A potentiometric detection technique for chelating agents after separation by capillary zone electrophoresis

The combination of capillary zone electrophoresis with potentiometric detection has been investigated for the determination of chelating agents such as diethylenetriaminepentaacetic acid. The detector consists of a metallic copper electrode with a diameter of 100˜í¬¿m arranged in an end-capillary configuration. The electrode potential depends on the concentration of copper ions at the electrode surface and therefore decreases when chelating agents pass the electrode. In combination with UV detection, both free ligands and metal complexes could be detected.