Multisignal evaluation in ICP-MS

Abstract

The existence of isobaric and polyatomic ion interferences has been considered to be a significant shortcoming of inductively coupled plasma – mass spectrometry (ICP-MS). In the special case of Mo-Zr-alloys problems caused by polyatomic ions are substantial. The determination of trace elements by using classical univariate linear regression of single signals or any correction equations presented by the instrumental software is impossible. There are various possibilities to overcome spectral interferences, in principle. The application of high-resolution ICP-MS, separation methods or alternative sample introduction systems is limited by the high cost and the apparative expenditure. In this report methods of multisignal calibration, like partial least squares (PLS) regression and canonical correlation analysis (CCA), are used to overcome isobaric or chemical interferences in ICP-MS. It is shown, that PLS and CCA are able to handle or tolerate, respectively, spectral interferences existing in a Mo-Zr-O-H-F system. The results of quantitative analysis provided by PLS and CCA were comparable.