Pure and Applied Chemistry

Abstract: A new, simplified design and a convenient preparation procedure for the Pb(Hg)|PbSO₄|SO₄^2- electrode are proposed. This procedure ensures preparation of stable amalgams and reproducible electrode potentials, which make this electrode useful and attractive for both thermodynamic investigations and electroanalytical applications. For these purposes, the electrode prepared according to the proposed procedure has been exhaustively characterized both thermodynamically and as a sulfate-sensing electrode, in different sulfate solutions, including H₂SO₄. Also, a practical standardization procedure has been proposed. The Pb(Hg)|PbSO₄|SO₄^2- electrode can be structured with a built-in concentrated Li₂SO₄ salt bridge for use as a sulfate-based reference electrode. This electrode can be operated as a reference electrode alternative to the conventional calomel or Ag|AgCl reference electrodes in electroanalytical practice.