ABSTRACT
The development of high-field superconducting magnets and of Fourier transform techniques has made possible the application of solution Nuclear magnetic resonance (NMR) to humic materials from soils, composts, aquatic environments, sediments and coals. Although humic acid and fulvic acid constitute soluble fractions, and are defined by their solubility in base, and at all pH values, respectively, they are often not soluble to the 50-100 mg/ml. levels desirable for C NMR. Solution C NMR can provide unparalleled structural information on humic substances from many different sources. The H NMR spectra of humic materials also have features indicating a wide range of chemical structures. A combination of chemical and NMR techniques can be used to extract more information from C spectra.
