Supercritical fluid chromatography is a chromatographic technique that uses supercritical fluids as the mobile phase It has few advantages over gas chromagraphy that is gas chromatography is suitable only for volatile solvents as mobile phase.
Solubility with the capability to use nonselect gas phase detector is the major advantage of supercritical fluid chromatography(SFC).
By changing the pressure the solvating power can be adjusted . Above the critical temperature and critical pressure point ,no phase change takes place , the substance acts as a supercritical fluid . SCF is a fuid obtained by heating above the critical temperature and compressing above the critical pressure. SC fluid described by the term compressed pressure. the density of the SC fluid increases as the pressure in system increases ,thus its solvating power increases. CO2 is the mobile phase which is mostly used . a modified fluid which is completely miscible organic solvent with CO2 is known as second fluid. The analyte which is only soluble in aqueous phase is a poor candidate for the SFC.
Separation of analytes from solvents is fast and easy.
SFC have solvating power similar to liquid organic solvents.
Polarity can be changed by adding modifiers to a SCF (like methanol to CO2 )
Disposal costs are very less, Supercritical fluids are cheap, simple, safe. (1,2)