A simple method for quantitative analysis of elements by WD-XRF using variable dilution factors in fusion bead technique for geologic specimens

Abstract

A common approach in the quantitative analysis of geological samples by X-ray fluorescence is to establish calibration lines for elements of interest by using several reference materials (RMs) and/or the combination of RMs and pure chemicals. Herein, we introduce an alternative to use only two RMs, to establish a calibration application. Variation of the dilution factor is employed to generate a dynamic range of concentrations for each RM and to evenly furnish the calibration lines to analyze certain matrices. A wide range of dilution factors were employed from 2–54 times dilution (with respect to the flux to sample ratios). Calibration lines for the major elements including: Si, Al, Ca, Fe, Mg, Na, Mn, and Ti show an extremely high level of linearity with all elements. R2 values greater than 0.9990 were obtained for each analyzed element. The calibration application was validated by checking against a variety of geological RMs including petroleum and carbonate rich shale (SGR-1), Muscovite rich marine shale (SBC-1), metamorphic rock (SDC-1), carbonatite (COQ-1), and types of igneous rocks (GSP-2, BCR-2, AGV-2, QLO-1, and W-2). Mixtures of Alumina and Silica (ARG-1 and ARG-2) and pure SiO2 beads were also analyzed to further check the application. Rigorous statistical analysis on the RMs confirms the reliability of the calibration application for the employed matrices. Copyright © 2016 John Wiley & Sons, Ltd.