Preparation And Chromatographic Evaluation Of Novel Imidazole Hydrophilic Interaction Chromatography Stationary Phases

As a new chromatographic separation method,hydrophilic interaction liquid chromatography(HILIC)overcomes the deficiencies of normal phase chromatography(NPLC)and reversed phase chromatography(RPLC)in the separation of polar compounds.It provides an alternative for the separation and analysis of polar compounds and hydrophilic compounds.The stationary phase material is the core of this chromatographic technology and it is of significance of its performance in the selectivity and resolution of chromatographic columns.The functional modification on the spherical silica surface to obtain a separation material with different functional groups is one of the main routes for the preparation of HILIC stationary phases.Based on the above research background,three types of novel imidazole HILIC stationary phases had been successfully prepared,and their chromatographic performance and separation mechanism had been investigated.The main research content of this work is as follows:N-(3-aminopropyl)imidazole was bonded onto 3-chloropropyl silica gel to obtain a novel aminoimidazole HILIC phase(Silpr Apr Im Cl),and then two other types of stationary phases with different coordination anion(Silpr Apr Im BF4 and Silpr Apr Im Tf2N)had been successfully prepared by ion exchange.The chromatographic separation performance of the above stationary phases was evaluated in HILIC mode.The results showed that Silpr Apr Im Cl could recognize 26 polar compounds including sugar compounds,nucleosides,and bases except one uronic acid.And these stationary phases displayed a typical HILIC retention characteristic.The changes in column temperature and the different anions(Cl-,BF4-and Tf2N-)had different effects on the retention of analytes.Additionally,tests of actual samples of fructooligosaccharides showed that the obtained material could provide better separation than the commercial amino columns,indicating that it has a good potential for the application in oligosaccharide analysis.N,N-Dimethylaminopropyl imidazole,synthesized by two ways,was bonded onto 3-chloropropyl silica gel to obtain an N,N-dimethyl imidazole ionic liquid HILIC stationary phase(Silpr DMApr Im Cl).And then the chromatographic separationperformance of the stationary phase was evaluated in HILIC mode.The results showed that Silpr DMApr Im Cl could separate 24 polar compounds including saccharides,nucleosides,and bases excluding thymidine and uracil.And this material also exhibited a typical HILIC retention characteristic.Comparing with Silpr Apr Im Cl,Silpr DMApr Im Cl had a better separation capability and stability.The 1,3-propanesultone was bonded to Silpr DMApr Im Cl to obtain a novel imidazole chimeric sulfobetaine zwitterionic HILIC stationary phase(Silpr ZIC).The chromatographic separation performance and the retention mechanism of this material were investigated in HILIC mode.The results showed that the obtained stationary phase could resolve some polar compounds such as sugar compounds,nucleosides,bases,water-soluble vitamins,salicylic acid and its analogous,and display a typical HILIC retention characteristic.