Systems and methods for using variable mass selection window widths in tandem mass spectrometry

Patent metadata

Field	Value
Publication number	US-9460900-B2
Application number	US-201514835823-A
Country	US
Kind code	B2
Filing date	Aug 26, 2015
Priority date	Sep 8, 2010
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Systems and methods are used to analyze a sample using variable mass selection window widths. A tandem mass spectrometer is instructed to perform at least two fragmentation scans of a sample with different mass selection window widths using a processor. The tandem mass spectrometer includes a mass analyzer that allows variable mass selection window widths. The selection of the different mass selection window widths can be based on one or more properties of sample compounds. The properties may include a sample compound molecular weight distribution that is calculated from a molecular weight distribution of expected compounds or is determined from a list of molecular weights for one or more known compounds. The tandem mass spectrometer can also be instructed to perform an analysis of the sample before instructing the tandem mass spectrometer to perform the at least two fragmentation scans of the sample.

First claim

What is claimed is:

1. A system for analyzing a sample using variable precursor mass selection window widths, comprising:
a tandem mass spectrometer that includes a mass analyzer that allows fragmentation scans to be performed with variable precursor mass selection window widths across a mass range of a sample; and
a processor in communication with the tandem mass spectrometer that selects at least two variable precursor mass selection windows with different precursor mass selection window widths across the mass range of the sample and that instructs the tandem mass spectrometer to perform at least two fragmentation scans of the at least two variable precursor mass selection windows in a single scan of the mass range, wherein the value of the different precursor mass selection window widths chosen for a portion of the mass range is based on information known about the sample.

2. The system of claim 1 , wherein the processor further instructs the tandem mass spectrometer to adjust one or more different acquisition parameters for each different precursor mass selection window.

3. The system of claim 2 , wherein the acquisition parameters comprise one or more of an accumulation time, a collision energy, or a collision energy spread.

4. The system of claim 1 , wherein the at least two variable precursor mass selection windows are selected to contain the same number of mass values.

5. The system of claim 1 , wherein the at least two variable precursor mass selection windows are selected based on one or more properties of sample compounds.

6. The system of claim 5 , wherein the one or more properties of sample compounds comprise a sample compound molecular weight distribution.

7. The system of claim 1 , wherein the value of the different precursor mass selection window widths is adjusted across the mass range based on the known complexity of the sample, wherein where the sample is more complex or has a large number of ions, a narrower precursor mass selection window of the at least two variable precursor mass selection windows is selected, and where the sample is less complex or has a sparse number of ions, a wider precursor mass selection window of the at least two variable precursor mass selection windows is selected.

8. The system of claim 1 , wherein the value of the different precursor mass selection window widths is adjusted across the mass range to avoid known intense peaks.

9. The system of claim 6 , wherein the processor instructs the tandem mass spectrometer to perform an analysis of the sample before the processor instructs the tandem mass spectrometer to perform the at least two fragmentation scans of the sample that are part of a subsequent analysis of the sample.

10. The system of claim 9 , wherein the processor receives data produced by the analysis from the tandem mass spectrometer and calculates the sample compound molecular weight distribution from the data.

11. The system of claim 10 , wherein the processor calculates the sample compound molecular weight distribution by obtaining a spectrum from the data and calculating the sample compound molecular weight distribution from the spectrum.

12. The system of claim 9 , wherein the processor receives data produced by the analysis from the tandem mass spectrometer, interprets the data, and determines the sample compound molecular weight distribution from a pre-calculated compound molecular weight distribution found from the interpretation of data.

13. The system of claim 9 , wherein the processor instructs the tandem mass spectrometer to perform the analysis and the subsequent analysis two or more times in a looped manner in real-time.

14. The system of claim 1 , wherein a narrower precursor mass selection window of the at least two variable precursor mass selection windows is selected for an area of the mass range where compounds are known to exist, to improve the specificity of the known compounds.

15. The system of claim 1 , wherein a wider precursor mass selection window of the at least two variable precursor mass selection windows is selected for an area of the mass range where no compounds are known to exist or where there are few compounds of interest, to improve the sensitivity of the scan.

16. A method for analyzing a sample using variable precursor mass selection window widths, comprising:
selecting at least two variable precursor mass selection windows with different precursor mass selection window widths across the mass range of a sample, wherein the value of the different precursor mass selection window widths chosen for a portion of the mass range is based on information known about the sample; and
instructing a tandem mass spectrometer to perform at least two fragmentation scans of the at least two variable precursor mass selection windows in a single scan of the mass range using a processor, wherein the tandem mass spectrometer includes a mass analyzer that allows fragmentation scans to be performed with variable precursor mass selection window widths.

17. The method of claim 16 , wherein the selecting step comprises selecting a narrower precursor mass selection window of the at least two variable precursor mass selection windows for an area of the mass range where compounds are known to exist, to improve the specificity of the known compounds.

18. The method of claim 16 , wherein the selecting step comprises selecting a wider precursor mass selection window of the at least two variable precursor mass selection windows for an area of the mass range where no compounds are known to exist or where there are few compounds of interest, to improve the sensitivity of the scan.

19. A computer program product, comprising a tangible computer-readable storage medium whose contents include a program with instructions being executed on a processor so as to perform a method for analyzing a sample using variable precursor mass selection window widths, the method comprising:
providing a system, wherein the system comprises one or more distinct software modules, and wherein the distinct software modules comprise a mass selection window width module;
selecting at least two variable precursor mass selection windows with different precursor mass selection window widths across the mass range of a sample, wherein the value of the different precursor mass selection window widths chosen for a portion of the mass range is based on information known about the sample; and
instructing a tandem mass spectrometer to perform at least two fragmentation scans of the at least two variable precursor mass selection windows in a single scan of the mass range using the mass selection window width module, wherein the tandem mass spectrometer includes a mass analyzer that allows fragmentation scans to be performed with variable precursor mass selection window widths.

Assignees

• Dh Technologies Dev Pte Ltd

Inventors

• Bonner Ronald F
• Tate Stephen A

Classifications

• H01J49/0031 Primary

  Step by step routines describing the use of the apparatus (H01J49/0081 takes precedence) · CPC title

• H01J49/0081

  Tandem in time, i.e. using a single spectrometer · CPC title

• H01J49/0027 Primary

  Methods for using particle spectrometers · CPC title

• H01J49/004

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

• H01J49/0045

  characterised by the fragmentation or other specific reaction · CPC title