NOTE Determination of 9Be in geological standard samples, JA-2 and JB-2, and of 9Be and 10Be in a basaltic rock sample for evaluation of uncertainty involved in 10Be/9Be ratio measurements

摘要

We determined the concentrations of 9Be in JB-2 and JA-2 geological standard samples using an inductively coupled plasma mass spectrometer (ICP-MS),, We determined 9Be abundance in standard samples of JA-2 and JB-2 as 2.26 ± 0.10 and 0.241 + 0.010 ppm, respectively, after comparing and selecting 9Be concentration data obtained by the internal standard method, the standard addition method and the column separation method. In the course of comparison, we identified a problem in the internal standard method, which is usually used for abundance analyses using an ICP-MS. Repeated analyses of a basalt lava gave a standard deviation of 10Be abundance of 9% (lcr, n = 5). From the results, we estimated the uncertainty of 10Be/9Be ratio as 10% (lo), considering a law of propagation of errors.