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Volume 46, Issue 5
Displaying 1-13 of 13 articles from this issue
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Minoru OKUMURA, Yasushi SEIKE, Kaoru FUJINAGA, Naoaki YANO1997 Volume 46 Issue 5 Pages 329-333
Published: May 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA lead-loaded chelating resin (PbR) column is proposed for a simple field determination of dissolved sulfide (total of H2S, HS-, S2-) in environmental water samples. The PbR was prepared as follows. A chelating resin (100200 mesh, Bio Rad Chelex 100 chelating ion-exchange resin, 50 g) was mixed with 500 ml of a 0.001 M lead nitrate solution for 2 hours, filtered off, and mixed with 500 ml of artificial seawater for 10 min. A 0.7 ml (0.15 g) portion of the thus-prepared PbR was put into a glass column of 4.0 mmφ×80 mm (length of PbR layer, 55 mm). Ten milliliters of a water sample were taken into a graduated syringe and 0.5 ml of a buffer solution (pH 6.8) added. For the determination, after the solution in the syringe was passed through the PbR column at a flow rate of 4 ml min-1 the length of a black-colored layer appearing in the column was measured. The length of the colored layer was proportional to the concentration of dissolved sulfide in the water. Up to 200 μg sulfide-S can be determined with a relative standard deviation of 4.0% (n=10). The PbR column method is applicable to field determinations of dissolved sulfide in seawater and brackish water as well as fresh water.View full abstractDownload PDF (952K) -
Seiya NAGAO, Yasuhiro SUZUKI, Yuzuru NAKAGUCHI, Muneaki SENOO, Keizo H ...1997 Volume 46 Issue 5 Pages 335-342
Published: May 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSHumic substances play an important role in the transport of trace metals and insoluble organic materials. They are also considered to be precursors of trihalomethane in aquatic environments. The direct measurement of humic substances was carried out with a three-dimensional fluorescence spectrophotometer after filtering natural-water samples through a GF/F glass fiber filter. Because the influence of the humic concentration, pH and ionic strength on the three-dimensional excitation emission matrix spectra is negligible, the proposed method can be directly applied to the characterization of humic substances in freshwater samples (humic concentration 0.510 mg l-1, pH 69 and ionic strength <0.04 M) and sea-water samples (ionic strength 0.75 M). Humic substances in river, lake and pore water samples exhibit 23 peaks at excitation 305340 nm/emission 415440 nm and excitation 250270 nm/emission 440450 nm. These peak positions correspond to those of fulvic acids isolated from soil.View full abstractDownload PDF (1738K) -
Jun YANO, Ken-ichi YOSHIKAWA, Akira KITANI1997 Volume 46 Issue 5 Pages 343-349
Published: May 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAniline and several aniline derivatives were electropolymerized with two different electrolysis modes: potential-sweep electrolysis and constant-current electrolysis. The voltammetric and chronopotentiometric responses during electropolymerization led to two polymerization mechanisms: radical-coupling polymerization and incorporation-oxidation polymerization. The latter polymerization proceeds as follows: (1) During the initial stage a seed polymer with a low molecular weight is electrodeposited on the electrode surface. (2) The seed polymer is electro-oxidized and cation radicals are generated in the seed polymer. (3) The cation radicals oxidize dissolved monomers and incorporate the oxidized monomers. This polymerization was found to give highly conductive polyanilines. On the basis of the fact that the incorporation-oxidation polymerization obeyed Faraday's law, the electron number of the polymerization reaction of aniline was analyzed coulometrically. The determined number implied that the polymeric backbone consisted mainly of benzenoid structures, and that 2.77 anions were doped per an aniline unit.View full abstractDownload PDF (1447K) -
Tomokazu TANAKA, Motoya MATSUNO, Hiroshi KAWAGUCHI1997 Volume 46 Issue 5 Pages 351-355
Published: May 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn radio-frequency (rf) glow-discharge mass spectrometry with a Grimm-type ion source, a positive bias voltage was applied only to the aperture of the ion source, while the anode was grounded. The ion signals measured in this way were greater than those obtained when the bias voltage was applied to both the anode and the aperture. The signal-to-background ratio for a ZrO2 sample became maximum at an aperture voltage of 55 V; it was ca. 20-times higher than that at 0 V. The maximum signal intensity was always obtained at this voltage, independently of the rf power and sample thickness. The interference of rf noise with a signal measurement could be completely suppressed by grounding the anode in this arrangement.View full abstractDownload PDF (976K) -
Xiu-Feng GAO, Hong Seok JI, Kazunori IKEBUKURO, Shigeaki BABA, Isao KA ...1997 Volume 46 Issue 5 Pages 357-365
