Kyushu University Academic Staff Educational and Research Activities Database
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Tomoko Imasaka Last modified date:2018.08.18



Graduate School


E-Mail
Phone
092-553-4462
Fax
092-553-4462
Academic Degree
Dr. of Engineering
Field of Specialization
Theoretical Chemistry, Physical Chemistry, Statistical Mechanics, Analytical Chemistry
Research
Research Interests
  • The high sensitive and exhaustive measurement of the chemical munitions agent
    -Theoretical prediction of the spectrophotometric property by the quantum chemistry calculation-
    keyword : Quantum Chemical Calculation
    2015.04.
  • Analysis of Persistent Organic Pollutants (POPs) in the Environment Using a Femtosecond Laser
    keyword : POPs
    2014.04~2016.03.
  • Comprehensive high sensitivity detection of explosives terrorism based on the theoretical prediction by quantum chemical calculations
    keyword : quantum chemical calculation, mass spectrum
    2012.04~2015.03.
  • The theoretical prediction of the spectrum of ultra-high-speed optical ionization mass spectrometry of terrorism-related material
    keyword : quantum chemical calculation, mass spectrum, ionization energy
    2008.04.
  • Data Processing Technique in Mass Spectrometry
    keyword : reliability factor, mass spectrum, dioxins, Fortran programming
    2007.04.
  • The theoretical prediction of the mass spectrum in quiantum computational chemistry.
    keyword : dioxins, S0-S1 transition, ionization potential
    2001.04.
  • Mean-Field Theory of the Orientational Ordering of Dipolar Guest Molecules in β-Hydroquinone Clathrate
    keyword : statistical mechanics, theoretical chemistry, clathrate
    1988.05~2001.04.
Current and Past Project
  • Comprehensive high sensitivity detection of explosives terrorism based on the theoretical prediction by quantum chemical calculations
Academic Activities
Reports
1. The calculation of spectrum, Shoji Hiorokawa, Tomoko Imasaka, Masataka Oishi, Yoshikazu Oyakawa, NEDO.
2. The dipole-dipole interaction and the phase transition of SO2-β Quinol clathrare, Tomoko Imasaka and Shoji Hirokawa, Division of the Organic Crystals, The Chemical Society of Japan.
Papers
1. Xixiang Yang, Tomoko Imasaka, Totaro Imasaka, Determination of pesticides by gas chromatography combined with mass spectrometry using femtosecond lasers emitting at 267, 400, and 800 nm as the ionization source, Analytical Chemistry, 10.1021/acs.analchem.8b00537, 90, 4886-4893, 2018.03,  Analytical ChemistryにDetermination of pesticides by gas chromatography combined with mass spectrometry using femtosecond lasers emitting at 267, 400, and 800 nm as the ionization sourceと題した論文を発表した。著者はX. Yang, T. Imasaka, T. Imasaka、巻、ページ、年は vol. 90 (7), p. 4886–4893 (2018) である。.
2. Adan Li, Tomoko Imasaka, Totaro Imasaka, Optimal Laser Wavelength for Femtosecond Ionization of Polycyclic Aromatic Hydrocarbons and their Nitrated Compounds in Mass Spectrometry, Analytical Chemistry, DOI: 10.1021/acs.analchem.8b00125, 90, 2963-2969, 2018.01,  Analytical ChemistryにOptimal Laser Wavelength for Femtosecond Ionization of Polycyclic Aromatic Hydrocarbons and their Nitrated Compounds in Mass Spectrometryと題した論文を発表した。発表者はA. Li, T. Imasaka, T. Imasaka、巻、ページ、年はvol. 90, p.2963-2969 (2018) である。.
3. T. Fujii, T. Imasaka, T. Imasaka, Use of chemical conversion for determination of nitrated aromatic hydrocarbons using femtosecond ionization mass spectrometry, Analytica Chimica Acta, DOI: 10.1016/j.aca.2017.09.049, DOI: 10.1016/j.aca.2017.09.049, 996, 48-53, 2017.10.
4. A. Li, D.P.Dinh, T. Imasaka, T. Imasaka, Suppression of Fragmentation in Multiphoton Ionization Mass Spectrometry Using a Near-infrared Femtosecond Laser as an Ionization Source, Analyst, DOI: 10.1039/c7an01172e, 142, 3942-3947, 2017.09.
5. Akifumi Hamachi, Tomoko Imasaka, Hiroshi Nakamura, Totaro Imasaka, Adan Li, Determination of Nerve Agent Metabolites by Ultraviolet Femtosecond Laser Ionization Mass Spectrometry, Analytical Chemistry, DOI:10.1021/acs.analchem.7b00386, 89, 9, 5030-5035, 2017.04,  Analytical ChemistryにDetermination of Nerve Agent Metabolites by Ultraviolet Femtosecond Laser Ionization Mass Spectrometryと題する論文を発表した。著者はA. Hamachi, T. Imasaka, H. Nakamura, A. Li, T. Imasaka、巻、ページ、年はvol. 89(9), pp.5030-5035, (2017) である。.
