Preparation And Characterization Of Monolithic Silica Column

High performance liquid chromatography (HPLC) is one of the most widely used methods of separation and analysis. The chromatographic column as the heart of high performance liquid chromatography has a rapid development in recent years. Compared with conventional packed columns, monolithic silica column has low pressure, fast analytical speed, gradient elution speed, high resolution and good selectivity. It has been widely applied in the separation of macromolecules acting as a new type of chromatographic stationary phase. In this paper, silica gel is the silica source which has been made by crystal silicon powder. Under alkaline conditions (pH=8-9), it can use polyethylene glycol (PEG) as the porogen and tetramethoxysilane (TMOS) as cross-linking agent. Monolithic silica column with a high purity and bicontinuous network of macropores and mesopore have been prepared by the sol-gel method. The structure and properties of the products were characterized by Scanning Electron Microscope, Infrared Spectroscopy, Solid-State NMR, Elemental Analysis and BET nitrogen desorption.This paper mainly includes the following contents and innovations:(1) All of the type of silicane reagent, ratio of silica gel/silane reagent, silica gel content, PEG molecular weight, PEG addition amount, pH, aging temperature and calcination temperature have an important influence on the synthesis of monolithic silica column. By means of SEM, BET and other analytical methods, the through pore and specific surface area were characterized accurately. With methanol and water being the mobile phase, benzene, toluene, anthracene and naphthalene were separated by HPLC.(2) The stationary phase of reverse phase chromatography was synthesized by bonding a long chain of C18 on the surface of monolithic silica column. By Elemental Analysis, Infrared Spectroscopy, NMR and other analytical methods, the bonded monolithic silica column was also characterized by HPLC.A new monolithic silica column has been prepared viva sol-gel method in alkaline medium which has a fundamental importance to chromatographic separation.