Thin-layer chromatography of homologues and vinylogues of higher fatty aldehydes, dimethyl acetals, and 2,4-dinitrophenylhydrazones

Abstract

A method is described for the separation of fatty aldehydes, aldehyde dimethyl acetals and methyl esters of fatty acids into classes by two-dimensional thin-layer chromatography. Separations of individual members of long-chain even-numbered saturated fatty aldehydes, their dimethyl acetals and 2,4-dinitrophenylhydrazones and the C 18 unsaturated aldehydes (oleyl, linoleyl, and linolenyl) and their corresponding derivatives were achieved by reversed-phase partition thin-layer chromatography. The critical pairs having identical R F values in the reversed-phase system were separated by adsorption chromatography using silver nitrate-impregnated Silica Gel G plates. With this technique the cis-trans isomers also could be separated as shown by 2,4-dinitrophenylhydrazine derivatives.