The coulometric titration of 20–200 μeq of acids and bases in DMSO media is described. In the titration of bases, the electro-oxidation of hydrogen at a platinized platinum electrode is used as the source of protons. The conditions for 100 % current efficiency at this electrode are low current density to avoid passivity and regular treatment of the electrode with potassium dichromate—sulfuric acid to remove a poisoning sulfide layer. The accuracy of the titrations is better than ±1 %. Very weak acids like phenols (pKa (DMSO) ≈16) can be titrated successfully. Tris(hydroxymethyl)aminomethane is the weakest base titrated.
Bos, M., IJpma, S. T., & Dahmen, E. A. M. F. (1976). The coulometric titration of acids and bases in dimethylsulfoxide media. Analytica chimica acta, 83, 39-47. https://doi.org/10.1016/S0003-2670(01)84629-8