Solubility and thermodynamics of L-hydroxyproline in water and (methanol, ethanol, n-propanol) binary solvent mixtures

Solubility of L-hydroxyproline in water and binary solvent mixtures with methanol, ethanol or n-propanol was systematically determined in a temperature range of 293.15 K–318.15 K under 0.1 MPa. The solubility increased with temperature and increased with increasing composition of water in the binary solvent mixtures. Thermodynamic properties of L-hydroxyproline, such as melting enthalpy, fusion enthalpy and decomposition temperature were determined. Modified Apelblat equation, Jouyban-Acree model, Wilson model, and NRTL model were used to analyze the solubility data and relations with thermodynamic properties of L-hydroxyproline at various solvents.