Preparation And Evaluation Of Multifunctional Monomers Bonded Mixed-mode Stationary Phase For HPLC

Objective:?1?Preparation of a mixed-mode liquid chromatography functionalized imidazolium based ionic liquid embedded C18 and an aryl sulfonate group?Sil-ODM-VSS?.?2?Preparation of a poly?ethyleneimine?embedded phenyl stationary phase for mixed-mode liquid chromatography.?3?Preparation of an ionic liquid functionalized?-cyclodextrin and C18 as mixed-mode stationary phase for high performance liquid chromatography.Furthermore,study on the chromatographic performance and applications of these mixed-mode stationary phases.Methods:?1?The“thiol-ene”click chemistry was employed to synthesize the Sil-ODM-VSS material using 3-n-octadecyl-1-vinylimidazolium bromide and 4-vinylbenzenesulfonic acid sodium as functional monomers.The intermediate was identified by nuclear magnetic resonance?NMR?analysis.The Fourier transform infrared spectrometer?FT-IR?,element analysis?EA?and thermogravimetric analysis?TGA?were chosen to characterize the bare and modified silica beads.The impacts of chromatographic conditions and column packing procedure on chromatographic peak shape and column efficiency were studied by alkylbenzenes as probe sample.The hydrophobic alkylbenzenes,terphenyls,polar nucleosides and nucleoside bases,flavonoids,ionizable benzoic acids,phenols and anilines were used to evaluate the chromatographic performance and separation interactions of the mixed-mode stationary phase Furthermore,the chromatographic performance of Sil-ODM-VSS column was compared with that of traditional commercial ODS column.In order to demonstrate the reversed-phase,hydrophilic interaction and ion-exchange modes of Sil-ODM-VSS column,the relationship between retention time of analytes and mobile phase composition and pH value were studied.The separation of Qinghuozhimai and vitamin B₂ tablets were chosen as the application,respectively.?2?The epoxide ring opening reaction was employed to synthesize the Sil-PEI-GPE material using hyperbranched poly?ethyleneimine?and glycidyl phenyl ether as functional monomers.The surface chemical properties of activated silica,Sil-GPTS,Sil-PEI and Sil-PEI-GPE materials were characterized by EA,FT-IR and TGA.The reversed-phase,hydrophilic interaction and ion-exchange chromatography were studied by PAHs,terphenyls,alkylbenzenes,nucleoside and nucleoside bases,flavonoids,benzoic acids and phenols.Moreover,the chromatographic performance of Sil-PEI-GPE column was compared with that of traditional commercial ODS column.Due to the high content of amino and phenyl on the stationary phase materials,aromatic amines were selected to evaluate the benzene ring attraction and amino repulsive interactions of the Sil-PEI-GPE column.The application is to establish a method for the rapid separation and determination of phenylenediamines in hair dye on the Sil-PEI-GPE column.?3?The“thiol-ene”click chemistry was employed to synthesize the Sil-ODM-CDM material using 3-n-octadecyl-1-vinylimidazolium bromide and6-?1-allylimidazolium?-cyclodextrin tosylate as functional monomers.The ionic liquids and intermediate were identified by NMR.The FT-IR,EA and TGA were chosen to characterize the activated silica beads,Sil-MPS and Sil-ODM-CDM materials.The HPLC performance of the as-prepared column was evaluated by hydrophobic,hydrophilic and ionic compounds.The retention mechanisms of reversed-phase,hydrophilic interaction and ion-exchange modes on the developed stationary phase were researched by changing the proportion of organic phase and pH value of mobile phase.The enantiomers of1-phenylpropanol,warfarin,styrene oxide,ibuprofen and ketoprofen were used to evaluate the enantioselectivity of the column.Results:?1?The obvious chemical shift belonged to the hydrogen of methylene was observed in NMR spectrum and the data was in accordance with the literature.Compared with the bare silica,there were more signal peaks in FT-IR spectra,after modification of silica by silane reagent and functional monomers.The results of EA and TGA showed that the organic chemicals on the surface of modified silica increased.And there was no significant difference in the chromatograms of probe sample before and after changing the injection volumn,sample concentration and column temperature.After optimizing the column packing conditions,the peak shape of alkylbenzene compounds was markedly improved.The hydrophobic,hydrophilic and ionic compounds were successfully separated under the corresponding reverse-phase,hydrophilic interaction and ion-exchange modes,respectively.Fast elution of Vitamin B₂was obtained under the condition of acetonitrile and acetic acid as mobile phase?2?The characteristic peaks of methyl,methylene and benzene ring were observed in the FT-IR spectrum of Sil-PEI-GPE material.According to the data of EA,the bonding density of nitrogen element on the surface of silica was 4.71?mol m^-2.And the weight loss rate of Sil-PEI-GPE material was about 50%at high temperature.The o-terphenyl and triphenylene with highly similar structure were successfully separated on the prepared column.Based on the benzene ring attraction and amino repulsive interactions,baseline separation of six aniline compounds was obtained.The linearity of p-phenylenediamine and o-phenylenediamine on the prepared column were y=56617x-6283 and y=28056x-1121.3,and both correlation coefficients?R²?were over 0.999.The content of p-phenylenediamine and o-phenylenediamine in a commercial hair dye were 0.63 mg g^-1 and 2.10 mg g^-1,respectively.?3?The NMR spectra of ODM ionic liquid,CD-Ts intermediate and CDM ionic liquid showed there were chemical shifts of hydrogens of methylene,benzene ring and imidazole ring,respectively.Compared with the bare silica,there were more signal peaks in FT-IR spectra,after modification of silica by silane reagent and functional monomers.The results of EA and TGA showed that the organic chemicals on the surface of modified silica increased.The hydrophobic PAHs,terphenyl position isomers,alkylbenzenes,polar nucleosides and nucleoside bases,ionizable benzoic acids,phenols and anilines were successfully separated under the reverse-phase,hydrophilic interaction and ion-exchange modes,respectively.The enantiomers of 1-phenyl-1-propanol,warfarin and styrene oxide were separated rapidly under reverse-phase mode respectively.And fast enantioseparation of ibuprofen and ketoprofen were obtained within 4 min under polar organic mode.Conclusion:?1?A reversed-phase,hydrophilic interaction and ion-exchange mixed-mode stationary phase material has been successfully prepared.The issue of the frontal chromatographic peak can be effectively settled by increase the concentration of primary stationary phase material in column packing.And the as-prepared column has the potential to be used for separation and analysis of complex samples.?2?A poly?ethyleneimine?embedded phenyl stationary phase for mixed-mode liquid chromatography was successfully prepared.The mixed-mode material with polar embedded hydrophobic group showed specific selectivity for position isomers.And the Sil-PEI-GPE column has potential application for the rapid separation and analysis of aniline compounds in complex samples.?3?An ionic liquid functionalized?-cyclodextrin and C18 as mixed-mode stationary phase for high performance liquid chromatography has been successfully prepared.Multiple separation modes of various samples can be realized by adjusting the chromatographic condition of the Sil-ODM-CDM stationary phase.The interactions from the?-cyclodextrin bonded stationary phase enable the chiral separation on the Sil-ODM-CDM stationary phase.