Patents by Inventor Gordon Lethbridge

Gordon Lethbridge 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).

  • Contamination text
    Patent number: 5834655
    Abstract: A method for testing petroleum hydrocarbon contamination in which method a sample is mixed with an alkyl halide extraction solvent. Subsequently the solvent extraction phase is separated, and a Friedel-Crafts Lewis acid catalyst is added thereby obtaining a colored reaction product in the solvent extraction phase, the color of which being indicative of the petroleum hydrocarbon contamination.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: November 10, 1998
    Assignee: Shell oil Company
    Inventors: Devji Dalubhai Lad, Gordon Lethbridge, Paul Eric Linnett