Instrumental Effects on Quantification by Compton and Rayleigh Peaks Ratio in TXRF Spectroscopy

In this study, we examined the impact of varying electric signal arrival rates in the detection chain on the intensities of Compton and Rayleigh peaks in TXRF spectra. The resulting intensity variations—caused by Dead Time—must be carefully accounted for when applying quantification methods that rely on either the relationship between Compton and elemental peak intensities or the relationship between Compton/Rayleigh peaks and elemental peak intensities. The TXRF technique, when using this quantification method, serves as an especially suitable analysis tool for quality control in production environments (in‐line metrology). This is because samples can be analyzed directly—without requiring standard addition—and in many cases, they need no sample preparation at all. However, to develop a reliable quantification procedure, the effects of Dead Time on both Compton and Rayleigh peaks must be accounted for in its overall impact across the entire spectrum, as was previously evaluated in an earlier study. The theoretical sources of quantification methods that use normalization to Compton or Rayleigh peaks are based on the photon interactions with matter. Therefore, we briefly described the main physical interactions that occur in TXRF spectroscopy. Our theoretical and experimental findings indicate that both types of quantification are reliable only if: (1) they are applied to samples from the same family (i.e., samples with very similar composition); and (2) when Dead Time is minimal and carefully controlled.