Patents by Inventor Nebojsa Avdalovic

Nebojsa Avdalovic 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: 6325976
    Abstract: An electrolyitic suppressor including (a) a suppressor bed of ion exchange resin, (b) an electrode chamber adjacent the suppressor, (c) a first electrode in the electrode chamber, (d) a barrier separating the suppressor bed from the first electrode chamber preventing significant liquid flow but permitting transport of ions only of the same charge as the suppressor bed resin, (e) a second electrode in electrical communication with the resin bed, and (f) a recycle conduit between the suppressor outlet port and said electrode chamber. The second electrode may be in contact with the ion exchange resin in the suppressor or located in second electrode chamber.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: December 4, 2001
    Assignee: Dionex Corporation
    Inventors: Hamish Small, Yan Liu, John M. Riviello, Nebojsa Avdalovic, Kannan Srinivasan
  • Patent number: 6316270
    Abstract: A method for generating high purity acid or base in an aqueous stream for use as an eluent for chromatography and, particularly, ion chromatography. For generating a base for anion chromatography, the aqueous stream is directed through a cation exchange bed having a first strongly acidic and a second weakly acidic portions. An electrical potential is applied to the bed. Cations on the bed electromigrate into the aqueous stream while hydroxide ions are electrolytically generated to form a base-containing eluent. Anions to be detected and the generated eluent flow through a chromatographic separator. The chromatographic effluent flows past a detector.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: November 13, 2001
    Assignee: Dionex Corporation
    Inventors: Hamish Small, Nebojsa Avdalovic, Yan Liu
  • Patent number: 6316271
    Abstract: A method for generating high purity acid or base in an aqueous stream for use in analysis. For generating a base for anion chromatography, the aqueous stream is directed through a cation exchange bed having strongly acid first and weakly acidic second portions. An electrical potential is applied to the bed. Cations on the bed electromigrate into the aqueous stream while hydroxide ions are electrolytically generated to form a base-containing eluent. Analytes to be detected and the generated eluent flow through a detector.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: November 13, 2001
    Assignee: Dionex Corporation
    Inventors: Hamish Small, Nebojsa Avdalovic, Yan Liu
  • Patent number: 6315954
    Abstract: An apparatus for generating high purity acid or base in an aqueous stream for use in analysis. For generating a base, the aqueous stream is directed through a cation exchange bed having first strongly acidic and second weakly acidic portions. An electrical potential is applied to the bed. Cations on the bed electromigrate into the aqueous stream while hydroxide ions are electrolytically generated to form a base-containing eluent. Analytes to be detected and the generated eluent flow through a detector.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: November 13, 2001
    Assignee: Dionex Corporation
    Inventors: Hamish Small, Nebojsa Avdalovic, Yan Liu
  • Patent number: 6225129
    Abstract: Method and apparatus for generating an acid or base, e.g. for chromatographic analysis of anions. For generating a base the method includes the steps of providing a cation source in a cation source reservoir, flowing an aqueous liquid stream through a base generation chamber separated from the cation source reservoir by a barrier (e.g. a charged membrane) substantially preventing liquid flow while providing a cation transport bridge, applying an electric potential between an anode cation source reservoir and a cathode in the base generation chamber to electrolytically generate hydroxide ions therein and to cause cations in the cation source reservoir to electromigrate and to be transported across the barrier toward the cathode to combine with the transported cations to form cation hydroxide, and removing the cation hydroxide in an aqueous liquid stream as an effluent from the first base generation chamber. Suitable cation sources include a salt solution, a cation hydroxide solution or cation exchange resin.
    Type: Grant
    Filed: February 2, 1998
    Date of Patent: May 1, 2001
    Assignee: Dionex Corporation
    Inventors: Yan Liu, Hamish Small, Nebojsa Avdalovic
  • Patent number: 6074541
    Abstract: A method of coating a solid support (e.g. a capillary or chromatography packing) to alter the properties of the support surface for separating components in a fluid stream. The method comprises (a) covalently binding a coupling agent (including functional groups capable of forming free radical sites under hydrogen abstraction conditions) to the support surface in a uniform layer, and (b) thereafter, contacting the bound coupling agent with a solution of preformed polymer comprising totally saturated carbon chain backbones including leaving groups, under hydrogen abstraction conditions of elevated temperature in the presence of a free radical catalyst to remove leaving groups from the carbon chains to form free radical carbon binding sites which covalently bond to the coupling agent layer and to crosslink at least some of the preformed polymer through the free radical carbon binding sites to form a dimensional polymer network coating on said solid support surface.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: June 13, 2000
    Assignee: Dionex Corporation
    Inventors: Kannan Srinivasan, Nebojsa Avdalovic, Christopher A. Pohl
  • Patent number: 6036921
    Abstract: An apparatus for generating high purity acid or base in an aqueous stream for use as an eluent for chromatography and, particularly, ion chromatography. For generating a base for anion chromatography, the aqueous stream is directed through a cation exchange bed. An electrical potential is applied to the bed. Cations on the bed electromigrate into the aqueous stream while hydroxide ions are electrolytically generated to form a base-containing eluent. Anions to be detected and the generated eluent flow through a chromatographic separator and a detector. In one embodiment, between separation and detection, the separated anion stream flows through a second cation exchange bed with no electrical potential applied. The second bed serves as a suppressor. After completion of the desired number of cycles, flow through the first and second cation exchange beds may be reversed by appropriate valving for the next sample stream.
    Type: Grant
    Filed: January 13, 1998
    Date of Patent: March 14, 2000
    Assignee: Dionex Corporation
    Inventors: Hamish Small, Nebojsa Avdalovic, Yan Liu
  • Patent number: 6027643
    Abstract: Disclosed is a method and apparatus for electrolytically generating an acid or base eluent in an aqueous solution and for simultaneously suppressing conductivity of the eluent in an ion exchange bed after chromatographic separation in an ion chromatography system.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: February 22, 2000
    Assignee: Dionex Corporation
    Inventors: Hamish Small, John M. Riviello, Yan Liu, Nebojsa Avdalovic
  • Patent number: 5552580
    Abstract: A heated cover for a receptacle containing a vaporizable substance. The cover is heated to a temperature above the temperature of the substance so as to prevent condensation of vapor evaporated from the substance. A device for placing and removing the cover with respect to the receptacle is designed in connection with a temperature-controlled heating/cooling plate which controls the temperature of the contents of the receptacle.
    Type: Grant
    Filed: November 20, 1991
    Date of Patent: September 3, 1996
    Assignee: Beckman Instruments, Inc.
    Inventors: Robert F. Pfost, Nebojsa Avdalovic
  • Patent number: 5496517
    Abstract: A heated cover for a receptacle containing a vaporizable substance. The cover is heated to a temperature above the temperature of the substance so as to prevent condensation of vapor evaporated from the substance. A device for placing and removing the cover with respect to the receptacle is designed in connection with a temperature-controlled heating/cooling plate which controls the temperature of the contents of the receptacle.
    Type: Grant
    Filed: November 20, 1991
    Date of Patent: March 5, 1996
    Assignee: Beckman Instruments, Inc.
    Inventors: Robert F. Pfost, Nebojsa Avdalovic
  • Patent number: 5472584
    Abstract: Apparatus and methods are provided for increasing the sensitivity of detection of ionic species separated by capillary electrophoresis. The apparatus includes capillary electrophoretic separating means, suppressor means and detector means.
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: December 5, 1995
    Assignee: The Dow Chemical Company
    Inventors: Roy D. Rocklin, Christopher A. Pohl, John Stillian, Nebojsa Avdalovic