Electron paramagnetic resonance characterization of a humic acid-type polymer model

Humic acid-type polymer models have been shown to be similar to natural humic acids (HA) in terms of chemical properties. Due to the complexity of humic substances (HS), this humic acid-type polymer models, in which the ligand sites are better defined, can be used in the study of metals and for other applications. In this study, a polymer with characteristics analogous to those of humic acids isolated from soil surface cultivated using a no-tillage system for nine years, was obtained by means of synthesis reactions, through oxidative polymerization in an alkaline medium using para-benzoquinone as precursor. An EPR spectroscopy study was made of natural humic acids (HA) and synthetic humic acids (SHA). A semiquinone-type free radical signal was detected in the SHA. The spectra showed similar signals for HA from soil and synthetic HA complexed with Fe3+, Cu2+ and Mn2+ ions.

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Bibliographic Details
Main Authors: Barriquello,Marcilene F., Saab,Sergio da Costa, Consolin Filho,Nelson, Martin-Neto,Ladislau
Format: Digital revista
Language:English
Published: Sociedade Brasileira de Química 2010
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532010001200018
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