TANDEM TOF MASS SPECTROMETER WITH PULSED ACCELERATOR TO REDUCE VELOCITY SPREAD

摘要

A tandem TOF mass spectrometer includes a pulsed ion source that generates a pulse of precursor ions from a sample to be analyzed. A first pulsed ion accelerator accelerates and refocuses a predetermined group of precursor ions. A first timed ion passes the predetermined group of precursor ions and rejects substantially all other ions. An ion fragmentation chamber fragments at least some of the precursor ions in the predetermined group. A second timed ion selector selects a predetermined range of masses centered on each precursor in the predetermined group and rejects all other ions. A second pulsed ion accelerator accelerates and refocuses the selected precursor ions and fragments thereof. An ion mirror generates a reflected ion beam. An ion detector detects precursor ions and fragments. A flight time from the second pulsed ion accelerator to the ion detector is dependent on a mass-to-charge ratio of selected precursor ions.