0018933
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 UCGRL 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, and HClO, to destroy organic material, then fuming with HF
to remove silica.
The HF was expelled by again fuming with HC10, 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,
26
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,
Eul56,
yl,
and
Ce
144
were measured by a cation exchange pro-