Energy dispersive x-ray fluorescence spectrometry for determination of twenty-six trace and two major elements in geochemical specimens

Abstract

A method for analyzing geochemical specimens by energy dispersive x-ray fluorescence is described. The fact is used that at any given x-ray energy between adjacent major element absorption edges, both the reciprocal of the specimen mass absorption coefficient and the spectral background intensity vary linearly with the intensity of the Compton scattered excitation radiation. Hence, Compton scattered excitation radiation serves a dual role: as an internal standard and as a measure of spectral background intensity. Several pure compounds, for which the x-ray cross sections vary over a wide range, are used to develop individual x-ray line spectral background curves. Standardization is achieved utilizing geochemical reference standards. Accuracies typically obtained are 5% or better using 20-in analysis periods.