Solubility of glycine in binary system of ethanol plus water solvent mixtures: Experimental data and thermodynamic modeling

The solubility of glycine in different compositions of ethanol-water binary solvent mixtures was measured over the temperature range of (278.15-328.15) K at intervals of 5.00 K by employing an analytical stirred-flask method. The solubility data were fitted using the modified Apelblat equation and the combined nearly ideal binary solvent/Redlich-Kister (CNIBS/R-K) equation, respectively. The modified Apelblat equation was found to regress the solubility data much better than the other two equations. The Van't Hoff equation was used to calculate the apparent molar enthalpy and the apparent molar entropy of solution in the binary mixture solvent system, the dissolving process was endothermic and entropy-driving. The experiment results and correlation models could be used as essential data in the purification of glycine. (C) 2013 Elsevier B.V. All rights reserved.