Potentiometric Analysis of a Reaction System of Organic Acids

A new potentiometric titration method for the quantitative analysis of a reaction system of diprotonic organic acids is presented. The method uses the individual potentiometric titration data for calculating the dissociation constants. With this information a set of “n – 1” linear equations and “n – 1” unknowns is solved; “n” is the number of organic acids present in the reaction mixture. This method was applied to tartaric acid process production from maleic acid. In this process two successive reactions take place: firstly the maleic acid epoxydizes to epoxysuccinic acid and secondly the epoxysuccinic acid hydrolyzes to tartaric acid, leaving three organic acids present in the reaction system. It is necessary to quantify the concentration of all three acids in order to determine the progress of the reaction. This paper describes a fast, economical and easy to carry out analytical method for determining the concentration of all three acids simultaneously by potentiometric titration.