Humic Acid Binding of Trivalent Tl and Cr Studied by Synchronous and Time-Resolved Fluorescence

Autor:	Giovanni Bidoglio, Domenico Ferrari, Elena Selli, Fabrizio Sena, Gabriele Tamborini
Rok vydání:	1997
Předmět:	chemistry.chemical_classification Quenching (fluorescence) Ligand Analytical chemistry Fluorescence spectrometry General Chemistry Fluorescence Ion Metal chemistry visual_art visual_art.visual_art_medium Environmental Chemistry Humic acid Time-resolved spectroscopy
Zdroj:	Environmental Science & Technology. 31:3536-3543
ISSN:	1520-5851 0013-936X
DOI:	10.1021/es970294x
Popis:	The complexation of Tl(III) and Cr(III) with groundwater humic acids (HA) was investigated at pH 4.5 and pH 5.5 using different fluorescence methods. These comprised both quenching measurements of the continuous and synchronous fluorescence of the HA ligand and an ion competition method based on the time-resolved laser-induced fluorescence of HA-bound Eu(III). Modeling of the experimental data using an electrostatic discrete site approach (Model V), yielded comparable values of intrinsic binding constants for each of the studied metal, independently of sample conditions (pH, metal:ligand ratio) and fluorescence method used. The results confirmed the validity of fluorescence techniques in the analysis of low concentration metal ion−HA interac tions and indicated that, beside the aquo ion and the first hydroxo complex, other species may also bind to humic acids.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::e715ed4f97d5f715768d97c88e90300f https://doi.org/10.1021/es970294x Zobrazit plný text záznamu