ALKALINE CUPRIC OXIDE OXIDATION OF ROOTS AND ALKALINE-EXTRACTABLE ORGANIC MATTER OF CHERNOZEMIC SOILS

Alkaline cupric oxide oxidation was performed on roots of three grass species, on humic substances from three Chernozemic soils, and on three known compounds. The three grass species were Stipa comata Trin. & Rupr., Stipa spartea Trin. var. curtiseta Hitchc, and Festuca scabrella Torr., the three Chernozemic soils were Brown, Dark Brown and Black, and the three known compounds were vanillin, p-hydroxybenzaldehyde, and syringaldehyde. The intent of the study was to obtain a qualitative overview of the set of ethyl ether-soluble products. The gas chromatographic patterns were, therefore, qualitatively assessed and only some of the major peaks were tentatively identified. The ethyl ether-soluble fraction represented only up to 5.7% of the total root C. Most of the compounds identified in the root digests were also present in digests of the alkaline-soluble humic substances. There were quantitative differences for each chromatographic peak among root species, among time of sampling and growth location, and among extraction procedures of humic substances. The oxidation of the three known compounds in turn led to a number of compounds. The CuO-NaOH oxidation may thus cause alterations in similar compounds released from the original structure which will lead to either inflated or deflated yields of compounds that were part of the original structure.