This paper describes development work to prepare a method to measure absolu
te Pu-239 content and Pu-isotopics by ICP-MS in acidified Hanford DOE-site
samples which are very high in Sr-90, Tc-99, and Cs-137 radioactivity and w
hich are frequently high in organic carbon content. Samples with very large
Sr-90 and Cs-137 contents have historically been difficult to analyze for
Pu content by each of three alpha-counting techniques in use at SRS, and an
alysis by ICP-MS in these samples is complicated by the high organics conte
nt. We report an ion exchange chemical preparation to obtain fraction of Pu
that does not contain any fission product contribution and no interfering
organics to allow measure of absolute Pu-239 and of Pu-239 through Pu-241 i
sotopics by ICP-MS. The method uses a Pu-242 spike to measure Pu recovery a
nd is demonstrated in this paper with three distinct commercially available
resins and with over 300 samples. Measured absolute Pu-239 contents in six
ty-three spiked/unspiked duplicates have agreed within 15% precision. Overa
ll Pu-242 recoveries were near 90% with 25% precision. Comparisons of absol
ute Pu-239 contents measured directly on three samples agreed within the qu
oted 25% uncertainty.