Vol. 4 9, No. 7
July, 2 0 0 0
Toshiro Matsui and Kiyoshi Matsumoto*
*Department of Bioscience and Biotechnology, Division of Bioresource and Bioenvironmental Sciences, Graduate School, Kyushu University, 6-10-1, Hakozaki, Higashi-ku, Fukuoka 812-8581
(Received 16 February)The development of an analytical evaluation of the physiological function of food components is reviewed. In vitro and/or in vivo evaluation methods of the prophylaxes in hypertensive and diabetic diseases by food components are extensively discussed. Other food functionalities used to maintain homeostasis are also discussed.
Keywords : physiologically functional food; hypertension;diabetes.
Toshihiro Yamada, Satoshi Hirano, Kazuhiro Kobayashi, Takanobu Sakurai, Ichinari Takaki, Masaharu Tanaka, Yasuhiro Nagao, Yukimasa Azuma, Katsuhiro Date, Katsutoshi Ohno, Masaru Chiba and Yoichi Nobuhara*
*Central Research Institute, Nissin Food Products Co., Ltd., 2247, Noji, Kusatsu-shi, Shiga 525-0055
(Receiverd 1 February 2000, Accepted 6 March 2000)The presence of unidentified styrene trimers (NST-12-1 and NST-12-2) was confirmed in the eluted substance of polystyrene. Both compounds were two diastereomers of 1-phenyl-4- (2-phenylethyl) tetralin, which were proved to be the 1,4-cis (NST-12-1) and 1,4-trans (NST-12-2) configuration by instrumental analysis and chemical synthesis. The content and miglation of NST-12 in polystyrene products were determined by GC/MS (SIM). Furthermore, the endocrine-disrupting effects of NST-12 were tested by in vivo and in vitro assays. It appeared that NST-12 has no such effects.
Keywords : polystyrene products; styrene trimer; 1-phenyl-4-(2-phenylethyl) tetralin; X-ray crystal structure; material and migration test of NST-12; biological evaluation.
Keiji Ohe and Fumiyo Kusu*
*Tokyo University of Pharmacy and Life Science, 1432-1, Horinouchi, Hachioji-shi, Tokyo 192-0392
(Received 31 January 2000, Accepted 9 March 2000)In artificial saliva, the surface corrosion of precious dental alloys containing Au, Ag and Cu was studied by in situ specular reflection spectroscopy. The rest potentials of the alloys in contact with artificial saliva were about -0.1 V~0.1 V vs. SCE. It was found from the cyclic voltammograms of the alloys, that AgCl and/or CuCl were formed on the alloy at more positive potential than 0.1 V. The formation of AgCl and/or CuCl was also observed as a reflectivity-potential change using specular reflection spectroscopy. For an alloy containing a large amount of Au, Cl ion was adsorbed on the alloy surface. Since the formation of AgCl and/or CuCl and the adsorption of Cl ion occurred at a more positive potential than the rest potential of alloy. It seemed that these alloys were stable in the artificial saliva. To confirm the surface corrosion of the dental alloys, this in situ analytical method is thus sufficiently sensitive and useful.
Keywords : dental alloy; surface corrosion; specular reflection spectroscopy.
Takashi Shinkawa, Shunsuke Yamazaki and Hiroshi Kakishima*
*Cosmetics Laboratory, Kanebo, Ltd., 5-3-28, Kotobuki-cho, Odawara-shi, kanagawa 250-0002
(Received 30 November 1999, Accepted 14 March 2000)The determination of the polymerase chain-reaction (PCR) products by fluorescence detection HPLC which using a post-column reaction was developed. The optimum conditions were ; reactive solution, 0.5 M NaCl-20 mM Tris-HCl(pH 9.0) containing SYBR Green(1/25000); flow rate of a reactive solution, 0.3 ml/min. A reactive solution was stable for 24 hours. Under the optimized analytical conditions, the peak intensity of DNA was proportional not to the size of the base-pair, but to the concentration. The calibration curve was linear over the range 10 pg~50 ng. The relative standard deviation for 10 standard DNA solutions (500 bp-100 pg) was 1.01%. The PCR products made from mice, which sensitized with 2,4-dinitro-1-fluorobenzene(DNFB), was measured, and we succeeded in a high-sensitivity determination analysis.
Keywords : determination of PCR products; HPLC; post-column reaction; SYBR Green.
