Detection of Solutes in Preparative SFC

There are a variety of detectors that will be found suitable for the detection of organic compounds in supercritical fluid chromatography. Carbon dioxide is the most widely used fluid and has the advantage of being transparent in the ultraviolet part of the spectrum to 190 nm. Variable wavelength UV absorption detectors used for liquid chromatography may be employed for SFC but they must incorporate a cell that can withstand the very high pressures employed in the technique. A number of UV detector manufacturers produce suitably modified instruments for use with SFC. 

Sensitivity for the eluted solute peak is often much larger than with analytical SFC. In fact, as often happens in preparative HPLC, the variable wavelength UV detector must be de-tuned away from the wavelength of maximum absorption of the eluting species to prevent overload of absorption. For the vast majority of cases when using modified carbon dioxide mobile phases there is no need to look further than the simple UV detector. 

However, there are other detectors which have been demonstrated as having some specific advantages over UV absorption in certain cases. Detectors that have been 

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