Determination of the solubility of solid CCl₄ in supercritical CF₄ at subambient temperature

A dynamic experimental apparatus developed for supercritical fluid studies was used to determine the solubility of solid CCl₄ in supercritical CF₄. An on-line quadrupole mass spectrometer was utilized for analysis of the effluent. The direct coupling of supercritical extraction with mass spectrometry offers a quantitative method for the direct determination of the solute mole fraction in the supercritical fluid. Valid data were obtained for two isotherms at 244K and 249K. Solubilities were found to range from 5.1x10^-4 to 2.58x10^-2 mole fraction. These data will broaden the data base to support the testing of new theoretical models for predicting supercritical behavior. This study successfully correlated the data by two different computational approaches: the compressed gas model and the Kirkwood-Buff fluctuation integral model. As the critical point for CF₄ is 227.6 K, these data are among the few supercritical solubility data available at subambient temperature.