レーザーイオン化質量分析
キーワード：質量分析、レーザーイオン化
2006.04.

超短パルス光の発生
キーワード：超短パルス
2008.04.

質量分析計の開発
キーワード：小型質量分析計
2008.04.

令和4年度研究活動基礎支援制度「国際学会派遣支援」
2022.09～2022.10, 代表者：今坂 智子, 九州大学, ベトナム科学技術院、ベトナム物理学会等。組織委員会議長：科学技術省大臣Huynh Thanh Dat、ベトナム物理学会会長Nguyen Dai Hung
The 12th International Conference on Photonics and Applications (ICPA-12) 国際会議では越、日、仏、露をはじめとする各国の研究者の発表によりフォトニクスに関する最先端の知見を得ることができた。招待講演に加えて同学会が出版する学会誌の編集委員会にも各国の代表に交えて出席させていただき、共同研究の可能性を議論するとともに人脈を広げることができた。帰国後すぐにロシアの物理学研究所の教授から来年のモスクワ開催の国際会議の招待講演の依頼をいただいた。また、ハノイやホーチミンのベトナム科学技術院の先生方の研究室を訪ね、共同研究の打ち合わせを行った。.

第38回（2022年度）研究助成（村田学術振興財団）、バイオ燃料の規格、認証のための新規科学計測法の開発
2022.12～2023.11, 代表者：今坂 智子, 九州大学.

天田財団 助成　レーザー加工者の安全と環境を 守るためのオンサイト・リアルタイム計測技術の開発
2021.10～2025.03, 代表者：今坂 智子, 九州大学.

基盤研究(B)「爆発物並びに化学兵器剤の使用者を特定するための新規科学技術の開発」
2020.04～2023.03, 代表者：今坂智子, 九州大学, 日本学術振興会.

中部電力 原子力安全技術研究所公募研究（一般）「災害時に有害な化学物質を測定するための新規計測手段の開発」
2020.09～2022.03, 代表者：今坂智子, 九州大学.

アジア地域重点学術研究助成（平和中島財団）「世界の人々の安全を守る科学計測技術の開発」
2021.04～2022.03, 代表者：今坂智子, 九州大学, 九州大学
アジア地域重点学術研究助成（平和中島財団）に採択され、「世界の人々の安全を守る科学計測技術の開発」の研究をスリランカ政府分析部門 分析官補らの研究者と共に行った.

世界トップレベル研究者招へいプログラム（Progress100）「ランキングトップ100の4大学と実施する科学計測技術に関する国際学術・教育交流 － 台湾大学 、シンガポール大学 、ミュンヘン工科大学、スイス連邦工科大学」
2019.04～2022.03, 代表者：今坂智子, 九州大学, 九州大学
　台湾大学、シンガポール大学 、ミュンヘン工科大学 、スイス連邦工科大学（ ETH-Zurich） と 、世界的に重要な課題である環境汚染物質、薬物、爆発物、神経ガス代謝物などの科学計測に関する学術交流を通して、戦略的かつ継続的な協力体制を構築する。 招へい研究者は 理・ 農・工・薬学を始め幅広い分野に亘る申請者と同一専門分野の質量分析の研究に携わっており 、アジア・欧州 における 諸問題の解決と学術の一層の発展を目指す 。本事業では台湾大学（台湾で第1位）の林金全教授、何佳安教授、林志民教授、 シンガポール大学（アジアで第1位）の Hian Kee Lee 教授、 ミュンヘン工科大学（離脱予定の英国を除くユーロ工学系で第1位）のMartin Elsner教授 、ETH-Zurich （欧州大陸で第1位）のRenato Zenobi教授、Marcy Zeonobi-Wong教授等を招へいして国際共同研究や国際シンポジウム を実施し、 これらの大学との学術交流の拡大に貢献した 。　.

National Taiwan Normal University – Kyushu University 2020 Collaboration Development Fund
2020.04～2022.03, 代表者：今坂智子、Cheng-Huang Lin, 九州大学、National Taiwan Normal University, 九州大学、National Taiwan Normal University (Taiwan)
National Taiwan Normal University – Kyushu University 2020 Collaboration Development Fund（九州大学と台湾師範大学による共同研究）のプロジェクトにおいて”Development of an analytical instrument for determination of acetone in human breadth”の研究を行った.

基盤(C)「テロ関連物質の超高速光イオン化質量分析とそのスペクトルの理論的予測」
2008.04～2011.03, 代表者：今坂智子, 九州大学, 日本学術振興会.

基盤(C)「化学兵器剤の高感度かつ網羅的な測定―量子化学計算による分光学的性質の理論的予測―」
2015.04～2018.03, 代表者：今坂智子, 九州大学, 日本学術振興会.

基盤研究(C)「量子化学計算による理論予測に基づくテロ爆発物の高感度で網羅的な検知」
2012.04～2015.03, 代表者：今坂智子, 九州大学, 日本学術振興会.

第46回 岩谷科学技術研究助成「レーザーイオン化質量分析計の開発と環境汚染物質の一斉分析」
2020.04～2021.03, 代表者：今坂智子, 九州大学, 第46回 岩谷科学技術研究助成.

世界トップレベル研究者招へいプログラム（Progress100）「科学計測技術に関する台湾師範大学との国際共同研究」
2018.04～2019.03, 代表者：今坂智子, 九州大学, 九州大学
　台湾と日本において緊急かつ重要な課題である環境汚染物質、薬物、爆発物、神経ガス代謝物の科学計測に関する技術開発を、九州大学と国立台湾師範大学間の国際共同研究により実施する。とくに両者が世界に誇れる最先端技術であるレーザーイオン化質量分析（LI-MS）の開発を通して、両国の学術研究の一層の発展を促すと共に、その技術の社会実装により両国民の安全、安心に繋げる活動を行った。国立台湾師範大学の林震煌教授、陳准教授、李助教、修士学生を招聘して研究を行った。
(1) 国際シンポジウムの開催と大学間学術・学生交流協定の締結・・台湾師範大学から呉学長など33名、九州大学から久保総長や工学研究院長、役職者など29名をお招きして、九州大学で国際シンポジウム「九州大学と国立台湾師範大学との国際連携のための教育と研究シンポジウム：Symposium on Education and Research for International Collaboration between Kyushu University and National Taiwan Normal University：平成30年10月22日、稲盛ホール、参加者数約61名」を主宰し、九州大学と台湾師範大学間の「大学間学術・学生交流協定」の締結に貢献した。国際シンポジウムでは、九州大学側から理学、工学、教育学など多様な分野の研究者が参加して講演した。また工学研究院、先導物質化学研究所、マスフォアインダストリアル研究所など多くの部局の先生方と協議が行なわれ、今後の共同研究の契機となることが期待されている。このシンポジウムと協定の締結は、九州大学だけでなく台湾師範大学の公式ホームページにおいても詳細に紹介された（http://en.ntnu.edu.tw/news-show.php?id=12390）。　　　
(2) 台湾師範大学が開催するフォーラムへの招へい・・平成31年5月に台湾師範大学主催で「The 2019 National Taiwan Normal University (NTNU) - Kyushu University Joint Forum on Facilitating Interdisciplinary Research and Education」と題するフォーラムが開催される予定である。九州大学から総長をはじめ化学や生物、教育など様々な分野の研究者（代表者を含む）が招へいされて講演すると共に、教育と研究のコラボレーションの強化について討論が行われる予定である。　　　
(3) 第16回台湾質量分析学会・年会への招へい・・平成31年7月に台湾質量分析学会・会長の賴建成教授（国立中興大学）が主催する第16回台湾質量分析学会・年会に代表者及び研究協力者が招へいされ、招待講演及び一般講演を行う予定である。本学会には今回招へいした先生方も参加される予定であり、一層の関係強化が期待される。　　　
(4) 台湾大学とAsianalysis XVへの支援・・アジア諸国が参加する分析科学国際会議”The Asian Conference on Analytical Sciences”の第15回目となる”Asianalysis XV”が2020年に台湾で開催される。本会議開催の代表者である台湾大学の林金全特聘教授及び林震煌教授を含む数名の先生方と会談し、日本が主導して設立した本会議の開催を支援することを約束した。共同研究の可能性についても協議し、今後相互に努力することにした。台湾大学、さらにアジアのトップ100の大学との連携を視野に入れて交流を進めたいと考えている。　　　.

二国間交流事業共同研究（ベトナム）　Analysis of Persistent Organic Pollutants (POPs) in the Environment Using a Femtosecond Laser
2014.04～2016.03, 九州大学, 日本学術振興会(日本）.

土壌中の環境汚染物質の網羅的分析の研究
2010.10～2012.10, 九州大学, (財)鉄鋼業環境保全技術開発基金 研究助成金.

