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Radioassays were made of algae collected at Parry and
Bogombogo Islands during March, April,
and May,
1954.
The
|
results of these studies are given in Table I.
It was thought that the radioactivity in the samples of
Asparagopsis collected in early March might be due to a short
half life isotope resulting from the test of March 1,
Bikini.
1954 at
In order to verify this assumption series of counts for
determining radioactive half life were initiated at the Eniwetok
laboratory.
Duplicate samples were sent to the home laboratory
at the University of Washington for more complete analyses. The
results of tests conducted on samples collected at Eniwetok and
Rongelap Atolls from March through June are given in Table II.
Plots of the radioactive decay of three samples of Asparagopsis are shown in Figure l.
.
DISCUSSION
The results of the half
analyses
®
*
life
studies and radiochemical
.
indicate that at least 90 per cent of the radioactivity
The radiochemical method for determination of 3 was adapted
from Glendenin etal.
(2) and is as follows:
The dried algae
were heated several minutes with Nacl0O and 0.1 N NaOH containing
iodine carrier (added as Kl), filtered, and discarded.
The iodine
in the solution was reduced with hydroxylamine hydrochloride, ex-
tracted into CCl,,
and re-extracted into water containing a little
bisulfite.
The aqueous solution was acidified and treated with
sodium nitrate,
The extraction into carbon tetrachloride and into
water was repeated.
The iodine was precipitated from the result-
ing
solution as silver iodide and counted in an internal gas-flow
counter,
a dkeg.
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