Solubility and solvation thermodynamics of l-tryptophan in aqueous methanol solvent mixtures

Abstract

This article presents mole fraction solubilities of l-tryptophan in binary aqueous methanol solvent systems and applied them to estimate thermodynamical parameters like transfer Gibbs free energetics and entropies of solutions. The estimated thermodynamic energies were linked with interaction parameters like dipole–dipole interactions, enthalpy due to transfer of l-tryptophan from water to binary water–methanol solvent mixtures. The transfer Gibbs free energetics for chemical interactions and entropies for solvent–solvent interaction were calculated by mathematical relations. The chemical transfer energetics was applied to explain the probable stability of l-tryptophan in the mixed solvents. Many associated thermophysical parameters were also calculated at standard temperature (298.15 K).