6. Shimpei Shibuta, Tomoko Imasaka, Totaro Imasaka, Determination of Fragrance Allergens by Ultraviolet Femtosecond Laser Ionization Mass Spectrometry, Analytical Chemistry, DOI:10.1021/acs.analchem.6b03229, DOI:10.1021/acs.analchem.6b03229, 88, 10693-10700, 2016.10,  Analytical ChemistryにDetermination of Fragrance Allergens by Ultraviolet Femtosecond Laser Ionization Mass Spectrometry と題する論文を発表した。著者はS. Shibuta, T. Imasaka, T. Imasaka、巻、ページはvol. 88, pp.10693-10700 (2016)。.
7. Yang Xixiang, Tomoko Imasaka, Li Adan, Totaro Imasaka, Determination of hexachlorocyclohexane by gas chromatography/multiphoton onization/time-of-flight mass spectrometr, Journal of The American Society for Mass Spectrometry, DOI: 10.1007/s13361-016-1497-7, 27, 1999-2005, 2016.09.
8. Yuanyuan Tang, Tomoko Imasaka, Shigekazu Yamamoto, Totaro Imasaka, Determination of Polycyclic Aromatic Hydrocarbons and Their Nitro-, Amino- Derivatives Absorbed on Particulate Matter 2.5 by Multiphoton Ionization Mass Spectrometry Using Far-, Deep-, and Near-Ultraviolet Femtosecond Lasers, Chemosphere, DOI:10.1016/j.chemosphere.2016.02.114, 152, 252-258, 2016.06,  Analytical ChemistryにDetermination of Fragrance Allergens by Ultraviolet Femtosecond Laser Ionization Mass Spectrometry と題する論文を2016年に発表した。著者はS. Shibuta, T. Imasaka, T. Imasaka、巻号、ページはvol. 88, pp.10693-10700である。
 .
9. Tomoko Imasaka, Akifumi Hamachi, Tomoya Okuno, Totaro Imasaka, A Simple Method for Evaluation of Pulse Width of an Ultraviolet Femtosecond Laser Used in Two-Photon Ionization Mass Spectrometry, Applied Sciences, DOI:10.3390/app6050136, 6, 5, 136, 2016.05.
10. V.T.T. Duong, V. Duong, N.T.H. Lien, T. Imasaka, Y. Tang, S. Shibuta, A. Hamachi, D. Q. Hoa, T. Imasaka, Detection of polychlorinated biphenyls in transformer oils in Vietnam by multiphoton ionization mass spectrometry using a far-ultraviolet femtosecond laser as an ionization source, Talanta, DOI:10.1016/j.talanta.2015.11.054, 149, 275-279, 2016.03, Polychlorinated biphenyls (PCBs) in transformer and food oils were measured using gas chromatography
combined with multiphoton ionization mass spectroscopy. An ultrashort laser pulse emitting in the
far-ultraviolet region was utilized for efficient ionization of the analytes. Numerous signal peaks were
clearly observed for a standard sample mixture of PCBs when the third and fourth harmonic emissions
(267 and 200 nm) of a femtosecond Ti:sapphire laser (800 nm) were employed. The signal intensities
were found to be greater when measured at 200 nm compared with those measured at 267 nm, providing
lower detection limits especially for highly chlorinated PCBs at shorter wavelengths. After simple
pretreatment using disposable columns, PCB congeners were measured and found to be present in the
transformer oils used in Vietnam..
11. Noboru Itouyama, Taiki Matsui, Shigekazu Yamamoto, Tomoko Imasaka, Totaro Imasaka, Analysis of Parent/Nitrated Polycyclic Aromatic Hydrocarbons in Particulate Matter 2.5 Based on Femtosecond Ionization Mass Spectrometry, Journal of The American Society for Mass Spectrometry, DOI:10.1007/s13361-015-1276-x, 27, 293-300, 2016.02.
12. Tang Yuanyuan, Tomoko Imasaka, Shigekazu Yamamoto, Totaro Imasaka, Multiphoton Ionization Mass Spectrometry of Nitrated Polycyclic Aromatic Hydrocarbons, Talanta, DOI:10.1016/j.talanta.2015.03.027, 140, 109-114, 2015.08.
13. Yoshinari Takao, Tomoko Imasaka, Yuichiro Kida, Totaro Imasaka, Autocorrelation and Frequency-Resolved Optical Gating Measurements Based on the Third Harmonic Generation in a Gaseous Medium, Applied Sciences, 10.3390/app5020136, 5, 136-144, 2015.06.
