以非分散式支撐及乳化型液膜回收與分離胺基酸

Separation of Amino Acids Using Non-dispersive Supported and Emulsion Liquid Membranes

陳嘉南(Chia-Nan Chen)

指導教授 ： 莊瑞鑫

元智大學/工程學院/化學工程與材料科學學系/碩士(2005年)

摘要

本實驗主要利用胺基酸為兩性物質具有等電點的特性，不同胺基酸其離子狀態隨pH值的差異，在萃取的過程中，必須選擇適當之萃取劑，並控制適當之pH值來分離不同的胺基酸。本實驗以酸性萃取劑二(2-乙基己基)磷酸(D2EHPA)為載體，探討應用中空纖維薄膜接觸器分離及濃縮雙成分胺基酸(天冬胺酸與苯丙胺酸)水溶液的可行性。
在溶劑萃取的部分實驗結果得知(1)苯丙胺酸萃取率隨著pH值增加而上升(2)天冬胺酸萃取率隨著pH值增加而減少(3)反萃取pH值越低越利於苯丙胺酸的析出(4)萃取劑濃度越高越利於兩種胺基酸的分離
在中空纖維薄膜接觸器萃取部分，實驗若在(1)進料相pH值越高分離效果越好(2)反萃取相酸濃度越高分離效果越好(3)進料相、反萃取相流速越快質傳效果越佳，有機相的流速則無影響(4)苯丙胺酸在進料相中所佔的比例越少則苯丙胺酸的選擇率會較高。

關鍵字

苯丙胺酸 ； 天冬胺酸 ； 水溶液 ； 可行性 ； 胺基酸 ； 接觸器 ； 型液膜 ； 胺基酸

並列摘要

The recovery and separation of amino acids from aqueous solutions by using a hollow fiber membrane module have been studied in this paper. Due to the zwitterionic character of amino acids, they had specific isoelectric points (pI). Amino acids could exist as the cationic or anionic form by adjusting the pH value less and greater than their isoelectric points in aqueous solutions. Therefore, a cation-exchange carrier, D2EHPA, may be applied to extract anionic forms of amino acids and to separate two amino acids.
About the selectivity of binary amino acids, it was found that the larger the pH value, the larger the selectivity (1 < pH < 7). It was also found that the larger the concentration of D2EHPA in the organic phase, the larger the recovery.
The hollow fiber experiments were performed by changing the pH value, the D2EHPA concentration, the acidity of strip phase, the concentration ratio of L-phenylalanine and L-aspartic acid in the feed phase, and the flow rate of all phase. It was shown that an increase of D2EHPA concentration in the organic phase and the concentration of the acid in the strip phase would enhance the selectivity. The increase of pH value in the feed phase and the ratio of [Asp]aq/[Phe]aq in the feed phase would enhance separation factor. The selectivity was in the range 1.3 ~ 18.5 .

並列關鍵字

Phenylalanine ； Aspartic acid ； Amino acid