Effect of intraparticle convection on the chromatography of biomacromolecules

The effect of intraparticle convection in chromatographic columns packed with gigaporous particles (i.e., where dpore/dparticle > 10(-2)) on the band spreading of unretained biomacromolecules is investigated both experimentally and theoretically. A model is developed for the analysis of mass transfer in spherical particles of bidisperse pore structure when both convection and diffusion take place in the larger pores but only diffusion occurs in the smaller pores. The predictions of the model were experimentally verified. It is demonstrated that gigaporous particles have advantages over conventional porous particles (i.e., where dpore/dparticle < 10(-3)) for applications that do not require high resolving power, to bring about fast separation. This is because columns packed with gigaporous particles can be operated at high flow velocities without significant loss of efficiency due to the enhancement of mass transfer by intraparticle convection. The results of the model are used to examine the effectiveness of gigaporous column packings for rapid analytical chromatography and for the concentration and recovery of a dilute solute in a saturation-regeneration cycle utilizing frontal chromatography.