title: Determination of adsorption isotherms in supercritical fluid chromatography.
abstract: In this study we will demonstrate the potential of modern integrated commercial analytical SFC-systems for rapid and reliable acquisition of thermodynamic data. This will be done by transferring the following adsorption isotherm determination methods from liquid chromatography (LC) to supercritical fluid chromatography (SFC): Elution by Characteristic Points (ECP), the Retention Time Method (RTM), the Inverse Method (IM) and the Perturbation Peak (PP) method. In order to transfer these methods to SFC in a reliable, reproducible way we will demonstrate that careful system verification using external sensors of mass flow, temperature and pressure are needed first. The adsorption isotherm data generated by the different methods were analyzed and compared and the adsorption isotherms ability to predict new experimental elution profiles was verified by comparing experiments with simulations. It was found that adsorption isotherm data determined based on elution profiles, i.e., ECP, IM and RTM, were able to accurately predict overloaded experimental elution profiles while the more tedious and time-consuming PP method, based on small injections on concentration plateaus, failed in doing so.
authors.affiliation: Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Enmark
authors.forename: Patrik
authors.initials: P
authors.lastname: Forssén
authors.forename: Jörgen
authors.initials: J
authors.lastname: Samuelsson
authors.forename: Torgny
authors.initials: T
authors.lastname: Fornstedt
mesh_terms: D000327:Adsorption; D000983:Antipyrine / Q000032:analysis / Q000737:chemistry; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D000432:Methanol / Q000737:chemistry; D008956:Models, Chemical; D011312:Pressure; D015203:Reproducibility of Results; D013816:Thermodynamics
chemical_list: D000983:Antipyrine; D000432:Methanol
keywords: Adsorption isotherms; Elution by Characteristic Points; Inverse Method; Perturbation Peak method; Retention Time Method; Supercritical fluid chromatography