-17However,
if Fe? were present in this sample in the same ratio
to Pe? as that observed in other samples collected at the same
time, the activity would have been approximately 1,300,000 d/m
of Fe>>.
The ammonium citrate fraction at pH 3.5 exhibited high
levels of B
the
Y
radiation in samples 3,5 b-c-d-e (Fig. 1).
Because
spectrum contained several peaks which could not be iden-
tified a further ion exchange separation was made (Fig. 1, inset)
on this fraction according to the method of Kimura et al. (1956).
The first peak of the second elution with ammonium citrate
at pH 3.1 was sharply separated from the next peak at pH 3.3
(Fig. 1, inset).
Although the first peak had a high P
tegration rate the Y
activity was very low.
disin-
The isotope in
this peak was identified as yt since yttrium was known to be
eluted at this position and in addition the A
raciation had a
maximum energy equal to that of yt (1.54 MEV, 600 me/em* range
in aluminum).
‘The observed half life for this fraction was iden-
tical with the 58-day half life of y?,
of the sample, based on the §
The total Y
91 content
count, was 46,400 dfn,
The second peak of the second elution occurred at pH 3.3,
fractions c through r (Fig. 1, inset).
tions comprising this peak by
Y
spectrometry revealed
of the following energies (Fig. 3).
0.08 MEV (weak)
0.12
0.51
0.81
1.0
1.17
1,33
MEV
MEV
MEV
MEV
MEV
MEV
Examination of the fracY
peaks