BUNSEKI KAGAKU
Print ISSN : 0525-1931
Volume 44, Issue 4
Displaying 1-13 of 13 articles from this issue
  • Jun KAWAI, Isao TANAKA, Hirohiko ADACHI
    1995 Volume 44 Issue 4 Pages 251-269
    Published: April 05, 1995
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    Approximations for calculating X-ray emission spectra and X-ray absorption spectra of solids and molecules are described. It is shown that the X-ray emission spectral profiles are well reproduced by the partial electron density of states calculations, and the X-ray absorption spectral profiles are well reproduced by the unoccupied electron densities for solids and molecules. Information contained in the X-ray spectra is discussed.
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  • Mitsuhiro MASUDA, Mitsuichi HANDA, Kazuhiko SAGARA
    1995 Volume 44 Issue 4 Pages 271-275
    Published: April 05, 1995
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    A simple high-performance liquid chromatographic method was developed for the determination of inositol in multivitamin preparations containing large amounts of sugars. The sample multivitamin preparation was separated on an acrylic amide column with acetone-water (7 : 3) as the mobile phase and an RI detector. The quantitations were achieved by the peak area ratio method using α-cyclodextrin as an internal standard. Inositol in the multivitamin preparations containing large amounts of sugars was determined successfully by the present method without any pretreatment.
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  • Gas electrode detector for gas chromatography. III
    Yoshimitsu SEO, Ken UMEMURA, Mitsunojo ICHISE
    1995 Volume 44 Issue 4 Pages 277-282
    Published: April 05, 1995
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    Selective detection and qualitative identification of sulfur compounds in gasoline were carried out by means of a gas electrode detector developed in our laboratory, which uses a sulfide electrode as sensor. Compounds in the sample are separated on a gas chromatographic capillary column using hydrogen as carrier gas. The components eluted from the column are passed through a silica pyrolysis tube (40 cm×0.4 mm i.d.) packed with silica wool and heated at 940°C By this treatment, sulfur compounds can be converted to hydrogen sulfide and hydrocarbon compounds to methane. The decomposition gases are blown upon a hand-twisted cotton thread which is in contact with the sensitive surface of the sulfide electrode. The absorption solution, pH 12.7, containing 0.1 M NaNO3 and 0.05 M NaOH flows (7 μl/min) through the cotton thread, where the hydrogen sulfide is dissolved in the absorption solution. The potentiometric output of the ionselective electrode is digitized and transferred to the microcomputer system. About 0.5 μl of gasoline containing 0.01 % (w/w) sulfur was injected without pretreatment such as extraction or enrichment. Thiophenic compounds were distinguished from nonthio phenic compounds by the difference in their thermal stability in silica pyrolysis tube, the retention time serving as a marker for qualitative identification. Nine sulfur compounds were identified. These include thiophene, dimethyl disulfide, 2-methylthiophene, 3-methylthiophene, ethyl methyl disulfide, 2, 5-dimethylthiophene, 2-ethylthiophene, diethyl disulfide, 2, 3-benzothiophene.
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  • Katsutoshi INOUE, Keisuke OHTO, Kazuharu YOSHIZUKA, Ryuji SHINBARU, Ke ...
