Natural organic matter (NOM) represents an ubiquitous, very complex mixture of organic and (a few) inorganic constituents and occurs in terrestrial, limnic and marine ecosystems. NOM plays immensely important roles in the natural world, and it is a key refractory constituent of the global carbon and other element cycles. The characterization and structural analysis of NOM, which features a substantial extent of both polydispersity and molecular heterogeneity, is most demanding with respect of methodology and concepts and requires the use of complementary techniques capable of delivering molecular-level precision data.
NMR spectroscopy combines far reaching, isotope-specific definition of chemical environments and unsurpassed detailed information concerning the short range molecular order with the most reliable quantification of any organic structural spectroscopy method. Mass spectra provide unsurpassed resolution and provide thousands of molecular formulae in a single experiment. By use of multinuclear one and two dimensional NMR experiments, in-depth information concerning carbon backbone, functional groups and interactions of NOM of various origin became available. These findings considerably advance the understanding of NOM functions in these ecosystems. Four key examples were covered in-depth: (1) the binding of cadmium to NOM from an aquatic source, (2) the molecular-level precision analysis of fulvic and humic acids in soil, (3), the computation of aromatic substitution patterns of NOM from NMR data, and (4) the characterization of a major novel key constituent of NOM, namely CRAM (carboxylic-rich alicyclic molecules) which is most likely derived from terpenoids.
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Natural organic matter (NOM) represents an ubiquitous, very complex mixture of organic and (a few) inorganic constituents and occurs in terrestrial, limnic and marine ecosystems. NOM plays immensely important roles in the natural world, and it is a key refractory constituent of the global carbon and other element cycles. The characterization and structural analysis of NOM, which features a substantial extent of both polydispersity and molecular heterogeneity, is most demanding with respect of me...
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