In-Situ Estuarine Measurements of Dissolved Cd, Cu and Pb Using a Voltammetric In-Situ Profiling (VIP) System
Abstract
In recent years there has been a trend from discrete seawater sample collection with laboratory based trace metal analysis to underway continuous sampling with automated ship-board analysis. This approach has resulted in minimization of contamination risk and enhanced spatial and temporal data resolution. The latest development in marine dissolved trace metal measurements involves the use of in-situ instrumentation that allows unattended determinations of Cd, Cu and Pb up to 500 m depths. The voltammetric in-situ profiling (VIP) system (Tercier et al., 1998, 2000) is based on anodic stripping voltammetry (ASV) and uses an agarose coated iridium based microarray as working electrode. This approach allows the measurement in seawater of subnanomolar concentrations of labile Cd, Cu and Pb species, with a size < ca. 2 nm. This presentation demonstrates results of analytical laboratory trials, in which the VIP system was subjected to simulated estuarine conditions. Also presented are the results of in-situ deployments of the VIP system showing dissolved VIP labile trace metal concentrations over a tidal cycle period in the Tamar and Fal Estuaries, England, and showing time series measurements of these metals in a Fjord in Sweden. Additional discrete total dissolved measurements indicate that an important fraction of Cu is organically complexed in these waters, in contrast with Pb. The research indicates that autonomous in-situ trace metal measurements in estuarine waters provides high resolution data which allow thorough a interpretation of biogeochemical processes in these systems. Tercier, M.L.; Buffle, J.; Graziottin, F., Electroanalysis, 1998, 10, 355-63. Tercier, M.L.; Pei J.; Buffle J., Electroanalysis, 2000, 12, 27-34.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFMOS22B0271A
- Keywords:
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- 4807 Chemical speciation and complexation;
- 4857 Pollution;
- 4894 Instruments and techniques