    1995 Volume 44 Issue 4 Pages 283-287
    Published: April 05, 1995
    Released on J-STAGE: May 25, 2010
    JOURNAL FREE ACCESS
    Ethylenediaminetetraacetic acid-type chitosan (EDTA-type chitosan) was synthesized to examine its adsorption behavior for several base metal ions as well as a series of rare earth metals from dilute sulfuric acid solution. The EDTA type functional group was incorporated onto chitosan nearly quantitatively. Unlike adsorption with original chitosan, that with EDTA-type chitosan takes place at a lower pH than that with diethylenetriamine-pentaacetic acid-type chitosan (DTPA-type chitosan); for example, copper(II)was adsorped at pH=0 on EDTA-type chitosan but at pH=4 on original chitosan. The selectivity series for the adsorption of base metals was as follows: Cu2+ ≅ MoO22+ > Ni2+ > VO2+ > Zn2+ ≥ Co2+ > Al3+. The plots of the distribution ratio of trivalent rare earths against pH lie on straight lines with a slope of 3, suggesting that adsorption takes place by a cation-exchange mechanism. The apparent equilibrium constants for adsorption on EDTA-type chitosan were evaluated as well as those on DTPA-type chitosan. The sequence of the apparent equilibrium constants with a series of rare earths was roughly consistent with that of the stability constants in the case of EDTA-type chitosan as well as with DTPA-type chitosan. Consequently, EDTA and DTPA are still functional after immobilization on chitosan. The EDTA-type chitosan seems to exhibit promise for the mutual separation of adjacent rare earths except for middle rare earths.
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  • Toshihide IHARA, Yuko HANNO, Yoshio SUGIMOTO, Tatsuro NAKAGAMA, Toshiy ...
    1995 Volume 44 Issue 4 Pages 289-296
    Published: April 05, 1995
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    A new immobilization method for chiral stationary phases on porous silica gel for HPLC was developed. It is known that the hydrosilylation reaction proceed with great difficulty on the silica gel surface. It was, however, found that the reaction proceeds easily when using a highly hydrophobic platinum catalyst. Based on this finding, an immobilization method was developed, in which silylation is carried out first and then the chiral selector is subsequently introduced onto it by the hydrosilylation reaction. This preparation method has the unique feature that it is capable of covering the silanol groups efficiently. Optical resolution of DL-amino acids on the Pirkle-type chiral stationary phase prepared through the proposed method, gave excellent result. The separation factors obtained were the highest ever obtained, especially when the coverage density was very low. Further, the usefulness of this preparation method was tried to be elucidated through simulation by the molecular dynamics method.
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  • Takushi ITO
    1995 Volume 44 Issue 4 Pages 297-300
    Published: April 05, 1995
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    A flow-injection spectrofluorometric method was devised for the determination of gold (III) based on the fluorescent oxidized product of kojic acid. The maximum wavelengths of the excitation and emission spectra of the oxidized product are 375 and 495nm, respectively. The carrier solution (0.1M sodium chloride) and buffer solution (pH 7.5) containing 8×10-3 M kojic acid were each pumped at 1.5ml min-1. The length of the reaction coil was 1m. The present method allows the determination of 110μg ml-1 of gold (III) based on 100μl injection volume. The relative standard deviation of 1.2% (n = 9) was obtained at 3μg ml-1 of gold ( III ). The sample throughput was about 20h-1. Palladium does not interfere with up to 50-fold amounts under masking with nitrilotriacetic acid.
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  • Naobumi ÔI, Hajimu KITAHARA, Naoko KISU
    1995 Volume 44 Issue 4 Pages 301-305
    Published: April 05, 1995
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    The enantiomer separation of small amounts of amino acids and hydroxy acids by HPLC using chiral stationary phases and achiral derivatizing reagents was examined. Racemic dabsyl amino acids and pyrene-l-carbonyl hydroxy acids were well resolved on chiral stationary phases [VI] and [V], and excellent values of detection limits were obtained. The joint use of chiral stationary phases and achiral derivatizing reagents was found to be very effective for the separation and determination of small amounts of amino acid and hydroxy acid enantiomers by HPLC.
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  • Shigeru TAGUCHI, Tomoko GOKI, Noriko HATA, Issei KASAHARA, Katsumi GOT ...
