KINDAI UNIVERSITY


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NAKAGUCHI Yuzuru

Profile

FacultyDepartment of Science / Graduate School of Science and Engineering Research / Research Institute for Science and Technology
PositionProfessor
Degree
Commentator Guidehttps://www.kindai.ac.jp/meikan/331-nakaguchi-yuzuru.html
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Last Updated :2020/09/02

Education and Career

Education

  •  - 1986 , Kinki University, Graduate School, Division of Chemistry
  •   1978 04  - 1982 03 , Kinki University, School of Science and Engineering
  •   1982 04  - 1984 03 , Kinki University, Graduate School of Chemistry
  •   1984 04  - 1986 03 , Kinki University, Graduate School of Chemistry

Academic & Professional Experience

  •   2011 04 ,  - 現在, Professor, School of Science and Engineering, Kindai University
  •   2007 04 ,  - 2011 03 , Associate Professor, School of Science and Engineering, Kindai University
  •   2002 04 ,  - 2007 03 , Assistant professor, School of Science and Engineering, Kindai University
  •   1996 04 ,  - 2002 03 , Lecturer, School of Science and Engineering, Kindai University
  •   1986 04 ,  - 1996 03 , Accistant, School of Science and Engineering, Kindai University

Research Activities

Research Areas

  • Natural sciences, Space and planetary science

Research Interests

  • Ocean chemistry, Geochemistry

Published Papers

  • Diural distributions of ionic constituent in the aerosol over the Higashi-osaka in 2014, NAKAGUCHI Yuzuru, TAKAYAMA Shintaro, SANO Itaru, Science and Technology, Science and Technology, 29, 33 - 41, 2017
  • tudies on the chemical composition of suspended particulate matter in the Indian and the Antarctic Ocean, NAKAGUCHI Yuzuru, HIROTA Akiko, Science and Technology, Science and Technology, 28, 1 - 11, 2016
  • Effect of basification on trace metal speciation in the Amano River, NAKAGUCHI Yuzuru, IKEDA Yoshinori, HAMAYA Shin, ASAKURA Tomoya, 50, 227 - 241, 2016 , Refereed
  • The origin analysis of Asian-dust particles collected at Higashiosaka Japan in 2012, NAKAGUCHI Yuzuru, FUJIWARA Tukasa, MAEDA Koouhei, TAKEDA Koichi, SANO Itaru, Science and Technology, Science and Technology, 27, 65 - 70, 2015
  • An individual particle analysis of Asian-dust particles collected at Higashiosaka Japan in 2010, NAKAGUCHI Yuzuru, FUJIWARA Tukasa, TAKEDA Koichi, SANO Itaru, Science and Technology, Science and Technology, 26, 41 - 49, 2014
  • Geochemical studies on the dissolved rare earth elements in the Yodo River system, NAKAGUCHI Yuzuru, KABUKI Jyunya, MASUDA Harue, NAKAJO Takeshi, Science and Technology, Science and Technology, 25, 37 - 48, 2013
  • Selenium speciation in the Todo River system, NAKAGUCHI Yuzuru, FUYUNO Masashi, YAMANAKA Kouhei, MASUDA Harue, NAKAJO Takeshi, Science and Technology, Science and Technology, 23, 59 - 65, 2011
  • Studies on Bioactive Trace Metals in the Western Tropical Pacific Ocean(2)-, NAKAGUCHI Yuzuru, FUJITA Akinori, NAKAGAWA Yoko, SHITASHIMA Kiminori, Bull. Soc. Sea Water Sci., Jpn., Bull. Soc. Sea Water Sci., Jpn., 64(4), 217 - 224, 2010 , Refereed
  • Selenium speciation in the Eastern Tropical and Subtropical South Pcific Ocean, 21, 25 - 33, Feb. 2009
  • Selenium Speciation in the Western North Pacific Ocean, Bull. Soc. Sea Water Sci. Jpn., Bull. Soc. Sea Water Sci. Jpn., 63(1), 39 - 48, Feb. 2009
  • The accumulation rate and benthic fluxes for selenium in the marginal seas, 19, 23 - 29, Feb. 2007
