Patent ID: 8242437
Filing Date: 2012-08-14
Classification: H01J

Abstract:
1. An MS/MS mass spectrometer comprising, in a vacuum chamber: a first mass separation unit for selecting ions having a specific mass-to-charge ratio as precursor ions from among various species of ions; a collision cell for dissociating the precursor ions by making the precursor ions collide with a collision-induced dissociation gas; and a second mass separation unit for selecting ions having a specific mass-to-charge ratio from among various species of product ions generated by the dissociation, wherein the configuration of wall surfaces in the collision cell provides a gas conductance on a side of an injection end face of the collision cell having an ion injection aperture for injecting ions into the collision cell that is smaller than a gas conductance on a side of an exit end face of the collision cell having an ion exit aperture for discharging ions from the collision cell so as to produce in the collision cell a flow of the collision-induced dissociation gas having a component of flow vector in a same direction as a passage direction of the ions injected through the ion injection aperture.