Further data on a histochemical reaction as applied to the thin-layer chromatography of sterols

A method for the characterization of sterols on silica gel G layers is proposed. After the chromatograms have been sprayed with a permanganate-sulphuric acid oxidative reagent and the reaction has been terminated with sodium hydrogen sulphite, the plates are sprayed with the colour-developing reagent (an acid solution of alcian blue or toluidine blue). The plates are also viewed under UV radiation (254 and 366 nm). Only 3 of the 28 sterol samples assayed (spot content 8 mug) did not show positive reactions after oxidation, which suggests that this step can be used as a "universal" detection method for sterols. After staining the plate, several sterols are shown to be easily differentiated from one another. The exposure of the plates to UV radiation assists characterization. In general, the reaction exhibits satisfactory sensitivity for the qualitative and differentiating detection of sterols; it is also rapid and easy to carry out.