Copper speciation by competing ligand exchange method using differential pulse anodic stripping voltammetry with ethylenediaminetetraacetic acid (EDTA) as competing ligand
| Autor: | Chuni L. Chakrabarti, Rong Wang |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
media_common.quotation_subject
Inorganic chemistry chemistry.chemical_element Fresh Water Ethylenediaminetetraacetic acid Ligands Binding Competitive Sensitivity and Specificity Biochemistry Analytical Chemistry chemistry.chemical_compound Electrochemistry Environmental Chemistry Humic acid Electrodes Edetic Acid Spectroscopy Chelating Agents media_common Ontario chemistry.chemical_classification Ligand Reproducibility of Results Copper Ion Exchange Anodic stripping voltammetry Speciation chemistry Stability constants of complexes Titration Environmental Monitoring |
| Zdroj: | Analytica Chimica Acta. 614:153-160 |
| ISSN: | 0003-2670 |
| Popis: | A technique has been developed to study chemical speciation of copper in freshwaters by competing ligand exchange (CLE) method using anodic stripping voltammetry (ASV) in the differential pulse (DP) mode with ethylenediaminetetraacetic acid (EDTA) as a competing ligand. The voltammetric behavior of Cu(II)–EDTA complex has been investigated using DPASV. When DPASV is used at an appropriate deposition potential, the inert Cu(II)–EDTA complex becomes electroactive, and is reduced directly. Furthermore, at the same deposition potential, Cu(II)–fuvic acid and Cu(II)–humic acid complexes do not contribute significantly to the analytical signal, which makes EDTA a suitable competing ligand in the determination of copper speciation using CLE–ASV. This method has been applied to freshwater samples from Rideau Canal (Ottawa, ON, Canada). The analysis of the copper titration data of these freshwater samples has indicated the presence of a very strong copper-binding ligand with a conditional stability constant of approximately 1020 and a corresponding very high concentration (above 100 nM) of the ligand. |
| Databáze: | OpenAIRE |
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