Determination of impurity elements in high-purity solid precursors based on tantalum pentoxide by inductively coupled plasma mass spectrometry

Conditions for the inductively coupled plasma mass-spectrometric (ICP MS) analysis of highpurity tantalum pentoxide and tantalum pentoxide doped with rare-earth elements without the separation of a sample matrix from analytes (Mg, Al, Si, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Sn, W, Gd, Dy, Er, and Pb) were determined. The metrological parameters of ICP MS analysis (accuracy, precision, and detection limits) were calculated. It was established that, in the analysis of test sample solutions with tantalum concentrations higher than 30 mg/L, a matrix effect appeared: the intensity of the measured ion current of analytes decreased against the background of a high concentration of sample matrix (tantalum) ions. This caused a proportional underestimation of the results of analysis. It was shown that it is reasonable to plot calibration functions against the background of a solution containing no more than 30 mg/L of tantalum ions. The results of the ICP MS analysis were compared with X-ray fluorescence (XRF) and optical emission spectrometry (OES) analysis data and calculation data on the amounts of admixtures introduced into tantalum pentoxide at the stage of the extraction preparation of a precursor. Keywords: high-purity tantalum pentoxide, tantalum pentoxide doped with rare-earth elements, inductively coupled plasma mass-spectrometric analysis, analytical signal intensity drift, standard and certified samples, metrological parameters DOI: 10.1134/S1061934814060069
The relationship between the impurity content and the properties of pure tantalum pentoxide is qualitatively and quantitatively ambiguous. Some of these relations can be predicted theoretically; however, as a rule, [...]