FACTOR-ANALYSIS OF MOLECULAR FLUORESCENCE DATA OF MARINE AND SOIL FULVIC-ACIDS

• Tipo: Artigo em Revista Científica Internacional
• Data: 1993

Autores

machado, aasc (Autor) Outra; dasilva, jcge (Autor) FCUP

Revista

Título: Chemometrics and Intelligent Laboratory Systems

Vol. 19

Páginas: 155-167

ISSN: 0169-7439

Editora: Elsevier

Indexação

ISI Web of Knowledge - 39 Citações

Scopus - 39 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia electrotécnica, electrónica e informática

Outras Informações

ID Authenticus: P-001-MZR

DOI: 10.1016/0169-7439(93)80099-4

Abstract (EN): The variations observed in synchronous fluorescence spectra of fulvic acids have been characterised by principal component analysis and evolving factor analysis. Fulvic acids from coastal marine waters (mfua) were examined as a function of pH (between 2 and 7) and Cu(II) concentration. Fulvic acids from soil (sfua) were examined as a function of pH (between 2 and 7) and Cu(II), Co(II) and Ni(II) concentration. Fluorescence properties of sfua are characterised by a constant plus three varying components (defined by three individual spectra), corresponding to three acid-base equilibria with pK(a) values of 3.0, 4.6 and 6.4. For mfua, a constant plus two varying components (defined by three individual spectra) were detected, corresponding to two acid-base equilibria with pK(a) values of 3.1 and 5.3. The influence of the ions on the acid-base equilibrium diagrams is also quantified.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 13