Study of amino acids electrotransport through a organic charged membrane

• Main Authors: Shu-Peng Dai, 戴叔朋
• Other Authors: Po-Da Hong
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/16093020530850830896

碩士 === 國立臺灣科技大學 === 高分子工程系 === 91 === Recently, the separation of amino acids is examined with ion-exchange membrane. But, the value of the diffusion flux which has been measurd under zero current density and under a concentration gradient of amino acid inside the membrane is much lower than the migration flux which has been measured under nonzero current condition. Membrane separation technigues of electrotransport have been proposed for the extraction and separation of amino acid. In this study, the diffusion and electrodiffusion of amino acid, alaine and lysine, from their mixed solution were examined with a cation-exchange membrane, Nafion 117, at different pH varying from 2 to 9, under various current densities in the range of 0 to 5.71 . The experimental results of experiment indicate that the pH of the solution has a strong influence on the current efficiency of the electrotransport of amino acid. At high pH, local proton depletion in the aquous layer in contact with the membrane will induce a lowering of ionization of amino acid, and the best value of the acid pH for separation of amino acids is around 8. The amino acids are almost completely separated from each other under this condition. Only lysine is transported across the cation-exchange membrane, and Alaine is not transported at all.