A generalized theoretical model for the measurement of effective diffusion coefficients of heterovalent ions in macroporous ion-exchange resins by the zero-length column method was developed. The model includes the resistance to mass transfer both in the particle and in the film and described ion fluxes with Nernst-Planck equations. Equilibrium was described using the Langmuir type empirical equation. The values of intraparticle diffusivity of Cu2+, Cd2+ Zn2+, and H+ on commercial Lewatit TP-207 were obtained by non-linear regression, these values agree fairly well with data reported previously in literature. The following trend was observed: D-Cu > D-Zn > D-Cd. (c) 2005 Elsevier Ltd. All rights reserved.