气相色谱法测定茶叶中有机氯和拟除虫菊酯农药残留的研究

Study on Multiresidue Determination of Organochlorine and Pyrethroid Pesticides in Tea by Gas Chromatography

[目的]研究茶叶中农药残留的检测分析方法。[方法]茶叶样品用乙腈超声波提取，浓缩后经Florisil固相萃取柱净化，采用丙酮-正己烷（V：V=1：9）溶液淋洗，利用毛细管气相色谱法检测茶叶中的农药残留。[结果]结果表明，该方法的线性范围为0．01～0．50mg／L，茶叶样品加标浓度为0．01～0．50mg／kg时，回收率为85．0％～101．1％，相对标准偏差为1．5％～7．8％。[结论]该方法满足茶叶中有机氯和拟除虫菊酯农药残留分析的要求。

[ Objective] The purpose aimed to study the method of determining and analyzing organochlorine and pyrethroid pesticides in tea. [ Method ] An analytical multi-residue method for simultaneous determination of 11 pesticides （8 organochlorines and 3 pyrethroids） in tea was developed. Pesticides were extracted from tea with aeetonitrile in an ultrasonic bath and cleaned up on a Florisil＇ s SPE column by acetone and n-hexane, then were determined by gas chromatography with μ-ECD detection. [ Result] The results indicated that the average recoveries for the pesticides ranged from 85.0% to 101.1%, with the relative standard deviation （RSD）between 1.5% and 7.8% for all compounds. [ Conclusion] The method is satisfied with the determination demands of organoehlorine and pyrethroid pesticide multi-residues for tea samples.