Study On The Application Of Column Chromatography To High-purity Separation Of Natural Products And Relative Theory

It is very important to apply the traditional separation technologies of chemical engineering into the field of separation and purification of natural products, especially the natural products in agricultural byproducts. It can add value to agricultural products, promote the modernization of agriculture and help to maintain the sustainable development. Our country is abundant in natural products, and the technology of natural product extraction is well known, however, the technology of high-purity separation is lack. For all the available natural product purification technologies, liquid chromatography is the most widely used. But, the research on the application of liquid chromatogrtaphy to the productive scale purification of natural products is rarely reported domestically. There are a lot of problems in this area, such as the antinomy between flow resistance and separation efficiency, lack of simulation methods of the separation processes and so on. In this work, the chromatographic matrix(the separation reagent) modification and the technics and related theories for scaling up of liquid chromatography are studied in the background of purification of general flavonoids from bamboo leaves and the purification of solanesol, respectively. Polyamide column chromatography and silica gel column chromatography are used in the purification of these two kinds of natural products, respectively. The productive-scale purifications for these two kinds of natural products are realized.For the purification of general flavonoids from bamboo leaves, a new kind of composite polyamide matrix is produced, which has a small resistance and a good adsorption capability. And it was used in the liquid chromatography purification of general flavoniuds from bamboo leaves at atmosphere pressure. The technological conditions are optimized and the purification is carried out while the mobile phase flux is scaled up. The result shows that the maximum flux of the composite matrix column is 12 times of that of a pure polyamide colmn. This work is a try to solve theantinomy between flow resistance and separation effeciecy and to realize the scale-up of the flux of the mobile phase at atmosphere pressure.For the purification of solanesol, the silica gel column chromatography and crystallization are used. Firstly, the solubilities of solanesol in acetonitrile, ethyl alcohol and n-hexane are determined using composite method. Then, the qualitative and the quantitative analysis methods of solanesol are established by TLC method and HPLC method, respectively. The technics of purification of solanesol using silica gel column chromatography is then studied. In order to describe the kinetics of liquid chromatography, the numerical solution and the programming of the multi-component nonlinear liquid chromatography rate model is studied in detail. The numerical method of the model is optimized and the rapidity of convergence of the calculation is enhanced. After the adsorption isotherm of solanesol on the surface of silica gel is determined, the liquid chromatography rate model for solanesol purification on silica gel column is established and used to simulate and predict the separation process. The result shows that the established model describes the separation process well. The effects of operation parameters of the chromatography separation are studied using the model simulation. Finally, after scaled up in the lab, the productive scale experiment of the silica gel column chromatography purification of solanesol was carried out, and the product of 97% purity was gained.