Owen W. Parks

Methods for the isolation and characterization of constituents of natural products: X. New and improved methods for the analysis of carbonyl 2,4-dinitrophenylhydrazones and 2,4-dinitrophenylosazones

Abstract New and improved thin-layer and column adsorption and partition chromatographic systems are described for classifying and separating series of 2,4-dinitrophenylhydrazone and bis(2,4-dinitrophenylhydrazones). Improved and simplified thin-layer adsorption chromatographic methods for separating classes of monocarbonyls (methyl ketones, saturated aldehydes, 2-enals, and 2,4-dienals) and dicarbonyls (α-diketones, α-ketoaldehydes, and glyoxal) are outlined. Partition systems employing a neutral and a basic stationary phase are presented.

Thin-layer chromatography of carbonyl compounds separation of aliphatic carbonyl 2,4-dinitrophenylhydrazones into classes

Abstract A procedure is described for the separation of the 2,4-dinitrophenyldrazine derivatives of aliphatic carbonyl compounds into classes by thin-layer chromatography on magnesia-Celite plates. The four classes examined were the methyl ketones, saturated aldehydes, 2-enals, and 2,4-dienals. Each class produces a characteristic color to the plate which aids in its classification. The procedure, which takes about 1 hour, will readily permit the classification of as little as 9 × 10 −4 μmoles of any of the classes studied.

Thin-layer chromatography of carbonyl compounds: Separation of dicarbonyl bis(2,4-dinitrophenylhydrazones) into classes

Abstract A procedure is described for the separation of the bis(2,4-dinitrophenylhydrazones) of dicarbonyls into classes. The classes investigated were the 2,3-diketones, the α-keto aldehydes, and the dialdehyde, glyoxal. Separation was accomplished on weakened magnesia-Celite plates in an acetone-benzene-MeOH system in approximately 40 minutes. The method permits the classification of as little a 4 × 10−5 μmole of a bis(2,4-dinitrophenylhydrazone). Diketone spots are violet; α-keto-aldehydes and glyoxal are blue.

Methods for the isolation and characterization of constituents of natural products: XI. Preparation of the 2,4-dinitrophenylhydrazone derivatives of fatty acid esters of glycolaldehyde and separation of an homologous series by thin-layer partition chromatography

Abstract An homologous series of the 2,4-dinitrophenylhydrazone derivatives of the glycolaldehyde esters of fatty acids have been prepared. The derivatives are all solids having an absorption maximum at 350 mμ (CHCl3) and a molar extinction coefficient near 20,000. Neutral and alkaline thin-layer partition chromatographic procedures and a thin-layer, silver-ion adsorption system are described for resolving the derivatives.