The Carbonyl Group in a Soil Organic Matter Preparation

Abstract

AbstractThe 2,4‐dinitrophenylhydrazone, phenylhydrazone, semicarbazone, and oxime of organic matter extracted from a Podzol Bh horizon were prepared. The four derivatives were analyzed by ultimate analysis, infrared, ultraviolet, and visible spectroscopy, and by X‐ray diffraction analysis.The formation of derivatives was checked by increases in nitrogen content over that in the original organic matter. In the case of the 2,4‐dinitrophenylhydrazone a spectrophotometric method, specific for the derivative, was also used. The number of ketonic C=O groups per mole of original organic matter as determined by analysis of the 2,4‐dinitrophenylhydrazone was 2.1, of the phenylhydrazone 2.5, of the semicarbazone 2.0, and of the oxime 2.2. The presence of C=N bonds, symptomatic of derivative formation, was indicated in the infrared spectra. Evidence for the formation of the derivatives was also provided in some of the ultraviolet spectra and in one visible spectrum. X‐ray diffraction analysis of the original organic matter and of the derivatives indicated that these materials were amorphous.On the basis of reductive acetylation, followed by infrared analysis of the product, and from reductometric titrations it was concluded that this organic matter did not contain measurable amounts of quinone groups and that the groups that had reacted with the reagents were ketonic carbonyl groups.