Published: May 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSAn accurate, simple, less time-consuming and sensitive chemiluminescence(CL)-FIA method has been established for the determination of sulfated bile acids (SBA) based on two kinds of immobilized enzymes. After SBA is desulfated under catalysis of a bile acid sulphate sulfatase immobilized in an enzymatic reactor, it is changed into 3β-hydroxyl bile acids. The formed 3β-hydroxyl bile acid reacts upon nicotinamide adenine dinucleotide(β-NAD+) under another catalyst of 3β-hydroxysteroid dehydrogenase coimmobilized, and is changed into 3-ketosteroid; at same time β-NAD+ is turned to nicotinamide adenine dinucleotide (NADH). NADH reduces molecular oxygen in the carrier to O2- and hydrogen peroxide (H2O2) in the presence of l-MPMS as an electronic mediator. Last, the produced O2- and H2O2 react with the luminol reagent from another tubing line, and give out light in the presence of POD. Consequently, SBA can be determined by the CL intensity. Based on the principle mentioned above, and our FIA manifold as well as the experimental results optimized in the paper, a kind of new-type analytical instrument for clinic tests of SBA in urine or blood will be developed. The sampling frequency of the method is 30 sample/h, and its relative standard deviation is less than 2.2%. The calibration curve of the method also shows good linearity over a range of 0.112 μM glycolithocholic acid 3-sulphate as a standard.View full abstractDownload PDF (1671K) -
Masaru TOKUHARA, Azuma KIDO, Kazuhiko YASUDA, Kouzou KIDO1997 Volume 46 Issue 5 Pages 367-374
Published: May 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe authors have developed a simple and convenient analytical method for determination of 12 kinds of offensive odor substances (acetaldehyde, propionaldehyde, iso-butyraldehyde, butyraldehyde, iso-valeraldehyde, valeraldehyde, ethylacetate, iso-butanol, methyl iso-butyl ketone, toluene, xylenes, styrene) in air. A glass tube (4 mm i.d.) packed with 80 mg of Tenax TA (35/60 mesh) and 150 mg of Carboxen 569 (25/45 mesh) was used to collect the substances. After collecting them, the tube was set to an automatic thermal desorption device (ATD). Using thermal desorption, the analytes were introduced into GC; they were then determined by GC/MS-SIM. The overall recoveries were up to 91%, and the relative standard deviations were 2.27.8%. This method was applied to determine offensive odor substances in not only ambient air, but also emission flue gas of a factory. The method can determine analytes at sub ppb levels, which are 1/102 to 1/105 times as low as the most strict regulation standards in The Offensive Odor Control Law. The collected samples were stable for 3 days.View full abstractDownload PDF (1606K) -
Hiroyuki NAGASAWA, Masahisa ENOMOTO1997 Volume 46 Issue 5 Pages 375-379
Published: May 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA new sampling apparatus for the liquid-phase dissolution and graphite-furnace AAS technique has been developed in order to examine the distribution of trace metallic impurities on a silicon wafer. The apparatus is equipped with five indicater-rods and a wafer-moving stage for collecting metallic impurities at different areas on a wafer. Although the detection limit is raised with decreasing the sampling area, it reactes 108 to 109atoms cm-2 when a hydrofluoric acid solution of 20 μl is used for determing one metallic element in a sampling area of 1225 mm2.View full abstractDownload PDF (957K) -
Susumu KAWAKUBO, Kiyoshi OGIHARA, Masaaki IWATSUKI1997 Volume 46 Issue 5 Pages 381-385
Published: May 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA sensitive and simple catalytic spectrophotometric method for the determination of molybdenum has been developed using the molybdenum-catalyzed oxidation of L-ascorbic acid with hydrogen peroxide in the presence of ο-phenylenediamine to produce quinoxaline derivatives. The absorbance of the solution was measured at 340 nm for the determination of molybdenum after reacting for 5 min at pH 3.2 and 25°C and readjusting the pH of the solution to 1 with hydrochloric acid to stop the reaction. The calibration graph was, linear up to 4 ng/ml of molybdenum. The detection limit was 0.03 ng/ml (0.2 ng). The proposed method was successfully applied to river-, rain- and tap-water samples.View full abstractDownload PDF (857K) -
Kunihiro WATANABE, Satoshi ABE, Masayuki ITAGAKI1997 Volume 46 Issue 5 Pages 387-390
Published: May 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIn a fluorometric determination a lower fluorescence intensity of excess reagent allows for a higher sensitivity. The fluorescence intensity of 2, 2'-bipyridyl (bipy) is lower than that of 1, 10-phenanthroline, which is the typical chelate reagent of N, N coordination. Therefore, the fluorometric properties of metal complexes formed with bipy were examined in an aqueous solution in order to determine metals by fluorometry with bipy. As a result, it was found that gallium reacted with bipy to form a fluorescence complex, which yielded fluorescence emission with an excitation wavelength of 305 nm, an emission wavelength of 325 nm, a fluorescence quantum yield of 0.042 and a molar absorptivity of 12200 l/cm mol at 305 nm. The detection limit of 0.8 ppb was accomplished under the most suitable conditions (pH of 5.0, temperature of 25°C, and bipy concentration of 3.8×10-5M). Though the fluorescence quantum yield of the complex was quite small, the lower detection limit mentioned above was obtained due to the low fluorescence intensity of bipy.View full abstractDownload PDF (650K) -
