Study on homogeneity of multielements for a stream sediment matrix material with nuclear analytical techniques

Taking advantages of nuclear analytical techniques (NATs) with non-destruction, multielement capability, small and estimable uncertainties over a wide range of sample sizes, the sampling behavior of multielements for a home-made natural matrix material was studied with sample sizes ranging from several hundred mg down to tenths ng, namely nine orders of magnitude, by a combination of three NATs, neutron activation analysis (NAA), proton induced X-ray emission (PIXE) and synchrotron radiation X-ray flurescence (SR-XRF), in an effort to explore a procedure for the development of certified reference materials (CRMs) suitable for quality control of microanalysis. For accurately weighable sample sizes (> 1 mg), sampling uncertainties for 13 elements were found to be less than 1% by INAA. For sample sizes unable to be accurately weighed (< 1 mg), PIXE and SR-XRF were used, respectively. Sampling uncertainties were found to be less than 1% at sample sizes of tenth mg level for seven elements, and less than 10% on ng levels for three elements. Considering these three elements have satisfied homogeneity (sampling uncertainty less than 10%) at ng sample size level, any one of them can be served as a relative balance in sampling behavior characterization of multielements on sample size levels larger than ng (e.g., mu g level). On this basis, sampling uncertainties for nine elements were found to be less than 10% on mu g sample size level by INAA. The results indicate that the matrix is eligible as a candidate of CRMs suitable for quality control of solid sampling microanalysis.