    1995 Volume 44 Issue 4 Pages 307-309
    Published: April 05, 1995
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    It was found that a low concentration of organic solvent dissolved in the aqueous phase remarkably enhances the ion-pair extraction onto a solid-phase. The ion-pair distribution between solid and aqueous phases was studied in the presence of organic solvent dissolved in the aqueous phase. The magnitude of the extraction was expressed by the extraction constant (Kex) defined as: Kex=[C+·A-]s/{[C+][A-]} where C+ and A- denote the cation and anion studied, and the subscript s expresses the solid phase. Bis [2-(5-chloro-2-pyridylazo)-5-diethylaminophenolato]cobalt(III) ion and dodecanesulfonate ion were the cation and anion studied. A cellulose nitrate membrane filter and octadecyl modified silica gel (ODS) were studied as the solid phase. Dissolved organic solvents, nitrobenzene, o-xylene and benzene at 28×10-3 mol dm-3 in the aqueous phase, enhanced the distribution of the ion pair onto the solid-phases. In particular, in the case of ODS, o-xylene and nitrobenzene gave 2.5 and 2.2 greater log Kex values, respectively, compared with those in the absence of the solvents. The drastic enhancement of extracting power onto the solid-phase by the dissolved organic solvent will be useful for the improvement of collection efficiency in preconcentration for trace analysis.
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  • Chiyo MATSUBARA, Nobuyuki KIKUCHI, Kiyoko TAKAMURA
    1995 Volume 44 Issue 4 Pages 311-312
    Published: April 05, 1995
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    A preconcentration procedure using a thermally reversible polymer, poly(vinylmethylether) (PVME), is proposed for determining polycyclic aromatic hydrocarbons(PAHs) in air without using organic solvent. PVME is soluble in water below 31°C but solidifies abruptly on heating above 31°C becoming insoluble. Air sample was bubbled into 0.035% PVME aqueous solution below 31°C to dissolve the PAHs in air. With phase separation of PVME from the aqueous solution at 53°C, PAHs were captured in the resulting solid PVME which stuck to the wall of the reaction vessel. After discarding the supernatant solution by decantation, the PAHs were dissolved in a small volume of acetonitrile together with PVME. Each PAH was separated and quantified by HPLC with reversed phase column using fluorescence detection. The method was applied to 11 kinds of PAHs: the detection limit was 0.6pmol/test.
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  • Daisuke KURODA
    1995 Volume 44 Issue 4 Pages 313-318
    Published: April 05, 1995
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    Round robin tests were carried out by members of Association for Environmental Analysis in Osaka in order to determine the level of precision achievable for ion chromatography in the determination of hydrogen chloride, nitric oxide and sulfur dioxide in combustion gases. Although high precision was obtained on all analytes in this test, a lack of accuracy for the analytical values of nitric oxide and sulfur dioxide was recognized. In order to achieve good accuracy, it is necessary to check and eliminate all sources of systematic errors that can be detected in the laboratory.
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  • Kiyoshi NAKANE, Yoshinori UWAMINO, Hisashi MORIKAWA, Akira TSUGE, Yasu ...
    1995 Volume 44 Issue 4 Pages 319-324
    Published: April 05, 1995
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    Several decomposition methods were examined to determine impurities in sintered aluminium nitride and boron nitride samples. The pulverized samples were severely contaminated. A lump (about 0.3 g) of sintered aluminum nitride sample was decomposed with 15 ml of hydrochloric acid at 200°C, or 10 ml of sulfuric acid (1+2) at 230°C in a Teflon pressure vessel. Similarly sintered boron nitride samples were decomposed with a mixture of 7.5 ml of hydrofluoric acid and 2.5 ml of hydrochloric acid at 200°C. Several commercial samples were decomposed by the proposed methods, and impurities were determined by ICP-AES.
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  • Kenji KOBAYASHI
    1995 Volume 44 Issue 4 Pages 325-329
    Published: April 05, 1995
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    NAA was used to determine trace amounts of copper in the raw materials used for fabricating a fluoride optical fiber and its preform. Copper contamination remaining in the preform after fabrication was monitored during the whole preform fabrication process. Copper contamination from the experimental instruments was found to originate from a gold coated brass mold. It was also found that a high contamination of copper in the preform occurred within a thickness of 300μm from its surface.
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  • Masahisa TAKATSU
    1995 Volume 44 Issue 4 Pages 331-332
    Published: April 05, 1995
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
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