Time-of-Flight Secondary Ion Mass Spectrometer (ToF-SIMS)

ToF-SIMS rasters a pulsed ion beam across an area to produce atomic, molecular, and fragment ions characteristic of the surface and near-surface region. This technique has low detection limits (low parts per million to high parts per billion for atomic species; as low as a femtomole for molecular species), excellent surface sensitivity (information depth is about 2 nanometers), and an extremely high mass resolution. While results are typically semi-quantitative, it can provide valuable insight into subtle chemical variations between similar samples.