Laser ablation inductively coupled plasma mass spectrometry of pressed pellet surrogates for Pu materials disposition

Successful Pu disposition by immobilization in glass or ceramic form requires accurate and precise knowledge of impurity amounts. Analysis of Pu material by conventional liquid nebulization requires dissolution, which is difficult due to the refractory nature of the samples. Laser ablation is a suitable sampling technique for direct analysis of solids. This paper demonstrates the procedures that were established for PuO2 analysis using laser ablation inductively coupled plasma mass spectrometer (ICP-MS). Pressed pellets prepared from CeO2 were used to simulate PuO2. Effects of laser conditions, sample preparation, and matrix composition, specifically mass of a matrix element and color, on the analyses of CeO2, Bi2O3, and PtO2 based pressed pellets were examined. Influence of mixing/grinding time on particle sizes, sample homogeneity, and ablation efficiency were investigated. Laser conditions that produce stoichiometric sampling were examined.