title: Linear isotherm determination from linear gradient elution experiments.
abstract: A procedure to estimate equilibrium adsorption parameters as a function of the modifier concentration in linear gradient elution chromatography is proposed and its reliability is investigated by comparison with experimental data. Over the past decades, analytical solutions of the so-called equilibrium model under linear gradient elution conditions were derived assuming that proteins and modifier molecules access the same fraction of the pore size distribution of the porous particles. The present approach developed in this work accounts for the size exclusion effect resulting in different exclusions for proteins and modifier. A new analytical solution was derived by applying perturbation theory for differential equations, and the 1st-order approximated solution is presented in this work. Eventually, a turnkey and reliable procedure to efficiently estimate isotherm parameters as a function of modifier concentration from linear gradient elution experiments is proposed.
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Bioscience, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Pfister
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Bioscience, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Fabian
authors.initials: F
authors.lastname: Steinebach
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Bioscience, ETH Zurich, 8093 Zurich, Switzerland. Electronic address: massimo.morbidelli@chem.ethz.ch.
authors.forename: Massimo
authors.initials: M
authors.lastname: Morbidelli
mesh_terms: D000327:Adsorption; D002845:Chromatography / Q000379:methods*; D008956:Models, Chemical; D016062:Porosity; D011506:Proteins / Q000737:chemistry
chemical_list: D011506:Proteins
keywords: Chromatography model; Exclusion effect; Linear gradient elution; Parameter estimation