14. Tomoko Imasaka, Akifumi Hamachi, Tomoya Okuno, Totaro Imasaka, A simple method for the measurement of the optical pulse width on-site the mass spectrometer, 2015 Conference on Lasers and Electro-Optics (CLEO), JTu5A.7, 2015.05.
15. Akifumi Hamachi, Tomoya Okuno, Tomoko Imasaka, Yuichiro Kida, Totaro Imasaka, Resonant and nonresonant multiphoton ionization processes in mass spectrometry of explosives, Analytical Chemistry, ac-2014-04667t.R1, 87, 3027-3031, 2015.03.
16. Tomoko Imasaka, Totaro Imasaka, An Evaluation of the Spectral Properties of Nerve Agents for Laser Ionization Mass Spectrometry, Analytical Sciences, 10.2116/analsci.30.1113, 30, 12, 1113-1120, 2014.12.
17. Ryota Ezoe, Tomoko Imasaka, Totaro Imasaka, Determination of Triacetone Triperoxide Using Ultraviolet Femtosecond Multiphoton
Ionization Time-of-Flight Mass Spectrometry, Analytica Chimica Acta, 10.1016/j.aca.2014.10.045, 853, 508-513, 2014.11.
18. Tomoya Okuno, Tomoko Imasaka, Yuichiro Kida, Totaro Imasaka, Autocorrelator for measuring an ultrashort optical pulse width in the ultraviolet region based on two-photon ionization of an organic compound , Optics Communications, 10.1016/j.optcom.2013.07.055, 310, 48-52, 2014.01.
19. Tomoko Imasaka, Tomoya Okuno, Totaro Imasaka, The Search for a molecule to measure an autocorrelation trace of the second/third harmonic emission of a Ti:sapphire laser based on two-photon resonant excitation and subsequent one photon ionization, Applied Physics B:Lasers and Optics, 10.1007/s00340-013-5505-3, 113, 4, 543-549, 2013.05, The temporal profile of the second and third harmonic emissions of a Ti:sapphire laser was measured using an autocorrelator consisting of a mass spectrometer as a twophoton-response detector. A number of organic compounds that are potentially applicable for two-photon excitation and subsequent one photon ionization were investigated using density functional theory calculations. N, N'-dimethylaniline and acetonitrile were used for the measurement of the pulse width for the second and third harmonic emissions of the Ti:sapphire laser. This approach has the potential for use in measuring pulse widths as short as 1~3 fs in the ultraviolet region..
20. Tomoko Imasaka and Totaro Imasaka, Searching for a molecule with a wide frequency domain for non-resonant two-photon ionization to measure the ultrashort optical pulse width, Opt. Commun. , 10.1016/j.optcom.2012.04.015, 285, 3514-3518, 2012.06, The frequency domain of non-resonant two-photon ionization, defined as a frequency
separation from half of the ionization energy to the excitation energy, was investigated using density functional theory calculations. Several organic compounds have the potential for use in the measurement of the ultrashort optical pulse width in the ultraviolet region using an autocorrelator consisting of a mass spectrometer as a two-photon-response detector..
21. Tomoko Imasaka and Totaro Imasaka, Molecules with a One Octave Frequency Domain for the Measurement of the 1-fs Optical Pulse Width, Conference on Lasers and Electro-Optics (CLEO), JTh2A.15, 2012.05.
22. Osamu Shitamichi, Tomoko Imasaka, Tomohiro Uchimura, Totaro Imasaka, Multiphoton Ionization/Mass Spectrometry of Polybrominated Diphenyl Ethers, Analytical Methods, 3, 2322-2327, 2011.10.
23. Li Adan, Tomoko Imasaka, Tomohiro Uchimura, Totaro Imasaka, Analysis of Pesticides by Gas Chromatography / Multiphoton Ionization / Mass Spectrometry Using a Femtosecond Laser, Analytica Chimica Acta, 701, 52-59, 2011.07.
24. Yuka Watanabe-Ezoe, Xing Li, Tomoko Imasaka, Tomohiro Uchimura, Totaro Imasaka, Gas Chromatography/Femtosecond Multiphoton Ionization/Time-of-Flight Mass Spectrometry of Dioxins, Analytical Chemistry, 82, 6519-6525, 2010.07.
25. Takashi Shimizu, Yuka Watanabe-Ezoe, Satoshi Yamaguchi, Hiroko Tsukatani, Tomoko Imasaka, Shin-ichi Zaitsu, Tomohiro Uchimura, and Totaro Imasaka, Enhancement of Molecular Ions in Mass Spectrometry Using an Ultrashort Optical Pulse in Multiphoton Ionization, Analytical Chemistry, 10.1021/ac1003773, 82, 3441-3444, 82, 3441-3444, 2010.04.
