Application of cellulose 3,5-dichlorophenylcarbamate covalently immobilized on superficially porous silica for the separation of enantiomers in high-performance liquid chromatography.

Our earlier studies have demonstrated the applicability of polysaccharide-based chiral selectors in combination with superficially porous (or core-shell) silica (SPS) particles for the preparation of highly efficient chiral stationary phases (CSP). In earlier studies, CSPs were prepared by coating (adsorption) of the chiral selector onto the surface of silica. In this study we report for the first time the CSP obtained by covalent immobilization of a chiral selector onto the surface of SPS particles.

HPLC separation of dihydropyridine derivatives enantiomers with emphasis on elution order using polysaccharide-based chiral columns.

The separation of enantiomers of five chiral dihydropyridine derivatives was studied on five different polysaccharide-based chiral HPLC columns with various normal-phase (NP), polar organic, and reversed-phase eluents. Along with the successful separation of analyte enantiomers, the emphasis of this study was on enantiomer elution order (EEO) with various columns and mobile phase composition. The interesting phenomenon of reversal of EEO, recently reported in the case of amlodipine (AML) depending on the concentration of formic acid in acetonitrile, was also confirmed with NP eluents.