Overcoming interferences in inductively coupled plasma mass spectrometryvia gas-flow modulation Part 1. Fourier transform methods

Abstract

The first of two new methods for reducing oxide interferences in inductively coupled plasma mass spectrometry is described. This method utilizes careful manipulation of the central-channel gas flow to impart distinguishable frequency-specific behavior to analyte and oxide species. Subsequently, application of a Fourier transform (FT) permits contributions from the analyte and oxide superimposed at a given mass to be unraveled. Through application of this correction method, a greater than ten-fold error at m/z 156 caused by the interference of ¹⁴⁰Ce¹⁶O⁺ on ¹⁵⁶Gd⁺ has been effectively eliminated. This correction method is well suited for overcoming multiple analyte–oxide interferences (most notably where monoisotopic elements have been compromised) in a simultaneous manner. Although a time-of-flight mass analyzer was utilized here, this correction method is well suited also for implementation with scan-based systems (e.g. quadrupoles and sector-field mass spectrometers).