Quantification of calcium, phosphorus, and cerium in novel biocompatible materials by total reflection X-ray fluorescence spectroscopy

Abstract

An approach to the determination of the composition of novel biocompatible materials based on cerium-containing calcium phosphates by TXRF is proposed. The ranges of analyte contents in solutions for the correct determination of Ca, P, Ce by the external standard method were determined. A systematic underestimation of the calcium signal at a Ca content in the analyzed composite sample above 30 mg/liter is noted. The Compton scattering spectra for the ceramic sample solution were analyzed to assess the compliance of the sample with the thin layer criterion, the maximum value was 16. 8 keV (96°). According to the graph of the mass attenuation coefficient for a film of a given composition, the attenuation of the calcium line is not related with the absorption effect of the sample. The internal standards (Gd and Cu) were selected and conditions for the determination of micro- and macro-components in solutions and suspensions of samples were determined. It is shown that with a calcium content up to 50 mg/liter in the sample, it is possible to determine correctly Ca, P, and Ce by TXRF method in solutions and suspensions with Sr 0.05 and 0.09, respectively. The convergence of the results obtained is noted by the methods of external and internal standards with appropriate dilutions of solutions and suspensions.