Publications

Original Papers

An absorption spectrophotometer compatible paper-based thin-layer cuvette with an integrated pneumatic pump

Kotaro Morita, Honomi Koiso, Reina Kudo and Naoki Hirayama
Analytical Methods, 2021, 13,  4858-4863
doi:10.1039/D1AY01138C
(Selected as Front Cover Illustration)

Reviews

Recent progress in ionic liquid extraction for the separation of rare earth elements

Hiroyuki Okamura and Naoki Hirayama
Analytical Sciences, 2021, 37, 119-130
doi:10.2116/analsci.20SAR11

Original Papers

Mutual separation of Fe(II) and Fe(III) using cyclohexane/water/ionic-liquid triphasic extraction system with 2,2'-bipyridine and tri-n-octylphosphine oxide

Mizuki Toita, Kotaro Morita and Naoki Hirayama
Analytical Sciences, 2020, 36, 1387-1391
doi:10.2116/analsci.20P198
(Selected as Cover Illustration)

Capillary electrophoretic characterization of water-soluble carbon nanodots formed from glutamic acid and boric acid under microwave irradiation

Toshio Takayanagi, Sota Iwasaki, Yuta Becchaku, Shun Yabe, Kotaro Morita, Hitoshi Mizuguchi and Naoki Hirayama
Analytical Sciences, 2020, 36, 941-946
doi:10.2116/analsci.19P484

Capillary electrophoretic characterization of carbon nanodots prepared from glutamic acid in an electric furnace

Toshio Takayanagi, Sota Iwasaki, Kotaro Morita, Naoki Hirayama and Hitoshi Mizuguchi
Chromatography, 2020, 41, 103-107
doi:10.15583/jpchrom.2020.010

Synergistic ion-pair extraction and separation of trivalent lanthanoid ions with 4-isopropyltropolone and 1,10-phenanthroline into o-dichlorobenzene

Takuya Yamashita, Yoshio Nishiyama, Kotaro Morita, Hirohisa Nagatani and Hisanori Imura
Analytical Sciences, 2020, 36, 479-484
doi:10.2116/analsci.19P394
(Selected as Cover Illustration)

Synergistic enhancement of the extraction and separation efficiencies of lanthanoid(III) ions by the formation of charged adducts in an ionic liquid

Hiroyuki Okamura, Masayoshi Mizuno, Naoki Hirayama, Kojiro Shimojo, Hirochika Naganawa and Hisanori Imura
Industrial & Engineering Chemistry Research, 2020, 59, 329-340
doi:10.1021/acs.iecr.9b04998

Reviews

錯生成と液相間物質移動に基づく金属イオン分離系の構築と機能評価に関する研究

平山直紀
日本イオン交換学会誌, 2020, 31, 29-36
doi:10.5182/jaie.31.29

Original Papers

Ionic liquid chelate extraction behavior of trivalent Group 13 metals into 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imides using 8-quinolinol as chelating extractant

Ayano Eguchi, Kotaro Morita and Naoki Hirayama
Analytical Sciences, 2019, 35, 1003-1007
doi:10.2116/analsci.19P132
(Selected as Hot Articles)

Reviews

デンドリマー型イオン液体を用いた金属イオンの抽出

戸井田美月
ぶんせき, 2019, 353-354

Original Papers

Formation of minimal third phase in ionic liquid extraction system with trioctylphosphine oxide and its possible application to extraction concentration

Mizuki Toita, Kotaro Morita and Naoki Hirayama
Analytical Sciences, 2018, 34, 1063-1065
doi:10.2116/analsci.18C016
(Selected as Hot Articles)

Extraction ability of 4-benzoyl-3-phenyl-5-isoxazolone towards 4f-ions into ionic and molecular media

Maria Atanassova, Hiroyuki Okamura, Ayano Eguchi, Yuki Ueda, Tsuyoshi Sugita and Kojiro Shimojo
Analytical Sciences, 2018, 34, 973-978
doi:10.2116/analsci.18P166

Reviews

イオン液体から成る二相系における構成イオンの役割

江口綾乃
ぶんせき, 2018, 33

Original Papers

Effect of the elemental composition of precursors from amino acids and their binary mixtures on the photoluminescent intensity of carbon nanodots

Kotaro Morita, Shusei Kurusu, Haruka Kodama and Naoki Hirayama
Analytical Sciences, 2017, 33, 1461-1464
doi:10.2116/analsci.33.1461
(Selected as Cover Illustration and Hot Articles)

Distribution equilibria of amphoteric 8-quinolinol between 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and aqueous phases and their effect on ionic liquid chelate extraction behavior of iron(III)

