Preparation And Evaluation Of Multi-groups Bonded Hydrophilic Chromatographic Materials

Hydrophilic interaction chromatography (HILIC) can be used as a supplement to reversed phase chromatography (RPLC) and has been proved a powerful technique in separate and analysis of polar and hydrophilic compounds. It has been widely used in metabolomics, proteomics, glycomics, sugar proteomics and so on. As the core of HILIC, HILIC stationary phases’development directly affects the application of the chromatographic techniques. Although some HILIC stationary phases can be bought in the market, the development of novel HILIC stationary phases remains a hot research topic. Based on these considerations, two HILIC stationary phases were prepared in this paper. Moreover, their separation performance and mechanism were studied. Meanwhile, a silica adsorbent which can adsorb aromatic acids specifically was synthesized.A linear tetrapeptide stationary phase was synthesized by grafting of linear tetrapeptide to the silica surface. Through investigating the effect of column temperature, the water content, pH and salt concentration of mobile phase on the retention time of polar compounds, it was found that the new material could be used as a HILIC stationary phase. The stationary phase could separate nucleosides, sulfonamides and substituted benzoic acids compounds quickly. Meanwhile, the stationary phase could be used to separate isomers, such as nitro, amino or hydroxy-substituted benzoic acid compound. Compared with the cyclicpeptide stationary phase, the linear tetrapeptide stationary phase showed stronger hydrophilia and the cyclicpeptide stationary phase showed unique size selectivity.Polydopamine modified silica stationary phase was synthesized by the polymerization of dopamine in alkaline condition, and its successful synthesis was confirmed by elemental analysis and thermogravimetric analysis. The volume of the aqueous enrich layer of the stationary phase was measured by the method raised by Bicker. The effects of the water content, pH and salt concentration of mobile phase on the retention of test compounds were investigated to evaluate the HILIC retention mechanism of new stationary phase. By adding amine modifier to the mobile phase and comparing with a bare silica column, it is found that the silanol groups on the surface of silica matrix in the new stationary phase were sheltered successfully. Compared with the HILIC column produced by MN company, the new stationary phase showed more hydrophilic and better separation of safflower injection.A silica adsorbent contained with tertiary amine, secondary amide and primary amine was synthesized. The sorbents can be used to adsorb aromatic acids specifically with high adsorption speed, large adsorption capacity and easy desorption with high recovery.