Preparation And Chiral Recognition Ability Of Biselector Polysaccharide-based Chiral Stationary Phases

Polysaccharide derivatives with regular structure and high chiral recognition abilities can be obtained by appropriate derivatization of cellulose and amylose,which have become the most popular materials for preparation of chiral stationary phases(CSPs)for high-performance liquid chromatography(HPLC).Among the polysaccharide derivatives developed so far,phenylcarbamate derivatives of cellulose and amylose exhibited the highest chiral recognition abilities.Traditionally,the polysaccharide-based CSPs for HPLC were prepared based on one derivative.However,the preparation of mixed type CSPs through mixing various derivatives has been very limited.The mixed CSPs including different derivatives bearing different structures may expand the range of the possible resolvable chiral compounds.Based on this idea,the study on the preparation of novel biselector polysaccharide-based chiral stationary phases and their enantioseparation abilities.were performed in this thesis.Firstly,cellulose and amylose phenylcarbamate derivatives with a same substituent were synthesized by conventional carbamoylation.Then monitore the derivatives.Secondly,the coated-type chiral stationary phases(CSPs)for HPLC were prepared by coating method based on the derivatives synthesized in the first step.The obtained polysaccharide-based chiral stationary phases were then mixed to prepare new biselector CSPs.The coating efficiency was analyzed by thermogravimetry analysis(TGA)and the chiral columns were then prepared by the slurry method.Thirdly,nine chiral compounds with typical structures were resolved using the prepared novel biselector polysaccharide-based CSPs by HPLC in order to evaluate the chiral recognition ability of novel biselector polysaccharide-based CSPs.The results show that compared with the traditional single type polysaccharide chiral stationary phase,the chiral recognition ability of the biselector chiral stationary phase prepared in this paper is mostly between the two kinds of single stationary phase.For some chiral compounds,the biselector stationary phase exhibits better chiral recognition than a single stationary phase.The different properties and structure of the different structures and their substituents of the mixed derivatives have a great influence on the chiral recognition ability of the stationary phase.For some enantiomers,the introduction of a derivative with an electron-withdrawing substituent on the benzene ring or the introduction of a derivative having an electron-donating substituent on the benzene ring can increase the chiral recognition ability of the mixed chiral stationary phase,and the chiral recognition ability is gradually enhanced with the increase of the electron-accepting ability of the substituents on the benzene ring in the mixed chiral stationary phase.