Corrosion of platinum electrodes in phosphate buffered saline solution

A high sensitive detection method allows the direct determination of Pt2+/Pt4+ within a concentration range of ng/1 (ppt). The procedure was used to establish the development of soluble platinum species during constant or dynamic polarisation of platinum electrodes in phosphate buffered saline solution. Platinum showed some properties of a passive metal. In the passivated state the dissolution was influenced by a surface film. Furthermore a soluble platinum species was found to be produced during the reduction of the surface oxide. These results confirmed by direct evidence the conclusions of earlier investigations concerning the corrosion of platinum based on electrochemical measurements.