Patents by Inventor Graeme C. McAlister

Graeme C. McAlister has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10804088
    Abstract: A mass spectrometry method comprises: generating ions; directing the ions through an ion optical component within a first chamber having a first vacuum pressure, the ion optical component maintained at a first electrical potential; transferring the ions through an ion guide within a second chamber having a second vacuum pressure less than the first vacuum pressure, the ion guide maintained at a second electrical potential, wherein a difference between the first and second potentials imparts kinetic energy that causes collision-induced ion fragmentation within the second chamber that removes adduct species; and transferring the ions into another ion guide within a third chamber having a third vacuum pressure less than the second vacuum pressure, the other ion guide maintained at a third electrical potential, wherein a difference between the third and second potentials reduces a portion of the imparted kinetic energy of the ions passing into the third chamber.
    Type: Grant
    Filed: May 30, 2019
    Date of Patent: October 13, 2020
    Assignee: Thermo Finnigan LLC
    Inventors: Michael P. Goodwin, Michael W. Senko, Graeme C. McAlister
  • Patent number: 10453662
    Abstract: A method and corresponding apparatus are disclosed for analysis of a peptide-containing sample. The sample is prepared by adding isotopically-labeled peptides corresponding to endogenous peptides of interest, and the prepared sample is analyzed by liquid chromatography-mass spectrometry (LCMS). Detection in a high-resolution, accurate mass (HRAM) MS1 spectrum of a precursor ion matching an isotopically-labeled peptide triggers acquisition of an MS/MS spectrum (preferably acquired in an ion trap or other fast mass analyzer) to determine if a product ion is present matching a characteristic product ion (e.g., the y1 ion) of the isotopically-labeled peptide. If the characteristic product ion is present, then a HRAM MS/MS spectrum is acquired for detection and quantitation of the corresponding endogenous peptide.
    Type: Grant
    Filed: April 13, 2018
    Date of Patent: October 22, 2019
    Assignee: Thermo Finnigan LLC
    Inventors: Graeme C. McAlister, Shannon Eliuk Dixon, Romain M. Huguet
  • Publication number: 20180233341
    Abstract: A method and corresponding apparatus are disclosed for analysis of a peptide-containing sample. The sample is prepared by adding isotopically-labeled peptides corresponding to endogenous peptides of interest, and the prepared sample is analyzed by liquid chromatography-mass spectrometry (LCMS). Detection in a high-resolution, accurate mass (HRAM) MS1 spectrum of a precursor ion matching an isotopically-labeled peptide triggers acquisition of an MS/MS spectrum (preferably acquired in an ion trap or other fast mass analyzer) to determine if a product ion is present matching a characteristic product ion (e.g., the y1 ion) of the isotopically-labeled peptide. If the characteristic product ion is present, then a HRAM MS/MS spectrum is acquired for detection and quantitation of the corresponding endogenous peptide.
    Type: Application
    Filed: April 13, 2018
    Publication date: August 16, 2018
    Inventors: Graeme C. McALISTER, Shannon Eliuk DIXON, Romain M. HUGUET
  • Patent number: 9960027
    Abstract: A method and corresponding apparatus are disclosed for analysis of a peptide-containing sample. The sample is prepared by adding isotopically-labeled peptides corresponding to endogenous peptides of interest, and the prepared sample is analyzed by liquid chromatography-mass spectrometry (LCMS). Detection in a high-resolution, accurate mass (HRAM) MS1 spectrum of a precursor ion matching an isotopically-labeled peptide triggers acquisition of an MS/MS spectrum (preferably acquired in an ion trap or other fast mass analyzer) to determine if a product ion is present matching a characteristic product ion (e.g., the y1 ion) of the isotopically-labeled peptide. If the characteristic product ion is present, then a HRAM MS/MS spectrum is acquired for detection and quantitation of the corresponding endogenous peptide.
