Vol. 54 No. 5
May, 2005
Shoji Ishizaka1, Yuichi Ueda1, Yoshiaki Nishijima1 and Noboru Kitamura1
1 Division of Chemistry, Graduate School of Science, Hokkaido University, Kita 10-Nishi 8, Kita-ku, Sapporo-shi, Hokkaido 060-0810(Received 7 February 2005, Accepted 30 March 2005)
Molecular 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.
Keywords : liquid-liquid interface; molecular recognition; total internal reflection fluorometry.
Takafumi Hirata1 and Ichitaro Kohge1,2
1 Laboratory for Planetary Sciences, Tokyo Institute of Technology, O-okayama 2-12-1, Meguro-ku, Tokyo 152-8551(Received 12 November 2004, Accepted 3 February 2005)
A 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 µm 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/mg 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.
Keywords : desolvating system; membrane filter; Fe isotopic analysis; multiple collector; ICP-mass spectrometer.
Hiroshi Uchihara1, Masahiko Ikeda1 and Taketoshi Nakahara2
1 HORIBA Application Center, 2, Miyanohigashi, Kisshoin, Minami-ku, Kyoto-shi, Kyoto 601-8510(Received 13 August 2004, Accepted 7 February 2005)
A 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 µg 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 (3σ of the blank value). This method was successfully applied to the analysis of an environmental standard reference material (NIES No. 8).
Keywords : zinc; ammonium chloride; halide vapor generation; graphite furnace ICP-AES; chlorine compound; vehicle exhaust particulates.
Yuichi Horii1,2, Gert Petrick3, Makoto Okada2, Kazuo Amano2, Takao Katase4, Toshitaka Gamo5 and Nobuyoshi Yamashita1
1 Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), 16-1, Onogawa, Tsukuba-shi, Ibaraki 305-8569(Received 30 November 2004, Accepted 21 February 2005)
In 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 d13C 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 d13C 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 d13C 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 d13C 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.
Keywords : carbon isotope; PCB; two dimensional GC; CSIA; IRMS.
Jun Horigome1 and Naoki Furuta1
1 Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551(Received 25 November 2004, Accepted 1 March 2005)
An 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.
Keywords : inductively coupled plasma; ion-trap mass spectrometer; spectral interferences; biological samples; ICP-3DQMS.
Kenji Sato1, Hiromi Tan-no1, Jyunya Sato1 and Shigeyuki Tanaka1
1 Department of Life and Environmental Science, College of Science and Engineering, Iwaki Meisei University, 5-5-1, Iino, Chuodai, Iwaki-shi, Fukushima 970-8551(Received 1 November 2004, Accepted 30 March 2005)
A 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.
Keywords : FT-IR spectrometry; fat acidity; rice bran; free fatty acid; rice quality.
Kousaburou Ohashi1, Tomohiro Hada1, Akira Ohashi1 and Hisanori Imura1
1 Department of Environmental Sciences, Faculty of Science, Ibaraki University, 2-1-1, Bunkyo, Mito-shi, Ibaraki 310-8512(Received 3 December 2004, Accepted 21 February 2005)
Humic 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.
Keywords : humic acid; chromium(III); energy dispersive X-ray fluorescence spectrometry.
Yuko Kato1,3, Masaya Ohta2, Kyouhei Kamei1, Hisanobu Wakita3, Takeshi Kawahara4, Yuuichiro Yamano4, Takeki Hamasaki4, Kiichiro Teruya4, Kazuhiro Osada4, Ryuhei Nishikawa4, Katsumi Noguchi5 and Sanetaka Shirahata4
1 Department of Industrial Chemistry, Faculty of Engineering, Tohwa University, 1-1-1, Chikushigaoka, Minami-ku, Fukuoka-shi, Fukuoka 815-8510(Received 11 January 2005, Accepted 25 March 2005)
Mineral 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.
Keywords : anti-tumor activity; structure analysis; complex carbohydrate; NMR; HMQC; Interleukin-12.
Yuji Kato1, Takao Tsuda2 and Tadayoshi Yoshida1
1 Department of Material Science and Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya-shi, Aichi 466-8555(Received 15 February 2005, Accepted 24 March 2005)
We 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.
Keywords : two-different pulse; Lambert-Beer law; low concentration gas; spectroscopy.
Yoshinori Sekiguchi
Department of Applied Chemistry, Faculty of Engineering, Kanagawa Institute of Technology, 1030, Shimo-ogino, Atsugi-shi, Kanagawa
(Awarded by Kanagawa Institute of Technology dated March 25, 2004)
A thermostable histamine oxidase was found in cell extracts of Arthrobacter crystallopoietes KAIT-B-007 isolated from soil. The purified enzyme was homogeneous on Native-PAGE and SDS-PAGE. As a result of SDS-PAGE, the enzyme was shown to be a single protein with a molecular mass of about 81 kDa without subunit structure. The enzyme showed powerful activity toward histamine (100%) and had little activity toward tyramine (36%). The enzyme was show keep its activity of about 70% after heating at 70°C for 60 min. On the other hand, the enzyme from A. globiformis IFO12137 was fully lost its activity upon heating at 70°C for 30 min. The histamine oxidase from A. crystallopoietes KAIT-B-007 was very thermostable. The enzyme is copper/2,4,5-trihydroxyphenylalanyl quinone -containing protein having one atom of copper and one molecule of TPQ per one molecule of the enzyme protein. The enzyme gene was cloned, and its complete DNA was sequenced. The histamine oxidase gene consisted of an open reading frame of 2,172-bp encoding a protein of 725 amino acids. The deduced amino acid sequence of this enzyme was 84%, similar to that of histamine oxidase from A. globiformis IFO12137. A chemiluminometric flow-through sensor for the determination of histamine was prepared on the basis of co-immobilized histamine oxidase and peroxidase. The calibration curve for histamine was linear from 0.1 to 50 mM. The present method gave good agreement with values obtained by HPLC, and the calculated coefficient of correlation was 0.996. This sensor system was applicable to the determination of histamine in fish meat extracts.
