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Volume 48, Issue 5
Displaying 1-10 of 10 articles from this issue
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Hiroko Kawamoto, Osamu NOZAIU1999 Volume 48 Issue 5 Pages 471-476
Published: May 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSWe have developed a novel flow-cell reactor by packing immobilized horseradish peroxidase (HRP) into the flow cell (teflon tube; 0.96 mm i.d; 25 cm long) of a chemiluminescence detector (JASCO, 825-CL), and a highly sensitive determination method for hydrogen peroxide assay by flow injection-chemiluminescence. HRP immobilized gels were made according to Nakane's method using the gels (Fujibo, Chitopeal BCW-3001, 74210 μm). The activity of the HRP immobilized gels was stable over a period at one year at 4°C in a stock solution (phospate buffer, 0.1 mol/l, pH 6.5). Using the flow cell reactor enabled to us to start chemiluminescent reaction and to detect the light emission simultaneously just in front of the photomultiplier of the chemiluminescence detector by automatical mixing the chemiluminescent reagents. The optimal conditions for detecting hydrogen peroxide (010 μmol/l) were that the luminol solution was 0.56 mmol/l, and the flow rate of the HPLC pumps was 0.1 ml/min. The intra-assay reproducibility for H2O2 (4.85 μmol/l) was 2.40% (n=11), and the detection limit was 10 pmol. This method was applied to the assay of glucose, which was converted to H2O2 with glucose oxidase, resulting in intra-assay reproducibilities of 2.79%, 4.85%, 5.70% for standard glucose solutions of 2.7 mmol/l, 5.4 mmol/l and control serum (5.0 mmol/l), respectively.View full abstractDownload PDF (1020K) -
Keiro HIGUCHI, Akiko INOUE, Hiromitsu TAMANOUCHI, Takayasu HATTORI, Sh ...1999 Volume 48 Issue 5 Pages 477-482
Published: May 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA new portable flow injection system was developed for on-site chemical analysis, which allows the rapid analysis of aqueous samples at sampling sites. The system comprises a newly designed double-plunger micro pump, a six-way sample injector, a reaction coil in a thermostated compartment and a detector. All of these units are connected with 0.5 mm i.d. PTFE tubing. A visible detector is assembled using a maximum wavelength of 525 nm of a light-emitting diode (LED) and 540 nm of an interference filter. The system is of the one-box type, whose dimensions are 160(W) × 160(H) × 320(D) mm, and is easy to carry to the analysis site; the weight is 8 kg. A thermostated compartment is incorporated into the proposed system in order to be used outdoors, where temperatures are changeable. The system can work with DC 12 V as well as AC 100 V; therefore, a car battery or a portable battery can be used as the power source. The analytical data can be memorized in IC cards or a note-book personal computer connected with a RS232C cable. Furthermore, software on the market can be easily used. By using the proposed system, the on-site determination of nitrogen oxides, such as nitrate and nitrite, could be carried out. Calibration graphs for nitrate and nitrite ions were linear over ranges of 0 to 1.0 ppm and 0 to 100 ppb of N-NO3- and N-NO2- with good precision ; the sampling rate was 40 50 samples per hour. The detection limit for N-NO3- and N-NO2- was 0.5 ppb. By using the proposed system, the on-site determination of nitrate and nitrite in river water samples was carried out. The relative standard deviations of ten injections were 0.65% for nitrate and 0.15% for nitrite. Furthermore, nitrate and nitrite in biological samples as a metabolic products of nitric oxide, which have attracted a lot of attension as a messenger of diverse physiological processes, were also determined on-site with high sensitivity. By using a car battery as a power source, the proposed system worked continuously. In addition, it worked for about 5 hours continuously with a portable battery.View full abstractDownload PDF (1154K) -
Takatoshi MATSUMOTO, Kazutoshi TANABE, Kazumitsu SAEKI, Toshio AMANO, ...1999 Volume 48 Issue 5 Pages 483-489
Published: May 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSAt present, there is a strong social need to develop a rapid plastic- wastes discrimination system for recycling plastics. The possibility to discriminate many kinds of plastics rapidly by combining _near-infrared spectra measurements and neural network analyses was examined. For that purpose, the near-infrared spectra in the 1.32.3 μm wavelength region were measured for about 300 samples of 51 kinds of plastic, and normalized second-derivative spectral data were trained in a three-layered perceptron-type neural network. As a result of a discrimination test using the spectral data averaged for sample groups produced by a cluster analysis, the system showed an overall performance of 77% to discriminate 51 kinds of plastic. The possibility to develop a practical plastics discrimination system using this approach was demonstrated.View full abstractDownload PDF (918K) -
Akinori ISOZAKI, Sachiko KUDOU, Hisomu NAGASHIMA, Tadao OKUTANI1999 Volume 48 Issue 5 Pages 491-497
Published: May 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThis paper describes a simple and sensitive method for determining selenium in organic selenium compounds by ion chromatography with an oxygen-flask-combustion method. An anion-exchange column packing with porous poly(vinyl alcohol)gel (Shodex IC IF-424, 4.6 mm i.d. × 100 mm) is installed in an ion chromatograph equipped with an anion micromenbrane suppressor and a conductometric detector. 1.5mM sodium carbonate and 2.0 mM sodium bicarbonate are the optimal mobile phase for the simultaneous determination of a mixture of 9 anions (F-, Cl-, NO2-, Br-, NO3-, HPO42-, SeO32-, SO42- and SeO42-) under the following conditions: flow rate, 1.0 ml/min; scavenger, 12.5 mM H2SO4; column temperature, 30°C. Several mg of sample are burned in an oxygen flask filled with 20 ml of water as an absorbent, and water is added to make 200 ml. A 50 μl aliquot of a sample solution is injected into the column. The content of selenium by this method is in good agreement with that calculated from the molecular weight within a relative error of 2%. It was found that selenium in an absorbent from the combustion of a sample exists only in the selenite form.View full abstractDownload PDF (994K) -
