Multivariate quantification of spectroscopic interferences caused by sodium, calcium, chlorine and sulfur in inductively coupled plasma mass spectrometry

A new method for quantification of spectral interferences in ICP-MS, based on empirical modelling and experimental design, is presented. The relations hip between interfering effect and matrix composition is deduced by perform ing a multiple linear regression analysis and taking into account linear an d quadratic effects of matrix elements and all the potential interactions b etween them. In order to separate spectroscopic from non-spectroscopic inte rferences, analyte isotope ratio measurements were performed, except for mo noisotopic elements for which the signal ratio (ratio between signal measur ed with and without matrix) was considered and internal standardization app lied. Spectral interferences caused by sodium, calcium, chlorine and sulfur species, at the m/z of interest for the determination of several isotopes (V-51, Cr-52, Cr-53, Ni-58, Ni-60, Ni-62, Co-59, Zn-64, Zn-66, Zn-68, Cu-63 , Cu-65, As-75, Cd-111, Cd-114, Pb-207 and Pb-208) were modelled and are di scussed.