AN EMPIRICAL-METHOD TO PREDICT SOLUBILITY IN SUPERCRITICAL FLUIDS

The ability to predict the solubility of analytes in supercritical fluids is important in understanding supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC). In SFE, an analyte must dissolve in the supercritical solvent before it can be extracted. Also, in SFC, the knowledge of solubility characteristics of an analyte is necessary to predict its retention characteristics. Thermodynamic methods using a phase equilibrium approach have been used in the past to predict solubility in supercritical fluids. These methods usually involve complicated calculations and need some experimental data to compute unknown parameters. Here we have developed simple empirical methods for predicting solubility as a function of the prevailing temperature, pressure, and density.