The Experts below are selected from a list of 27 Experts worldwide ranked by ideXlab platform

Yasuo Seto - One of the best experts on this subject based on the ideXlab platform.

  • Ion mobility spectrometric analysis of vaporous chemical warfare Agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation.
    Analytica Chimica Acta, 2015
    Co-Authors: Takafumi Satoh, Shintaro Kishi, Hisayuki Nagashima, Masumi Tachikawa, Mieko Kanamori-kataoka, Nakagawa Takao, Kitagawa Nobuyoshi, Tokita Kenichi, Yamamoto Soichiro, Yasuo Seto
    Abstract:

    The ion mobility behavior of nineteen chemical warfare Agents (7 nerve gases, 5 blister Agents, 2 lachrymators, 2 Blood Agents, 3 choking Agents) and related compounds including simulants (8 Agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two Blood Agents and three choking Agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar Agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare Agents examined the slope values for sarin, soman, tabun and nitrogen mustards were higher. Some CWA simulants and organic solvents gave the ion peaks eluting at the similar positions of the CWAs, resulting in false positive alarms.

  • correction to sensitive and comprehensive detection of chemical warfare Agents in air by atmospheric pressure chemical ionization ion trap tandem mass spectrometry with counterflow introduction
    Analytical Chemistry, 2014
    Co-Authors: Yasuo Seto, Hisashi Maruko, Hiroshi Sekiguchi, Shigeharu Yamashiro, Yasuhiro Sano, Yasuo Takayama, Ryoji Sekioka, Shintaro Yamaguchi, Shintaro Kishi, Takafumi Satoh
    Abstract:

    A highly sensitive and specific real-time field-deployable detection technology, based on counterflow air introduction atmospheric pressure chemical ionization, has been developed for a wide range of chemical warfare Agents (CWAs) comprising gaseous (two Blood Agents, three choking Agents), volatile (six nerve gases and one precursor agent, five blister Agents), and nonvolatile (three lachrymators, three vomiting Agents) Agents in air. The approach can afford effective chemical ionization, in both positive and negative ion modes, for ion trap multiple-stage mass spectrometry (MSn). The volatile and nonvolatile CWAs tested provided characteristic ions, which were fragmented into MS3 product ions in positive and negative ion modes. Portions of the fragment ions were assigned by laboratory hybrid mass spectrometry (MS) composed of linear ion trap and high-resolution mass spectrometers. Gaseous Agents were detected by MS or MS2 in negative ion mode. The limits of detection for a 1 s measurement were typically...

  • Decontamination of chemical and biological warfare Agents
    YAKUGAKU ZASSHI, 2009
    Co-Authors: Yasuo Seto
    Abstract:

    Chemical and biological warfare Agents (CBWA's) are diverse in nature; volatile acute low-molecular-weight toxic compounds, chemical warfare Agents (CWA's, gaseous choking and Blood Agents, volatile nerve gases and blister Agents, nonvolatile vomit Agents and lacrymators), biological toxins (nonvolatile low-molecular-weight toxins, proteinous toxins) and microbes (bacteria, viruses, rickettsiae). In the consequence management against chemical and biological terrorism, speedy decontamination of victims, facilities and equipment is required for the minimization of the damage. In the present situation, washing victims and contaminated materials with large volumes of water is the basic way, and additionally hypochlorite salt solution is used for decomposition of CWA's. However, it still remains unsolved how to dispose large volumes of waste water, and the decontamination reAgents have serious limitation of high toxicity, despoiling nature against the environments, long finishing time and non-durability in effective decontamination. Namely, the existing decontamination system is not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up the usable decontamination system surpassing the present technologies. The symposiast presents the on-going joint project of research and development of the novel decontamination system against CBWA's, in the purpose of realizing nontoxic, fast, specific, effective and economical terrorism on-site decontamination. The projects consists of (1) establishment of the decontamination evaluation methods and verification of the existing technologies and adaptation of bacterial organophosphorus hydrolase, (2) development of adsorptive elimination technologies using molecular recognition tools, and (4) development of deactivation technologies using photocatalysis.