  • Distribution of stable isotopes of particulate lead in the atmosphere in Osaka, Japan, Science and technology, Science and technology, 18, 35 - 40, Feb. 2006
  • The Distribution of Dissolved Selenium Species in the Subtropical North Pacific Ocean The Relation with North Pacific Intermediate Water, (37), 15 - 22, Sep. 2001
  • Analytical Studies of Standard Solutoin for Nutrients in the Ocean, (37), 37 - 40, Sep. 2001
  • Early Diagenetic Behavior of Selenium in the Northwestern Pacific Ocean Sediment, (37), 23 - 29, Sep. 2001
  • The seasonal variation of biological activity and dissolved organic carbon in the norther North Pacific, (37), 31 - 55, Sep. 2001
  • The Determination of Selenium Species in Sea Water by DAN HPLC Method, 55(5), 333 - 339, 2001
  • The GEOTRACES Intermediate Data Product 2017, Reiner Schlitzer, Robert F. Anderson, Elena Masferrer Dodas, Maeve Lohan, Walter Geibert, Alessandro Tagliabue, Andrew Bowie, Catherine Jeandel, Maria T. Maldonado, William M. Landing, Donna Cockwell, Cyril Abadie, Wafa Abouchami, Eric P. Achterberg, Alison Agather, Ana Aguliar-Islas, Hendrik M. van Aken, Morten Andersen, Corey Archer, Maureen Auro, Hein J. de Baar, Oliver Baars, Alex R. Baker, Karel Bakker, Chandranath Basak, Mark Baskaran, Nicholas R. Bates, Dorothea Bauch, Pieter van Beek, Melanie K. Behrens, Erin Black, Katrin Bluhm, Laurent Bopp, Heather Bouman, Katlin Bowman, Johann Bown, Philip Boyd, Marie Boye, Edward A. Boyle, Pierre Branellec, Luke Bridgestock, Guillaume Brissebrat, Thomas Browning, Kenneth W. Bruland, Hans-Jürgen Brumsack, Mark Brzezinski, Clifton S. Buck, Kristen N. Buck, Ken Buesseler, Abby Bull, Edward Butler, Pinghe Cai, Patricia Cámara Mor, Damien Cardinal, Craig Carlson, Gonzalo Carrasco, Núria Casacuberta, Karen L. Casciotti, Maxi Castrillejo, Elena Chamizo, Rosie Chance, Matthew A. Charette, Joaquin E. Chaves, Hai Cheng, Fanny Chever, Marcus Christl, Thomas M. Church, Ivia Closset, Albert Colman, Tim M. Conway, Daniel Cossa, Peter Croot, Jay T. Cullen, Gregory A. Cutter, Chris Daniels, Frank Dehairs, Feifei Deng, Huong Thi Dieu, Brian Duggan, Gabriel Dulaquais, Cynthia Dumousseaud, Yolanda Echegoyen-Sanz, R. Lawrence Edwards, Michael Ellwood, Eberhard Fahrbach, Jessica N. Fitzsimmons, A. Russell Flegal, Martin Q. Fleisher, Tina van de Flierdt, Martin Frank, Jana Friedrich, Francois Fripiat, Henning Fröllje, Stephen J.G. Galer, Toshitaka Gamo, Raja S. Ganeshram, Jordi Garcia-Orellana, Ester Garcia-Solsona, Melanie Gault-Ringold, Ejin George, Loes J.A. Gerringa, Melissa Gilbert, Jose M. Godoy, Steven L. Goldstein, Santiago R. Gonzalez, Karen Grissom, Chad Hammerschmidt, Alison Hartman, Christel S. Hassler, Ed C. Hathorne, Mariko Hatta, Nicholas Hawco, Christopher T. Hayes, Lars-Eric Heimbürger, Josh Helgoe, Maija Heller, Gideon M. Henderson, Paul B. Henderson, Steven van Heuven, Peng Ho, Tristan J. Horner, Yu-Te Hsieh, Kuo-Fang Huang, Matthew P. Humphreys, Kenji Isshiki, Jeremy E. Jacquot, David J. Janssen, William J. Jenkins, Seth John, Elizabeth M. Jones, Janice L. Jones, David C. Kadko, Rick Kayser, Timothy C. Kenna, Roulin Khondoker, Taejin Kim, Lauren Kipp, Jessica K. Klar, Maarten Klunder, Sven Kretschmer, Yuichiro Kumamoto, Patrick Laan, Marie Labatut, Francois Lacan, Phoebe J. Lam, Myriam Lambelet, Carl H. Lamborg, Frédéric A.C. Le Moigne, Emilie Le Roy, Oliver J. Lechtenfeld, Jong-Mi Lee, Pascale Lherminier, Susan Little, Mercedes López-Lora, Yanbin Lu, Pere Masque, Edward Mawji, Charles R. Mcclain, Christopher Measures, Sanjin Mehic, Jan-Lukas