DETERMINATION OF COPPER BY ELECTROTHERMAL AAS AFTER ELECTRODEPOSITIONON A GRAPHITE DISK ELECTRODE

The electrodeposition of copper on a graphite electrode at a constant potential with subsequent atomization in the graphite atomizer HGA-400 has been studied. A special graphite disk electrode is suitable for e lectrochemical enrichment at E = -0.7 V vs. SCE and the determination of copper by electrothermal-atomic absorption spectrometry (ET-AAS) if atomized at 2300 degrees C. In this way copper was determined in pota ble water and free Cu2+ could be distinguished from that bound in chel ate speciations after using a suitable deposition potential of the wor king electrode. This approach seems to be an alternative to the common ly used anodic stripping voltammetry (ASV) for the preconcentration an d determination of free metal ions.