N.P. Avvakumova, M.A. Krivopalova, I.V. Fomin, A.V. Zhdanova

Natural biologically active substances of low- mineralized silt sulphidic muds were researched. Authors obtained two fractions of humus acids of peloids: humic and fulvic acids, using the described technique in this work. Content of basic elements, ash value were defined and atomic ratios were calculated for the synthesized compounds. Set of the obtained data confirm an accessory of these compounds to the group of humus acids. The analysis of infrared spectra of humic and fulvic acids allows to identify unsaturated olefin and aromatic fragments, the hydroxyl groups of phenolic and alcoholic nature and carboxylate ions in their composition. Authors revealed some structural features of humus acids of peloids in comparison with humus acids of soils - for example, formation of humic and fulvic acids peloids in the conditions of high degree of a hydromorphism leads to an increase of the proportion of unsaturated aliphatic components. Qualitative comparison of relative intensity of pass bands of the spectra allows to assert that aliphatic chain with a considerable quantity of alcohol groups such as carbohydrates prevail in fulvic acids whereas humic acids contain the conjugated aromatic structures with with a high content of carboxyl groups. Fulvic and humic acids of peloids have a similar molecular structure with different fractions of aliphatic and aromatic fragments according to infrared spectroscopic analysis.