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Volume 55, Issue 10
Displaying 1-9 of 9 articles from this issue
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Research Paper
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Teruhiko KASHIWABARA, Akiko HOKURA, Nobuyuki KITAJIMA, Ryoko ONUMA, Hi ...2006 Volume 55 Issue 10 Pages 743-748
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSPteris vittata L. has come into use as a technology of phytoremediation due to its hyperaccumulation ability of As. The distributions of arsenic and potassium in roots were examined by synchrotron radiation (SR)-XRF imaging; and the valence change from the top to the base of roots was revealed for the first time by As K-edge XANES. Freeze-drying technique was adopted as an effective preparation method for the handling of roots. The vertical beam size was set to 300 μm by a spherical focusing mirror and the horizontal beam size was adjusted to 2800 μm by the slits. By adopting this wide X-ray beam, the elemental distribution along the roots can be appropriately evaluated despite their winding shapes. It was found that the concentration of arsenic became higher from the top to the base of the roots, while that of potassium remained almost constant. Furthermore, the oxidation state of arsenic at the top of the roots was dominantly As(III), while that at the base was As(V).
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Kenji KODAMA, Kazuaki WAGATSUMA2006 Volume 55 Issue 10 Pages 749-755
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSA new three-electrode hollow cathode glow discharge lamp and a measuring technique were developed so that the sputtering process and emission process can be separated individually. The modulation technique was applied to the processes for creating a hollow cathode plasma as well as sputtering a sample. To detect specific emission lines of sample atoms from the overall signals, we used a Fast Fourier Transfer (FFT) spectrum analyzer. We could determine the bias voltages under the optimum discharge conditions for measuring the emission signal of the sample selectively by reading the component of the sputtering frequency in the FFT power spectrum. A three-electrode hollow cathode glow discharge lamp with an FFT spectrum analyzer is a promising analytical method for microanalysis.
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Takashi YOKOYAMA, Keiko MURATA, Sakiko MUKAI, Keisuke UOMOTO, Toshihir ...2006 Volume 55 Issue 10 Pages 757-763
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSPre-concentration methods of aluminum for flame atomic absorption spectrophotometry (FAAS) by solvent extraction and solid-phase extraction using 8-quinolinol (8-HQ) derivatives as a chelating reagent were investigated, where an organic solvent extracted or dissolved the aluminum with the chelating reagent was directly introduced into FAAS. In the case of the solid-phase extraction of aluminum with 0.29 g of a powdered solid of 8-HQ using 100 ml of sample water in the presence of 0.1 mol dm−3 sodium carbonate buffer at pH 9.0 for 90 min stirring, the highest apparent enrichment factor of the aluminum ion was 28, when the powdered solid 8-HQ extracted the aluminum was dissolved in 1 ml of nitrobenzene (NB). In the case of solvent extraction, the highest pre-concentration of the aluminum by the solvent extraction of 1000 ml of the sample water in the presence of 0.1 mol dm−3 sodium carbonate buffer at pH 9.0 with 2 mol dm−3 8-HQ in 3 ml NB for 70 min stirring was achieved. The enrichment factor and the detection limit (3 σ) of the aluminum were 514 and 2.7 ng ml−1, respectively. The relative standard deviation for FAAS signals in this method was 8.5% (n = 8) for 10 ng ml−1 aluminum. The high pre-concentration method of solvent extraction was applied to the determination of aluminum in river water and tap water, resulting in 10.9, 4.5, and 9.5 ng ml−1 for tap water and two river-water samples, respectively.
