Dissociation ability of humic acids: Spectroscopic determination of pKa and comparison with multi-step mechanism.
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26310%2F14%3APU108195" target="_blank" >RIV/00216305:26310/14:PU108195 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1016/j.reactfunctpolym.2014.02.005" target="_blank" >http://dx.doi.org/10.1016/j.reactfunctpolym.2014.02.005</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.reactfunctpolym.2014.02.005" target="_blank" >10.1016/j.reactfunctpolym.2014.02.005</a>
Alternative languages
Result language
angličtina
Original language name
Dissociation ability of humic acids: Spectroscopic determination of pKa and comparison with multi-step mechanism.
Original language description
Humic acids are operationally defined as the fraction of humic substances which is not soluble under acidic conditions. This, does not mean, however, that their solid particles easily dissolve in water. Experimental results suggest that the dissolving of solid humic acids in an aqueous environment is more complex than the conventional solubility behaviour of sparingly soluble solids. The multi-step mechanism of their interaction with water includes partial equilibrium dissolution as well as direct equilibrium dissociation from the solid state. In this work, the pKa value of the dissolved humic acid fraction was determined on the basis of changes in the shape and intensity of their UV/VIS spectra measured in media with various values of pH. The shape of the spectra depends on the pH value, because acidic and alkaline media, in which these compounds are dissolved, shift their dissociation equilibrium towards non-dissociated molecules or to completely dissociated species. The aim of this work was to characterize the dissociation behaviour of selected humic samples by means of dissociation constants using this method. It was shown that the obtained values of pKa characterize the real dissociation behaviour of humic acids in an aqueous environment and can be used as the mean or effective value of pKa corresponding with the multi-step mechanism of dissociation of humic acids.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2014
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
REACTIVE & FUNCTIONAL POLYMERS
ISSN
1381-5148
e-ISSN
1873-166X
Volume of the periodical
78
Issue of the periodical within the volume
1
Country of publishing house
NL - THE KINGDOM OF THE NETHERLANDS
Number of pages
6
Pages from-to
1-6
UT code for WoS article
000335274400001
EID of the result in the Scopus database
2-s2.0-84896287981