1
CRER-1068
INTRODUCTION
Natural strontium and barium are invariably present in
plant and animal tissue and in surface waters, but the concentrations of these elements are several orders of magnitude lower than
those of calcium and magnesium.
Nevertheless, the amounts are
sufficiently high to affect the chemical yield in the estimation
of strontium-90 by carrier methods.
This error can be minimized
by increasing the weight of carrier substantially, by using
:
strontium-85 for the estimation of yield, or by determining the
natural strontium present in the sample and correcting thecarrier
weight accordingly.
Frequently, it is sufficient to establish
that the natural strontium/calcium ratio in a particular type of
material is relatively low and hence introduces,
at most,
a
small error.
In addition to the requirement for analytical purposes,
\ results can be used in an alternate manner.
estimation of
‘discrimination factors!
They allow the
for strontium in the food
chain, or alternatively, if radiochemical data are available, the
pecific activity of strontium (strontium-90/natural strontium)
y be calculated for particular food chains.
This may sometimes
be preferable as it avoids the concept of ‘discrimination factor!
lor 'observed ratio',
This report outlines procedures for the estimation of
natural strontium, barium and calcium and presents results of the
determination of these elements in the: above mentioned matertals.
pond
Strontium and barium were determined by activation
oy
analysis.
Both elements form short-lived radioactive isotopes,