气相色谱–电子捕获检测法测定食品中有机氯类和拟除虫菊酯类农药残留量

Determination of organochlorine and pyrethroid pesticides in food samples by gas chromatography-electron capture detection

目的 建立不同食品基质中有机氯类和拟除虫菊酯类农药的通用前处理技术,结合气相色谱–电子捕获检测器(gas chromatography–electron capture detector,GC-ECD),实现有机氯类和拟除虫菊酯类农药的快速定量分析.方法 本研究选择15种有机氯类和拟除虫菊酯类农药作为对象,采用乙腈提取,无水硫酸钠干燥,Forisil固相萃取、结合浓硫酸磺化净化技术,通过GC-ECD检测,完成样品中有机氯类和拟除虫菊酯类药物的同时快速测定.结果 此方法最低检出限和定量限分别达0.25μg/kg和0.50μg/kg,同时选用3个不同浓度的加标实验,回收率在70.0%~100%之间,相对标准偏差皆小于10%.结论 本方法操作简便、高效、灵敏度高,易于普及,适用于不同食品基质中有机氯类和菊酯类药物的同时检测.

Objective To establish general pretreatment techniques for the organochlorine and pyrethroid pesticides in different food matrices, and achieve rapid quantitative analysis of organochlorine and pyrethroid pesticides combined with gas chromatography-electron capture detectors(GC-ECD). Methods Fifteen kinds of organochlorine and pyrethroid pesticides were selected for target analytes. The pretreatment method was applied consisting of acetonitrile extraction, dring by anhydrous sodium sulfate, cleaning by solid-phase extraction with Forisil column, followed by concentrated sulfuric acid sulfonation. Then the analysis method was developed combined with GC-ECD. Results The minimum detection limit and the quantitation limit of this method were 0.25 μg/kg and 0.50 μg/kg, respectively. The recoveries for fifteen kinds of pesticides were between 70.0%-100% at three spiking levels in blank sample matrix. The relative standard deviations(RSD) were all less than 10%. Conclusion This method is simple, efficient, sensitive and easy to popularize, which is suitable for simultaneous detection of organochlorine and pyrethroids in different food substrates.