Solubility of organic solutes in ethanol/water mixtures.

The log-linear solubilization model was applied to the experimental solubility data of 109 organic compounds in ethanol/water mixtures. It is found that the extent of solubilization strongly depends on the solute hydrophobicity and the ethanol concentration in the solvent mixture. Patterns of deviation from the log-linear model are related to the structure and hydrophobicity of the solutes. Predictive equations were obtained by regression of the experimental data with solute octanol/water partition coefficient (log Kow). The logarithms of the solubilization and the solute log Kow range over 11 orders of magnitude. The solubilities of chrysene, perylene, benzo[a]pyrene, pentachlorobenzene, and hexachlorobenzene in ethanol/water mixtures were experimentally determined, and the results fit well into the model.