An internal normalization technique for unmixing total-spiked mixtures with application to MC-ICP-MS

Isotopic analyses of a total-spiked sample by multiple-collector inductivel y coupled plasma mass spectrometry (MC-ICP-MS) are often corrected for mass fractionation by doping the sample with an external tracer element of know n isotopic composition and similar mass. However, because of the potential for elemental fractionation on the ICP-MS, internal normalization methods s hould be used whenever possible. Here, we present a weighted non-linear inv ersion of the mass spectra of a total-spiked sample, using linear, power, a nd exponential laws. This method was applied to the calibration of an Osmiu m tracer solution enriched in Os-190, and the results agree with iterative unmixing algorithms. (C) 2001 Elsevier Science Ltd. All rights reserved.