### Abstract

Samples of humic substances (HS) of black earth and compost and their chromatographic fractions (A, B, C + D) have been obtained by a combination of gel-chromatography and electrophoresis aimed to decrease their dimensions and to increase the electrophoretic mobility and studied by small-angle neutron and synchrotron X-ray scattering methods. It has been showed that the initial HS preparations and their fractions are polydisperse, the low-molecular mass fractions (B, C + D) being more polydisperse than the high-molecular mass fraction (A). It has been found that HS of black earth are enriched with low-molecular mass fractions as compared to the HS of compost. Analysis of particle conformation permitted us to conclude that HS macromolecules in A and B fractions of black earth have a branched coiled structure. At the same time, the conformation of macromolecules in the C + D fraction of black earth and in all compost fractions has a rod-like (elongated) structure. Investigation of the large-angle portion of scattering curves both of initial HS specimens and their fractions has showed that all the studied compounds belong to the class of mass fractals.

Original language | English |
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Pages (from-to) | 603-614 |

Number of pages | 12 |

Journal | Surface Investigation X-Ray, Synchrotron and Neutron Techniques |

Volume | 15 |

Issue number | 4 |

Publication status | Published - Jan 1 2000 |

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### ASJC Scopus subject areas

- Surfaces, Coatings and Films

### Cite this

*Surface Investigation X-Ray, Synchrotron and Neutron Techniques*,

*15*(4), 603-614.