Paper Chromatographic Identification of the 2 : 4-Dinitrophenyl-Derivatives of Aliphatic Amines

Abstract

DURING recent work on the structure of bacitracin A, the identity of small amounts of aliphatic amines was confirmed by allowing them to react with 1 : 2 : 4-fluorodinitrobenzene¹ and chromatographing the resulting dinitrophenyl derivatives on paper². A number of primary aliphatic amines can readily be separated by chromatography on paper³, or by ionophoresis on paper at pH 7 using collidine acetate buffer^2,4, and the spots revealed with ninhydrin. Schwyzer has separated certain primary, secondary and tertiary amines by paper chromatography, the spots being revealed by spraying with an indicator⁵. However, in view of the fact that the technique described here will give further evidence of the nature of a mixture of primary and secondary amines and ammonia, and that 0.5 µgm. or less of the dinitrophenyl-amines can be detected on the chromatograms under ultra-violet light, it seemed worth while to place it on record.