Protein adsorption on novel acrylamido-based polymeric ion-exchangers III.Salt concentration effects and elution behavior

The effect of salt concentration on the adsorption and desorption of BSA ha s been determined for a polymeric anion-exchanger based on acrylamido monom ers. The material investigated possesses a high adsorption capacity at low salt concentration and the bound protein can be recovered quantitatively at high salt concentrations. The effects of salt on adsorption and desorption rates were evaluated from batch and shallow-bed experiments, and a model w as developed to describe the data quantitatively. The adsorption capacity d ecreases as the salt concentration is increased, but both adsorption and de sorption rates increase at higher salt concentrations. The predictability o f the behavior of columns packed with this material was examined by compari ng model predictions and experimental results obtained in laboratory column s. In general, a good agreement was obtained between predicted and experime ntal breakthrough and elution profiles, especially in shorter columns. Thus , the model allows a prediction of the effects of column length, mobile pha se flow-rate, protein feed concentration, and salt concentration on dynamic capacity, productivity, and on the concentration of product fractions. (C) 2001 Elsevier Science B.V. All rights reserved.