Mass spectrometer

Patent metadata

Field	Value
Publication number	US-9672330-B2
Application number	US-73933510-A
Country	US
Kind code	B2
Filing date	Oct 23, 2007
Priority date	Oct 23, 2007
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A product ion spectrum is created on the basis of MS 2 analysis data respectively obtained for a parent compound and a metabolite (S 1 and S 2 ). 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 (S 3 ). Then, a common peak having the same mass on the neutral loss spectrums of both the parent compound and the metabolite is extracted (S 4 ), and a complementary peak appearing on the product ion spectrum of the metabolite is extracted (S 5 ); 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 MS 3 analysis (S 6 ), and this MS 3 analysis is performed (S 7 ). By a dissociation operation, if a portion common to the parent compound and the metabolite is desorbed in the form of a neutral molecule while a different portion remains in the form of an ion, an MS 3 analysis in which the ion of the different portion is used as the precursor ion is performed to obtain structural information of a site of metabolism.

First claim

The invention claimed is:

1. A mass spectrometer, comprising:
a mass analyzer unit that provides an MS n analysis (where n is an integer greater than two), the mass analyzer unit including an ion source and a detector, and the mass analyzer unit performing MS m−1 analysis (where m is an integer greater than two and no greater than n) on a first component and a second component to obtain mass analysis data for the first component and mass analysis data for the second component from the detector and performing an MS m analysis including a dissociation operation on the first component and/or the second component;
a controller configured to control the dissociation operation; and
a data processor configured for
a) creating an MS m−1 spectrum (where m is an integer greater than two and no greater than n) based on the mass analysis data for the first component, and creating an MS m−1 spectrum based on the mass analysis data for the second component;
b) extracting a common peak having a same mass to charge ratio in the two MS m−1 spectrums relating to the first component and the second component;
c) either excluding an ion corresponding to the common peak, or giving a low degree of priority to this ion, as a candidate of a precursor ion for an m-1-th stage of the dissociation operation in the MS m analysis on the first component and/or the second component;
d) designating an ion corresponding to a complementary peak as the precursor ion for the m−1-th stage of the dissociation operation in the MS m analysis on the first component and/or the second component while excluding or giving a low degree of priority to the ion corresponding to the common peak; and
e) acquiring a subsequent MS m spectrum from the dissociation operation.

2. A method of providing an MS n analysis (where n is an integer greater than two), comprising:
a) performing MS m−1 analysis (where m is an integer greater than two and no greater than n) on a first component and a second component using a mass spectrometer, including an ion source and a detector, to obtain mass analysis data for the first component and mass analysis data for the second component from the detector;
b) creating an MS m−1 spectrum (where m is an integer greater than two and no greater than n) based on the mass analysis data obtained by the MS m−1 analysis performed for the first component, and creating the MS m−1 spectrum based on the mass analysis data obtained by the MS m−1 analysis performed for the second component;
c) extracting a common peak having a same mass to charge ratio in the two MS m−1 spectrums relating to the first component and the second component;
d) either excluding an ion corresponding to the common peak, or giving a low degree of priority to this ion, as a candidate of a precursor ion for an m−1-th stage of a dissociation operation in an MS m analysis on the first component and/or the second component,
e) designating an ion corresponding to a complementary peak as the precursor ion for the M−1-th stage of the dissociation operation in the MSm analysis on the first component and/or the second component while excluding or giving a low degree of priority to the ion corresponding to the common peak;
f) performing the MS m analysis including a dissociation operation on the first component and/or the second component using the mass spectrometer; and
g) acquiring a subsequent MS m spectrum from the dissociation operation.

Assignees

• Yamaguchi Shinichi
• Shimadzu Corp

Inventors

• Yamaguchi Shinichi

Classifications

• H01J49/0027

  Methods for using particle spectrometers · CPC title

• G16C20/20 Primary

  Identification of molecular entities, parts thereof or of chemical compositions · CPC title

• H01J49/004

  Combinations of spectrometers, tandem spectrometers, e.g. MS/MS, MSn · CPC title

• G01N33/6848

  Methods of protein analysis involving mass spectrometry · CPC title

• G06F19/703 Primary

  Physics · mapped topic