BUNSEKI KAGAKU
Print ISSN : 0525-1931
Volume 58, Issue 8
Displaying 1-20 of 20 articles from this issue
Research Papers
  • Ayako Nakata, Koichi Saito, Yusuke Iwasaki, Rie Ito, Reiko Kishi, Hiro ...
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 653-659
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    In this study, we focused our attention on breast fluid as specific perfluorinated compounds (PFCs) as an exposure source to infants, and developed a highly sensitive and accurate analytical method using high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS). For sample pretreatment, samples were determined using weak anion exchange (WAX) and solid phase extraction (SPE). The average recoveries of the analytes were in the range 94.3∼109.0% (RSD <10.3%), and the limits of quantitation (LOQ) were determined to be 0.012 ng/mL for PFOA and 0.004 ng/mL for PFOS, PFHxS and PFNA, respectively. Relatively high levels of PFCs were detected from human milk, which ranged over 0.046∼0.098 ng/mL for PFOS and over 0.016∼0.270 ng/mL for PFOA. In addition, human milk and maternal plasma collected from the same donor were analyzed. As a result, the concentration of PFCs in human milk and maternal plasma showed significant correlations for PFOS (r = 0.78) and PFOA (r = 0.82).
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  • Ayako Kohiyama, Masako Sato, Tsuyoshi Kaneko
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 661-665
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    Dispersive liquid-liquid microextraction (DLLME) coupled gas chromatography mass spectrometry was applied to the determination of benzodiazepines (flunitrazepam and nimetazepam). Some important parameters, such as the kind of extraction and the disperser solvent, the volume of the disperser solvent and the extraction time were investigated. Using the optimum conditions of DLLME for benzodiazepines, tricyclic antidepressant drugs (amitriptyline and nortriptyline) and phenothiazines (chlorpromazine and promethazine) were extracted from aqueous samples. In addition, the DLLME technique was applied to the extraction of flunitrazepam from alcohol drink ; simple and rapid extraction was possible. Thus, the DLLME technique is useful for the extraction of drugs in the forensic science field.
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  • Maiko Takeyama, Ryoei Kikuchi, Masanori Kumagai, Toshio Amano, Toru Oz ...
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 667-673
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    The water content of hair was measured by a dry-weight method, and was predicted by multiple-regression analysis using near-infrared (NIR) spectrum data after a spectra-pre-treatment. The correlation between the value by the dry-weight method and the NIR predicted value was r2 = 0.957, and indicated that predicting the water content of hair from the NIR spectrum data is possible. In addition, we obtained the formula ∂(lnw)/∂(1/T) = ΔH/R (w, water content ; ΔH, vaporization enthalpy change) by an analogy of the Clausius-Clapeyron equation, and we proposed that the individual variability of the moisture in hair (difficulty in evaporation of the water in the hair) is the difference in the vaporization enthalpy. The water content of the hair at 20∼100°C was measured for 10 people (21∼23 years old), and ΔH was obtained from the slope of plots of (ln [w/mol/kg]) vs. (1/T). As a result, the capacity of moisture in hair could be suggested by comparing it with ΔH (43.991 kJ/mol) of pure water.
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  • Chiho Ikeda, Ryosuke Nakahara, Yuka Nishioka, Hisashi Kurokawa, Takako ...
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 675-679
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    A spectrophotometric method for the determination of nitrite ion was established based on a fading of the pyrogallol red-molybdenum(VI) complex in the presence of sodium dodecylsulfate, an anionic surfactant. This method can be used to determine 40∼460 ng mL−1 nitrite ion ; the effective molar absorptivity at 535 nm and the relative standard deviation were 1.0 × 105 L mol−1 cm−1 and 1.92% (n = 6), respectively. This procedure is much more sensitive than that using a diazotization reaction. Recoveries of nitrite ion from real samples (rain water and commercial drinking water) were within 96.9∼100%.
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  • Aki Harada, Sayaka Ito, Kimiye Baba, Toshiki Koda, Tomoki Suizu, Mihoy ...
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 681-686
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    A new, simple and sensitive spectrophotometric method for the determination of Ti(IV) was established. The method was based on complex formation among 4-Hydroxyderricin (Hy) or Xanthoangelol (Xa) and Ti(IV) in the presence of anionic surfactant. {Hy} : Beer's law was obeyed in the range of 0.01∼0.96 μg/mL for Ti(IV) in a strong acidic medium. The effective molar absorptivity at 433 nm and 0.65% (n = 6). {Xa} : Beer's law was obeyed in the range of 0.02∼0.74 μg/mL for Ti(IV) in a strong acidic medium. The effective molar absorptivity at 429 nm and 0.53% (n = 6), respectively.
