Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Tomoko Imasaka Last modified date:2019.04.19

Lecturer / Department of Environmental Design / Faculty of Design


Presentations
1. Siddihalu Lakshitha Madunil, Tomoko Imasaka, and Totaro Imasaka, An Ultrashort Ultraviolet Optical Pulse for Ionization of Pesticides in Multiphoton Ionization Mass Spectrometry, The 49th Winter Colloquium on the Physics of Quantum Electronics, 2019.01.
2. Tomoko Imasaka, Totaro Imasaka, How can we detect "Novichok"?, The 49th Winter Colloquium on the Physics of Quantum Electronics., 2019.01.
3. Thang Phan Dinh, Duong Vu, Hiroshi Nakamura, Adan Li, Tomoko Imasaka, Totaro Imasaka, Generation of a Vacuum-Ultraviolet Femtosecond Pulse via Four-Wave Raman Mixing and its Application to Mass Spectrometry, The 49th Winter Colloquium on the Physics of Quantum Electronics., 2019.01.
4. Katsunori Yoshinaga, Tiantian Ju, Tomoko Imasaka,Totaro Imasaka, Design and Construction of Small-Frame Time-of-Flight MassSpectrometer, Symposium on Education and Research for International Collaboration between Kyushu University and National Taiwan Normal University, 2018.10.
5. Fengdan Jin, Tomoko Imasaka, Totaro Imasaka, Analysis of Perfluorocarboxylic Acids by GasChromatography/Multiphoton Ionization/Mass SpectrometryUsing a Femtosecond Laser, Symposium on Education and Research for International Collaboration between Kyushu University and National Taiwan Normal University, 2018.10.
6. Vu Van Son, Tomoko Imasaka, Totaro Imasaka, Determination of Nerve Agent Metabolitesin Human Urine by Ultraviolet Femtosecond Laser IonizationMass Spectrometry Using Derivatization Reaction, Symposium on Education and Research for International Collaboration between Kyushu University and National Taiwan Normal University, 2018.10.
7. Lakshitha Madunil, Tomoko Imasaka, Totaro Imasaka, Analysis of Organochlorine Pesticides Using MultiphotonIonization Time-of-Flight Mass Spectrometry, Symposium on Education and Research for International Collaboration between Kyushu University and National Taiwan Normal University, 2018.10.
8. 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.
9. 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.
10. 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.
11. 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.
12. 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.
13. 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.
14. 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.
15. 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.
16. 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。.
17. 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).
18. 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.
19. 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.
20. 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..
21. 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..
22. 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.
23. 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..
24. Y. Tang, T. Imasaka, S. Yamamoto, T. Imasaka, Time-of-flight mass spectrometry of polycyclic aromatic hydrocarbons and their analogs, 2015 International Chemical Congress of Pacific Basin Societies, 2015.12, Polycyclic aromatic hydrocarbons (PAHs) and their analogs such as nitro-PAHs (NPAHs) and amino-PAHs (APAHs) are present in the atmosphere as environmental pollutants and are proven to have positive correlations with mutagenicity for human beings. To date, many chromatographic techniques such as high-performance liquid chromatography combined with mass spectrometry (HPLC-MS) or gas chromatography combined with mass spectrometry (GC-MS) are the common methods for trace analysis of these compounds [1,2]. However, a novel technique with high sensitivity and selectivity is urgently required especially for the analysis of NPAHs and APAHs, due to low concentrations of these compounds in the environment. In this study, we studied gas chromatography combined with time-of-flight mass spectrometry (GC-TOFMS) using a femtosecond laser as an ionization source for the analysis of NPAHs and APAHs contained in particulate matter 2.5 (PM2.5). The optimal conditions for the analysis of NPAHs were investigated using a tunable femtosecond laser in the spectral region of 405-267 nm. As a result, the subpicogram detection limit was achieved (0.31 pg for 1-NPYR) and the background signals arising from PAHs were suppressed to negligible levels. On the other hand, three APAHs, i.e., 2-aminoanthracene (2-AANTs), 3-aminofluoranthene (3-AFLU), and 1-aminopyrene (2-APYR), were directly analyzed by GC-TOFMS at 267 nm without using pentafluorobenzylidene or N-pentafluorobenzyl-N-heptafluorobutyryl as a derivatizing reagent [2], thus making comprehensive analysis of PAHs, NPAHs, and APAHs possible. Comparing with NPAHs, the lower detection limits were achieved for the above three APAHs (0.16 pg for 1-APYR). Thus, GC-TOFMS has a potential for use in the trace analysis of PAHs and their analogs contained in PM2.5..