プロジェクト部門・新キャンパス実験感性空間・虹色レーザーディスプレイ
2004.04～2008.03, 九州大学, 科学技術振興機構、九州大学
振興調整費・戦略的研究拠点育成事業・九州大学ユーザーサイエンス機構（ＵＳＩ）.

感性融合技術の創造－学部・大学院の教育研究から最先端技術の開発、ベンチャー設立まで－
2004.04～2006.03, 九州大学, 九州大学
九州大学教育研究プログラム・研究拠点形成プロジェクト（Ｐ＆Ｐ）採択課題.

主要原著論文

1.	Katsunori Yoshinaga, Lu Wen, Totaro Imasaka, and Tomoko Imasaka（責任著者）, Determination of fatty acid methyl esters by two-color two-photon resonance-enhanced femtosecond ionization mass spectrometry, Analytica Chimica Acta, 10.1016/j_aca.2024.342341, 1296, 342341, 2024.02, 2色2光子共鳴増強フェムト秒イオン化質量分析による脂肪酸メチルエステルの定量分析を行った。.
2.	Lu Wen, Katsunori Yoshinaga, Totaro Imasaka, and Tomoko Imasaka（責任著者）, Trace analysis of nitrated polycyclic aromatic hydrocarbons based on two-color femtosecond laser ionization mass spectrometry, Talanta, 10.1016/j.talanta.2023.124807, 265, 124807, 2023.06, ２色のフェムト秒レーザーをイオン化光源としてニトロ多環芳香族の質量分析を行った。.
3.	Siddihalu Lakshitha Madunil, Totaro Imasaka, and Tomoko Imasaka（責任著者）, Determination of Barbiturates by Femtosecond Ionization Mass Spectrometry, Analytical Chemistry, 10.1021/acs.analchem.2c03077, 94, 14691-14698, 2022.11, 向精神薬を対象にフェムト秒レーザーをイオン化光源とした質量分析を行った。.
4.	Katsunori Yoshinaga, Nguyen Van Hao, Totaro Imasaka, Tomoko Imasaka（責任著者）, Miniature Time-of-Flight Mass Analyzer for Use in Combination with a Compact Highly-Repetitive Femtosecond Laser Ionization Source, Analytica Chimica Acta, 10.1016/j.aca.2022.339673, 1203, 339673, 2022.04, コンパクトで高繰り返しのフェムト秒レーザーイオン化源と組み合わせて使用​​するための小型飛行時間型質量分析計.
5.	Siddihalu Lakshitha Madunil, Totaro Imasaka, Tomoko Imasaka（責任著者）, Comprehensive Analysis of Analogs of Amine-Related Psychoactive Substances Using Femtosecond Laser Ionization Mass Spectrometry., Journal of the American Society for Mass Spectrometry., 10.1021/jasms.1c00282, 33, 90-99, 2021.11, フェムト秒レーザーイオン化質量分析を使用したアミン関連向精神薬の類似体の包括的な分析.
6.	Lu Wen, Fengdan Jin, Totaro Imasaka, Tomoko Imasaka（責任著者）, Esterification of perfluorinated carboxylic acids with bromomethyl aromatic compounds for gas chromatography combined with laser ionization mass spectrometry, Journal of Chromatography A, 10.1016/j.chroma.2021.462546, 1656, 462546, 2021.09, レーザーイオン化質量分析と組み合わせたガスクロマトグラフィーのためのブロモメチル芳香族化合物とパーフルオロカルボン酸のエステル化.
7.	Totaro Imasaka, Tomoko Imasaka（責任著者）, Femtosecond Ionization Mass Spectrometry for Chromatographic Detection, Journal of Chromatography A, 10.1016/j.chroma.2021.462023, 1642, 462023, 2021.04, クロマトグラフ法を用いたフェムト秒イオン化質量分光に関する研究を行った。.
8.	Siddihalu Lakshitha Madunil, Totaro Imasaka, Tomoko Imasaka, Suppression of Fragmentation in Mass Spectrometry, Analytical Chemistry, 10.1021/acs.analchem.0c03615, 92, 16016-16023, 2020.12, 質量分析において、フラグメント化を抑制させることは重要である。シスとトランスの4-メチルシクロヘキサノールに対して可変紫外と近赤外フェムト秒レーザー（35 fs）をイオン化光源として用いる研究を行った。.
9.	Thang Phan, Adan Li, Hiroshi Nakamura, Tomoko Imasaka, Totaro Imasaka, Single Photon Ionization Mass spectrometry Using a Vacuum Ultraviolet Femtosecond Laser, Journal of the American Society for Mass Spectrometry, 10.1021/jasms.0c00154, 31, 8, 1730-1737, 2020.07, 真空紫外フェムト秒レーザーを用いた単一光子イオン化質量分析法について研究を行った。.
10.	Ju Tiantian, K. Yoshinaga, T. Imasaka, H. Nakamura, T. Imasaka, Time-correlated Single Ion Counting Mass Spectrometer with Long and Short Time-of-flight Tubes and an Evaluation of its Performance for Use in Trace Analysis of Allergenic Substances, Analytical Sciences (Special Issue), 10.2116/analsci.19SBP03, 36, 5, 539-543, 2020.05, 時間相関単一イオン計数質量分析計とその性能評価に関する研究を行った。.
11.	Yuta Nakano, Tomoko Imasaka, Totaro Imasaka, Generation of a Nearly-Monocycle Optical Pulse in the Near-Infrared Region and Its Use as an Ionization Source in Mass Spectrometry, Analytical Chemistry, 10.1021/acs.analchem.0c00542, 92, 7130-7138, 2020.05, 近赤外領域で最短の光パルスを発生させ、質量分析計のイオン化光源へ応用した成果を発表した。.
12.	Siddihalu Lakshitha Madunil, Totaro Imasaka, Tomoko Imasaka, Resonant and non-resonant femtosecond ionization mass spectrometry of organochlorine pesticides, Analyst, 10.1039/c9an01861a, 145, 777-783, 2019.12.
13.	V. V. Son, H. Nakamura, T. Imasaka, T. Imasaka, Determination of nerve agent metabolites in human urine by femtosecond laser ionization mass spectrometry using 2-(bromomethyl)naphthalene as a derivatizing reagent, Analytica Chimica Acta, 10.1016/j.aca.2019.04.0120, 1069, 82-88, 2019.04.
14.	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, 7, 4886-4893, 2018.04, A standard sample mixture containing 51 pesticides was separated by gas chromatography (GC), and the constituents were identified by mass spectrometry (MS) using femtosecond lasers emitting at 267, 400, and 800 nm as the ionization source. A two-dimensional display of the GC/MS was successfully used for the determination of these compounds. A molecular ion was observed for 38 of the compounds at 267 nm and for 30 of the compounds at 800 nm, in contrast to 27 among 50 compounds when electron ionization was used. These results suggest that the ultraviolet laser is superior to the near-infrared laser for molecular weight determinations and for a more reliable analysis of these compounds. In order to study the conditions for optimal ionization, the experimental data were examined using the spectral properties (i.e., the excitation and ionization energies and absorption spectra for the neutral and ionized species) obtained by quantum chemical calculations. A few molecules remained unexplained by the currently reported rules, requiring additional rules for developing a full understanding of the femtosecond ionization process. The pesticides in the homogenized matrix obtained from kabosu (citrus sphaerocarpa) were measured using lasers emitting at 267 and 800 nm. The pesticides were clearly separated and measured on the two-dimensional display, especially for the data measured at 267 nm, suggesting that this technique would have potential for use in the practical trace analysis of the pesticides in the environment..
15.	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, 10.1021/acs.analchem.8b00125, 90, 4, 2963-2969, 2018.02, The ionization and fragmentation processes were examined for a standard sample mixture containing 16 polycyclic aromatic hydrocarbons (PAHs) and 3 nitro-PAHs (NPAHs) by gas chromatography combined with mass spectrometry (GC/MS) using a femtosecond laser emitting at 400, 800, or 1200 nm as the ionization source. The signal intensities of NPAHs were lower and the fragmentation more extensive compared to those values for PAHs, especially at shorter wavelengths (400 nm). These results can be explained by efficient intersystem crossing to triplet levels and the shorter excited-state lifetimes of neutral NPAHs molecules, compared to the pulse width of the laser. Fragmentation was significantly suppressed by nonresonant multiphoton ionization when a laser emitting at longer wavelengths (1200 nm) was used. This result can be explained by the absorption spectrum of the molecular ion and the excess energy remaining in the ionized state. In fact, there was no absorption band at 1200 nm for the molecular ion, and the excess energy would be minimal when a near-infrared laser is used, which suppresses the fragmentation even for NPAHs. A doubly charged molecular ion was observed for PAHs but not for NPAHs, probably owing to the higher stability of the PAH molecule, the electrons of which are more strongly bound and are more resistive to field ionization. To demonstrate the utility of this technique, the sample extracted from particulate matter 2.5 (PM2.5) emitted from a diesel engine was measured. NPAHs as well as PAHs were clearly determined at 1200 nm, at which the background signal arising from the interference was drastically suppressed..
16.	Takuya Fujii, Tomoko Imasaka, Totaro Imasaka, Use of chemical conversion for determination of nitrated aromatic hydrocarbons using femtosecond ionization mass spectrometry, Analytica Chimica Acta, 10.1016/j.aca.2017.09.049, 996, 48-53, 2017.12, A sample containing nitrated aromatic hydrocarbons (NPAHs) was injected into the sample inlet port of a gas chromatograph (GC), along with hydrazine, a reducing reagent. The analytes that eluted from the GC column were measured by mass spectrometry (MS) using an ultraviolet femtosecond laser as the ionization source. When no reducing reagent was used, large numbers of polycyclic aromatic hydrocarbons (PAHs) including NPAHs were observed in the two-dimensional GC/MS display. In contrast, when hydrazine was present, reduced forms of NPAHs, which included amino PAHs, were detected. When a palladium or platinum catalyst was placed in the GC inlet port, the compounds were further reduced to non-aromatic hydrocarbons. The present approach would be useful for studies to evaluate the chemical reaction that converts the constituents contained in exhaust emitted from a diesel engine. (C) 2017 Elsevier B.V. All rights reserved..
17.	Adan Li, Thang Phan Dinh, Tomoko Imasaka, Totaro Imasaka, Suppression of fragmentation in multiphoton ionization mass spectrometry using a near-infrared femtosecond laser as an ionization source, ANALYST, 10.1039/c7an01172e, 142, 20, 3942-3947, 2017.10, The ionization and fragmentation processes for pentachlorobenzene were examined using a femto-second laser emitting at 400, 800, and 1200 nm. A molecular ion was clearly observed in the mass spectrum, since the molecule can be directly ionized from the singlet electronic exited state before relaxation to triplet levels, because the pulse width of the laser is shorter than the lifetime of the excited state. Fragmentation was minimal at 1200 nm, in contrast to ionization at 800 and 400 nm. Indeed, a doubly-charged molecular ion was prominent at 800 nm, owing to the absorption band of the singly-charged molecular ion at this wavelength. Fragmentation was further enhanced at 400 nm, which can be explained by the dissociation of the doubly-charged molecular ion having a larger absorption band at 400 nm. Fragmentation was strongly affected by the absorption character of the ionic species, i.e., singly and doubly-charged molecular ions, appeared in the process of multiphoton ionization..