    Type: Grant
    Filed: May 25, 2016
    Date of Patent: May 1, 2018
    Assignee: Thermo Finnigan LLC
    Inventors: Graeme C. McAlister, Shannon Eliuk Dixon, Romain M. Huguet
  • Patent number: 9929003
    Abstract: An ion source filter for use in the source region is disclosed. The ion source filter includes four rod electrodes having circular cross sections. The rod electrodes of the ion source filter are sized and positioned such that the ratio r/r0 of the rod radius to the inscribed circle radius is considerably reduced relative to conventional RF/DC mass filters. The reduced r/r0 geometry has been observed to lessen the diminishment of resolution with increasing pressure relative to prior art devices.
    Type: Grant
    Filed: May 24, 2016
    Date of Patent: March 27, 2018
    Assignee: THERMO FINNIGAN LLC
    Inventor: Graeme C. McAlister
  • Publication number: 20170345632
    Abstract: A method and corresponding apparatus are disclosed for analysis of a peptide-containing sample. The sample is prepared by adding isotopically-labeled peptides corresponding to endogenous peptides of interest, and the prepared sample is analyzed by liquid chromatography-mass spectrometry (LCMS). Detection in a high-resolution, accurate mass (HRAM) MS1 spectrum of a precursor ion matching an isotopically-labeled peptide triggers acquisition of an MS/MS spectrum (preferably acquired in an ion trap or other fast mass analyzer) to determine if a product ion is present matching a characteristic product ion (e.g., the y1 ion) of the isotopically-labeled peptide. If the characteristic product ion is present, then a HRAM MS/MS spectrum is acquired for detection and quantitation of the corresponding endogenous peptide.
    Type: Application
    Filed: May 25, 2016
    Publication date: November 30, 2017
    Inventors: Graeme C. McALISTER, Shannon Eliuk DIXON, Romain M. HUGUET
  • Publication number: 20160358765
    Abstract: An ion source filter for use in the source region is disclosed. The ion source filter includes four rod electrodes having circular cross sections. The rod electrodes of the ion source filter are sized and positioned such that the ratio r/r0 of the rod radius to the inscribed circle radius is considerably reduced relative to conventional RF/DC mass filters. The reduced r/r0 geometry has been observed to lessen the diminishment of resolution with increasing pressure relative to prior art devices.
    Type: Application
    Filed: May 24, 2016
    Publication date: December 8, 2016
    Inventor: Graeme C. McAlister
  • Patent number: 9478405
    Abstract: Described herein are methods and systems related to the use of the pre-existing ion injection pathway of a mass spectrometer to perform beam-type collision-activated dissociation, as well as other dissociation methods. The methods can be practiced using a wide range of mass spectrometer configurations and allows MSn experiments to be performed on very basic mass spectrometers, even those without secondary mass analyzers and/or collision cells. Following injection and selection of a particular ion type or population, that population can be fragmented via beam-type collision-activated dissociation (CAD), as well as other dissociation methods, using the pre-existing ion injection pathway or inlet of a mass spectrometer. For CAD applications, this is achieved by transmitting the ions back along the ion injection pathway with a high degree of kinetic energy. As the ions pass into the higher pressure regions located in or near the atmospheric pressure inlet, the ions are fragmented and then trapped.
    Type: Grant
    Filed: May 4, 2015
    Date of Patent: October 25, 2016
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Joshua J. Coon, Graeme C. McAlister
  • Publication number: 20160020081
    Abstract: Described herein are methods and systems related to the use of the pre-existing ion injection pathway of a mass spectrometer to perform beam-type collision-activated dissociation, as well as other dissociation methods. The methods can be practiced using a wide range of mass spectrometer configurations and allows MSn experiments to be performed on very basic mass spectrometers, even those without secondary mass analyzers and/or collision cells. Following injection and selection of a particular ion type or population, that population can be fragmented via beam-type collision-activated dissociation (CAD), as well as other dissociation methods, using the pre-existing ion injection pathway or inlet of a mass spectrometer. For CAD applications, this is achieved by transmitting the ions back along the ion injection pathway with a high degree of kinetic energy. As the ions pass into the higher pressure regions located in or near the atmospheric pressure inlet, the ions are fragmented and then trapped.
