Rare earth elements (REEs) comprise a group of 17 elements that span the lanthanide series from lanthanum (La) to lutetium (Lu), including scandium and yttrium. Among these, terbium oxide (Tb4O7) is an important REE compound that has a variety of uses across modern-day technologies. Its purity is usually required to be as high as possible, mandating the accurate determination of other REE impurities in Tb4O7 at ultra-low levels.
Due to the low concentrations that must be measured, inductively coupled plasma mass spectrometry (ICP-MS) has long been valued as the technique of choice for analyzing impurities in high-purity rare earth oxides. However, analysis by ICP-MS can be challenging due to polyatomic spectral interferences from matrix elements.
This work demonstrates the ability of the NexION® 1100 ICP-MS to directly and effectively measure 13 trace REE elements in 500 ppm Tb4O7 solution, thanks to the capability of its quadrupole Universal Cell to control the reaction to ensure that no new interferences are formed. Its robust instrumental design allows the analysis of concentrated and challenging matrices, such as high-purity rare earth oxides.