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Volume 45, Issue 5
Displaying 1-11 of 11 articles from this issue
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Tohru MIYAJIMA, Megumi MORI1996 Volume 45 Issue 5 Pages 369-399
Published: May 05, 1996
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSThermodynamic and spectroscopic studies on the complexation equilibria of humic and fulvic acids in aqueous solutions are reviewed. Two complicating factors, i.e., polyelectrolytic and functional group heterogeneity effects inherent in the ion-binding equilibria of these naturally occurring polyacids, have been treated separately. Applicability of a Donnan model to the analysis of the proton and metal ion binding equilibria of fulvic acid standard samples and polyacrylic acid has been examined. It has been revealed that electrostatic binding as well as specific binding such as chelate and monodentate ligand complex formation play important roles in the complexation equilibria of these polyion systems.View full abstractDownload PDF (4359K) -
Hideaki KINOSHITA, Hiroto MURAKAMI, Naotoshi NAKAJIMA, Simeru KAMIHIRA ...1996 Volume 45 Issue 5 Pages 401-405
Published: May 05, 1996
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSThe magnitudes of the steady-state current at 0.65 V due to 10 μM p-hydroxyhippuryl-His-Leu (pHHHL), the substrate for angiotensin-converting enzyme (ACE), and p-hydroxyhippuric acid (pHH), the product for ACE, in borate buffer of pH 8.3 were 1.5 and 7.2 nA, respectively, using a dialysis membrane-covered plastic formed carbon electrode. The current due to the enzyme reaction at 37°C in a reaction mixture containing 1 mM pHHHL, 0.9 M NaCl and serum in the borate buffer increased linearly with time for two hours. The magnitude of the increase in current for one hour was proportional to the serum or ACE calibrator concentration. The current increase was not observed in the presence of ACE inhibitors such as captopril (25 μM) and EDTA (50 μM) nor in the absence of NaCl in the reaction mixture. Based on these results, the current increase should be due to the convertion of pHHHL to pHH by ACE in serum or ACE calibrator. The relative standard deviation for the current increase for one hour reaction in the borate buffer containing 1 mM pHHHL 0.9 M NaCl and serum (diluted 1/10) was 4% for six runs.View full abstractDownload PDF (791K) -
Kunihiro WATANABE, Tsuyoshi YAMASAKI, Masayuki ITAGAKI1996 Volume 45 Issue 5 Pages 407-413
Published: May 05, 1996
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSFlow injection analysis with chemiluminescence detection was investigated to determine small amounts of ferric ions by means of the 1, 10-phenanthroline-hydrogen peroxidesodium hydroxide system containing cationic surfactant. The present chemiluminescence method was based on the following chemical reactions. Superoxide radical anion was produced by catalytic decomposition of hydrogen peroxide in the presence of the Fe(III)-1, 10-phenanthroline complex. The superoxide radical anion reacts with 1, 10-phenanthroline to form the 1, 2-dioxetane, which emits chemiluminescnce via a excited 3, 3'-diformyl-2, 2'dipyridyl. The limit of the determination for Fe(III) was 0.1 ppb under the optimum conditions. Furthermore, we investigated the effect and role of the micelle on the chemiluminescence by spectrophotometry. Among the examined cationic surfactants, zephiramine provided the highest enhanced chemiluminescence, with a peak intensity approximately 92 times higher than that in the absence of surfactant. The concentration ratio of Fe(III) chelate {the fraction of Fe(III) chelate adsorbed on the micelle surface} was calculated to be 16.7% by using the concentration of Fe(III) in the aqueous phase. The role of the micelle was revealed through the 3D spectra of Fe(II)-1, 10-phenanthroline complex formation, that is, the micelle enhanced the rate of chelate reaction. Furthermore, the chelate was concentrated on the micelle, and reacted with hydrogen peroxide to form the superoxide radical anion; as a result, the micelle enhanced the chemiluminescence.View full abstractDownload PDF (1079K) -
Hiroshi NISHIOKA, Tetsu KUMAGAI, Tohru NAGAHIRO1996 Volume 45 Issue 5 Pages 415-419
Published: May 05, 1996
