| Relying on the features of automatic operation and high sensitivity,high performance liquid chromatography(HPLC)method has been extensively used.The chiral stationary phase(CSP)is the core of HPLC enantiomeric resolution.In recent years,various types of CSP have emerged endlessly.In this paper literature research on HPLC chiral separation are summarized,are introduced chiral metal-organic framework(MOFs)materials in recent years,and focused on the types of MOFs-based HPLC stationary phases and the research progress in the resolution of chiral compounds.Through the exploration of different valence metal ions,organic ligands,and synthesis methods,?-cyclodextrin(?-CD)and m-carboxybenzenesulfonyl chloride(the organic ligands),and potassium ion(the central metal ion)are used raw material for the synthesis of chiral MOFs.Preparation of?-CD-MOF-P50 by one-pot method and preparation of?-CD-MOF-P20 by vapor diffusion method,two kinds of chiral MOFs with different void structures are constructed.The structure and morphology of?-CD-MOF-P50 and?-CD-MOF-P20 are determined by solid ultraviolet diffuse reflectance spectroscopy,Fourier infrared spectroscopy,X-ray powder diffraction,hydrogen nuclear magnetic resonance spectroscopy,X-ray photoelectron spectroscopy,field emission electron microscopy and optical microscopy.Using?-CD-MOF-P50 and?-CD-MOF-P20 bonded silica as stationary phase fillers,the stationary phase fillers of column 1 and column 2 are characterized by X-ray photoelectron spectroscopy and field emission electron microscopy.The stationary phase based on the target MOFs is successfully prepared.HPLC chiral column 1 and column 2 are prepared by the wet pack method.Five chiral drugs,chlorpheniramine maleate(CM),ornidazole,doxazosin,ranolazine,and dropropizine are used for resolution.Column 1 and 2 are systematically researched from the aspects of mobile phase ratio,buffer solution p H,buffer solution concentration,mobile phase flow rate,etc.Under the best chromatographic conditions for the separation of CM on column 2,the resolution Rs of CM is 5.09.In the racemate concentration range of 1.30×10-4mol/L to 5.19×10-3 mol/L,the peak height and peak area of the two enantiomers of CM show a better linear correlation with the concentration(r respectively:0.9986,0.9992,0.9995 and0.9998).Repeatability investigation(n=7),the RSD of each chromatographic parameter is less than 5%;Under the optimal chromatographic conditions for the separation of ranolazine on column 2,the Rs of ranolazine is 1.52.In the racemate concentration range of 3.0×10-5mol/L to 3.5×10-4 mol/L,the peak height and peak area of the two enantiomers of ranolazine show a better linear correlation with the concentration(r respectively:0.9994,0.9854,0.9915and 0.9997).Repeatability investigation(n=7),the RSD of each chromatographic parameter is less than 2%;Under the optimal chromatographic conditions for the resolution of dropropizine,the Rs of dropropizine is 1.08.Under the optimal chromatographic conditions for the separation of ornidazole on column 1,the Rs of ornidazole can reach 1.90,under the optimal chromatographic conditions for the separation of doxazosin,the Rs of doxazosin can reach 1.51.With chiral pesticides(fenoxaprop-ethyl,fluralaner,quizalofop-ethyl,bifenthrin)as the resolution object,the resolution performance of column 2 are researched.Including optimizing the mobile phase ratio,buffer solution p H,buffer solution concentration,and mobile phase flow rate,the optimal chromatographic conditions for the separation of these chiral pesticides in column 2 are obtained.Under the optimal chromatographic conditions for the resolution of the enantiomers of fenoxaprop-ethyl:The Rs can reach 9.09.The concentration of racemate is in the range of 6.20×10-6 mol/L?2.99×10-4 mol/L,the peak height and peak area of R-fenoxaprop-ethyl and S-fenoxaprop-ethyl is in an excellent linear correlation with the concentration.(r are 0.9967,0.9999,0.9962 and 0.9996,respectively).Repeatability study(n=7),the RSD of each chromatographic parameter is lower than 2%.Under the optimal chromatographic conditions for the separation of the enantiomers of fluralaner,Rs is 1.67.In the range of 9.7×10-5 mol/L?9.67×10-4 mol/L there are better linear correlation between with the peak height and peak area of the two enantiomers and the racemate concentration(r are 0.9999,0.9997,0.9985 and 0.9864,respectively).Reproducibility study(n=7)shows that the RSD of each chromatographic parameter is lower than 8%;Under the optimal chromatographic conditions for the resolution of the enantiomers of quizalofop-ethyl,the Rs is up to 1.88,and the Rs of the enantiomers of bifenthrin is 1.06.The chiral recognition differences between MOFs column 1,column 2 and non-MOFs environmental HPLC chiral column are studied.the pure cyclodextrin derivative[bis-(6-oxym-carboxybenzenesulfonyl)-?-cyclodextrin Fine(?-CD-M1)]column(column 3),MOFs column 1,and MOFs column 2 are compared in terms of separation of 9 chiral substances(CM,fenoxaprop-ethyl,fluralaner,quizalofop-ethyl,bifenthrin,ranolazine,dropropizine,ornidazole and doxazosin).The results show that column 3 have no effect on the resolution of 9 chiral compounds.There are more chiral binding sites,more complex pore structure,and more the high porosity in the?-CD-MOFs chiral column material.It is gived a greater advantage in chiral recognition than pure cyclodextrin derivative HPLC column materials(have not constructed a metal-organic framework environment).At the same time,there is a big difference between column 1 and column 2 for the resolution of the same chiral compound.The pore structure,pore size,and porosity of the pillar 1 and pillar 2 materials formed by two different synthesis methods are quite different,resulting in different chiral environments.This research has developed a new type of?-cyclodextrin chiral MOFs material.It is established its research ideas and methods for the resolution of chiral compounds on HPLC stationary phases. |
PDF Full Text Request