THE RADIOCHEMISTRY OF PLUTONIUM - Sciencemadness.org

Autoradiography
Reagents and equipment.
Developer, Kodak D- 19.
Fixer, Kodak F-5
Nuclear-track alpha (NTA) plates – l-in. X 3-in. glass slide with 25-P
emulsion.
NTA exposure camera.
Microprojector – arc illuminated, with 21X objective and 20X ocular.
Chromic acid solution – Dissolve 0.2 g Cr03 in 1 liter distilled water.
Plate preparation
1. Fill staining dish two-thirds full of Cr03 solution.
2. In darkroom with red safe light, remove slides from box and place
in staining- dish rack. Lmmerse rack and slides in C r03 solution
for 4 min. Let drain 5 sec. Turn off red safe light and wash in
rinse tank 20 min.
3. Remove rack from wash tank and let slides dry.
Autoradiographic procedure
1.
2.
3.
4.
5.
Calculation
from standard curve.
References
In darkroom with Series AO light filter, load NTA plate in slide
depression of camera. Place disk positioner over NTA plates,
and drop disks face- down into holes of positioner.
Fit top securely on camera, and place camera in dark box. Expose
for 1 week.
After exposwre, develop NTA plates 10 min in D-19 developer at
68”F. Rinse in distilled water and fix 20 min in F-5 fixer.
Wash plates for 1 hr and let dry.
Count the a tracks with the microprojector. Each projection covers
an area of O. 1409 mmz, which is called one field. The total area of
the exposed h’TA plate is 38.82 mm2 or 277 fields. Tracks are
coumted on a predetermined number of fields on each plate. Tracks
found are compared with a standard curve prepared from urine
spiked with known amounts of Pu.
Since 1 liter urine sample was used, dpm Pu/liter urine = dpm
S. LM. Sanders. Determination of Plutonium in Urine, DP- 146, March 1956.
L. C. Schwendiman and J. W. Healy, “Nuclear- Track Technique for Low- Level
Plutonium in Urine, ” Nucleonics @ 78 (1958).
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