Solute focusing in supercritical fluid chromatography

Abstract

AbstractSolute focusing is an important topic in chromatography, but it has not been discussed extensively in the recent supercritical fluid chromatography literature. The purpose of this paper is to review the different methods that have been used to focus solutes in supercritical fluid chromatography. The theoretical basis for phase ratio and partition coefficient focusing is described. Different solute focusing devices that are used in on‐line supercritical fluid extraction and chromatography are shown. The methods and principles of removing the solvent from the solutes prior to the analytical column, and hence reducing band broadening in the column due to the solvent, are discussed in context with the use of a retention gap or a mixing chamber, and in solvent vent injection.