Patents by Inventor Naobumi Oi

Naobumi Oi 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: 4963254
    Abstract: A packing material for chromatographic use wherein an organosilane of formula (I): ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3, which may be the same or different, each represents an alkyl, alkoxy or hydroxyl group or a halogen atom, provided that at least one of them represents an alkoxy group or a halogen atom; X represents an --NHCO-- or --NH.sub.3.sup..+-. --OCO-- group; n is an integer of 2 to 4; and *C represents an asymmetric carbon atom, is grafted on an inorganic carrier having hydroxyl groups on the surface thereof as well as a method for the analysis of an enantiomer mixture using the same are disclosed.
    Type: Grant
    Filed: July 14, 1988
    Date of Patent: October 16, 1990
    Assignees: Sumitomo Chemical Company, Limited, Sumika Chemical Analysis Service
    Inventors: Naobumi Oi, Hajimu Kitahara, Tadashi Doi
  • Patent number: 4604207
    Abstract: A packing material for chromatographic use which comprises an inorganic carrier having hydroxyl groups at the surface thereof having grafted thereon an .alpha.-arylalkylamine derivative which is formed by bonding an optically active .alpha.-arylalkylamine and an aminoalkylsilane through a dibasic carboxylic acid, and a method for liquid chromatographic analysis of an enantiomer mixture using this packing material as a stationary phase. The packing material of the present invention can be easily produced by the usual chemical reaction, is chemically stable, and exhibits excellent effects in the separation of an enantiomer mixture of a compound having an --NH-- group, --CONH-- group, or an --OCO-- group bonded to an asymmetric carbon atom thereof.
    Type: Grant
    Filed: January 18, 1984
    Date of Patent: August 5, 1986
    Assignee: Sumitomo Chemical Co., Ltd.
    Inventors: Naobumi Oi, Tadashi Doi, Masayuki Nagase
  • Patent number: 4512898
    Abstract: A packing material for chromatographic use comprising an inorganic carrier having hydroxyl groups at the surface thereof having grafted thereon an organosilane derivative selected from the group consisting of a urea derivative obtained by reacting an optically active isocyanate with an aminoalkylsilane, an N-carbomoyl amino acid derivative obtained by reacting an optically active amino acid carbamoylated by isocyanate with an aminoalkylsilane and an O-carbamoyl hydroxy acid derivative obtained by reacting an optically active hydroxy acid carbamoylated by isocyanate with an aminoalkylsilane is disclosed. This packing material is useful as a packing material for liquid chromatography analysis which comprises separating and analyzing an enantiomer mixture of a compound having an --OH group, a --CONH-- group, ##STR1## a --COO-- group, an --NHCOO-- group, an --NHCONH-- group or ##STR2## bonded to an asymmetric carbon atom thereof.
    Type: Grant
    Filed: September 30, 1983
    Date of Patent: April 23, 1985
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Naobumi Oi, Hajimu Kitahara
  • Patent number: 4332591
    Abstract: An analytical method for the determination of the total nitrogen content in aqueous systems, which comprises passing an inert gas stream containing substantially no nitrogen and carbon dioxide through a reaction tube, which is packed with a decomposition catalyst and maintained at a temperature of 700.degree. to 1200.degree. C., a condenser and a moisture-absorbing tube in this order, injecting an aqueous test sample to be analyzed into the reaction tube, and sending the gaseous products coming out of the moisture-absorbing tube to a mass spectrometer to determine the nitrogen content, and an apparatus for carrying out such a method. By this method, it is possible to determine the total nitrogen content in nitrogen compounds contained in aqueous systems, rapidly, accurately and with a high sensitivity.
    Type: Grant
    Filed: December 29, 1978
    Date of Patent: June 1, 1982
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Naobumi Oi, Tadamasa Itoh, Yoshiaki Yasumasa
  • Patent number: 4140496
    Abstract: An optically active s-triazine derivative having at least two asymmetric carbon atoms of the general formula: ##STR1## wherein n is 2 to 3; and X and Y are the same or different and are each a member selected from the group consisting of the groups: ##STR2## WHEREIN M IS 1 TO 3; AND R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are the same or different and are each an alkyl having 1 to 12 carbon atoms, a cycloalkyl having 5 to 6 carbon atoms, phenyl or benzyl, and a gas chromatographic method for the resolution and analysis of the mixture of enantiomers having an --NH-- group linked to an asymmetric carbon atom, comprising using said derivative as an optically active stationary phase for the gas chromatography.
    Type: Grant
    Filed: April 29, 1977
    Date of Patent: February 20, 1979
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Naobumi Oi, Hiroshi Takeda, Hiroo Shimada
  • Patent number: 4104040
    Abstract: An s-triazine derivative with at least one asymmetric carbon atom of the general formula: ##STR1## wherein R.sub.1 and R.sub.2 are different and are each hydrogen, an alkyl, an aralkyl or phenyl; R.sub.3 is an alkyl, a cycloalkyl, an aralkyl or phenyl; and X and Y are the same or different: ##STR2## wherein R.sub.4, R.sub.5,R.sub.7, R.sub.8 and R.sub.9 are the same or different and are each hydrogen, an alkyl, a cycloalkyl, an aralkyl or phenyl; and R.sub.6 is an alkyl, a cycloalkyl, an aralkyl or phenyl, and a gas chromatographic method for the resolution and analysis of the mixture of enantiomers having an --NH-- group linked to an asymmetric carbon atom, or to an atom in .alpha.-position with respect to an asymmetric carbon atom, comprising using said derivative as an optically active stationary phase for the gas chromatography.
    Type: Grant
    Filed: January 21, 1977
    Date of Patent: August 1, 1978
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Naobumi Oi, Koichi Moriguchi, Mari Matsuda