Humic acid—II

The action of water and acids on “humic acid” (HA) is described, and it is concluded that HA is a complex of a polycyclic aromatic “core” responsible for the ESR spectrum which is attached to polysaccharides, proteins, relatively simple phenols and metals. Oxidation of the “core” with permanganate and decarboxylation of the resulting acids gives a neutral oil containing β-methylnaphthalene, anthraquinone, fluorenone, xanthone and homologues. Zinc dust distillation of the “core” gives a yellow distillate containing naphthalene, anthracene, benzofluorene, pyrene and benzopyrenes, perylene and benzoperylene, triphenylene, chrysene, coronene, carbazole, acridine and benzoacridines, and possibly complex benzofurans together with homologues and hydrogenation products. The products from the permanganate oxidation and the zinc dust distillation, obtained in very small yields, were separated by chromatography into fractions which were analysed by UV and mass spectrometry. The nature of attachment of the polysaccharides, proteins, phenols and metals to the polycyclic aromatic core is discussed.