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-