The analytical ®gures of merit and operational
performance of the FI±CL system during two months
of continual shipboard analyses demonstrate the practicability
and accuracy of this simple technique for
sub-nM Fe(IIIII) determinations. The ability of the
method to map Fe in open-ocean waters will aid in the
elucidation of Fe input mechanisms and distributions
in remote oceanic ecosystems. Further development of
the method is planned in order to differentiate the
redox forms. This will be achieved by incorporating
two sample flow lines, one for Fe(II) and the other in
which the sample is reduced in-line for Fe(IIIII).
Experiments will also partition between different
operationally de®ned Fe(IIIII) fractions