Effect of pH on complexation of Fe(III) with fulvic acids

• Tipo: Artigo em Revista Científica Internacional
• Data: 1998

Autores

da Silva, JCG (Autor) FCUP; Machado, AASC (Autor) Outra; Oliveira, CJS (Autor) Outra

Revista

Título: Environmental Toxicology and Chemistry

Vol. 17

Páginas: 1268-1273

ISSN: 0730-7268

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 12 Citações

Scopus - 16 Citações

Classificação Científica

FOS: Ciências médicas e da saúde > Medicina básica

Outras Informações

ID Authenticus: P-001-7HN

DOI: 10.1897/1551-5028(1998)017<1268:eopoco>2.3.co;2

Abstract (EN): The interaction of Fe(III) with two samples of fulvic acids (FAs) extracted from a pinewood soil (FA2: horizon 0-10 cm; FA3: horizon 10-25 cm) was monitored by synchronous fluorescence (SyF) spectroscopy at four pH values (3, 4, 5, and 6). Spectral data were preprocessed by SIMPLISMA, a self-modeling curve-resolution method, and from the calculated quenching profiles, equilibrium parameters for the interaction of Fe(III) and FAs were obtained (conditional stability constants [K(c)s] and ligand site concentrations). The calculated log K(c)s were (I = 0.1 M KNO3; standard deviation in parentheses) FA2, pH = 3, 4.9 (2) pH = 4, 4.7 (2), pH = 5, 5.1 (4), and pH = 6, 5.1 (1); FA3, pH = 3, 5.48 (1); pH = 4, 4.96 (7), pH = 5, 4.89 (1), and pH = 6, 5.1 (2), where I is the ionic strength. These results show that FA forms quite stable soluble complexes with Fe(III) in the acid pll range.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6