Repozytorium
Wyszukaj
Kolekcje
Inne
Influence of metal ions binding on free radical concentration in humic acids. A quantitative electron paramagnetic resonance study.
Autorzy
Rok wydania
2002
Czasopismo
Numer woluminu
33
Strony
265-268
DOI
10.1016/S0146-6380(01)00158-9
Kolekcja
Język
Angielski
Typ publikacji
Artykuł
The influence of metal ions, e.g. Co(II), Cu(II), Mn(II), Ni(II), Fe(II), on free radical concentration in humic acids isolated from soil, peat and compost was investigated by electron paramagnetic resonance (EPR). The results show that metal ions with unfilled d-shell exhibit antiferromagnetic interactions with semiquinone radicals. Moreover, coordinated metals shift the quinone–semiquinone–hydroquinone equilibrium in the macromolecular matrix of humic acids. A strong decrease of semiquinone radical concentration in humic acid–metal complexes is observed. This effect is caused by interactions of metal ions with oxygen-containing stable radicals occurring in the aromatic systems of humic acids. Furthermore, the effect of metal coordination on free radical concentration in humic acids–metal complexes depends on the humic acid origin. FTIR spectroscopy was also used as an additional tool for studies of the metal ions interactions with carboxylic groups.
Adres publiczny
Podobne publikacje
Influence of metal binding on free radical concentration in humic acids isolated from various sources - a quantitative EPR study.
Jerzykiewicz Maria, Czechowski Franciszek, Jezierski Adam, Drozd Jerzy
Influence of ammona and nitrogen dioxide on free radicals in humic acids derived from compost, soil, peat and brown coal. An electron paramagnetic resonance (EPR) study.
Jerzykiewicz Maria, Czechowski Franciszek, Jezierski Adam, Drozd Jerzy