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSA flow injection system was studied for the determination of antimony(III). This method was based on the formation of a fluorescent complex with 3-hydroxy-4'-ethoxyflavone. The maximum wavelengths of its excitation and emission spectra were 420 and 475 nm, respectively. A 200μl aliquot of sample solution is injected into a carrier (H2O), which is pumped at 1.7 ml/min. The reagent solution is prepared by dissolving flavone in a mixture of 40 v/v% perchloric acid (60% ) and 60 v/v% methanol to give a 1×10-4 M solution. The reagent solution is also pumped at 1.7 ml/min. Antimony(III) in the sample solution reacts with flavone in the coil (0.5 mm i.d.×1m) to form a fluorescent complex. A linear relationship was observed between peak heights and antimony(III) concentrations in the range of 101000 μg/l. The relative standard deviation for five replicate injections was 0.3% for the determination of 100 μg/l of antimony(III). A routine sampling rate of 150 determinations per hour can be achieved by the proposed method.View full abstractDownload PDF (651K) -
Tadao FUKUHARA, Kazuo KOMATU, Shinya YAMAMOTO, Tasuku TAKAMATU1996 Volume 45 Issue 5 Pages 421-426
Published: May 05, 1996
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSAn on-line system combining semimicro liquid chromatography (LC) and 400 MHz proton nuclear magnetic resonance spectrometer (1H-NMR) with flow cells (2 mm i.d., detection volume 40 μl, total volume 400 μl) was devised. The LC column was a polymer coated ODS silica semimicro column, CAPCELL PAK C18 (1.5 mm i.d.×250 mm) and the mobile phase consisting of deuterium oxide (D2O)/acetonitrile-d3 (CD3CN)=7:3 (v/v) flowed at a rate of 100 μl/min. The effect of flow rate on T1 and signal width was not observed under semimicro LC flow rates of 100200 μl/min. The sensitivity of ethyl p-hydroxybenzoate was ca. 7 μg for the methyl group at an S/N ratio of 3, which was comparable with those reported for ordinary LC/NMR systems. This system required only 6 ml/h of expensive deuterated solvents, significantly improving cost-efficiency and allowing the use of a deuterated organic solvent so that solvent signals could be easily minimized. In addition, the detectable window for NMR signals of sample was further expanded, and the results fully supported the practical value of the semimicro LC/1H-NMR system.View full abstractDownload PDF (847K) -
Kunio NAGASHIMA, Yuee Wu, Minori KAMAYA1996 Volume 45 Issue 5 Pages 427-429
Published: May 05, 1996
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSSample solution (10 μl) was mixed with the urease solution (5 μl), which contained 1800 units urease and 25 ml glycerin in 100 ml, in the tip of a micro pipette. After standing for 20 min, the mixture (15 μl) was dropped on the pH test paper, and the reflection absorbance (λ=570 nm) of the test paper was measured by spectrophotometry. The pH test paper was prepared by placing 40 μl of 0.1 % (w/v) Bromophenol Red {pH 5.2(yellow)pH 7.0(red)} aq. solution (pH 5.2) onto the filter paper (5B) and drying it in a desicator for 12 h. A linear relation was obtained between the concentration of urea (5120 ngN/10 μl) and the reflection absorbance of the test paper. The detection limit (S/N=3) was 2 ngN/10μl. Reproducibility tests (n=7) showed that the relative standard deviation of the response was 5.5% for 30 ngN/10μl.View full abstractDownload PDF (314K) -
Yoshimi HASHIMOTO, Akiyoshi MIYANAGA, Osamu ISHIKAWA1996 Volume 45 Issue 5 Pages 431-434
Published: May 05, 1996
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSDetermination of carbonate ion by ion chromatography was investigated. The separation was performed on a TSKgel IC-Anion-PWXL (4.6 mm i.d.×35 mm) with boric acid-ethylenediamine buffer. The influence of the eluent pH on the capacity factors of carbonate and some inorganic anions was studied. Buffer at pH 10.5 gave optimum separation of the ions in terms of resolution and analysis time. A linear calibration curve was obtained for carbonate ion in the range of 1200 mg/l. As a result, this method may be useful for quantitation of carbonate ion in variable samples like digests, bath salts and tap water.View full abstractDownload PDF (419K) -
Chushiro YONEZAWA, Tatsuya KUROSAWA1996 Volume 45 Issue 5 Pages 435-440
Published: May 05, 1996
Released on J-STAGE: May 07, 2010
JOURNAL FREE ACCESSDetermination of ppt to ppb levels of U and Th in reference materials of silicon dioxide and Al has been carried out by radiochemical neutron activation analysis (RNAA) using liquid-liquid extraction with thenoyltrifluoroacetone (TTA). Samples, (0.1 to 0.5 g) together with U-Th standard samples were irradiated in JRR-4 or JRR-3M at a thermal neutron flux of (5.5 or 12) × 1013 n cm-2 s-1 for 6.0 h. After cooling for more than 1 day, the samples were dissolved with hydrofluoric acid for silicon dioxide and hydrochloric acid for Al, and the resulting solutions were finally adjusted to 1 M hydrochloric acid solutions. Neptunium-239 and 233Pa were extracted from the solutions with 0.5 M TTA-xylene. The 239Np and 233Pa were