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RECORD NUMBER: 142 OF 309

OLS Field Name OLS Field Data
Main Title Fluorescence Techniques for Metal-Humic Interactions.
Author Susetyo, W. ; Carreira, L. A. ; Azarraga, L. V. ; Grimm, D. M. ;
CORP Author Environmental Research Lab., Athens, GA. Office of Research and Development. ;Georgia Univ., Athens. Dept. of Chemistry. ;Technology Applications, Inc., Athens, GA.
Publisher c1991
Year Published 1991
Report Number EPA/600/J-91/215;
Stock Number PB92-101369
Additional Subjects Humic acids ; Fluorescence ; Titration ; Ion probes ; Europium ; Spectrum analysis ; Copper ions ; Water pollution ; Ligands ; Mathematical models ; Reprints ; Metal humic interactions
Holdings
Library Call Number Additional Info Location Last
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Status
NTIS  PB92-101369 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 02/24/1992
Collation 14p
Abstract
Two fluorescence techniques to study metal-humic interactions are presented. In the first technique, Lanthanide Ion Probe Spectroscopy (LIPS), the humic samples are titrated by Eu(+3) ions. The ratio of the intensities of two emission lines of Eu(+3), R=I(sub 592)/I(sub 616), is used to estimate the amount of bound and free species of the probe ions. The titration plot is presented as R versus the logarithm of total added Eu(+3). In the second technique, fluorescence quenching of the humic material by Cu(+2) is used to produce titration curves of intensity versus the logarithm of total added Cu(+2). The two techniques are used in conjunction with a model that treats the various ligands in humic substances as continuous distributions of binding sites in which individual ligand concentrations are normally distributed with respect to the individual stability constants for metal binding. The model includes the effects of pH, ionic strength, and competing metal ions. The parameters of the model are estimated by fitting the spectral titration data to the calculated titration plot. Some simulation and experimental data are presented and discussed. (Copyright (c) Springer-Verlag 1991.)