Coulometric generation of H+ ions by the anodic oxidation of esters of gallic acid

Abstract

The application of esters of gallic acid (propyl, butyl and dodecyl gallate) for the coulometric generation of H+ ions in aqueous media is described. The current-potential curves recorded for these depolarizers, as well as for tris(hydrosymethyl)aminomethane ("THAM") and the employed solvent showed that the investigated depolarizes are oxidized at potentials lower than the oxidation potentials of the other components in the solution. The H+ ions formed by the oxidation of these depolarizers (in 1 mol/L sodium perchlorate in water) were used for the titration of THAM with potentiometric end-point detection using a hydrogen/palladium indicator electrode. The current efficiency was 100 %.