26. Shoji Hirokawa, Tomoko Imasaka, Totaro Imasaka, The S-1 ← S-0 0-0 transition energies of polychlorinated dibenzofurans (PCDFs) revisited: CIS(D) and MP2 calculations with correction for correlation energies, Journal of Molecular Structure -Theochem, 10.1016/j.theochem.2009.08.021 , 915, 1-3, 79-85, Volume: 915 Issue: 1-3 Pages: 79-85 , 2009.12.
27. Satoshi Yamaguchi, Tomohiro Uchimura, Tomoko Imasaka, Totaro Imasaka, Gas chromatography/time-of-flight mass spectrometry of triacetone triperoxide based on femtosecond laser ionization, Rapid Communications in Mass Spectrometry , 10.1002/rcm.4225 , 23, 19, 3101-3106, Volume: 23 Issue: 19 Pages: 3101-3106 , 2009.10.
28. Hiroko Tsukatani, Hiroki Okudaira, Tomohiro Uchimura, Tomoko Imasaka,Totaro Imasaka, Selective Ionization of 2,4-Xylenol in Mass Spectrometry Using a Tunable Laser and Supersonic Jet Technique, Analytical Sciences, 10.2116/analsci.25.599, 25, 5, 599-604, Volume: 25 Issue: 5 Pages: 599-604, 2009.05.
29. Tomoko Imasaka, Nami Nakamura, Yuji Sakoda, Satoshi Yamaguchi, Yuka Watanabe-Ezoe, Tomohiro Uchimura, Totaro Imasaka, Data processing technique in gas chromatography/time-of-flight mass spectrometry, Analyst (Royal Soc Chemistry), 10.1039/b815630a , 134, 4, 712-718, Volume: 134 Issue: 4 Pages: 712-718, 2009.02.
30. Satoshi Yamaguchi, Fumiaki Kira, Yuki Miyoshi, Tomohiro Uchimura, Yuka Watanabe-Ezoe, Shin-ichi Zaitsu , Tomoko Imasaka, Totaro Imasaka, Near-ultraviolet femtosecond laser ionization of dioxins in gas chromatography/time-of-flight mass spectrometry, Analytica Chimica Acta , 10.1016/j.aca.2008.11.005 , 63, 12, 229-233, Volume: 632 Issue: 2 Pages: 229-233 , 2009.01.
31. Yuka Watanabe-Ezoe, Nami Nakamura, Tomohiro Uchimura, Satoshi Yamaguchi, Tomoko Imasaka, Totaro Imasaka, Gas Chromatography/Multiphoton Ionization/Mass Spectrometry of Pentachlorodibenzofurans in Soils, Organohalogen Compounds, 70, 2396-2399 , Vol. 70, pp.2396-2399, 2008.12.
32. Tomoko Imasaka, Shoji Hirokawa, Totaro Imasaka, Ab initio MO study on the S-1 ← S-0 origin transition energies of polychlorodibenzofurans (PCDFs), Journal of Molecular Structure-Theochem, 10.1016/j.theoshem.2006.07.005 , 774, 1-3, 7-12, Volume: 774 Issue: 1-3 Pages: 7-12, 2006.11.
33. Shoji Hirokawa, Tomoko Imasaka, Yoshikazu Oyakawa, Masataka Oishi, Totaro Imasaka, Conformational changes and S-1 ← S-0 origin transition energies: Polychlorinated biphenyls (PCBs), Journal of Molecular Structure-Theochem, 10.1016/j.theochem.2006.06.009 , 772, 1-3, 31-37, Volume: 772 Issue: 1-3 Pages: 31-37 , 2006.10.
34. Shoji Hirokawa, Tomoko Imasaka, Totaro Imasaka, Chlorine substitution pattern, molecular electronic properties, and the nature of the ligand-receptor interaction: Quantitative property-activity relationships of polychlorinated dibenzofurans, Chemical Research in Toxicology (American Chemical Society), 10.1021/tx049874f, 18, 2, 232-238, Volume: 18 Issue: 2 Pages: 232-238 , 2005.02.
35. Tomoko Imasaka, Shoji Hirokawa , Additivity of electron correlation energy and the ab initio MO calculation of (0-0) S-1 ← S-0 transition energies: polychlorinated dibenzofurans, Journal of Molecular Structure-Theochem, 10.1016/j.theochem.2004.08.003 , 710, 1-3, 19-23, Volume: 710 Issue: 1-3 Pages: 19-23, 2004.11.
