加速溶剂萃取法测定大枣中有机氯及拟除虫菊酯类农药残留量

目的建立快速同时测定大枣中50种有机氯及拟除虫菊酯农药残留的气相色谱测定方法。方法样品用加速溶剂萃取法(ASE)萃取,以乙腈(1%乙酸)为提取溶剂,温度100℃,静态萃取5 min,循环3次,提取液用Florisil硅土柱净化,乙酸乙酯-正己烷(15∶85,V/V)洗脱,采用HP-5与DB1701毛细管色谱柱双柱定性,以HP-5毛细管柱定量,GC-ECD检测器进行检测。结果样品3水平添加时的50种有机氯及拟除虫菊酯农药平均回收率为71.4%~110.9%,RSD为1.2%~14.1%,符合农药残留分析的要求。结论本方法仪器简单,使用范围广,重复性及净化效果好,可用于大枣中50种有机氯及拟除虫菊酯类农药残留量检测。

Determination of Organochlorine and Pyrethroid Pesticides Residues in Zigyphussp by Accelerated Solvent Extraction

Objective To establish a gas chromatography method for the determination of 50 organochlorine and pyrethroid pesticides residues in Zigyphussp. Methods The organochlorine and pyrethroid pesticides were extracted from Zigyphussp with solvents of acetonitrile （1%acetic acid） by accelerated solvent extraction （ASE） for 5 min at 100℃. Then the extracts were cleaned up by alumina neutral-florisil column and eluted by mixed solvents of ethyl acetate and hexane （15∶85, V/V）. The extract was separated by HP-5 and DB1701 capillary dual-column and detected by electron-capture detector. Results The average recoveries and RSD ranged from 71.4% to 110.9%and 1.2% to 14.1% respectively, at three spiked mixed organochlorine and pyrethroid levels. Conclusion The method has good separation and repeatability, and can be used in determination of organochlorine and pyrethroid pesticide residues in Zigyphussp.