A CORRECTION TO THE CALCULATION OF THE GIBBS FREE-ENERGY OF ADSORPTION FOR BIOMOLECULES IN ION-EXCHANGE SYSTEMS

We wish to propose a correction to the methodology introduced by Gerst ner et al. [J.A. Gerstner, J.A. Bell, S.M. Cramer, Biophys. Chem. 52 ( 1994) 97-106] for the calculation of Gibbs free energies of adsorption of biomolecules to ion-exchange systems, Our approach is based on the requirement that the mobile phase and stationary phase concentrations be expressed in exactly the same units and the equilibrium constant b e strictly dimensionless. The Gibbs free energies of ion-exchange calc ulated based on this correction appear to be more negative than those originally calculated by Gerstner et al. (C) 1997 Elsevier Science B.V .