(Received December 27, 2004)
Keywords : histamine; histamine oxidase.
Yoshio Moriya
Department of Materials-process Engineering and Applied Chemistry for Environments, Faculty of Engineering and Resource Science, Akita University, 1-1, Tegata Gakuencho, Akita-shi, Akita 010-8502
(Awarded by Akita University dated March 31, 2004)
Interfacial adsorption-precipitation phenomena in the solvent extraction systems were investigated for developing a no-precipitation process in hydrometallurgy, and a direct spectroscopic approach for interfacial adsorbates. This paper first addresses the metal-carboxylate extraction system, which typically shows these phenomena. A selection guide for a no-precipitation process was proposed based on the interfacial reaction mechanism. Next, the utility of partial reflection spectrometry was investigated using a J-aggregate of protonated tetraphenylporphyrin adsorbed at the inert organic solvent-aqueous sulfuric acid interface and some home-made optical devices. External reflection (ER) spectrometry was effective to distinguish interfacial Gibbs adsorbates from lipophilic solutes in the organic phase, and to discriminate the adsorption-state change from monolayer to multilayer. The saturated interfacial density of protonated species in the dodecane-4 M H2SO4 system was 1.2×10-10 mol cm-2, which yielded a tilt angle of 47°of the pyrrole ring plane from the interface normal. Positive and negative bands were observed in the p-polarized spectra of ER (p-ER) and partial internal reflection (p-PIR) with the same band location, but with reversed sign to each other. These results suggest that the surface selection rule of p-PIR spectrometry has a reversal rule of p-ER, and PIR can also be used to analyze the molecular orientation.
(Received February 2, 2005)
Keywords : interfacial adsorbate; metal-carboxylates; tetraphenylporphyrin; external reflection; partial internal reflection; surface selection rule.
Masaki Ono
Analytical Laboratory, Taisho Pharmaceutical CO., LTD. 1-403, Yoshino-cho,
(Awarded by Niigata University of Pharmacy & Applied Life Sciences dated March 18, 2004)
Automated detection systems using immobilized enzyme reactors for the determination of riboflavin phosphate (FMNs) and myo- inositol (MI) in a multivitamin pharmaceutical preparation were constructed. A high-performance liquid chromatographic detection system using a pre-column enzyme reactor, in which immobilized sweet potato acid phosphatase was packed, was developed for the simultaneous determination of FMNs and other water-soluble vitamins. Enzymatically hydrolyzed riboflavin and other ingredients in the pharmaceutical preparation were concentrated in an ODS trap column. The concentrated riboflavin and other ingredients were back-eluted from the trap column, and the chromatographed on an ODS analytical column. The effluents were monitored by UV absorption at 280 nm. An automated flow-injection system using an enzyme reactor, in which immobilized myo-inositol dehydrogenase was packed, was developed for the specific determination of MI. MI was detected using a fluorophotometer, to measure the fluorescence of NADH produced from NAD+ by the reactor. Enhanced interference due to excess glucose included in a pharmaceutical preparation as a sweetener was eliminated by a glucose eliminating reactor co-immobilized with three enzymes (glucose oxidase, mutarotase and catalase). The two automated detection system for the determination of ingredients in pharmaceutical preparations was superior to ordinary manual methods in terms of being harmless to the environment, rapidity and accuracy under continuous autoanalysis.
(Received January 28, 2005)
Keywords : riboflavin phosphate; immobilized enzyme reactor; automation; acid phosphatase; myo-inositol; flow injection analysis; myo-inositol dehydrogenase; HPLC.
Masanori Kumagai
Akita Research Institute of Food and Brewing, 4-26, Sanuki, Araya-machi, Akita-shi, Akita 010-1623
(Awarded by Akita University dated March 23, 2004)
Near infrared (NIR) spectroscopy uses the radiation wave region between 700 and 2500 nm. NIR spectroscopy has recently been developed and used as a rapid, nondestructive and convenient technique for the qualitative and quantitative compositional analysis of many kinds of materials. Although the practical applications of NIR spectroscopy for numerous industrial purpose are extensive, it is desired to build up the spectral analysis methods based on the chemical basis. In addition, the development of a low-cost and downsized instrument may be expected to tremendously expand the application of NIRS. In this study, I have attempted to distinguish some plastics and foodstuffs using a portable NIRS instrument that relies not only on a statistical and mathematical approach, but also on a chemical interpretation of the NIR spectra. The strategy was to propose a qualitative discrimination and a quantitative analysis of materials coupled with chemical information based on their compositional differences. NIRS can not become a truly useful and reliable analytical method either practically or scientifically without this strategy. It is planned to continue the basic interpretation of NIR spectra with focusing on various foodstuffs, and thus hopefully provide a useful analytical technique for many of industrial needs.
(Received January 6, 2005)
Keywords : near-infrared spectroscopy; portable spectrometer; spectral analysis; discrimination; plastics; foodstuffs.
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