Characterization and modeling of monolithic stationary phases: applicationto preparative chromatography

A methodology for characterizing and modeling preparative separations on mo nolithic ion-exchange stationary phases is presented. A dimensionless group analysis was carried out to determine the relative importance of mass tran sfer and kinetic resistances on this stationary phase. In contrast to conve ntional beaded morphologies, the continuous bed stationary phase was found to possess enhanced mass transport properties resulting in kinetic resistan ce as the dominant non-ideality. Accordingly, a reaction-dispersive steric- mass action formalism was successfully utilized for simulating preparative displacement chromatography on this resin. Since kinetics were found to be important on this column morphology, mobile phase salt concentration was fo und to be an important variable during displacement chromatography on this stationary phase. An increase in the mobile phase salt concentration was fo und to significantly improve the displacement separation of a model protein mixture. The formalism presented in this paper provides a better understan ding of preparative chromatography in monolithic resin systems and a means of simulating separations on this class of chromatographic stationary phase s. (C) 2001 Elsevier Science B.V All rights reserved.