分散固相萃取净化茶叶中20种农药残留量的GC-μECD测定  

Determination of 20 pesticide residues in tea by DSPE and GC-μECD

作　　者：叶江雷[1] 金贵娥[2] 庄婉娥[2] 郑文慧 吴云辉[1] 

机构地区：[1]厦门海洋职业技术学院生物系,厦门361102 [2]厦门大学近海海洋环境科学国家重点实验室,厦门361005 [3]厦门茶叶进出口有限公司,厦门361006

出　　处：《分析试验室》2011年第10期115-119,共5页Chinese Journal of Analysis Laboratory

基　　金：厦门市科技计划创新项目(No.3502Z20103045)资助

摘　　要：建立了改进的分散固相萃取(DSPE)提取净化、GC-ECD检测茶叶中六六六、敌敌涕、硫丹、拟除虫菊酯、乙草胺、氟虫腈、溴虫腈等茶叶国际贸易中较为关注的20种农药残留量的方法。前处理过程:(1)以2 mL乙腈提取0.5 g茶叶样品,涡旋振荡2 min,离心5 min(5000 r/min);(2)取1 mL上清液与PSA(25 mg),GCB(7.5 mg),MgSO4(150 mg)吸附净化剂涡旋振荡2 min后,再离心5 min(5000 r/min);(3)整个过程需时约0.5 h;(4)将上清液溶剂置换为正己烷,由GC-μECD检测。提取液净化效果良好,目标农药出峰处没有基质干扰峰;方法的回收率、重现性、检测下限符合欧盟和日本对茶叶中农残检测的要求。实际样品的检测结果与混合溶剂提取、SPE净化检测的结果相似。In this paper,a modified method of DSPE for the determination of 20 pesticide residues in tea was established.These pesticides were BHCs,DDTs,endosulfan,pyrethroid pesticides,acetochlor,fipronil,chlorfenapyr,which were concerned in the tea international trade.The pretreatment procedure was：（1） the target pesticide residues were extracted by 2 mL of pure acetonitrile in 0.5 g of tea,then vortexed by a vortexer vigorously for 2 min and centrifuged for 5 min at 5000 r/min;（2） 1 mL of supernate was mixed with PSA（25 mg）,GCB（7.5 mg）,MgSO4（150 mg）,then vortexed for 2 min and centrifuged for 5 min（5000 r/min）;（3） the whole procedure was completed within 0.5 h;（4） the solvent of the supernate was substituted by n-hexane,then injected into GC-μECD.The results showed no matrix peaks disturbed the targets＇.The recovery,RSD.and LOQ of the modified DSPE could meet the demand of EU＇s and Japanese for the determination of pesticide residues in tea.The results from real samples analyzed by this method were accordance with those by the authenticated method with SPE purification.

关 键 词：分散固相萃取 茶叶 农药残留 检测 GC-ECD 

分 类 号：O657.7[理学—分析化学]