Determination of chemical species of iodine in algae Ⅰ

The chemical species of iodine in 7 marine algae Cadium fragile, Ulrxi pertusa, Monostroma mtidum, Gracilasia confervoides, Sargassum miyabei yendo, IJictyopteris divaricala and Laminara japonica were studied using neutron activation analysis combined with chemical separation. The contents of total iodine, water soluble iodine, organic iodine. I^- and IO₃^- in 7 algae were determined. The results indicate that the chemical species and contents of iodine in various algae are remarkably different. The highest iodine content of 734×10⁶ Cwet basis) was found in Laminara japonica, and with 99.2% of total iodine being water soluble iodine. The iodine contents in other 6 algae are lower, and the soluble iodine makes up 16%～41% of the total. In the aqueous leachate, iodine is mainly I^-,which amounts to 61%～93% of total water soluble iodine, the percentages of organic iodine make up 5.5%～37.4%. The content of IO₃^- is the lowest, which is 1.4%～4.5% of total iodine.,These suggest that the mechanism of iodine enrichment is possibly different for various algae, and its bioavailabiGty varies as well.