The observation of a wholesale flake precipitates indicating the presence of polyuronides
Stoichiometric depolymerization of polyuronides
and glycosaminoglycuronans to monosaccharides following reduction of their carbodiimide-activated carboxyl groups.
This is because the POM-C or light fraction C, which is present as transient binding organic matter (polysaccharides, polyuronides
, mucilages, microbial debris) and temporary binding organic matter (roots, fungal hyphae), disappears at a much faster rate than the whole SOM (Greenland and Ford 1964; Dalal and Mayer 1986d; Chan 1997).
The fast-relaxing subspectrum (47% of the signal) appeared to consist mostly of disordered/amorphous polysaccharides and polyuronides
(carbonyl and O-alkyl peaks), protein (carbonyl, N-alkyl, and alkyl peaks), and lignaceous material.