Comparison of the Solid State CPMAS and Solution Carbon-13-NMR Spectra of Humic Acids Extracted from Composted Municipal Refuse

Abstract

Abstract The solution and CPM AS spectra of humic acids extracted from the composted municipal refuse of three Spanish cities (Sevilla, G ranada and Puerto Real) have been obtained at 75.4 MHz. The spectra are discussed qualitatively and the signals assigned to the various chemical struc­ tures forming the humic acids. It is attempted to learn the limits for the quantitative determination of signal areas for the different chemical structures. It is concluded, that aliphatic-and carbohydrate structures contribute most to these compounds.