Patents by Inventor Keqi Tang

Keqi Tang 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: 6818890
    Abstract: A method and apparatus enabling increased sensitivity in ion mobility spectrometry/mass spectrometry instruments which substantially reduces or eliminates the loss of ions in ion mobility spectrometer drift tubes utilizing an hourglass electrodynamic ion funnel at the entrance to the drift tube and/or an internal ion funnel at the exit of the drift tube. An hourglass electrodynamic funnel is formed of at least an entry element, a center element, and an exit element, wherein the aperture of the center element is smaller than the aperture of the entry element and the aperture of the exit elements. Ions generated in a relatively high pressure region by an ion source at the exterior of the hourglass electrodynamic funnel are transmitted to a relatively low pressure region at the entrance of the hourglass funnel through a conductance limiting orifice.
    Type: Grant
    Filed: October 30, 2003
    Date of Patent: November 16, 2004
    Assignee: Battelle Memorial Institute
    Inventors: Richard D. Smith, Keqi Tang, Alexandre A. Shvartsburg
  • Publication number: 20040188605
    Abstract: A method for introducing ions generated in a region of relatively high pressure into a region of relatively low pressure by providing at least two electrospray ion sources, providing at least two capillary inlets configured to direct ions generated by the electrospray sources into and through each of the capillary inlets, providing at least two sets of primary elements having apertures, each set of elements having a receiving end and an emitting end, the primary sets of elements configured to receive a ions from the capillary inlets at the receiving ends, and providing a secondary set of elements having apertures having a receiving end and an emitting end, the secondary set of elements configured to receive said ions from the emitting end of the primary sets of elements and emit said ions from said emitting end of the secondary set of elements.
    Type: Application
    Filed: March 25, 2003
    Publication date: September 30, 2004
    Inventors: Keqi Tang, Mikhail B. Belov, Aleksey V. Tolmachev, Harold R. Udseth, Richard D. Smith
  • Patent number: 6667474
    Abstract: The present invention relates to a heated capillary assembly which connects an atmospheric pressure ionization source to a lower pressure mass analyzing system which comprises a capillary tube removably secured to, and extending through the bore of a capillary support assembly.
    Type: Grant
    Filed: October 27, 2000
    Date of Patent: December 23, 2003
    Assignee: Thermo Finnigan LLC
    Inventors: Jeffrey B. Abramson, Nigel P. Gore, Mukul Khosla, Iain C. Mylchreest, Keqi Tang, Eric B. Johnson
  • Publication number: 20030168591
    Abstract: A method and apparatus that utilizes two or more emitters simultaneously to form an electrospray of a sample that is then directed into a mass spectrometer, thereby increasing the total ion current introduced into an electrospray ionization mass spectrometer, given a liquid flow rate of a sample. The method and apparatus are most conveniently constructed as an array of spray emitters fabricated on a single chip, however, the present invention encompasses any apparatus wherein two or more emitters are simultaneously utilized to form an electrospray of a sample that is then directed into a mass spectrometer.
    Type: Application
    Filed: March 5, 2002
    Publication date: September 11, 2003
    Inventors: Richard D. Smith, Keqi Tang, Yuehe Lin
  • Patent number: 6583408
    Abstract: A jet disturber used in combination with an ion funnel to focus ions and other charged particles generated at or near atmospheric pressure into a relatively low pressure region, which allows increased conductance of the ions and other charged particles. The jet disturber is positioned within an ion funnel and may be interfaced with a multi-capillary inlet juxtaposed between an ion source and the interior of an instrument maintained at near atmospheric pressure. The invention finds particular advantages when deployed to improve the ion transmission between an electrospray ionization source and the first vacuum stage of a mass spectrometer.
    Type: Grant
    Filed: May 18, 2001
    Date of Patent: June 24, 2003
    Assignee: Battelle Memorial Institute
    Inventors: Richard D. Smith, Taeman Kim, Keqi Tang, Harold R. Udseth
  • Patent number: 6528784
    Abstract: There is described an interface for delivering ions generated in an ion source into a mass analyzer in a chamber under vacuum pressure. In particular, the interface employs two consecutive ion guides operated to dissociate adduct ions formed in the ion source or high pressure regions of the interface between the ion source and the mass analyzer, thus improving the limit of detection or limit of quantitation of the mass analyzer by increasing the analyte ion current.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: March 4, 2003
    Inventors: Keqi Tang, Alan E. Schoen, Jean-Jacques Dunyach
  • Publication number: 20020185606
    Abstract: A jet disturber used in combination with an ion funnel to focus ions and other charged particles generated at or near atmospheric pressure into a relatively low pressure region, which allows increased conductance of the ions and other charged particles. The jet disturber is positioned within an ion funnel and may be interfaced with a multi-capillary inlet juxtaposed between an ion source and the interior of an instrument maintained at near atmospheric pressure. The invention finds particular advantages when deployed to improve the ion transmission between an electrospray ionization source and the first vacuum stage of a mass spectrometer.
    Type: Application
    Filed: May 18, 2001
    Publication date: December 12, 2002
    Inventors: Richard D. Smith, Taeman Kim, Keqi Tang, Harold R. Udseth
  • Patent number: 5873523
    Abstract: An electrospray apparatus incorporating the invention includes a capillary with an exit for ejecting a fluid, and an electrode positioned downstream from the exit. A gas source is used to establish a region of gas, at least immediately about the exit. A voltage supply creates a potential difference between the capillary exit and the electrode, the potential difference being sufficient to both establish a cone jet mode of operation at the exit of the capillary, to ionize the region of gas about the exit and create a current flow between the exit and the electrode. The current flow exhibits an increased value upon the gas becoming ionized, thus enabling detection of the establishment of a corona. This action creates a corona-assisted cone jet mode of electrospray operation which enables the fluid to disperse into highly uniform sized particles. The preferred gas is carbon dioxide.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: February 23, 1999
    Assignee: Yale University
    Inventors: Alessandro Gomez, Juan Fernandez de la Mora, Keqi Tang