Essential elements of time-of-flight mass spectrometry in combination with the inductively coupled plasma ion source

Time-of-flight mass spectrometry (TOFMS) is once again an important method of mass analysis. Commercial ICP-MS instruments with TOF mass analyzers have recently become available and this article provides an overview of key issues in the combination of TOFMS with the ICP source. The advantages of TOFMS for inductively coupled plasma mass spectrometry (ICP-MS) and the technological challenges in this combination are discussed in terms of basic principles of TOFMS. The concepts described include: sources of peak broadening; ion gating, duty-cycle and mass analyzer efficiency; signal digitizing in the nanosecond regime; comparisons with scanning mass analyzers; and selective quenching of ion signals in TOFMS.