Determination of rare earth impurities in high purity europium oxide by inductively coupled plasma-mass spectrometry and evaluation of concentration values for europium oxide standard material

Direct determinations of 13 rare earth elements (La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Yb, Lu and Y) in high purity europium oxide by inductively coupled plasma mass spectrometry (ICP-MS) have been reported. The operating parameters of the instrument were optimized and the spectral interferences and the matrix effects were investigated. Using Ga or Rh as the internal standard can eliminate most of the matrix effects. The detection limits (3 sigma, n = 10, integral time = 1s) are 0.013-0.085 ng mL(-1) and the reproducibility (n = 11) is 0.9-3%. The recoveries of spiking samples are 80-108%. Europium oxide standard material was made and its concentration values were evaluated by various techniques from 10 collaborating laboratories. By comparison of the results of ICP-MS with the results of other techniques, we have validated that ICP-MS is an accurate and reliable technique for analysis of ultratrace impurities in high purity rare earth matrix.