Patents by Inventor Edward W Sheehan
Edward W Sheehan 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: 8008617Abstract: Ions carried in a flowing gas stream are transferred to another gas stream of different composition or purity through an ion selective aperture communicating between the gas streams. The ion selective aperture is formed of a central layer which has an electrically conductive layer on each of its surfaces. One or more open channels extend through the central layer and surface layers allowing physical movement of ions therethrough under the urging and influence of an electric field created by imposing a voltage differential between the conductive surface layers of the ion selective aperture. The gas flow rates of the different gas streams may be independently varied to allow adjustment of ion concentration and flow rate to meet the needs of the ion destination. This device can control sample ion introduction into gas-phase ion detectors, such as ion mobility analyzers, differential mobility analyzers, mass spectrometers, and combinations thereof.Type: GrantFiled: December 29, 2008Date of Patent: August 30, 2011Assignee: Science Applications International CorporationInventors: John C. Berends, Jr., Timothy P. Karpetsky, Ross C. Willoughby, Edward W. Sheehan
-
Patent number: 7816646Abstract: Atmospheric pressure, intermediate pressure and vacuum laser desorption ionization methods and ion sources are configured to increase ionization efficiency and the efficiency of transmitting ions to a mass to charge analyzer or ion mobility analyzer. An electric field is applied in the region of a sample target to accumulate ions generated from a local ion source on a solid or liquid phase sample prior to applying a laser desorption pulse. The electric field is changed just prior to or during the desorption laser pulse to promote the desorption of charged species and improve the ionization efficiency of desorbed sample species. After a delay, the electric field may be further changed to optimize focusing and transmission of ions into a mass spectrometer or ion mobility analyzer.Type: GrantFiled: May 20, 2008Date of Patent: October 19, 2010Assignees: Chem-Space Associates, Inc., PerkinElmer Health Sciences, Inc.Inventors: Ross C. Willoughby, Edward W. Sheehan, Craig M. Whitehouse
-
Patent number: 7569812Abstract: An improved ion source and means for collecting and focusing dispersed gas-phase ions from a remote reagent chemical ionization source (R2CIS) at atmospheric or intermediate pressure is described. The R2CIS is under electronic control and can produce positive, negative, or positive and negative reagent ions simultaneously. This remote source of reagent ions is separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the R2CIS into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming sample ionic species. The resulting sample ionic species are then introduced into a mass spectrometer, ion mobility spectrometer or other sensor capable of detecting the sample ions.Type: GrantFiled: October 7, 2006Date of Patent: August 4, 2009Assignee: Science Applications International CorporationInventors: Timothy P. Karpetsky, John C. Berends, Jr., Edward W. Sheehan, Ross C. Willoughby
-
Patent number: 7375319Abstract: Atmospheric pressure, intermediate pressure and vacuum laser desorption ionization methods and ion sources are configured to increase ionization efficiency and the efficiency of transmitting ions to a mass to charge analyzer or ion mobility analyzer. An electric field is applied in the region of a sample target to accumulate ions generated from a local ion source on a solid or liquid phase sample prior to applying a laser desorption pulse. The electric field is changed just prior to or during the desorption laser pulse to promote the desorption of charged species and improve the ionization efficiency of desorbed sample species. After a delay, the electric field may be further changed to optimize focusing and transmission of ions into a mass spectrometer or ion mobility analyzer.Type: GrantFiled: August 7, 2006Date of Patent: May 20, 2008Inventors: Ross C. Willoughby, Edward W. Sheehan, Craig M. Whitehouse
-
Patent number: 7253406Abstract: An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at sub-atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a barrier, comprised of alternating laminates of metal and insulator, populated with a plurality of openings, wherein DC potentials are applied to each metal laminate necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to sub-atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermal-pneumatic ionization sources.Type: GrantFiled: July 24, 2006Date of Patent: August 7, 2007Assignee: Chem-Space Associates, IncorporatedInventors: Edward W Sheehan, Ross C Willoughby
-
Patent number: 7095019Abstract: An improved ion source and portable analyzer for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions generated by direct or alternating currents, separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer.Type: GrantFiled: May 2, 2005Date of Patent: August 22, 2006Assignee: Chem-Space Associates, Inc.Inventors: Edward W Sheehan, Ross C Willoughby
