Obtaining tandem mass spectrometry data for multiple stem ions in an ion population

摘要

A method of operating a mass spectrometer comprising an ion source, an ion trap having a plurality of elongated electrodes, a collision cell, and a time-of-flight analyzer, the method comprising the steps of: i) operating the ion source to generate ions having a first range of m / z values ; ii) introducing the ions generated by the ion source into the ion trap; iii) trapping ions introduced from the ion source in the ion trap; iv) ejecting ions within a second range of m / z values at right angles with respect to the longitudinal direction of the electrodes, during other ions are retained in the ion trap for subsequent analysis and / or fragmentation, so that the ejected ions migrate into the collision cell, the second region being narrower than the first region; v) fragmenting the ions introduced from the ion trap in the collision cell; vi) ejecting the fragmented ions from the collision cell, so d how these migrate to the time-of-flight mass analyzer; and vii) operating the time-of-flight mass analyzer to obtain a mass spectrum of the ions therein.