Patent ID: 7361889

Claim:
A time of flight mass spectrometer for separately detecting different kinds of ions with respect to their mass to charge ratios by releasing the ions from an ion source, making them fly substantially along the same track once or multiple times repeatedly, and then introducing them into a detector, comprising: a) a measuring system for measuring flight times of the ions under at least two conditions differing in an effective flight distance between a point where the ions leave the ion source and a point where the ions enter the track or between a point where the ions leave the track and a point where the ions reach the detector, or differing in a state of a force acting within a field for accelerating or decelerating the ions traveling through the field; b) a peak identifier for comparing shapes of peaks in at least two flight time spectrums obtained through measurements with the measuring system and for identifying peaks resulting from the same kind of ion; and c) a processor for calculating a difference in the flight time between peaks that the peak identifier has identified as resulting from the same kind of ion, and for estimating the mass to charge ratio of an ion from the difference in the flight time.