ABSTRACT
This chapter takes a detailed look at the inductively coupled plasma mass spectrometry (ICP-MS) ion-focusing system—a crucial area of the ICP mass spectrometer where the ion beam is focused before it enters the mass analyzer. It comprises one or more ion lens components, which electrostatically steer the analyte ions in an axial or orthogonal direction from the interface region into the mass separation device. The strength of a well-designed ion-focusing system is its ability to produce a flat signal response over the entire mass range, low background levels, good detection limits, and stable signals in real-world sample matrices. The role of the ion-focusing system is therefore to transport the maximum number of analyte ions from the interface region to the mass separation device, while rejecting as many of the matrix components and non-analyte-based species as possible. It is absolutely critical that the composition and electrical integrity of the ion beam be maintained as it enters the ion optics.
