Humic matter as a conceptual mixture of model compounds: an application of the molecular mixing model to mumic acids from a Mediterranean semiarid wetland (Las Tablas de Daimiel, Central Spain)

Abstract

Molecular mixing model (MMM) represents a practical, empirical approach proposed by Nelson [1], and further developed by Nelson and Baldock [2] in an attempt to describe the molecular composition of natural organic matter from quantitative data based on the different carbon types determined by 13C-NMR spectroscopy. These authors have shown that detrital organic matter, either terrestrial or aquatic, coming from different sources, could be described in terms of up to six generic organic components (carbohydrate, protein, lignin, lipid, “pure carbonyl”, and char), assuming that the experimental spectra of the organic matter could be reproduced from a linear combination of spectra of these six generic organic components.