Catechin sublimation pressure and solubility in supercritical carbon dioxide

Solubility of (+)-catechin in SC-CO2 was measured at several temperatures (313.15, 323.15, 333.15 and 343.15 K) and pressure in the range of 12-26 MPa using ethanol as the co-solvent (5 mol.%). The experimental data were used for the correlation of density dependent solute solubility parameters. The equations of Chrastil, del Valle and Aguilera, Adachi and Lu, Gonzalez, and Mendez-Santiago and Tejawere fitted very well for the solubility of (+)-catechin. The rate of mass loss of (+)-catechin showed that its sublimation pressure is very low, an indication of the stability of the compound. Thermogravimetric analysis was used to determine the sublimation pressure. (C) 2013 Elsevier B.V. All rights reserved.