Avoiding polyatomic interferences in measurements of lanthanides in uranium material for nuclear forensic purposes

Measurements of the lanthanide series with ICP-SF-MS provide low detection limits but suffer from oxides of the lighter lanthanides interfering on the heavier ones. In this work, two different methods to measure the lanthanide series without interferences, were investigated and compared to measuring the lanthanides directly with a standard sample introduction system. It is shown that by using a desolvating sample introduction system during measurements, the impact of polyatomic interferences are eliminated. It is also shown that using chemical separations to separate the elements in the lanthanide series into three fractions almost eliminates polyatomic interferences, while direct measurements with a standard sample introduction system may lead to inaccurate results due to interferences.