Sub-critical fluid chromatography

Achiral (separation of diastereomeric derivatives) and chiral (sepa-ration of enantiomers) chromatography gas chromatography high-performance liquid chromatography super- and sub-critical fluid chromatography thin-layer chromatography... 

Source Reprinted from Influence of the modifiers on the nature of the stationary phase and the separation of carotenes in sub-critical fluid chromatography, in J. Chromatogr., with permission from Friedr Vieweg und Sohn VerlagsgeseUschaft mbH. 

Supercritical fluid chromatography (SFC) refers to the use of mobile phases at temperatures and pressures above the critical point (supercritical) or just below (sub-critical). SFC shows several features that can be advantageous for its application to large-scale separations [132-135]. One of the most interesting properties of this technique is the low viscosity of the solvents used that, combined with high diffusion coefficients for solutes, leads to a higher efficiency and a shorter analysis time than in HPLC. 

Janicot et al. presented the separation of opium alkaloids using sub-critical and supercritical fluid chromatography [20]. Carbon dioxide-meth-anol-triethylamine-water mixtures were used as the mobile phase with packed aminopropyl or bare silica columns. The influence of aminated polar modifiers such as methylamine, ethylamine, and triethylamine was studied. Figure 7.15 shows the separation of six opium alkaloids narcotine, papaverine, thebaine, codeine, cryptopine, and morphine on a Lichrosorb Si-60 column. The method gave comparable results with HPLC. 

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