Menzel Barraqueta, Pier van der Merwe, Rob Middag, Sebastian Mieruch, Angela Milne, Tomoharu Minami, James W. Moffett, Gwenaelle Moncoiffe, Willard S. Moore, Paul J. Morris, Peter L. Morton, Yuzuru Nakaguchi, Noriko Nakayama, John Niedermiller, Jun Nishioka, Akira Nishiuchi, Abigail Noble, Hajime Obata, Sven Ober, Daniel C. Ohnemus, Jan van Ooijen, Jeanette O'Sullivan, Stephanie Owens, Katharina Pahnke, Maxence Paul, Frank Pavia, Leopoldo D. Pena, Brian Peters, Frederic Planchon, Helene Planquette, Catherine Pradoux, Viena Puigcorbé, Paul Quay, Fabien Queroue, Amandine Radic, S. Rauschenberg, Mark Rehkämper, Robert Rember, Tomas Remenyi, Joseph A. Resing, Joerg Rickli, Sylvain Rigaud, Micha J.A. Rijkenberg, Stephen Rintoul, Laura F. Robinson, Montserrat Roca-Martí, Valenti Rodellas, Tobias Roeske, John M. Rolison, Mark Rosenberg, Saeed Roshan, Michiel M. Rutgers van der Loeff, Evgenia Ryabenko, Mak A. Saito, Lesley A. Salt, Virginie Sanial, Geraldine Sarthou, Christina Schallenberg, Ursula Schauer, Howie Scher, Christian Schlosser, Bernhard Schnetger, Peter Scott, Peter N. Sedwick, Igor Semiletov, Rachel Shelley, Robert M. Sherrell, Alan M. Shiller, Daniel M. Sigman, Sunil Kumar Singh, Hans A. Slagter, Emma Slater, William M. Smethie, Helen Snaith, Yoshiki Sohrin, Bettina Sohst, Jeroen E. Sonke, Sabrina Speich, Reiner Steinfeldt, Gillian Stewart, Torben Stichel, Claudine H. Stirling, Johnny Stutsman, Gretchen J. Swarr, James H. Swift, Alexander Thomas, Kay Thorne, Claire P. Till, Ralph Till, Ashley T. Townsend, Emily Townsend, Robyn Tuerena, Benjamin S. Twining, Derek Vance, Sue Velazquez, Celia Venchiarutti, Maria Villa-Alfageme, Sebastian M. Vivancos, Antje H.L. Voelker, Bronwyn Wake, Mark J. Warner, Ros Watson, Evaline van Weerlee, M. Alexandra Weigand, Yishai Weinstein, Dominik Weiss, Andreas Wisotzki, E. Malcolm S. Woodward, Jingfeng Wu, Yingzhe Wu, Kathrin Wuttig, Neil Wyatt, Yang Xiang, Ruifang C. Xie, Zichen Xue, Hisayuki Yoshikawa, Jing Zhang, Pu Zhang, Ye Zhao, Linjie Zheng, Xin-Yuan Zheng, Moritz Zieringer, Louise A. Zimmer, Patrizia Ziveri, Patricia Zunino, Cheryl Zurbrick, Chemical Geology, Chemical Geology, 493(20), 210 - 223, 2018
    Summary:The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at crossover stations. The IDP2017 consists of two parts: (1) a compilation of digital data for more than 450 TEIs as well as standard hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing an on-line atlas that includes more than 590 section plots and 130 animated 3D scenes. The digital data are provided in several formats, including ASCII, Excel spreadsheet, netCDF, and Ocean Data View collection. Users can download the full data packages or make their own custom selections with a new on-line data extraction service. In addition to the actual data values, the IDP2017 also contains data quality flags and 1-σ data error values where available. Quality flags and error values are useful for data filtering and for statistical analysis. Metadata about data originators, analytical methods and original publications related to the data are linked in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2017 as section plots and rotating 3D scenes. The basin-wide 3D scenes combine data from many cruises and provide quick overviews of large-scale tracer distributions. These 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of tracer plumes near ocean margins or along ridges. The IDP2017 is the result of a truly international effort involving 326 researchers from 25 countries. This publication provides the critical reference for unpublished data, as well as for studies that make use of a large cross-section of data from the IDP2017. This article is part of a special issue entitled: Conway GEOTRACES - edited by Tim M. Conway, Tristan Horner, Yves Plancherel, and Aridane G. González.