-
Patent number: 7087898Abstract: Atmospheric pressure, intermediate pressure and vacuum laser desorption ionization methods and ion sources are configured to increase ionization efficiency and the efficiency of transmitting ions to a mass to charge analyzer or ion mobility analyzer. An electric field is applied in the region of a sample target to accumulate ions generated from a local ion source on a solid or liquid phase sample prior to applying a laser desorption pulse. The electric field is changed just prior to or during the desorption laser pulse to promote the desorption of charged species and improve the ionization efficiency of desorbed sample species. After a delay, the electric field may be further changed to optimize focusing and transmission of ions into a mass spectrometer or ion mobility analyzer.Type: GrantFiled: June 7, 2004Date of Patent: August 8, 2006Inventors: Ross C. Willoughby, Edward W. Sheehan, Craig M. Whitehouse
-
Patent number: 6914243Abstract: Improvements have been made for collecting, focusing, and directing of ions and/or charged particles generated at atmospheric or near atmospheric pressure sources, such as but not limited to, electrospray; atmospheric pressure discharge ionization, chemical ionization, photoionization, and matrix assisted laser desorption ionization; and inductively coupled plasma ionization. A multiple-aperture laminated structure is place at the interface of two pressure regions. Electric fields geometries and strengths across the laminated structure and diameters of the apertures; all of which act to optimize the transfer of the ions from the higher pressure region into the lower pressure region while reducing the gas-load on the lower pressure region. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when coupled to atmospheric, near atmospheric, or higher pressure ionization sources by reducing the gas-load on the vacuum system.Type: GrantFiled: June 7, 2004Date of Patent: July 5, 2005Inventors: Edward W. Sheehan, Ross C. Willoughby
-
Patent number: 6888132Abstract: An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources.Type: GrantFiled: May 30, 2003Date of Patent: May 3, 2005Inventors: Edward W Sheehan, Ross C Willoughby
-
Publication number: 20040245458Abstract: Improvements have been made for collecting, focusing, and directing of ions and/or charged particles generated at atmospheric or near atmospheric pressure sources, such as but not limited to, electrospray; atmospheric pressure discharge ionization, chemical ionization, photoionization, and matrix assisted laser desorption ionization; and inductively coupled plasma ionization. A multiple-aperture laminated structure is place at the interface of two pressure regions. Electric fields geometries and strengths across the laminated structure and diameters of the apertures; all of which act to optimize the transfer of the ions from the higher pressure region into the lower pressure region while reducing the gas-load on the lower pressure region. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when coupled to atmospheric, near atmospheric, or higher pressure ionization sources by reducing the gas-load on the vacuum system.Type: ApplicationFiled: June 7, 2004Publication date: December 9, 2004Inventors: Edward W. Sheehan, Ross C. Willoughby
-
Patent number: 6818889Abstract: A thin laminated high transmission electro-optical lens populated with a plurality of apertures in communication with its laminates used to improve the collection, focusing, and selection of ions generated from atmospheric pressure sources, such as electrospray, atmospheric pressure chemical ionization, inductively coupled plasma, discharge, photoionization and atmospheric pressure matrix assisted laser desorption ionization. The laminated lens is made of alternating layers of electrically insulating and metal laminates. The geometry of the lens may be planar or shaped into various curve shapes, any of which act to optimize the direct current (DC) electric field geometries and strengths across the lens for transferring virtually all the ions from the ion source into an ion-focusing region. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when coupled to atmospheric pressure ionization sources.Type: GrantFiled: May 31, 2003Date of Patent: November 16, 2004Inventors: Edward W. Sheehan, Ross C Willoughby
-
Patent number: 6784424Abstract: The present invention relates to an apparatus and method for focusing, separating, and detecting gas-phase ions using the principles of quadrupole fields, substantially at or near atmospheric pressure. Ions are entrained in a concentric flow of gas and travel through a high-transmission element into a RF/DC quadrupole, through a second high-transmission element, and then impact on an ion detector, such as a faraday plate; or through an aperture with subsequent identification by a mass spectrometer. Ions with stable trajectories pass through the RF/DC quadrupole while ions with unstable trajectories drift off-axis collide with the rods and are lost. Embodiments of this invention are devices and methods for focusing, separating and detecting gas-phase ions without the need for a vacuum chamber when coupled to atmospheric ionization sources.Type: GrantFiled: May 25, 2002Date of Patent: August 31, 2004Inventors: Ross C Willoughby, Edward W Sheehan
