Overcoming interferences in inductively coupled plasma mass spectrometry via gas-flow modulation : Part 2. Correlation methods

Abstract

The second of two methods for reducing oxide interferences in inductively coupled plasma mass spectrometry is outlined. In both methods, manipulation of the central-channel gas flow generates unique behavior from analytes and interfering oxides that can subsequently be used to isolate signal contributions from both species superimposed at a given mass. Here, mathematical correlation between an interferent-compromised analyte response and an internal standard allows errors from troublesome interferences to be effectively eliminated. This correction method is capable of addressing multiple analyte–oxide interferences without sacrificing analyte sensitivity. A time-of-flight mass analyzer was used in this work to provide multi-elemental capabilities; however, the method is amenable to implementation on other simultaneous or scan-based mass analyzers.