The modelling, dynamic behavior, and analysis of affinity and perfusion chromatography systems

Dynamic mathematical models describing multicomponent biospecific adsorption in finite bath and column systems containing either nonporous or porous particles are developed and solutions are obtained for single component systems. In systems containing porous adsorbent particles, dynamic mathematical models are developed in which the effects of macromolecule induced restricted diffusion are considered. Also, a mathematical model describing multicomponent biospecific adsorption in column systems in which perfusion occurs is developed (perfusion is the phenomenon in which mass is transported into porous adsorbent particles by intraparticle convective flow, in addition to pore and surface diffusion). Numerical solutions are obtained for one and two component column systems containing perfusive particles in which there are one or two adsorbing components, and compared with comparable solutions obtained for columns containing purely diffusive particles. The models include the mechanisms of film mass transfer through the viscous layer immediately adjacent to the outer surface of the adsorbent particles, axial dispersion (column systems), pore diffusion (systems contain porous particles), and intraparticle convective flow (systems containing perfusive particles). Dynamic adsorption mechanisms (mechanisms in which the rate of adsorption is finite) as well as equilibrium mechanisms are examined. Results from finite bath systems utilizing two different interaction mechanisms predict identical behavior in the bulk fluid while predicting different concentration profiles of the adsorbate within the particles. Comparing the solutions of column systems containing either perfusive particles or purely diffusive particles indicates that perfusive particles can significantly increase the dynamic uptake and the dynamic separation of the adsorbing species, when the rate(s) of interaction are relatively fast. A new phenomenon, a hump, is observed at smaller times in binary column systems. Analysis suggests that the dynamics of the interaction step play an important role in the formation of the hump --Abstract, page iv