Determination of fluorine in solids down to 120 μg/g by wavelength dispersive X-ray fluorescence spectrometry

Abstract

An X-ray fluorescence spectrometric method is described for the determination of fluorine from percent level down to 120 μg/g in fluoropolymers and in fluoride samples. The method is based on the measurement of the intensity of first order\(FK_{\alpha _{1,2} } \) line for 30 seconds using a flow proportional counter and a multilayer AXO6 crystal (2d=5.52 nm). The calibration curves of first degree base polynomials are linear over the concentration range of 8000–120 μg/g and of 48.92–76% measured. The precision and accuracy obtained for polymer samples in percent level of fluorine are up to ±≥0.5 and within ±≥1%, respectively. However, the precision (δ) for trace concentrations is in the range from 8 to 20%. In most cases the accuracy is up to ±7%, ±5% and ±4% in the concentration range of 120–8000 μg/g, 801–8000 μg/g and of 120–400 μg/g, respectively. The time needed to analyze one sample including calibration and regression analysis is about 8 minutes.