FLUORESCENCE QUENCHING OF ANTHROPOGENIC FULVIC-ACIDS BY CU(II), FE(III) AND UO22+

Citation
Jcge. Dasilva et al., FLUORESCENCE QUENCHING OF ANTHROPOGENIC FULVIC-ACIDS BY CU(II), FE(III) AND UO22+, Talanta, 45(6), 1998, pp. 1155-1165
Citations number
43
Categorie Soggetti
Chemistry Analytical
Journal title
Talanta
ISSN journal
00399140 → ACNP
Volume
45
Issue
6
Year of publication
1998
Pages
1155 - 1165
Database
ISI
SICI code
0039-9140(1998)45:6<1155:FQOAFB>2.0.ZU;2-M
Abstract
The quenching of the fluorescence of three anthropogenic fulvic acids (FA) provoked by Cu(II) (pH 6.0), Fe(III) (pH 4.0) and UO22+ (pH 3.5), was analyzed by a non-linear method and by Stern-Volmer plots. The FA samples were extracted from composted sewage sludges (csFA), composte d municipal wastes (mwFA) and composted livestock wastes (IsFA). Synch ronous-scan fluorescence (SyF) spectra were collected as a function of metal ion concentration. Spectral data were treated by a self-modelin g mixture analysis method (SIMPLISMA) to detect the SyF spectral band with the strongest quenching and to calculate the corresponding quench ing profile. The analysis of these profiles by a non-linear method all owed the estimation of conditional stability constants (K) and of the percentage of non-complexing fluorophores. The same quantitative infor mation was obtained by the modified Stern-Volmer equation taking into account the existence of fluorophores that do nor participate in the c omplexation. Good agreement was found between the results of the two p rocedures. The log K calculated by the non-linear method were (standar d deviation in parenthesis): csFA, Cu(II), 4.22 (5); Fe(III), 5.0 (1); UO22+, 5.2 (2); mwFA, Cu(II), 4.21 (3); Fe(III), 5.6 (2); UO22+, 4.7 (3); 1sFA, Cu(II), 4.51 (8); Fe(III), 5.5 (2); UO22+, 3.6 (2). (C) 199 8 Elsevier Science B.V.