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

Particulate samples of a candidate reference material are evaluated on thei r homogeneity from bottle to bottle using electron probe X-ray microanalysi s technique. The evaluation on the homogeneity is done by the utilization o f the Kolmogorov-Smirnov statistics to the processing of the quantitative e lectron probe X-ray microanalysis data. Due to a limitation, existing even in computer controlled electron probe X-ray microanalysis, in terms of anal ysis time and expenses, the number of particles analyzed is much smaller co mpared to that in the sample. Therefore, it is investigated whether this te chnique provides representative analysis results for the characteristics of the sample, even though a very small portion of the sample is really analy zed. Furthermore, the required number of particles for the analysis to insu re a certain level of reproducibility, e.g. 5% relative standard deviation, is determined by the application of the Ingamells sampling theory. (C) 199 9 Elsevier Science B.V. All rights reserved.