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

ABSTRACT

The solubility of pyridoxal 5-phosphate monohydrate (PLP) in four binary mixed solvents (methanol + water, ethanol + water, isopropanol + water and acetone + water) with various compositions were determined at the temperature from 278.15K to 318.15K by the isothermal dissolution equilibrium method under normal atmospheric pressure. The solubility of PLP increases with the increasing temperature and mole fraction of water for the binary mixed solvents ethanol + water, isopropanol + water and acetone + water. For methanol + water, the mole fraction solubility increases with the temperature at a certain solvent composition, yet the solubility has a maximum value around the mole fraction of water fC = 0.8 when the temperature is higher than 308.15K. The experimental solubility was correlated with Wilson model, NRTL model, Apelblat equation and h equation, and the largest value of RMSD is 16.6649 x 10-5. Apelblat equation could best describe the solubility behavior according to the result of AIC analysis. Gmix, Hmix, and Smix in the mixed solutions are calculated. The dissolution process of PLP in the mixed solvents is spontaneous.