  • On-Site Detection of Chemical Warfare Agents
    Handbook of Toxicology of Chemical Warfare Agents, 2009
    Co-Authors: Yasuo Seto
    Abstract:

    Publisher Summary Chemical warfare Agents (CWAs) are low-molecular weight synthetic compounds, which are fast acting and sometimes lethal, even at low levels, and in physical properties can be classified into gaseous Blood Agents, gaseous choking Agents, volatile nerve gases, volatile blister Agents, nonvolatile vomit Agents, and nonvolatile lacrimators. To measure the toxicity of a substance, a lethal concentration value is used. This value indicates the vapor concentration leading to 50% death in humans with 1 min inhalation. When considering toxicity manifestation time and vapor dispersion, the detection sensitivity for vapor concentration is one hundredth of LCt50 within 1 min. In the case of GB, this required detection sensitivity is 0.15 mg/m3, and at this level there is no odor and humans show no signs of toxicity. In the chemical weapon disposal situation, because the workers stay in one place for a long time, the time weighted average (TWA) values are the monitoring target for allowed operational conditions. These TWA values are approximately 1/100,000 of LCt50. The desired alarm time is to be less than several minutes. For portable-type detectors used by first responders, a combination of IMS and arrayed monitoring tape method machine is desirable. This combination covers gaseous to volatile CWAs. GC–MS helps to identify the detected CWAs. Nonvolatile CWAs are still unable to be detected by portable machines. For fixed-type detectors, highly sensitive detection equipment is necessary, and a combination of CFI-APCI-MS and a lined set of transmission-type monitoring tape method machines is almost perfect, covering all the CWAs with the required sensitivity.

  • detection performance of chemical warfare agent with portable aspiration type ion mobility spectrometer
    Bunseki Kagaku, 2006
    Co-Authors: Hisashi Maruko, Yasuo Seto, Hiroshi Sekiguchi, Akiyoshi Sato
    Abstract:

    The detection performance of a portable aspiration-type ion mobility spectrometer (ChemPro100, Environics) was investigated with nerve gases, blister Agents, Blood Agents and related compounds. The vapors of sarin, soman, tabun were recognized as "Nerve (nerve gas)" after about 10∼20 s sampling, and the detection limits were below 0.1 mg/m3. The vapors of mustard gas and lewisite 1 were recognized as "Blister (blister agent)" after about 10∼20 s sampling, and the detection limits were several mg/m3. The gases of hydrogen cyanide and cyanogen chloride were not recognized as "Blood (Blood agent)". The vapors of nerve gas simulants, such as dimethylmethylphosphonate and N,N -dimethylformamide, were recognized as "Nerve", and the vapors of blister agent simulants, such as 2-chloroethylethylsulfide, ethanol, toluence and chloroform, were recognized as "Blister". The other solvents were recognized as "Unknown chemical".

Takafumi Satoh - One of the best experts on this subject based on the ideXlab platform.

  • Ion mobility spectrometric analysis of vaporous chemical warfare Agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation.
    Analytica Chimica Acta, 2015
    Co-Authors: Takafumi Satoh, Shintaro Kishi, Hisayuki Nagashima, Masumi Tachikawa, Mieko Kanamori-kataoka, Nakagawa Takao, Kitagawa Nobuyoshi, Tokita Kenichi, Yamamoto Soichiro, Yasuo Seto
    Abstract:

    The ion mobility behavior of nineteen chemical warfare Agents (7 nerve gases, 5 blister Agents, 2 lachrymators, 2 Blood Agents, 3 choking Agents) and related compounds including simulants (8 Agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two Blood Agents and three choking Agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar Agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare Agents examined the slope values for sarin, soman, tabun and nitrogen mustards were higher. Some CWA simulants and organic solvents gave the ion peaks eluting at the similar positions of the CWAs, resulting in false positive alarms.

  • correction to sensitive and comprehensive detection of chemical warfare Agents in air by atmospheric pressure chemical ionization ion trap tandem mass spectrometry with counterflow introduction
    Analytical Chemistry, 2014
    Co-Authors: Yasuo Seto, Hisashi Maruko, Hiroshi Sekiguchi, Shigeharu Yamashiro, Yasuhiro Sano, Yasuo Takayama, Ryoji Sekioka, Shintaro Yamaguchi, Shintaro Kishi, Takafumi Satoh
    Abstract:

