PULSED AMPEROMETRIC DETECTION OF METAL-IONS COMPLEXING WITH EDTA IN AFLOW-INJECTION SYSTEM

A general and universal detection method, which can be used in high pe rformance liquid chromatography (HPLC) and flow injection analysis (FI A) system for the determination of any metal ions complexing with ethy lenediaminetetraacetic acid (EDTA), is demonstrated. Pulsed amperometr ic detection scheme is applied in a now-through thin layer electrochem ical cell at an Au working electrode. Fluctuation of peak current leve l at the same flow rate of carrier solution is minimized at this solid working electrode, whereas not at a dropping mercury electrode. Remov al of dissolved oxygen can be omitted with this detection method, whic h is a required step for cathodic detection methods. Also, a group of metal ions can be determined selectively and indirectly with this dete ction scheme.