超高效液相色谱串联质谱法测定茶叶中的草铵膦、草甘膦及其代谢物

Determination of Glufosinate-ammonium,Glyphosate and its Metabolites in Tea by UPLC-MS/MS Method

目的:建立了茶叶中草铵膦、草甘膦及其代谢物含量的超高效液相色谱串联质谱法。方法:样品以水做提取溶剂,用饱和醋酸铅溶液、二氯甲烷、C18固相萃取柱分别去除茶叶中多酚类物质、生物碱以及色素等小极性杂质,与9-氯甲酸芴甲酯(FMOC-Cl)衍生反应后,用超高效液相色谱串联质谱法测定。结果:草铵膦、草甘膦及其代谢物在0.005~0.4μg/m L浓度范围内线性关系良好;在不同添加水平下,铁观音、红茶、绿茶的加标水平回收率均在90.6%~93.8%之间,相对标准偏差为0.249%~3.01%。结论:该方法简便准确、可用于茶叶中的草铵膦、草甘膦及其代谢物含量的测定。

Objective： To establish a method to determine the content of glufosinate-ammonium, glyphosate and its metabolites in teas by UPLC-MS/MS method. Method： The samples were extracted with deionized water, the impurities in extraction were removed by adding saturated lead acetate solution, dichloromethane, then purified solution was puried through C18 solid phase extraction column. A procedure of chemical reaction of the analytes was performed by adding FMOC-Cl solution. The reduction compounds were puried with dichloromethane. UPLC-MS/MS was used to identify and quantify the analytes. Results： In the range of 0.005-0.4 μg/m L, good linearity was obtaine. The recoveries for Tieguanyin, black tea, green tea samples at different fortified levels range from 90.6 %-93.8 % with relative standard deviations（RSDs） of 0.249 %-3.01 %. Conclusion： This method is simple and accurate, which could be used for detecting glufosinate-ammonium, glyphosate and its metabolites in teas.