Liquid Chromatography - Reversed Phase

Liquid chromatography (LC) was first developed around the turn of the twentieth century and is defined by the International Union of Pure and Applied Chemistry (IUPAC) as a means of physically separating components in mixtures by distributing the components between two phases. One of these phases is moving and percolates through the second, which is stationary. In LC the moving phase or mobile phase is a liquid. The technique has since grown enormously to include the areas of capillary LC, microbore LC, high performance LC (HPLC), and preparative LC. In the following discussion we shall detail the process of solute retention in the technique referred to as reversed-phase liquid chromatography. This is the most widely employed form of liquid chromatography, and in 1997, more than 80% of all HPLC separations were reportedly reversed phase. In this mode of chromatography the stationary phase is a non-polar adsorbent, while the mobile phase is more polar than the stationary phase.