  • An off-line automated preconcentration system with ethylenediaminetriacetate chelating resin for the determination of trace metals in seawater by high-resolution inductively coupled plasma mass spectrometry, Tomoharu Minami, Wataru Konagaya, Linjie Zheng, Shotaro Takano, Masanobu Sasaki, Rena Murata, Yuzuru Nakaguchi, Yoshiki Sohrin, ANALYTICA CHIMICA ACTA, ANALYTICA CHIMICA ACTA, 854, 183 - 190, Jan. 2015
    Summary:A novel automated off-line preconcentration system for trace metals (Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) in seawater was developed by improving a commercially available solid-phase extraction system SPE-100 (Hiranuma Sangyo). The utilized chelating resin was NOBIAS Chelate-PA1 (Hitachi High-Technologies) with ethylenediaminetriacetic acid and iminodiacetic acid functional groups. Parts of the 8-way valve made of alumina and zirconia in the original SPE-100 system were replaced with parts made of polychlorotrifluoroethylene in order to reduce contamination of trace metals. The eluent pass was altered for the back flush elution of trace metals. We optimized the cleaning procedures for the chelating resin column and flow lines of the preconcentration system, and developed a preconcentration procedure, which required less labor and led to a superior performance compared to manual preconcentration (Sohrin et al. [5]). The nine trace metals were simultaneously and quantitatively preconcentrated from similar to 120 g of seawater, eluted with similar to 15 g of 1 M HNO3, and determined by HR-ICP-MS using the calibration curve method. The single-step preconcentration removed more than 99.998% of Na, K, Mg, Ca, and Sr from seawater. The procedural blanks and detection limits were lower than the lowest concentrations in seawater for Mn, Ni, Cu, and Pb, while they were as low as the lowest concentrations in seawater for Al, Fe, Co, Zn, and Cd. The accuracy and precision of this method were confirmed by the analysis of reference seawater samples(CASS-5, NASS-5, GEOTRACESGS, and GD) and seawater samples for vertical distribution in the western North Pacific Ocean. (C) 2014 Elsevier B.V. All rights reserved.
  • Post-drilling changes in fluid discharge pattern, mineral deposition, and fluid chemistry in the Iheya North hydrothermal field, Okinawa Trough, Shinsuke Kawagucci, Junichi Miyazaki, Ryota Nakajima, Tatsuo Nozaki, Yutaro Takaya, Yasuhiro Kato, Takazo Shibuya, Uta Konno, Yuzuru Nakaguchi, Kenta Hatada, Hisako Hirayama, Katsunori Fujikura, Yasuo Furushima, Hiroyuki Yamamoto, Tomo-o Watsuji, Jun-ichiro Ishibashi, Ken Takai, GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, 14(11), 4774 - 4790, Nov. 2013
