Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The solubility of aloe-emodin in seven pure solvents namely water, methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, and 1-pentanol was measured by a static analytic method. The measurements were carried out over the temperature range from (278.15 to 318.15) K at 5 K intervals under atmospheric pressure using a UV/vis spectrophotometer analysis. The effects of experimental temperature and solvent type on the solubility are discussed. The relative solubility of aloe-emodin in seven solvents was determined in elevated order to be xwater less than xmethanol less than xethanol less than x2-butanol less than x1-propanol less than x1-butanol less than x1-pentanol. The experimental result shows that 1-pentanol could be a suitable solvent for industrial preparation of aloe-emodin. The experimental solubility values were correlated with the modified Apelblat and .lambda.h models. It was found that the two empirical thermodynamic models can satisfactorily correlate the solubility of aloe-emodin in the seven solvents over the range of temperature studied.