INVESTIGATIONS INTO NonspectrOSCOPIC EFFECTS of ORGANIC COMPOUNDS in inductively coupled plasma mass spectrometry

Polonca Kralj, Marjan Veber*

Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia

Abstract

Organic compounds introduced into an ICP-MS (inductively coupled plasma mass spectrometry) system can affect analysis in several ways. In our work nonspectroscopic effects caused by moderate concentrations of different organic compounds (methanol, acetonitrile, tris (hydroxymethyl) aminomethane, glucose, and ammonium acetate) were evaluated. The effect of carbon originating from volatile organic compounds on different processes in the plasma was found to be the most important reason for analyte signal changes. By varying instrumental parameters and using a mixed oxygen-argon plasma, it was confirmed, that high signal enhancements of Zn, As, and Se can be ascribed to the more efficient ionization, caused by C⁺ ions as modifiers.