Ion chromatography of anions: Ion exchange of weak acids on strongly basic anion exchangers

A physicochemical and mathematical model of ion exchange in the system of an aqueous solution of a salt of a weak dibasic acid and a strongly basic anion exchanger is proposed. Numerical calculations are carried out with an example of carbonate solutions, which are commonly used as eluents in ion chromatography, Parameters characterizing the composition of the solution and the ion-exchanger are introduced. It is demonstrated that as the ion exchanger is filled with the dissociation products of a dibasic acid, the fraction of the single-charged ion in the adsorbent varies monotonically, and the fraction of the double-charged anion goes through a maximum.