back-extracted with 10 M nitric acid and 5 M sulfuric acid, successively, and their γ-ray spectra were measured with a Ge detector. Some of the U samples were determined by correcting for the chemical yield of 239Np using 237Np as a tracer. In other cases, U and Th were determined using calibration curves obtained by a procedure similar to that used for the U-Th standard samples. Analytical results for U and Th in the silicon dioxide materials agreed to within ±20% of the certified values, while in the Al materials, the results were 6.4 to 13% lower for U and 16 to 17% higher for Th, than the certified values. The detection limits for U and Th were 12 (U) and 76 (Th) pg/g in silicon dioxide and 11 (U) and 45 (Th) pg/g in Al.View full abstractDownload PDF (929K) -
Ken-ichi AKIYAMA1996 Volume 45 Issue 5 Pages 441-446
Published: May 05, 1996
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSThis paper describes the development of a quantitative analytical method for aromatics in diesel fuels by capillary multi dimension GC-FID. Methylsilicone and SP2380 were selected for the precolumn and main column, liquid phases to separate the aromatic hydrocarbons from the paraffin hydrocarbons. Separation of hydrocarbons was recognized by GC/MS with an open split interface. From the analytical result measured by this method, it is concluded that aromatics can be separated from paraffins, furthermore, aromatics can be separated according to ring number. The analytical result shows the ratio of aromatics indicated in weight percentage using FID as a detector. The relationship of aromatics analyzed by the FIA method and SFC method showed good correlation respectively.View full abstractDownload PDF (736K) -
S. MORI, S. TAKAYAMA, Y. GOTO, M. NAGATA, A. KINUGAWA, T. HOUSAKI, M. ...1996 Volume 45 Issue 5 Pages 447-453
Published: May 05, 1996
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSThe weight average molecular weight (MW) of polystyrene samples determined in the first round robin test (RR-1) was compared with those in the second round robin test (RR-2) to analyse the difference in polystyrene standards for calibration. The data were divided into two groups: data determined at laboratories that used the standards obtained by the identical vendor in both RRs (case 1) and those using the standards of different vendors for RR-1 and RR-2 (case 2). The RR-1: RR-2 ratios for Mw in case 1 were 1.031.04 in average, but the maximum was 1.17 and the minimum 0.95. By careful adjustment of calibration conditions, the RR-1: RR-2 ratios for MW were reduced to 1.011.03. In case 2, as long as a calibration was constructed by passing through most data points smoothly, there was no distinct difference in calculated MW among standards from different vendors. The relative standard deviation of these data, obtained carefully as mentioned above, were 3.9%.View full abstractDownload PDF (1071K) -
-Determination of Trace Elements and Ultra-trace Elements-Yukiko OKADA1996 Volume 45 Issue 5 Pages 455-456
Published: May 05, 1996
Released on J-STAGE: May 29, 2009
JOURNAL FREE ACCESSIn the first study, the analytical conditions for the determination of platinum in biological samples by instrumental neutron activation analysis (INAA) were optimized. The distributions of platinum and selenium in organs of rats treated with cisplatin and sodium selenite were determined. In the second study, selenium in soybean originating from Japan, China, Formosa, Burma, Brazil, Argentina and U.S.A. was determined by INAA. The γ-ray spectrometry was three counting methods, two conventional countings for 75Se and 77mSe, and a coincidence counting for 75Se. Concentration of selenium in analyzed soybean ranged from 5200 ppb. In the third study, the contents of about 50 elements in very bitter edible plants and the less bitter edible plants were determined by INAA. Especially, the contents of Al, Mg, Mn, K, Co, Cr, Fe and Te in very bitter edible plants were higher than in the less bitter edible plants. In the fourth study, distributions of 54 elements in coal samples were determined by INAA. In the fifth and sixth study, uranium and thorium in a high purity silica and an aluminium were analyzed by radiochemical neutron activation analysis (RNAA) with anion exchange chromatography and coprecipitation of LaF3. The lower limit for the determination of uranium or thorium was found to be on the ppt level. In the seventh study, ultra-trace amounts of uranium and thorium in high purity silica, aluminium, copper and niobium oxides were determined by RNAA using the Japan Materials Testing Reactor (JMTR).View full abstractDownload PDF (400K)
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