What principle does TOF-MS utilize to determine mass?

Time-of-Flight Mass Spectrometry (TOF-MS) operates on the principle of flight time to measure the mass of ions. When ions are generated in a mass spectrometer, they are accelerated through an electric field. Once they enter the flight tube, the time it takes for each ion to travel from the source to the detector is recorded.

The key concept here is that lighter ions will travel faster and reach the detector before heavier ions due to their smaller mass. By measuring the time of flight for the ions, the mass-to-charge ratio (m/z) can be calculated. This relationship allows the instrument to effectively determine the mass of the ions based on how long they take to travel a set distance. Thus, flight time is essential to the functioning of TOF-MS and is the basis for determining the mass of the ions in the sample.