A Chemical and Spectroscopic Characterization of some Synthetic Analogues of Humic Acids

Abstract
Fourteen analogues of humic acids (“HA's”) were synthesized from phenols, quinones, and salicylic acid by methods described in the literature. Elemental and functional group measurements, and infrared and electron spin resonance spectroscopy, indicated that seven of these “HA's” were in general similar to natural HA's. These “HA's” were methylated and further investigated by chemical degradation. Identities and quantities of the methylated degradation products resembled those from natural HA's treated in the same way. Thus, “HA's” resulting from oxidative polymerizations of salicylic acid, catechol, hydroquinone, and pyrogallol, under a variety of reaction conditions, appear to be suitable for investigations of interactions of humic materials with pesticides, enzymes and other N‐compounds. Some of these synthetic “HA's” can be readily prepared in any laboratory and, in contrast to microbially‐synthesized “HA's”, also as N‐free analogues.