| Chiral pharmaceutical compounds possess different biological,efficacy,toxicity,transporting,metabolic properties,the research of chiral drugs have become one of the new directions of international drug research.The technique of chiral drug research was finally to establish efficient chiral analysis method.Capillary electrochromatography(CEC),which combines the high efficiency of CE and the high selectivity of HPLC,exhibits great performance in chiral separation and has been extensively used.Open-tubular capillary electrochromatography(OTCEC),an important branch in CEC,provides advantages of ease of preparation,absence of bubble formation,and simple instrumental handling.But in OTCEC,superficial area of the inner face wall is small,and the amount of coating stationary phase is limited,resulting in relatively poor phase ratio and sample separation efficiency.Therefore,increasing the phase ratio as well as the phase ratio and its capacity was the urgent problem for the preparation of OTCEC columns.Gold nanoparticles(GNPs)have their special characteristics of large specific surface area,easy formation of active complexes,and controllable particle size with narrow size distribution.They could compensate the lack mentioned above for OTCEC,and widen the application of OTCEC.β-CD and derivatized β-CDs,which were most widely used as chiral selectors in CE.GNPs will be modified by β-cyclodextrin derivatives(β-CDs),and these functionalized CD-GNPs are subsequently immobilized on capillaries as stationary phase for chiral separation,which is of great importance for widening the CE separation efficiency.In this thesis,chemical bonding,electrostatic adsorption and sol-gel method will be applied for preparing the GNPs/β-CD modified OTCEC columns.Utilizing these prepared OTCEC columns,enantioseparation systems of various kinds of chiral drugs will be established.The research contents are as follows:1.Preparation of GNPs/β-CD modified OTCEC column by chemical bonding and its applicationA new OTCEC column was prepared by chemically immobilized GNPs/β-CD onto new surface of prederivatised fused-silica capillary.Then,the work was focused on the the enantiomeric separations of 10 chiral compounds,including zopiclone,chlorphenamine maleate,brompheniramine maleate,dioxopromethazine hydrochloride,carvedilol,homatropine hydrobromide,homatropine methylbromide,venlafaxine,sibutramine hydrochloride and terbutaline sulfate.The influences of BGE(mobile phase)pH and the concentration of β-CD additive on the enantioseparation efficiency were examined.Finally,the stability and repeatability of the columns were investigated and the possible.separation mechanism was discussed.2.Preparation of GNPs/β-CD modified OTCEC column by layer-by-layer self-assembly and its applicationA novel chiral OTCEC column was fabricated through layer-by-layer self-assembly of GNPs/β-CD onto the new surface of prederivatised fused-silica capillary.Monolayer as well as mutilayer GNPs films capillary columns were prepared.The performance of the monolayer and mutilayer GNPs/β-CD coated OTCEC capillary column was evaluated by chiral separation of meptazinol and its three intermediate enantiomers(intermediates Ⅱ-Ⅳ).As a result,three layer GNPs films capillary columns showed better enantioselectivity.Effect of GNPs layers,organic modifier,buffer pH,applied electric field strength on enantioseparation were examined.Based on which,the optimal separation condition is obtained.Finally,the stability and repeatability of the columns were investigated and the possible separation mechanism was discussed.3.Preparation of β-CD-GNPs modified OTCEC column by electrostatic adsorption method and its applicationFirstly,mono-6-SH-β-CD modified GNPs(β-CD-GNPs)was synthesized and characterized.The novel β-CD-GNPs modified OTCEC column was fabricated by electrostatic adsorption.The novel column was evaluated by chiral separation of five enantiomers(zopiclone,carvedilol,salbutamol,terbutaline sulfate,phenoxybenzamine hydrochloride).After investigating the effect of capillary inner diameter,β-CD-GNPs concentration,β-CD-GNPs concentration coating time,organic modifier,buffer concentration,mobile phase pH and applied electric field strength on enantioseparation.The optimum separation conditions were obtained.Finally,the stability and repeatability of the columns were investigated and the possible separation mechanism was discussed.4.Preparation of β-CD-GNPs modified OTCEC column by sol-gel method and its applicationA novel chiral OTCEC column was fabricated through lsol-gel method.The novel column was evaluated by chiral separation of four enantiomers(chlorphenamine,brompheniramine,pheniramine,zopiclone).After investigating the effect of capillary inner diameter,β-CD-GNPs concentration coating time,mobile phase pH,buffer concentration and organic modifier concentration on enantioseparation.The optimum separation conditions were obtained.Finally,the stability and repeatability of the columns were investigated and the possible separation mechanism was discussed.5.Preparation of GNPs/β-CD modified OTCEC column by chemical bonding and its applicationFirstly,a novel mono-thiol-carboxymethyl-β-cyclodextrin(6-SH-CM-β-CD)was synthesized and characterized by TLC、IR、NMR、MS.A new OTCEC column was prepared by chemically immobilized GNPs/CM-β-CD onto new surface of prederivatised fused-silica capillary.Monolayer,two-layer as well as mutilayer GNPs films capillary columns were prepared.After evaluating the separation efficiency of different layer GNPs/CM-β-CD coated OTCEC capillary column towards four chiral analytes(Compound A,Compound B,tramadol hydrochloride,zopiclone),the two-layer GNPs/CM-β-CD coated OTCEC capillary column was adopted.The effect of GNPs/CM-β-CD coating concentration,mobile phase pH,buffer concentration and organic modifier concentration on enantioseparation were examined and optimized.The optimum separation conditions were obtained.Finally,the stability and repeatability of the columns were investigated and the possible separation mechanism was discussed. |
PDF Full Text Request