Digital Computer Calculation and Correction of Matrix Effects in X-Ray Spectroscopy

A multiple regression technique has been employed to calculate equations correlating x-ray fluorescent intensities with composition for complex sample matrices. The technique has been applied to a variety of materials containing major and minor components with a wide range of atomic numbers. Equations for the concentration of elements as functions of the fluorescent intensities of the sample constituents are developed to calculate concentrations without the need for calibration curves. The equations themselves are programmed for computer calculation, permitting complete computer determination of sample composition from measured intensities. In order to predict matrix effects, equations are also developed for the fluorescent intensities of elements as a function of the sample composition.