X-ray fluorescence analysis of major, trace, and rare earth elements in silicate rocks using the low-dilution glass bead method

Abstract

This paper reports on updates to the system used for quantitative analyses of major, trace, and rare earth elements in silicate rocks by X-ray fluorescence spectrometry (RIX3000) at the National Institute of Polar Research. We added Sc and Th to the list of measured elements, and the overlap coefficient of Th is used for the measurement of Nb. The geochemical standard samples SY-3 (Canada) and JCh-1 (Japan) have been added to the existing set of standard samples to improve the precision of analyses of SiO_2 and rare earth elements. Furthermore, we established a new method of evaluating the analytical error, making it possible to use analytical data for geochemical evaluation while considering the precision of the data. We also found that the analytical error may increase as a consequence of using a different lot number of the flux used in preparing the fused glass beads. It is therefore necessary to assess the background of the flux as well as the target elements, in terms of whether they are within the analytical error, before using a new flux.