Naslov
Composite ferric oxyhydroxide-containing phases formed in neutral aqueous solutions of tryptophan and indole-3-acetic-acid

Autori
Kamnev, Alexander ; Kuzmann, Erno ; Perfiliev, Yuri ; Vertes, Attila ; Ristić, Mira ; Popović, Stanko

Izvornik
Journal of Radioanalytical & Nuclear Chemistry (0236-5731) 246 (2000), 1; 123-129

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Mossbauer spectroscopy. Anthranilic acid. Iron oxides. Ferrihydrite. FeOOH particles. Beta-FeOOH

Sažetak
Mossbauer, FTIR and XRD analyses showed that in aqueous medium in air in the presence of L-tryptophan(Trp) or indole-3-acetic acid (IAA) the ambient-temperature ageing of the precipitates formed from ferrous sulphate at pH similar to 7 gave composite phases with varying proportions of gamma-FeOOH (a dominating crystalline phase), alpha-FeOOH (both fine-grained, showing superparamagnetic behaviour at 298 K, and relatively better crystallized) and amorphous ferric hydroxide. The experimental data suggested a competition for adsorption sites at the oxyhydroxide surface in the suspension during phase transformations, as well as the transformation of gamma-FeOOH (and/or amorphous ferric hydroxide) to alpha-FeOOH via the dissolution-reprecipitation mechanism. The formation of certain ferric oxyhydroxide phases in the presence of Trp and IAA-released e.g., in the course of bacterial and plant metabolism - can contribute to the regulation of soil mineral composition.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA