Solubility analysis of homologous series of amino acids and solvation energetics in aqueous potassium sulfate solution

Heliyon. 2019 Aug 23;5(8):e02304. doi: 10.1016/j.heliyon.2019.e02304. eCollection 2019 Aug.

Abstract

In this study we estimated the solubilities of glycine, D,L-alanine, D,L-nor-valine and D,L-serine in aqueous mixtures of potassium sulfate (K2SO4) at 298.15 K using analytical 'gravimetric method'. The experimental solubilities of homologous series of amino acids in aqueous K2SO4 mixture were discussed in terms of relative solubility, salting-in and salting-out effect by evaluating the influential constants. The effect of physicochemical and chemical factors on solubility were discussed briefly and correlated with the thermodynamics. Initially, the study of solvation energetics such as transfer Gibbs energies were evaluated based on the calculations from solubility data and relative stability of the experimental molecules was discussed under the experimental condition.

Keywords: Electrolyte solution; Physical chemistry; Salting-in effect; Salting-out effect; Theoretical chemistry; Transfer gibbs free energies.