分散固相萃取净化超高效液相色谱串联质谱法研究茶叶与茶汤中茚虫威残留降解规律  

Study of Indoxacarb Residue Degradation in Tea and Tea Infusion by Ultra High Performance Liquid Chromatography Coupled with Tandem Mass Spectrometry after Dispersive Solid Phase Extraction Cleanup

作　　者：张新忠[1,2,3] 罗逢健[1,2,3] 陈宗懋[1,2,3] 刘光明[1,2,3] 楼正云[1,2,3] 

机构地区：[1]中国农业科学院茶叶研究所农产品质量安全研究中心,浙江杭州310008 [2]农业部茶及饮料植物产品加工与质量控制重点开放实验室,浙江杭州310008 [3]农业部茶叶产品质量安全风险评估实验室,浙江杭州310008

出　　处：《分析测试学报》2013年第1期1-8,共8页Journal of Instrumental Analysis

基　　金：国家自然科学青年基金项目(21107137);国家茶叶产业技术体系项目(CARS-23);农业部农药安全性监测与评价项目

摘　　要：利用分散固相萃取净化茶叶、固相萃取富集净化茶汤,超高效液相色谱串联质谱法测定,建立了茶叶和茶汤中茚虫威残留的分析方法,并研究了150 g/L茚虫威乳油在茶园茶叶中的残留降解规律,对茚虫威在茶叶-茶汤过程中的浸出率和饮用安全性进行风险评估。结果表明:茚虫威在0.01～20.0 mg/L浓度范围内呈线性,其相关系数(r)为0.993 7,仪器检出限(LOD)为0.025 ng,在高、中、低3种水平下的平均加标回收率为96%～107%,RSD(n=6)为1.3%～7.8%,茚虫威在茶鲜叶、成茶中的定量下限(S/N=10)为5μg/kg,茶汤中的定量下限为0.10μg/L;150 g/L茚虫威乳油在茶园鲜叶上的半衰期为1.42～2.47 d;茚虫威在成茶-茶汤过程中的3次总浸出率小于10%,茶汤中茚虫威残留量及浸出率随冲泡次数的增加逐渐下降,按照风险评估制定茶叶中茚虫威残留量MRL值为3 mg/kg是安全的,人体摄入的茚虫威残留量仅占每日允许摄入量(ADI)的0.619%。A convenient and sensitive method for the residue analysis of indoxacarb in tea and tea infusion was developed and validated by using ultra high performance liquid chromatography coupled with tandem mass spectrometry followed by（dispersive） solid phase extraction cleanup.The calibration curve was linear over the concentration range of 0.01-20.0 mg/L for indoxacarb,with a correlation coefficient（r） of 0.993 7,and the limit of detection（LOD） of 0.025 ng.The average recoveries of indoxacarb at three spiked concentration levels in different sample matrixes（made tea,tea infusion and fresh tea leave） ranged from 96% to 107% with relative standard deviations（RSDs,n=6） of 1.3%-7.8%.The limits of quantitation（LOQs） of indoxacarb were 5 μg/kg in tea and 0.10 μg/L in tea infusion,respectively.The proposed method was successfully applied in the degradation and final residue study of 150 g/L indoxacarb emulsifiable concentrates（EC） in the field treatment experiment,and the dissolution dynamic of indoxacarb from made tea to tea infusion was investigated for the risk assessment.The degradation half-life time of indoxacarb in fresh tea leaves was from 1.42 days to 2.47 days.And the total leaching rate of indoxacarb for the brewing processes from made tea to tea infusion for three times was lower than 10%.For the risk assessment,the MRL proposed at 3.0 mg/kg was safety for tea drinking with the pre-harvest intervals（PHI） of ten days.The estimated intake of indoxacarb was shown to be 0.619% of acceptable daily intake（ADI）.

关 键 词：茚虫威 茶叶 茶汤 分散固相萃取净化 超高效液相色谱串联质谱 残留降解规律 

分 类 号：O657.63[理学—分析化学] F767.2[理学—化学]