Analysis of Croton Oil by Reversed-Phase Overpressure Layer Chromatography

Abstract

Although the first paper on overpressure-layer chromatography (OPLC) (also known as overpressured thin layer chromatography) appeared over 10 years ago (Tyihák et al. 1979), many applications of this planar chromatographic technique have since been published (Witkiewicz and Bladek 1986; Tyihák 1987). OPLC involves many of the elements of thin layer chromatography (TLC), but, unlike the latter technique, the vapor phase is completely eliminated so as to leave the sorbent layer covered with an elastic membrane under external pressure. When forced by a pump, the mobile phase migrates through the sorbent layer due to the cushion system at overpressure (Tyihák et al. 1979; Witkiewicz and Bladek 1986; Tyihák 1987). Details of the apparatus required for OPLC, as well as of the theoretical basis of this technique, have appeared in the literature (Hauck and Jost 1983; Witkiewicz and Bladek 1986; Tyihák 1987). Higher efficiencies, increased solute loading capacity, and reduced solvent development times can be obtained by OPLC when compared to capillary controlled systems such as TLC. If large numbers of samples have to be analyzed, or if some of the components in a mixture are difficult to detect, OPLC also has advantages over high-performance liquid chromatography (HPLC) (Witkiewicz and Bladek 1986; Tyihák 1987). In addition to being used for the analytical separation of organic molecules, OPLC is very useful for their preparative purification (Nyiredy et al. 1986; Erdelmeier et al. 1987).