This International Standard specifies a method for the determination of dissolved fraction of glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), in drinking water, ground water, and surface water at concentrations of 0,03 µg/l to 1,5 µg/l. It does not apply to marine or salty water. This method can be applicable to other types of waters, provided the method is validated for each case.