| Supercritical fluids have the physical properties of the high diffusion coefficient and low viscosity as gases, and have the similar density and solubilizing power as liquids. Supercritical fluids are used as mobile phase in supercritical fluid chromatography, it was suitable to separate natural and biological products and remove the small amount impurity of high value and thermally labile compounds. The recent progress of supercritical fluid chromatography and the separating process of natural Vitamine E were reviewed. It was proposed to separate and prepare the natural Vitamine E by supercritical fluid chromatography. It was studied combining the basic research of supercritical fluid chromatography and the development of process in this dissertation.It was comprehensively studied that the effect of pressure, temperature and modifier concentration in the mobile phase on the capacity factor, selectivity and resolution of tocopherols. α , γ and δ -tocopherol isomers can be eluted by the supercritical carbon dioxide on the DIKMA ODS column(250mm X 4.6mm I.D. , 5 μ ). In the range of pressure 16 to 22 MPa and temperature 303 to 343K, the capacity factor of tocopherols decreases as pressure increases and increases as temperature increases. The selectivity of tocopherols increases as temperature increases and the pressure has little effect on the selectivity of tocopherols. The eluted order of tocopherols changed with temperature. On the Waters spherisorb silica column(250mm X 3.9mm I.D. , 5 μ ), tocopherols can not be eluted by supercritical carbon dioxide, they can be eluted soon when ethanol and isopropanol were added into the supercritical carbon dioxide as modifier with the improved shape of peaks and separating effect. The range of the studied pressure, temperature and ethanol concentration in the mobile phase was 12 to 20MPa, 303 to 363K and 0 to 6.54%(w%) respectively. It was founded that the capacity factor of tocopherols decreases as the ethanol concentration in the mobile phase increases; and there is a maximum of the resolution of tocopherols to the ethanol concentration curve at definite temperature and pressure. The capacity factor and resolution increase as pressure decreases, the pressure has little effect on the selectivityof tocopherols. There is a maximum of capacity factor of tocopherols to temperature curve in various pressure conditions, with the exception of the pressure 14MPa that the capacity factor of tocopherols increases as temparature increases. The selectivity of Y and 8 -tocopherol increases as temperature increases, however, there is a maximum of the selectivity of a and Y -tocopherol to temperature curve. The resolution of tocopherols increases as temperature increases. The better separatiing conditions of tocopherols on the silica gel column were: temperature 333K, pressure 14MPa and ethanol concentration 4.9%(w%).A simplified model of capacity factor: based on the unified molecular theory was proposed. The experimental data were correlated by the model with the AARD% less than 1% in the supercritical carbon dioxide on the ODS column and less than 13.32% on the silical gel column while modifier was added into the supercritical carbon dioxide.The conecentration of Vitamine E that can be injected on the analytical silical gel column was studied. The maximum of injected concentration of Vitamine E was 600mgmr'. The product was collected in this concentration of Vitamine E, the purity of tocopherols was improved from 49.95 to 82.33% by the technology of cutting, and the yield was 54.2%. Two experiental equtions were employed to correleted to the back of impurity and the front of the Vitamine E. It was calculated the cutting time, output and yied of Vitamine E at several concentration of Vitamine E. The amount of materials to prepare high purity Vitamine E of 100 tons by supercritical fluid chromatography was calculated too, and the possibility was discussed roughly.A mathematical model of supercritical fluid chromatography has established with the assumptions of li...
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