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

ABSTRACT

The Solid-liquid equilibrium of indole-3-acetic acid in pure methanol, ethanol, n-propanol, isopropanol, acetone, n-butanol, acetonitrile, chloroform, ethyl acetate, 1,4-dioxane, N,N-dimethylformamide (DMF) and Dimethyl sulfoxide (DMSO) was measured by using a isothermal saturation method from 278.15 to 323.15 K. The solubility data from high to low was ranked as ethyl acetate greater than DMSO greater than DMF greater than n-butanol greater than acetone greater than isopropanol greater than 1,4-dioxane greater than n-propanol greater than ethanol greater than methanol greater than acetonitrile greater than chloroform. Two thermodynamic models (modified Apelblat equation and U h equation) were used to correlate to the solubility values of indole-3-acetic acid in different monosolvents, and the two equations can correlate the experimental values very well. The values of root-mean-square deviations (RMSD) and relative average deviations (RAD) between the experimental and calculated solubility were not exceeding 0.27 e10-6 and 0.75 e 10-2 respectively. In order to study the effect of solvation interaction on solubility, the solute-solvent and solvent-solvent interactions were discussed.