18.	Akifumi Hamachi, Tomoko Imasaka, Hiroshi Nakamura, Adan Li, Totaro Imasaka, Determination of Nerve Agent Metabolites by Ultraviolet Femtosecond Laser Ionization Mass Spectrometry, ANALYTICAL CHEMISTRY, 10.1021/acs.analchem.7b00386, 89, 9, 5030-5035, 2017.05, Nerve agent metabolites, i.e., isopropyl methylphosphonic acid (IMPA) and pinacolyl methylphosphonic acid (PMPA), were derivatized by reacting them with 2,3,4,5,6-pentafluorobenzyl bromide (PFBBr) and were determined by mass spectrometry using an ultraviolet femtosecond laser emitting at 267 and 200 nm as the ionization source. The analytes of the derivatized compounds, i.e., IMPA-PFB and PMPA-PFB, contain a large side-chain, and molecular ions are very weak or absent in electron ionization mass spectrometry. The use of ultraviolet femtosecond laser ionization mass spectrometry, however, resulted in the formation of a molecular ion, even for compounds such as these that contain a highly bulky functional group. The signal intensity was larger at 200 nm due to resonance-enhanced two-photon ionization. In contrast, fragmentation was suppressed at 267 nm (nonresonant two-photon ionization) especially for PMPA-PFB, thus resulting in a lower background signal. This favorable result can be explained by the small excess energy in ionization at 267 nm and by the low-frequency vibrational mode of a bulky trimethylpropyl group in PMPA..
19.	Xixiang Yang, Tomoko Imasaka, Adan Li, Totaro Imasaka, Determination of Hexachlorocyclohexane by Gas Chromatography Combined with Femtosecond Laser Ionization Mass Spectrometry, JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY, 10.1007/s13361-016-1497-7, 27, 12, 1999-2005, 2016.12, Structural isomers and enantiomers of hexachlorocyclohexane (HCH) were separated using a chiral column by gas chromatography and quantitatively determined by multiphoton ionization mass spectrometry using an ultraviolet femtosecond laser (200 and 267 nm) as the ionization source. The order of elution of the enantiomers (i.e., (+)-alpha-HCH and (-)-alpha-HCH) was predicted from stabilization energies calculated for the complexes using permethylated gamma-cyclodextrin as the stationary phase of the column, and the results were compared with the experimental data. The molecular ions observed for HCH were weak, even though they can be ionized through a process of resonance enhanced two-photon ionization at 200 nm. This unfavorable result can be attributed to the dissociation of the molecular ion, as predicted from quantum chemical calculations..
20.	Shimpei Shibuta, Tomoko Imasaka, Totaro Imasaka, Determination of Fragrance Allergens by Ultraviolet Femtosecond Laser Ionization Mass Spectrometry, ANALYTICAL CHEMISTRY, 10.1021/acs.analchem.6b03229, 88, 21, 10693-10700, 2016.11, The allergenic compounds listed in the Cosmetics Directive by the Scientific Committee for Consumer Safety were analyzed by gas chromatography combined with multiphoton ionization mass spectrometry using a femtosecond laser emitting at 200 and 267 nm as the ionization source. The limits of detection were less than 100 pg/mu L for all of the compounds, permitting them to be measured in actual samples that were simply prepared by a 100-fold dilution of the original sample. The ionization process was investigated for the 26 allergens, some of which had no absorption band, even in the far-UV region. As a result, nonresonant two-photon ionization was found to be the most sensitive and universal method for the trace analysis of these compounds, because of the short pulse width, i.e., a high peak power, of the femtosecond laser used. It should be noted that the excess energy can be reduced by using a laser emitting at longer wavelengths (267 nm) and that fragmentation can be suppressed, especially for a molecule that contains a long side chain. Three commercially available perfumes were measured, and more than 10 allergenic compounds were determined..
21.	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, 10.1016/j.chemosphere.2016.02.114, 152, 252-258, 2016.06, Multiphoton ionization processes of parent-polycyclic aromatic hydrocarbons (PPAHs), nitro-PAHs (NPAHs), and amino-PAHs (APAH5) were examined by gas chromatography combined with time-of-flight mass spectrometry using a femtosecond Ti:sapphire laser as the ionization source. The efficiency of multiphoton ionization was examined using lasers emitting in the far-ultraviolet (200 nm), deep ultraviolet (267 nm), and near-ultraviolet (345 nm) regions. The largest signal intensities were obtained when the far-ultraviolet laser was employed. This favorable result can be attributed to the fact that these compounds have the largest molar absorptivities in the far-ultraviolet region. On the other hand, APAH5 were ionized more efficiently than NPAHs in the near-ultraviolet region because of their low ionization energies. A sample extracted from a real particulate matter 2.5 (PM2.5) sample was measured, and numerous signal peaks arising from PAH and its analogs were observed at 200 nm. On the other hand, only a limited number of signed peaks were observed at 345 nm, some of which were signed to PPAHs, NPAHs, and APAHs. Thus, multiphoton ionization mass spectrometry has potential for the use in comprehensive analysis of toxic environmental pollutants. (C) 2016 Elsevier Ltd. All rights reserved..
22.	Tomoko Imasaka, Akifumi Hamachi, Tomoya Okuno, Totaro Imasaka, A Simple Method for the Evaluation of the Pulse Width of an Ultraviolet Femtosecond Laser Used in Two-Photon Ionization Mass Spectrometry, APPLIED SCIENCES-BASEL, 10.3390/app6050136, 6, 5, 2016.05, A simple method was proposed for on-site evaluation of the pulse width of an ultraviolet femtosecond laser coupled with a mass spectrometer. This technique was based on measurement of a two-photon ionization signal in mass spectrometry by translation of the prism in the pulse compressor of the femtosecond laser. The method was applied to optical pulses that were emitted at wavelengths of 267, 241, and 219 nm; the latter two pulses were generated by four-wave Raman mixing using the third harmonic emission of a Ti:sapphire laser (267 nm) in hydrogen gas. The measurement results show that this approach is useful for evaluation of the pulse width of the ultraviolet femtosecond laser used in mass spectrometry for trace analysis of organic compounds..
23.	Vu Thi Thuy Duong, Vu Duong, Nghiem Thi Ha Lien, Tomoko Imasaka, Yuanyuan Tang, Shinpei Shibuta, Akifumi Hamachi, Do Quang Hoa, Totaro 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, 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. (C) 2015 Elsevier B.V. All rights reserved..
24.	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, 10.1007/s13361-015-1276-x, 27, 2, 293-300, 2016.02, Particulate matter 2.5 (PM2.5), collected from ambient air in Fukuoka City, was analyzed by gas chromatography combined with multiphoton ionization mass spectrometry using an ultraviolet femtosecond laser (267 nm) as the ionization source. Numerous parent polycyclic aromatic hydrocarbons (PPAHs) were observed in a sample extracted from PM2.5, and their concentrations were determined to be in the range from 30 to 190 pg/m(3) for heavy PPAHs. Standard samples of nitrated polycyclic aromatic hydrocarbons (NPAHs) were examined, and the limits of detection were determined to be in the picogram range. The concentration of NPAH adsorbed on PM2.5 in the air was less than 900-1300 pg/m(3)..
25.	Yuanyuan Tang, Tomoko Imasaka, Shigekazu Yamamoto, Totaro Imasaka, Multiphoton ionization mass spectrometry of nitrated polycyclic aromatic hydrocarbons, TALANTA, 10.1016/j.talanta.2015.03.027, 140, 109-114, 2015.08, In order to suppress the fragmentation and improve the sensitivity for determination of nitrated polycyclic aromatic hydrocarbons (NPAHs), the mechanism of multiphoton ionization was studied for the following representative NPAHs, 9-nitroanthracene, 3-nitrofluoranthene, and 1-nitropyrene. The analytes were extracted from the PM2.5 on the sampling filter ultrasonically, and were measured using gas chromatography/multiphoton ionization/time-of-flight mass spectrometry with a femtosecond tunable laser in the range from 267 to 405 nm. As a result, a molecular ion was observed as the major ion and fragmentation was suppressed at wavelengths longer than 345 nm. Furthermore, the detection limit measured at 345 nm was measured to be the subpicogram level. The organic compounds were extracted from a 2.19 mg sample of particulate matter 2.5 (PM2.5), and the extract was subjected to multiphoton ionization mass spectrometry after gas chromatograph separation. The background signals were drastically suppressed at 345 nm, and the target NPAHs, including 9-nitroanthracene and 1-nitropyrene, were detected, and their concentrations were determined to be 5 and 3 pg/m(3), respectively. (C) 2015 Elsevier B.V. All rights reserved..
26.	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-BASEL, 10.3390/app5020136, 5, 2, 136-144, 2015.06, A gas was utilized in producing the third harmonic emission as a nonlinear optical medium for autocorrelation and frequency-resolved optical gating measurements to evaluate the pulse width and chirp of a Ti:sapphire laser. Due to a wide frequency domain available for a gas, this approach has potential for use in measuring the pulse width in the optical (ultraviolet/visible) region beyond one octave and thus for measuring an optical pulse width less than 1 fs..
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, 2015 Conference on Lasers and Electro-Optics (CLEO), JTu5A.7, 2015.05.
