STUDY OF AQUEOUS ACIDIC PROPERTIES OF FULVIC-ACIDS BY EVOLVING FACTOR-ANALYSIS OF PH + FT-IR TITRATION DATA

• Tipo: Artigo em Revista Científica Internacional
• Data: 1992

Autores

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

Revista

Título: Chemometrics and Intelligent Laboratory Systems

Vol. 17

Páginas: 249-258

ISSN: 0169-7439

Editora: Elsevier

Indexação

ISI Web of Knowledge - 13 Citações

Scopus - 13 Citações

Outras Informações

ID Authenticus: P-001-P1J

DOI: 10.1016/0169-7439(92)90052-h

Abstract (EN): A procedure for the estimation of the number and values of acidity constants from variations observed in aqueous Fourier transform infrared spectra of compounds containing carboxylic groups, including fulvic acids, with increasing pH, by using principal component analysis and evolving factor analysis, has been studied. The validation of the procedure was made by treating simulated data without and with random noise and data obtained in experiments with simple carboxylic compounds (acetic, shikimic, maleic, malonic and succinic acids) and binary mixtures of these compounds. The results for fulvic acids show two different types of carboxylic groups with pK(a) values of 2.8 and 4.6.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10