36. Shoji Hirokawa,Tomoko Imasaka,Yoshihiro Urakami, Ab initio MO study on the S-1 ← S-0 transitions of polychlorinated dibenzo-p-dioxins, Journal of Molecular Structure-Theochem, 10.1016/S0166-1280(02)00648-6 , 3, 229-237, Volume: 622 Issue: 3 Pages: 229-237, 2003.03.
37. Tomoko Imasaka, Shoji Hirokawa, Mean-field theory of the orientational ordering of dipolar guest molecules in beta-hydroquinone clathrate of SO2 and D2S, Journal of the Physical Society of Japan , 10.1143/jpsj.70.2603, 70, 9, 2603-2612, Volume: 70 Issue: 9 Pages: 2603-2612 , 2001.09.
38. Tomoko Imasaka, Shoji Hirokawa, Effects of a crystal field on the orientational phase transition in a system of dipoles: A mean-field study of SO2-beta-hydroquinone clathrate, Journal of the Physical Society of Japan , 10.1143/jpsj.66.1364, 66, 5, 1364-1370, Volume: 66 Issue: 5 Pages: 1364-1370 , 1997.05.
39. Shoji Hirokawa, Tomoko Imasaka,Takasuke Matsuo, Quantum Effects on the Orientational Ordering of H2S and D2S Molecules Enclosed in Beta-Quinol Clathrate, Journal of the Physical Society of Japan, 63, 2, 593-601, Volume: 63 Issue: 2 Pages: 593-601 , 1994.02.
40. Shoji Hirokawa, Tomoko Imasaka, Effect of a Cryatal-Field on the Orientational of H2S Molecules Enclosed in Beta-Quinol Clathrate, Journal of the Physical Society of Japan , 59, 10, 3797-3798, Volume: 59 Issue: 10 Pages: 3797-3798 , 1990.10.
41. Shoji Hirokawa, Tomoko Iwasaki (Imasaka), Orientational Order of Guest H2S Molecules in β-Quinol Clathrate, Journal of the Physical Society of Japan, 10.1143/jpsj.63.593, 57, 11, 3843-3850, Volume: 57 Issue: 11 Pages: 3843-3850 , 1988.11.
Presentations
1. Xixiang Yang, Tomoko Imasaka, and Totaro Imasaka, Multi-residue determination of pesticides by femtosecond lasers ionization mass spectrometry, The 14th Asian Conference on Analytical Sciences , 2018.04.
2. V. V. Son, H. Nakamura, T. Imasaka, T. Imasaka, Determination of nerve agent metabolites in human urine by ultraviolet femtosecond laser ionization mass spectrometry using 2-bromomethyl naphthalene as the derivatizing reagent, 14th Asian Conference on Analytical Science, 2018.04.
3. T. Ju, K. Yoshinaga , H. Nakamura, A. Li ,T. Imasaka, T. Imasaka, Photoionization mass spectrometry based on time-correlated single ion counting using a femtosecond laser, 14th Asian Conference on Analytical Science, 2018.04.
4. Y. Tang, A. Li, T. Imasaka, T. Imasaka, Femtosecond ionization mass spectrometry for trace analysis of environmental pollutants adsorbed on particulate matter 2.5, 14th Asian Conference on Analytical Science, 2018.04.
5. T. Ju, K. Yoshinaga, H. Nakamura, L. Adan, T. Imasaka, T. Imasaka, Time-correlated single ion counting in time-of-flight femtosecond-laser-ionization mass spectrometry, 日本分析化学会第66年会, 2017.09.
6. L. Adan, P.D. Thang, T. Imasaka, T. Imasaka, Femtosecond laser induced ionization and dissociation of pentachlorobenzene studied by time-of-flight mass spectrometry, 日本分析化学会第66年会, 2017.09.
7. K. Kojima, T. Imasaka, T. Imasaka, Femtosecond ionization mass spectrometry -A new tool for practical trace analysis in environmental science and technology-, Euroanalysis 2017, 2017.08.
8. T. Imasaka, X. Yang, L. Adan, T. Imasaka, Theoretical calculation of the elution order of (+/-)-α-hexachlorocyclohexane separated by a stationary phase consisting of permethylated γ-cyclodextrin in gas chromatography, Euroanalysis 2017, 2017.08.
9. Akifumi Hamachi, Tomoko Imasaka, Totaro Imasaka, Femtosecond ionization mass spectrometry: an advanced tool for the analysis of pollutants, explosives, and nerve agents, 13th Asian Conference on Analytical Sciences (ASIANALYSIS XIII), 2016.12,  Femtosecond ionization mass spectrometry: an advanced tool for the analysis of pollutants, explosives, and nerve agentsと題した発表を13th Asian Conference on Analytical Sciences (ASIANALYSIS XIII)で、Plenary lectureとして発表を行った。著者はA. Hamachi, T. Imasaka, T. Imasaka、場所はChiang Mai, Thailand、日時は 10:45-11:15, 11 Dec., 2016、発表番号はPL-8。.
