Effect of the pH on the complexation of Cu(II), Ni(II) and Fe(III) ions by a vine leaf litter extract by fluorescence quenching

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

Autores

da silva, jcge (Autor) FCUP; herrero, ai (Autor) Outra; machado, aasc (Autor) Outra; barrado, e (Autor) Outra

Revista

Título: Mikrochimica Acta

Vol. 130

Páginas: 63-69

ISSN: 0026-3672

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 3 Citações

Scopus - 4 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-001-9GJ

DOI: 10.1007/bf01254592

Abstract (EN): An extract of dead vine leaves (vitis viniferal) (VLE) was obtained by the extraction procedure for fulvic acids and its interaction (at a concentration of 25 mg/L in 0.1 M KNO3) with the Cu(II), Ni(II) and Fe(III) ions was studied in the pH range between 3 and 6. This interaction was monitored by synchronous molecular fluorescence, since bands due to the fluorescent ligands undergo quenching upon complex formation. After the chemometric isolation of the quenching profiles from the raw spectra by a self-modeling mixture analysis, SIMPLISMA, they were analyzed by two methods: (i) graphical procedures based on the Stem-Volmer model; and (ii) a non-linear least-squares procedure. For the Cu(II) and Ni(II) ions, the treatment by these two methods provided similar values both for the logarithm of the conditional stability constants (log Kc) and the percentage of fluorescent structures that do not participate in the complexation. The log Kc were (standard deviations in parenthesis): Cu(II) ion, 2.4(3), 3.37(3), 4.4(1) and 4.92(9), respectively, for pH = 3, 4, 5 and 6; Ni(II)ion, 2.9(1), 3.3(2), and 4.09(3), respectively, for pH = 4, 5 and 6. For Fe(III) an interaction with VLE was observed, but no values for Kc could be obtained.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7