The physical characteristics exhibited by supercritical fluid include a diffusion coefficient of dissolved molecules that is a hundred times greater than it is in liquid and a viscosity that is at least one figure smaller. A supercritical fluid chromatography system, which employs such a medium as a mobile phase, can be expected to serve as a separation analysis method that can rapidly perform separation without any drop in separation efficiency, even at fast flow rates, due to a rapid mass transfer inside the column when compared with high-speed liquid chromatography that uses liquid as the mobile phase.
In addition, when carbon dioxide is used as the medium, gasification will occur simply by keeping the separated and fractionated sample at a constant temperature, making this one of the techniques capable of highly efficient refining with few post-processing hassles, such as elimination solvents after preparative isolation. This offers a host of advantages, including cost savings related to the expense of purchasing solvent and discarding organic solvents, and high throughput analysis and preparative isolation due to rapid separation over a short period of time. As a gradient elution technique, SFC is able to vary the three parameters of pressure, temperature, and modifier solvent volume. It can be effectively used when separating oligomers and constituents with differing characteristics. (The temperature gradient requires the use of a column oven that continuously varies temperature over time.)
Ces détecteurs HPLC doivent être équipés d'une cellule Haute Pression pour fonctionner en SFC/SFE