Ensuring accuracy of ICP-MS analysis by using radioactive labels and gamma-ray spectrometry

Inductively coupled plasma mass-spectrometry (ICP-MS) with preliminary dissolving of the analysed sample is currently one of the leading methods of elemental analysis ensuring the highest analysis accuracy. In order to control quality and accuracy of multi-elemental ICP-MS analysis in geology, it has been proposed to use stable enriched isotopes to control the dissolution stage while determining problematic elements. The main downside of this approach is that it cannot be extended to mono isotope elements, such as Sc, Co, Mn, As, Y, Nb, Rh, Cs, Pr, Tb, Ho, Tm, Au, and others. At the same time, for understandable reasons the researchers have not considered using radioactive isotope labels for controlling yield of target elements during more complicated sample preparation procedures. The radionuclides used as a labels must meet the following requirements: a relatively short, but convenient for work flow half-life (approximately a day); a gamma-emitter with lines convenient for gamma-ray spectrometry; a high specific activity or a carrier-free radionuclide; can be generated with a nuclear reactor; if needed, ease of separation from the matrix. Elements interesting for ICP-MS analysis using radio labels application include mainly rare, refractory, noble, and several other elements. These are elements distinct by a relatively complex behavior in solutions, with conditions for stabilizing different elements in solutions sometimes being mutually exclusive. With the help of Active program , using differential cross-section and fast neutrons spectrum we have performed computer modelling of the yield of several radionuclides of interest that are formed via threshold reactions. The list of radionuclides that may be interesting for controlling metrological parameters of ICP-MS analysis is prepared. It has been experimentally shown that using radioactive labels and gamma-ray spectrometry for ICP-MS analysis of silicon samples and geological reference materials is an efficient tool that contributes to a higher analysis accuracy