28.	Akifumi Hamachi, Tomoya Okuno, Tomoko Imasaka, Yuichiro Kida, Totaro Imasaka, Resonant and Nonresonant Multiphoton Ionization Processes in the Mass Spectrometry of Explosives, ANALYTICAL CHEMISTRY, 10.1021/ac504667t, 87, 5, 3027-3031, 2015.03, Multiphoton ionization processes were studied for three types of explosives using a line-tunable ultraviolet femtosecond laser. When peroxides such as triacetone triperoxide (TATP) and hexamethylene triperoxide diamine (HMTD) were ionized through a nonresonant two-photon process, a molecular ion was dominantly observed by reducing the excess energy remaining in the ion. However, an aromatic nitro compound such as 2,4,6-trinitrotoluene (TNT) produced large signals arising from molecular and fragment ions by resonant two-photon ionization. In addition, only fragment ions were produced from a nonaromatic nitro compound such as 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), even when a resonant two-photon ionization process was employed, suggesting that a further reduction in excess energy would be necessary if a molecular ion were to be observed..
29.	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, 2015.01, Triacetone triperoxide (TATP), an explosive compound, was measured using gas chromatography combined with multiphoton ionization time-of-flight mass spectrometry (GC/MPI-TOFMS). By decreasing the pulse width of a femtosecond laser from 80 to 35 fs, a molecular ion was drastically enhanced and was measured as one of the major ions in the mass spectrum. The detection limits obtained using the molecular (M center dot+) and fragment (C2H3O+) ions were similar or slightly superior to those obtained using conventional mass spectrometry based on electron and chemical ionization. In order to improve the reliability, an isotope of TATP, i.e., TATP-d18, was synthesized and used as an internal standard in the trace analysis of TATP in a sample of human blood. TATP could be identified in a two-dimensional display, even though numerous interfering compounds were present in the sample. Acetone, which is frequently used as a solvent in sampling TATP, produced a chemical species with a retention time nearly identical to that of TATP and provided a C2H3O+ fragment ion that was employed for measuring a chromatogram of TATP in conventional MS. This compound, the structure of which was assigned as phorone, was clearly differentiated from TATP based on a molecular ion observable in MPI-TOFMS. (C) 2014 Elsevier B.V. All rights reserved..
30.	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, Excitation energies, oscillator strengths, and vacuum-ultraviolet/deep-ultraviolet absorption spectra were calculated for nerve agents, such as sarin, soman, VX, tabun, mustard gas, and analogs. We used time-dependent density functional theory (TD-DFT) methods that included B3LYP combined with basis sets of cc-pVDZ and cc-pVTZ, and omega B97XD with cc-pVTZ. The vertical ionization energies were also calculated for these compounds, in order to collect additional information relative to the optimal pathways for multiphoton ionization in mass spectrometry..
31.	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, An autocorrelator consisting of a time-of-flight mass spectrometer as a two-photon-response detector was constructed for use in measuring an optical pulse width based on non-resonant two-photon ionization. An organic compound that can be two-photon ionized in a wide spectral region has the potential for use in measuring an optical pulse width approaching 1 fs. (C) 2013 Elsevier B.V. All rights reserved..
32.	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, 2013.12, 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 two-photon-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..
33.	Tomoko Imasaka, Totaro Imasaka, Searching for a molecule with a wide frequency domain for non-resonant two-photon ionization to measure the ultrashort optical pulse width, OPTICS COMMUNICATIONS, 10.1016/j.optcom.2012.04.015, 285, 16, 3514-3518, 2012.07, 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. (C) 2012 Elsevier B.V. All rights reserved..
34.	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.
35.	Osamu Shitamichi, Tomoko Imasaka, Tomohiro Uchimura, Totaro Imasaka, Multiphoton ionization/mass spectrometry of polybrominated diphenyl ethers, ANALYTICAL METHODS, 10.1039/c1ay05355h, 3, 10, 2322-2327, 2011.10, Gas chromatography combined with multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) using ultraviolet picosecond and femtosecond lasers was employed to quantitatively analyze a series of polybrominated diphenyl ethers (PBDEs). Congeners from monoBDE to tetraBDEs were analyzed using a picosecond laser emitting at 266 nm. In order to enhance the efficiency of ionization for highly brominated DEs via triplet levels, a different laser emitting at 213 nm was used. It was, however, difficult to quantify such congeners, even at this wavelength. This unexpected result can be explained by the photodecomposition of PBDEs from the triplet levels. On the other hand, all congeners from monoBDE to decaBDE were detected when a femtosecond laser emitting at 267 nm was employed. Interestingly, the isomers having a smaller number of Br atoms at the meta-positions were more efficiently ionized, and provided lower values of detection limit..
36.	Adan Li, Tomoko Imasaka, Tomohiro Uchimura, Totaro Imasaka, Analysis of pesticides by gas chromatography/multiphoton ionization/mass spectrometry using a femtosecond laser, ANALYTICA CHIMICA ACTA, 10.1016/j.aca.2011.06.003, 701, 1, 52-59, 2011.09, Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOFMS) was utilized for analysis of a standard mixture sample containing 49 pesticides and 4 real samples using the third-harmonic emission (267 nm) of a femtosecond Ti:sapphire laser (100 fs) as the ionization source. A sample of a standard mixture of n-alkane was also measured for calibration of the retention time indices of the pesticides. Two photons are required for the excitation of n-alkane due to an absorption band located in the far ultraviolet region (140 nm). The n-alkane molecule in the excited state was subsequently ionized either directly or by absorbing another photon because of a high ionization potential. Due to a large excess of energy, the molecular ion was decomposed and formed many fragment ions. Compared to n-alkanes, most of the pesticides were softly ionized by the femtosecond laser: one photon was used for excitation and another was used for the subsequent ionization. The pesticides with no conjugated double bond had a lower ionization efficiency. The present analytical instrument was applied to several samples prepared from a variety of vegetables and a single fruit after pretreatment with solid-phase extraction. Three pesticides were found in these samples, although some of them were not detected by conventional GC/EI/MS-MS due to insufficient sensitivity and selectivity. (C) 2011 Elsevier B.V. All rights reserved..
37.	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, 10.1021/ac1009063, 82, 15, 6519-6525, 2010.08, Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) was developed for trace analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). The use of an ultraviolet femtosecond laser (266 nm) allowed the sensitive, as well as selective, determination of PCDD/Fs with short singlet-excited-state lifetimes; the detection limit was 19 fg for 1,3,6,8-tetraCDF. Performance of the analytical instrument was examined and was ascertained to be satisfactory for all the criteria (K0311) prescribed by the Japanese Industrial Standards (JIS). The relative ionization efficiencies of C-12-native PCDD/Fs against C-13-labeled PCDD/Fs were 1.002 +/- 0.012. This suggests that C-13-labeled isotopes can be used as internal standards with no intensity calibration and that the concentrations of PCDD/Fs can be determined to within an error of ca. 1%. In addition, multiphoton ionization provides negligible levels of background interference for the real soil samples even with curtailed pretreatment. The toxicity equivalence (TEQ) of the real sample was determined using GC/MPI/TOF-MS for performance evaluation against high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). The results suggest equivalent or even superior performance for GC/MPI/TOF-MS, due to low background interference and to the ability to check the reliability of the assignment from the intensity distribution of the isotope peaks..
38.	Takashi Shimizu, Yuka Watanabe-Ezoe, Satoshi Yamaguchi, Hiroko Tsukatani, Tomoko Imasaka, Shin-ichi Zaitsu, Tomohiro Uchimura, Totaro Imasaka, Enhancement of Molecular Ions in Mass Spectrometry Using an Ultrashort Optical Pulse in Multiphoton Ionization, ANALYTICAL CHEMISTRY, 10.1021/ac1003773, 82, 9, 3441-3444, 82, 3441-3444, 2010.05, The spectral domain of an ultraviolet femtosecond laser was expanded by stimulated Raman scattering/four-wave Raman mixing, and the resulting laser pulse was compressed using a pair of gratings. The pulse width was then measured using an autocorrelator comprised of a Michelson interferometer equipped with a multiphoton ionization/mass spectrometer which was used as a two-photon detector. A gas chromatograph/mass spectrometer was employed to analyze triacetone triperoxide (TATP), and the molecular ion induced by multiphoton ionization was substantially enhanced by decreasing the laser pulse width..
