ON-COLUMN CHELATION OF METAL-IONS IN CAPILLARY ZONE ELECTROPHORESIS

A method for the chelation of metal ions is described in order to appl y direct UV detection for the determination of these species in capill ary zone electrophoresis. The chelating reaction was carried out on-co lumn by mixing the zones of the reactants during the electrophoretic m igration. The reaction, the stability of the products and the separati on of the products from the chelating agent were investigated by the c helation of metal ions with EDTA. In comparison with a common indirect UV detection method the limit of detection was decreased by a factor of up to 10.