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Volume 54, Issue 4
Displaying 1-10 of 10 articles from this issue
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Review
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Toshiyuki OSAKAI, Hajime KATANO2005 Volume 54 Issue 4 Pages 251-266
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSRecent developments in the electroanalytical chemistry at an oil|water interface have been reviewed by citing literature published mainly in 2002 and 2003. Regarding ion-transfer reactions, some important methodologies have been introduced, which include the uses of new organic solvents and room-temperature molten salts as oil-phase solvents, a three-phase (oil|solid electrode|water) system for the determination of standard Gibbs ion-transfer energies, and some controlled-potential electrolytic cells. Using these new as well as conventional methods, extensive studies have been carried out on the facilitated transfer of cations and anions, the distribution reactions of drugs, and the interfacial transfer of ionic polymers. A previous introduction of scanning electrochemical microscopy has revitalized the kinetic study of electron transfer at oil|water interfaces. A further introduction of new methods, including the electron conductor separating oil-water system, has facilitated the mechanistic study of electron-transfer reactions. Much interest has also been paid to photo-induced electron transfers, the electrodeposition of metallic nanoparticles, etc. In addition, adsorption reactions at oil|water interfaces have been studied by means of in situ electrochemical spectroscopy, and the instability of an oil|water interface has been discussed concerning the relevance of interfacial adsorption of a transferring ion.
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Account
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Hideaki HISAMOTO2005 Volume 54 Issue 4 Pages 267-278
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSA recent microfabrication technology opened the new application field such as micro total analysis systems (Micro TAS) or microreactors. These systems employed physical characteristics provided by the liquid microspace, involving short diffusion distance, large surface to volume ratio, or small heat capacity. In contrast to these works, we focused on the chemical functions of highly-selective molecular recognition molecules or functional dyes of which we have been developed, to be integrated into microfluidic chemical sensing systems. The present paper describes our recent results concerning chemical sensing systems based on microfluidic devices. Here, a multi ion sensing system based on the intermittent reagent pumping and ion-pair extraction, a new biosensing scheme based on the enzyme-immobilized polymer membrane, and a novel multi ion sensing scheme based on capillary-assembled microchip, are presented.
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Research Paper
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Toshiyuki MIYAUCHI, Kousuke UOE, Tokuhisa ISIKAWA, Atuo TANAKA, Hidehi ...2005 Volume 54 Issue 4 Pages 279-284
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSThe new type Fe(II) compound, Iron(II)-μ-ethyl phosphate-(2-)-o,o'-ethyl phosphonate was prepared by the reaction of diethyl phosphonate with ferric nitrate in an acetonitorile solvent for 2 hours. Fe(II) compound reacted with 1-Naphthol to produce a reddish-purple color (λmax 510 nm). The fundamental conditions of the spectrophotometric method for the determination of 1-naphthol with Fe(II) compound were investigated. Beer’s law was obeyed over a concentration range of 2 ~ 10 mg/l of 1-naphthol. The optimum pH range was 2.0 ~ 3.5, and the apparent molar absorptivity was 1.46 × 103 l mol−1 cm−1 at 510 nm. The determination of 1-naphthol was not interfered up to 100-times concentration of phenol and 2-naphthol in their presence, respectively. Mono-substitution products of phenol and 2-naphthol were permissible at a one-time concentration of 1-naphthol. The determination of 1-naphthol in the mixtures of 1-naphthol and 2-naphthol was also investigated.
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Technical Paper
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Hiroki YAMAZAKI, Ryuji TOKUGAWA, Masatoshi OSANAI, Touru TORII, Yoko M ...2005 Volume 54 Issue 4 Pages 285-290
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSThis paper describes the development and testing of a single-use multi-sensor system for measuring the concentrations of ions used in nutrition for crops. The sensor consists of a conductive paste material on an insulating PET film; selective ligands can simultaneously measure the concentration of many nutrient ions. It includes electrodes, a heater, a calibration fluid and a waste container, and gives test results within 3 minutes. By using two kinds of sensor systems, pH and EC are measured, together with the concentrations of K+, Ca2+, Mg2+, H2PO4−, NO3− and NH4+. This single-use multi-sensor system is reliable, fast, and easy and inexpensive to use. The single-use multi-sensor system and reference analyzers showed a good correlation for a wide variety of nutrient components.
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Yasutada SUZUKI, Takayuki ITO, Tsugio FUKASAWA, Susumu KAWAKUBO, Masaa ...2005 Volume 54 Issue 4 Pages 291-295
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSTwo colorimetric instruments, a photometric titrator and an absorptiometric detector for flow-injection analysis, were developed for experiments in under-graduate course. They were based on the colorimeter using a light-emitting diode (LED) as a light source. The photometric titrator had a holder for a 2-cm cell and a magnetic stirrer. This titrator was applied to titration of Cu(II) and Ca(II) with EDTA. Cu-ammine complex was produced and its absorbance was measured with a red LED (630 nm). The titration curve obtained by this titrator was better than the one obtained by a conventional titrator. Moreover, the volume of the sample and reagents were greatly reduced due to the built-in stirrer. On the other hands, the detector for FIA had a circuit to output flow-signal to a recorder. This detector was applied to the FIA determination of iron in an aluminum sample with 1,10-phenanthroline. Dual-wavelength measurements were performed to reduce the noise caused by peristaltic pumps. From the absorbance at the wavelength absorbed by iron(II) chelate (530 nm), background signal measured at 630 nm was subtracted. The obtained results were good agreement with those by atomic absorption spectrometry. Both instruments had small dimensions (125 × 90 × 60 mm) and were low power consumption.
