Characterization of Brazilian peat samples by applying a multimethod approach

Peat is a mixture of compounds formed by the decomposition of plant residues and mineral materials that have accumulated at the bottom of ponds and flooded depressions in riverine areas. Due to their extreme heterogeneity and natural variety, the physical and chemical properties of peat can vary widely within or between deposits, and the characterization of isolated samples is still a challenging task that requires the combination of several chemical and spectroscopic methodologies. In this study, the structural characteristics of two Brazilian peat samples were evaluated using scanning electron microscopy (SEM), elemental (CHNS-O) and thermal (TGA) analysis, X-ray diffraction (XRD), and infrared (FT-IR) and solid-state ¹³C-nuclear magnetic resonance (¹³C-NMR) spectroscopies. Although the samples originated from the same peatland, the data showed that the studied samples have distinct chemical properties and that the stage of decomposition played an important role in the differences observed.