Determination of Trace Fission Products Associated with Thorium and HCl Matrix by Inductively Coupled Plasma Mass Spectrometry after Anion Exchange Separation

For the determination of μg-mg L-1 of FPs in 100 g L-1 of thorium matrix with HCl medium, a method, including anion-exchange pre-separation, evaporation and inductively coupled plasma mass spectrometry (ICP-MS) measurement, was developed. The procedure parameters, such as the matrix effect of thorium, the acidity of separation, the elution curve of thorium and FPs and the temperature of evaporation were optimized by batch equilibration, column elution and evaporation experiments. It was found that the average recovery of the FPs was in the range 80 - 110%, and the RSD values were in the range 2 - 15% utilizing prior anion exchange separation of FPs from thorium samples. Furthermore, the detection limit of the method was also investigated.