Alternative reference electrodes

Two ref. electrodes, Hg(I) sulfate and Pb(I) sulfate, with incorporated Li2SO4 salt bridge, are proposed as alternatives for diffuse electrodes of calomel and silver chloride, in potentiometric monitoring such as pH-metry and pIonometry. With a Li2SO4 salt bridge of 2m, the operating potential of the two ref. electrodes is, resp., EREF[Hg4SO4] = 0.6326 ± 0.0008 V and EREF[PbSO4] = -0.3327 ± 0.0008 V, at 25°.