Method for determination of glyphosate residues in natural waters based on polarography of the N-nitroso derivative

Abstract

A differential pulse polarographic method for the determination of residues of glyphosate herbicide in natural waters down to 35 µg l^–1 is described. The material is concentrated by chromatography on an anion-exchange column, which at the same time serves as the only clean-up step required. A polarographically active glyphosate derivative is obtained by nitrosation performed directly in a fraction of the eluate from the column. The precision in terms of relative standard deviation varies from 22.8% at the detection limit to 2.3% at 210 µg l^–1. The total analysis time for one sample is 3–4 h.