    A highly sensitive and specific real-time field-deployable detection technology, based on counterflow air introduction atmospheric pressure chemical ionization, has been developed for a wide range of chemical warfare Agents (CWAs) comprising gaseous (two Blood Agents, three choking Agents), volatile (six nerve gases and one precursor agent, five blister Agents), and nonvolatile (three lachrymators, three vomiting Agents) Agents in air. The approach can afford effective chemical ionization, in both positive and negative ion modes, for ion trap multiple-stage mass spectrometry (MSn). The volatile and nonvolatile CWAs tested provided characteristic ions, which were fragmented into MS3 product ions in positive and negative ion modes. Portions of the fragment ions were assigned by laboratory hybrid mass spectrometry (MS) composed of linear ion trap and high-resolution mass spectrometers. Gaseous Agents were detected by MS or MS2 in negative ion mode. The limits of detection for a 1 s measurement were typically...

Shintaro Kishi - One of the best experts on this subject based on the ideXlab platform.

  • Ion mobility spectrometric analysis of vaporous chemical warfare Agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation.
    Analytica Chimica Acta, 2015
    Co-Authors: Takafumi Satoh, Shintaro Kishi, Hisayuki Nagashima, Masumi Tachikawa, Mieko Kanamori-kataoka, Nakagawa Takao, Kitagawa Nobuyoshi, Tokita Kenichi, Yamamoto Soichiro, Yasuo Seto
    Abstract:

    The ion mobility behavior of nineteen chemical warfare Agents (7 nerve gases, 5 blister Agents, 2 lachrymators, 2 Blood Agents, 3 choking Agents) and related compounds including simulants (8 Agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two Blood Agents and three choking Agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar Agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare Agents examined the slope values for sarin, soman, tabun and nitrogen mustards were higher. Some CWA simulants and organic solvents gave the ion peaks eluting at the similar positions of the CWAs, resulting in false positive alarms.

  • correction to sensitive and comprehensive detection of chemical warfare Agents in air by atmospheric pressure chemical ionization ion trap tandem mass spectrometry with counterflow introduction
    Analytical Chemistry, 2014
    Co-Authors: Yasuo Seto, Hisashi Maruko, Hiroshi Sekiguchi, Shigeharu Yamashiro, Yasuhiro Sano, Yasuo Takayama, Ryoji Sekioka, Shintaro Yamaguchi, Shintaro Kishi, Takafumi Satoh
    Abstract:

    A highly sensitive and specific real-time field-deployable detection technology, based on counterflow air introduction atmospheric pressure chemical ionization, has been developed for a wide range of chemical warfare Agents (CWAs) comprising gaseous (two Blood Agents, three choking Agents), volatile (six nerve gases and one precursor agent, five blister Agents), and nonvolatile (three lachrymators, three vomiting Agents) Agents in air. The approach can afford effective chemical ionization, in both positive and negative ion modes, for ion trap multiple-stage mass spectrometry (MSn). The volatile and nonvolatile CWAs tested provided characteristic ions, which were fragmented into MS3 product ions in positive and negative ion modes. Portions of the fragment ions were assigned by laboratory hybrid mass spectrometry (MS) composed of linear ion trap and high-resolution mass spectrometers. Gaseous Agents were detected by MS or MS2 in negative ion mode. The limits of detection for a 1 s measurement were typically...

Hisashi Maruko - One of the best experts on this subject based on the ideXlab platform.

  • correction to sensitive and comprehensive detection of chemical warfare Agents in air by atmospheric pressure chemical ionization ion trap tandem mass spectrometry with counterflow introduction
    Analytical Chemistry, 2014
    Co-Authors: Yasuo Seto, Hisashi Maruko, Hiroshi Sekiguchi, Shigeharu Yamashiro, Yasuhiro Sano, Yasuo Takayama, Ryoji Sekioka, Shintaro Yamaguchi, Shintaro Kishi, Takafumi Satoh
    Abstract:

    A highly sensitive and specific real-time field-deployable detection technology, based on counterflow air introduction atmospheric pressure chemical ionization, has been developed for a wide range of chemical warfare Agents (CWAs) comprising gaseous (two Blood Agents, three choking Agents), volatile (six nerve gases and one precursor agent, five blister Agents), and nonvolatile (three lachrymators, three vomiting Agents) Agents in air. The approach can afford effective chemical ionization, in both positive and negative ion modes, for ion trap multiple-stage mass spectrometry (MSn). The volatile and nonvolatile CWAs tested provided characteristic ions, which were fragmented into MS3 product ions in positive and negative ion modes. Portions of the fragment ions were assigned by laboratory hybrid mass spectrometry (MS) composed of linear ion trap and high-resolution mass spectrometers. Gaseous Agents were detected by MS or MS2 in negative ion mode. The limits of detection for a 1 s measurement were typically...

