[Determination of phosphorus and iron in cocatalyst for maximum propylene production by X-ray fluorescence spectrometry].

The aim of the authors' research work was to develop a new technique for quantitative analysis of phosphorus and iron contents in cocatalyst by X-ray fluorescence spectrometry (XRFS). A set of standard samples synthesized were prepared for the experiments with this purpose when the interferences of inter-elements had been corrected by empirical coefficient method. The standard samples were manually synthesized, and the powder pellets were used for sample preparation and the matrix effects were corrected by the experience coefficients. The characteristic X-rays of phosphorus and iron elements could selectively be determined with the enhanced accuracy and reduced time consumption within a range without signal interference from main-component elements. Manufacturing sample and measurement conditions of the new method was brought up; the matrix effects of cocatalyst samples were verified by empirical coefficient method. The results of experiment show that the accuracy and precision of this method satisfactorily had the high repeatability. The measuring ranges of elements were omega 0.01%-2.5% for phosphorus and omega 0.01%-2.5% for iron with the relative deviations of 0.34% for phosphorus and 0.59% for iron, respectively. This method showed satisfied accordant results compared with the chemical method and inductively coupled plasma (ICP). It has provided the analytical values for phosphorus and iron in cocatalyst for maximum propylene production. This new method has the advantages of satisfactory accuracy, high precision, less interference, easy sample handling and efficiency. In addition, the samples are not decomposed during the analysis process when each sample only requires 5 minutes for measurement This new method will be able to meet the growing demands of quantitative analysis of phosphorus and iron content in cocatalysts. This method had the satisfactory accuracy and precision, the analytical range was large, and had been successfully applied to the determination of phosphorus and iron in cocatalyst.