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Yasuhiro GOU2006 Volume 55 Issue 10 Pages 765-771
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSA spectrophotometric method for the determination of nitrate-nitrogen was developed based on the reaction of nitrate with 1-naphthol-8-sulfonic acid in the presence of sulfuric acid and chloride. A calibration curve based on the absorbance at 350 nm against a reagent-blank reference was linear in the concentration range of 0∼6.00 μg/ml of nitrate-nitrogen. The color development can probably be ascribed to the formation of a nitroso-derivative of the parent acid caused by nitrosyl chloride resulting from the reaction of nitrate and chloride under strongly acidic conditions. The interference of common inorganic anions and cations was not serious, expect for nitrite, which gave a high positive error. This method was able to measure nitrate-nitrogen in well water and river water. The results were in good agreement with those obtained by an ion chromatographic method. In addition, this method gave satisfactory results in the determination of total nitrogen in sewage water, and was also useful for a semi-quantitative analysis of nitrate based on the strength of the developed color.
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Technical Paper
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Takakazu HANZAWA, Kunio NAGASHIMA, Minori KAMAYA, Gaku ISHIGURO, Nobuo ...2006 Volume 55 Issue 10 Pages 773-779
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSA sample solution was pumped at a flow rate of 3 ml min−1 to a transparent PTFE tube (3 × 2 mm, 170 cm length), which was wound around an UV lump (rod shape, 17 mmφ, 145 mm length, λ = 254 nm, 4 W). A metal cyano complex {potassium hexacyanoferrate(III) (0∼0.2 mgCN dm−3)} was converted to CN− by UV (254 nm) irradiation of a sample solution at an efficiency of 100% (1 mol to 6 mol of CN−). Zn(II) and Cu(II)cyano complexes were successfully converted to CN− by the UV irradiation. The CN− produced was determined as follows. The sample solution was pumped to the mixing joint, where sulfuric acid (0.05 M) was mixed at a rate of 2 ml min−1. A mixture containing hydrogen cyanide was fed into a gas-liquid separation tube (pore size, 1 μ; microporous Teflon tube of 2 mm i.d., 3 mm o.d., 900 mm length). Hydrogen cyanide that evolved from the gas-liquid separation tube was purged by purified air (700 ml min−1) onto HCN monitoring tape. The efficiency {CN−→HCN(gas)} obtained by using the gas liquid separator was about 3%. When the monitoring tape was exposed to HCN gas, the tape became homogeneously colored. The degree of color intensity was proportional to the concentration of CN− in the sample solution. The relative standard deviation of the response to 0.1 mgCN− dm−3 was 2.1%. The method has detection limits of 0.02 mgCN dm−3 with a sampling time of 5 minutes. Standard addition method showed that this method could detect cyanide in a treated waste liquid of a chemical laboratory.
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Kunihiro WATANABE, Miyuki TOJO, Masayuki ITAGAKI2006 Volume 55 Issue 10 Pages 781-786
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSThe flow injection analysis of a trace amount of chromium ion was investigated by an on-line concentration method using a Teflon filter tube. 1,5-Diphenylcarbazide was used as a detection reagent for the spectrophotometric determination of Cr(VI). Cr(VI) was coprecipitated with aluminum hydroxide in a reaction coil at pH 8.0∼8.5; then, the coprecipitate of Cr(VI) and Al(III) was collected with a filter tube by concentration for 5 min at a sample flow rate of 2 ml/min. The precipitate collected was eluted with 1 M HNO3 as a carrier solution. The Cr(VI) was determined on-line by monitoring at 542 nm. When Al(III) was used as a precipitant, the limit of detection and the lower limit of determination for Cr(VI) were 0.08 and 0.25 ppb, respectively. The relative standard deviation (RSD) for 30 ppb Cr(VI) was 0.3% (n = 7). On the other hand, Pb(II) was used as a precipitant; then, a calibration curve constructed by 60 min concentration for Cr(VI) was linear over the range 0 to 50 ppb. The limits of detection and determination for chromium were 0.004 and 0.013 ppb, respectively. The RSD for 2 ppb Cr(VI) was 1.0% (n = 7). The proposed method was applied to the determination of river water samples. As a result, the chromium in the natural water samples examined was below the detection limit (0.004 ppb). The proposed FIA system could afford a simple and rapid analysis of Cr(VI) in natural water samples.
