Gamma spectra were made from plankton samples aboard
the Collett by means of a single-channel fifty-position
spectrometer to determine the presence of gamma-emitting
radioisotopes other than the expected fission products.
Selected samples containing mixtures of gamma emitters were
wet ashed, dissolved in acid solution and passed through a
cation exchange column for the separation of the radionuclides.
The radioisotopes were identified by beta and gamma
energies and by the elution fractions in which they were
found.
Confirmation of the presence of wi85 was obtained by
chemical precipitation techniques,
by beta and gamma energies
and by comparison of sample radionuclide separations with control experiments utilizing spikes of wi85 |
Maximum beta
energy was determined by mass absorption techniques.
The precipitation method of analysis (Kleinberg, 1954)
for wi8s5 consisted of two precipitations of tungstic acid,
each followed by the dissolving of the precipitate in concentrated NH,OH.
The solution was then scavenged with Fe(OH)3,
and with molybdenum and bismuth sulfides in the presence of
tartaric acid.
Niobium was removed by extraction with chloro-
form and cupferron and the tungsten reprecipitated as tungstic
acid.
wiSs
The gamma spectrum of the final precipitate showed only
free from other gamma emitters.