Two-component irreversible adsorption with pore diffusion control – Experimental verification of a theory for protein adsorption on core–shell resins

Abstract

The adsorption rates of mixtures of BSA monomer and dimer and of fibronectin and thyroglobulin are measured for core–shell adsorbents and compared with a pore-diffusion limited irreversible binding model. Measurements are conducted for individual particles, batch, and packed columns. The proteins in this work are irreversibly bound but have different binding capacities and effective pore diffusivities resulting in different one-component rates. Consistent with the theoretical model, mixture adsorption results in a single adsorption front within the particles, batch uptake curves with no overshoot in the amount adsorbed, and breakthrough curves without roll-up and with the stronger binding dimer emerging first from the column. Quantitatively, the model accounts for the different capacities and diffusivities and for the inert shell through a modified Biot number. Based on one-component measurements, the model accurately predicts mixture adsorption and is useful for describing flow-through purifications where multiple contaminants are removed from an unbound product.