目的：建立应用气相色谱质谱/质谱法(gas chromatography/mass spectrograph/mass spectrograph, GC/MS/MS)同时测定茶叶中茚虫威、溴虫腈和啶虫脒的方法。方法收集吉林省10个市的210份茶叶样品,样品经乙腈提取,氮吹浓缩,固相萃取柱净化,浓缩定容后,采用三重四级杆气质联用仪, MRM测定,对质谱测定的目标离子对进行选择。结果茚虫威、溴虫腈、啶虫脒的质量浓度在0.05~1.0μg/mL范围时,其峰面积与浓度间呈现良好的线性关系,方法的检出限和定量限分别为0.01 mg/kg和0.03 mg/kg,3种农药在3个添加水平下的平均加标回收率为84%~110%,相对标准偏差(relative standard deviation, RSD)≤10.12%。样品中茚虫威的超标率为2.86%,啶虫脒的超标率高达22.86%。结论 GC/MS/MS法的精密度和准确度较好,能够实现茶叶样品中茚虫威、溴虫腈和啶虫脒的同时准确测定。%Objective To establish a method for simultaneous determination of indoxacarb, chlorfenapyr and acetamiprid in tea by gas chromatography/mass spectrograph/mass spectrograph (GC/MS/MS).MethodsA total of 210 tea samples were collected from 10 cities of Jilin province. After extracted with acetonitril, samples were concentrated with blowing nitrogen, and then cleaned up by solid phase exaction, concentrated and constanted volume. And the multiple reaction monitor (MRM) mode was applied for detection by using GC/MS/MS. The target ion pair of mass spectrometry was selected.Results There was a good linear relationship between peak area and concentration of indoxacarb, chlorfenapyr and acetamiprid when their mass concentration ranged from 0.05μg/mL to 1.0μg/mL. The limit of detection (LOD) and limit of quantification (LOQ) of method were 0.01 mg/kg and 0.03 mg/kg, respectively. The average recoveries of the 3 kinds of pesticides in 3 spiked levels were 84%~110%, and the relative standard deviation were lower than 10.12%. The exceeding standard rates of indoxacarb and acetamiprid were 2.86% and 22.86% respectively.Conclusion The GC/MS/MS method is precise and accurate, which can supply a accurate method for the determination of indoxacarb, chlorfenapyr and acetamiprid in tea simultaneously.
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