QuEch ERS-LC/MS/MS快速测定不同茶叶中草甘膦、氨甲基膦酸及草铵膦的残留

Fast determination of Glyphosate,Aminomethyl Phosphonic Acid and Glufosinate in different teas by QuEchERS and UPLC/MS/MS

建立了超高效液相色谱-三重四级杆质谱法快速测定不同茶叶中草甘膦、氨甲基膦酸及草铵膦的方法。样品用超纯水提取经二氯甲烷除去其中脂肪,C18粉末萃取净化除杂。以浓度为10mg/mL 9-芴基甲基氯甲酸酯(FMOC-Cl)衍生后,采用5mmoL乙酸铵/0.1%甲酸水和乙腈为流动相进行梯度洗脱,经T3色谱柱分离,UPLC-MSMS测定,同位素内标法定量。本方法定量限为0.1mg/kg,在5-500ng/mL范围浓度时不同茶叶基质中线性系数良好(R2>0.99)。在0.1mg/kg、0.2mg/kg、1mg/kg添加水平下,不同茶叶基质(白茶、红茶、绿茶、花茶、黄茶、普洱茶)中3种化合物回收率在78.8%-104.2%之间,相对标准偏差RSD在1.3%-9.9%之间(n=6)。

A method for the fast determination of Glyphosate,Aminomethyl Phosphonic Acid and Glufosinate in different teas by QuEchERS and UPLC/MS/MS.The samples were extracted with water,defatted using an extraction step with dichloromethane,and cleaned up with C18 sorbent.and then PMG,AMPA and GLUF were derived using 10mg/mL 9-fluorenylmethyl chloroformate(FMOC-CL)in borate buffer.The traget analytes were separated by a waters HSS T3 column with gradient elution using acetonitrile and 5mmol ammonium acetate/0.1%formic acid water,and finally detected with UPLC/MS/MS.Internal standard method was used to determine the results.The limit of quantitation(LQD)of PMG,AMPA,and GLUF were 0.1mg/kg.All pesticide residues studied showed good linearity with correlation coefficient(R^2)greater than 0.99 in the concentration range of 5-500 ng/L.At the spiked levels of 0.1,0.2 and 1mg/kg,the recoveries of PMG,AMPA and GLUF were78.8%-104.2%,and RSDs from 1.3%to 9.9%(n=6).