Measurement and Correlation of Solubility of Glutathione in Four Binary Solvents from 278.15 to 318.15 K

The solubilities of glutathione in four binary solvent mixtures (water + acetone, water + 1,4-dioxane, water + acetonitrile, and water + tetrahydrofuran) were measured using a dynamic laser monitoring method at temperatures ranging from 278.15 to 318.15 K. The molar fraction solubility of glutathione in the binary solvent increased with increasing water content and temperature. The modified Apelblat, CNIBS/R-K, Van’t Hoff–Jouyban–Acree, Apelblat–Jouyban–Acree, and NRTL were applied to calculate the solubility of glutathione in these mixtures. The relative average deviation and root-mean-square deviation indicated a good correlation between the experimental and model solubility data. In addition, the KAT-LSER model was used to evaluate the solvent effect in the solvent–solvent and solvent–solute interactions. The results showed that the nonspecific dipolarity/polarizability interactions between the solvent and the solute were the main influencing factors, followed by the hydrogen bonding interactions between the solvent and the solute.