Thesis for the Degree of Doctor of Philosophy - DTU Orbit
Thesis for the Degree of Doctor of Philosophy - DTU Orbit
Thesis for the Degree of Doctor of Philosophy - DTU Orbit
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Analysis <strong>of</strong> 129 I and 127 I in archived Fucus Vesiculosus samples from Denmark<br />
Violeta Hansen 1 & Per Roos 1<br />
1 Risø National Laboratory <strong>for</strong> Sustainable Energy NUK-202, Technical University <strong>of</strong> Denmark,<br />
DK-4000 Roskilde, Denmark<br />
Abstract<br />
Marine algae play an important role in <strong>the</strong> global cycle <strong>of</strong> iodine in <strong>the</strong> environment in <strong>the</strong><br />
sense that <strong>the</strong>y accumulate seawater iodine at high concentration levels and have <strong>the</strong> ability to<br />
trans<strong>for</strong>m iodine into volatile <strong>for</strong>ms. In this study spatial and temporal trends in 129 I and 127 I<br />
concentrations in archived Fucus Vesiculosus samples collected from Rømø in <strong>the</strong> North Sea,<br />
Klint in <strong>the</strong> Kattegat, and Bornholm in <strong>the</strong> Baltic Sea have been evaluated using AMS and ICP-<br />
MS respectively. Concentrations <strong>of</strong> 129 I in Fucus from Rømø, North Sea proved to be at least<br />
one order <strong>of</strong> magnitude higher than concentration in Fucus from Bornholm, Baltic Sea. The 129 I<br />
content <strong>of</strong> Fucus increased significantly between 1986 and 2010. Yields ratios <strong>of</strong> 129 I/ 127 I<br />
(seaweed) relative 129 I/ 127 I (seawater) were found to be 0.5 <strong>for</strong> North Sea (2005), 0.7 (2006) <strong>for</strong><br />
Sou<strong>the</strong>rn Kattegat and 0.97 (2007) <strong>for</strong> Bornholm indicating that Fucus Vesiculosus can be used<br />
as bio-indicator organisms <strong>for</strong> iodine-129 in marine environment. Fur<strong>the</strong>rmore our data reveal<br />
that <strong>the</strong> iodide is more efficient to accumulate than iodate in Fucus.<br />
Key words: 129 I, 127 I, Fucus Vesiculosus, alkaline digestion, AMS, ICP-MS, Baltic Sea, North<br />
Sea.<br />
1. Introduction<br />
1