MASS TRANSFER CHARACTERIZATION IN FORWARD AND BACK EXTRACTIONS OF AN AMINO ACID BY REVERSE MICELLES ACROSS A FLAT LIQUID-LIQUID INTERFACE

摘要

The mass transfer characterization in reversed micellar extraction of the amino acid phenylalanine (Phe) is presented. The mass transfer rates in forward extraction of Phe from aqueous KC1 solutions (pH 1.4～2.3) to AOT/isooctane reversed micellar solutions and in back extraction from the organic phase to KHCO_3/KOH buffer solutions (pH 9.0～11.0) were investigated using a stirred cell with a flat liquid-liquid interface. Both the forward and the back extraction rates are controlled by the interfacial rate processes, i.e., the solubilization and the release processes. The effects of pH, initial AOT and Phe concentrations, ionic strength and alcohol addition on their rates are demonstrated. The back extraction rates are fairly slow compared to the forward extraction rates, and are extremely accelerated by the addition of 2-methyl-2-propanol as well as the extraction of protein lysozyme.