Differential Pulse Polarographic Investigations on Glyphosate and Glufosinate Herbicides in Relation to Their Environmental Analysis.

Abstract

Differential pulse polarographic (DPP) investigations on the reaction of the amino function of glyphosate and glufosinate herbicides with carbon disulphide and copper(II) perchlorate forming copper(III) dithiocarbamate complexes were made in the presence of sodium perchlorate in acetonitrile at dropping mercury electrode (DME). The newly formed herbicide complexes exhibited analytically useful diffusion-controlled peaks at - 115mV and - 110mV versus saturated calomel electrode (SCE) with linear relationship between current and concentration. This observation formed the basis for the determination of glyphosate and glufosinate in the concentration ranges 0.34-8.45μgmL-1 and 0.4-9.91μgmL-1 respectively with correlation coefficient of 0.999. The method was applied to their determinations in soil, fortified food and spiked water samples to assess their environmental relevance. The recoveries of the herbicides were in the range 89.5%-98.3% with relative standard deviation (RSD) in the ranges 0.8%-1.8% thus showing good accuracy and precision of the method.