Patent ID: 7544930

Claim:
A tandem type mass analysis system having a reference data base for storing data based on mass analysis spectra of a reference specimen, a chromatography unit for separating the substances included in the specimen, an ionizing unit for ionizing the substances included in the specimen, an ion dissociating unit for dissociating the ions, an ion separating unit for separating the dissociated ions, an ion detecting unit for producing mass analysis spectra by detecting the separated ions for each mass charge ratio m/z, and a data processing unit for comparing the mass analysis spectra obtained by the ion detecting unit with the mass analysis spectra stored in the reference data base, wherein mass analysis is carried out with the all ion species included in the specimen in each mass charge ratio m/z region being dissociated for each of a plurality of preliminarily set up mass charge ratio m/z regions, the measurement MS 2 data as the mass analysis spectra obtained thereby are compared with the reference MS 2 data as the mass analysis spectra of a corresponding reference specimen stored in the reference data base, in the case there is a difference therebetween, mass analysis MS 1 is carried out without dissociating the all ions included in the measurement MS 2 data with the difference for presuming an ion to be the cause of the difference therebetween, and the measurement MS 1 data as the mass analysis spectra obtained thereby are compared with the reference MS 1 data as the mass analysis spectra of a corresponding reference specimen stored in the reference data base.