Comparative study of cellulose tris(3-chloro-5-methylphenylcarbamate) coated or covalently immobilized on silica for separation of enantiomers in high-performance liquid chromatography

Author: თამარ ხატიაშვილი
Keywords: separation of enantiomers, covalently immobilized, polysaccharide based chiral selector
Annotation:

Analytical and preparative separation of enantiomers is considered as the most difficult problem in separation science for many years due to identical properties of enantiomers in achiral environment. Only in 1980s chiral columns for high-performance liquid chromatographic (HPLC) separation of enantiomers became commercially available. Among all chiral stationary phases (CSP) available today for HPLC separation of enantiomers polysaccharide based chiral selectors (CS ) are most widely used CS and most commercially available chiral HPLC columns contain polysaccharide based CS. Polysaccharide-based CSPs are commonly prepared by physical coating of polysaccharide derivative onto the surface of silica. On the one hand, this is a quick method that does not require pre-activation of silica. As for covalently immobilized CSs, the main mechanism of immobilization is interconnection of polysaccharide chains. The advantage of this method is that immobilized chiral stationary phases are stable, compatible with different type of mobile phase components and suitable for adjustment of enantiomer elution order. The major research goal of the present thesis is comparison of cellulose tris(3-chloro-5-methylphenylcarbamate) coated or covalently immobilized on silica for separation of enantiomers in methanol and mixture of n-hexane and isopropanol (v/v) as mobile phases. In the frames of the present thesis we also studied enantiomer elution order and described the thermodynamics of chiral separation.