Determination of Rb, Sr, Cs, Ba, and Pb in K‐feldspars in small sample amounts by total reflection X‐ray fluorescence

The results of the determination of Rb, Sr, Cs, Ba, and Pb in K‐feldspars by total reflection X‐ray fluorescence analysis using 0.05 g sample in mass are presented. Prepared suspensions of the rock Certified Reference Materials and the K‐feldspar samples were chosen as the sample preparation method. Studying the particle sizes of the K‐feldspar sample powders was carried out. The concentrations of the elements were evaluated using the internal standard method. As internal standard, either a Se solution was added to the sample or the concentration of Rb was preliminary determined or known, have been used. The accuracy of the element determinations was estimated by comparison between obtained and certified values of the elements determined in the Certified Reference Materials of the K‐feldspars, such as JF‐1 and JF‐2.