Real-time adjustment of ICP-MS elemental equations

An MS Excel calculation procedure was set up to calculate the correction factors that are part of elemental equations used to correct for polyatomic and doubly charged ion interferences in the ICP-MS analysis of complex samples. The factors are calculated after the measurement of an interference check solution. For typical environmental and biomedical applications, a set of 5-6 check solutions is needed to be able to distinguish where the interference finds its origin. The calculation procedure compares the result for the quantitative isotope with the result for a control isotope (when feasible). Three cases for calculation are distinguished. The procedure also yields the right correction factors when there is some analyte contamination present in the check solution. The procedure lends itself to automation.