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Note
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Asako AKIYAMA, Kaori IMAI, Sachiko ISHIDA, Kenji ITO, Tadashi KOBAYASH ...2006 Volume 55 Issue 10 Pages 787-792
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSAn analytical method for the determination of aromatic compounds exhalated from hand skin has been proposed. The sampling of exhalated aromatic compounds was performed as follows: after the intake of aromatic compounds included in chewing gum or a capsule, exhalated skin gas was collected from a hand. The hand was covered with a sampling bag of poly vinyl fluoride (PVF) for 30 min. Then, the inner space of the sampling bag was sprayed with a 25% of ethanol aqueous solution. After removing the hand from the bag, the trapped solution containing skin gas was collected. The aromatic compounds in the trapped solution were extracted to the solid phase as Twister® (stir bar coated with poly dimethyl siloxane, Gerstel). Extracts were determined by gas-chromatograph mass spectrometry using a thermo desorption system and a selective ion mode. Linalool, citronellol and geraniol, which are the main components of rose essential oil, were detected from the skin of a hand after an oral intake of rose oil. The exhalated absolute amount of linalool, citronellol and geraniol increased in 30 to 60 min, and then decreased after intake. The recoveries of linalool, citronellol and geraniol were 53.5%, 66.7% and 55.1%, respectively. The correlation coefficient of the standard curves for linalool, citronellol and geraniol were 0.9977, 0.9994 and 0.9987, respectively. Each compound exahalated from the skin of a human body during 6 hours after intake was estimated to be, according to the amount of intake, 0.39%, 0.09% and 0.25%, respectively, for one subject. The absolute amount of geraniol exhalated from a hand increased significantly after oral intake for 8 subjects (P<0.025). This is the first report to present hard proof that an aromatic compound was exhalated from human skin after its intake as food.
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Seiichiro IOKA, Teruki IWATSUKI, Osamu KATO, Tsuyoshi IMAKITA2006 Volume 55 Issue 10 Pages 793-797
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSA performance test for a redox potential measurement of a solution was conducted using continuously polished and untreated platinum working electrodes under an inert condition. The redox potential, measured by a polished electrode, immediately showed steady value which approximately coincided with the equilibrium value of redox reaction between HS− and S42−. Thus, the redox potentials could be controlled by the equilibrium of the redox reaction. On the other hand, the redox potential measured by an untreated electrode was +0.2 V higher than that measured by a continuously polished electrode. The measured redox potential implies that SO42− was the dominant species in the solution. A disagreement of the redox potentials measured by polished and untreated electrodes may have been caused by deactivation of the platinum electrode by the adsorption of sulfuric acid anions.
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Analytical Report
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Kazuhiko NAKANO, Toshihiro NAKAMURA, Izumi NAKAI, Akira KAWASE, Makoto ...2006 Volume 55 Issue 10 Pages 799-806
Published: 2006
Released on J-STAGE: November 17, 2006
JOURNAL FREE ACCESSThe Japan Society for Analytical Chemistry has developed new plastic certified reference materials (CRMs) for the analysis of four hazardous elements (Pb, Cd Cr and Hg) in plastics to ensure the quality control of analyses. These CRMs (named as JSAC 0601-1 and 0602-1) were prepared by leading a raw material liquid of polyester resin mixed with hardener and organometallic compounds into a flat mold. The obtained plastics plates were crushed in a chip form by a mill, and sieved to obtain 0.5∼1 mm size pieces. An interlaboratory comparison study was performed with the participation of 20 laboratories. z-scores of the robust method were applied for a statistical analysis. The certified uncertainties were determined at the confidence levels of 95%. These presented CRMs are the first reference materials for plastics in Japan for the analysis of hazardous metals contained in plastics, and are expected to be useful for the quality assurance and quality control of trace metals in plastics.
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