39.	Shoji Hirokawa, Tomoko Imasaka, Totaro Imasaka, The S-1 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, This paper reexamines the structures and energies of dibenzofuran and twenty PCDFs in S-1-S-3 states. It was demonstrated that, although the CIS method gives a false relative ordering of excited states, the false ordering can be remedied by the CIS(D) method. Moreover the CIS geometries of typical PCDF molecules reasonably agree with their SAC-CI geometries. It was found that molecules chlorinated at the 1- and 9-positions are twisted in the S-2 state but are planar in other states, except for 1,4,6,9-TeCDF and fully chlorinated dibenzofuran (OCDF). The twisted structure of 1,4,6,9-TeCDF occurs in the S-3 state, but the structure of OCDF is twisted in every state. We partitioned the molecule into the parent structure and four chlorine groups and measured the twist energy with reference to the ground state. Then, the S-1
40.	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, Triacetone triperoxide (TATP), which is used as an explosive in acts of terrorism, was measured by means of gas chromatography/multiphoton ionization/time-of-flight mass spectrometry using a deep-ultraviolet (deep-UV) femtosecond laser as an ionization source. The fragmentation process was investigated by changing the intensity of the laser at the center axis of a molecular beam. A molecular ion was observed using a femtosecond laser, and the ratio of the intensities of the molecular and fragment ions decreased as the intensity of the laser increased. These results suggest that TATP can be efficiently ionized using a deep-UV, ultrashort optical pulse. Furthermore, fragmentation was accelerated by excess energy supplied through higher-order multiphoton processes under a strong radiation field. The detection limits obtained using the molecular ion and two dominant fragment ions, C(2)H(3)O(+) + and CH(3)(+) were determined to be 670, 83 and 150 pg, respectively. Copyright (C) 2009 John Wiley & Sons, Ltd..
41.	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, A Supersonic jet/resonance-enhanced multiphoton ionization/time-of-flight mass spectrum (SSJ/REMPI/TOF-MS) was measured for xylenols and ethylphenols. Sharp and intense peaks were observed in the REMPI spectrum of 2,4-xylenol. and the wavelength of the peak tentatively assigned to the 0-0 transition was the longest among xylenols and ethylphenols. These results suggest that 2,4-xylenol, designated as a Class 11 chemical Substance in the Pollutant Release and Transfer Register (PRTR), can be measured sensitively and selectively even when numerous isomers are Present in the sample..
42.	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.
43.	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, 632, 2, 229-233, Volume: 632 Issue: 2 Pages: 229-233, 2009.01, Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) was applied to the trace analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). To determine the optimum wavelength for analysis of PCDD/Fs, the wavelength of the femtosecond laser utilized for multiphoton ionization was converted to near-ultraviolet status using stimulated Raman scattering. A femtosecond laser emitting at 300nm completely eliminated the background signal arising from the bleeding compounds generated from a stationary phase of the capillary column in GC. (C) 2008 Elsevier B.V. All rights reserved..
44.	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.
45.	Tomoko Imasaka, Shoji Hirokawa, Totaro Imasaka, Ab initio MO study on the S-1 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, The geometries and energies for the So and S, states of dibenzoftiran (DF) and all 135 PCDFs were obtained using Hartree-Fock (HF) and CI-Singles (CIS) methods. The transition energies determined from HF and CIS energies were corrected for electron correlation. If the electron correlation energies for the So and the S, state are calculated using a second-order Moller-Plesset perturbation (MP2) and a perturbative correction to CIS (termed CIS(D)) method, the S-1
46.	Shoji Hirokawa, Tomoko Imasaka, Yoshikazu Oyakawa, Masataka Oishi, Totaro Imasaka, Conformational changes and S-1 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, Geometries and S-1
47.	S Hirokawa, T Imasaka, T 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, 10.1021/tx049874f, 18, 2, 232-238, Volume: 18 Issue: 2 Pages: 232-238, 2005.02, It was confirmed that both quadrupole moments and polarizabilities of polychlorinated dibenzofurans (PCDFs), which were calculated using Hartree-Fock theory and/or density functional theory, change systematically with the chlorination pattern governing molecular charge distribution. A mathematical model based on ligand-receptor binding and solute-solvent interaction is reported to explain the difference in toxicity between PCDFs. Multiple regression analysis demonstrated that the difference in the potency of aryl hydrocarbon hydroxylase (AHH) and 7-ethoxyresorufln O-deethylase (EROD) inductions is mostly determined by the polarizabilities of PCDFs. This suggests that the interaction of a PCDF with the aryl hydrocarbon receptor (AhR) and its interaction with surrounding molecules in the cytosol are dispersion interactions rather than electrostatic interactions. Quadrupole moment, electron affinity, and absolute hardness do not appear to be significantly correlated with the differences in AHH and EROD activities among PCDFs. The entropy change of dissolution is important in predicting the AHH and EROD activities with good accuracy. A mathematical model is also used to study the differences in AhR binding between PCDFs..
48.	Tomoko Imasaka, Shoji Hirokawa, Additivity of electron correlation energy and the ab initio MO calculation of (0-0) S1 ←S0 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, The energies of the S0and S1states of polychlorinated dibenzofurans (PCDFs) were calculated using the Hartree-Fock (HF) and configuration interaction-singles (CIS) methods. We can obtain the (0-0) transition energies of PCDFs with good accuracy if the energies calculated using the HF and CIS methods are adjusted to take the electron correlation energy into account. The correlation energy of the S0state was calculated using the Møller-Plesset correlation correction truncated at the second order (MP2), and that of the S1state was determined using experimental data. The correlation energies for both S0and S1states were expressed as the sum of the contributions arising from dibenzofuran (DF) and substituted chlorine atoms. The energy of the ground state calculated using the additivity approximation was in good agreement with the energy given directly by the MP2 method. The (0-0) S1←S0transition energies corrected for electron correlation energy agreed well with the available experimental data. The approach proposed in this paper may be useful for the estimation of the electronic transition energy for large aromatic molecules. © 2004 Elsevier B.V. All rights reserved..
49.	Shoji Hirokawa, Tomoko Imasaka, Yoshihiro Urakami, Ab initio MO study on the S1 ← S0 transitions of polychlorinated dibenzo-p-dioxins, Journal of Molecular Structure: THEOCHEM, 10.1016/S0166-1280(02)00648-6, 622, 3, 229-237, Volume: 622 Issue: 3 Pages: 229-237, 2003.03, The optimized geometries for the S0and S1states of dibenzo-p-dioxin and eight polychlorinated dibenzo-p-dioxins (PCDDs) were obtained by using HF, B3LYP, or CIS methods. Calculated results were in good agreement with available X-ray crystallographic structures. The effects of substituent chlorine atoms and electronic excitation on the molecular geometries are discussed. The correlation energy was estimated by a comparison of (0-0) transition energies, calculated using HF and CIS methods, with observed energies. It was confirmed that the correlation energy of PCDD was primarily caused by the electrons belonging to the benzene and central rings, and that substituted chlorine atoms made a relatively small contribution to the correlation energy. The correction for the correlation energy demonstrated that it was possible to make (0-0) transition energies agree with experimental energies within an error of 2%. Electronic spectra were also studied on the basis of INDO/S calculations. © 2003 Elsevier Science B.V. All rights reserved..
50.	S Hirokawa, T Imasaka, T Imasaka, S-0 and S-1 states of monochlorophenols: Ab initio CASSCF MO study, JOURNAL OF PHYSICAL CHEMISTRY A, 10.1021/jp011533c, 105, 40, 9252-9257, Volume: 105 Issue: 40 Pages: 9252-9257, 2001.10, Optimized geometries and total energies for the So and S, states of five monochlorophenols and phenol were calculated using a 10-electron, 8-orbital CASSCF/6-31G(d). We investigated the effects of a substituent chlorine atom and the S-1
51.	Tomoko Imasaka, Shoji Hirokawa, Mean-field theory of the orientational ordering of dipolar guest molecules in β-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, A clathrate consists of both a 'host' system and a 'guest' system composed of the enclosed molecules. Treating the guest system as a diluted dipolar one, we have investigated the effects on orientational phase transitions of the cavity occupancy cursive Greek chi. a crystal field W due to host molecules, the difference between atom-atom potentials and the ignorance of those contributions by the host system which are not involved in W. It is shown that self-consistency makes the transition temperature Tc a nonlinear function of cursive Greek chi. The occurrence of a successive phase transition is shown to depend on the higher order terms of W and on the difference in the potential model. It is also clarified that the host system may affect, the estimation of Tc. We have further investigated to what extent classical statistical mechanics is applicable at low temperatures. Results are discussed in relation to the experiments..
52.	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.
53.	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.
54.	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.
55.	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.

