Matrix Effect Corrections in X-ray Fluorescence Spectrometry

摘要

X-ray fluorescence is subject to significant matrix effects, which must be corrected in order to obtain accurate quantitative results. These are due to both absorption and enhancement effects, which are a consequence of the fact that both the analyte and the matrix absorb and fluoresce in the X-ray region, and this affects the magnitude of the analyte signal. Instruments, especially hand-held energy-dispersive X-ray analyzers designed for use by nontechnical personnel, typically come with software that use general algorithms that apply the appropriate matrix effect corrections without user involvement. Though user-friendly, this approach obscures the steps needed to obtain accurate quantitative results. In this laboratory exercise students obtain X-ray fluorescence data for both elements in binary mixtures of metal powders. The matrix effect is corrected using the analyte and matrix measurement data and a simple influence factor model. The exercise gives students a better sense of matrix effects and illustrates one approach to correcting for them.