ACTIVITY MEASUREMENTS IN AQUEOUS MIXED ELECTROLYTE SOLUTIONS OF NACL IN NACL - MgCl2 – VALINE- H2O.
Keywords:
Electrolytes, Amino Acids, Activity Coefficients, Osmotic CoefficientsAbstract
The perturbed-chain statistical association theory (PC-SAFT) is applied to simultaneously describe various
thermodynamic properties (density, vapor-pressure depression, activity coefficient, solubility) of aqueous solutions
containing an amino acid or an oligopeptide. The 28 organic compounds considered within this work are glycine,
alanine, serine, proline, hydroxyproline, valine, leucine, arginine, lysine, threonine, asparagine, tyrosine, histidine,
cysteine, methionine, aspartic acid, glutamic acid, R-ABA, R-isoABA, _-ABA, γ-ABA, R-AVA, γ-AVA, diglycine,
triglycine, dialanine, Gly-Ala, and Ala-Gly. If not yet available in literature, amino-acid solubility data and activity
coefficients were determined experimentally. To prove the predictivity of PC-SAFT, osmotic coefficients in aqueous
solutions containing two amino acids (glycine/valine and alanine/ valine) were measured and predicted without
applying any additional model parameters.
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