Patents by Inventor S. M. Rahmat Ullah

S. M. Rahmat Ullah 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: 9739692
    Abstract: Apparatus for extracting organic analytes from a sample comprising a first compressed gas source connected to valving and a sample extraction cell connected to the valving. A pressure regulator is connected to the extraction cell outlet to the pressure regulator. The pressure regulator blocks fluid flow when the pressure at the pressure regulator inlet is below a predetermined pressure and permits fluid flow when above said predetermined pressure. The apparatus is free of operative association with a mechanical pump or with a compressed gas source other than the compressed gas source. An extraction method for using the above apparatus is described.
    Type: Grant
    Filed: March 27, 2015
    Date of Patent: August 22, 2017
    Assignee: Dionex Corporation
    Inventors: Kannan Srinivasan, S M Rahmat Ullah
  • Patent number: 9733170
    Abstract: A method of extracting an analyte from a sample is described where the sample includes water. The sample and polymeric drying agent are added to a container. The polymeric drying agent includes a cationic monomer, an anionic monomer, and a crosslinker. The polymeric drying agent is configured to sorb water from the sample.
    Type: Grant
    Filed: September 8, 2016
    Date of Patent: August 15, 2017
    Assignee: Dionex Corporation
    Inventors: Christopher A. Pohl, Kannan Srinivasan, S M Rahmat Ullah
  • Patent number: 9459184
    Abstract: A method of extracting an analyte from a sample is described where the sample includes water. The sample and polymeric drying agent are added to a container. The polymeric drying agent includes a cationic monomer, an anionic monomer, and a crosslinker. The polymeric drying agent is configured to sorb water from the sample.
    Type: Grant
    Filed: March 8, 2012
    Date of Patent: October 4, 2016
    Assignee: DIONEX CORPORATION
    Inventors: Christopher A. Pohl, Kannan Srinivasan, S M Rahmat Ullah
  • Patent number: 8507292
    Abstract: A method for pretreating and extracting a liquid sample by sorbing an aqueous liquid sample, including an organic analyte and an acid or a base, in a solid sorbent material, and at least partially neutralizing the acid or base by reaction with neutralizing ions retained on a support surface, and contacting the liquid sample-sorbed sorbent material at elevated temperature and pressure with an organic solvent to extract the analyte into said solvent, preferably in a vessel having an extraction chamber with a zirconium metal interior surface.
    Type: Grant
    Filed: July 1, 2011
    Date of Patent: August 13, 2013
    Assignee: Dionex Corporation
    Inventors: Kannan Srinivasan, Bruce Richter, Christopher A. Pohl, Brett Murphy, Brian Dorich, S. M. Rahmat Ullah
  • Publication number: 20120028368
    Abstract: A method for pretreating and extracting a liquid sample by sorbing an aqueous liquid sample, including an organic analyte and an acid or a base, in a solid sorbent material, and at least partially neutralizing the acid or base by reaction with neutralizing ions retained on a support surface, and contacting the liquid sample-sorbed sorbent material at elevated temperature and pressure with an organic solvent to extract the analyte into said solvent, preferably in a vessel having an extraction chamber with a zirconium metal interior surface.
    Type: Application
    Filed: July 1, 2011
    Publication date: February 2, 2012
    Applicant: Dionex Corporation
    Inventors: Kannan Srinivasan, Bruce Richter, Christopher A. Pohl, Brett Murphy, Brian Dorich, S.M. Rahmat Ullah
  • Publication number: 20090221079
    Abstract: A method for pretreating and extracting a liquid sample by sorbing an aqueous liquid sample, including an organic analyte and an acid or a base, in a solid sorbent material, and at least partially neutralizing the acid or base by reaction with neutralizing ions retained on a support surface, and contacting the liquid sample-sorbed sorbent material at elevated temperature and pressure with an organic solvent to extract the analyte into said solvent, preferably in a vessel having an extraction chamber with a zirconium metal interior surface.
    Type: Application
    Filed: February 28, 2008
    Publication date: September 3, 2009
    Applicant: DIONEX CORPORATION
    Inventors: Kannan Srinivasan, Bruce Richter, Christopher A. Pohl, Brett Murphy, Brian Dorich, S.M. Rahmat Ullah
  • Publication number: 20080223787
    Abstract: In a liquid chromatographic system, removing at least part of a volatile component from the liquid sample stream after separation by flowing it through a volatile component-removal device including a porous wall having a surface coating of a permeable polymer less than 10 ?m thick. A liquid chromatographic system suitable for performing the method. Also, a liquid chromatographic system in which volatile component is removed prior to separation across the same type of membrane or across a membrane made of a copolymer of perfluoro-2,2-dimethyl-1,3-dioxole.
    Type: Application
    Filed: October 30, 2007
    Publication date: September 18, 2008
    Applicant: Dionex Corporation
    Inventors: Purnendu K. Dasgupta, S.M. Rahmat Ullah, Kannan Srinivasan
  • Patent number: 7306720
    Abstract: In a liquid chromatographic system, removing at least part of a volatile component from the liquid sample stream after separation by flowing it through a volatile component-removal device including a porous wall having a surface coating of a permeable polymer less than 10 ?m thick. A liquid chromatographic system suitable for performing the method. Also, a liquid chromatographic system in which volatile component is removed prior to separation across the same type of membrane or across a membrane made of a copolymer of perfluoro-2,2-dimethyl-1,3-dioxole.
    Type: Grant
    Filed: August 23, 2004
    Date of Patent: December 11, 2007
    Assignee: Dionex Corporation
    Inventors: Purnendu K. Dasgupta, S. M. Rahmat Ullah, Kannan Srinivasan