CHEMICAL DEGRADATION OF HUMIC AND FULVIC ACIDS EXTRACTED FROM MEDITERRANEAN SOILS

Humic and fulvic acids were extracted from two Israeli and tour Italian soils and oxidized with alkaline permanganate solution after methylation. Following oxidation, the degradation products were separated by solvent extraction and chromatographic methods and identified by gas chromatography‐mass spectrometry. Major oxidation products were aliphatic, phenolic and benzenecarboxylic acids. In toto, 33 oxidation products were identified. These were essentially the same compounds as those produced by the permanganate oxidation of methylated humic and fulvic acids extracted from soils formed under widely differing climatic and geologic conditions, except that yields of phenolic acids from Mediterranean humic and fulvic acids were lower than those produced under similar conditions from humic materials extracted from other soils. The information provided by chemical degradation suggests that humic and fulvic acids from widely differing soils have similar chemical structures.