ICP mass spectrometry (ICP-MS) is the most powerful technique for the determination of elements at the (ultra)trace level. Most ICP-MS instruments are equipped with a quadrupole filter for mass analysis. With a quadrupole filter, the intensity for only one nuclide can be measured at any given time because at any given time only ions are transmitted within a narrow mass range (about half an atomic mass unit). For multi-element determination, scanning (continuous shifting of the mass window) or peak jumping (discontinuous shifting of the mass window) must be used. ToF-ICP-MS is a version of ICP-MS in which a time-of-flight (ToF) analyzer is used for mass analysis. In a ToF analyzer, ions are introduced pulsewise after acceleration to a constant energy. For each pulse, a (nearly) complete element mass spectrum is obtained because the ions reach the detector separated in time according to their ratio of mass to charge. The processing of such a pulse takes only 33 microseconds. This makes ToF-ICP-MS especially interesting in applications with short-lived transient signals. A first example is laser ablation ICP-MS for revelation of the spatial distribution of elements in 2 dimensions across the sample material. A complete element spectrum can be obtained for each pixel of the corresponding "elemental map" even for transient signals with duration <0.5 milliseconds. A second example is single-event ICP-MS, in which a dilute suspension containing individual small entities such as engineered nanoparticles (ENPs), cells of bacterial, plant, animal or human origin, or microplastic particles is introduced. Each time such an individual particle enters the ICP, it gives rise to a transient signal with a duration of about 0.5 microseconds. Notwithstanding this short duration, a full element spectrum can be obtained for this signal. Disadvantages of ToF-ICP-MS over quadrupole ICP-MS are a lower sensitivity and a more limited linear dynamic range.