| Summary: | 碩士 === 長庚大學 === 化工與材料工程研究所 === 97 === In this research, we used the supercritical carbon dioxide dynamic extraction of quercetin of onion, and the extractions were analyzed by high-performance liquid chromatography and supercritical fluid chromatography. Our purpose is to separate the highly value-added quercetin from the onion with a absolutely pure extraction facility. In order to find the best operation condition, various factors such as extraction pressure, extraction temperature, different modifiers, rate of flow, extraction time, and the dynamic-static extraction mode were discussed. Furthermore, the comparisons between the productions of traditional extraction and supercritical fluid extraction have been made; the HPLC and SFC analysis were applied respectively.
The results show the intention substance is high extraction efficiency in 5000 psi, 80℃, and 6 hours. Ethanol is used as modifier and flow rate is 0.2 ml/ min.
A reversed HPLC method was applied, and the best proportion for mobile phase was acetonitrile (solution A) and 0.5% phosphoric acid (solution B). The program began with a gradient elution from 10% to 35% A, and from 90% to 65% B for 10min, followed by a gradient from 35% to 10% A, and from 65% to 90% B for the next 6 min. The flow rate was fixed at 1 ml/ min. The maximum absorbability wavelength is at 365 nm wavelength.
For SFC, the quercetin standard could be analysis at 2000 psi, 40℃, flow rate is 1.7 ml/ min, supercritical CO2 with 30% (v/v) ethanol as modifier. If quercetin concentration is lower than 200 ppm, the signal was unable to be judged due to the high noise.
Keywords : Supercritical fluid extraction, Carbon dioxide, Onion, Quercetin, High-performance liquid chromatography,
Supercritical fluid chromatography
|
|---|
