Iodine, ruthenium and technetium

Iodine - The importance of oxidation-state speciation of radioiodine was recognised at a very early stage because of its ability to accumulate in and cause damage to the human thyroid gland. Iodine-131 (t1/2 = 8.04 days) would therefore be 

In environmental waters, the most important oxidation states are iodide ( — 1) and iodate ( + 5). Most published methods for the analysis of radioiodine aim only to convert all species to one chemical form in order to determine a total concentration value for the particular nuclide of interest. However, some specialist methods designed for the analysis of the stable element such as that recently described by Woittiez et al. (1991) for the determination of iodide, iodate, total inorganic iodine and charcoal-absorbable (organic) iodine in seawater could presumably be adapted to provide information about the speciation of radioiodine as well. More difficult to adapt would be techniques such as polarography which have been useful in the measurement of the iodide/iodate system (e.g. Liss et al., 1973). 

Technetium - In oxic seawater 99Tc appears to be present almost exclusively as the pertechnetate ion (TcOij ) (Beasley and Lorz, 1986). This highly soluble and 

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