Coulometric generation of hydrogen ions by oxidation of mercury in (gamma)-butyrolactone and propylene carbonate

The application of mercury for the coulometric generation of hydrogen ions in (gamma)-butyrolactone and propylene carbonate is described. The current–potential curves recorded for this depolarizer, titrated bases, indicator, and the solvents used showed that the investigated depolarizer was oxidized at lower potentials than the oxidation potentials of other components in the solution. The hydrogen ions generated by the oxidation of mercury and the reaction of mercury ions with (gamma)-butyrolactone or propylene carbonate, were used for the titration of organic bases (piperidine, quinoline-8-ol, N,Nʹ-diphenylguanidine, triethylamine, morpholine, urea, butylamine, and (alpha),(alpha)ʹbipyridyl) with visual (Methyl Red as indicator) and potentiometric end-point detection. The relative error of the determination of the bases was about 1%.