Simultaneous determination of glyphosate, glufosinate, and aminomethylphosphonic acid by capillary electrophoresis after 9-fluorenylmethyl chloroformate derivatization

A capillary electrophoresis (CE) with UV absorption detection method is described for the simultaneous determination of glufosinate, glyphosate, and aminomethylphosphoric acid. The 9-fluorenylmethyl chloroformate (FMOC-Cl) was used for precolumn derivatization of the non-absorbing herbicides. The three analytes were separated by CE in 9 min with 25 mM borate buffer at pH 9, followed by detection with a UV detector at 260 nm. We demonstrate how the detection limit can be enhanced by using acetonitrile-salt mixtures. With acetonitrile-salt mixtures, the limit of detection (LOD) was in the 10(-7) M range. Linearity of more than two orders of magnitude was generally obtained. Precisions of migration times and peak areas were less than 0.9% and 7.5%, respectively. The applicabilities of the method for the analysis of ground water and lake water were examined.