Development and validation of rapid technique for trace level quantification of glyphosate and AMPA in water using LC-TQ MS

Glyphosate, an age-old herbicide has now become an emerging concern to mankind because several case reports are there regarding the presence of this contaminant in different water resources along with its toxic metabolite, aminomethylphosphonic acid (AMPA). Furthermore, the International Agency for Research on Cancer (IARC) categorized glyphosate as “probably carcinogenic to humans” in 2015. In this scenario, a validated mass confirmatory method using the Agilent 6470 LC/TQ instrument has been developed to detect and quantify these contaminants at μg L⁻¹ levels in water. The proposed method includes the usage of only one mL of the water sample, a 30-min derivatization step with 9-FMOC-Cl [(9H-Fluoren-9-yl)methyl carbonochloridate], and clean up with dichloromethane (DCM). The developed method is time-saving and less laborious than the conventional methods for the analysis of the contaminants in water. The method validation parameters, like linearity, selectivity, accuracy, and intermediate precision, are satisfactory. Method LOQ (Limit of quantification) for glyphosate-FMOC and AMPA-FMOC was 0.05 μg L⁻¹ and 0.5 μg L⁻¹, respectively. The method can be used for routine monitoring of glyphosate and AMPA residues at very low level in different kinds of water like drinking water, packaged drinking water, irrigation water etc.