Patent ID: 8748811

Claim:
An MS/MS mass spectrometer including a first mass separator for selecting, as a precursor ion, an ion having a specific mass-to-charge ratio from various kinds of ions, a collision cell for dissociating the precursor ion by making the precursor ion collide with a collision-induced dissociation (CID) gas, and a second mass separator for selecting an ion having a specific mass-to-charge ratio from various kinds of product ions created by dissociation of the precursor ion, further comprising: a) a calibrating analysis execution means for collecting mass analysis data by introducing a CID gas into the collision cell, by operating the first mass separator to perform a mass scan of a sample having a known mass-to-charge ratio, and by operating the second mass separator to selectively analyze a product ion originating from the sample; b) a calibration information memory means for creating mass calibration information for the first mass separator, based on the mass analysis data collected by the calibrating analysis execution means, the mass calibration information reflecting a time delay of an ion in the collision cell, and for memorizing the mass calibration information; and c) an actual analysis execution means for collecting mass analysis data for a target sample by controlling a mass-scan operation of the first mass separator by using the mass calibration information memorized in the calibration information memory means, at least when a neutral loss scan or a precursor ion scan is performed.