US 8,026,476 B2Granted

Mass analyzing method

AssigneeShimadzu Corporation

InventorShinichi Yamaguchi

Life of this patent

Estimating the term…

Loading patent…

Abstract

When the analyzer provides the mass and composition formula of the product ion, which is probably produced in the process of a dissociation, through the input unit, based on known information, a composition formula list is created in the database. When a product ion is obtained in an MSn analysis, the data processor checks whether or not the ion's mass exists in the composition formula list, and in the case where it does, the composition formula corresponding to the mass is determined. Then, based the mass difference between the precursor ion and product ion or other factors, the precursor ion's composition formula is deduced, and if it is possible to ultimately narrow down the candidates for the target ion's composition formula, the analysis is terminated. Accordingly, if the composition formula list is available, the refinement operation for the candidates for the composition formula can be omitted.

Claims11

Dependent claims

A mass analyzing method, using a mass spectrometer capable of an MSn analysis in which a precursor ion originating from a target substance is dissociated for n−1 stages (where n is an integer equal to or more than two) and a product ion generated by a dissociation is mass analyzed, for performing an analysis of a molecular structure and composition of the target substance based on data collected by the mass spectrometer, comprising:

establishing preliminary information for a variety of ions generated in a dissociation process based on previously known information of the target substance, the preliminary information being a correspondence relationship between a specified mass and a composition formula derivable from the target substance;
checking whether or not a mass of a product ion obtained by an MSm (where m is an integer satisfying 2≦m≦n) analysis corresponds to the specified mass given by the preliminary information;
and
in a case where a result of the checking is positive, determining a composition formula of the product ion by using the preliminary information and then deducing a composition of the target substance.

1 more element

establishing preliminary information for a fragment desorbed in a dissociation process based on previously known information of the target substance, the preliminary information being a correspondence relationship between a specified mass and a composition formula derivable from the target substance;
checking whether or not a difference between a mass of a precursor ion of an MSm (where m is an integer satisfying 2≦m≦n) analysis and the specified mass of a product ion obtained by the analysis corresponds to a mass given by the preliminary information;
and
in a case where a result of the checking is positive, determining a composition formula of the product ion by using the preliminary information and then deducing a composition of the target substance.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 12/307,857Filed 21 Sep 2006
Published: US 2009/0309017 A117 Dec 2009
Granted: 27 Sep 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H01J 49/0027
Particle spectrometers or separator tubes: methods for using particle spectrometers
G01N 27/623
Ion mobility spectrometry: combined with mass spectrometry
H01J 49/0081
Combinations of spectrometers, tandem spectrometers, e.g. MS/MS, MSn: tandem in time, i.e. using a single spectrometer
H01J
Electric discharge tubes or discharge lamps