Liquid-liquid equilibrium of novel aqueous two-phase systems and evaluation of salting-out abilities of salts

Abstract

Binodal data are beneficial to the design of aqueous two-phase extraction and the establishment of thermodynamic models. For the 2-propanol + Li2SO4/Na2SO4/(NH4)2SO4/K3PO4 + water systems and 1-propanol + K3PO4/K3C6H5O7/(NH4)3C6H5O7 + water systems, binodal data were determined at 298.15 K. The binodal data were correlated by a theoretical equation on the basis of statistical geometry. The salting-out abilities of salts and the phase-separation abilities of alcohols were evaluated by the effective excluded volume of salt and the binodal curves plotted in molality. A simple Hofmeister series of cations and anions were obtained. The organic salt, K3C6H5O7, shows as high a salting-out ability as K3PO4. © 2010 Versita Warsaw and Springer-Verlag Wien.