Patent ID: 9576780
Date: 2017-02-21
CPC Classifications: G01N,H01J

Claim:
1. A mass spectrometer which sequentially introduces sample components which are temporally separated by a column of a chromatography into an ionization unit and performs mass analysis, comprising: a) mass spectrometry (MS) analyzer for repeatedly performing MS analysis on ions generated in the ionization unit; and a processor including b) chromatogram creation unit for creating a chromatogram that shows changes over time in an ion intensity within a predetermined mass range based on a result of the MS analysis; and c) timing determination unit for determining a timing to perform MS/MS analysis based on a signal intensity in the chromatogram; wherein the MS analyzer performs MS/MS analysis in which ions belonging to the mass range among ions generated in the ionization unit are adopted as precursor ions, in accordance with the timing to perform MS/MS analysis that is determined by the timing determination unit, wherein: the processor is configured to cause, when a signal intensity in the chromatogram reaches a predetermined upper limit after exceeding a predetermined lower limit, the timing determination unit to determine that point in time as the timing to perform MS/MS analysis, and when, after exceeding the lower limit, a signal intensity in the chromatogram arrives at a top of a peak without reaching the upper limit, the timing determination unit to determine that point in time as the timing to perform MS/MS analysis.