Solubility Measurements of Chloramphenicol in Supercritical Fluid CO2 Using Static Solubility Apparatus Interfaced with Online Supercritical Fluid Chromatography

The solubility of chloramphenicol in pure supercritical fluid carbon dioxide (SF-CO2) has been determined using a continuously stirred supercritical solubility vessel (SSV) directly interfaced with online supercritical fluid chromatography (SFC) using a single valve interface. Solubility measurements were performed at two temperatures of 313 and 333 K with pressures ranging from 10 to 26 MPa. For each individually loaded sample, a series of increasingly more saturated chloramphenicol solutions were prepared in situ by ramping the SF-CO2 pressure within the SSV in 2 or 3 MPa steps. Once equilibrium dissolution was established at each pressure step value, online SFC solubility measurements were performed. The combined SSV–SFC instrumentation and methodology enabled the rapid acquisition of chloramphenicol SF-CO2 solubility data. Chloramphenicol exhibited limited solubility in SF-CO2, providing mole fraction solubility values of 4.9 × 10–6 to 9.9 × 10–6 within the experimental range studied. All sets of SSV–SFC experimental solubility values obtained for chloramphenicol were successfully correlated in accordance with the semiempirical SF-CO2 density-based models developed by (i) Méndez-Santiago and Teja (MST) and (ii) Bartle.