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  • 1
    In: Yugra State University Bulletin, Yugra State University, Vol. 13, No. 4 ( 2017-12-15), p. 7-16
    Abstract: The article reveals the results of studies of the humic acids electronic spectra for various types and kinds of peat in the middle-taiga zone of Western Siberia (Khanty-Mansiysk Autonomous Okrug - Yugra). It was found that the increase in optical density is observed in samples of humic acids which were extracted from the peat with a high degree of decomposition (40-65 %). At the first approximation the interpretation of received electronic spectra gives reason to range humic acids in the order with increasing proportion of aromatic structures share in macromolecules in the following order: 1) peat humic acids having a degree of expansion from 0 to 35 % with the content of a large number of peat-forming plants, where the extinction coefficients vary from 0.039 to 0.054 or sphagnum peat with the same degree of decomposition with the sphagnum containing 95-100 %, where the extinction coefficients have values between 0.030 and 0.042; 2) humic acids of all types and kinds of peat with a degree up to 35 %, where the extinction coefficients are from 0.042 to 0.068; 3) humic acid of peats of all examined types and species with a degree of decomposition from 40 % to 65 %, where the extinction coefficients vary from 0.059 to 0.087. Although the method of electron spectroscopy is an important tool in the study of humification processes in peat, it has a limited informative value due to unresolved spectra. Thus, peat humic acids with various botanical composition and various degree of decomposition are characterized by similar absorption spectra in the visible area in the form of a monotone increasing of absorption in short wavelength interval and differ from each other only by the absorption intensity. Based on the obtained values of the electronic absorption spectra of the GK and the magnitudes of their degree of benzoindole (α), which are calculated by the results of elemental analysis, the obtained information about the ratio of aromatic and aliphatic fragments in the molecules of humic acids, i.e. the information about the structural organization of the molecule . For the conditions of the Khanty-Mansi Autonomous Okrug - Yugra in all samples of peat humic acids did not reveal the dependence of their elemental composition from the types of source of peat, from the peculiarities of their species caused by the location and the specifics of peat formation.
    Type of Medium: Online Resource
    ISSN: 2078-9114 , 1816-9228
    Language: Unknown
    Publisher: Yugra State University
    Publication Date: 2017
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  • 2
    In: chemistry of plant raw material, Altai State University, , No. 2 ( 2022-06-10), p. 271-278
    Abstract: The paper presents the results of a study of the paramagnetic activity of humic and hymatomelanic acids extracted from sapropels of ten small lakes on the right bank of the Ob River and ten small lakes on the left bank of the Ob River (Western Siberia). Quantitative studies were carried out by two methods: the ABS spins method and the method using a double resonator with respect to TEMPO. A comparison of the two methods is presented. The values ​​of the concentration of paramagnetic cents per gram of humic and hymatomelanic acids, as well as the molecular weights of the conditional paramagnetic molecules of humic and hymatomelanic acids were calculated. Based on the results obtained, a conclusion was made about the greater paramagnetic activity of humic acids relative to hymatomelanic acids. Differences in the paramagnetic activity of humic acids and hymatomelanic acids have been established. Three samples from lakes on the right bank of the Ob River and one sample from a lake on the left bank of the Ob River have the greatest differences in paramagnetic activity between HAs and their corresponding HMCs. The concentration of paramagnetic centers in the HAs of these samples is six times higher than in the corresponding MMCs. The contribution of the conjugated aromatic component to the structure of the macromolecules of these HAs is the greatest.
    Type of Medium: Online Resource
    ISSN: 1029-5143 , 1029-5151
    Language: Unknown
    Publisher: Altai State University
    Publication Date: 2022
    detail.hit.zdb_id: 2195031-3
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