Studies On The Crystallization Purification Technology Of Puerarin Induced By Electromagnetic Field

The thesis, which takes puerarin as an object of study, studied the influence of magnetic field, solvents et al. on the specific property of the puerarin crystal, Probed into the effect of magnetic field, solvents et al. factors on the crystallization of puerarin by means of modern instruments, including HPLC, SEM, TGA, DSC , X-ray powder diffraction and infrared spectrum. And found a new method, with which could obtain fine puerarin crystals.The main conclusions of this research are as follows:1. At the room temperature, the crystallization rate of puerarin was increased because of the effect of magnetic field, the intense of which was 0.24T, and uniform grain in order could be obtained in the same solvent.2. The purity of puerarin crystals obtained from the crystallization purification to the extract of which the puerarin content was 92.15% with different solvents induced by magnetic field would be improved to some extent compared with no effect of magnetic field. In the solvent of water in the ratio of one to ten, the purity of crystal could rise to 94.89%; In the solvent of acetic acid and ethanol in the ratio of one to one, the purity of crystal could rise to 97.36 %; in the solvent of isopropanol, the fine puerarin crystal could be obtained, the purity of which was up to 99.52%.3. The recovery rate of puerarin was influenced remarkably by the effect of electromagnetic field in the solvent of isopropanol, the recovery rate of which was three times that the rate acquired in no effect of electromagnetic field.4. The change of melting point of puerarin crystals with analysis by DSC and TGA, and the change of diffracted intensity by X-ray powder diffraction confirmed the effect of electromagnetic field to the crystallization purification of puerarin.5. The infrared spectrum of the puerarin sample induced by electromagnetic field kept the same with the standard infrared spectrum of puerarin.The author discussed the function mechanism of the change of the form ofpuerarin crystals and effect of electromagnetic field:1. Because puerarin was polar glucoside, the difference of solvent resulted in the change of the incorporation rates of the growth units on the positive and negative faces, thus caused the change of the form of crystals.2. The crystallization of puerarin accelerated owing to effect of electromagnetic field on the hydrogen bonds of solution, and the bulk density of crystal changed on account of the function of electromagnetic field " magnetic force of orientation ", at the same time, the arrangement of crystal was affected, thus the purity of crystal improved and arrange closer.