Inverse polarography with stationary amalgam anodes: Basic principles and technique

A new method of electrochemical analysis has been devised in which the metallic ions present in an electrolyte are discharged into a mercury cathode. The amalgam electrode so formed is then combined with a standard reference electrode in a suitable dissolution medium and the cell thus produced is allowed to supply current against an opposing voltage set up on a potentiometer. By decreasing the potentiometer voltage in stages a curve of current against potential can be constructed for the dissolution of the amalgam anode; in this curve each metal gives rise to a characteristic wave from the height of which the amount of metal originally present can be derived. Although the method is not so universally applicable as the conventional polarographic technique with the dropping mercury cathode, it possesses advantages in sensitivity and simplicity in suitable cases and may form a useful complementary method of analysis.