Patent ID: 8258465

Claim:
A mass spectrometry apparatus designed to determine one or more precursor ions based on an MS n−1 spectral data acquired through an MS n−1 analysis, and inducing fragmentation of the precursor ions to perform an MS n analysis (wherein n is an integer of 2 or more), the MS n−1 spectral data including a plurality of peaks, comprising: a) setting means operable to allow a user to input and set an upper limit and a lower limit value of a signal intensity on an MS n−1 spectrum, or to directly input and set an intensity range having upper and lower thresholds of a signal intensity on an MS n−1 spectrum; b) peak sorting means operable to select and sort all peaks of the MS n−1 spectral data having a peak intensity which falls within an intensity range defined by the upper and lower limit values or the directly input/set intensity range; and c) analysis control means operable to controllably allow an ion having a mass corresponding to the peak sorted by the peak sorting means to be selected as a precursor ion so as to perform the MS n analysis.