Separation and Purification of Polyunsaturated Fatty Acids by SolventExtraction and Liquid Membrane Methods Using Silver Salt.

点击翻译按钮获取中文摘要

Extraction equilibria in the extraction of ethyl esters of PUFA (PUFA-Et) such as EPA-Et and DHA-Et with silver nitrate solutions were investigated. The results suggest that PUFA-Et is extracted as the complex (PUFA-Et・nAg) ^<n+> in the aqueous phase (n : number of C=C in PUFA). The solvent effect on the distribution ratio was interpreted by the UNIFAC equation. Addition of alcohol to the aqueous phase incraesed the distribution ratio remarkably.Experiments on the extraction of EPA-Et and DHA-Et contained in bonito oil ethyl ester (bonito oil-Et) with aqueous silver nitrate solutions were performed using a countercurrent vibromixer with a feed inlet in the middle of the column. The results were interpreted by the model calculation.PUFA-Ets in n-dodecane were successfully transported to m-xylene phase against their concentration gradidnts through supported liquid membranes containing silver nitrate as a carrier.A circulating liquid membrane was proposed where a silver nitrate solution was circulated between a feed phase and the receiving phase vessels. PUFA-Ets were transported against their concentration gradients from the feed vessel to the receiving vessel which was kept at higher temperature than the feed vessel. These are new types of uphill transport utiulizing the solvent ] and the temperature effects on the distribution ratios.