High-performance liquid chromatographic determination of glyphosate and (aminomethyl)phosphonic acid in human serum after conversion into p-toluenesulphonyl derivatives

We have developed a simple, highly sensitive and fast assay method for determining glyphosate and its major metabolite, (aminomethyl)phosphonic acid (AMPA), in serum by high-performance liquid chromatography with ultraviolet detection. Both compounds were successfully extracted with an anion-exchange resin column and allowed to react with p-toluenesulphonyl chloride. The detection limits were 0.3 microgram/ml for glyphosate and 0.2 microgram/ml for AMPA. Recoveries of glyphosate and AMPA spiked to serum were ca. 75% and ca. 88%, respectively. We are convinced that this procedure, in practice, allows medical examiners to analyse both compounds in the serum of poisoned patients within a short time.