    Summary:The Integrated Ocean Drilling Program (IODP) Expedition 331 investigated the Iheya North hydrothermal field in the Okinawa Trough. Several post-drilling underwater vehicle investigations were conducted over 2 years to identify post-drilling changes in fluid discharge pattern, mineral deposition, and fluid chemistry. Drilling-induced high-temperature hydrothermal fluid vents were identified at deep holes not only near the naturally occurring NBC hydrothermal fluid vent (Site C0016) but also at the seafloor similar to 450 m distal to the NBC vent (Site C0014), where no hydrothermal fluid discharge was observed prior to drilling. A chimney structure at Hole C0016A grew rapidly at the NBC mound crest, where only small chimneys had been found before drilling. A drilling-induced diffuse hydrothermal flow region spread at Site C0014, and this area was newly colonized by the galatheid crab. From a fluid chemistry perspective, the post-drilling hydrothermal fluids were enriched in Cl relative to seawater, although this fluid chemistry was not observed during the 12 years prior to drilling. The Cl-enriched fluid reservoir underlying the subseafloor impermeable layers, observed by IODP Expedition 331, is likely source for the Cl-enriched fluids discharging from the post-drilling vents. The drilling-induced physical disturbance of subseafloor hydrogeological structures would release such fluids to the seafloor. In turn, the rapid chimney growth at the NBC mound crest may also be attributed to highly turbulent fluid flow with the enlarged artificial vent of Hole C0016A, which can contribute to the retention of the fluid-seawater mixture for a sufficiently long period to precipitate sulfide/sulfate minerals on the seafloor.
  • Atmospheric transport and deposition of anthropogenic substances from the Asia to the East China Sea, Mitsuo Uematsu, Hiroshi Hattori, Tokuhiro Nakamura, Yasushi Narita, Jinyoung Jung, Kiyoshi Matsumoto, Yuzuru Nakaguchi, M. Dileep Kumar, MARINE CHEMISTRY, MARINE CHEMISTRY, 120(1-4), 108 - 115, Jun. 2010
    Summary:Experiments conducted aboard the R/V Hakuho Maru (Cruise KH-02-3) in the autumn of 2002 were designed to study the pathways of atmospheric aerosol transport, selected trace elements and major ions composition of particles and quantify their dry deposition over the East China Sea. We determined the concentrations of trace elements Al, Mn, Pb, Se, and Zn and major ions Na(+), SO(4)(2-) and NO(3)(-) in aerosol particles. Aerosols were continuously collected in fine and coarse size fractions with a cut off at 2.5 mu m. Particle number densities (volumes) were determined in four size ranges between 0.1 and <0.5 mu m. High Al concentrations in the coarse mode fractions suggest continental origin of these aerosols. Weather charts revealed conducive meteorological conditions for northeastward air mass transports from the Asian continent. Back trajectory analysis results corroborated with the meteorological observations. Nss-SO(4)(2-), Mn, Pb, Se and Zn were more abundant in the fine than coarse mode fraction, but NO(3)(-) was associated with the latter. About three-fold higher Mn/Al ratio in fine mode than in coarse aerosols (0.042 vs. 0.015, respectively) and a strong correlation between non-crustal Mn and nss-SO(4)(2-) suggest that fine Mn originates from industrial sources. Similarly, non-crustal Pb and Zn in the fine fraction were again significantly correlated with nss-SO(4)(2-) indicating major contributions from anthropogenic activities. Our results highlight the fact that atmospheric pollutants from Asia, including heavy metals and major ions, are carried to the East China Sea even during non-dusty periods. It is necessary to obtain the atmospheric deposition fluxes, wet and dry, throughout the year both by periodic and continuous atmospheric measurements in order to find the biogeochemical significance of Asian aerosols to the East China Sea and North Pacific Ocean. (C) 2010 Elsevier B.V. All rights reserved.