10. Takuya Fujii, Tomoko Imasaka, Totaro Imasaka, An ultraviolet femtosecond laser for multiphoton ionization in mass spectrometry, Joint 13th Asia Pacific Physics Conference and 22nd Australian Institute of Physics Congress, 2016.12, Joint 13th Asia Pacific Physics Conference and 22nd Australian Institute of Physics Congressにおいて、An ultraviolet femtosecond laser for multiphoton ionization in mass spectrometryと題する発表をKeynote presentationとして行った。著者はT. Fujii, T. Imasaka, T. Imasaka、場所はBrisbane, Australia、日時は12:00-12:30, 8 Dec., 2016、セッションはAOC Session 10, Topic: Atto- and Femtosecond physicsである。



(Dec. 4-8, 2016, Brisbane Convention and Exhibition Centre, Brisbane, Australia) AOC Session 10, Topic: Atto- and Femtosecond physics, Keynote presentation (12:00-12:30, 8 Dec., 2016).
11. Akifumi Hamachi, Hiroaki Kouno, Tomoko Imasaka, Totaro Imasaka, Efficient nonresonant multiphoton ionization in the femtosecond region, Joint 13th Asia Pacific Physics Conference and 22nd Australian Institute of Physics Congress, 2016.12.
12. Shinpei Shibuta, Tomoko Imasaka, Totaro IMASAKA, Femtosecond Laser Ionization in Mass Spectrometry and Its Application to Trace Analysis of Allergy Substances in Fragrances., Seminar of the Joint Mass Spectrometry Centre, the Virtual Helmholtz Institute HICE-Aerosols & Health and the Chair of Analytical Chemistry@University of Rostock: Summer term 2016, 2016.06.
13. Shinpei Shibuta, Tomoko Imasaka, Totaro Imasaka, Determination of Allergy Substances in Fragrance by Capillary Gas Chromatography / Laser Ionization Mass Spectrometry Using a Femtosecond Laser as an Ionization Source., 40th International Symposium on Capillary Chromatography and 13th GCxGC Symposium, 2016.05, Laser ionization mass spectrometry is a powerful technique for trace analysis of organic
compounds. When this technique is combined with capillary gas chromatography, more than
hundreds of compounds can be measured simultaneously on the two-dimensional display. In
fact, toxic substances such as dioxins, pesticides, and nitro-aromatic hydrocarbons have been
measured. However, the sensitivity is limited for compounds having no absorption bands at the
laser wavelength. In this study, we measured 26 organic compounds known as allergens in
fragrance using a deep-ultraviolet (DUV, 267 nm) or far-ultraviolet (FUV, 200 nm) femtosecond
laser as an ionization source.
Some of the allergens have no absorption bands in the DUV region. Then, the fourth harmonic
emission (200 nm) as well as the third harmonic emission (267 nm) of a Ti:sapphire laser was
utilized for multiphoton ionization. The detection limits were improved for several compounds,
e.g., methyleugenol, using the FUV laser due to a larger molar absorptivity at 200 nm. On the
other hand, some of the compounds, e.g., amyl cinnamic alcohol, had poorer detection limits
due to larger excess energies and then dissociation to fragments at 200 nm. All the allergens
were measured through a process of nonresonant two-photon ionization using a high-power
laser (130 μJ, 267 nm), the detection limits being below 10 ng/mL. Figure 1 shows the
concentrations of the allergens contained in three commercial fragrances, suggesting that more
than 14 allergens are present in the samples..
14. Tomoko Imasaka, Totaro Imasaka, Spectral Properties of Allergy Substances in Fragrance Calculated for Use in Multiphoton Ionization Mass Spectrometry, 40th International Symposium on Capillary Chromatography and 13th GCxGC Symposium, 2016.05, A variety of chemicals are used as constituents in fragrance. They are contained not only in
perfume but also in numerous cosmetic and household products. Some of them are known to
cause allergy and to degrade a quality of life. According to the statement of the Scientific
Committee on Non-Food Products intended for Consumers (SCCNFP) of the European
Commission in 1999, 26 organic compounds are categorized as fragrance allergens, the
information of which should be provided to consumers of the products [1]. Laser multiphoton
ionization mass spectrometry is an advanced analytical technique for trace analysis of such
substances. It is, however, necessary to know their spectral properties prior to spectrometric
measurements for its successful use.
