Studies on the formation of complex oxidation and condensation products of phenols. A contribution to the investigation of the origin and nature of humic acid. Part I. ─Studies of the reactivity of simple monocyclic quinones

Abstract

In spit of numerous investigations the chemical nature of the humic acids remains obscure, and one result of the defects of our knowledge is the loose application of the term "humic acid" in the literature. For example, the definition given by S. Oden in his excellent monograph, might also cover any "brown or brownish-balck substances of unknown constitution." It has long been known that oxidation of certain tannins and other phenolic compounds yields products (phlobaphenes) resembling humic acids, and it has been plausibly suggested that humic acids and these products of oxidation and condensation are chemically related.