Separation of sterol acetates by thin-layer chromatography in reversed-phase systems and on silica gel G — Silver nitrate layers

The analysis of sterols and triterpenoid alcohols by means of thinlayer chromatography has been studied. The occurrence of critical pairs necessitated the use of special systems in order to bring about a separation into “unsaturation classes”. These systems have been prepared by adding bromine to the mobile phase or by impregnating silicagel G layers with silver nitrate. They have been applied to the structural analysis of unknown sterols in complex mixtures of natural origin.