The oganic carbon content, δ13С values (‰) and content of polycyclic aromatic hydrocarbons (PAHs) was determined in pedogenic material of Batagay ice wedges.

PAHs luminescence and bituminological analysis was carried out in the laboratory of carbon materials of the biosphere of the Department of Landscape Geochemistry and Soil Geography of the Geography Department of Lomonosov Moscow State University. The analysis was carried out in a hexane extract by spectrofluorimetry (Shpolsky spectroscopy) with a cryogenic console (Florovskaya, 1957; Pikovskii et al., 2017). The analysis of PAHs was carried out on a spectrofluorimetric complex created on the basis of the Fluorat-Panorama instrument (Lumex, St. Petersburg), supplemented with the LM-3 monochromator and the CRIO-1 cryogenic console. The carbon isotope composition of lipid compounds was determined in isotope laboratory of the Geography Faculty of Lomonosov Moscow State University using mass spectrometer Delta-V Plus (Prof. Vasil'chuk and Dr. Budantseva) with a standard option element analyser EA 1112 HT O/H–N/C. For measurements the international standards IAEA–CH–3, IAEA–CH–6, IAEA-600 and USGS-24 were used. The accuracy of the δ13С determination was ±0.2‰.Lipids were extracted from soil inclusions in ice wedges by cold extraction with chloroform and hexane (Korchagina and Chetverikova, 1976). Samples of pedogenic material were passed through a sieve with 0.25 mm pores and treated with a solvent (chloroform and hexane) in a ratio of 5 ml of solvent per 2 g of sample. Twenty samples were treated with chloroform, 5 of them were simultaneously treated with hexane.Chloroform was chosen as it provides full extraction of soil lipids. Samples were allowed to stand in glass tubes for a day, before the supernatant was decanted and concentrated by evaporation in glass bottles in the shade at room temperature. The concentrated solution was pipetted into tin capsules and evaporated to an air-dry state.PAH: polycyclic aromatic hydrocarbons