Characterization of Thick-Layer Graphite Disposable Voltammetric Electrodes

Graphite thick-film disposable electrodes which may be used for sensitive analytical determinations by the techniques of conventional and stripping voltammetry have been characterized by electron scanning microscopy, optical spectroscopy, and electrochemical methods. Studies on the reversible Cc^- + e^- ⇌ Cc (Cc is cobaltocene) reduction process in acetonitrile confirmed the inlaid and recessed disk microelectrode random array-type behavior expected at a rough surface on the basis of examination of the electrode surface by electron scanning microscopy. Anodic stripping voltammograms of copper, lead, and cadmium in 0.1 M HCl at an in situ mercury-plated disposable graphite electrode demonstrate the excellent analytical performance that may be achieved for trace analysis even at unusually fast scan rates in the volts per second range. The microelectrode array properties also mean that oxygen removal and stirring of the solution can be avoided when the electrodes are used for stripping voltammetry.