| Atomic number: | 53 |
| Atomic weight: | 126.9045 |
| Average concentration in ocean: | 460 nmol/kg |
| Residence time: | 340,000 yearrs |
Speciation
The iodate ion (IO3-) is the stable form of iodine in
seawater. However, in the euphotic zone, some of IO3-
is reduced to I- as phytoplankton reduce NO3-
to NO2-.
Distribution in ocean
The vertical profile
of IO3- is slightly depleted at the surface due to
uptake and removal, while the I- concentation has a surface maximum (data).
Residence time
The iodine residence time is from Tracers in the Sea (Broecker, W. S. and Peng,
T.-H., 1982. Eldigo Press, Palisades, NY). It was calculated from
the global average river input.
Analysis
Iodine has been determined by neutron activation analysis, electrochemical
analysis and by inductively coupled plasma mass spectrometry.