Chemical and Spectroscopic Characterization of the Humic Substances From Sandstone-Derived Rock Fragments

Spodosol–Histosol evolution in the Krkonoše National Park (CZ)

“…The FT-IR spectra showed a shoulder at 1546 cm À 1 (stretching of amide II) that became more pronounced in the deeper horizons of the profiles MD1, MH2 and MH3 (Fig. 4), suggesting an incorporation of proteinaceous residues in the HA structure (Agnelli et al, 2000). The HA from all horizons of MH4 and MH5 show the presence of organic substances with a low degree of transformation and no bands due to amides are found in the corresponding FT-IR spectra (Figs.…”

Influence of animal manure application on the chemical structures of soil organic matter as investigated by advanced solid-state NMR and FT-IR spectroscopy

“…However, spectral differences were observed between MHA and CaHA fractions. The FT-IR bands are interpreted based on previous reports with humic substances (Francioso et al, 1996;Agnelli et al, 2000;Olk et al, 2000;Tan, 2003;He et al, 2006b).…”

“…The band at 1125 cm − 1 , pronounced in the MHA spectra, is attributed to the C-O vibration of alcohol and ether groups . The bands at 1075-1028 cm − 1 have frequently been assigned to alcoholic and polysaccharide C-O stretching or SiO 2 impurity (Giusquiani et al, 1998;Agnelli et al, 2000;Olk et al, 2000;Tan, 2003). We would like to attribute them, at least partially, to phosphate groups, as they correspond to the abundance of P in the samples (Francioso et al, 1996;He et al, 2006b).…”

Differences in humic acids structure of various soil types studied by DRIFT spectroscopy

“…This spectrum has analogical bands as humic acids spectra, but their intensities differ. There is very apparent aromatic ring breathing at 1600 cm -1 (covered in HAs spectra) and sharp intensive peak of aromatic moieties in lignin at 1512 cm -1 , sharp also in spectra of the H Agnelli et al (2000). The dominant peak at 1270 cm -1 is characteristic for guaiacyl ring breathing (Ferrari et al 2011).…”

“…NMR) which can provide more detailed information about soil organic matter, or humic substances and their structure and modification in space and time (e.g. Agnelli et al 2000;Chai et al 2007;Liu et al 2008;Ferrari et al 2011). The method of diffuse reflectance spectroscopy (DRIFT) enables measurement of separated humic acids (HAs) and fulvic acids (FAs) in their pure forms without diluting (for example by potassium bromide).…”