Shigeru TAGUCHI, Kenji TAKAYOSHI, Issei KASAHARA1997 Volume 46 Issue 5 Pages 391-394
Published: May 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAn on-line preconcentration method incorporated with a membrane filter for the determination of trace nitrite in water was studied. Nitrite was reacted with 4-aminobenzenesulfonic acid to be converted into 4-sulfobenzenediazonium ion, then coupled with N-(lnaphtyl)ethylenediamine to form an azo dye. A solution of benzyldimethyltetradecyl-ammonium was added to the solution at pH 10 where the azo dye is an anion. One ml of the solution was loaded from an injector to the line, and the azo dye was collected on a cellulose nitrate membrane devise attached to the line as an ion-associate with a cationic surfactant. The azo dye on the filter was eluted with an acidic medium of pH 1, which was loaded from the same injector. The absorbance at 550 nm due to the azo dye was monitored with a UV/VIS detector. The calibration graph was linear up to 100 μg dm-3 NO2-; the detection limit was defined as three-times the standard deviation of the blank on 3.3μg dm-3 NO2-. This method has the following advantages: free of any organic solvent, small sample volume, high sensitivity, and low analysis cost. The recoveries of the nitrite added to river-water samples were satisfactory.View full abstractDownload PDF (660K) -
Fumiaki YOKOTA, Toshio ISHIZUKA, Hisashi MORIKAWA1997 Volume 46 Issue 5 Pages 395-400
Published: May 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIn order to determine impurities (eleven elements) in vanadium carbide (VC) by inductively coupled plasma atomic emission spectrometry (ICP-AES), a sample dissolution procedure using acids was examined. After a 0.25 g amount of vanadium carbide powder sample was taken in a Teflon pressure vessel, 2 ml of nitric acid (1+1) and 2 ml of hydrofluoric acid (1+1) were added. The vessel was then sealed and kept at 160°C in a drying oven. The time taken to decompose depended on the sample (16 or 40 h). The mixture was filtered so as to remove the small amount of free carbon which existed in the sample, itself, and could not be decomposed by these acids. The filtrate was transferred to a 100 ml calibrated flask with 20 ml of 4% boric acid, and diluted with distilled water. Eleven elements (Al, Ca, Co, Cr, Fe, Mn, Mo, Ni, Si, Ti and W) were determined by ICP-AES. The matrix effects on the background levels and the emission intensities of the elements were compensated by using matrix-matched standard solutions for calibration. Eleven elements in commercial VC powder samples were determined with good the precision. For most elements, the values obtained by the proposed method were found to be in good agreement with both those obtained by high-pressure acid decomposition with atomic absorption spectrometry and those obtained by the fusion-acid method using potassium nitrate with ICP-AES. The detection limits were 0.18 μg g-1 for Mn to 6.5 μg g-1 for W.View full abstractDownload PDF (1164K) -
Makoto TORIGAI, Tong OUYANG, Kiyoshi IWASHIMA, Masahiro OSAKO, Masaru ...1997 Volume 46 Issue 5 Pages 401-406
Published: May 05, 1997
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSMicrowave digestion (MWD) with two kinds of acid mixtures (HCl-HNO3-HF, HClO4-HNO3-HF) was investigated for the simultaneous determination of six toxic elements (arsenic, antimony, chromium, cadmium, nickel, lead) in municipal-waste incineration fly ash (MWIFA) using inductively coupled plasma atomic-emission spectrometry (ICP-AES). The present investigated method was applied to the analysis of two certified. reference materials (BCR No. 176, NIST 1633b); further the analytical results were compared with those obtained by alkaline fusion with LiBO2·2H2O. The analytical results by MWD with an acid mixture of HCl-HNO3-HF were in good agreement with both certified and reference values for five elements, except for chromium, which requires a further alkaline fusion step for its complate recovery. The results by MWD with HClO4-HNO3-HF were in good agreement for all six elements with both certified and reference values, and comparable to those obtained by the standard alkaline fusion method. MWD with HClO4-HNO3-HF is, therefore, suitable for the rapid and simultaneous determination of these elements contained in MWIFA by ICP-AES, and has been successfully applied to the analysis of actual samples.View full abstractDownload PDF (1184K) -
Yasumasa SAYAMA1997 Volume 46 Issue 5 Pages 407-408
Published: May 05, 1997
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (475K)
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