In the field of inorganic separations, the incentive to explore the use of non-aqueous or mixed solvents has been the enhanced selectivity, discovered quite early in such media for Zeolites[1] and ion exchange resins. [2] The partial substitution of an aqueous solution by organic solvent produces a number of changes in an exchange system, such as, change in the solution structure due to the interaction between water and the organic solvent, change in the hydration and salvation of the electrolyte, change in the solvent composition in the resin phase, change in the activity coefficients of the electrolyte in the solution phase as well as in the resin phase, change in the complexation of the metal ion and change in the extent of invasion by an electrolyte. All these changes are mutually dependent and affect the distribution of the metal ion. From the investigations of ion exchange in mixed solvents, it is apparent that the adsorption equilibrium depends markedly on the properties of the organic solvent and reactions with the resin and electrolytes which determine the equilibrium.