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Volume 54, Issue 5
Displaying 1-9 of 9 articles from this issue
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Shoji ISHIZAKA, Yuichi UEDA, Yoshiaki NISHIJIMA, Noboru KITAMURA2005 Volume 54 Issue 5 Pages 339-346
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSMolecular interactions proceeding at a water/CCl4 interface were investigated directly by means of time-resolved total-internal-reflection (TIR) fluorescence spectroscopy. The TIR fluorescence decay profiles and fluorescence dynamic anisotropy decays of Riboflavin (RF) in the presence or absence of a N,N -dioctadecyl-[1,3,5]triazine-2,4,6-triamine (DTT) as a guest in the CCl4 phase indicated that molecular recognition mediated by complementary triple hydrogen bonding took place effectively at the water/CCl4 interface. Furthermore, the photoreaction mechanisms of the RF-DTT hydrogen-bonded complex that proceeded at the water/CCl4 interface were considered based on results observed by steady state and dynamic fluorescence measurements of the RF-DTT complex under the TIR conditions. Hybridization of complementary single-stranded DNAs at a water/CCl4 interface was also studied by the fluorescence dynamics of ethidium bromide as a probe for the DNA structure. The structures of double-stranded DNA at the interface were analyzed.
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Research Paper
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Takafumi HIRATA, Ichitaro KOHGE2005 Volume 54 Issue 5 Pages 347-354
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSA new desolvating sample introduction system has been developed for precise isotopic ratio measurements of 56Fe/54Fe using a multiple collector-inductively coupled plasma-mass spectrometry (MC-ICPMS). The production of 56ArO+ ions could be significantly reduced by a removal of water vapour using a membrane filter. Sample aerosol was directly heated up by a rod-heater through glass tubing, aiming at a higher separation efficiency of the water vapour from sample aerosol. This direct-heating technique could minimize the length of the membrane filter for desolvation down to the 300 ~ 350 mm level, which was almost order of magnitude shorter than that of conventional desolvating system using the membrane filter. The shorter membrane filter results in smaller memory effect as well as shorter washout time of the signal down to 2 ~ 3 minutes, which was at the 1/3 ~ 1/5 level compared with the conventional desolvating system. This is a very pleasing result because we can take full advantage of the rapidness of the analysis achieved by the ICP-MS technique, even with the desolvating sample-introduction system. The resulting instrumental sensitivity achieved here was identical to that obtained by the conventional solution nebulisation (2 V/μg g−1), indicative of no significant loss of analytes during the desolvating stage. In order to evaluate the analytical capability of the present sample introduction technique, the 56Fe/54Fe isotopic ratio for an Fe isotopic standard reference material (IRMM-014 SRM) was measured. The precision in the 56Fe/54Fe ratio measurements achieved from 2 μg of Fe was 0.04% (2SD, n = 60 × 5 runs), which was significantly smaller than the isotopic variation in the 56Fe/54Fe ratio typically found in nature.
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Hiroshi UCHIHARA, Masahiko IKEDA, Taketoshi NAKAHARA2005 Volume 54 Issue 5 Pages 355-360
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSA new sample introducing method to ICP-AES is described for the determination of zinc. The impulse graphite furnace of an inert gas fusion was used to generate of halide vapor (HVG). A 10 μl sample solution of 0.1 mg Zn/ml with 50 mg/ml of ammonium chloride was dropped into a graphite crucible, vaporized as zinc chloride, and heated for 5 seconds at 2000°C after drying within 120 second at 100°C. The emission intensity at 213.86 nm of zinc was integrated every 0.2 seconds. The emission intensity of 1 μg of zinc as nitrate and sulfate added ammonium chloride, increased by about 100 times. The relative standard deviation in this study was 1.4 ~ 4.3% (n = 6), and the limit of detection was 60 pg (3 σ of the blank value). This method was successfully applied to the analysis of an environmental standard reference material (NIES No. 8).
