Abstract
The protonation equilibrium constants of 2,3-dihydroxybenzic acid (DA) in aqueous solutions was achieved by the HYPERQUAD 2008 software estimation from the pH-potentiometric and spectrophotometeric titration data, which present a multiplicity of statistics arrangements. Aa assessment of the influence of the organic solvent dimethylsulfoxide (DMSO) on the association and protonation processes was also testified and elucidated. The solution equilibria of 2,3-dihydroxybenzic acid was studied at 298.15 K in a water + DMSO liquid mixtures [100 womso = 20%, 40%, 60%, and 80%] with an ionic strength of 0.16 mol.dm(-3). The effect of DMSO on the protonation processes was measured and explained. The spectrophotometry evaluation was also done for 2,3-dihydroxybenzic acid bioligand at different pH stages in aqueous solutions and its absorbance ratio was also detected. (C) 2019 Elsevier B.V. All rights reserved.