Development of rational analytical technique of Sm by ICP-MS/MS

Horita, Takuma ; Akimoto, Yuji*; Do, V. K.  

Samarium-151(Sm) can be measured by liquid scintillation counting (LSC) or inductively coupled plasma mass spectrometry (ICP-MS). While the former method requires a complete radiochemical separation, the latter one must solve the isobaric interference from Europium-151 (Eu). In this study, we have been developing an analytical technique for Sm by ICP-tandem MS(ICP-MS/MS). The recent advances of MS/MS mode with a collision/reaction cell in mass spectrometry may enable sufficient removal of the mass spectroscopic interferences. Moreover, compared to LSC, ICP-MS is more rapid and more selective, and thus, it can simplify pretreatment process. As preliminary experiments, the selection of reaction gas for the separation of Sm from Eu were examined by checking the product ions of Sm and Eu produced by reactions with the various gases (H, O, NH, and NO). Our obtained data showed that in the reaction with NH, Sm formed a product ion at mass shift of 16, while the reaction tendency of Eu is different. Accordingly, the counts of Sm and Eu at the mass shift of 16 were 9842 [cps/g/L] and 162 [cps/g/L], respectively. The difference in reactivity of Sm and Eu to NH gas can reduce interference of the Eu to the measurement of Sm.