  • detection performance of chemical warfare agent with portable aspiration type ion mobility spectrometer
    Bunseki Kagaku, 2006
    Co-Authors: Hisashi Maruko, Yasuo Seto, Hiroshi Sekiguchi, Akiyoshi Sato
    Abstract:

    The detection performance of a portable aspiration-type ion mobility spectrometer (ChemPro100, Environics) was investigated with nerve gases, blister Agents, Blood Agents and related compounds. The vapors of sarin, soman, tabun were recognized as "Nerve (nerve gas)" after about 10∼20 s sampling, and the detection limits were below 0.1 mg/m3. The vapors of mustard gas and lewisite 1 were recognized as "Blister (blister agent)" after about 10∼20 s sampling, and the detection limits were several mg/m3. The gases of hydrogen cyanide and cyanogen chloride were not recognized as "Blood (Blood agent)". The vapors of nerve gas simulants, such as dimethylmethylphosphonate and N,N -dimethylformamide, were recognized as "Nerve", and the vapors of blister agent simulants, such as 2-chloroethylethylsulfide, ethanol, toluence and chloroform, were recognized as "Blister". The other solvents were recognized as "Unknown chemical".

Hiroshi Sekiguchi - One of the best experts on this subject based on the ideXlab platform.

  • correction to sensitive and comprehensive detection of chemical warfare Agents in air by atmospheric pressure chemical ionization ion trap tandem mass spectrometry with counterflow introduction
    Analytical Chemistry, 2014
    Co-Authors: Yasuo Seto, Hisashi Maruko, Hiroshi Sekiguchi, Shigeharu Yamashiro, Yasuhiro Sano, Yasuo Takayama, Ryoji Sekioka, Shintaro Yamaguchi, Shintaro Kishi, Takafumi Satoh
    Abstract:

    A highly sensitive and specific real-time field-deployable detection technology, based on counterflow air introduction atmospheric pressure chemical ionization, has been developed for a wide range of chemical warfare Agents (CWAs) comprising gaseous (two Blood Agents, three choking Agents), volatile (six nerve gases and one precursor agent, five blister Agents), and nonvolatile (three lachrymators, three vomiting Agents) Agents in air. The approach can afford effective chemical ionization, in both positive and negative ion modes, for ion trap multiple-stage mass spectrometry (MSn). The volatile and nonvolatile CWAs tested provided characteristic ions, which were fragmented into MS3 product ions in positive and negative ion modes. Portions of the fragment ions were assigned by laboratory hybrid mass spectrometry (MS) composed of linear ion trap and high-resolution mass spectrometers. Gaseous Agents were detected by MS or MS2 in negative ion mode. The limits of detection for a 1 s measurement were typically...

  • detection performance of chemical warfare agent with portable aspiration type ion mobility spectrometer
    Bunseki Kagaku, 2006
    Co-Authors: Hisashi Maruko, Yasuo Seto, Hiroshi Sekiguchi, Akiyoshi Sato
    Abstract:

    The detection performance of a portable aspiration-type ion mobility spectrometer (ChemPro100, Environics) was investigated with nerve gases, blister Agents, Blood Agents and related compounds. The vapors of sarin, soman, tabun were recognized as "Nerve (nerve gas)" after about 10∼20 s sampling, and the detection limits were below 0.1 mg/m3. The vapors of mustard gas and lewisite 1 were recognized as "Blister (blister agent)" after about 10∼20 s sampling, and the detection limits were several mg/m3. The gases of hydrogen cyanide and cyanogen chloride were not recognized as "Blood (Blood agent)". The vapors of nerve gas simulants, such as dimethylmethylphosphonate and N,N -dimethylformamide, were recognized as "Nerve", and the vapors of blister agent simulants, such as 2-chloroethylethylsulfide, ethanol, toluence and chloroform, were recognized as "Blister". The other solvents were recognized as "Unknown chemical".