ABSTRACT

The solubility of gallic acid, vanillin, syringic acid, and protocatechuic acid in aqueous solutions of various concentrations of sodium sulfate was determined from (293.15 to 318.15) K at atmospheric pressure using a thermostatted reactor and HPLC analysis. Results showed a salting-out effect on the solubility of the tested phenolic compounds. The solubility data were accurately correlated to a semiempirical equation. The temperature dependence of the solubility data were used to estimate thermodynamic properties such as Gibbs free energy (AsolGo), molar enthalpy of dissolution (AsolHo), and molar entropy of dissolution (AsolSo).

Compounds

#	Formula	Name
1	C7H6O5	3,4,5-trihydroxybenzoic acid
2	C8H8O3	vanillin
3	C9H10O5	4-hydroxy-3,5-dimethoxybenzoic acid
4	C7H6O4	3,4-dihydroxybenzoic acid
5	Na2O4S	sodium sulfate
6	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 6	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 1	Chromatography	6
POMD	2 6	Mole fraction - 2 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 2	Chromatography	6
POMD	3 6	Mole fraction - 3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 3	Chromatography	6
POMD	4 6	Mole fraction - 4 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 4	Chromatography	6
POMD	1 6 5	Mole fraction - 1 ; Liquid	Molality, mol/kg - 5; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 1	Chromatography	24
POMD	2 6 5	Mole fraction - 2 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 5; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 2	Chromatography	24
POMD	3 6 5	Mole fraction - 3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 5; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 3	Chromatography	24
POMD	4 6 5	Mole fraction - 4 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 5; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 4	Chromatography	24

Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Solubility of Gallic Acid, Vanillin, Syringic Acid, and Protocatechuic Acid in Aqueous Sulfate Solutions from (293.15 to 318.15) K

Noubigh, A.[Adel], Cherif, M.[Mourad], Provost, E.[Elise], Abderrabba, M.[Manef]

ABSTRACT