碩士 / 明志科技大學 / 生化工程研究所 / 100 / A novel extraction method, aqueous two-phase extraction systems based on the various imidazolium ionic liquids (ILs) and potassium salts (K2HPO4, K2CO3, and K3PO4) have been used for the extraction of C-phycocyanin (CPC) from cyanobacteria Spirulina platensis. Three kinds of ILs were chosen in this work, including 1-butyl-l-3-methylimidazolium bromide ([C4mim][Br]) 1-hexyl-3-methylimidazolium bromide ([C6mim][Br]), and 3-methy-1-octylimidazolium bromide ([C8mim][Br]). The two-phase forming ability by adding approximately amount of these potassium salts to aqueous ILs solution has been observed very similar. In this study, K2HPO4 was chosen for further study because of its strong phase-forming ability and can result in an approximate pH range for CPC extraction. The influences of pH, volume and concentration of disrupted algae used, temperature, and alkyl chain length of ILs on the extraction efficiency were investigated. The extraction efficiency of C-PC was found to be changed slightly between pH 6 and pH 8.
The experimental results showed that approximately 97% of the CPC could be extracted into the ILs-rich phase at pH 7 and 4oC. The extraction efficiency of CPC was found to increase with increasing the temperature and alkyl chain length of the cation of the ILs. It indicated that the hydrophobic interactions were the main interaction force, although the electrostatic interactions and salting-out effects may also play an important role. The optimal extraction conditions for extraction of CPC were 1% and 0.5 mL of disrupted cells, and temperature of 37oC at pH 7. The order of extraction efficiency for CPC was [C8mim][Br]> [C6mim][Br]> [C4mim][Br]. The partition coefficient of [C8mim][Br] and K2HPO4 system for CPC was as high as 20.46 with a extraction yield of approximately 97.8%.
The extraction kinetic data for CPC were tested by using pseudo first and second order reactions. The results showed that the rate of extraction process followed the second-order rate kinetics. The rate constants and activation energy (Ea) of extraction for all these kinetic models have been calculated. Additionally, the thermodynamic parameters, such as Gibbs free energy (Go), entropy (So), and enthalpy (Ho) have also been evaluated for the extraction of CPC. It has been found that the extraction of CPC was feasible, exothermic process, and spontaneous.
| Identifer | oai:union.ndltd.org:TW/100MIT00723007 |
| Date | January 2013 |
| Creators | Ci-Rong Huang, 黃啟榮 |
| Contributors | Jung-Chin Tasi, Yu-Kaung Chang, 蔡榮進, 張煜光 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 57 |
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