Characterization of 1,1,1,2-Tetrafluoroethane and Carbon Dioxide Binary Mobile Phases with Polymeric Columns Using Linear Solvation Energy Relationships

In this study, the chromatographic properties of binary carbon dioxide/1,1,1,2-tetrafluoroethane (HFC-134a) mobile phases on a polymeric stationary phase are examined. Retention of various analytes, as a function of mobile phase composition, is dependent upon the physicochemical properties of the analyte. The specific intermolecular interactions between various solutes and the mobile and stationary phases responsible for the retention behavior are probed using linear solvation energy relationships. Using this methodology, it is apparent that solute hydrogen bond donating ability is the dominant factor dictating retention in these systems. Other solute properties, such as dipolarity/polarizability, hydrogen bond accepting ability, and excess molar refraction, have much smaller effects on retention.