Evaluation of thermodynamic properties and correlation of L-glutamic acid solubility in some aqueous chloride solutions from 298.15 to 323.15 K

Abstract

This paper investigates the solubility–temperature dependence data for L-glutamic acid (Glu) in water and in some chloride salt (NaCl and KCl) aqueous solutions. Solubility data were determined from 293.15 to 318.15 K under atmospheric pressure by using a thermostatted reactor and the gravimetric method. After the investigation of the impact of inorganic salts on the solvency of Glu, it was found that the salting-out effect decreases in the following order: sodium chloride > potassium chloride. Results demonstrated that the solubility, in unadulterated water and in aqueous chloride solutions, increased with a rising temperature. The experimental data were well correlated by the semi-empirical equation. Using the measured solubilities, the standard molar thermodynamic properties of transfer of Glu (ΔtrG°, ΔtrH°, and ΔtrS°) from pure water to aqueous solutions of the chloride salts were estimated.