Mass spectrometer

摘要

A product ion spectrum is created on the basis of MS2 analysis data respectively obtained for a parent compound and a metabolite. Additionally, a neutral loss spectrum, in which the mass of each product ion is replaced with a mass difference between the mass of the product ion and that of a precursor ion, is created. Then, a common peak having the same mass on the neutral loss spectrums of both the parent compound and the metabolite is extracted, and a complementary peak appearing on the product ion spectrum of the metabolite is extracted; this peak appears at a position corresponding to the difference between the mass of the common peak and that of the precursor ion. The ion corresponding to the complementary peak is designated as a precursor ion for the next MS3 analysis, and this MS3 analysis is performed.

主权项

1. A mass spectrometer comprising:
a mass analyzer that performs an MSm analysis (where m is an integer greater than two) to obtain mass analysis data for each of a first compound and a second compound; and a data processor configured to
a) create an MSm-1 spectrum based on mass analysis data obtained by an MSm-1 analysis performed for each of first and second components by the mass analyzer;b) calculate, for each of the two MSm-1 spectrums, a mass difference between a mass of each peak among some or all of peaks appearing on the MSm-1 spectrum and a mass of a precursor ion, and for creating an MSm-1 mass-difference spectrum having a peak at each of the calculated mass differences;c) extract a common peak having a same mass in the two MSm-1 mass-difference spectrums relating to the first component and the second component; andd) extract a complementary peak on the MSm-1 spectrum relating to the first component and/or the second component, the complementary peak corresponding to a mass difference between the mass of the precursor ion and the mass of the common peak; and an analysis controller that receives an information of the complementary peak from the data processor; determines a candidate of the precursor ion for an m−1-th stage of a dissociation operation in the MSm analysis based on the information; and controls performance of the MSm analysis by the mass analyzer to perform the MSm analysis on the first component and/or the second component with the determined candidate of the precursor ion designated as a precursor ion for an m−1-th stage of the MSm analysis.