The homogeneity of the reference sample used for electron microprobe x‐ray analysis is a crucial factor for the accuracy of quantitative determinations of the specimen content. The homogeneity assessment procedure based on Poisson statistics, that involves an x‐ray generation probability, fails to account for some error‐contributing factors.
An investigation technique is developed underlain by two‐factor dispersion analysis, in order to make an all‐round assessment of standards homogeneity involving all error‐contributing factors in analytical line intensity measurements. The homogeneity assessment data must comply with the current requirements for the quantitative analysis accuracy. The proposed technique was used to assess homogeneity of arsenopyrite specimens. Copyright © 2009 John Wiley & Sons, Ltd.