FTIR photoacoustic spectroscopy for identification and assessment of soil components: Chernozems and their size fractions

Petr K Krivoshein; Dmitry S Volkov; Olga B Rogova; Mikhail A Proskurnin

doi:10.1016/j.pacs.2020.100162

FTIR photoacoustic spectroscopy for identification and assessment of soil components: Chernozems and their size fractions

Photoacoustics. 2020 Jan 22:18:100162. doi: 10.1016/j.pacs.2020.100162. eCollection 2020 Jun.

Authors

Petr K Krivoshein¹, Dmitry S Volkov^{1

2}, Olga B Rogova², Mikhail A Proskurnin¹

Affiliations

¹ Chemistry Department, M.V. Lomonosov Moscow State University, Leninskie Gory, 1-3, GSP-1, Moscow, 119991, Russia.
² Department of Chemistry and Physical Chemistry of Soils, V.V. Dokuchaev Soil Science Institute, Pyzhevsky Per., 7/2, Moscow 119017, Russia.

Abstract

FTIR photoacoustic spectroscopy was used to approach inorganic matrix components and organic-matter constituents of chernozem size fractions (1-5000 μm, by dry sieving) with a different history of use (from intact steppe to permanent bare fallow, a continuous long-term field experiment). The conditions of FTIR photoacoustic measurements in continuous-scan modes were compared with attenuated total reflection measurements, the advantages of photoacoustic measurements resulting from a higher intensity of the incident radiation and signal-generating volume were discussed. Overtone peaks of quartz as a soil matrix component at 2000-1700 cm^-1 were selected as a possible internal-standard (guide) bands for the comparison of photoacoustic spectra. For different land-use samples, differences in the composition were found, which are differently manifested in normalized spectra of size fractions, with millimeter-size, 20-100 μm, and silt fraction bearing the maximum information.

Keywords: Attenuated total internal reflection FTIR spectroscopy; Chernozem; FTIR photoacoustic spectroscopy; Soil composition.