Between-bottle homogeneity test of new certified reference materials employing wavelength dispersive X-ray fluorescence spectrometry

Abstract

Background A pilot study has being carried out at our laboratories, with international collaborators, to develop seven certified reference materials (CRMs), which have matrices of mainly soil and biological tissues. The CRMs will be certified for macro-, micro- and trace elements for environmental, toxicological, agronomic and nutritional purposes. Homogeneity of element concentrations is a critical step in the production process of CRMs. This work employs wavelength dispersive X-ray fluorescence spectrometry (WD-XRF) to test between-bottle homogeneity of the CRMs. Results The relative standard deviation (RSD), relative average deviation, Skewness and Kurtosis of element contents in seven bottles out of 80 bottles of each CRM were considered to assess homogeneity in terms of variability and distribution. More than 50% of the number of quantified elements recorded RSD between 2 and 5%. Hence, based on an in-house classification, the intended CRMs recorded excellent to good between-bottle homogeneity. Nevertheless, the contents of some elements (Ni, Rb, Zn and Br) experienced high RSD values (> 10%). The Skewness and Kurtosis values of most elements are around one indicating symmetric distribution and thus have an absence of tailing relative to the normal distribution. Conclusions WD-XRF provides fit for purpose data for assessment of initial between-bottle homogeneity in terms of rapidity, ease of use, multi-element quantification and sample non-destruction. Electronic supplementary material The online version of this article (10.1186/s13065-019-0528-4) contains supplementary material, which is available to authorized users.

A review of laboratory, commercially available, and facility based wavelength dispersive X-ray fluorescence spectrometers

“…A between-bottle homogeneity test of certified reference materials investigated by Idris et al 49 was performed using the Magix PW 2403 (Malvern Panalytical, The Netherlands) wavelength dispersive instrument in a vacuum sample environment. Menne et al 50 used a MagixPRO (Malvern Panalytical) instrument to investigate ancient Neolithic pottery and to determine the elemental composition.…”