Analytical Method Validation for the Determination of Glyphosate in Tea and Soil using LC-ESI-MS/MS and Degradation Dynamics of Glyphosate in Indian Tea Field Ecosystem

An analytical method for the quantitative determination of glyphosate in green tea, made tea, tea liquor and soil was developed and validated using liquid chromatography tandem mass spectrometry. It has been applied to understand the dissipation pattern of glyphosate in tea fields after its application for two seasons. The analytical procedure involved pre-column derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl). Tea and soil samples were collected from tea garden and extracted with aqueous solution of sodium hydroxide followed by pre-column derivatization and analysis by LC-ESI-MS/MS through multiple reaction monitoring (MRM). The recovery of glyphosate was more than 80% when spiked at different levels with a relative standard deviation of less than 10% and coefficient of determination R² ≥ 0.99. The method was reproducible on green tea, made tea, tea liquor and soil with Horwitz ratio (HorRat) <0.5 at 0.1 μg g⁻¹. The confirmation of compound identity was done by using ion ratio.