Abstract:

Inductively coupled plasma (ICP) source was applied success fully to the direct spectrographic determination of trace amounts of 14 rare earth elements in high purity Y₂O₃.A simple method was suggested to study the effect of the matrix concentrations on detection limits.Spectrographic conditions were as follows: Chinese Ebert type spectro-graph (WPG-100), linear dispersion 3.6 Å/mm (second order); Chinese radio frequency generator (GP3.5-D1), frequency 33 MHz, anode voltage 3.5 kV, anode current 0.9 A, grid current 0.22 A; Scott-Fassel type plasma torch, pneumatic concentric nebulizer, carrier gas Ar 0.77 1/min, plasma gas Ar 0.5 1/min, coolant gas Ar 14 1/min, observation height 15-16mm. Samples were dissolved simply in HC1 (6N) and diluted before determination.The lower limits of the determination were 0.3-3μg/g (as oxides) for the rare earth impurities, except 7μg/g for CeO₃ and 17μg/g for Pr₆O₁₁ Yttrium oxide with 99.995% purity could be analysed. The relative standard deviations were 2.3-7.3%, when the concentrations of rare earth oxides (except Pr₆O₁₁ and CeO₂) were 3-17μg/g. Effects of rare earths and 13 non-rare earths (Ca, Mg, Al, Fe, Na etc.) impurities on results of determination might be often neglected.