主要総説, 論評, 解説, 書評, 報告書等

1.	Totaro Imasaka, Tomoko Imasaka, Femtosecond Ionization Mass Spectrometry for Chromatographic Detection, Journal of Chromatography A, 10.1016/j.chroma.2021.462023, 2021.05, クロマトグラフ法を用いたフェムト秒イオン化質量分光に関する研究を行い、総説を掲載した。.
2.	Tomoko Imasaka, Totaro Imasaka, 有害な有機化合物の量子化学計算とそのレーザー分光計測への応用 Quantum chemical calculation and its application to laser spectrometry of hazardous organic compounds, 九州大学中央分析センター報告　第33号 Report of the center of advanced instrumental analysis Kyushu university, No.33, pp.1-8, 2016.02.
3.	廣川昭二, 今坂智子, 大石正高, 親川仁和, スペクトラム算定, 2003.02.
4.	今坂智子、廣川昭二, 二酸化硫黄－ヒドロキノン包接化合物における双極子・双極子相互作用と相転移, 日本化学会有機結晶部会ニュースレター、7, 140-147 (2000), 九州芸術工科大学情報処理センター年報、18, 7-14 (1999)より転載, 2000.07.

主要学会発表等

1.	Tomoko Imasaka and Totaro Imasaka, Forensic and Environmental Analysis Using Femtosecond Laser Ionization Mass Spectrometry, ASIANALYSIS XVI 2023, 2023.10.
2.	吉永 勝法、今坂藤太郎、今坂智子, フェムト秒レーザーを光源とする共鳴２色２光子イオン化法によるアセトンの質量分析, 日本分析化学会第72年会, 2023.09.
3.	Lu Wen、今坂 藤太郎、今坂智子, ニトロ芳香族化合物のフェムト秒レーザーイオン化質量分析：２色ポンプ－プローブ法による励起寿命の測定とその応用, 日本分析化学会第72年会, 2023.09.
4.	今坂 智子、Siddihalu Lakshitha Madunil、今坂 藤太郎, バルビツール酸系のフェムト秒レーザーイオン化質量分析とそのイオン化過程の研究, 日本分析化学会第72年会, 2023.09.
5.	今坂智子, レーザーイオン化質量分析の開発と応用, 日本学術振興会 R026先端計測技術の将来設計委員会 第11回研究会, 2022.12, レーザーをイオン化光源とした共鳴イオン化、非共鳴イオン化の過程や、爆発物、アレルギー物質、環境汚染物質などへの応用、超短パルス光の発生、および小型の質量分析計の開発などの講演を行った。.
6.	Yuta Nakano, Katsunori Yoshinaga, Totaro Imasaka, and Tomoko Imasaka, Generation of an Ultrashort Optical Pulse in the Near-Infrared and Ultraviolet Regions and Mass Spectrometry Using an Ultrashort Optical Pulse as the Ionization Source, NTNU-Kyushu University Joint Forum（国立台湾師範大学と九州大学のジョイントシンポジウム）, 2022.11.
7.	小野原 千聖、吉永 勝法、今坂 藤太郎、今坂智子, 小型サブナノ秒レーザーをイオン化光源とする実用的な飛行時間型質量分析計の開発と応用, 日本分析化学会第71年会, 2022.09.
8.	Tomoko Imasaka, Totaro Imasaka, Development of a Miniature Time-of-Flight Mass Analyzer for Combination with a Highly-Repetitive Femtosecond Laser Source and a Time-Correlated Single Ion Counting System, The 12th International Conference on Photonics and Applications　（招待講演）, 2022.09, [URL], 取得した特許の技術を用いた高繰返しフェムト秒レーザーと時間相関イオン計数装置を用いた飛行時間型質量分析計の開発に関して講演を行った。.
9.	Tomoko Imasaka, Totaro Imasaka, Generation of an Ultrashort Optical Pulse in the Near-Infrared and Vacuum-Ultraviolet Regions for Use as the Ionization Source in Mass Spectrometry, The 12th International Conference on Photonics and Applications　（招待講演）, 2022.09, [URL], 質量分析のイオン化光源として用いるため近赤外領域と真空紫外領域での超短パルス光の発生の研究について発表した。.
10.	今坂智子, 災害時に有害な化学物質を測定するための新規計測手段の開発, 中部電力原子力安全技術研究所 2022年度研究発表会, 2022.07.
11.	L. Wen, K. Yoshinaga, T. Imasaka, T. Imasaka, Femtosecond laser ionization mass spectrometry of nitro polycyclic aromatic hydrocarbons in the ultraviolet, 第82回分析化学討論会, 2022.05.
12.	K. Yoshinaga, T. Imasaka, T. Imasaka, Compact Mass Analyzer for Application to Laser Ionization Mass Spectrometry, Asian Conference on Analytical Sciences XV (ASIANALYSIS XV)　（招待講演）, 2021.10.
13.	Lu Wen, T. Imasaka, T. Imasaka, Derivatization of Perfluorinated Carboxylic Acids for Gas Chromatography Combined with Laser Ionization Mass Spectrometry, Asian Conference on Analytical Sciences XV (ASIANALYSIS XV), 2021.10.
14.	K. Yoshinaga, T. Imasaka, T. Imasaka, On-line Monitoring of Acetone in the Air Using Femtosecond Laser Ionization Mass Spectrometry, Asian Conference on Analytical Sciences XV (ASIANALYSIS XV), 2021.10.
15.	Y. Nakano, T. Imasaka, T. Imasaka, Generation of the Shortest Optical Pulse in the Near Infrared and its Application to the Ionization Source in Mass Spectrometry, Asian Conference on Analytical Sciences XV (ASIANALYSIS XV)　基調講演, 2021.10, 近赤外に置いて最短のパルスを発生させ質量分析計のイオン化光源として応用した.
16.	中野雄太、今坂智子、今坂藤太郎, 近赤外超短パルス光の発生とこれをイオン化光源とする質量分析の研究, 日本分析化学会 第70年会, 2021.09.
17.	吉永勝法、今坂智子、今坂藤太郎, 時間相関単一イオン計数法に基づくフェムト秒Ybレーザーイオン化／超小型飛行時間型質量分析計の開発, 日本分析化学会 第70年会, 2021.09.
18.	Lu Wen, Fengdan Jin, Totaro Imasaka, Tomoko Imasaka, Benzyl esterification of perfluoroalkyl carboxylic acids for gas chromatography combined with laser ionization mass spectrometry, 日本分析化学会 第70年会, 2021.09.
19.	Thang Dinh Phan、Adan Li、中村博、今坂智子、今坂藤太郎, 真空紫外フェムト秒光パルスの発生とこれをイオン化光源とするアミノ多環芳香族化合物の質量分析, 日本分析化学会 第70年会, 2021.09.
20.	Y. Nakano, T. Imasaka, T. Imasaka, Generation of a Nearly-Monocycle Optical Pulse in the Near-Infrared Region and Its Application to Mass Spectrometry, Conference on Lasers and Electro-Optics 2021 (CLEO 2021), 2021.05, 近赤外領域で最短パルスの発生と質量分析計のイオン化源としても応用を行った。.
21.	T. Ju, K. Yoshinaga, T. Imasaka, H. Nakamura, T. Imasaka, Time-correlated Single Ion Counting Mass Spectrometer with Long and Short Time-of-flight Tubes and the Use in Trace Analysis of Allergenic Substances, Pittccon Conference 2021, 2021.03, 長い飛行時間と短い飛行時間のフライトチューブを備えた時間相関単一イオン計数質量分析計を開発し、アレルゲン物質の微量分析を行った。.
22.	今坂 智子, Siddihalu Lakshitha Madunil, Lu Wen, 吉永 勝法, 今坂 藤太郎, フェムト秒レーザーイオン化質量分析法の開発とその応用, 一般社団法人レーザー学会学術講演会第41回年次大会（招待講演）, 2021.01, フェムト秒レーザーをイオン化光源とするガスクロマトグラフ質量分析法の開発やその応用として廃棄物処理場の土壌分析によるダイオキシン類の測定や、香料中のアレルギー物質、化学兵器剤代謝物質、爆発物などの解析を行った。.
23.	Siddihalu Lakshktha Madunil, Totaro Imasaka, Tomoko Imasaka, Laser ionization time-of-flight mass spectrometry of drug-related compounds, 日本分析化学会 第69年会, 2020.09.
24.	Wen Lu, Totaro Imasaka, Tomoko Imasaka, Derivatization of perfluorocarboxylic acids with 2-bromomethylnaphthalene for gas chromatography combined with flame ionization detection/laser ionization mass spectrometry., 日本分析化学会 第69年会, 2020.09.
25.	Siddihalu Lakshitha Madunil, Totaro Imasaka, Tomoko Imasaka, Studies on Ionization Mechanism of 4-Methylcyclohexanol for Observing a Molecular Ion, New Trends in Photophysics of Photochemistry and their Applications-International Symposium between ETH Zürich and Kyushu University-　（招待講演）, 2020.01.
