report a study of the use of 2,4,6-triphenylpyrylium salts as derivatization reagents for the simple detection of sulfide ions in thin-layer chromatography (TLC). The principle of the presented method is based on the transformation of 2,4,6-triphenylpyrylium compounds into the parent thiopyrylium derivatives upon reaction with sulfide ions. The derivatization reaction took place in a tube or directly