高效液相色谱串联质谱测定武夷岩茶中草甘膦残留量的方法探讨

摘要

A method for determination of glyphosate residues in Wuyi rock tea was developed using high performance liquid chromatography tandem mass spectrometry method. The procedure is as follow,the glyphosate were extracted with water from samples, and purified using TPT. Then derivatization reaction was done in borate buffer with fluorenylmethylchloroformate(FMOC - Cl). Using 1% solution of ammonium acetate and acetonitrile as the mobile phase, mass spectrometry using electrospray ionization in positive ionization mode and multiple reaction monitoring mode. The results showed that the linear correlation coefficient r = 0. 998 when glyphosate is between1ng - 10ng/ mL. Wuyi blank samples were used in added recovery experiment at four spiked levels(n = 5),the average recovery of glyphosate were 87. 3% to 98. 0% . The relative standard deviation(RSD)were 3. 46 to 5. 12.%采用高效液相色谱串联质谱建立了武夷岩茶样品中草甘膦的残留量的测定方法。样品经水固相萃取和茶叶专用萃取柱（TPT）净化后，在硼酸盐缓冲液中与9-芴甲基氯甲酸酯（FMOC - Cl）进行衍生化反应，以1％乙酸铵溶液和乙腈为流动相，质谱检测采用电喷雾正离子化模式和多反应监测模式。结果表明，草甘膦在1~10 ng/ mL 范围内线性良好，线性相关系数 r =0.998。通过对空白武夷岩茶样品进行4个加标水平的添加回收实验（n =5），草甘膦的平均回收率和相对标准偏差（RSD）分别为87.3％~98.0％和3.46~5.12。