A new approach to metal complexation studies of humic substances by lanthanide ion probe spectroscopy

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6619369

Dobbs, J C

Humic materials are an important source of binding sites for metals in the environment. This study has included the development of a sensitive spectroscopic probe which provided the means to selectively probe the metal binding sites of humic substances. This approach was based on the unique luminescent features characteristic of the trivalent lanthanide ions. Europium (III) metal ion has been selected as the initial probe metal. The fluorescence spectra of the probe metal ion were sensitive to ligation of the metal ion. The changes in the fluorescence spectral were monitored throughout the metal titration process. The analysis of these data provided the means to calculate quantitatively the concentrations of the bound and free metal ions as a function of the total metal added during the titration process. This study has also included the implementation of several continuous multigand complexation models to describe the complexation of the Eu(III) probe metal ion with the selected Suwannee River fluvic acid material. Eu(III) binding and characterization of humic substances were evaluated in terms of several characteristic modeling parameters in accordance with the Gaussian distribution model. The pH dependence of metal-humic complexation has also been described. Once the binding characteristics of the probe metal ion were established, the lanthanide ion probe techniques was used in conjunction with a multi-metal pH dependent continuous multiligand model to measure the binding constants of other non-luminescence metals and their humic complexes. Because of its abundance and environmental interest, an aluminum-humic complexation reaction was chosen as the initial model reaction to illustrate this interesting and potentially very useful analytical technique.

• Research Organization: Georgia Univ., Athens, GA (USA)
• OSTI ID: 6619369
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
FLUORESCENCE SPECTROSCOPY
PERFORMANCE TESTING
METALS
CHEMICAL REACTIONS
ORGANIC MATTER
ALUMINIUM
COMPLEXES
ENVIRONMENTAL MATERIALS
EUROPIUM
FULVIC ACIDS
HUMIC ACIDS
MATHEMATICAL MODELS
MEASURING METHODS
PH VALUE
PROBES
SPECTRA
TITRATION
ELEMENTS
EMISSION SPECTROSCOPY
MATERIALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
RARE EARTHS
SPECTROSCOPY
TESTING
400201* - Chemical & Physicochemical Properties
540220 - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)