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  • Yusuke Hara, Tohru Saitoh, Hideaki Kasukabe, Masataka Hiraide
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 687-691
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    We found a selective fluorescence quenching of perylene by gold(III) in a micellar system of polyoxyethylene-type nonionic surfactants. Nitric acid was essential for incorporating gold(III) into the micelles, but deactivated the excitation of perylene. The deactivation was minimized by solubilizing perylene in micelles of nonionic surfactants having no aromatic moiety. Among the nonionic surfactants tested, Brij-35, having the shortest hydrocarbon chain and the highest polymerization degree of oxyethylene, was the best choice for obtaining the greatest quenching effect of gold(III). A linear relationship was obtained in the range of 5 × 10−8∼5 × 10−7 M of gold(III) in the presence of 1 M nitric acid and 0.05% (w/v) Brij-35. The Stern-Volmer quenching constant, Ksv, for gold(III) was 1.28 × 107 M−1. On the other hand, the Ksv (M−1) values were 4.3 × 104 for platinum(II), 8 × 103 for palladium(II), and 5 × 102 for iron(III), being far smaller than the value for gold(III). Other metal ions including aluminum(III), manganese(II), cobalt(II), nickel(II), copper(II), zinc(II), silver(I), tin(IV), and lead(II) at 10−4 M had negligible quenching effect. The present method can be applicable to the selective determination of traces of gold(III).
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  • Tetsuya Akutsu, Tokuo Shimizu, Nobuo Uehara
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 693-698
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    A simple and selective method for the speciation of sub μg/L levels of inorganic chromium species in water sample is described. The proposed method is based on micro solvent extraction with an in situ extractant formation method and graphite furnace atomic absorption spectrometry. By mixing carbon disulfide and pyrrolidine in xylene prior to use, pyrrolidinedithiocarbamic (PDC) acid forms. The extraction behavior of Cr(III) and Cr(VI) caused by a variation of the pH and composition of a mixed solvent was investigated. At pH 3.0, Cr(VI) was selectively extracted from co-existing Cr(III) as a PDC complex. At pH 6.0, both Cr(III) and Cr(VI) were simultaneously extracted into the organic phase after heating at 35°C for 30 min. A 20 μL aliquot of the organic phase was injected into a graphite furnace. Under a 50-fold preconcentration factor by using 25 mL of water samples, linear calibration curves of Cr(VI) and total Cr [Cr(III)] were obtained over the range of 0 to 0.4 μg/L and 0 to 0.5 μg/L with detection limits (3σ) of 0.75 ng/L and 0.64 ng/L. The relative standard deviations (n = 10) were 1.8% and 3.4% for 0.16 μg/L of Cr(VI) and Cr(III), respectively. The proposed method was successfully applied to mineral water, river water and spiked samples.
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  • Hua Jin, Akhmad Sabarudin, Mitsuko Oshima, Shoji Motomizu
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 699-706
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    A collection/concentration system controlled automatically by a lab-made program incorporated in ICP-AES was used to determine multi-elements in green tea leaves and their extracts into hot water. Twenty four elements (Cd, Ce, Co, Cu, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Ni, Pb, Pr, Sc, Sm, Tb, Th, Tm, V, Y, Tb and Zn) could be collected on a ME-3 chelating resin packed in a mini-column. This mini-column was installed in the selection valve on the collection/concentration system, which was connected on line to ICP-AES. Conditioning of the resin was carried out with a 1 mL portion of a 0.5 M ammonium acetate buffer solution (pH 5.5) at a flowing rate of 50 μL min−1, collecting elements with 10 mL of the sample solution (pH 5.5) at a flowing rate of 70 μL min−1, and washing with 0.5 mL of water. Elution was done by passing through 2.5 mL of 2 M HNO3 at 35 μL min−1. The enrichment factors of elements were from 40 to 74, and the detection limits (LOD) were from 0.01 ppb to 0.20 ppb. The RSDs of 7 measurements with 0.5 ng mL−1 standard solution were between 2.9 and 8.9%. Tea leaves were digested by a microwave without hydrofluoric acid after predigesting and the digested solutions were measured directly by ICP-AES. The extracts from tea leaves in hot water could be measured with the proposed collection/concentration system.
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  • Teruo Arakaki, Teruyuki Ishigaki, Mami Yamaguchi, Akihide Itoh
    Article type: Research Papers
    2009 Volume 58 Issue 8 Pages 707-714
    Published: 2009
    Released on J-STAGE: October 09, 2009
    JOURNAL FREE ACCESS
    The dissolved and acid-soluble concentrations of major and trace elements in deep and surface seawater samples near Kume Island in Okinawa Prefecture were investigated by ICP-MS and ICP-AES with two types of preconcentration methods using chelating disk preconcentration and lanthanum hydroxide coprecipitation. As a result, 16 elements in each sample were determined over the concentration range from% to ng L−1 (ppt). In addition, it was elucidated from multielement profiling analyses by using the obtained analytical results that the concentrations of Cd, Zn, Ni, Cu, and Co in deep seawater near Kume Island were higher than those at the surface. The acid-soluble particle fraction to the total concentration (Pacid) was calculated from dissolved and acid-soluble concentrations. The Pacid values for Cu, Co, Zn, and Ni in deep seawater were 10∼30%, and higher than those at the surface, while that for Cd was below 10%, and almost the same as those for the surface. The results suggested that portions of Cu, Co, Zn, and Ni exist as acid-soluble biogenic particles in deep seawater (water depth : 612 m), which were detritus and colloidal particles bound with organic matter, while most Cd exists as a dissolved form.
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