Patents by Inventor Takefumi Yokokura
Takefumi Yokokura 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).
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Patent number: 8496819Abstract: Both a column having high-pressure resistance and capable of performing high-speed separation and analysis even with a small flow rate and a liquid chromatograph apparatus using the column are provided. A separation column according to the present invention has a monolithic rod being arranged in the center, being made of a porous material, and having a circular cross section, a filler layer arranged such that it encircles a circumferential surface of the monolithic rod, and a cylindrical support medium arranged outside the filler layer. The filler layer is formed by filling a tube-like gap between the monolithic rod and the support medium with particles or beads.Type: GrantFiled: June 26, 2008Date of Patent: July 30, 2013Assignee: Hitachi High-Technologies CorporationInventors: Katsutoshi Shimizu, Masahito Ito, Kimihiko Ishii, Yoshihiro Nagaoka, Kisaburo Deguchi, Takefumi Yokokura
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Patent number: 8319194Abstract: The mass spectrometer includes an ion source; a mass spectrometry part; a sample container; a heater for the sample container; a first gas tube connected to the sample container to introduce a gas into the sample container; and a second gas tube connected to the sample container to transfer a headspace gas of the sample container to the ion source, in which the ion source generates ions of the headspace gas and the mass spectrometry part performs mass spectrometry of the ions. Thereby, the mass spectrometer as a drug detection equipment can analyze various drugs in urine rapidly and with high sensitivity.Type: GrantFiled: August 22, 2011Date of Patent: November 27, 2012Assignee: Hitachi High-Technologies CorporationInventors: Makoto Hashimoto, Takefumi Yokokura, Masuyoshi Yamada, Hiroyuki Inoue, Hidetoshi Morokuma
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Publication number: 20120049055Abstract: The mass spectrometer includes an ion source; a mass spectrometry part; a sample container; a heater for the sample container; a first gas tube connected to the sample container to introduce a gas into the sample container; and a second gas tube connected to the sample container to transfer a headspace gas of the sample container to the ion source, in which the ion source generates ions of the headspace gas and the mass spectrometry part performs mass spectrometry of the ions. Thereby, the mass spectrometer as a drug detection equipment can analyze various drugs in urine rapidly and with high sensitivity.Type: ApplicationFiled: August 22, 2011Publication date: March 1, 2012Inventors: Makoto Hashimoto, Takefumi Yokokura, Masuyoshi Yamada, Hiroyuki Inoue, Hidetoshi Morokuma
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Patent number: 8123496Abstract: A pump device which accurately detects a flow rate of a pump, performs real-time control of the flow rate, and thus can suppress a flow rate error caused by occurrence of pulsation. Control of a pump rotation speed by a pressure sensor has low responsiveness in a low pressure region, and a correlation between a pressure and a flow rate is incomplete in a high flow rate region. With this taken into consideration, a flow rate sensor is disposed at an outlet port of a second pump. A position detection sensor detects a point where a first pump is shifted from a suction mode to a discharge mode. Moreover, the flow rate sensor detects that there is no discharge from the pump, and that there is discharge from the pump alone. Accordingly, a controller sets a rotation speed of a motor to a speed double the previous speed (double the normal rotation speed).Type: GrantFiled: July 28, 2010Date of Patent: February 28, 2012Assignee: Hitachi High-Technologies CorporationInventors: Kimihiko Ishii, Kiyotoshi Mori, Masahito Ito, Hironori Kaji, Takefumi Yokokura
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Publication number: 20110248157Abstract: Objects of the present invention is to provide a quadrupole mass filter that can be fabricated at low cost and has a high transmission efficiency even under a high pressure (0.5 mTorr or more), and to provide a mass spectrometer or mass spectrometry method that reduces crosstalk in a wide mass range. Now, in a mass spectrometer, an ion separating unit is configured to include quadrupole rod electrodes that form a quadrupole radio-frequency electric field, electrodes that form a quadrupole electrostatic field, and a power supply that allows the voltage of the electrodes to form a quadrupole electrostatic field to change. In a collision cell configured to perform collision induced dissociation, harmonic potentials in a plurality of stages are produced to resonance excite ions in the axial direction, so that the ions obtain kinetic energy to move in the direction of the detector. This energy allows a time period to shorten for which ions stay in the collision cell.Type: ApplicationFiled: October 13, 2009Publication date: October 13, 2011Inventors: Masuyuki Sugiyama, Yuichiro Hashimoto, Hideki Hasegawa, Masuyoshi Yamada, Hiroyuki Yasuda, Shinji Nagai, Shintaro Kubo, Takefumi Yokokura