-
Patent number: 6781117Abstract: An improved collison or reaction cell for collecting and focusing gas-phase ions in a mixture from an ion source or a mass analyzer into a gas-filled collision cell, inducing fragmentation or reaction of the ions by interaction with neutral or ionic gas-phase species, passing the resultant ionic products into another mass analyzer, determining the mass spectrum of the collision fragment ions to confirm the identity of the components in a mixture. The collision cell simultaneously provides collision gas confinements, precursor and product ion confinement, variability of collision energy, and variability of the DC drift field in the collision cell. Embodiments of this invention are methods and devices for improving the information content of chemical ionic species when coupled in tandem with mass analyzers.Type: GrantFiled: May 29, 2003Date of Patent: August 24, 2004Inventors: Ross C Willoughby, Edward W Sheehan
-
Patent number: 6744041Abstract: Improvements have been made for collection and focusing of ions generated from atmospheric pressure sources such as electrospray, atmospheric pressure chemical ionization, inductively coupled plasma, discharge, photoionization and atmospheric pressure matrix assisted laser desorption ionization. A high transmission electro-optical surface is placed between the source regions and the focusing regions to optimize the field geometries and strengths in each respective region. Compression ratios of greater than 5000 are capable of transferring virtually all ions from large volume dispersive ion regions into ion beam cross-sections of less than 1 mm. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when coupled to atmospheric pressure ionization sources.Type: GrantFiled: June 8, 2001Date of Patent: June 1, 2004Inventors: Edward W Sheehan, Ross C Willoughby
-
Publication number: 20020011560Abstract: Improvements have been made for collection and focusing of ions generated from atmospheric pressure sources such as electrospray, atmospheric pressure chemical ionization, inductively coupled plasma, discharge, photoionization and atmospheric pressure matrix assisted laser desorption ionization. A high transmission electro-optical surface is placed between the source regions and the focusing regions to optimize the field geometries and strengths in each respective region. Compression ratios of greater than 5000 are capable of transferring virtually all ions from large volume dispersive ion regions into ion beam cross-sections of less than 1 mm. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when coupled to atmospheric pressure ionization sources.Type: ApplicationFiled: June 8, 2001Publication date: January 31, 2002Inventors: Edward W. Sheehan, Ross C. Willoughby
-
Patent number: 6278111Abstract: An improved electrospray (ES) apparatus has a low pressure ES chamber coupled to a desolvation chamber. The desolvation chamber desolvates the incoming analyte ions of the cone-jet with non-conductive energy. The apparatus stabilizes cone-jet formation in the ES chamber. The apparatus receives solvated ions without pressure reduction, produces desolvated ions with non-conductive energy in a low pressure region, and outputs the desolvated ions towards a mass spectrometer as a substantially solvent-free ion beam suitable for mass spectrometer analysis. The apparatus avoids the degree of pressure reduction featured in prior ES techniques.Type: GrantFiled: November 12, 1998Date of Patent: August 21, 2001Assignee: Waters Investments LimitedInventors: Edward W. Sheehan, Ross C. Willoughby, Joseph A. Jarrell, David M. Strand
-
Patent number: 5838002Abstract: An electrospray ion production method and ion source designed to reduce overall gas load on the vacuum system and enhance the ion production and collection efficiencies. This ion source is for gas phase ion analysis of constituents dissolved in liquid solution comprising a needle (10) held at high electrical potential through which the solution flows into a first chamber (1) maintained at reduced pressure, forming a highly charged liquid cone-jet. The highly charged liquid jet is steered, in the first chamber, on-axis with an aperture into a second chamber (2) maintained at higher pressure than that of the first chamber. The second chamber is heated and pressurized to facilitate desolvation of the solution droplets originating from the breakup of the highly charged jet, resulting in the production of gas phase ions by the electrospray ionization process. The gas phase ions are then sampled and detected.Type: GrantFiled: August 21, 1996Date of Patent: November 17, 1998Assignee: Chem-Space Associates, IncInventor: Edward W. Sheehan