25. 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..
26. Yuanyuan Tang, Tomoko Imasaka, Shigekazu Yamamoto, Totaro Imasaka, Multiphoton Ionization of Parent Polycyclic Aromatic Hydrocarbons, Nitrated Polycyclic Aromatic Hydrocarbons and Amino-Polycyclic Aromatic Hydrocarbons, 日本分析化学会第75回分析化学討論会, 2015.05.
27. 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..
28. 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.
29. 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..
30. 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.
31. 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.
32. 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.
33. 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.
34. 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.
35. The reliability evaluation and the measurement of the sample of the soil of laser ionization mass spectrometry in dioxin analysis, Nami Nakamura, Yuka Watanabe-Ezoe, Tomohiro Uchimura, Tomoko Imasaka, Totaro Imasaka, The Japan Society of Analytical Chemistry.
36. The reliability evaluation and measurement of sample of soil of laser ionizaition mass spectrometry in dioxin analysis, Nami Nakamura, Yuka Watanabe-Ezoe, Tomohiro Uchimura, Tomoko Imasaka and Totaro Imasaka, The Japan Society for Analytical Chemistry.
37. 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.
38. Ab initio MO study of the electrical transition energies of PCB, Shoji Hirokawa, Tomoko Imasaka and Totaro Imasaka, The forum of the initiative scientific computation 2006 .
39. Electron Correlation Correction Method to Precisely Compute the (0-0) S1←S0 Transition Energies: Polychlorinated Biphenyls (PCBs), Shoji Hirokawa, Tomoko Imasaka, Yoshikazu Oyakawa, Masataka Oishi, Totaro Imasaka, The 8th Asian conference on Analytical Sciences.
40. 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.
41. The theoretical study of Chlorine Substitution Pattern, Molecular Electronic Properties, and the toxicity of Polychlorinated Dibenzofurans, Shoji Hirokawa and Tomoko Imasaka, The Chemical Society of Japan.
42. Ab initio MO study of S1←S0 transition of PCDD/DFs, Shoji Hirokawa and Tomoko Imasaka, The Chemical Society of Japan.
43. 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.
44. The theoretical study of the effect of host system on the orientational ordering of the guest system of the β-Quinol Clathrate, Tomoko Imasaka and Shoji Hirokawa, The Chemical Society of Japan.
45. The ab initio MO study of S0 and S1 states of Monochlorophenols (1), Shoji Hirokawa, Totaro Imasaka and Tomoko Imasaka, The Chemical Society of Japan.
46. 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.
47. The cavity occupancy and the phase transition of β-Quinol Clathrate, Tomoko Imasaka and Shoji Hirokawa, The Chemical Society of Japan.
48. The orientational ordering and the phase transition of the SO2-β-Quinol clathrate, Tomoko Imasaka and Shoji Hirokawa, The Chemical Society of Japan.
49. The crystal field and the phase transition of the SO2-β-Quinol clathrate, Shoji Hirokawa and Tomoko Imasaka, The physical Society of Japan.
50. 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.
51. The phase transition of three dimensional rotator, Shoji Hirokawa and Tomoko Imasaka, The Physical Society of Japan.
52. The Guest-Guest interaction and the phase transition in the H2S-β-Quinol Clathrate, Shoji Hirokawa and Tomoko Imasaka, the Chemical Society of Japan.
53. The phase transition of H2S-β-Quinol Claslate, Shoji Hirokawa, Tomoko Iwasaki(Imasaka), The Chemical Society of Japan.