The distribution of dissolved thallium in the different water masses of the western sector of the Ross Sea (Antarctica) during the austral summer

Vertical profiles for total dissolved thallium were obtained at five sites in the western sector of the Ross Sea (Southern Ocean), Antarctica. Thallium is estimated to have a natural mean seawater concentration between 50 and 65 pmol L−1with higher values in theNorth Pacific (65±5 pmol L−1) and lowe...

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Bibliographic Details
Published in:Microchemical Journal
Main Authors: C. Turetta, BARBANTE, Carlo, CAPODAGLIO, Gabriele, GAMBARO, Andrea, CESCON, Paolo
Other Authors: C., Turetta, Barbante, Carlo, Capodaglio, Gabriele, Gambaro, Andrea, Cescon, Paolo
Format: Article in Journal/Newspaper
Language:English
Published: 2010
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Online Access:http://hdl.handle.net/10278/31343
https://doi.org/10.1016/j.microc.2009.07.014
Description
Summary:Vertical profiles for total dissolved thallium were obtained at five sites in the western sector of the Ross Sea (Southern Ocean), Antarctica. Thallium is estimated to have a natural mean seawater concentration between 50 and 65 pmol L−1with higher values in theNorth Pacific (65±5 pmol L−1) and lower inthe Bay of Biscay and Irish Sea (49±3 pmol L−1). Our samples show a concentration varying from22 to 55 pmol L−1 with amean value of 46 pmol L−1, depending on depth, dissolved oxygen, salinity and local topographic characteristics. The analyses were performed using an ICP-SFMS that has enabled us to obtain reliable Tl concentrationmeasurements with a relative standard deviation of better than 2.5% and a detection limit, calculated as three times the standard deviation of the “blank signal” of 0.69pmol L−1 (1.60 pmol L−1, obtained analysing four blank solutions (n=5) prepared with the same water and acid used for the dilution/acidification steps). Thallium appears to have a nearly conservative distribution in seawater as highlighted also from the comparison with the profiles of two seawater conservative elements:molybdenumand uranium;however it also highlights the presence of a reactive component of thallium, which is more influenced by the presence of particulate matter, oxygen content and fluorescence.