Arkin Iburaim, Masayuki Itagaki and Kunihiro Watanabe*
*Faculty of Science and Technology, Science University of Tokyo, 2641, Yamazaki, Noda-shi, Chiba 278-8510
(Received 1 February 2000, Accepted 24 March 2000)The preconcentration of copper and iron using a Teflon tube in the line-adsorption method was investigated for flow-injection analysis (FIA). A Teflon tube treated with an alkaline solution was used as an adsorbent (inner diameter, 0.5 mm; length, 6.00 m). Moreover, the conditions on the determination of copper and iron and the flow system on the FIA were examined after separation with a 0.5M HCl solution (0.15 ml) from the concentration Teflon tube. The copper and iron were determined with 2-(5-bromo-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino] aniline (5-Br-PSAA) by spectrophotometry at 558 nm. Copper(II) was determined directly after elution. On the other hand, iron(III) was determined with 5-Br-PSAA after reduction to Fe(II) with ascorbic acid. The chemical species on the adsorption was estimated to be a metal-hydroxide cation based on the elution behavior. The optimum conditions were as follows: concentration pH, 11; adsorption flow rate, 0.6 ml min-1; adsorption time, 30 min; concentration tube length, 6 m; 5-Br-PSAA, 2.0×10-4 M (0.4 ml min-1); ascorbic acid, 0.01 M(0.2 ml min-1); carrier, 0.1 M HCl(0.6 ml min-1). The copper(II) was determined over the range 0.3~16 ppb; iron(III) was 0.6~16 ppb. The results of trace-amount determinations of copper(II) and iron(III) in tap water showed good agreement with the values obtained by graphite-furnace AAS and ICP-AES.
Keywords : stepwise spectrophotometric determination; flow injection analysis; on-line concentration on Teflon-tube; 5-Br-PSAA.
Tomomi Iwamura, Kiwao Kadokami, Daisuke Jin-ya and Kyoko Tanada*
*Kitakyushu City Institute of Environmental Sciences, 1-2-1, Shin-ike, Tobata-ku, Kitakyusyu-shi, Fukuoka 804-0082
(Received 3 March 2000, Accepted 12 April 2000)A method for the simultaneous determination of organotins (monobutyl-, dibutyl-, tributyl-, monophenyl-, diphenyl- and triphenyltin) in biological samples has been developed using ethyl derivatizaion and isotope dilution GC/MS. After the addition of deuterated organotins as internal standards to a homogenized biological sample, organotin compounds were extracted with 1 M HBr-methanol/ethyl acetate (1:1); the extract was filtered and added to a saturated NaBr solution. The sample solution was then extracted with ethyl acetate/hexane (3:2), and the extract was mixed with hexane. The organic layer was dehydrated and concentrated. The concentrate was mixed with a buffer solution (pH 5.0) and NaBEt4 solution to derivatize target organotins. Then, 1 M KOH-ethanol was added to the derivatized sample solution and the mixture was shaken for 1 hour to decompose any fat. After saponification, ethylated organotins were extracted with hexane, and the extract was first dehydrated and then concentrated. The sample was cleaned up using a florisil cartridge column. Determination was carried out by GC/MS-SIM. The results of overall recovery tests at µg/kg levels showed that the mean recovery was 123% and their mean relative standard deviation was 12.5%. The detection limits of the method ranged from 0.13 to 6.6 µg/kg.
Keywords : organotin; biological sample; ethylation; isotope dilution GC/MS.
Kyue-Hyung Lee, Mitsuko Oshima and Shoji Motomizu*
*Department of Chemistry, Faculty of Science, Okayama University, 3-1-1, Tsushimanaka, Okayama 700-8530
(Received 18 January 2000, Accepted 7 March 2000)Ultratrace elements in natural water samples were determined simultaneously by air-segmented flow-injection/inductively coupled plasma-mass spectrometry (SFI/ICP-MS). A small volume of the sample solutions (80 µl) was introduced into a nebulizer by an air-segmented flow-injection (SFI) system, and a maximum of fifteen elements were measured during each run. A chitosan-based chelating resin containing functional groups of iminodiacetate was used to separate and enrich analyte metal ions. A 50-fold preconcentration using 50 ml of sample solutions was achieved by the proposed method, where 1 ml of 0.1 M nitric acid was added to residues after drying the chelating column effluent. At pH 6, several heavy metals (Fe, Ni, Co, Cu, Zn, Ag, Cd, Pb and U) and rare earth elements (REEs) were quantitatively retained on the chelating resin column, whereas alkali and alkaline earth metals were eluted from the column by rinsing with 5 ml of a 0.2 M ammonium acetate solution. Metals adsorbed on the chelating resin column were recovered by elution with 10 ml of 1 M nitric acid. The proposed method was applied to the determination of trace elements in several natural water samples, such as river water and mineral drinking water.
Keywords : ICP-MS; segmented-flow injection; chelating resin; chitosan; iminodiacetic functional group; natural waters; preconcentration.
