Temperature Dependences of IR Spectral Bands of Humic Substances of Silicate-Based Soils

Temperature-dependent IR spectroscopy capable of revealing specific changes in the band intensities, positions, and shape was used to increase information on humic substances (HS) from soils. Temperature dependences spectra HS isolated silicate-based soils differing contents nature organic matter, chernozem soddy podzolic soil, were investigated by attenuated total internal reflection FTIR mid-IR region (4000–400 cm−1) air within moderate temperature range 25–215 °C (298–488 K) with a step 2.5 °C. The shifts frequency (wavenumber) corresponding maxima integrated intensities built for all major bands. Observed reversible upon heating cooling can be interpreted as forming structures dry state. behavior bands assigned C–H C–C vibrations, characteristic vibrations polyaromatic compounds, carboxylic acids, carboxylates shown, similar same group (symmetric antisymmetric stretches) revealed. Differences trends due different (aliphatic aromatic) functional groups (carboxylic carboxylate) are shown. skeletal differentiates soil types matter. maximum intensity less prone measurement conditions may serve qualitative parameters characterizing composition substances.