Determination of glyphosate and aminomethylphosphonic acid by capillary electrophoresis with indirect detection using pyridine-2,6-dicarboxylic acid or 3,5-dinitrobenzoic acid

摘要

Glyphosate (GlyP), a widely used nonselective herbicide, and aminomethylphosphonic acid (AMPA), GlyP's most common product of degradation in the environment, seem not to pose any major health threats. However, due to their persistence and the large quantities applied worldwide, they have become a source of concern. This justifies that their simple and swift determination is of considerable relevance. This work presents two indirect capillary electrophoretic methodologies using as chromophores 3,5-dinitrobenzoic acid (DNB) and pyridine-2,6-dicarboxylic acid (PDC), both associated with hexadecyltrimethylammonium bromide (CTAB). Although both methods showed suitable analytical parameters, DNB evidenced to be slightly superior. The recoveries values were close to 100%, correlation coefficients were above 0.99 and the limits of detection (LODs) values were below 0.5mg L-1 (2.9 mu mol L-1) and 0.4mg L-1 (3.6 mu mol L-1) for GlyP and AMPA, respectively.