Determination of Elements in the Energy Range 13–15 keV by Newly Investigated EDXRF With an Ellipsoidal Highly Oriented Pyrolytic Graphite Crystal

ABSTRACT Because some highly toxic actinides cannot be easily analyzed in general laboratories, Rb, Sr, and Y with similar X‐ray energies are commonly used to simulate actinides. Here, a quantitative K‐X‐ray analysis of the Rb, Sr, and Y simulation was performed using a highly oriented pyrolytic graphite crystal. The ellipsoidal crystal increased the signal‐to‐noise ratio and eliminated exposure of the detector to high‐energy radiation. As a band‐pass energy filter, the crystal selectively diffracted X‐rays in the range 13–15 keV needed for Rb, Sr, and Y detection. Their detection limits in the aqueous phase were < 0.05 mg/L, while their relative standard deviations were < 0.6% in 10 mg/L samples.