Patents by Inventor Kuniaki Tokuda

Kuniaki Tokuda 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).

  • Method for measuring bilirubin
    Patent number: 5563072
    Abstract: Direct bilirubin can be measured stably with high reliability by using bilirubin oxidase or a chemical oxidizing agent of manganese (III) ions, ferricyanide ions or copper ions, or direct bilirubin can also be measured by using as a reaction inhibitor a water-soluble high polymer or a nonionic surfactant having a HLB value of 15 or more.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: October 8, 1996
    Assignee: Wako Pure Chemical Industries, Ltd.
    Inventors: Kuniaki Tokuda, Kazuhito Tanimoto
  • Method for measuring bilirubin
    Patent number: 5449623
    Abstract: Total or direct bilirubin can be measured stably with high reliability by using as an oxidizing agent vanadic acid ions or manganese (III) ions, or direct bilirubin can also be measured by using as a reaction inhibitor a water-soluble high polymer or a nonionic surfactant having a HLB value of 15 or more.
    Type: Grant
    Filed: September 23, 1994
    Date of Patent: September 12, 1995
    Assignee: Wako Pure Chemical Industries, Ltd.
    Inventors: Kuniaki Tokuda, Kazuhito Tanimoto
  • Use of phenol derivative in colorimetric analysis of metal ions
    Patent number: 5376552
    Abstract: A phenol derivative obtained by reacting a carboxylic acid anhydride with a phenol compound, followed by condensation with iminodiacetic acid and formaldehyde, or a salt thereof is effective as an agent for adjusting color forming sensitivity in a colorimetric analysis of metal ions in a fluid such as a living body fluid.
    Type: Grant
    Filed: November 2, 1992
    Date of Patent: December 27, 1994
    Assignee: Wako Pure Chemical Industries, Ltd.
    Inventors: Kuniaki Tokuda, Taeko Soma, Naoki Teno
  • Colorimetrically measuring method of zinc
    Patent number: 5221626
    Abstract: A method for the colorimetic determination of zinc including the steps of:a) preparing a coloring reagent for zinc including1) an aqueous soluble 2-pyridylazoaminophenol derivative or a salt of a 2-pyridylazoaminophenol derivative, represented by the following formula (I): ##STR1## wherein 2 ) at least one surface active agent3) a masking agent for a metal,b) adding the coloring reagent solution to a sample solution containing zinc andc) measuring the absorbance of the solution at 555 nm.
    Type: Grant
    Filed: September 26, 1990
    Date of Patent: June 22, 1993
    Assignee: Wako Pure Chemical Industries Ltd.
    Inventors: Fujio Yamazato, Kuniaki Tokuda
  • Process for determination of .gamma.-GTP activity
    Patent number: 4879221
    Abstract: .gamma.-GTP activity can be determined easily by using a stabilized substrate solution comprising .gamma.-L-glutamyl-p-nitroanilide and a modified cyclodextrin, together with an acceptor solution containing an acceptor for glutamic acid and measuring p-nitroaniline generated.
    Type: Grant
    Filed: September 2, 1986
    Date of Patent: November 7, 1989
    Assignee: Wako Pure Chemical Industries, Ltd.
    Inventors: Kuniaki Tokuda, Seiji Morii, Kazuhiko Yamanishi
  • .gamma.-L-glutamyl-4-nitroanilide derivatives and process for determining .gamma.-GTP activity using the same
    Patent number: 4851572
    Abstract: A .gamma.-L-glutamyl-4-nitroanilide derivative of the formula: ##STR1## wherein R is a lower hydroxyalkyl group, is suitable as a substrate for determining .gamma.-GTP activity.
    Type: Grant
    Filed: July 1, 1988
    Date of Patent: July 25, 1989
    Assignee: Wako Pure Chemical Industries, Ltd.
    Inventors: Hiroshi Ogata, Hiroyoshi Nawa, Kuniaki Tokuda, Masami Ishihara
  • Reagent mixture for measuring magnesium
    Patent number: 4503156
    Abstract: A reagent mixture for measuring magnesium comprising Xylylazo Violet I or II as a color producing agent and at least one of sulfide compounds and thioureide compounds, and if necessary one or more surface active agents, can be stored for a long period of time stably and can give a stable color development.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: March 5, 1985
    Assignee: Wako Pure Chemical Industries, Ltd.
    Inventors: Fujio Yamazato, Kuniaki Tokuda, Toshihiko Oda
  • Method for measuring peroxidic substances
    Patent number: 4295853
    Abstract: Peroxidic substances in a sample, e.g. one or more peroxidic substances in fats and oils or in an organic material, lipoperoxides in a living sample, etc. can be determined, directly in a sample or after extracting the lipoperoxides from a living sample with a solvent, by contacting the peroxidic substances with an oxidizable color reagent in the presence of a metallic compound produced from a metal which is able to have two or more valences to produce color, and measuring degree of coloring colorimetrically.
    Type: Grant
    Filed: December 29, 1978
    Date of Patent: October 20, 1981
    Assignee: Wako Pure Chemical Industries, Ltd.
    Inventors: Shizuka Kasahara, Kazuhiko Yamanishi, Toshiro Hanada, Kuniaki Tokuda, Shinzo Kobatake
  • Determination of hydrogen peroxide
    Patent number: 4251629
    Abstract: Colorimetrical determination of hydrogen peroxide in clinical examinations, food additives analyses and general analyses can be carried out accurately, rapidly and economically by using a composition for producing color producing reagents comprising 4-aminoantipyrine, a N-substituted-3-alkylaniline and a hydrogen peroxide activating agent such as peroxidase, said composition forming a coloring material having excellent sensitivity and color stability in contact with hydrogen peroxide.
    Type: Grant
    Filed: July 28, 1978
    Date of Patent: February 17, 1981
    Assignee: Wako Pure Chemical Industries, Ltd.
    Inventors: Kazuhiko Yamanisi, Kuniaki Tokuda, Tosiro Hanada