Analytical limitations make it challenging to develop
effective
methodologies for understanding glyphosate-based herbicide levels
in drinking water and groundwater. Due to their lack of chromophores
and zwitterionic nature, glyphosate-based herbicides are difficult
to detect using traditional methods. This paper offers a straightforward
method for quantifying glyphosate, glufosinate, and aminomethylphosphonic
acid (AMPA) via 9-fluorenylmethylchloroformate (FMOC-Cl) pre-column
derivatization and analysis by liquid chromatography with tandem mass
spectrometry (LC–MS/MS). Method development was focused on
optimizing the critical variables for optimal derivatization using
a 24-factorial design. We found that complete derivatization
significantly depends on the inclusion of borate buffer to create
the alkaline conditions necessary for aminolysis. Ethylenediaminetetraacetic
acid (EDTA) addition was critical to minimize metallic chelation and
ensure reproducible retention times and peaks. However, EDTA concentrations
≥5% decreased peak intensity due to ion suppression. The FMOC-Cl
concentration and derivatization time exhibited a direct proportional
relationship, with the complete reaction achieved with 2.5 mM FMOC-Cl
after 4 h. Concentrations of FMOC-Cl greater than 2.5 mM led to the
formation of oxides, which interfere with the detection sensitivity
and selectivity. Desirable results were achieved with 1% EDTA, 5%
borate, and 2.5 mM FMOC-Cl, which led to complete derivatization after
4 h.