UPLC-MS/MS直接进样法测定茶饮料中的吡虫啉和乐果残留

Determination of Imidacloprid and Dimethoate in Tea Beverage by UPLC-MS/MS Direct Injection Method

运用超高效液相色谱-串联三重四极杆质谱仪(UPLC-MS/MS)研究建立一种简便环保、高效准确的用于测定茶饮料中吡虫啉和乐果残留的分析方法。样品经0.22μm滤膜过滤后直接进样测定,色谱柱为Agela Technologies UHP AQ C_(18)(2.1 mm×100.0 mm,1.9μm),以含0.1%甲酸的超纯水和乙腈为流动相梯度洗脱;采用电喷雾离子源(ESI),正离子模式扫描,多反应监测(MRM)模式采集,基质匹配标准工作曲线法定量。结果表明,目标分析物吡虫啉和乐果在2~500μg/L范围内线性关系良好,相关系数R2为0.9965~0.9995;方法检出限(MDL,S/N≥3)为0.0100~0.0333μg/L,方法定量限(MQL,S/N≥10)为0.0200~0.1000μg/L;相对标准偏差(RSD,n=6)<3%;平均加标回收率在93.3%~111.0%之间,RSD(n=3)在0.564%~6.190%之间。该方法简单快速、稳定性好、准确度高,适用于茶饮料中吡虫啉和乐果残留的分析测定。

A simple,environmentally friendly,efficient and accurate method for the determination of imidacloprid and dimethoate in tea beverage by UPLC-MS/MS was developed.The samples were injected directly after filtering by 0.22μm membrane and separated on an UHP AQ C_(18)(2.1 mm×100.0 mm,1.9μm)column in gradient elution mode using a mobile phase gradient elution made up of acetonitrile and 0.1%formic acid water.Analysis on the targets was performed by electrospray ionization mass spectrometry in positive mode.Multiple reaction monitoring(MRM)mode was used for collection,and matrix matched standard curve method was selected for quantitation.The results show that the imidacloprid and dimethoate had good linear relationships in the range of 2~500μg/L,with correlation coefficients R2 between 0.9965 and 0.9995.The MDL(S/N≥3)was 0.0100~0.0333μg/L,while the MQL(S/N≥10)was 0.0200~0.1000μg/L.The relative standard deviation(RSD,n=6)was less than 3%.The average spiked recovery was between 93.3% and 111.0%,with relative standard deviations(RSD,n=3)of 0.564%~6.190%.The method is simple,rapid,replicable and highly stable and suitable for the determination of imidacloprid and dimethoate in tea beverages.