CORRELATION OF AMINO-ACID SOLUBILITIES IN AQUEOUS ALIPHATIC ALCOHOL-SOLUTIONS

The successful description of separation process performance rests on the ability to describe the relevant thermodynamic and rate parameters. An investigation into the correlation of the solubility behavior of amino in mixed alcohol-water solvents at 25-degrees-C is reported here. The measured solubilities of glycine, L-alanine, L-isoleucine, L-phenylalanine, and L-asparagine monohydrate in aqueous solutions of methanol, ethanol, 1-propanol, and 2-propanol were correlated with the use of an excess solubility approach and the Wilson activity coefficient formulation. Although the relative solubilities of these solutes changed as much as 3 orders of magnitude from water to pure alcohol, all solubility data were correlated with an average error of 15%. It was also noted that the excess solubility behavior of hydrocarbon gases in alcohol-water solvents was very similar to that of the amino acid solutes.