19a.
;
:
as
cv" 7 Amalvsis of Marsnualil
island
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:
Tavironmencal Samp.i2s
Amalyvtical and Quality Assurance Procedures
Wwe
F.P. 3rauer and J.2. Naidu’
INTRODUCTION
Neutron activation analysis is used for trace level measurements of iodin
in Dbiological and environmental materials.
(
te?
tr
y
ok
+:
1
oe
I) and the long-lived (1.6 x 10°
7
Both mono-isotopic natural iodine
oes
*
129
vears) fission-oroduced
I occur
.
in sam-
ole materials and can be analyzed by neutron activation analysis (1,2,3).
Since
:
- l27,.
the environmental sources of
I and
.
in
2
ent cmecical forms and ecological sachways, measuremenc of the
"4
rh
tt
.
Ai
129.
. ae
Ls
“°I are diiferenc, whien Mav resulfe
.
.
-,
Lsotopic ratio
.
is essential
.
.
-
in studies of
.
. 129
the radiloecology of
9
14
129,
227,
T (2,4).
™
Jaric
aricus
(5,6,7,3).
and fr
ers:
contrisute
processes
Nacurally occurring
129
¢o
.
the
la
rel2ase
=
oz
129,
.
r
£9
4
tae
:
environoent
I results from sponcaneous fission of uranium
sosmic-ray produced spallation reactions with atmospheric xenon.
made releases of
9
129
(tfan-
.
.
I have resulted from nuclear weapon tests and irom auclear
installation operations.
ANALYSIS METHOD
.
.
Decermination of
the
129
I
.
coneeneration and
the
129, ,127
L/
I ratio in moset en-
vironmental and biological materials requires initial separation of the.
Once separated,
the iodine is irradiated with neutrons in a
purified
further to reduce
levels of interfering radionucii<es,
and then determined by gamma-ray spectrometric measurements.
*Bactelle Pacific Northwest Laboratories, Richland Washington
**Brookhaven National Laboratory, Upton, New York
—S ee
nuclear reactor,
TTS
——
contained icdine.