Abstract

Inductively coupled plasma time-of-flight mass spectrometry is ideally suited for use with flow injection because of its virtually simultaneous multi-elemental and multi-isotope capabilities. Here, novel flow injection strategies are employed for characterizing matrix interferences, as a diagnostic tool for detecting interferences and as a method for calculating the dilution factors necessary to overcome interferences. Gradient dilution flow injection allows rapid characterization of interferences and avoids problems that arise in steady-state evaluations, such as orifice clogging and baseline drift. Unfortunately, more severe matrix effects are obtained with this technique than in steady-state experiments. In addition, by calculating analyte ratios across the flow injection profile, it is possible to diagnose interference effects as well as to determine the dilution factors necessary for alleviating the interference. However, at this time, this ratio technique is not completely effective, as it is limited by element-specific dispersion curves. Unlike conventional interference approaches that are often time-consuming, these methods offer efficient alternatives for evaluating and possibly avoiding matrix effects.