Background Intensities and Their Utilization in Quantitative Analysis by Monochromatically Excited Energy-Dispersive X-Ray Fluorescence

In monochromatically excited energy-dispersive X-ray fluorescence spectrometry, the spectral background has mainly been investigated for a better understanding of its origin and nature, or with the aim to reduce its magnitude for an improvement of detection limits.

The observation that the background intensity can largely be ascribed to a residual polychromatic fraction of the exciting radiation has led to the derivation of an empirical relationship between the scattering characteristics of a sample and the observed background intensity. This dependence constitutes the basis of a matrix correction procedure useful for samples with a considerable fraction of light elements.

Two algorithmic variations are presented: one that relies on the definition of a single matrix element, and a second one that can be used in conjunction with the measurement of the incoherently scattered exciting radiation. These options are useful if direct quantification of either or both scatter peaks is not feasible.

Results are presented for a variety of Standard Reference Materials.