茶叶中有机氯和拟除虫菊酯多种农药残留同时分析的样品前处理研究

Study on Pretreatment Method for Determination of Organochlorine and Pyrethroid Pesticides Residues in Teas

建立了茶叶中同时分析12种有机氯和拟除虫菊酯类农药残留的样品提取和固相萃取(SPE)前处理方法.试样在超声条件下用正己烷提取后用自制弗罗里圭(florisil)/石墨化碳复合固相萃取小柱净化,然后采用气相色谱-电子捕获检测器(GC-ECD)测定.研究结果表明,当茶叶中农药加标在4.93～201.00 ng/g范围内时,添加回收率为68.9%～112.2%,相对标准偏差为2.43%～15.8%,方法的检出限范围在2.52～10.59 ng/g.

A rapid and sensitive method has been developed for the preparation and determination of 12 organochlorines and pyrethroid residues in teas at the same time.The tea samples were firstly ultrasonicably extracted with n-hexane,then purified by self-made Florisil/PestiCarb solid phase extraction column,and finally,analysed on a gas chromatograph with an electron capture detector.The recoveries of this method ranged from 68.9%~112.2%while spiked pesticide residues in teas were at 4.93~201.00 ng/g and the relative standard deviations were from 2.43% to 15.8%.The limit of detection of this method ranged from 2.52~10.59 ng/g.