超高效液相色谱-串联质谱法测定茶叶中三种农药残留

Determination of Three Pesticide Residues in Tea by Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry

建立超高效液相色谱-串联质谱法同时测定茶叶中敌敌畏、乐果和喹硫磷残留的分析方法。样品粉碎后用乙腈提取,经Cleanert TPT萃取柱净化,旋蒸,乙腈+水(3+2)定容。用0.1%甲酸(A)、乙腈(B)作为流动相进行梯度洗脱,通过UPLC-MS/MS多反应监测模式(SRM)测定,外标法定量。方法在10~600μg/L质量浓度范围内展示出良好的分离度,线性相关系数均大于0.99。在0.01~0.4 mg/kg添加范围内平均回收率在68.7%~114.9%之间,相对标准偏差(n=6)在2.7%~10.8%之间。乐果、敌敌畏和喹硫磷的方法定量限SLOQ分别为0.005 3, 0.007 3和0.002 7 mg/kg。结果表明,此方法简单快捷、线性相关性好、灵敏度高,可满足同时检测茶叶中上述3种农药的要求。

An analytical method for the determination of dichlorvos, dimethoate and quinalphos pesiticidues residues in tea was established based on ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). The crushed samples were extracted with acetonitrile, purified by Cleanert TPT extraction column, rotary evaporation, and fixed to volume with acetonitrile+water(3+2). Gradient elution was carried out using 0.1% formic acid(A) and acetonitrile(B) as mobile phases. The pesiticidues residues level of dichlorvos, dimethoate, and quinalphos were detected by UPLC-MS/MS on multiple reaction monitoring(SRM) mode and quantified with external standard method. The method showed good separation degree in the concentration range of 10-600 μg/L, and the linear correlation coefficient was greater than 0.99. In the spiked of 0.01-0.40 mg/kg, the average recovery rates measured by external standard method was in the rage of 68.7-114.9%, and the relative standard deviation(n=6) was in the rage of 2.7%-10.8%. The limit of quantitation SLOQ for dimethoate, dichlorvos and quinalphos were 0.005 3, 0.007 3 and 0.002 7 mg/kg, respectively. The results showed that the method was simple and fast,with good linear correlation and high sensitivity. And it could meet the requirements of simultaneous detection of these three pesticides in tea.