Two-dimensional thin-layer chromatography of Dns-amino acids on reversed-phase silica gel

Ready-for-use reversed-phase high-performance thin-layer chromatographic plates were used for the separation of Dns-amino acids. The development was performed by using methanol-2% acetic acid (75.25) or methanol-0.01 M Na2HPO4 (75:25). Reversed-phase plates were used also for adsorption chromatography using a non-aqueous solvent system such as benzene-chloroform-acetic acid (50:48:2) or n-heptane-ethyl acetate-acetic acid (65:33:2). Good separations were achieved by using both principles in the two-dimensional arrangement.