Detection and visualization methods used in thin-layer chromatography

Abstract

The use of thin-layer chromatography (TLC) for separation, identification and quantification of different organic and inorganic substances is limited by the visualization of the separated and determined substances. In literature, there are innumerable references which present chemical, physical and biological methods of visualization of different kinds of organic and inorganic substances, especially the ones which do not absorb visible light. However, scientists are looking for new, more efficient reagents for a selective visualization of the definite part of a substance or, in some cases, for a specific determination of specific substances. This article describes a different method of visualization of the substances separated on the TLC plates. Special attention was paid to the different chemical reaction applied to obtain colour substrates of the reaction between separated substances and the property of the chosen derivate reagents. Describing different methods of visualization we tried to compare different groups of the determined substance, using different methods of their visualization. The analysis shows, for the first time, that different types of substances need different types of reactions and different types of reagents. The results of the TLC detection of the broad spectrum of the representative classes of organic derivatives are presented in table. The data illustrate the possibilities of TLC differentiation of the organic compounds which contain different active groups. The most unusual effect was obtained during the TLC application of the induced detection reagent. As a matter of fact, some sulphur atoms in their molecules are able to induce the iodine azide reaction.