Assessment of homogeneity of candidate reference material at the nanogram level and investigation on representativeness of single particle analysis using electron probe X-ray microanalysis

Abstract

Particulate samples of a candidate reference material are evaluated on their homogeneity from bottle to bottle using electron probe X-ray microanalysis technique. The evaluation on the homogeneity is done by the utilization of the Kolmogorov–Smirnov statistics to the processing of the quantitative electron probe X-ray microanalysis data. Due to a limitation, existing even in computer controlled electron probe X-ray microanalysis, in terms of analysis time and expenses, the number of particles analyzed is much smaller compared to that in the sample. Therefore, it is investigated whether this technique provides representative analysis results for the characteristics of the sample, even though a very small portion of the sample is really analyzed. Furthermore, the required number of particles for the analysis to insure a certain level of reproducibility, e.g. 5% relative standard deviation, is determined by the application of the Ingamells sampling theory.