3
4
-
mtercering reactions
s/f
t
include:
9
[25
2 yr 126,
2°
3.4
Le
+25,
(4)
4
4
Interterence from reaction (4) is minimized by use of small activity
:
- 125
125
.
,
;
.
-avels of
Io so fhac
I production by raaction (2) predominates.
(3)
;
Reacrion
limits the improvement in sensitivity that can be obtained by increasing the
exposure time and neutron flux.
Neutron exposure conditions ara selected on the
Sasis of axpected stable iodine content of ziven sample types in order to limic
the correction required due to reaction (5) to less than 10%.
Following irradiation the quartz ampoules are cleaned, frozen with liquid
aitrogen and crushed into a reaction vesse! containing a dilute H SO, solucion
2
2f Lodine and Sromine carriers and Wa,5,9; (sodium pvresulfire).
removed by sparging with nitrogen.
Excess $0, is
The bromide and iodide ions are then
oxidized to bremine and iodate by the addition of Kind and the bromine
distilled from the solution.
reduced to iodide wich Na,$,0.
27255
th
dine
The iodate remaining in the reaction vessel is
and then oxidized to iodine with HO
is distilied from the reaction vessel into a Ya,5,05 solution.
a
=
The ioThe iodine
vaction is further surified by oxidation with A951 extraction into cel), and
9ack 2xtracCion with Na,5,05 solution.
The extractions are repeated as neces-