Determination of Ultra-Trace Scandium, Yttrium and Rare-Earth Elements in High-Purity Iron by High-Resolution Inductively Coupled Plasma-Mass Spectrometry

Abstract

The determination of trace amounts of scandium, yttrium and Rare-Earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in high-purity iron by high-resolution Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was investigated. In using high-resolution ICP-MS, isotopes with overlapped mass numbers are distinguishable and all the rare-earth elements are simultaneously determined in one scanning. For the separation of iron, a liquid-liquid extraction method using 4-methyl-2-pentanone was investigated. Matrix iron could be transferred to the organic phase and analytes remained in the inorganic phase. Moreover, ng levels of these elements in high-purity iron could be determined. The proposed method could be applied to determination of ultra-trace of scandium, yttrium and Rare-Earth elements in high-purity iron, and ng.g–1 (ppb) or under ppb level detection limits were obtained.