ICP-OES determination of major and trace composition of gadolinium(iii) oxide crystals doped with europium†

The ICP-OES method for determination of the main and trace composition of europium-doped gadolinium(III) oxide crystals from a single solution has been developed. Axial plasma viewing was used for trace analysis, and radial viewing was used for the Eu/Gd determination. Different variants of calibration solution preparation were compared: mixing aliquots and joint dissolution of samples. The parameters of spectra registration that minimized the relative standard deviation (RSD) of the emission intensities were selected; the results obtained using the “aliquot mixing” method coincided with the results of an electron microprobe analysis. The RSD in the Eu/Gd molar ratio is 1.5%. It is shown that the maximum ICP power provides minimum detection limits for trace elements at a Gd concentration of 1500 mg L⁻¹ in solution, amounting to n·10⁻⁶ to n·10⁻³% w/w for 52 elements.