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Yuichi HORII, Gert PETRICK, Makoto OKADA, Kazuo AMANO, Takao KATASE, T ...2005 Volume 54 Issue 5 Pages 361-372
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSIn this study, we developed a new approach of compound-specific carbon isotopic analysis using a two-dimensional gas chromatograph (2DGC) with a combustion furnace (C) isotope ratio mass spectrometer (IRMS), and applied it for the “congener-specific” carbon isotopic analysis of polychlorinated biphenyls (PCBs). It was clarified that the 2DGC system enables a better separation of individual PCB congeners than a single column. Accurate values of δ13C were obtained for some congeners without co-elution. At the same time, a decrease of an undesirable organic carbon source from an impurity in the sample and column breed into the second column separation resulted in a significant improvement of detection limit. The estimated sensitivity of carbon using 2DGC/C/IRMS was less than 7 ng. Totally, thirty-one PCB congeners were measured in 18 PCB products: Kanechlors, Aroclors, Clophens, Phenoclors, Sovol, Trichlorodiphenyl including two PCB products from Eastern Europe (Delors, Chlorofen). Observed δ13C values of individual PCB congeners from 2DGC/C/IRMS ranged from −34.4 (CB180, Delor106) to −22.0‰ (CB70/76, Sovol). These values are comparable to δ13C value expected for industrial chemicals made of shell oil. However, we found a specific trend of a decrease in the isotope compositions according to increasing chlorine number in each PCB product. Increased chlorine number caused increased 13C depletion in all PCBs. It is worth mentioning that Delors and Chlorofen had a completly different range of δ13C values for other PCB products, and could be identified by isotopic compositions. The wide range of isotopic compositions between the PCB products and individual congeners may prove to be a powerful tool in the determining the source of PCBs in the environment. This technique may have wide applications in environmental chemistry.
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Jun HORIGOME, Naoki FURUTA2005 Volume 54 Issue 5 Pages 373-380
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSAn inductively coupled plasma mass spectrometer with an ion-trap mass spectrometer was used for the determination of Fe and Se in biological samples. The spectral interferences of Ar2+, 31P216O+, 12C35Cl2+ and 32S16O3+ on 78Se+, 80Se+ and 82Se+ were eliminated by optimizing the ion level and FNF (filtered noise field) function of 3DQMS (three dimensional quadrupole mass spectrometer). As a result of decreasing 40Ar2+, a linearity of 7 orders of magnitude from 100 ppt to 100 ppm and a limit of detection of 11 ppt were achieved at 80Se. The spectral interferences of 40Ar16O+, 40Ca16O+, 79Br1H+ and 81Br1H+ decreased by using the CID (collision induced dissociation) function of 3DQMS. The optimum conditions of CID obtained from the signal intensity and the isotopic ratio of Fe and Se were 0 V and 500 ms. Under the optimum conditions of the ion level, FNF and CID, Se in human urine standard materials (NIES CRM 18 and Seronorm 2524) was determined; the analytical results showed good agreement with reference values within the analytical error, and a recovery of 101% could be attained for Fe in human urine standard material (Seronorm 2524). The developed method enabled us to determine Se and Fe in biological samples by using the most abundant isotopes of 56Fe and 80Se.
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Technical Paper
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Kenji SATO, Hiromi TAN-NO, Jyunya SATO, Shigeyuki TANAKA2005 Volume 54 Issue 5 Pages 381-385
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSA rapid and simple method for determining fat acidity in rice bran based on Fourier-transform infrared (FT-IR) spectrometry is described. Fat acidity is utilized as one possible deterioration indicator for changes of rice qualities during storage. The extraction of free fatty acids in rice bran was carried out using carbon tetrachloride as an organic solvent. A carbon tetrachloride solution containing free fatty acids in 1.0 mm KBr cell was measured by FT-IR spectrometry. The rice bran sample was stored at 30°C with 55 ~ 65% humidity. The absorbance of the C=O stretching vibration band at 1710 cm−1 for free fatty acids in the FT-IR spectra increases linearly with storage periods of from 0 to 55 days. However, the absorbance of the C=O stretching vibration band at 1745 cm−1 for ester decreased. Fat acidities obtained by the present method showed a good correlation with an acid-based titration method (r = 0.997). The relative standard deviation (RSD, n = 6) of the measured fat acidity was less than 9%. The present method proved to be simple and rapid, and allowed measurements with small amounts of the sample and the extracting solvent compared with the previously acid-based titration method.
