Supercritical fluid chromatography—finding a place in the chromatographers' arsenal?

In the mid- to late 1980s, supercritical fluid chromatography (SFC) was ‘reborn’ as a technique for the 1990s. Supercritical fluids have physical properties (viscosity, diffusivity and density) intermediate between those of licuids and gases. Analyte solubilities are similar to those in some liquid chromatography solvents and the gas-like properties of supercritical fluids make higher resolution or shorter analysis times possible. Applications and experience with a home-built SFC system, as well as methods developed elsewhere, are described. The successes and limitations of the technique are reviewed together with details of the instrumentation. Areas in which SFC may become the procedure of choice include multi-residue methods, non-polar analyses, micro-preparative uses and for difficult extractions. The advances in GC and HPLC technology, however, lead us to believe that SFC will remain a specialist technique, appealing only to a minority of analysts.