Inversion recovery high field solid state (SS) 1H NMR spectroscopy and fast field cycling (FFC) NMR relaxometryhave been applied on dried leaves and leaf-litters from a reafforestated area in central Sicily(Italy) in order to evaluate relaxation properties in both slow (1 x20s2C) and fast (1 x20s2C) motionregimes. Namely, SS 1H NMR spectroscopy (i.e. slow motion regime conditions) revealed that two relaxationcomponents (a fast and a slow one) can be identified in all the leaves and leaf-litter samples. Thefast component was assigned to small sized plant metabolites, whereas the slow one was attributed toslowly tumbling macropolymeric molecules. FFC NMR relaxometry (i.e. fast motion regime conditions)indicated that intra- and inter-segmental motional contributions to plant relaxation occur, dependingon the nature of the plant sample under investigation. The present study represents the first exampleof a combination of high and low resolution NMR techniques for the understanding of the dynamics propertiesof environmentally relevant soft matter such as leaves and leaf-litters. These materials are consideredamong the main contributors for the synthesis of natural organic matter. For this reason, acomprehension of their basic molecular dynamics properties is a crucial point to evaluate their effecton, e.g., carbon cycle, fate of organic and inorganic pollutants, and microbial biomass grow.
|Numero di pagine||7|
|Stato di pubblicazione||Published - 2011|
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