Patents by Inventor Helmut Feuerstein

Helmut Feuerstein 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).

  • Stabilized composition of tetrazolium salts
    Patent number: 4847196
    Abstract: The present invention provides stabilized compositions of tetrazolium salts for analytical purposes which contain 1 to 10 moles of a complex forming acid which is soluble in polar solvents, per mole of tetrazolium salt. Additionally, the invention provides a process for the detection of reducing materials, wherein a stabilized composition as described is added to a test batch.
    Type: Grant
    Filed: January 19, 1988
    Date of Patent: July 11, 1989
    Assignee: Boehringer Mannheim GmbH
    Inventors: Edda Geisler, Helmut Feuerstein, Hans Lange
  • Stabilized composition of tetrazolium salts
    Patent number: 4613569
    Abstract: The present invention provides stabilized compositions of tetrazolium salts for analytical purposes, wherein they contain 1 to 10 moles of a complex-forming acid which is soluble in polar solvents per mole of tetrazolium salt.The present invention also provides a process for the detection of reducing materials, wherein one of the above stabilized compositions is added to a test batch.
    Type: Grant
    Filed: March 27, 1984
    Date of Patent: September 23, 1986
    Assignee: Boehringer Mannheim GmbH
    Inventors: Edda Geisler, Helmut Feuerstein, Hans Lange