26.	Tomoko Imasaka, Trace Analysis of Organic Substances by Laser Ionization Mass Spectrometry, New Trends in Photophysics of Photochemistry and their Applications-International Symposium between ETH Zürich and Kyushu University-　（基調講演）, 2020.01.
27.	Yuta Nakano, Tomoko Imasaka, Totaro Imasaka, Generation of an Intense Few-femtosecond Optical Pulse in the Near-Infrared and Deep-Ultraviolet Regions, New Trends in Photophysics of Photochemistry and their Applications -International Symposium between ETH Zürich and Kyushu University-　（基調講演）, 2020.01.
28.	Lu Wen, Tomoko Imasaka, Totaro Imasaka, Analysis of Perfluorocarboxylic Acids by Femtosecond Laser Ionization Mass Spectrometry, Frontiers in Chemistry, Biology, and Earth Science-International Symposium between National Taiwan University and Kyushu University-（招待講演）, 2019.12.
29.	Siddihalu Lakshitha Madunil, Totaro Imasaka, Tomoko Imasaka, Ionization Efficiencies of Chlorinated Pesticides at Different Femtosecond Laser Pulse Widths, Challenge in Chemistry-The State of the Art- International Symposium between National University of Singapore and Kyushu University（招待講演）, 2019.11.
30.	Tomoko Imasaka, Femtosecond Ionization Mass Spectrometry for Detection of Novichok: Quantum Chemical Calculation for the Spectral Properties, Challenge in Chemistry-The State of the Art- International Symposium between National University of Singapore and Kyushu University（基調講演）, 2019.11.
31.	Tomoko Imasaka, Totaro Imasaka, Laser Ionization Mass Spectrometry -Basic Principles and Applications-, the 16th Annual Conference of the Taiwan Society for Mass Spectrometry（基調講演）, 2019.07.
32.	Tomoko Imasaka, Siddihalu Lakshitha Madunil, Totaro Imasaka, Spectroscopic Properties of “Novichok” Theoretically Calculated for Gas Chromatography/Femtosecond Ionization Mass Spectrometry, the 16th Annual Conference of the Taiwan Society for Mass Spectrometry（招待講演）, 2019.07.
33.	Tomoko Imasaka, Totaro Imasaka, Femtosecond Ionization Mass Spectrometry for Application to Forensic Science, The 2019 National Taiwan Normal University (NTNU)-Kyushu Univeristy Joint Forum on Facilitating Interdisciplinary Research and Education（招待講演）, 2019.05.
34.	Tomoko Imasaka, Siddihalu Lakshitha Madunil, Totaro Imasaka, Study on Photoionization Process in Mass Spectrometry Based on Quantum Chemical Calculation, The 2019 National Taiwan Normal University (NTNU)-Kyushu Univeristy Joint Forum on Facilitating Interdisciplinary Research and Education（招待講演）, 2019.05.
35.	Siddihalu Lakshktha Madunil, Tomoko Imasaka, Totaro Imasaka, Gas chromatography/mass spectrometry of highly-toxic organochlorine pesticides using an ultraviolet femtosecond laser as an ionization source, 日本分析化学会 第79回分析化学討論会, 2019.05.
36.	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, PQE-2019, the 49th Winter Colloquium on the Physics of Quantum Electronics（招待講演）, 2019.01.
37.	Tomoko Imasaka, Totaro Imasaka, How can we detect "Novichok"?, PQE-2019, The 49th Winter Colloquium on the Physics of Quantum Electronics., 2019.01.
38.	Siddihalu Lakshitha Madunil, Tomoko Imasaka, Totaro Imasaka, An Ultrashort Ultraviolet Optical Pulse for Ionization of Pesticides in Multiphoton Ionization Mass Spectrometry, PQE-2019, the 49th Winter Colloquium on the Physics of Quantum Electronics, 2019.01.
39.	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（招待講演）, 2018.10.
40.	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（招待講演）, 2018.10.
41.	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（招待講演）, 2018.10.
42.	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（招待講演）, 2018.10.
43.	Yuanyuan Tang, Adan Li, Tomoko Imasaka, Totaro Imasaka, Femtosecond ionization mass spectrometry for trace analysis of environmental pollutants adsorbed on particulate matter 2.5, The 14th Asian Conference on Analytical Sciences (ASIANALYSIS XIV)（招待講演）, 2018.04.
44.	Tiantian Ju, Katsunori Yoshinaga, Hiroshi Nakamura, Adan Li, Tomoko Imasaka, Totaro Imasaka, Photoionization mass spectrometry based on time-correlated single ion counting using a femtosecond laser, The 14th Asian Conference on Analytical Sciences (ASIANALYSIS XIV), 2018.04.
45.	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 (ASIANALYSIS XIV) , 2018.04.
46.	Xixiang Yang, Tomoko Imasaka, Totaro Imasaka, Multi-residue determination of pesticides by femtosecond lasers ionization mass spectrometry, The 14th Asian Conference on Analytical Sciences (ASIANALYSIS XIV), 2018.04.
47.	A. Li, T. P. Dinh, 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.
48.	Tiantian Ju, Katsunori Yoshinaga, Hiroshi Nakamura, Adan Li, Tomoko Imasaka, Totaro 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.
49.	T. Imasaka, X. Yang, A. Li, T. Imasaka, Theoretical calculation of the elution order of (+/-)-α-hexachlorocyclohexane separated by a stationary phase consisting of permethylated γ-cyclodextrin in gas chromatography, Euroanalysis2017, 2017.08.
50.	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.
51.	T. Fujii, T. Imasaka, T. Imasaka, An ultraviolet femtosecond laser for multiphoton ionization in mass spectrometry, Joint 13th Asia Pacific Physics Conference and 22nd Australian Institute of Physics Congress（キーノート講演）, 2016.12.
52.	A. Hamachi, T. Imasaka, T. 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)（基調講演）, 2016.12.
53.	A. Hamachi, H. Kouno, T. Imasaka, T. Imasaka, Efficient nonresonant multiphoton ionization in the femtosecond region, Joint 13th Asia Pacific Physics Conference and 22nd Australian Institute of Physics Congress, 2016.12.
54.	藤井 卓也, 今坂 智子, 今坂 藤太郎, 多光子イオン化質量分析法を用いるニトロ多環芳香族炭化水素の還元計測, 日本分析化学会第65年会, 2016.09.
