Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Volume 75 , Issue 9
Showing 1-16 articles out of 16 articles from the selected issue
  • Yusuke FUCHIWAKI, Naoki SASAKI, Izumi KUBO
    2007 Volume 75 Issue 9 Pages 709-714
    Published: September 05, 2007
    Released: March 20, 2012
    CAT is a triazine moiety that has been used as one of the most popular herbicides, and is reported to be an endocrine disrupting chemical. To detect aqueous CAT specifically at low concentrations regulated regally, an electrochemical sensing system for CAT was developed by coupling a molecularly imprinted polymer for CAT (CAT-MIP) packed column and an electrochemical analyzer. We have already reported the preparation of CAT-MIP as an artificial sensor receptor. In order to establish the electrochemical sensing system of CAT, we fabricated an amalgamated gold electrode which was alloyed with mercury. The amalgamated gold electrode could detect the largest reductive current of CAT at pH 3.0 in 0.1 M KCl, up to 30 µM. The detection procedure of this sensing system is composed of a solid phase extraction with the CAT-MIP column and electrochemical determination of CAT in the eluent from the column. With the sensing system, CAT was detected specifically in aqueous samples by washing non-specific adsorption to the CAT-MIP column with dichloromethane. Fifteen nM of CAT, as legally regulated in Japan, was detected with the system.
    Download PDF (970K)
  • Nagahiro HOSHI, Toshihiro HARADA, Masashi NAKAMURA, Daiki NOZU
    2007 Volume 75 Issue 9 Pages 715-718
    Published: September 05, 2007
    Released: March 20, 2012
    Chlorobenzene was electrolyzed on polycrystalline platinum electrode in acetonitrile with various water concentrations at −3.02 V(vs. Fc/Fc+). Formation rate of the reduction products depend on water concentration remarkably. Benzene is a main product at [H2O]≤0.3 mol dm−3. At [H2O]≥0.35 mol dm−3, toluene is obtained as well as benzene. Partial current density of toluene gives maximum at [H2O]=0.44 mol dm−3. Formation of toluene closely relates with production of methane resulting from the decomposition of acetonitrile.
    Download PDF (514K)
  • Hiroshi YAMAMURA, Saori TAKEDA, Katsuyoshi KAKINUMA
    2007 Volume 75 Issue 9 Pages 719-724
    Published: September 05, 2007
    Released: March 20, 2012
    The relationship between electrical conductivity and dielectric relaxation was investigated for 20 atom % Nd doped CeO2 (Ce0.8Nd0.2O2−δ), which is a typical oxide-ion conductor. Computer simulation clarified that the anomaly large dielectric constant (εr′) originated from the superimposition of both Debye-type polarization and interfacial polarization between electrolyte and electrode. Two kinds of the Debye-type relaxation appeared equal and above 773 K, which were ascribed to defect associates, (NdCe′-VO••) and (NdCe′-VO••-NdCe′)×. The frequency dependence of ac conductivity (σac) was successfully explained by analyzing the dielectric loss factor (εr″). The σac values in high temperature and high frequency regions agreed with dc conductivity (σdc). The activation energy for σdc agreed with that for high frequency Debye-type polarization.
    Download PDF (700K)
Technological Report
  • Yuichi SHOJI, Nozomu SATO, Kazuo UNOKI, Shukuji ASAKURA
    2007 Volume 75 Issue 9 Pages 725-730
    Published: September 05, 2007
    Released: March 20, 2012
    Volatile Organic Compounds (VOCs), such as carbon tetrachloride(CCl4), tetra-chloro-ethlene (CCl2CCl2) and 1,2-dichloroetane (CH2ClCH2Cl), were decomposed by using molten alkaline hydroxide (NaOH) without any oxidizing gas such as air. Decomposition capability was evaluated with both decomposition efficiency of VOCs and concentrations of secondary compounds regenerated in a gas phase.
    It was found that these gases reacted remarkably with molten NaOH above 600°C and the decomposition efficiencies were above 99.9% by means of the gas chromatograph mass spectroscopy (GC-MS method). Thirteen kinds of organic chlorides in a gas phase were also measured, in accordance with JIS-K-0125 by GC-MS, to be found that each concentration was below the detective limit (0.05 vol.ppm). Methane and hydrogen were detected in exhaust gas as the other secondary regenerates, as were estimated with previous thermo-dynamical calculations by MALT-2.
    Based on these results, the authors estimated adequate chemical decomposition reactions.
    Download PDF (735K)