001893:
QE
The gross particulate and fallout samples were shipped to NRDL on
filter papers as collected in the field,
The size-separated samples were
prepared at UCRL by the oxygen burnoff and centrifuge technique des-
cribed in Section 2.4, and then transmitted to NRDL.
2 particle groups
were separated for the Koa and Oak samples and 3 for Walnut (see Appendix
B).
At NRDL the samples were prepared for analysis by wet ashing with
fuming HNO,
3
and HClO, to destroy organic material, then fuming with HF
to remove silica.
The HF was expelled by again fuming with HClO, and the
resulting solution was transferred to a volumetric flask and diluted to.
volume with 4N HCl.
analyses,
Aliquots of the HCl solutions were taken for the
A total of 1040 radionuclide determinations and 41 elemental
analyses (see Section 1.3.5) were performed at NRDL using the following
procedures;
1,
Elemental Na and Ca were determined with the flame photometer
using a matrix very similar to the constituents of coral,
2.
Mo?? was determined by either of two methods, depending on
the age of the sample.
A carrier-free anion exchange method (Reference
67) was used for fresh samples, while a modified precipitation method
(Reference 68) was used for older samples.
3.
eats
GAN BEEN
Eu!56, y?7}, and ce! 44 were measured by a cation exchange pro-
{