Differentiation of hydrophobic and hydrophilic components of humic substances in the Selenga river delta soils

The article considers soil humic substances as a multicomponent system of amphiphilic (showing both hydrophobic and hydrophilic properties) substances. We have carried out fractionation of humic substances from soils of various genesis (meadow and meadow-boggy) by hydrophobic interaction chromatography on octyl sepharose CL-4B. This method fractionates humic and fulvic acids into separate components that differ in their ability to enter into hydrophobic interactions with the gel matrix. The results show that a higher percentage of hydrophobic macromolecules has been found in the humic substances of meadow soils than in other samples (humic acids of meadow-boggy soils and fulvic acids). The fulvic acid sample has shown weaker hydrophobic interactions than the humic acids.