Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

Activity coefficients of glycine, d-alanine and l-valine in aqueous solutions containing MgSO4 at 298.15 K; experimental determination and correlation

Salabat, A.[Alireza], Neshat, S.[Shakiba], Fazlali, A.[Alireza]
Fluid Phase Equilib. 2012, 314, 198-202
ABSTRACT
Water activities of the aqueous ternary systems containing three amino acids glycine, d-alanine or l-valine, and magnesium sulfate, have been obtained at 298.15 K using the isopiestic method. From the water activity data, activity coefficients of the amino acids in these systems were calculated with an equation in terms of the solute molalities. The effect of MgSO4 on the activity coefficient of the amino acids was clarified. The results show that the presence of MgSO4 has a significant effect on the activity coefficient of the amino acids and this effect is different for them. A combination of two models Pitzer-Debye-Huckel and modified Wilson local composition was applied to correlate the activity coefficient data.
Compounds
# Formula Name
1 C2H5NO2 2-aminoacetic acid
2 C3H7NO2 (R)-2-aminopropanoic acid
3 C5H11NO2 L-valine
4 H14MgO11S magnesium sulfate (MgSO4) heptahydrate
5 H2O water
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 5
  • 4
  • (Relative) activity - 5 ; Liquid
  • Mass fraction - 4; Liquid
  • Mass fraction - 1; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Chromatography
  • 9
  • POMD
  • 2
  • 5
  • 4
  • (Relative) activity - 5 ; Liquid
  • Mass fraction - 4; Liquid
  • Mass fraction - 2; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Chromatography
  • 9
  • POMD
  • 3
  • 5
  • 4
  • (Relative) activity - 5 ; Liquid
  • Mass fraction - 4; Liquid
  • Mass fraction - 3; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Chromatography
  • 8