Preparation And Properties Of Novel Chiral Stationary Phases On Polysaccharide Derivatives

Nowadays,polysaccharide,as an environmentally friendly renewable resource,has received more and more attention and been investigated extensively by both academic and industrial researchers,due to the increasing scarcity of fossil resources and the environment caused by chemical synthetic materials have become increasingly prominent.The derivatives of the two natural polysaccharides,chitin and konjac glucomannan,were synthesized by chemical modification and their potential application in chiral separation field was discussed in this thesis.The main content and conclusions of this work are as follows.(1)Quaternized chitin chiral stationary phases(QCCSP)were prepared and used as stationary phase for HPLC separation of 13 chiral compounds,toluidine as well as benzene,naphthalene and anthracene.Quaternized chitin(QC)with different degree of substitution and different molecular weight were homogeneously synthesized using(2,3-Epoxypropyl)trimethyl ammonium chloride(EPTAC)as etherification reagent in 8 wt% NaOH /4 wt% urea solution.The cationic quaternized chitin chiral stationary phases(QCCSP)were prepared after QC coated on the surface of spherical silica gels.The results showed that some amino chiral samples were be separated on QCCSP in the normal phase chromatography mode and the QC stationary phase with higher substitution degree showed relatively good separation performance,among which QCCSP4 with the highest degree of substitution(0.89)could sepearate 7 racemates.At the same time,the QC with large molecular weight and relatively regular structure of molecular chain exhibits relatively good chiral recognition ability.The position isomers of toluidine can be properly separated on QCCSP,for instance the highest resolution of meta-toluidine and o-toluidine was 4.91.In addition,the mixture of benzene,naphthalene and anthracene can also be separated on QCCSP.(2)The acrylamide chitin chiral stationary phase(AMCCSP)was prepared and used as stationary phase for HPLC separation of 16 chiral compounds,toluidine as well as benzene,naphthalene and anthracene.The acrylamide chitin(AMC)was also be synthesized in NaOH/urea-aqueous homogeneous system with acrylamide as etherifying agent.The coated AMCCSP was prepared using spherical silica gel as carrier.The chromatographic test results showed that 10 racemates were properly separated on AMCCSP.Moreover,AMCCSP showed good resolution performance for o-toluidine and m-toluidine with resolution of 2.96,and benzene,naphthalene,anthracene can also be separated from baseline on this chiral stationary phase.(3)The konjac glucomannan-3,5-dimethyphenyl carbamate chiral stationary phase(KGMCSP)was prepared and used as stationary phase for HPLC separation of 13 chiral compounds,toluidine as well as benzene,naphthalene and anthracene.The konjac glucomannan-3,5-dimethylphenyl carbamate(KGMMPC)was synthesized under the condition of anhydrous oxygen-free using konjac glucomannan(KGM)as the raw material.And the coated KGMCSP was prepared using spherical silica gel as substrate.The results indicated that KGMCSP showed considerable chiral recognition ability to all the racemates tested and six of them can be separated from the baseline in the normal phase mode.KGMCSP can also effectively separate the isomers of o-toluidine and mtoluidine with resolution of 2.20.In addition,benzene,naphthalene and anthracene can also be partly separated on KGMCSP with resolution of 0.9 and 1.24 respectively.