Thin-layer chromatography of dyestuffs on polyamide and “silver nitrate” layers

Abstract The chromatographic behaviour of fat-soluble dyestuffs in thin-layer chromatography has been studied. Various types of adsorbents such as silica gel G, Kieselguhr G, aluminium oxide G, polyamide and silver nitrate-impregnated silica gel were tested. When using layers of polyamide and aqueous solvents (mixtures of alcohols, acetone, water, etc.) as mobile phase some dyestuffs are separated according to the principle of reversed-phase partition chromatography. By using the solvent mixture light petroleum—benzene—acetic acid (1:1:0.5) a polar-phase partition chromatography was obtained.