Extraction And Separation Of Artemisinin From Artemisia Annua L

Extraction and separation of Artemisinin from wild Artemisia annua L. in Tianjin was studied in this dissertation, a rational extraction technical route based on Artemisinin raw material was established, and the simulation of the extraction process was achieved using the error back-propagation network. The main contents and results of the research included: 1. The measuration method of Artemisinin was verified based on previous studies, and the Ultraviolet Spectrophotometry was selected as a simple accurate method, but the mass concentration of NaOH solution should be within 0.2%± 0.02%, otherwise, the absorbance of Q292 would be reduced, and the accuracy of the content determination was also affected. 2. Artemisinin from Artemisia annua L. was only worth extracting when it's content of Artemisinin was above 2mg/g according to literature. Using the Ultraviolet Spectraphotometry, the content of Artemisinin was determined as 5.0377mg/g after five parallel experiments. Thus the conclusion was confirmed that the content of Artemisinin in Tianjin was comparatively high, and Artemisia annua L. in Tianjin was worth exploiting and using. 3. The constant-temperature stirring extraction was affirmed having the highest extraction mass rate of recovery, compared with the infusing under room temperature and Soxhlet extraction methods, which mass rate of recovery was 46.48% and 68.9%. The effects of temperature, time, stirring speed, grinding drgree of material, quantity of solvent and other factors on the extraction rate of recovery were discussed, and the results were also given that those factors were beneficial to the extraction of Artemisinin within a certain range, and the extraction rate of recovery got a rapid increase within this range, then the increasing tendency slowed down and gradually presented the downtrend beyond this range. By the optimizing experiment, the appropriate technical conditions were established as extraction time at 180min, temperature at 50℃, stirring rate at 800 r/min, material grinding degree at 60 meshes,solvent quantity at 60mL/g.Under those conditions, the average extraction recovery rate of Artemisinin was 90%, but in literature was only 83%.These experiment results could be a guide for improving the extraction techniques. 4. The better result of refining and dewaxing was achieved by using the ethanol solution with mass concentration of 70%. By the optimizing experiment, the appropriate technical conditions were established as extraction time at 3 hours, mass proportion of additive benzene at 0.2, volume proportion of extraction solvent at 1.0. Under these conditions, the extraction rate was as high as 83.52%. The coarse crystal of Artemisinin was obtained by the crystallization and recrystallization. 5. A technical route to extract Artemisinin from Artemisia annua L. was established by the study of extraction (constant-temperature stirring), separation (extracting with solvent), and refine(crystallization) technical processes, which overall Artemisinin recovery rate was 81.5% (Artemisinin extraction quantity/raw material quantity amount to 0.41%). Contrast with the routes using gasoline (Artemisinin extraction quantity/raw material quantity amount to 0.3%) or ethanol (Artemisinin extraction quantity/raw material quantity amount to 0.24%) as solvent, this technics got a prodigious improvement. 6. Considering the complexity of the extraction production and process, a simulation of the extraction process was achieved using the error back-propagation network, and the simulation results were in accord with the experiment dates. The effects of those factors on the extraction process was discussed, and the results indicated that the temperature and the time of the extraction had a noticeable effect on the recovery rate of Artemisinin, thus the design and the operation of the experiment would be better supervised.