Study on determination of glyphosate and aminomethylphosphonic acid in water using hydrophilic-interaction liquid chromatography-tandem mass spectrometry

A method was developed for the determination of glyphosate residues and aminomethylphosphonic acid in water using hydrophilic-interaction liquid chromatography-tandem mass spectrometry( HILIC-MS / MS). The samples were purified with filtration membrane and C 18 solid phase extraction cartridge to remove interfering materials. Glyphosate and aminomethylphosphonic acid were retained and separated on a HILIC column with the mobile phase of 0. 5% isopropylamine and acetonitrile,and finally detected with negative electrospray ionization(-ESI) in multiple reaction monitoring( MRM) mode. The matrix-matched external standard calibration curve were used for quantitative analysis. This method allowed the reproducible and accurate quantification with the concentration range of 10-1000 ng / mL for glyphosate,the calibration curve of aminomethylphosphonic acid showed good linearity in the range of 20-1000 ng / mL,the limits of quantitation( LLOQ) for glyphosate and aminomethylphosphonic acid were 10 ng / mL and 20 ng / mL,respectively. The average recoveries of two drugs at three levels of 50,500 and 1000 ng / mL were between 86. 3% and 102. 7% with RSDs of 2. 3% ~ 9. 1%. The sample pretreatment was successfully carried out without any derivatization. The method,which is easy,fast, sensitive and accurate, can be used to detecte water pollution, and can meet the requirements for the determination of glyphosate and aminomethylphosphonic acid in forensic and clinical analytic toxicology。