Toth $259 and TSO are measured dy beta countins,

-

ba tan

sollectad on 1-1/8 inch paper or glass filters,

The preeit

The filters

:

oe

aay
sates
ra

are no wmted

on Tracerlab brass ringeandedise holders, and covaread with d O01 plio=
a

film.

This shows negligible absorption and prevents contami nation and

loss of samples during handling.

Counting is performed with 1 inch diameter Anton flat haloge =fillead GM.
tubes moumted in simple lead castles, The background counti - rate of
these counters is maintained at six counts per minute and th efficiencies

at about 15=20%,

Higher efficiencies could be obtained but

re not cone

sidered to be necessary, The counters are standardized wit potassium
carbonate mounted on the same holders, A 0,200 gram quantity of potassium
carbonate which should show 163 d/min (from the K+ content) rives suitable
counting rates for standardization,

The counting times were of the order of 50 minutas for backer und and samples
ard all rasults are raported with the standard deviasions cal ulated for
the error of the sample when the background error is taken info account.
Figures 1 to 3 show the es values for background conting rate of 4, 6 and
8 o/min and counting times of 30, 60 and 120 minutes where th sample and

backeround counting times are equal,

(In ow normal work, 2s

used, but in this report, the ls deviations are reported to c

ceneral usage).

lues ars
orm with

y90 samples are followed for decay for identification purpose stand residual
aotivity, if any, is subtracted from the total Y, YO disint eafration rates
are determined by extrapolation back to the time of saparatio nifrom the
Sr90 parent but are not corrected for self-absorption ty the sample, Further
identification is possible by absorption measurements when th © fample is
sufficiently aotive.
Some samples were analyzed for normal strontium in order to s tufy the up=

Saks by plants and animals.

Tho nitrate procedure is used for

fhe separation

Strontium
of strontium from massive amounts of caloiium and other elsoments
carrior carmot, of course, be used in this procedure but it hasbeen found
possible to obtain good recoveries with a barium carrier, Th e wesulting
precipitate is dissolved and analyzed for strontium with the flame photometer,

Radium analyses were run on many of the samples. Ali samples es
were analyzed by the standard method of co~precipitation of the
with barium sulphate and alpha counting.
This treatment is n ot

Lonization chambers.

ewer methods of analyses are in the development stage tut have

used on any of the samples reported in this paper as it was felt |
standardization was vary important where many results are to be c
with one another. As noted earlier, the complete anal:tical proc
are given in Appendix A,

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