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Note
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Kousaburou OHASHI, Tomohiro HADA, Akira OHASHI, Hisanori IMURA2005 Volume 54 Issue 5 Pages 387-390
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSHumic acid (HA) from Wako (WHA) was characterized by FT-IR, the pH titration method, and the electric conductivity method. WHA has carboxylate, carbonyl, phenol-OH and hydroxy-OH groups, which are responsible for complex formation with metals. The capacity of the acidic functional groups of WHA was determined to be 1.54 meq g−1. The binding capacity for chromium(III) of WHA was determined by ICP-AES to be 2.2 mmol g−1. The procedure for the direct determination of chromium(III) in the precipitated chromium(III)-WHA complex was investigated by energy dispersive X-ray fluorescence spectrometry (EDXRF). The calibration curve showed a good linear relationship in the range of 0.2 ~ 5.3 mmol chromium(III) bound to WHA.
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Yuko KATO, Masaya OHTA, Kyouhei KAMEI, Hisanobu WAKITA, Takeshi KAWAHA ...2005 Volume 54 Issue 5 Pages 391-397
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSMineral water, named Catalyser 21, prepared by the fermentation of ancient natural leaf soil, is often used as health-beneficial drinking water to enhance the immune system of cancer patients. The mineral water was dialyzed and fractionated by using gel chromatography. Fraction 4, containing carbohydrates, was further purified by using negative ion chromatography, obtaining a fraction named Fr4 (1-2). The Fr4 (1-2) was analyzed using the ABME marker method, carbohydrate analysis. It was composed of nine carbohydrates. The NMR spectra showed some specific complex carbohydrates pattern in the 1H-NMR and 2D-NMR HMQC methods. There were many cross peaks in the HMQC spectra, which displayed 13C-1H relationships of the anomeric region of complex carbohydrates Macrophages secrete interleukin-12 (IL-12), which activate the tumor immune system. The induction activity of the Fr4 (1-2) for IL-12 on the murine macrophage cell line, RAW264.7, was tested using the RT-PCR method. The Fr4 (1-2) induced the gene expression of IL-12, suggesting that polysaccharides in mineral water are responsible for the IL-12 induction activity.
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Short Communication
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Use of Two Different Serial Power Pulses for a Light Absorption Measurement at Low Gas ConcentrationYuji KATO, Takao TSUDA, Tadayoshi YOSHIDA2005 Volume 54 Issue 5 Pages 399-402
Published: 2005
Released on J-STAGE: August 31, 2005
JOURNAL FREE ACCESSWe propose a measuring method for low-concentration gas using two different power pulses for deducing of the noise level derived from spectroscopic systems including a light-emitting diode (LED) and an amplifier. After two-different pulse currents were applied to a LED, and the pulsed light beams emitted by the LED were passed through to a long-path gas cell with a multi-reflectional mirror, (path length, 105 cm). The pulse was divided into reference and sample beams. Each reference beam (I01, I02) and sample beam (I1, I2) obtained from two different power pulses were subtracted as (I01-I02) and (I1-I2), respectively. By using these two values, the sample concentration was estimated by using the Lambert-Beer law. Acetone gas was used as a test sample gas. Acetone gases of 0 ~ 90, 60 ~ 900 ppm concentration were measured with the present method. By calculating these signals differece, the electric noise in this apparatus was canceled, and we could measure low-concentration gas. The proposed method gave good calibration curves.
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