Multi step controlled potential electrolysis:

Determination of various metal ions in the similar solution is possible along with the controlled potential electrolysis by using a mercury pool cathode. A sample solution, containing various metal ions like as Cu²⁺, Bi³⁺, Pb²⁺ and Zn²⁺, might be determined through this technique. While the cathode potential is fixed at ~ 0.008V vs. SCE, Cu²⁺ is decreased to Cu⁰, while the current decays to background value, the potential of the cathode was adjusted to - 0.3V Vs SCE at that Bi³⁺ is reduced to Bi⁰. At last by controlling the potential, Pb2+ could be determined as Pb⁰ and Zn²⁺ as Zi⁰. A sample of brass/bronze which contains Cu²⁺, Zn²⁺ and Pb²⁺ may be analysed through this techniques.