Structural-Group Composition and Biological Activity of Humic and Lipid Substances of Brown Coals

Abstract

The samples of brown coal, bitumen and humic acids (HA) extracted from them are characterized by means of elemental and proximate analyses, FTIR, 13С NMR (CPMAS) spectroscopy and gas chromatography-mass spectrometry. The presence of biologically active substances is detected in the extracted bitumen samples. The biological activity of humic preparations in the form of sodium humates and the saponifiable component of the extracted bituminous resin is investigated depending on the structural-group parameters: aromaticity degree (far), the hydrophilic-hydrophobic parameter (fhh), and the parameter depicting the relationship between the aromatic and aliphatic fragments of the organic mass of HA (far/al). It is shown that O-alkylation of the organic mass of coal, followed by debituminizing, changes the structural-group composition of humic acids, causes an increase in the degree of aromaticity and leads to enhancement of the biological activity of HA.