Seiji Nakatsuka
Kyoto University
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Featured researches published by Seiji Nakatsuka.
Analytical Chemistry | 2008
Yoshiki Sohrin; Shouhei Urushihara; Seiji Nakatsuka; Tomohiro Kono; Eri Higo; Tomoharu Minami; Kazuhiro Norisuye; Shigeo Umetani
GEOTRACES is an international research project on marine biogeochemical cycles of trace elements and their isotopes. GEOTRACES key trace metals in seawater are Al (8-1000 ng/kg), Mn (4-300 ng/kg), Fe (1-100 ng/kg), Cu (30-300 ng/kg), Zn (3-600 ng/kg), and Cd (0.1-100 ng/kg), of which global oceanic distribution will be determined on a number of research cruises. This work introduces a novel method of solid-phase extraction to determine Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb in seawater by adjusting the pH of the sample to 6 and carrying out a single preconcentration step. The trace metals were collected from approximately 120 mL of seawater using a column of a chelating resin containing the ethylenediaminetriacetic acid functional group and eluted with approximately 15 mL of 1 M HNO3. Mn and Fe in the eluate were measured by inductively coupled plasma mass spectrometry (ICPMS) using the dynamic reaction cell mode, and the other metals were measured using the standard mode. Using this procedure, the trace metals were collected quantitatively, while >99.9% of alkali and alkaline earth metals in seawater were removed. The procedural blank was <7% of the mean concentration in deep ocean waters, except 16% for Pb. The overall detection limit was <14% of the mean concentration in deep ocean waters. The RSD was <9%. Our values for the trace metals in the certified reference materials of seawater NASS-5 and nearshore seawater CASS-4 agreed with the certified values (except that there is no certified value for Al). This method was also successfully applied to the reference materials of open-ocean seawater produced by the SAFe program. Our Fe concentrations were 5.9 +/- 0.7 ng/kg for surface water (S1) and 50.4 +/- 2.9 ng/kg for deep water (D2), which are in agreement with the interlaboratory averages of 5.4 +/- 2.4 and 50.8 +/- 9.5 ng/L, respectively. The data for other metals were oceanographically consistent.
Chemosphere | 2012
Sou Matsunaga; Satoru Chatani; Seiji Nakatsuka; Dai Kusumoto; Katsuyoshi Kubota; Yasuhiro Utsumi; Tsutomu Enoki; Akira Tani; Tsutom Hiura
Reactive volatile organic compounds (VOCs) are known to affect atmospheric chemistry. Biogenic VOCs (BVOCs) have a significant impact on regional air quality due to their large emission rates and high reactivities. Diterpenes (most particularly, kaur-16-ene) were detected in all of the 205 enclosure air samples collected over multiple seasons at two different sites from Cryptomeria japonica and Chamaecyparis obtusa trees, the dominant coniferous trees in Japan,. The emission rate of kaur-16-ene, was determined to be from 0.01 to 7.1 μg dwg(-1) h(-1) (average: 0.61 μg dwg(-1) h(-1)) employing branch enclosure measurements using adsorbent sampling followed by solid phase-liquid extraction techniques. The emission rate was comparable to that of monoterpenes, which is known major BVOC emissions, collected from the same branches. In addition, total emission of kaur-16-ene at 30°C was estimated to exceed that of total anthropogenic VOC emissions.
Journal of Oceanography | 2007
Atsushi Tsuda; Shigenobu Takeda; Hiroaki Saito; Jun Nishioka; Isao Kudo; Yukihiro Nojiri; Koji Suzuki; Mitsuo Uematsu; Mark L. Wells; Daisuke Tsumune; Takeshi Yoshimura; Tatsuo Aono; Takafumi Aramaki; William P. Cochlan; Maki Hayakawa; Keiri Imai; Tomoshi Isada; Yoko Iwamoto; William Keith Johnson; Sohiko Kameyama; Shungo Kato; Hiroshi Kiyosawa; Y. Kondo; Maurice Levasseur; Ryuji J. Machida; Ippei Nagao; Fumiko Nakagawa; Takahiro Nakanishi; Seiji Nakatsuka; Akira Narita
Journal of Oceanography | 2008
M. Lutfi Firdaus; Kazuhiro Norisuye; Yusuke Nakagawa; Seiji Nakatsuka; Yoshiki Sohrin
Analytica Chimica Acta | 2007
Seiji Nakatsuka; Kei Okamura; Kazuhiro Norisuye; Yoshiki Sohrin
Deep-sea Research Part Ii-topical Studies in Oceanography | 2007
Kazuhiro Norisuye; M. Ezoe; Seiji Nakatsuka; Shigeo Umetani; Yoshiki Sohrin
Atmospheric Environment | 2011
Satoru Chatani; Tazuko Morikawa; Seiji Nakatsuka; Sou Matsunaga; Hiroaki Minoura
Journal of Oceanography | 2012
Abigail Parcasio Cid; Seiji Nakatsuka; Yoshiki Sohrin
Deep-sea Research Part Ii-topical Studies in Oceanography | 2009
Seiji Nakatsuka; Kei Okamura; Shigenobu Takeda; Jun Nishioka; M. Lutfi Firdaus; Kazuhiro Norisuye; Yoshiki Sohrin
Atmospheric Environment | 2010
Sou Matsunaga; Satoru Chatani; Tazuko Morikawa; Seiji Nakatsuka; Jeeranut Suthawaree; Yosuke Tajima; Shungo Kato; Yoshizumi Kajii; Hiroaki Minoura