Development of matrix correction procedures in the field of X-ray spectral analysis leads usually to “universal” algorithms which allow use of a common calibration equation for assay of various materials with different composition and concentration ranges. In many applications, such methods can guarantee accuracy of 3-5% rel.

For X-ray analysis of automotive catalysts, one such technique is based on the theoretical correction of interelement effects. The article states that “the overall accuracy of this approach is about 10% relative error, although this may vary depending upon the particular specimen being analyzed.” However, narrow specification limits for the quality control of catalysts require the total error of analysis less than 1-1.5% rel.