Capability of PHSC equation of state for thermodynamic modeling of aqueous amino acid and peptide solutions

The Perturbed Hard Sphere Chain (PHSC) equation of state (EoS) has been utilized for thermodynamic modeling of aqueous amino acid and peptide solutions. For this purpose, the parameters of amino acids and peptides have been adjusted to activity coefficient, liquid density and solubility of amino acids and peptides in water. Furthermore, water activity, osmotic coefficient and vapor pressure of aqueous amino acid solution have been predicted. Finally the solubility of amino acid mixtures in water has been calculated using additional adjustable parameters. The results of PHSC EoS were in good agreement with experimental data. Average deviations in estimation of activity coefficients, liquid densities, water activity and osmotic coefficient are 1.44%, 0.38%, 0.067% and 2.6%, respectively. In addition the solubility of mixed aqueous amino acids has been calculated to show the ability of mentioned model.