    Type: Application
    Filed: May 4, 2015
    Publication date: January 21, 2016
    Applicant: Wisconsin Alumni Research Foundation
    Inventors: Joshua J. COON, Graeme C. MCALISTER
  • Patent number: 9053916
    Abstract: Described herein are methods and systems related to the use of the pre-existing ion injection pathway of a mass spectrometer to perform beam-type collision-activated dissociation, as well as other dissociation methods. The methods can be practiced using a wide range of mass spectrometer configurations and allows MSn experiments to be performed on very basic mass spectrometers, even those without secondary mass analyzers and/or collision cells. Following injection and selection of a particular ion type or population, that population can be fragmented via beam-type collision-activated dissociation (CAD), as well as other dissociation methods, using the pre-existing ion injection pathway or inlet of a mass spectrometer. For CAD applications, this is achieved by transmitting the ions back along the ion injection pathway with a high degree of kinetic energy. As the ions pass into the higher pressure regions located in or near the atmospheric pressure inlet, the ions are fragmented and then trapped.
    Type: Grant
    Filed: March 5, 2014
    Date of Patent: June 9, 2015
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Joshua J. Coon, Graeme C. McAlister
  • Publication number: 20140246577
    Abstract: Described herein are methods and systems related to the use of the pre-existing ion injection pathway of a mass spectrometer to perform beam-type collision-activated dissociation, as well as other dissociation methods. The methods can be practiced using a wide range of mass spectrometer configurations and allows MSn experiments to be performed on very basic mass spectrometers, even those without secondary mass analyzers and/or collision cells. Following injection and selection of a particular ion type or population, that population can be fragmented via beam-type collision-activated dissociation (CAD), as well as other dissociation methods, using the pre-existing ion injection pathway or inlet of a mass spectrometer. For CAD applications, this is achieved by transmitting the ions back along the ion injection pathway with a high degree of kinetic energy. As the ions pass into the higher pressure regions located in or near the atmospheric pressure inlet, the ions are fragmented and then trapped.
    Type: Application
    Filed: March 5, 2014
    Publication date: September 4, 2014
    Inventors: Joshua J. COON, Graeme C. MCALISTER
  • Patent number: 8742333
    Abstract: Described herein are methods and systems related to the use of the pre-existing ion injection pathway of a mass spectrometer to perform beam-type collision-activated dissociation, as well as other dissociation methods. Following injection and selection of a particular ion type or population, that population can be fragmented using the pre-existing ion injection pathway or inlet of a mass spectrometer. This is achieved by transmitting the ions back along the ion injection pathway. As the ions pass into the higher pressure regions located in or near the atmospheric pressure inlet, the ions are fragmented and then trapped. Following fragmentation and trapping, the ions can either be re-injected into the primary ion selection device or sent on to a secondary mass analyzer.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: June 3, 2014
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Joshua J. Coon, Graeme C. McAlister
  • Publication number: 20120091330
    Abstract: Described herein are methods and systems related to the use of the pre-existing ion injection pathway of a mass spectrometer to perform beam-type collision-activated dissociation, as well as other dissociation methods. Following injection and selection of a particular ion type or population, that population can be fragmented using the pre-existing ion injection pathway or inlet of a mass spectrometer. This is achieved by transmitting the ions back along the ion injection pathway. As the ions pass into the higher pressure regions located in or near the atmospheric pressure inlet, the ions are fragmented and then trapped. Following fragmentation and trapping, the ions can either be re-injected into the primary ion selection device or sent on to a secondary mass analyzer.
    Type: Application
    Filed: September 16, 2011
    Publication date: April 19, 2012
    Inventors: Joshua J. Coon, Graeme C. McAlister