ABSTRACT
Just as paper chromatography was displaced by thin-layer chromatography, gas chromatography has been displaced to a significant extent by High-Pressure Liquid Chromatography (HPLC). The real breakthrough in HPLC came with the introduction of packing materials in which a stationary phase was covalently linked to the silica support. In gas chromatography, the separation of components is achieved using suitable stationary phases and perhaps derivatization. In HPLC, it is more common to settle on a single reverse-phase column and achieve the required separations by controlling the partition between the organic stationary phase and the mobile aqueous phase. In the early development of HPLC the two most popular detectors were the refractive index detector and the ultraviolet absorption detector. Fluorimetry has also found great favor as a detection system in HPLC. The chiral properties of the chromatographic system can be invested in the mobile phase rather than the stationary phase.