Toshiaki Hiyama and Tomio Kageyama*
*Japan Nuclear Cycle Development Institute (JNC), 4-33, Muramatsu, Tokai-mura, Ibaraki-ken 319-1194
(Received 6 January 2000, Accepted 17 March 2000)A controlled-potential coulometry is proposed for the determination of plutonium in the presence of iron. Iron interferes because the differences in the formal potentials of the Fe2+-Fe3+ and Pu3+-Pu4+ couples are very small in sulfuric acid. Even small quantities of iron relative to plutonium can cause an appreciable error in the analysis, since the equivalent weight ratio of Pu:Fe is about 4:1. In order to remove the interference of iron, 1,10-phenanthroline was used as a complexing agent with iron. 1,10-phenanthroline reacts with iron(II) to form the complex, and the start of the oxidation potential was shifted to the positive side of about 100 mV from that of iron. To obtain the most accurate result, the mole ratio of 1,10-phenanthroline to iron was required to be more than 20-fold. The relative standard deviation was less than 0.3%.
Keywords : controlled-potential coulometry; plutonium; iron; 1, 10-phenanthroline.
Zhidong Chen and Tsutomu Nagaoka*
*Department of Applied Chemistry, Faculty of Engineering, Yamaguchi University, 2-16-1, Tokiwadai, Ube, Yamaguchi 755-8611
(Received 18 February 2000, Accepted 15 March 2000)In this paper, we present a novel way to design a self-assembled monolayer, based on molecular imprinting protocols, for the selective recognition of hydrophobic molecules. A monolayer of octadecanethiol, templated with n-hexadecane, was fabricated on a gold substrate, and its voltammetric behavior was examined with vitamin K1 and K3. The monolayer film showed a voltammetric response only to hydrophobic vitamin K1 molecules, while a film without the hexadecane template showed neither a peak assigned to vitamin K1 nor K3. The results demonstrate that the present technique can be used as a simple and highly selective surface-designing tool for the fabrication of a self-assembled monolayer based electrode.
Keywords : molecular imprinting; self-assembled electrode; vitamin K; molecular recognition.
Hajime Goto, Jin-Ming Lin and Masaaki Yamada*
*Department of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University, 1-1, Minami-Ohsawa, Hachioji, Tokyo 192-03
(Received 2 February 2000, Accepted 16 March 2000)New heterogeneous chemiluminescence(CL) reaction media based on barium oxide(BaO) CL reaction system were developed using peroxomonosulfate(KHSO5) and hydrogen peroxide(H2O2) and nitrite(NO2-). It is known that KHSO5, an oxidizing agent, is decomposed by a metal ion catalyst(Co2+) to yield reactive species(Co3+, SO4-, etc.), which are strong oxidizing agents. On the other hand, peroxynitriteONOO- and nitrogen dioxide radical(NO2) obtained by reaction between H2O2 and NO2- are also powerful oxidizing agents. We have thus tried to immobilized these active species on the surface of BaO in order to improve the capabilities of BaO as not only CL, but also various reaction media.
Keywords : chemiluminescence reaction medium; barium oxide; sulfate ion radical; nitrogen dioxide radical; nucleic base.
Keiji Gamoh* and Hiyoshizo Kotsuki**
*Faculty of Education, Kochi University, 2-5-1 Akebono-cho, Kochi 780-8520
**Department of Chemistry, Kochi University, 2-5-1 Akebono-cho, Kochi 780-8520
A method of the formation of a molecular template on bovine serum albumin (BSA) under a high-pressure condition has been developed. The BSA-adsorbed aminopropylsilica gel (APS-BSA) was suspended with cholestenone (4-cholesten-3-one) as a template molecule in aqueous ethanol, and the suspension was left standing under 200-800 MPa for 4-12 hrs. The solid residue was thoroughly washed with THF and ethyl acetate to extract cholestenone. The "templated"-APS-BSA gel selectively adsorbed cholestenone as the substrate in the suspended solution, including cholestenone. Also, the gel was used as a liquid-chromatographic packing material to examine its substrate- or structure-selectivity for some steroid compounds. A large-capacity factor for cholestenone was observed when an aqueous methanol solution was used as a mobile phase. This shows that the templated-APS-BSA gel has an appreciable molecular-recognition ability, and can be used as a selective adsorbent for a chromatographic separation. The selectivity has persisted for several months after intermittent applications. Furthermore, the templated-APS-BSA gel was analyzed using an IAsys plus, bio-molecule interaction analysis system by a resonant-mirror detector, to observe the binding amounts of the substrate. Only cholestenone showed an extremely higher value of the binding efficiency with the gel compared to any other steroid compounds tested. It has thus been shown that high pressure can be a parameter for molecular template formation on BSA, which means that a packing material with a highly selective molecular recognition site could be conveniently produced.
Keywords : molecular template; bovine serum albumin; high pressure; aninopropylsilica gel; 4-cholesten-3-one.
Kenji Kurihara and Fumiyo Tanoue*
*Analysis Center, Dainippon Ink & Chemicals, Inc., 631, Sakado, Sakura-shi, Chiba 285-8668
(Received 31 January 2000, Accepted 15 March 2000)Keywords : triglyceride; fatty acid methyl ester; thermal extraction; high-frequency heating; GC/MS
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