Diffusion rates:

Like gas chromatography, supercritical fluid chromatography is faster than liquid chromatography because of lower viscosity. Diffusion rates in supercritical fluid chromatography are intermediate between those in gases and in liquids. As a result of this, the band broadening is greater in supercritical fluids than in liquids but lesser than in gases. In nutshell, the intermediate diffusivities and viscosities of supercritical fluids may lead to faster separations than are obtained with liquid chromatography accompanied by lower zone broadening than observed in gas chromatography.

This new type of chromatography has started finding applications for a wide variety of materials like natural foods, products, polymers, pesticides, fossil fuels and explosives. Within spite of gaining prominence, a particular technique has not been elaborates in detail in this course. It is still to match in popularity along with other separation techniques involved in the course.