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Publication number: 20100288027Abstract: A pump device is realized, which accurately detects a flow rate of a pump, performs real-time control of the flow rate, and thus can suppress a flow rate error caused by occurrence of pulsation. Control of a pump rotation speed by a pressure sensor has low responsiveness in a low pressure region, and a correlation between a pressure and a flow rate is incomplete in a high flow rate region. With this taken into consideration, a flow rate sensor 10 is disposed at an outlet port 9 of a second pump 4. A position detection sensor 14 detects a point where a first pump 3 is shifted from a suction mode to a discharge mode. Moreover, the flow rate sensor 10 detects that there is no discharge from the pump 3, and that there is discharge from the pump 4 alone. Accordingly, a controller 15 sets a rotation speed of a motor 12 to a speed double the previous speed (double the normal rotation speed).Type: ApplicationFiled: July 28, 2010Publication date: November 18, 2010Applicant: Hitachi High-Technologies CorporationInventors: Kimihiko Ishii, Kiyotoshi Mori, Masahito Ito, Hironori Kaji, Takefumi Yokokura
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Publication number: 20090001007Abstract: Both a column having high-pressure resistance and capable of performing high-speed separation and analysis even with a small flow rate and a liquid chromatograph apparatus using thereof are to be provided. A separation column according to the present invention has a monolithic rod being arranged in the center, being made of a porous material, and having a circular cross section, a filler layer arranged such that it encircles a circumferential surface of the monolithic rod, and a cylindrical support medium arranged outside the filler layer. The filler layer is formed by filling a tube-like gap between the monolithic rod and the support medium with particles or beads.Type: ApplicationFiled: June 26, 2008Publication date: January 1, 2009Inventors: Katsutoshi Shimizu, Masahito Ito, Kimihiko Ishii, Yoshihiro Nagaoka, Kisaburo Deguchi, Takefumi Yokokura
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Publication number: 20070084766Abstract: A pump device is realized, which accurately detects a flow rate of a pump, performs real-time control of the flow rate, and thus can suppress a flow rate error caused by occurrence of pulsation. Control of a pump rotation speed by a pressure sensor has low responsiveness in a low pressure region, and a correlation between a pressure and a flow rate is incomplete in a high flow rate region. With this taken into consideration, a flow rate sensor 10 is disposed at an outlet port 9 of a second pump 4. A position detection sensor 14 detects a point where a first pump 3 is shifted from a suction mode to a discharge mode. Moreover, the flow rate sensor 10 detects that there is no discharge from the pump 3, and that there is discharge from the pump 4 alone. Accordingly, a controller 15 sets a rotation speed of a motor 12 to a speed double the previous speed (double the normal rotation speed).Type: ApplicationFiled: October 18, 2006Publication date: April 19, 2007Inventors: Kimihiko Ishii, Kiyotoshi Mori, Masahito Ito, Hironori Kaji, Takefumi Yokokura
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Patent number: 5378635Abstract: A method of measuring at least one of a catecholamine and its metabolite including a biological sample pretreatment process, a fluorescence inducing process of converting into a fluorescence inductor the at least one of a catecholamine and its metabolite in the biological sample subjected to pretreatment by means of a fluorescence inducing reagent, and a measuring process of separating and measuring said fluorescence inductor by liquid chromatography, said method being characterized by addition of a specified volume of maleimide before said process of making the biological sample fluorescent.Type: GrantFiled: October 6, 1993Date of Patent: January 3, 1995Assignee: Hitachi, Ltd.Inventors: Kenji Yasuda, Masami Aoki, Takefumi Yokokura