Ayano Eguchi, Kotaro Morita and Naoki Hirayama
Analytical Sciences, 2017, 33, 1447-1451
doi:10.2116/analsci.33.1447

Electrocatalytic reduction of free chlorine at an N,N-diethylaniline-grafted carbon electrode for improved sensitivity in amperometric detection

Kotaro Morita and Naoki Hirayama
Analytical Sciences, 2017, 33, 5-7
doi:10.2116/analsci.33.5

Proceedings

Anomalously suppressed ion-exchange extraction behavior of Ni(II) into ionic liquids with using N,N,N’,N’-tetrakis(2-pyridylmethyl)ethylenediamine as a neutral chelator

Natsumi Asano, Kotaro Morita and Naoki Hirayama
Proceedings of ISEC2017, 2017, 142-145
Link to Proceedings Web Site

   Reviews

金属イオン分離材としてのイオン液体の機能解析

平山直紀
日本イオン交換学会誌, 2017, 28, 37-44
doi:10.5182/jaie.28.37

Original Papers

Synergistic ion-pair extraction of strontium ion with tri-n-octylphosphine oxide and dicyclohexano-18-crown-6

Mami Onizaki, Kotaro Morita and Naoki Hirayama
Analytical Sciences, 2016, 32, 1367-1370
doi:10.2116/analsci.32.1367

Extraction behavior of divalent metal cations with 2-mercaptopyridine N-oxide in ionic liquid chelate extraction

Sumiyuki Kimura, Yoshio Shimizu, Ayano Eguchi and Naoki Hirayama
Solvent Extraction Research and Development, Japan, 2016, 23, 145-150
doi:10.15261/serdj.23.145

Potential-dependent adsorption and orientation of meso-substituted porphyrins at liquid|liquid interfaces studied by polarization-modulation total internal reflection fluorescence spectroscopy

Sho Yamamoto, Hirohisa Nagatani, Kotaro Morita and Hisanori Imura
The Journal of Physical Chemistry C, 2016, 120, 7248-7255
doi:10.1021/acs.jpcc.6b02178

非イオン界面活性剤水溶液の相分離に及ぼす多価フェノールの効果とアンチモン(V)の曇り点抽出への応用

池端浩紀，平山直紀，井村久則
分析化学, 2016, 65, 65-70
doi:10.2116/bunsekikagaku.65.65

   Original Papers

Photoluminescent detection of nitrite with carbon nanodots prepared by microwave-assisted synthesis

Kotaro Morita, Akane Kobayashi, Hirohisa Nagatani and Hisanori Imura
Analytical Sciences, 2015, 31, 481-485
doi:10.2116/analsci.31.481
(Selected as Hot Articles)

   Books

基礎分析化学

平山直紀　他 (小熊幸一，酒井忠雄　編著)
朝倉書店, 2015
ISBN 978-4-254-14102-3
担当分: 15-28, 36-42, 43-51
出版社サイトはこちら

Original Papers

A specific synergistic effect in ionic liquid chelate extraction based on neutral ternary chloro-complex formation

Motoya Sakato and Naoki Hirayama
Analytical Sciences, 2014, 30, 783-785
doi:10.2116/analsci.30.783
(Selected as Cover Illustration)

Salting-out phase separation system of water–tetrahydrofuran with co-using 1-butyl-3-methylimidazolium chloride and sodium chloride for possible extraction separation of chloro-complexes

Naoki Hirayama, Takaaki Higo and Hisanori Imura
Solvent Extraction Research and Development, Japan, 2014, 21, 71-76
doi:10.15261/serdj.21.71

Reviews

イオン液体を抽出相とする金属イオンの溶媒抽出

平山直紀
ぶんせき, 2014, 177-182

Original Papers

Valence discriminative detection of metal cations by a chromotropic acid-grafted glassy carbon electrode

Kotaro Morita, Kenichi Shibata, Hirohisa Nagatani, Naoki Hirayama and Hisanori Imura
Analytical Sciences, 2013, 29, 95-99
doi:10.2116/analsci.29.95

Books

これからの環境分析化学入門

平山直紀　他　(小熊幸一　他　編著)
講談社, 2013
ISBN 978-4-06-154382-9
担当分: 134-157　(平山直紀，千賀有希子　共著)
出版社サイトはこちら

ベーシックマスター 分析化学

平山直紀　他　(蟻川芳子，小熊幸一，角田欣一　共編)
オーム社, 2013
ISBN 978-4-274-21425-7
担当分: 121-138
出版社サイトはこちら

