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CRER-1068
Table II presents the results of a series of determinations of calcium in wheat, obtained by modifications of the
classical oxalate procedure.
High values were invartably obtained,
even titrimetrically, if the oxalate was precipitated without
prior removal of silica.
Double precipitation (Table I and column
3, Table II) eliminated the occasional, erroneously high value
which may have resulted from occlusion of magnesium oxalate in
the first precipitate.
2.
Determination of Barium Yields
A comparison of strontium and barium losses was made by.
adding strontium carrier and barium-139 tracer to four different
samples and then carrying out the chemical separation as outlined in Appendix 1.
gravimetrically.
The strontium.yield was determined
The yield of barium-139 was determined by comparing
the barium activity recovered in the final strontium carbonate
precipitate with that added to the sample.
The results appear in
Table III.
The recovery of barium, measured with barium-139 tracer,
was consistently lower than the gravimetric yield of strontium and
averaged 94% of the strontium yield in the four samples studied.
This factor has been used as a correction in the estimation of
the barium content.
3.
Accuracy of the Results
The strontium and barium analyses and a portion of the
calcium analyses were done in duplicate in order to estimate
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