Yuzo TAMARI1999 Volume 48 Issue 5 Pages 499-504
Published: May 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIn a hydride-generation system using 2 mol/l hydrochloric acid as an acid carrier and as the acidity of a measuring solution, tellurium(IV) was detected, whereas tellurium(VI) was not. Instead of 2 mol/l hydrochloric acid, however, a 3.6 mol/l hydrochloric acid solution was recommended to determine the total inorganic tellurium in hair samples. Hair samples (24 g) was digested with a mixture of nitric acid and perchloric acid, decomposed by heating on a hot-plate, concentrated up to about 1 ml until white fumes of perchloric acid appeared, and then boiled with 6 ml of 20% hydrochloric acid for 5 minutes to reduce the total tellurium to tellurium(IV). The tellurium(IV) solution was transferred to a centrifugal tube, and the solution pH was adjusted to 9 with aqua ammonia after the addition of 5 mg of iron(III). After centrifuging the tube, an iron(III) precipitation was dissolved with 3.3 ml of concentrated hydrochloric acid, and then diluted to 10 ml with water. The hair tellurium content can be determined by this method without any interferences due to a matrix or minor component of hair, although ppm levels of copper in hair interfere. In this method the recovery of tellurium(IV) added to hair samples was found to be 96.2±2.4%, and no copper was detected in measuring the sample solution. As results, the human-hair tellurium content was found to be in the range of 27 ng/g for 3 samples.View full abstractDownload PDF (934K) -
Syuji OKUYAMA, Toshiyuki MITSUI1999 Volume 48 Issue 5 Pages 505-508
Published: May 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn conventional methods, the determination of the mixed ratio for a polyester and cotton mixture in fiber has been performed by the dissolution of fibers or the difference in the specific gravity between each fiber using a large quantity of fiber. In this method, trace samples were used, and measured by infrared spectroscopy. The obtained data were used in calculations for a multivariate analysis. This method was accurate to within 3%. The mixed ratio for a polyester and cotton mixture in fiber could be accurately determined without disappearance of the sample.View full abstractDownload PDF (534K) -
Yutaka HAYASHIBE, Hiroyuki SAKURAI, Masaaki KATOU, Minoru TAKEYA1999 Volume 48 Issue 5 Pages 509-514
Published: May 05, 1999
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA fully automated flow-injection system for the spectrophotometric determination of copper and nickel ions in copper electrolyte has been developed. To detect each aquacomplex by utilizing one spectrophotometer, at first, the sum of the absorbance of copper and nickel ions was measured at a reference-path. After mixing a thiourea solution to mask copper ions as the copper-thiourea complex, the absorbance of nickel ion was measured at the sample-path. The concentrations of each element were calculated from the difference of each absorbance and from a dilution factor between the two paths. The reproducibility has been proven to be satisfactory with relative standard deviations of less than 0.8%(RSD, 30 g Cu l-1 - 15 g Ni l-1levels, n= 5). The determination limits were 1.4 g Cu l-1 and 5.0 g Ni l-1 with 75 μl sample injection. This system permits a throughput of 30 samples per hour. It is suitable for monitoring the concentration of copper and nickel ions in a copper electrolytic process stream.View full abstractDownload PDF (1020K) -
Takashi MASADOME, Yasukazu ASANO1999 Volume 48 Issue 5 Pages 515-518
Published: May 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA potentiometric flow injection determination method for cationic polyelectrolytes utilizing a flow-through-type tetraphenylborate-selective electrode detector is described. The method is based on detecting any concentration decrease of the tetraphenylborate ion by the formation of an ion associate between cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (Cat-floc) and tetraphenylborate ion. The response of the electrode detector, as a peak-shaped signal, was obtained for injected cationic polyelectrolyte samples. A linear relationship was found to exist between the peak height and the logarithmic concentration of Cat-floc with a slope of 17 mV/decade over a concentration range of 5 × 10 -5 to 1 × 10 -3 mol l-1. The detection limit for Cat-floc was 1 × 10 -5 mol l-1. The sampling rate was ca. 12 samples/h.View full abstractDownload PDF (705K) -
Eiko NAKAMURA, Naoko MIYAUCHI, Fumiaki KOBAYASHI, Hiroshi NAMIKI1999 Volume 48 Issue 5 Pages 519-522
Published: May 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn ion chromatography using a high-capacity anion exchange column, such as TSKgel-SAX, and 0.5 M of a NaCl solution as eluent, sulfate was easily eluated from the column. In order to investigate the elution behavior of sulfate, the distribution coefficient (Kd) of mono and divalent anions was determined by the chromatographic method and batch method using TSKgel-SAX(4.3 meq/ml), TSKgel-ODS-80Ts(1.2 × 10-1 meq/ml) coated with cetyltrimethylammonium ion and TSKgel-IC-anion-PW(3.0 ×10-2 meq/ml) at various concentrations of NaCl solution. A plot of log Kd vs. log of the NaCl concentration gave a straight line, the slope of which agreed with the charge of the anions. In the TSKgel-SAX column, Kd of sulfate became samller than that of monovalent anions at a NaCl concentration greater than 0.2 M. This result suggested that sulfate was easily eluated from the column in ion chromatography using a high-concentration NaCl solution as the eluent.View full abstractDownload PDF (594K) -
Sahori TAKEDA, Toshiyasu MATSUOKA, Kimihiro ISHIMURA, Shigeru AMEMIYA1999 Volume 48 Issue 5 Pages 523-530
Published: May 05, 1999
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (1575K)
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