Chromatography of Dns derivatives on pre-coated high-performance thin-layer chromatographic plates

Abstract

5-Dimethylaminonaphthalene-1-sulphonyl (Dns) derivatives of amino acids and amines have been separated on high-performance thin-layer chromatographic (HPTLC) plates. Due to interaction of the matrix, especially with polar compounds and solvents, relative mobilities on HPTLC plates differ from those on silica gel G layers; as these differences are small for non-polar compounds, HPTLC plates can be used for the determination of aliphatic polyamines and allied compounds when using known solvent systems for separation. This paper describes (i) solvent systems for the two-dimensional separation of Dns-amino acids that are suitable for HPTLC and normal silica gel plates, (ii) a horizontal-development technique that allows preparation of several two-dimensional chromatograms on a 10 × 10 cm plate, and (iii) an extraction procedure for the optical evaluation of compounds separated by thin-layer chromatography. The obvious advantages of HPTLC plates are rapid development, high capacity and increase in the signal-to-noise ratio.