Separation of 2,4-Dinitrophenylhydrazones by Chromatographic Adsorption

In determining the structure of a number of unsaturated compounds by ozonization, considerable difficulty has been experienced in separating small amounts of low molecular weight carbonyl compounds. The most satisfactory method of isolation is through the 2,4-dinitrophenylhydrnzones, as these are readily formed and are insoluble in water, but in many cases separation of the derivatives by fractional crystallization is unsatisfactory. Separations of a number of 2,4-dinitrophenylhydrazones by chromatographic adsorption have been reported by Strain, by Lucae, Prater and Morris, and by Buchman, Schlatter, and Reims, but only a few of the aliphatic derivatives have been investigated. In the present work, the adsorption of 2,4-dinitrophenylhydrazine and the 2,4-dinitrophenylhydrazones of acetaldehyde, propionaldehyde, acetone, and methyl ethyl ketone was studied on columns of silicic acid-Super Cel