Study On The Synthesis Of Hydrophilic And Hydrophobic Separation Materials Via SI-ATRP And Their Properties

In this paper, two kinds of HILIC and RPLC chromatographic stationary phase for HPLC were synthesized by atom transfer radical polymerization (ATRP) method based on silica as matrix. The chromatographic properties and retention mechanism of those stationary phases were investigation in detail. We used the stationary phases to separate polar compounds and small molecules, and achieved good results. The paper mainly includes the following several parts:1. A novel PDMAEMA stationary phase for hydrophilic interaction chromatography (HILIC) was prepared via surface-initiated atom transfer radical polymerization (SI-ATRP). The chain length and the grafting density controlled of three PDMAEMA chromatographic columns were obtained by changing the concentration of the monomer in the polymerization process. In HILIC mode, seven kinds of nucleoside compounds could be separated on the packing, and retention time of the solute was gradually increasing with the increased amount of monomer grafting on the stationary phase. We investigated water content, salt concentration in mobile phase and mobile phase pH influences on retention time of nucleoside compounds in detail, and calculated the hydrophilic mechanism. The experimental results show that polarity molecules had good separation performance on the chromatographic packing, and accorded with distribution mechanism in HILIC. Finally, we used the chromatographic column to separation and determination of the nucleoside compounds in Ningxinbao Capsule. The result is satisfactory.2. Imidazoline monomer was synthesized by microwave assisted. Using5.0μm macroporous silicas as a matrix, a new type of hydrophilic chromatographic stationary of Sil-Im was prepared by SI-ATRP. We tested the separation performance of organic acid and nucleoside compounds in the Sil-Im. Water content, salt concentration, column temperature and salt effecting on retention time of organic acid were investigated, and the hydrophilic mechanism was studied. The results showed that the polarity and hydrophilic molecules for chromatographic packing has good separation performance, and the retention mechanism involved the mixed interactions of partitioning mechanism and adsorption mechanism. The stationary phase was also used to determination the content of vanillic acid in cortex lycii radicis.3. Using5.0μm macroporous silica as a matrix, a novel Sil-LMA stationary phase for reversed phase liquid chromatography (RPLC) was prepared via SI-ATRP. We tested the separation performance of amine and hydroxybenzene compounds on the Sil-LMA. The temperature, methanol content effecting on retention time of amines were investigated. The results showed that the chromatographic packing has good separation performance, and in line with the inverse mechanism. The amines retention time decreased with the column temperature increased. Calculating the enthalpy (△H) were negative, which explained that the solute form the mobile phase to stationary phase was exothermic process.