Removal of ions from survey scans using variable window band-pass filtering to improve intrascan dynamic range

Patent metadata

Field	Value
Publication number	US-9269555-B2
Application number	US-201214123184-A
Country	US
Kind code	B2
Filing date	May 30, 2012
Priority date	Jun 3, 2011
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

Systems and methods are used to band-pass filter ions from a mass range. A full spectrum is received for a full scan of a mass range using a tandem mass spectrometer. A mass selection window of the full spectrum is selected and a set of tuning parameter values is selected. The tandem mass spectrometer is instructed to perform a scan of the mass selection window using the set of tuning parameter values. A spectrum is received for the scan from the tandem mass spectrometer. A band-pass filtered spectrum is created for the mass range that includes values from the spectrum for the mass selection window of the mass range. Systems and methods are also used to band-pass filter ions from two or more mass selection windows across the mass range and to filter out ions from a mass selection window between two band-pass mass selection windows.

First claim

What is claimed is:

1. A system for band-pass filtering ions from a mass range, comprising:
a tandem mass spectrometer that includes a mass analyzer that can analyze precursor ions or fragment ions using different sets of tuning parameter values; and
a processor in communication with the tandem mass spectrometer that
instructs the tandem mass spectrometer to perform a precursor ion survey scan of a mass range, producing a full precursor ion spectrum for the mass range,
receives the full precursor ion spectrum from the tandem mass spectrometer,
from the full precursor ion spectrum, identifies for removal precursor ions that produce saturation in a detector sub-system of the mass analyzer,
across the mass range, selects non-overlapping precursor mass selection windows with variable window widths based on the precursor ions identified for removal, wherein each precursor mass selection window is selected either to include a precursor ion identified for removal and to prevent precursor ions from being fragmented or is selected to not include a precursor ion identified for removal and to allow precursor ions to be fragmented and allow resulting fragmented ions to be mass analyzed,
instructs the tandem mass spectrometer to fragment and analyze fragment ions of only precursor mass selection windows that are selected to not include a precursor ion identified for removal using a set of tuning parameter values for the detection sub-system, producing a plurality of fragment ion spectra, and
receives the plurality of fragment ion spectra from the tandem mass spectrometer and creates a band-pass filtered fragment ion spectrum from the plurality of fragment ion spectra.

2. The system of claim 1 , wherein the processor identifies for removal precursor ions that produce saturation in the detector sub-system by
identifying precursor ions in the full precursor ion spectrum that have an ion count rate that exceeds a total ion count rate of the detector sub-system.

3. The system of claim 1 , wherein the processor identifies for removal precursor ions that produce saturation in the detector sub-system by
identifying precursor ions in the full precursor ion spectrum that have an intensity that exceeds a threshold intensity of the detector sub-system.

4. The system of claim 1 , wherein the set of tuning parameter values comprise a maximum intensity value of the detection sub-system.

5. The system of claim 1 , wherein the set of tuning parameter values comprise a total ion current value of the detection sub-system.

6. The system of claim 1 , wherein the processor further instructs the tandem mass spectrometer to fragment the precursor mass selection windows that are selected to not include a precursor ion identified for removal using one or more different sets of tuning parameter values for the detection sub-system.

7. A method for band-pass filtering ions from a mass range, comprising:
receiving a full precursor ion spectrum from a tandem mass spectrometer that includes a mass analyzer that can analyze precursor ions or fragment ions using different sets of tuning parameter values, wherein the tandem mass spectrometer performs a precursor ion survey scan of a mass range to produce the full precursor ion spectrum for the mass range;
from the full precursor ion spectrum, identifying for removal precursor ions that produce saturation in a detector sub-system of the mass analyzer using a processor; and
across the mass range, selecting non-overlapping precursor mass selection windows with variable window widths based on the precursor ions identified for removal using the processor, wherein each precursor mass selection window is selected either to include a precursor ion identified for removal and to prevent precursor ions from being fragmented or is selected to not include a precursor ion identified for removal and to allow precursor ions to be fragmented and allow resulting fragmented ions to be mass analyzed;
instructing the tandem mass spectrometer to fragment and analyze fragment ions of only precursor mass selection windows that are selected to not include a precursor ion identified for removal using a set of tuning parameter values for the detection sub-system, producing a plurality of fragment ion spectra; and
receiving the plurality of fragment ion spectra from the tandem mass spectrometer and creating a band-pass filtered fragment ion spectrum from the plurality of fragment ion spectra using the processor.

8. The method of claim 7 , wherein the identifying steps comprises identifying precursor ions in the full precursor ion spectrum that have an ion count rate that exceeds a total ion count rate of the detector sub-system.

9. The method of claim 7 , wherein the identifying steps comprises identifying precursor ions in the full precursor ion spectrum that have an intensity that exceeds a threshold intensity of the detector sub-system.

10. The method of claim 7 , wherein the set of tuning parameter values comprise a maximum intensity value of the detection sub-system.

11. The method of claim 7 , wherein the set of tuning parameter values comprise a total ion current value of the detection sub-system.

12. The method of claim 7 , further comprising:
instructing the tandem mass spectrometer to fragment the precursor mass selection windows that are selected to not include a precursor ion identified for removal using one or more different sets of tuning parameter values for the detection sub-system using the processor.

13. 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 band-pass filtering ions from a mass range, the method comprising:
providing a system, wherein the system comprises one or more distinct software modules, and wherein the distinct software modules comprise a measurement module and a filtering module;
receiving a full precursor ion spectrum from a tandem mass spectrometer that includes a mass analyzer that can analyze precursor ions or fragment ions using different sets of tuning parameter values using the measurement module, wherein the tandem mass spectrometer performs a precursor ion survey scan of a mass range to produce the full precursor ion spectrum for the mass range;
from the full precursor ion spectrum, identifying for removal precursor ions that produce saturation in a detector sub-system of the mass analyzer using the filtering module;
across the mass range, selecting non-overlapping precursor mass selection windows with variable window widths based on the precursor ions identified for removal using the filtering module, wherein each precursor mass selection window is selected either to include a precursor ion identified for removal and to prevent precursor ions from being fragmented or is selected to not include a precursor ion identified for removal and to allow precursor ions to be fragmented and allow resulting fragmented ions to be mass analyzed;
instructing the tandem mass spectrometer to fragment and analyze fragment ions of only precursor mass selection windows that are selected to not include a precursor ion identified for removal using a set of tuning parameter values for the detection sub-system using the filtering module, producing a plurality of fragment ion spectra; and
receiving the plurality of fragment ion spectra from the tandem mass spectrometer and creating a band-pass filtered fragment ion spectrum from the plurality of fragment ion spectra using the filtering module.

14. The computer program product of claim 13 , wherein the identifying step comprises

Assignees

• Tate Stephen A
• Bloomfield Nic G
• Dh Technologies Dev Pte Ltd

Inventors

• Tate Stephen A
• Bloomfield Nic G

Classifications

• H01J49/0031 Primary

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

• H01J49/004

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

• H01J49/06 Primary

  Electron- or ion-optical arrangements · CPC title

• H01J9/00

  Apparatus or processes specially adapted for the manufacture {, installation, removal, maintenance} of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps · CPC title

• H01J49/429

  Scanning an electric parameter, e.g. voltage amplitude or frequency · CPC title