55.	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（依頼講演）, 2016.06.
56.	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.
57.	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.
58.	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)（招待講演）, 2016.01.
59.	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.
60.	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.
61.	伊東山 登, 松井 大宜, 山本 重一, 今坂 智子, 今坂 藤太郎, ガスクロマトグラフィー/多光子イオン化/質量分析法を用いたPM2.5に含まれる多環芳香族炭化水素化合物類の分析, 日本分析化学会第64年会, 2015.09, 近年、大気汚染物質としてPM2.5が注視される。これに含まれる無置換多環芳香族炭化水素 (PPAHs)、ニトロ多環芳香族炭化水素(NPAHs) の一部は発がん性を持つことが知られている。本研究ではガスクロマトグラフィー/多光子イオン化/飛行時間型質量分析法(GC/MPI/ToF-MS)を用いたPM2.5中PAHsとNPAHsの分析について検討した。.
62.	T. Imasaka, A. Hamachi, T. Okuno, T. 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), 2015.05.
63.	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.
64.	今坂智子, 濱地彬文, 奥野智也, 今坂藤太郎, 多光子イオン化質量分析における深紫外フェムト秒光パルス幅のオンサイト簡易測定, 第62回応用物理学会春季学術講演会, 2015.03.
65.	T. Imasaka, T. Imasaka, Spectral properties evaluated using quantum chemical calculation for the measurement of the explosives, the 30th International Symposium on Chromatography, ISC 2014, 2014.09.
66.	今坂 智子, 今坂 藤太郎, 量子化学計算による神経ガスの分光学的性質の予測, 第74回分析化学討論会, 2014.05.
67.	今坂 智子, 今坂 藤太郎, 爆発物のレーザーイオン化波長に関する理論的研究, 日本分析化学会第62年会, 2013.09, レーザーイオン化質量分析法は、特定の物質を選択的に測定する場合に極めて有効である。最近、テロなどで種々の爆発物が利用されているが、それらを効率よくイオン化する波長は求められていない。そこで、本研究では量子化学計算により、励起及びイオン化エネルギーを求め、これらを分析するための条件を明らかにした。.
68.	T. Okuno, T. Imasaka, Y. Kida, T. 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 (ASIANALYSIS XII), 2013.08.
69.	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.
70.	高尾佳也, 今坂智子, 今坂藤太郎, 第三高調波発生を用いたパルス幅の計測 - ２オクターブに及ぶ周波数帯域の利用 -, 2012年 秋季 第73回応用物理学会学術講演会, 2012.09.
71.	今坂智子, 奥野智也, 今坂藤太郎, 超短パルス光のパルス幅測定の研究‐広いスペクトル領域で２＋１イオン化する分子の探索‐, 日本分析化学会第61年会, 2012.09.
72.	Tomoko Imasaka, Totaro Imasaka, Molecules with a One Octave Frequency Domain for the Measurement of the 1-fs Optical Pulse Width , the Conference on Lasers and Electro-Optics 2012(CLEO:2012), JTh2A.15, 2012.05.
73.	T. Imasaka, T. Imasaka, Molecules with a One Octave Frequency Domain for the Measurement of the 1-fs Optical Pulse Width, 2012 Conference on Lasers and Electro-Optics (CLEO), 2012.05.
74.	今坂智子, 今坂藤太郎, 極限超短パルス光のパルス幅測定の研究‐広いスペクトル領域で2光子イオン化する分子の探索‐, 日本分析化学会第60年会, 2011.09.
75.	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.
76.	今坂智子, LI Adan, 今坂藤太郎, ガスクロマトグラフ/レーザー多光子イオン化/飛行時間型質量分析計を用いる農薬分析のための量子化学計算, 日本化学会講演予稿集, 2011.03.
77.	今坂智子, 下道治, 内村智博, 今坂藤太郎, 爆発物”トリアセトントリペルオキシド”のガスクロマトグラフ／質量分析における複数ピークの帰属に関する理論的考察, 日本分析化学会第59年会, 2010.09.
78.	下道治, 今坂智子, 渡邉優香, 内村智博, 今坂藤太郎, レーザーイオン化法による多臭素化ジフェニルエーテルのガスクロマトグラフィー‐質量分析, 日本化学会講演予稿集, 2010.03.
79.	Osamu Shitamichii, Tomoko Imasaka, Yuka Watanabe-Ezoe, Tomohiro Uchimura, and Totaro Imasaka, Ultraviolet laser ionization of polybrominated diphenyl ethers in mass spectrometry, The International Symposium on Environmental Problems in East Asia 2009, 2009.12.
80.	今坂智子, 塚谷裕子, 清水隆史, 財津慎一, 内村智博, 今坂藤太郎, テロに利用される爆発物"トリアセトントリペルオキシド“の物性の理論予測, 日本分析化学会第58年会, 2009.09.
81.	S. Yamaguchi, T. Uchimura, T. Imasaka, T. Imasaka, Trace Analysis of Triacetone Triperoxide (TATP) by Means of Gas Chromatography Combined with Femtosecond Laser Ionization/Time-of-Flight Mass Spectrometry, 10th Asian Conference on Analytical Sciences (Asianalysis X), 2009.08.
82.	Tomoko Imasaka, Nami Nakamura, Yuji Sakoda, Satoshi Yamaguchi, Yuka Watanabe-Ezoe, Tomohiro Uchimura, Totaro Imasaka, Data Processing Technique in Gas Chromatography/ Multiphoton Ionization/Time-of-Flight Mass Spectrometry, International Symposium on Environmental Analysis 2008, 2008.11.
83.	中村奈未, 渡辺優香, 内村智博, 今坂智子, 今坂藤太郎, ダイオキシン分析におけるレーザーイオン化質量分析法の信頼性評価及び土壌試料の測定, 日本分析化学会第５７年会, 2008.09.
84.	Y. Watanabe-Ezoe, N. Nakamura, Y. Sakoda, S. Yamaguchi, T. Imasaka, T. Uchimura, T. Imasaka, Gas Chromatography/Multiphoton Ionization/Mass Spectrometry of Pentachloro Dibenzofurans in Soil, DIOXIN 2008 (28th International Symposium on halogenated persistent Organic Pollutants (POPs), 2008.08.
85.	今坂智子, 山口智志, 内村智博, 今坂藤太郎, ガスクロマトグラフィー/多光子イオン化/飛行時間型質量スペクトル（GC/MPI/TOF-MS）分析におけるデータ解析, 日本化学会第88春季年会, 2008.03.
86.	S. Yamaguchi, T. Itoh, Y. Watanabe-Ezoe, T. Uchimura, T. Imasaka, T. Imasaka, Multiphoton Ionization/Mass Spectrometry for Trace Analysis of Dioxin, IUPAC 2007 (44th International Union of Pure and Applied Chemistry General Assembly), 2007.08.
87.	S. Hirokawa, T. Imasaka, Y. Oyakawa, M. Oishi, T. Imasaka, Electron Correlation Correction Method to Precisely Compute the (0-0) S1←S0 Transition Energies: Polychlorinated Biphenyls (PCBs), The 8th Asian conference on Analytical Sciences Abstracts, 2005.10.
88.	廣川昭二, 今坂智子, 今坂藤太郎, 多塩素化ジベンゾフランの塩素置換パターン、分子特性、及び毒性に関する理論的研究, 日本化学会第84春季年会, 2004.03.
89.	今坂智子, 廣川昭二, 多塩素化ジベンゾフラン(PCDFs)のS0状態とS1状態の構造とS1←S0電子遷移のAb initio MO計算, 日本化学会第83春季年会, 2003.03.
90.	今坂智子, 廣川昭二, β-ヒドロキノン包接結晶におけるゲスト系の配向相転移に及ぼすホスト系の影響に関する理論的研究, 日本化学会第79春季年会, 2001.03.
91.	今坂智子, 廣川昭二, SO2-及びD2S-β-ヒドロキノン包接結晶の配向相転移に及ぼす結晶場と空孔被占率の効果に関する理論的研究, 日本化学会第78春季年会, 2000.03.
92.	今坂智子, 廣川昭二, β-ヒドロキノン包接結晶の空孔被占率と相転移, 日本化学会第76春季年会, 1999.03.
93.	今坂智子, 廣川昭二, SO2-およびD2S-β-キノール包接化合物におけるゲスト-ゲスト相互作用と相転移, 第32回化学関連支部合同九州大会（共催：日本化学会九州支部他）, 1995.07.
94.	Shoji Hirokawa, Tomoko Imasaka and Takasuke Matsuo, Orientational Orgering of Guest Molecules in the β-Quinol Clathrates of H2S and D2S, WATOC’93 (The Third World Congress of Theoretical Organic Chemists), 1993.07.

1.	Tomoko Imasaka, アメリカ化学会の国際誌 Analytical Chemistry (Top10%ジャーナル）, Vol.94, Number 42, Oct. 2022の表紙, 2022.10.
2.	Tomoko Imasaka, アメリカ質量分析学会の国際誌 Journal of the American Society for Mass Spectroscopy、Vol.33, Issue 1, Jan. 2022の表紙, 2022.01.

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