Conference Activities & Talks

  • Study on the bioactive trace metals in the aerosol over the northern North Pacific and the East China Sea., TUJI Naoki, TANIURA Ryou, OKU Natsumi, NAKAGUCHI Yuzuru, The 65th meeting of Geochemical Society of Japan,   2018 09 13
  • Study on improvement of water quality for Yamada pond., NAKAGUCHI Yuzuru, SHIMAYA Hiroki, HONDA Sou, KOIKE Mami, The meeting of Geochemical society of Japan,   2018 09 11
  • Study on basifying river of Yodogawa river system, NAKAGUCHI Yuzuru, TUJI Naoki, GEHOU Kota,   2017 09 28
  • Distributions and atmospheric imput of bioactive trace metals in the East China Sea, NAKAGUCHI Yuzuru, IKEDA Yoshiniri, Oku Natsumi, TANIURA Ryo, TSUJISAKA Makoto, LINJIE Zheng, MINAMI Tomoharu, SOHRIN Yoshiki, Goldshumidt 2017,   2017 08 13
  • Study on basification of the Amano River, NAKAGUCHI Yuzuru, IKEDA Yoshinori, HAMAYA Shin, ASAKURA Tomoya, The 63th meeting of the Geochemical Society of Japan,   2016 09 14
  • Determination of selenium in sea water by hydride generation -ICPOES, NAKAGUCHI Yuzuru, FUKUDA Yuki, KOTERA Saya,   2016 05 27
  • The Atmospheric Input of Bioactive Trace Metals in the Japan Sea, NAKAGUCHI Yuzuru, TAKADA Koichi, Asia Oceania Geosiences Society 2014,   2014 07 28
  • Mercury concentrations in biological materials of Japan(1) =Mercury concentration in brown rice and tree frog in Japan,   2005 06
  • Selenium in the Japan Sea Proper Water,   2001 03

