Determination of Glyphosate and Its Metabolite, (Aminomethyl)phosphonic Acid, in River Water

Abstract

Abstract A procedure for extracting glyphosate and its meta bolite, (aminomethyl)phosphonic acid, from river water and for determining these 2 compounds by gas chromatography/ion trap mass spectrometry is described. Both compounds were extracted with Bio-Rad AG 1-X8 anion-exchange resin (formate form) prior to derivatization with a mixture of trifluoroacetic anhydride and trifluoroethanol. Limits of detection for glyphosate and its metabolite were 1 ppb even when as little as 10 mL water was analyzed. Recoveries of both compounds from river water fortified at 50 ppb were >90%.