In this study, ultraviolet-visible (UV-Vis) absorption spectra were calculated for 26 fragrance
allergens including benzyl benzoate (see Fig. 1), linalool, and coumarin from the oscillator
strengths for transitions to the lowest 40 levels of the singlet excited states based on timedependent
density function theory including wB97XD with cc-pVDZ. The vertical ionization
energies (IE) were also calculated from the difference between the energies of the ground and ionic states. The photon energies for excitation to the first excited state (EE) were from 3.59 to 7.14 eV, and the ionization energies from 7.59 to 9.69 eV. These results suggest that 9 and 20 compounds among 26 fragrance allergens can be measured through resonance two-photon ionization using the third (267 nm) and fourth (200 nm) harmonic emissions of a Ti:sapphire laser, respectively..
15. Y. Kida, T. Imasaka, T. Imasaka, Generation of Ultrashort Optical Pulses by Four-Wave Mixing in a Gaseous Medium, The Winter Colloquium on the Physics of Quantum Electronics (PQE), 2016.01.
16. A. Hamachi, T. Imasaka, Y. Mori, V. Duong, Y. Kida, T. Imasaka, Determination of nerve agent metabolites by gas chromatography/multiphoton ionization/time-of-flight mass spectrometry, 2015 International Chemical Congress of Pacific Basin Societies, 2015.12, Nerve agents can easily be decomposed in human body. For example, sarin is decomposed to isopropyl methylphosphonic acid (IMPA) and soman to pinacolyl methylphosphonic acid (PMPA). Mass spectrometry (MS) combined with gas chromatography (GC) or liquid chromatography (LC) has been developed for analysis of nerve agents and their metabolites. In this research, GC coupled with time-of-flight mass spectrometry (TOF-MS) was utilized for analysis of nerve agent metabolites. To derivatize IMPA and PMPA, two types of derivatization methods were used, i.e., pentafluorobenzyl and silyl derivatizations. The derivatized compounds were ionized using two types of femtosecond lasers, i.e., the third and fourth harmonic emissions of a Ti;sapphire laser emitting in the deep-ultraviolet (267 nm) and vacuum-ultraviolet (200 nm) regions, respectively. As recognized from the UV absorption spectra obtained using quantum chemical calculation, the derivatized compounds have the absorption maxima in the vacuum-ultraviolet region. Therefore, the molecules would be ionized through non-resonant two-photon ionization processes at the wavelengths of 200 nm and 267 nm. Molecular ions were observed for IMPA-TBDMS and IMPA-PFB at 267 nm. Only the fragment ions were, however, observed at 200 nm. For PMPA-PFB and PMPA-TBDMS, the fragment ions were measured at all the wavelengths. The two-photon limits for the derivatized compounds were 280 nm, then the fragmentation would dominantly occur due to large excess energies at 200 nm. In addition, the fragmentation would easily occur for the PMPA-derivatized compounds, since PMPA has a larger number of methyl group. It would be desirable to use a vacuum-ultraviolet femtosecond laser for resonance-enhanced two-photon ionization for more efficient ionization..
17. Xixiang Yang, Tomoko Imasaka, Totaro Imasaka, Determination of Hexachlorocyclohexane Isomers by Femtosecond Laser Using Gas Chromatography /Multiphoton Ionization / Mass Spectrometry, The 64th Conference of the Japan Societry for Analytical Chemistry, 2015.09, Hexachlorocyclohexane is one of the most abundant organochlorine pesticide with several isomers. Gas chromatography/time-of-flight mass spectrometry developed in our laboratory was employed, which suggests a new approach for identifying different isomers of chiral pesticides in trace analysis..
18. Tomoko Imasaka, Akifumi Hamachi, Tomoya Okuno, Totaro Imasaka, A simple method for the measurement of the optical pulse width on-site the mass spectrometer, Conference on Lasers and Electro-Optics 2015 (CLEO:2015), 2015.05, The laser pulse width was measured on-site the mass spectrometer by scanning a dispersion in the pulse compressor. A pulse width of 49 fs measured was close to 35 fs calculated from the spectrum..
19. Ryota Ezoe, Tomoko Imasaka, Totaro IMASAKA, Trace analysis of triacetone triperoxide using gas chromatography combined with femtosecond laser ionization mass spectrometry, ISC 2014, Saltburg, Austria, 30th International Symposium on Chromatography, 2014.09.
20. Tomoko Imasaka, Totaro IMASAKA, Spectral properties evaluated using quantum chemical calculation for the measurement of the explosives, ISC 2014 - Salzburg Austria, 30th International Symposium on Chromatography, 2014.09, In recent years, trace analysis of the explosives used in the terrorist attacks has become a priority for homeland security. A technique such as gas chromatography combined with laser multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) has been utilized for detection because of high sensitivity and selectivity [1]. In this study, the ionization condition of the explosives including RDX, TNT, HMTD, PETN, HMX, and TATP were evaluated using quantum chemical calculation for the measurement using GC/MPI/TOF-MS coupled with a femtosecond ionization laser emitting at 267, 241, 219, and 201 nm which can be generated based on four-wave Raman mixing.