Misc

  • Selenium speciation in pore water in marginal sea sediments, Bull. Soc. Sea Water Sci., Jpn., 61, 123, 131,   2007 02 , 10.11457/swsj1965.61.123
  • Study of the characterization of the water-soluble fluorescent substances in rainwater and airborne particulate matter by using three-dimensional excitation emission spectrometry, Science and technology, 18, 41, 46,   2006 02
  • Fluorescence Quenching Studies of Eu-Humic Complexes by Three-Dimensinal Excitation Emission Matrix Spectroscopy, Analytical Sciences, 17, p.i1585-i1588,   2001
  • Collection and Analysis of Gaseous and/or Fine Particulate Metal Compounds in the Atmosphere, Analytical Sciences, 17, p.i1589-i1592,   2001
  • Characterization and origin of chemical components in the submarine groundwater discharge in Toyama Bay, Chikyukagaku, Vol.39, 119-130,   2005
  • Trace element's speciation and the oxidation-reduction condition in the Eastern Pacific Ocean sediments, Kaiyo Monthly, Vol.39, 96-103,   2005
  • Dissolved selenium species in the Sulu Sea, the South China Sea and the Celebes Sea, Geochemical Journal, Vol.38, 571-580,   2004 , 10.2343/geochemj.38.571
  • Characterization and temporal variation of dissolved organic matter along 175E in the Western North Pacific Ocean 1995 and 1996, Bulletin of the Society of Sea Water Science, Japan, 56, 306-315,   2003 , 10.11457/swsj1965.57.306
  • Air Pollution by Concrete Dust from the Great Hanshin Earthquake, Journal of Environmental Quality, 31, 718-723,   2002
  • Distribution of dissolved Selenium Species in the Eastern Indian Ocean, Bulletin of the Society of Sea Water Science, Japan, 55, 3, 175, 182,   2001 , 10.11457/swsj1965.55.175
  • Anomalous distribution of dissolved organic carbon in the Sea of Japan, Geochemical Journal, 35, 355-364,   2001 , 10.2343/geochemj.35.355
  • Determination of chromium, copper, iron, manganese and lead in human hair by graphite furnace atomic absorption spectrometry, XN Dong, Y Nakaguchi, K Hiraki, ANALYTICAL SCIENCES, 14, 4, 785, 789,   1998 08 , 10.2116/analsci.14.785
    Summary:The use of a combined mixed magnesium(Mg)-rhodium(Rh) chemical modifier allows a compromise higher pyrolysis temperature to be used for the simultaneous detection of chromium (Cr), copper (Cu), iron (Fe), manganese (Mn) and lead (Pb) in various human hairs by graphite furnace atomic absorption spectrometry (GFAAS). The recommended pyrolysis temperature for all of the analyte elements is 1000 degrees C (ashing) and 2800 degrees C (atomizing). Nitric acid (HNO3) and perchloric acid (HClO4) were used for the digestion of all human-hair samples. The detection limits (3 sigma, ng g(-1)) were 0.3 for chromium, 0.1 for copper, 0.4 for iron, 0.2 for manganese and 0.1 for lead, respectively. The accuracy and precision were examined by analyzing a certified reference material (NIES CRM No.13 Human Hair). All of the analytical results obtained by the proposed method were in good agreement with the certified values. The relative standard deviation (RSD) was less then 8 %.
  • Quantitative analysis of human hair for selenium(IV), selenium(VI) and total selenium by hydride-generation atomic absorption spectrometry, XN Dong, Y Nakaguchi, K Hiraki, ANALYTICAL SCIENCES, 13, 2, 195, 198,   1997 04 , 10.2116/analsci.13.195
    Summary:Optimized procedures were established for the determination of total Se, organic Se, Se(IV), and Se(VI) in human hair by means of hydride-generation atomic absorption spectrometry (HGAAS), respectively. Using this method, the total Se content in a hair sample was determined through pretreating the sample with nitric acid-perchloric acid, and then reducing Se(VI) to Se(IV) with 6.0 mol dm(-3) hydrochloric acid; however, for individual Se(IV), Se(VI) or soluble Se, after the hair sample was immersed into water and disrupted ultrasonically for 8 h at room temperature, 2,3-diaminonaphthalene (DAN) reagent was added to extract Se(IV). The sum of Se(IV) and Se(VI) was determined by extracting Se(IV) after reducing all of the Se(VI) into Se(IV) with the addition of potassium bromide. Se(VI) was obtained by subtracting Se(IV) from the sum of Se(IV) and Se(VI). The content of organic Se in the hair sample was calculated by subtracting Se(IV)+Se(VI) from the total Se. The detection limit of the method was 0.3 ngSe cm(-3), and the average precision (relative standard deviation) was less than 5% (n=6).
  • Species and concentrations of selenium and nutrients in Tanabe Bay during red tide due to Gymnodinium nagasakiense, Yuichi Koike, Yuzuru Nakaguchi, Keizo Hiraki, Terufumi Takeuchi, Tomoyoshi Kokubo, Takashi Ishimaru, Journal of Oceanography, 49, 6, 641, 656,   1993 11 , 10.1007/BF02276749
