超高效液相色谱-串联质谱法快速测定茶叶中18种农药残留

Determination of eighteen pesticide residues in tea by ultra-high-performance liquid chromatographytandem mass spectrometry

建立了使用超高效液相色谱-串联质谱快速有效测定茶叶中18种农药残留量的方法。茶叶样品经乙腈提取,Cleanet TPT固相萃取柱净化后,采用UPLCTM HSS T3色谱柱分离,以电喷雾电离、多反应监测模式检测。考察了不同固相萃取柱的净化效果,以及不同配比的乙腈-水和甲醇-水组成的流动相对电离效率、分辨率和灵敏度的影响。通过基质匹配标准曲线进行定量。18种农药在2～200μg/L范围内线性良好,所有农药相关系数R>0.99。目标农药的检出限(LOD)在0.03～0.15μg/kg之间。18种农药在10,50,100μg/kg加标水平下的回收率为70%～109%,相对标准偏差为2.2%～15%。方法已用于茶叶样本测定。

A method for the determination of 18 pesticide residues in tea by ultra-high-performance liquid chromatography-tandem mass spectrometry（UPLC-MS / MS） was developed.The samples were extracted with acetonitrile.The extract was cleaned-up with different solid phase extraction（SPE） columns-Cleanet TPT,ODS C 18,Amino and Florisil column.The separation was performed on a UPLCTM HSS T3 column.Effects of acetonitrile-water and methanol-water with different proportions as mobile phase on the ionization efficiency,resolution and sensitivity were compared.The eighteen pesticides were determined in the modes of electrospray ionization and multiple reaction monitoring.The analytes were quantified by matrix-matched internal standard method.The calibration curves showed good linearity in 2-200 μg / L for each pesticide（R 0.99）.The limits of detection（LODs） were in the range of 0.03-1.5 μg / kg.The recoveries of all the pesticides varied from 70% to 109% with the relative standard deviations of 2.2% ～ 15% at the spiked levels of 10,50,100 μg / kg for all pesticides.The method has been applied to the determination of tea samples from different regions successfully with satisfactory results.