Fast estimation of adsorption isotherm parameters in gradient elution preparative liquid chromatography. I: The single component case

Estimation of Nonlinear Adsorption Isotherms in Gradient Elution RP-LC of Peptides in the Presence of an Adsorbing Additive

“…This study extends our investigation of nonlinear adsorption isotherm determination with the IM in gradient elution [3–6] to the presence of an adsorbing additive. To this end, the adsorption isotherms on CSH stationary phases of two endogenous opioid peptides in the presence of TFA were determined in gradient elution.…”

“…Currently, there is a trend in the biopharmaceutical industry towards improving process understanding and replacing statistical and empirical correlations with mechanistic models [2]. Adsorption isotherm determination is an essential step in the mechanistic modeling of preparative LC and is preferably performed using the inverse method (IM) since it requires little experimental work and small amounts of substance [1, 3, 4]. Recently, we extended the IM to estimation of adsorption isotherm parameters directly from overloaded profiles obtained in gradient elution [3–6].…”

“…Adsorption isotherm determination is an essential step in the mechanistic modeling of preparative LC and is preferably performed using the inverse method (IM) since it requires little experimental work and small amounts of substance [1, 3, 4]. Recently, we extended the IM to estimation of adsorption isotherm parameters directly from overloaded profiles obtained in gradient elution [3–6]. The IM had previously only been used in isocratic elution and it was then cumbersome to determine isotherms for gradient elution since experiments had to be performed at multiple modifier levels in isocratic elution [7].…”

Determination of adsorption isotherms in supercritical fluid chromatography

“…The Perturbation Peak method (PP) is a well-established and frequently used method for adsorption isotherm determination in LC [4,7,[19][20][21][22]. The adsorption isotherm is determined by injecting a small excess or deficiency of the solute into a column that are already equilibrated with an eluent containing identical solute molecules, i.e., a concentration plateau.…”

“…4 the shape of the adsorption isotherms, obtained using ECP, RTM and IM are nearly identical, while the PP results differ significantly. We used the determined adsorption isotherm parameters to simulate the elution profile for a 10,20,30,40 and 50 L injection of 250 g/L antipyrine using the ideal model, these simulations, together with the corresponding experimental elution profiles, is plotted in Fig. 5(a)-(d).…”