Using Ion-Molecule Reactions for Removal of Spectral Interferences to Achieve Accurate Measurements that Improve your Processes

X. Ma, C. Stephan
PerkinElmer Inc.,


Cerium oxide (CeO2) is used as an additive in the glass industry, as an abrasive material for plate glass, and in the grinding of spectacle glass, optical lens, and picture tubes. The purity of cerium oxide is usually required to be as high as possible, mandating the accurate determination of REE impurities in CeO2 at ultralow levels. One of the biggest challenges in the analysis of impurities in purified CeO2 is that the impurities are often present as spectral interferences (CeO+, CeOH+, CeH+, CeOH2+). By using ICP-MS with multi-quadrupole functionality, other ions residing on the mass of interest are not allowed to enter the collision-reaction cell. In order to address these interferences to the levels required for ultra trace analysis, reaction gases, such as NH3, can be used to react with either the interference or the analyte ions in the cell such that the interference is removed by ion-molecule reaction.