Isotope inter-elemental correction

Peel, K, Weiss, D., Chapman, )., Arnold, T., and Coles, B. (2008) A simple combined sample-standard bracketing and inter-element correction procedure for accurate mass bias correction and precise Zn and Cu isotope ratio measurements. J. Anal. 

The complexity of some of these problems of interference, matrix and inter-element fractionation is exemplified by the analysis of Sr isotopes in both solution mode and laser ablation (LA-) MC-ICP-MS. Sr isotope studies have been traditionally carried out using TIMS although MC-ICP-MS can also be used but requires correction (or monitoring) for mass bias, interfering elements, doubly charged ions, argides and dimers, and unidentified interferences. Primarily, isobaric interferences from Rb and Kr (present in trace quantities within the Ar plasma gas) must be corrected but this is not wholly straightforward. 

Since these early studies, efforts have concentrated on expanding the number of isotope systems to which LA-MC-ICP-MS can be applied, and mechanisms to correct for inter-element interference, mass bias and laser-induced isotopic fractionation. Where possible, internal normalisation of data using fractionation factors determined from a pair of stable isotopes of the element under investigation is the preferred route of data correction. Where this is not possible, external normalisation using another element at similar mass is used but, especially at light masses, this approach may not readily correct for laser-induced preferential volatilisation of lighter isotopes which may vary on an element-by-element basis. ... 

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