 0. 1 - 1.0 μg/ml. The detection limits were all below 0. 01mg/kg, Average recoveries for all the pesticides studied were in the range 67.5% - 119. 8% and relative standard deviations were 1.3% - 18. 3%. Conclusion The method is sensitive, accurate, rapid and simple and is suitable for market investigation on organophosphorus residue in fruits and vegetables.