超高效液相色谱串联质谱法测定茶叶中的草甘膦及其代谢物

Determination of Glyphosate and its Metabolites in Tea by UPLC-MS/MS

建立测定茶叶中草甘膦、氨甲基膦酸的液相色谱-串联质谱法。样品用一级水提取,加二氯甲烷去除茶叶中弱极性杂质,离心,取上清液过WondaSep Glyphosate固相萃取柱,流出液在5%硼酸中与9-芴基甲基氯甲酸酯(FMOC-Cl)衍生反应,生成草甘膦-FMOC、氨甲基膦酸-FMOC,过PTFE滤膜,LC-MS/MS正离子扫描测定茶叶中草甘膦、氨甲基膦酸的含量。该方法的线性范围1~50 ng/mL,相关系数>0.999,加标0.05~1.0 mg/kg,回收率为81.7%~101.2%,RSD为1.0%~6.7%,草甘膦、氨甲基膦酸检出限为0.05 mg/kg。结论:该方法灵敏、快速、准确,适用于茶叶中草甘膦及其代谢物的检测。

A method for the determination of glyphosate and aminomethylphosphonic acid in tea was developed by means of a series mass spectrometry(MS)methods.The sample is extracted with first-class water,and dichloromethane is added to remove the weak polar impuritiesin tea,and centrifuged,The supernatant was passed through the wondasep glyphosate solid-phase extraction column,and the effluent reacted with 9-fluorenylmethylchloroformate(FmocCL)in 5%boricacid,Glyphosate Fmocand aminomethylphosphonic acid Fmoc were derived.The contents of glyphosate and amino-methylphosphonic acidin tea were determined by LC-MS/MS positive ion scanning with PTFE membrane.The results showed that the linear relationship of the Pesticides to be tested was good in the range of 1.0 ng/mL to 50ng/mL.and the correlation coefficient(r)was all above 0.999.Addition recovery experiments were conducted at 0.05~1.0 mg/kg concentration levels,the average recovery rate was between 81.7%and 101.2%,and the relative standard deviation ranged from 1.0%to 6.7%.The detection limit of the developed method reached up toGLY0.05mg/kg.AMPA 0.05 mg/kg.The method has high sensitivity,short analysis time and strong corroboration ability,which is recommended to be used in simultaneous determination of Quinolones,tetracyclines and Chloramphenicols residues.