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Nová možnost charakterizace disociačního chování supramolekulárních elektrolytů: výsledky získané pro standardy a referenční vzorky International Humic Substances Society pomocí coulometrie

dc.contributor.authorKlučáková, Martinacs
dc.identifier.citationChemical and Biological Technologies in Agriculture . 2021, vol. 8, issue 1, p. 1-10.en
dc.description.abstractBackground: Humic substances can be considered as polyelectrolytes with supramolecular character and complicated behaviour in water environment. The fractions of humic substances dissolved in water are the most active ones and determinative for their functioning in nature, where the proton-binding and dissociation ability play a crucial role. The dissociation behaviour of humic and fulvic acids can be affected by different circumstances including their concentration which is directly connected with the molecular organization of humic particles in solution and the accessibility of their ionizable functional groups. This study is focused just on these active fractions and their dissociation behaviour in the dependence on their content in studied system. Results: Standards and reference samples of International Humic Substances Society were used. Flow-through coulometry was used to determine the total content of acidic functional groups in fulvic solutions and humic leachates. The amount of dissociated acidic groups was determined on the basis of potentiometry. Several differences between the behaviour of humic and fulvic acids were found. While whole samples of fulvic acids including the weakest functional groups were analysed, only the active dissolved humic fractions containing stronger acidic functional groups were characterized. The fractions containing higher amounts of the weakest functional groups remained insoluble. The dissociation degree of fulvic acids decreased with their increasing content, but a maximum on its concentration dependence obtained for humic acids was observed. Conclusions: Two different values of dissociation constants were determined for each sample. The first was determined on the basis of the extrapolation of infinite dilution, second was determined as their average value in the region of high concentrations in which it was constant. Obtained values characterize the functioning of dissolved humic substances from point of view of their dissociation ability. The results obtained by this approach can help to predict the acid-base behaviour of dissolved organic carbon in soil and generally in nature. The acid-base behaviour of dissolved organic carbon depends on its ratio to water. It behaves differently in soil which is dry and in soil which is wet or saturated by water.en
dc.description.abstractPro charakterizaci disociačního chování huminových a fulvinových kyselin byla využita metoda průtokové coulometrie (chronopotenciometrické titrace), která dokáže stanovit celkový obsah kyselých funkčních skupin ve výluzích huminových látek. V kombinaci s potenciometrickým měřením pH je pak možno stanovit disociační konstanty aktivních funkčních skupin huminových frakcí přecházejících do výluhu.cs
dc.relation.ispartofChemical and Biological Technologies in Agriculturecs
dc.rightsCreative Commons Attribution 4.0 Internationalcs
dc.subjectDissolved organic matteren
dc.subjectSupramolecular polyelectrolyteen
dc.subjectHumic acidsen
dc.subjectFulvic acidsen
dc.subjectDissociable acidic functional groupsen
dc.subjectrozpuštěná organická hmota
dc.subjectsupramolekulární polyelektrolyt
dc.subjecthuminové kyseliny
dc.subjectfulvinové kyseliny
dc.subjectdisociovatelné kyselé funkční skupiny
dc.titleNew possibility for characterization of dissociation behaviour of supramolecular electrolytes: results obtained for the International Humic Substances Society standard and reference samples by coulometryen
dc.title.alternativeNová možnost charakterizace disociačního chování supramolekulárních elektrolytů: výsledky získané pro standardy a referenční vzorky International Humic Substances Society pomocí coulometriecs
thesis.grantorVysoké učení technické v Brně. Fakulta chemická. Ústav fyzikální a spotřební chemiecs
sync.item.insts2021.08.12 16:55:50en
sync.item.modts2021.08.12 16:14:29en

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Creative Commons Attribution 4.0 International
Except where otherwise noted, this item's license is described as Creative Commons Attribution 4.0 International