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Note
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Mikio ISHIKURO2005 Volume 54 Issue 4 Pages 297-300
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSProper dissolution procedures for Fe-Ga-P-C-B-Si bulk metallic glass were investigated for an elemental determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). Metallic samples are usually dissolved with several kinds of mineral acids. For a Fe-Ga-P-C-B-Si bulk metallic glass sample, hydrofluoric acid or hydrochloric acid was not used, because silicon, phosphorus and boron in samples were volatilized. When the sample was dissolved with a mixture of hydrochloric acid and nitric acid, small amounts of black-colored insoluble residue remained. However, by a microwave-assisted dissolution method, the sample was completely dissolved with a mixture of hydrochloric acid, nitric acid and water. Analytical results obtained by ICP-OES had good reproducibility and the total content became almost 100%.
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Kiyoshi NAKAGAWA2005 Volume 54 Issue 4 Pages 301-305
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSTrace amounts of nickel, cobalt and manganese in serum were determined by graphite-furnace AAS after a treatment with a high concentration (7.5 M) of ammonia solution. Serum was diluted with ammonia water 2 ~ 4 times because the content of these elements in serum was very low and close to the detection limit. This diluted solution was injected with hydrogen peroxide into a graphite furnace. A surfactant was unnecessary because the viscosity of the sample solution was reduced by the treatment with ammonia water. The temperature of the graphite furnace used to make the sample oxidize and to dry it was kept at 80 ~ 110°C for 180 s. As a results, the Charateristic Mass (pg/0.0044 Abs) became smaller than that of the recommended method. Ni, Co and Mn concentrations in seronorm™ reference human serum were estimated to be 5.49, 1.09 and 10.1 μg/l with % RSD values of 1.1, 1.6 and 5.3, respectively. These values agreed well with the certified values of Ni, Co and Mn.
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Analytical Report
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Toshiyuki HOBO, Mariko MURAYAMA, Shozo ASADA, Hiroyuki IGAKI, Takashi ...2005 Volume 54 Issue 4 Pages 307-319
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSThe Japan Society for Analytical Chemistry has developed two new certified reference materials (CRMs) for dioxins: coplanar PCBs and 1 ~ 10 chlorinated PCB homologues. A project team has been organized to prepare 2 kinds of marine sediment and to certify the concentration of dioxins and polychlorobiphenyls. An interlaboratory comparison test was performed by participants from 24 laboratories. In a statistical analysis, the z scores in robust method were applied to reject outliers, followed by the usual statistical procedure. The presented CRMs are expected to be useful for the quality assurance and quality control of dioxins analysis.
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Hideshi ISHII, Naoki SATO, Motonobu KAWANO, Takamasa MESAKI, Jun KAWAI2005 Volume 54 Issue 4 Pages 321-324
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSX-ray fluorescence analysis on rice (brown rice, white rice and wash-free rice) and rice bran has been performed by using a dry battery X-ray fluorescence (XRF) spectrometer in combination with a pyroelectric X-ray generator and a potable Si PIN X-ray detector. As a reference, a similar analysis with a commercial energy dispersion XRF spectrometer achieved the detection of K, Mn, Fe, S, Cu, Zn and Rb. The difference of the XRF spectra revealed that K, Fe, Mn, S and Rb were contained in rice bran. Nevertheless, the dry battery spectrometer detected only K, Mn and Fe; the measured abundances of these elements in rice and rice bran were almost similar. This difference of detected elements is mainly due to the difference between characteristic X-rays from both X-ray sources, and not due to the difference in the intensities of excited X-rays. Thus, the dry battery XRF spectrometer has sufficient capability for the XRF analysis on crops as commercial spectrometers, notwithstanding the low power of the X-ray outputs.
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Toshihide MATSUDA, Tsuyoshi HIRAKAWA, Hiroshi SAKUGAWA2005 Volume 54 Issue 4 Pages 325-329
Published: 2005
Released on J-STAGE: May 27, 2005
JOURNAL FREE ACCESSA field-based intercomparison study of a commercial open-path differential optical absorption spectrometer (DOAS) and conventional point monitoring techniques for ozone (O3), nitrogen dioxide (NO2) and sulfur dioxide (SO2) was conducted from August to September, 1999, in Higashi-Hiroshima, Hiroshima prefecture. O3, NO2 and SO2 were measured every 10 minutes by an ultraviolet-ray absorption method, a chemiluminescence method, and a fluorescence method, respectively, while all of these three gases were simultaneously monitored every 20 minutes by the DOAS system (DOAS 2000, Thermo Electron Nippon Co. Ltd., Japan). Very good correlations were found for O3 (r2 = 0.96) and SO2 (r2 = 0.93), while a slightly lower correlation existed for NO2 (r2 = 0.80). The average concentrations of these gases monitored by the DOAS system were 1.1, 1.2, 1.6 times higher than those measured by conventional point monitors, respectively. Vehicle emissions from the surrounding area of the monitoring site caused atmospheric inhomogeneities, which were involved in the lower correlation for NO2 by causing differences in the analytical values of the two methods. A much higher slope of SO2 (1.6) was considered to result from the use of an inaccurate standard spectrum in DOAS analysis, which was prepared from 100 ppm level reference gas. Precipitation (0.5 ~ 35.0 mm h−1) and the relative humidity (25.6 ~ 99.9%) didn’t affect the DOAS measurements. Fog interrupted the DOAS measurements of all compounds in during several periods; it occurred when the relative humidity was kept over 99% for a few hours from midnight to morning. The mobile emitting source and the meteorological situations should be considered when monitoring is carried out by DOAS.
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