Original Papers

Specific cooperative effect of a macrocyclic receptor for metal ion transfer into an ionic liquid

Hiroyuki Okamura, Atsushi Ikeda-Ohno, Takumi Saito, Noboru Aoyagi, Hirochika Naganawa, Naoki Hirayama, Shigeo Umetani, Hisanori Imura and Kojiro Shimojo
Analytical Chemistry, 2012, 84, 9332-9339
doi:10.1021/ac302015h

5-アルキルオキシメチル-8-キノリノール誘導体の銅(II)イオン抽出能に及ぼす7位ハロゲン化の効果

松田駿太朗，森田耕太郎，平山直紀，井村久則
分析化学, 2012, 61, 699-704
doi:10.2116/bunsekikagaku.61.699

Evaluation of a hydrophilic ionic liquid as a salting-out phase separation agent to a water–tetrahydrofuran homogeneous system for aqueous biphasic extraction separation

Naoki Hirayama, Takaaki Higo and Hisanori Imura
Analytical Sciences, 2012, 28, 541-543
doi:10.2116/analsci.28.541

Laser-induced fluorescence and infrared spectroscopic studies on the specific solvation of tris(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)europium(III) in an ionic liquid

Hiroyuki Okamura, Hiroki Sakae, Keiji Kidani, Naoki Hirayama, Noboru Aoyagi, Takumi Saito, Kojiro Shimojo, Hirochika Naganawa and Hisanori Imura
Polyhedron, 2012, 31, 748-753
doi:10.1016/j.poly.2011.10.031

Reviews

溶媒抽出にイオン液体を使う

平山直紀
化学と教育, 2012, 60, 64-65
doi:10.20665/kakyoshi.60.2_64

Original Papers

Grafting of phenylboronic acid on a glassy carbon electrode and its application as a reagentless glucose sensor

Kotaro Morita, Naoki Hirayama, Hisanori Imura, Akira Yamaguchi and Norio Teramae
Journal of Electroanalytical Chemistry, 2011, 656, 192-197
doi:10.1016/j.jelechem.2010.11.023

Effect of organic cations and solvents on the ion-pair extraction of boric acid with salicyl alcohol

Keisuke Morita, Naoki Hirayama, Kotaro Morita and Hisanori Imura
Solvent Extraction Research and Development, Japan, 2011, 18, 199-203
doi:10.15261/serdj.18.199

Reviews

金属イオン抽出媒体としてのイオン液体

平山直紀
日本イオン交換学会誌, 2011, 22, 73-80
doi:10.5182/jaie.22.73

Chelate extraction of metals into ionic liquids

Naoki Hirayama
Solvent Extraction Research and Development, Japan, 2011, 18, 1-14
doi:10.15261/serdj.18.1
(Selected as Cover Picture)

「イオン液体」という物質群 ―歴史と定義―

平山直紀
日本イオン交換学会誌, 2011, 22, 33-38
doi:10.5182/jaie.22.33

  Books

改訂６版　分析化学便覧

平山直紀　他　(日本分析化学会　編)
丸善出版, 2011
ISBN 978-4-621-08409-0
担当分: 672-674
出版社サイトはこちら

分析化学実技シリーズ　機器分析編・１　吸光・蛍光分析

井村久則，菊地和也，平山直紀，森田耕太郎，渡會　仁　(日本分析化学会　編)
共立出版, 2011
ISBN 978-4-320-04389-3
担当分: 9-13, 71-112, 139-158
出版社サイトはこちら

Original Papers

An 8-sulfonamidoquinoline derivative with imidazolium unit as an extraction reagent for use in ionic liquid chelate extraction systems

Keisuke Morita, Naoki Hirayama, Kotaro Morita and Hisanori Imura
Analytica Chimica Acta, 2010, 680, 21-25
doi:10.1016/j.aca.2010.09.031

Extraction of Cu(II) with dioctyldithiocarbamate and kinetic study of the extraction using a two-phase microflow system

Kotaro Morita, Takuo Hagiwara, Naoki Hirayama and Hisanori Imura
Solvent Extraction Research and Development, Japan, 2010, 17, 209-214
doi:10.15261/serdj.17.209
(Selected as Cover Picture)

Synergistic effect of 18-crown-6 derivatives on chelate extraction of lanthanoids(III) into an ionic liquid with 2-thenoyltrifluoroacetone

Hiroyuki Okamura, Naoki Hirayama, Kotaro Morita, Kojiro Shimojo, Hirochika Naganawa and Hisanori Imura
Analytical Sciences, 2010, 26, 607-611
doi:10.2116/analsci.26.607