[Thin-layer chromatographic demonstration of the herbicide zenkor]

Established were the thin-layer chromatography conditions for the demonstration of the herbicide Zenkor as a pure substance and a preparation. Comparative experiments were carried out applying Thomson and Stanley's thin-layer chromatography conditions and the authors' personal ones. Most adequate proved to be the following conditions: sorbent-Kieselgel 60F 254 (Merck); solvent -- chloroform: 1,4-dioxan (9:1); developer -- ultraviolet light (authors' technique). Essential with this method is the preliminary (prior to apply the pure substances on the thin-layer chromatographic plaque) moving of the plaque in the indicated mobile phase (authors' technique). Under these thin-layer chromatography conditions work is made feasible and the method is fast and simple, achieving high sensitivity -- 0.5 mug Zenkor.