Chapter 16 Supercritical Fluid Chromatography

Unexpected retention and efficiency behaviors in supercritical fluid chromatography: A thermodynamic interpretation

“…Supercritical fluid chromatography (SFC) possesses three main advantages over liquid chromatography (LC) and very highpressure liquid chromatography (vHPLC): (1) it is environmentfriendly (inertness of gaseous carbon dioxide), (2) it can be operated at very high linear velocities under conventional system pressures (<600 bar) due to the very low viscosity of SFC mobile phases [1][2][3], and (3) the strength of SFC mobile phases can be tuned over a large range of solvent strength by adjusting independently temperature, pressure, and content of organic modifier. For these reasons, its interest has been continuously growing over the last decade and supported by the manufacture of new high-performance SFC systems [1].…”

Bridging the gap between gas and liquid chromatography

“…Supercritical fluid chromatography (SFC) is a priori particularly attractive because 1) the viscosity of supercritical fluids (mostly carbon dioxide) is one order of magnitude smaller than that of liquid water, 2) carbon dioxide is an environment-friendly solvent, and 3) the elution strength of supercritical fluids can be easily tuned by independently adjusting its temperature, pressure, and the content of organic solvents [6][7][8] . Consequently, high-molecular-weight compounds can be easily separated at ambient/moderate temperatures (30-60 o C) by applying either high back column pressures (>2000 psi) or high contents of organic solvent up to 40% in volume 9,10 . In such conditions, the density of the mobile phase is large and the separation mechanism is similar to that encountered in LC 11,12 so that retention decreases with increasing temperature.…”