Productivity and operating regimes in protein chromatography using low-molecular-mass displacers

A theoretical and experimental study of ion-exchange displacement chromatography using the low-molecular-mass displacer neomycin sulfate, is carried out. A chromatography model utilizing the steric mass action (SMA) ion-exchange formalism is employed to predict the displacement behavior of proteins displaced by neomycin sulfate. An operating regime plot is developed from the SMA model to predict selective displacement chromatography using low-molecular-mass displacers. Numerical simulations are employed to examine the behavior of selective displacement systems and to investigate the productivity of displacement chromatography. In this study, it is seen that use of low-molecular-mass displacers allows ''selective displacement'' separations in which some impurities are removed by elution or by desorption within the displacer front. Further, low-molecular-mass displacers, like previously studied high-molecular-mass displacers, can provide high productivity chromatographic separations even for feed streams characterized by low separation factors.