A theoretical procedure to determine coefficients from the Rasberry–Heinrich calibration curve in XRF spectroscopy

Relative X‐ray fluorescent intensity data have been generated numerically for binary samples under mono‐chromatic excitation in those cases of absorption plus enhancement that are dealt with in this work. These data were fitted to the empirical Rasberry–Heinrich equation, keeping both coefficients different from zero, since from our numerical calculations it is shown that in most cases the best fit is achieved when A ≠ 0. Furthermore, this approach shows that a third coefficient introduced into the empirical equation improves the fitting. The aforementioned results suggest that the empirical equation could be deduced from the theoretical equation of fundamental parameters under suitable approximation. The result is an equation similar to that of Rasberry and Heinrich, from which analytical approximated coefficients are obtained. It is then possible to calculate a calibration curve using fundamental parameters values. Copyright © 1981 Heyden & Son Ltd.