苹果中三氟氯氰菊酯残留GC-ECD测定

对苹果中三氟氯氰菊酯残留量进行了GC-ECD测定。苹果样品中农药残留采用乙腈代替传统的丙酮-石油醚作为提取剂,提取溶液比较干净,通过弗罗里硅土层析柱净化,GC-ECD测定,既节省了溶剂用量、节省了时间又简化了预处理步骤。隔垫吹扫和玻璃衬管内填充玻璃棉消除了因样品蒸发的反扩散、吸附和垫片流失所造成的色谱峰拖尾和鬼峰的干扰。本研究得到的苹果全果、果皮和果肉中三氟氯氰菊酯添加回收率分别达到92.54%±2.3%~103.32%±4.4%、96.00%±2.8%~101.23%±2.9%和92.50%±3.6%~104.02%±2.9%;三氟氯氰菊酯的最小检出限为5.70×10-11g,方法简单、快速,且回收率和灵敏度高,变异系数小。

Determination of Cyhalothrin Pesticide Residue in Apple by GC-ECD

The study on the determination of cyhalothrin pesticide residues by GC-ECD in apple was established.The residues were extracted from apple with acetonitrile which substitute the mixture of acetone and petroleum ether,and the extraction solution has little impurity and comparatively cleaning,decontaminate with Florisil,and determined by GC with electron capture detector,the step of preparation was simplified,and the method reduced solvent consumption,saving time,as well.The method of infilling glass cotton in glass inner tube avoided the disturbance of chromatography peak and impurity peak which because reverse pervasion and adsorption of sample vaporing and septum lose.The recoveries of the three spiked levels of cyhalothrin were from 92.54%±2.3% to 103.32%±4.4% in whole apple,from 96.00%±2.8% to 101.23%±2.9% in apple peel and from 92.50%±3.6% to 104.02%±2.9% in apple pulp.The minimum detection limits of cyhalothrin were 5.70×10^-11g.It was a sensitive,simple and reliable method to determinethe residues of cyhalothrin in apple,the result of recovery rate and coefficient of variation and minimum detection limits were famous.