Non-destructive analysis of small irregularly shaped homogenous samples by X-ray fluorescence spectrometry

A new calibration procedure is proposed for the non-destructive analysis of small sized samples of irregular shape by X-ray fluorescence spectrometry. The calibration is performed using normal calibration standards and measurements. The calculations for the calibration and the analysis of unknown samples are based on small modifications of existing procedures and software. The method was tested on fused bead samples as well as on pressed powder samples. The possibility to perform quantitative analysis on this type of samples is obtained at the cost of some accuracy. A relative root mean square error of 1.5% averaged over all elements tested was found in the new calibration procedure for the fused bead samples, versus 1.4% using the normal calibration procedure. For most elements the accuracy deteriorates somewhat except for sodium and magnesium. For the pressed powder samples the relative root mean square errors of the normal and newly proposed calibration method are comparable (average 3%), except for sodium, where there is an improvement from 15 to 7%.