Supercritical Fluid Chromatography (SFC) is a technique with properties between that of gas chromatography and liquid chromatography because the mobile phase is a substance maintained at temperature and pressures above the critical point, the point where the substance can be condensed to a liquid. The supercritical fluid has intermolecular interactions that are smaller than the average kinetic energy of the molecule. The concentration of the mobile phase may be increased substantially over that in gas chromatography, which in turn increases the interactions between the mobile phase and the analyte, speeding elution times. At the same time the viscosity of the mobile phase remains low because intermolecular interactions are minimal. Carbon dioxide is the most common SFC mobile phase. Supercritical fluid chromatography.