title: Insights into chiral recognition mechanism in supercritical fluid chromatography III. Non-halogenated polysaccharide stationary phases.
abstract: The majority of published enantiomeric separations by supercritical fluid chromatography (SFC) utilize chiral stationary phases (CSP) based on chemically derivatized amylose or cellulose, coated or immobilized on silica. There is a large diversity among these polysaccharide-type CSP enhancing the scope of chiral separation applications. But on the other hand, identifying the appropriate support for a given separation problem is rather difficult. Hence, this study aims to provide insights on the difference and similarity among the non-halogenated polysaccharide CSP in terms of retention and selectivity at a molecular level. Firstly, the potential of the clones provided by different manufacturers is evaluated with carbon dioxide - methanol mobile phases. Then different aspects of the chiral recognition mechanism contributing to the separations on 16 different columns of five distinct chiral selectors will be explored based on a large amount of experimental data acquired with the help of modelling and chemometric techniques. We report the influence of the ligand bonded to the polysaccharide on the non-enantio-specific interactions between the solute and the CSP, comparing phenylcarbamate to 3,5-dimethylphenylcarbamate, and 4-methylphenylester to 3,5-dimethylphenylcarbamate. In addition, we evaluate the impact of the silica treatment on the quality of the separation. The phases are characterized in terms of their retention characteristics assessed by the solvation parameter model and separation capabilities assessed by discriminant analysis.
authors.affiliation: Université d'Orléans, ICOA, CNRS UMR 7311, Pôle de Chimie, rue de Chartres, 45067 Orléans cedex 2, France.
authors.forename: Syame
authors.initials: S
authors.lastname: Khater
authors.affiliation: Bristol-Myers Squibb, PO Box 4000, Route 206 and Province Line Road, Princeton, NJ 08453-4000, United States.
authors.forename: Yingru
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Université d'Orléans, ICOA, CNRS UMR 7311, Pôle de Chimie, rue de Chartres, 45067 Orléans cedex 2, France. Electronic address: caroline.west@univ-orleans.fr.
authors.forename: Caroline
authors.initials: C
authors.lastname: West
mesh_terms: D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D011134:Polysaccharides / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D011134:Polysaccharides
keywords: Chiral recognition; Linear solvation energy relationship (LSER); Polysaccharide-based chiral stationary phases; Quantitative structure–retention relationships (QSRR); Solvation parameter model; Supercritical fluid chromatography