Studies On Extraction Of Artemisinin By Tetrafluoroethane

Extraction and separation of Artemisinin from wild Artemisia annua L.in Zunyi was studied in this dissertation, a rational extraction technical route based on Artemisinin raw material was established. 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 temperature of the ramification should be within 50℃±1℃and 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 Spectraphotometey, the content of Artemisinin was determined as 8.957mg/g after five parallel experiments. Thus the conclusion was confirmed that the content of Artemisinin in Zunyi was comparatively high, and Artemisia annua L. in Zunyi was Worth exploiting and using.3. In order to ascertain the best technical route to extract Artemisinin from Artemsia annua L.by Tetrafluoroethane, we discuss the monofactor effects of time,temperature,stirring speed,grinding degree of material and the quantity of Tetrafluoroethane on the extraction rate of recovery,and the results were also given that those factors were beneficial to the extraction within a certain range. By the optimizing experiment,the appropriate technical condition were established as extraction time at 60min,temperature at 50,stirring rate at 400r/min,material grinding degree at [80,100]meshes,solvent quantity at 120mL/g.Under those conditions,an average extraction recovery rate we can concluded was 90.37%,but in literature the average was only 83% by organic solvent.Those experature results could be a guide for industrialization later. 4. The better result of refining and dewaxing was achieved by using the petroleun ether with boiling point of 30℃-60℃.The crystal of Artemisinin was obtained by the crystallization and recrystallization.5. Through the technical route to extract Artemisinin from Artemsia annua L. which was established by the way of extraction(constant-temperature atirring with Tetrafluoroethane),separation(extracting of petroleun ether), refining (recrystallization), a new technical route with the total recovery rate we can got was 77.7%.