Advanced Liquid Chromatography with Tandem Mass Spectrometry Method for Quantifying Glyphosate, Glufosinate, and Aminomethylphosphonic Acid Using Pre-Column Derivatization

Analytical limitations make it challenging to developeffectivemethodologies for understanding glyphosate-based herbicide levelsin drinking water and groundwater. Due to their lack of chromophoresand zwitterionic nature, glyphosate-based herbicides are difficultto detect using traditional methods. This paper offers a straightforwardmethod for quantifying glyphosate, glufosinate, and aminomethylphosphonicacid (AMPA) via 9-fluorenylmethylchloroformate (FMOC-Cl) pre-columnderivatization and analysis by liquid chromatography with tandem massspectrometry (LC-MS/MS). Method development was focused onoptimizing the critical variables for optimal derivatization usinga 2(4)-factorial design. We found that complete derivatizationsignificantly depends on the inclusion of borate buffer to createthe alkaline conditions necessary for aminolysis. Ethylenediaminetetraaceticacid (EDTA) addition was critical to minimize metallic chelation andensure reproducible retention times and peaks. However, EDTA concentrations & GE;5% decreased peak intensity due to ion suppression. The FMOC-Clconcentration and derivatization time exhibited a direct proportionalrelationship, with the complete reaction achieved with 2.5 mM FMOC-Clafter 4 h. Concentrations of FMOC-Cl greater than 2.5 mM led to theformation of oxides, which interfere with the detection sensitivityand selectivity. Desirable results were achieved with 1% EDTA, 5%borate, and 2.5 mM FMOC-Cl, which led to complete derivatization after4 h. The study presents a robust techniqueto detect glyphosate,enhancing comprehension of their effects on the environment and humanhealth.

Automated summary

This study presents a method using FMOC-Cl pre-column derivatization and LC-MS/MS analysis to quantify glyphosate, glufosinate, and AMPA. The optimization of derivatization conditions was conducted and it was found that the inclusion of borate buffer and EDTA addition were critical for complete derivatization. The study provides a robust technique for detecting glyphosate and enhancing understanding of its environmental and human health effects.