    Summary:A red tide due to Gymnodinium nagasakiense was observed in August 1988 in Tanabe Bay, Wakayama Prefecture, Japan. The maximum cell concentration of G. nagasakiense reached 1×105 cells ml-1 at the surface water. From May to September 1988, the following were monitored: water temperature, salinity, chlorophyll a, D.O., dissolved nutrients (NO2-N, NO3-N, NH4-N, PO4-P DON, DOP), particulate nutrients (PON, POP) and three dissolved selenium species [Se(IV), Se(VI), Organic Se]. Dissolved inorganic nitrogen (NO3-N, NH4-N) decreased but PON, POP, DON, DOP and inorganic phosphate increased at the peak of the bloom. The concentration of organic selenium increased up to the bloom initiation period which started on 5 July, and then the concentration of Se(IV) increased as the concentration of organic selenium decreased at the peak of the bloom (3 August). The strong relationship was found between the concentration of Se(IV) and the cell concentration of G. nagasakiense (r2=0.98). The Se(IV) requirement of G. nagasakiense was 2.89×10-17 moles cell-1, which was agreed well with 4.4×10-17 moles cell-1 found in a laboratory experiment on G. nagasakiense using selenium spiked artificial sea water medium. The average ratio of Se(IV) to dissolved inorganic nitrogen (DIN) during the red tide bloom was 1:1441, the ratio of Se(IV) to DIN at the surface with the maximum cell concentration of G. nagasakiense of 1×105 cells ml-1 was 1:137. These results suggested that selenium may play an important role in red tide outbreak of G. nagasakiense. © 1993 Journal of the Oceanographic Society of Japan.
  • Selenium(IV), selenium(VI) and organic selenium in Lake Biwa, the Yodo River and Osaka Bay, Geochemical Journal, 27,367-374,   1993 , 10.2343/geochemj.27.367
  • Vertical profiles of dissolved selenium in the North Pacific, Geochemical Journal, 25,   1991 , 10.2343/geochemj.25.45
  • Determination of seleno-amino acid in natural water sample, Geochemical Journal, 24,   1990 , 10.2343/geochemj.24.255
  • Determination of Trace Vanadium by Addition of Both Sodium Selenite and Calcium Chloride with Polarized Zeeman Effect Graphite Furnace Atomic Absorption Spectrometry, Keizo Hiraki, Yuzuru Nakaguchi, Michitaka Morita, Hideharu Kitamaki, Analytical Sciences, 2, 6, 561, 566,   1986 , 10.2116/analsci.2.561
    Summary:A method for the determination of trace amounts of vanadium was developed by utilizing a chemically enhanced interference in a graphite furnace. The addition of both sodium selenite and calcium chloride was investigated for the formation of chemical species that atomize easily. The effects of both sodium selenite and calcium chloride concentrations were investigated. The highest absorbance was observed at 0.8% sodium selenite and 0.5% calcium chloride solution. The optimum heating cycle was: first drying at 80-160°C for 30 s, ashing at 1800°C for 30 s, and atomizing at 2900°C for 7 s. The effect of various acids on vanadium absorbance was investigated. Nitric acid gave a higher absorbance and a lower coefficient of variation than hydrochloric acid or perchloric acid. The effects of diverse ions were also examined. Large interference was observed with alkali and alkaline earth metals. A pyrolitic graphite furnace was the most suitable for atomizing vanadium. The method was used to determine the vanadium in a certified reference material, “NIES (National Institute for Environmental Studies) Mussel”. The chemical species formed in a graphite furnace during the ashing process were examined by powder X-ray diffraction in order to study the mechanism involved in the procedure. © 1986, The Japan Society for Analytical Chemistry. All rights reserved.
  • Fluorometric Selenium(VI) Determination of Inorganic Selenium(IV), and Organic Selenium in Natural Waters, Yuzuru Nakaguchi, Keizo Hiraki, Yuzo Fukunaga, Yasuharu Nishikawa, Tsunenobu Shigematsu, Yuzo Tamari, Analytical Sciences, 1, 3, 247, 252,   1985 , 10.2116/analsci.1.247
    Summary:A method for the simultaneous determination of selenium species such as selenium(IV), selenium(VI) and organic selenium tn natural waters has been developed in this paper, Selenium(IV) was fluorometrically determined after extracting the complex of 2,3-diaminonaphthalene (DAN) into cyclohexane. Selenium(VI) In the sample was first reduced to the quadrivalent state by adding potassium bromide in 1.3 M hydrochloric acid solution, then the total inorganic selenium was determined by the same technique as the determination of selenium) IV). The amounts of selenium(VI) can be calculated by subtracting the amounts of selenium(IV) from the total inorganic selenium. Organic selenium was determined as follows: all selenium, including inorganic selenium(IV), selenium VI), and organic selenium, was coprecipitated with tellurium(IV), and then reduced to elemental selenium and tellurium by hydrazine sulphate in acid solution (4 M HCI for river water samples 1 -2 M HCI for sea water samples). The elemental selenium and tellurium were dissolved in a mixture of nitric acid and hydrochloric acid, reduced to selenium(IV) by boiling with 6 M hydrochloric acid, and also determined by the DAN fluorometry. The amount of organic selenium was estimated by substracting the amount of both selenium) IV) and selenium(VI) from the total amount of selenium determined by this coprecipitation method. Interesting results were obtained from applying this method to river- and sea-water samples. © 1985, The Japan Society for Analytical Chemistry. All rights reserved.

Research Grants & Projects

  • Study on trace elements in the atmospheric aerosols
  • Study on the analysis of dissolved organic carbon in Seawater
  • Speciation of trace element in natural water