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Volume 48, Issue 9
Displaying 1-8 of 8 articles from this issue
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Fumio MIZUTANI1999 Volume 48 Issue 9 Pages 809-821
Published: September 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSBiosensors combining the specificity of enzymatic reactions with electrochemical signal transduction have attracted increased interest in the last decades. Particular efforts in this field have recently been directed to the development of simple, rapid and reproducible procedures for constructing biosensors. Techniques for preparing chemically modified electrodes (CMEs) are useful for this purpose.
This review focuses upon the preparation of biosensors of the CME-type, and emphasized innovative biosensor designs for exhibiting such high-performance characteristics as rapid response and high sensitivity.View full abstractDownload PDF (2505K) -
Toshio SHIGEMATSU, Koji SHIKANO, Hiroki YONEZAWA1999 Volume 48 Issue 9 Pages 823-828
Published: September 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSFirst, instrumental methods were studied to develop the charged particle activation analysis of oxygen, nitrogen, carbon and boron in purified iron. Carbon and nitrogen could be determined instrumentally by bombardment with lower than 4 MeV deuterons and 5.5 MeV protons so as to avoid interference of the radionuclides induced from the iron matrix. Chemical separations containing substoichiometric precipitation were developed for oxygen and boron at the 0.1 ppm level. These analytical methods were applied to the same iron purified for oxygen analysis. The accuracy of such standardization methods as the numerical integration and the average cross section, and the influence of co-existing elements, such as sodium, are also discussed.View full abstractDownload PDF (886K) -
Atsushi FURUSAKI1999 Volume 48 Issue 9 Pages 829-834
Published: September 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe mass balance of heavy metals (iron, copper, zinc and cadmium) contained in the mid-gut gland (MGG) of scallops in the incineration process was studied. The metal contents in bottom ash, deposited on the tube wall, fly ash, and absorption solutions were measured by atomic absorption spectroscopy (AAS). Although wet MGG contained about an average of 20 ppm cadmium, about 57% was vaporized when heated at 900°C in air. Most of the vaporized cadmium was deposited on the tube wall, and a certain amount of it was detected from fly ash. When MGG was heated in nitrogen, the remaining cadmium ratio was around 10%, and cadmium of about 83% was detected from the tube wall, 6% from the fly ash, and 1.8% from the absorption solutions. In the case of heating cadmium metal, only oxidation proceeded in the air atmosphere, while cadmium vaporized nearly 100% in the nitrogen. It was thus considered that the vaporization of cadmium found during the incineration of MGG was caused by a partial insufficiency of oxygen was generated when the organic mass was burned.View full abstractDownload PDF (863K) -
Masamitsu FUKUDA, Kazutoshi SHIMURA, Minoru TAKEYA1999 Volume 48 Issue 9 Pages 835-840
Published: September 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSHigh-purity ruthenium metal is only slightly soluble in almost all acidic regents. In this study, we developed decomposition techniques to dissolve Ru metal. We applied a Ru-Ga compound method for the analysis of sodium and potassium because of this compound's form at temperature lower than the boiling points of alkali-metal elements. The Ru-Ga compound was formed by 600°C in the atmosphere, and was decomposed using a HCl-HNO3 solution. The Ru matrix in the sample solution was removed as RuO4 by a H2SO4-HClO4 mixed solution at 350°C. The Ga matrix coexisted in the final solution, though any coexistent Ga was not influenced during measurement of sodium and potassium. All other impurities were determined using the Ru-Sn alloy method. The Ru-Sn alloy was formed at 1400°C in nitrogen gas; it could be dissolved and expelled with a HCl-HNO3 and H2SO4-HClO4-HBr mixture. Appropriate methods, including FE, GF-AAS and ICP-MS, were applied for the determination of Na, K, Fe, Al, Mn, Ni, Cu, Ag, Th and U. The detection limits obtained by these methods were from 0.3 μg g-1 to 0.02 ng g-1.View full abstractDownload PDF (966K) -
Motoshi NAKAMURA, Hiroshi TANIGUCHI, Shinkichi YAMADA, Takushi ITOU1999 Volume 48 Issue 9 Pages 841-846
Published: September 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSCarbaryl and its main metabolite, 1-naphthol, were determined simultaneously using a synchronous second-derivative fluorimetric method. The presence of cetyltrimethylammonium bromide resulted in a four-fold increase in the fluorescence intensity of 1-naphthol together with a large bathochromic shift of the emission spectrum, ca. 100 nm. The synchronous second-derivative spectra of carbaryl and 1-naphthol in the mixture in the presence of CTAB were completely separated by changing the synchronous wavelength interval; with 63 nm the second-derivative spectra of carbaryl were recorded, while with 163 nm those of 1-naphthol appeared. The intensities in the spectra were proportional to the concentration of carbaryl and 1-naphthol. The calibration graphs were linear up to at least 1 × 10-6 M, and both the correlation factors and detection limits were 0.997, 2.61 × 10-8 M for carbaryl and 0.999, 2.87 × 10-8 M for 1-naphthol. Carbaryl and 1-naphthol were completely recovered with a Sep Pak Plus C18 cartridge from some environmental water samples with an adjusted pH of below 6.5, and were successfully determined by the proposed method.View full abstractDownload PDF (796K) -
Shigeru TERASHIMA, Masahiro TANIGUCHI1999 Volume 48 Issue 9 Pages 847-854
Published: September 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA five-step sequential chemical-extraction scheme is described for the analysis of Au in geological reference samples by solvent extraction/graphite furnace AAS. Each chemical fraction is operationally defined as follows: 1) 0.1 M ammonium chloride for the fraction of exchangeable form; 2) 0.1 M HCl- 0.1 M KI for the fraction of amorphous form; 3) 0.1 M HCl- 0.2 M KI at about 100°C for the fraction of metal form; 4) a mixture of HNO3 and HCl for the fraction of aqua regia soluble form; and 5) a mixture of HNO3, HCl and HF for the fraction of residual form. The relative standard deviations for Au at levels of 0.6 and 50 ng, with a few exceptions, were 33 and 6%, respectively. The detection limit was approximately 0.2 ppb for a 0.5 g sample. Satisfactory agreement was observed between the sum of the Au values from exchangeable to residual fractions and the reported total Au values. The analytical results of Au for 11 geological reference samples, such as igneous rocks, sediments, soils and ores were tabulated, and the geological and mineralogical features are discussed.View full abstractDownload PDF (1297K) -
Hitoshi YAMAGUCHI, Shinji ITOH, Shukuro IGARASHI, Kunishige NAITOH, Ry ...1999 Volume 48 Issue 9 Pages 855-859
Published: September 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA preparation method of a solution sample in fluorescent X-ray spectroscopy has been developed. There is a considerable constraint in the drying and dropping process in the conventional method using a specially designed filter paper. In the present method for fixing filter paper on a sample holder, no problems, such as distortion or breaking of the filter paper, was caused when a sample solution was heated for drying. By reducing the thickness of the filter paper, the absorption of fluorescent X-rays could be suppressed for light elements. For heavy elements, it was possible to increase the quantity of the dropping sample by increasing the thickness and area of the filter paper. In addition, by using a separating filter paper or a functional filter paper, such as ion-exchange filter paper, it is possible to collect only the specified element. A performance enhancement of the analytical system and on extension of the fields of application can be expected.View full abstractDownload PDF (753K) -
Theingi KYAW, Toshiro WATANABE, Rong WEI, Takashi ITO1999 Volume 48 Issue 9 Pages 861-868
Published: September 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (1512K)
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