Green analysis of glyphosate and its metabolite amino methyl phosphoric acid in tea

Abstract

Objective： This study aimed to develop an ion chromatography-tandem mass spectrometry (IC-MS/MS) for the analysis of glyphosate and its metabolite amino methyl phosphoric acid (AMPA) residues in tea without derivatization. Methods： Tea samples were ultrasonically extracted with 20 mmol/L NaOH aqueous solution and cleaned up by dispersive solid-phase extraction (150 mg primary-secondary amine (PSA), 15 mg C18, 15 mg graphitized carbon black (GCB)). The samples were separated on an ion chromatographic column AS11-HC-4 μm (2 mm×250 mm) by using an isometric elution procedure of 35 mmol/L aqueous solution of sodium hydroxide as mobile phase. A multiple reactions monitoring (MRM) model was used to obtain the sensitivity of the method, and the isotopically labeled internal standards were applied in the calibration process. Good linearities and recoveries were obtained in the validation process. Results: The correlation coefficients R2 were 0.999 8 and 0.998 2, respectively. The detection limits of glyphosate and AMPA in tea were both 0.05 mg/kg, and the quantification limits were both 0.10 mg/kg. The average recoveries of glyphosate and AMPA were 61.2%～104.9% and 61.5%～83.2%, respectively with RSDs less than 20%. Conclusion: This method meets the requirements of green analytical chemistry and can be used for routine detection of glyphosate and aminomethylphosphoric acid residues in tea.

Keywords

• icic-ms/ms
• glyphosate
• amino methyl phosphoric acid
• tea
• green analytical chemistry