Speciation of Lead and Cadmium in Antarctic Seawater: Comparison with Areas Subject to Different Anthropic Influence
✍ Scribed by G. Scarponi; G. Capodaglio; G. Toscano; C. Barbante; P. Cescon
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 657 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0026-265X
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✦ Synopsis
The Antarctic surface seawater of Terra Nova Bay (Ross Sea) was investigated by anodic stripping voltammetry (ASV) to study the distribution and complexation of lead and cadmium in an extremely remote region. Samples were analyzed to determine the total metal content (after acid digestion), the metal distribution between free fraction (or ASV labile, mainly ionic and inorganically complexed metal) and bound fraction (organically complexed metal), the content of ligands complexing metal, and the related conditional stability constants. Metal complexation was studied separately by titrating the sample with each of the metals and detecting the labile fraction by differential pulse anodic stripping voltammetry. Voltammetric titration data were processed according to the van den Berg-Ruzic procedure to determine metal complexation parameters. Results for lead and cadmium revealed the presence of one class of ligands. To evaluate the possible anthropic influence in metal content and speciation in seawater, Antarctic results were compared to data obtained from different geographical areas, i.e., the Pacific Ocean, the Atlantic Ocean, and the Mediterranean Sea (Adriatic Sea). The more significant findings include the generally high proportion of bound fractions of metals ( (70-80 %) in the Adriatic Sea compared to about (50 %) in Oceanic and Antarctic waters) and a general agreement between values of conditional stability constants observed in different areas, leading to the hypothesis that the ligands are of natural origin. 1995 Academic Press, Inc.