Stoichiometric mass-action ion-exchange model explicit isotherms for mono-, di-, tri- and tetrameric ions

Abstract

Analytical isotherms for the unhindered stoichiometric mass-action ion exchange of monomeric, dimeric, trimeric and tetrameric ions are derived. The linear increase in oligomer charge from 1 to 4 leads to an exponential increase in the affinity for the stationary phase which, in turn, results in a rapid change in the isotherm shape from hyperbolic to square. The utility of the developed explicit equations is not restricted by the limits imposed by the assumption for absence of steric hindrances because these analytical isotherms can facilitate the use of detailed numerical chromatographic models. © 1995.