Ultraviolet-visible (UV-Vis) absorption spectra were calculated from the oscillator strengths for transitions related to the lowest 40 singlet excitation energies based on time-dependent density function theory (TD-DFT) including B3LYP with cc-pVDZ and cc-pVTZ basis sets. The vertical ionization energies (IE) were also calculated from the difference between the energies of the ground and ionic states. The results of RDX and TNT exhibited a possibility of resonance two-photon ionization with a laser emitting at 241 nm. For HMTD, both resonance two-photon ionization at 219 nm and non-resonance two-photon ionization at 241 nm would be feasible. The results of PETN and TATP showed possibilities of resonance two-photon ionization at 219 nm. As clarified herein, it is necessary to use a femtosecond laser emitting in the deep-UV or vacuum-UV region for efficient ionization the explosives..
21. Yuichiro Kida, Kazuki Sakamoto, Osamu Shitamichi, Tomoya Okuno, Tomoko Imasaka, Totaro IMASAKA, Generation of Numerous Raman Sidebands for Fourier Synthesis of an Ultrashort Optical Pulse beyond the 1-fs Barrier, the 44th Winter Colloquim on the Physics of Quantum Electronics, 2014.01.
22. Tomoya Okuno, Tomoko Imasaka, Yuichiro Kida, Totaro IMASAKA, Mass Spectrometer for Measuring an Autocorrelation Trace of an Ultrashort Optical Pulse in the Ultraviolet Region Based on Two-Photon Ionization of an Organic Compound, The Twelfth Asian Conference on Analytical Sciences, 2013.08.
23. Tomoko Imasaka, Tomoya Okuno, Totaro IMASAKA, Mass Spectrometer for measuring a pulse width of the harmonic emissions of a Ti:sapphire laser based on two-photon excitation and subsequent one photon ionization, 4th Asia Oceania Mass Spectrometry Conference and 10th Taiwan Society for Mass Spectrometry Annual Conference , 2013.07.
24. T. Shimizu, T. Imasaka, S. Zaitsu, T. Uchimura, T. Imasaka, Development of a Laser with an Ultimately-Short Optical Pulse Width for Impulsive Ionization to Obtain a Molecular Ion in Mass Spectrometry, IUPAC International Congress on Analytical Sciences 2011 (ICAS 2011), 2011.05.
25. The theoretical study of the physical property of Triacetonetriperoxide, explosive used for terrorism, Tomoko Imasaka, Hiroko Tsukatani, Takashi Shimizu, Shin-ichi Zaitsu, Tomohiro Uchimura and Totaro Imasaka, The Japan Society of Analytical Chemistry.
26. The data processing technique in Gas Chromatography/Multiphoton Ionization/Time-of-Flight Mass Spectrometry, Tomoko Imasaka, Satoshi Yamaguchi, Tomohiro Uchimura and Totaro Imasaka, The Chemical Society of Japan.
27. The MO study of S1←S0 transition energies and the additivity rule with respect to electron correlation energy of polychlorodibenzofurans, Tomoko Imasaka and Shoji Hirokawa, The Chemical Society of Japan.
28. Ab initio MO study of the structure of S0 and S1 states and S1←S0 transition of Polychlorodibenzofurans(PCDFs), Tomoko Imasaka and Shoji Hirokawa, The Chemical Society of Japan.
29. The theoretical study of the effect of a crystal field and the cavity occupancy on the orientational ordering of SO2- and D2S-β-Quinol Clathrate, Tomoko Imasaka and Shoji Hirokawa, The Chemical Society of Japan.
30. The cavity occupancy and the phase transition of β-Quinol Clathrate, Tomoko Imasaka and Shoji Hirokawa, The Chemical Society of Japan.
31. The orientational ordering and the phase transition of the SO2-β-Quinol clathrate, Tomoko Imasaka and Shoji Hirokawa, The Chemical Society of Japan.
32. The guest-guest interaction and the phase transition of the SO2- and D2S-β-Quinol Clathrate, Shoji Hirokawa and Tomoko Imasaka, The Chemical Society of Japan.
Membership in Academic Society
  • The American Chemical Society
  • The Optical Society (OSA)
  • The Chemical Society of Japan
  • The Japan Society of Applied Physics
  • The Japan Society for Analytical Chemistry
Educational
Other Educational Activities
  • 2017.11.
  • 2016.11.
  • 2014.11.
  • 2013.11.
  • 2012.11.
  • 2011.11.
  • 2010.11.
  • 2009.11.
  • 2008.12.
  • 2007.10.
  • 2006.12.