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目的建立茶叶中3种有机氯和16种拟除虫菊酯农药残留的毛细管气相色谱测定方法。方法茶叶经过研磨后准确称取2.0 g,样品加入20 ml乙腈超声、震荡提取,离心后取10 ml上层乙腈溶液,溶液经过旋蒸蒸干后通过Cleanert PC/NH2柱和硅镁柱净化2次,最后使用正己烷定容至1 ml,DM-17石英毛细管色谱柱分离,电子俘获检测器(ECD)测定,外标法定量,一次性分析茶叶中19种有机氯类和拟除虫菊酯类农药的残留量。结果 19种农药的分离效果好,线性关系良好,平均回收率在65%~123%之间,RSD在2.5%~7.3%之间,本实验具有较好的回收率和精密度,可以满足实际检测需求。结论该方法快速、简便,准确度和精密度良好,可用于茶叶中多种有机氯和拟除虫菊酯农药残留的测定。
Objective To establish a method for the determination of three organochlorines and sixteen pyrethroid pesticide residues in tea by capillary gas chromatography. Methods After grinding, the tea weighed 2.0 g accurately. The samples were extracted with 20 ml acetonitrile and extracted by shaking. After centrifugation, 10 ml of the upper acetonitrile solution was obtained. The solution was evaporated to dryness and cleaned twice with Cleanert PC / NH2 column and silica gel column , And finally with n-hexane to 1 ml, DM-17 quartz capillary column separation, electron capture detector (ECD) determination, external standard quantitative, one-time analysis of 19 kinds of organic chlorine and pyrethroid pesticides in tea The amount of residue. Results 19 kinds of pesticides had good separation effect and good linearity. The average recoveries ranged from 65% to 123% with RSDs ranging from 2.5% to 7.3%. The experimental results showed good recovery and precision, Testing needs. Conclusion The method is rapid, simple, accurate and accurate. It can be used for the determination of various organochlorine and pyrethroid pesticide residues in tea.