Supercritical fluid chromatography enhanced selectivity

Many of the same properties that make supercritical fluids advantageous in chromatography also enhance their ability to extract compounds from within a sample matrix.(4) Also, since the solubility of most compounds is dependent on the density of the supercritical fluid, selective extraction is possible. (J5) These properties are well known, and have been exploited in some cases where the extraction was formerly done with a liquid. In many cases, the quality of extract is higher, and extractions are of higher efficiency than with liquids. Supercritical fluids, especially CO, are also often less expensive, less toxic and less flammable than their organic liquid phase counterparts. 

The greater selectivity of adsorption chromatography for compounds of different chemical types may be extended using supercritical fluids (SFs) as the mobile phase [96-99]. In normal GC the carrier gas does not interact significantly with the stationary phase, but when it is above it s critical temperature and pressure strong interactions occur. This makes the analytes being separated appear more volatile due to enhanced molecular interaction with both the mobile phase and stationary phase which has surface... 

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