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Volume 42, Issue 7
Displaying 1-11 of 11 articles from this issue
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Masaaki IWATSUKI, Susumu KAWAKUBO, Tsutomu FUKASAWA1993 Volume 42 Issue 7 Pages 405-410
Published: July 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA flow system using a 10-cm absorption tube (2.5 mm diameter) has been designed for highly sensitive spectrophotometric analysis of aqueous samples. A hand-made flow system connected to the absorption tube was attached to a commercial double-beam spectrophotometer. The system was applied to the phenylfluorone method using a cetylpyridinium chloride dispersing agent for the determination of tin. In the present system using 0.3 ml of each sample and reagent solutions, the time for a measurement was reduced to 3 min at room temperature, compared to 30 min at 40°C in the conventional method (using a 10 ml reaction solution). The detection limit was about 1 ng/ml, approximately 1/10 of that in the conventional method. The method was successfully applied to rain samples, and was allowed to follow any change in the tin concentration with the elapsed time of precipitation.View full abstractDownload PDF (629K) -
Toshio YAO, Kenichi HAGA, Tamotsu WASA1993 Volume 42 Issue 7 Pages 411-415
Published: July 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA mediator-less enzyme electrode for the detection of hydrogen peroxide was made up by packing {one end of a glass tube (5 mm diam.)} with a graphite paste composed of 0.3 g of graphite powder, 0.18 ml of liquid paraffin, 6 mg of horse radish peroxidase (HRP) and 45μl of glutaraldehyde (20% solution). This electrode responded to hydrogen peroxide at 0 V (vs. Ag/AgCl) in the absence of a mediator such as hexacyanoferrate(II). The current response was found to be based on a direct electron transfer between the bound cofactor (ferriprotoporphyrin IX) in the immobilized HRP molecule and graphite particle. A logarithmic plot of the current response vs. the hydrogen peroxide concentration gave a straight line with a slope of 0.84 over the range of 2×10-62×10-4 M. Similarly, enzyme electrodes for glucose and uric acid were prepared by co-immobilizing HRP in the paste along with glucose oxidase and uricase, respectively, both of which were hydrogen peroxide-producing oxidases. Each of these electrodes responded to glucose or uric acid at 0 V. The current response was linearly related to the glucose or uric acid concentration, in the range of 2×10-62×10-3 M or 1×10-52×10-3 M.View full abstractDownload PDF (638K) -
Yasuhiro SUZUKI, Yoshiteru MARUMO1993 Volume 42 Issue 7 Pages 417-421
Published: July 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSFor the purpose of forensic characterization of lead shotgun pellets, a rapid and highly sensitive method for analysis of impurities is required. Graphite furnace AAS is such a method. Copper, silver and arsenic impurities in lead were measured by direct introduction of the sample solution into a graphite furnace. For solutions with a high concentration of lead, a matrix modifier was required and the absorbance of each element depended on the ashing temperature. In accordance with the results of experiments to find the optimum analytical conditions, nickel was used as the most suitable matrix modifier for arsenic, and appropriate ashing temperatures were determined for each element. Sample pieces were cut from the lead pellets and 10 mg was dissolved in 2 ml of (1:1) nitric acid by heating at 60°C for 1 h. After the solution was diluted to 10 ml with distilled water, 10 μl of this solution was introduced into the graphite furnace. For the measurement of arsenic, 10μl of 100 μg ml-1 nickel solution was introduced simultaneously as a matrix modifier. The operating conditions of the graphite furnace were as follows: drying, at 95°C for 40 s; ashing, copper at 500°C for 8 s; silver at 400°C for 8 s; arsenic at 1000°C for 8 s, atomizing, copper at 2500°C for 5 s; silver at 2000°C for 5 s; arsenic at 2600°C for 5 s. This method was applied to two NIST standard samples, No. 1132 and C2416, and nine shotgun pellet samples. The analytical results for the standard samples were in good agreement with the certified values. Comparison of the impurities measured by this method allows us to identify shotgun pellets of the same origin. This is because the impurity content showed large variations between shotgun pellet samples from different manufacturers.View full abstractDownload PDF (536K) -
Kunihiko AKATSUKA, James W. MCLAREN, Shier S. BERMAN1993 Volume 42 Issue 7 Pages 423-428
Published: July 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSAn on-line preconcentration method was studied to allow the simultaneous determination of Mn, Co, Ni, Cu, Zn, Cd and Pb in 5 ml environmental water samples by inductively coupled plasma mass spectrometry. A semiautomated system with a microprocessor-controlled high performance quaternary gradient pump and valves was used to lead and transport the mobile phase. The system includes a column containing silicaimmobilized 8-hydroxyquinoline. The pH of the samples was adjusted to 8 to improve the retention of several elements, in particular manganese. Quantitative elution from the column took 3.5 min with a 1.5 M HCl/0.6 M HNO3 mixture at a flow rate of 2.0 ml min-1. Mn and Co were determined by a standard additions technique, and stable isotope dilution was applied for Ni, Cu, Zn, Cd and Pb. The good precision and accuracy of this method are demonstrated by analyzing standard samples of riverine water (SLRS-2), estuarine water (SLEW-1) and coastal seawater (CASS-2). The detection limits of the method range from 7 ngl-1 for Cd to 130 ngl-1 for Zn.View full abstractDownload PDF (750K) -
Takashi IMAGAWA, Akira MIYAZAKI1993 Volume 42 Issue 7 Pages 429-433
Published: July 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSTo determine the number distribution of 13C in chlorobenzenes, a procedure to analyze mass spectral data by a least-squares method was established. For a species of a compound that is composed of 12C and other elements with natural isotopic ratio, the mass spectrum can be estimated from the measured mass spectrum of a standard material using the reported data of isotopic ratio. Assume that the peak intensity at a mass number k is Ak for this species. For a compound, the peak intensity IM at a mass number M will be Σ(XiAi) where the content of the species with i 13C atoms is Xi. By the least-squares method to minimize the sum of squares of IM minus Σ (XiAi), Xi can be determined for n cases from measurement of IM at more than (n+1) mass numbers. The number distribution of 13C atoms was determined by this method for chlorobenzenes generated in a thermal decomposition experiment of 13C-labeled chloroform and unlabeled hexane. The determined 13C contents and estimated mass spectra for 12C-chlorobenzenes could reproduce the measured mass spectra of the samples to good agreement.View full abstractDownload PDF (584K) -
Isao KOJIMA, Akihumi SUZUKI1993 Volume 42 Issue 7 Pages 435-437
Published: July 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSLow concentrations of lead leached from lead-glazed ceramicware into 4% acetic acid were determined by the one-drop atomic absorption spectrometry with a fuel-lean air-acetylene flame after the extraction of lead pyrrolidin-l-yldithioformate into chloroform. To a glass test tube with a stopper, 5 ml (or 10 ml) of 4% acetic acid leachate and 1 ml (or 2 ml) of 1% ammonium pyrrolidinedithiocarbamate solution were taken and the mixture was shaken with 0.5 ml of chloroform 3 times for 10 s by hand. Direct nebulization of 50 μl of the chloroform extract of lead complex gave a 3.9 times more sensitive signal height than that obtained by nebulizing a 4% acetic acid solution. With this technique, lead at 0.1 μg/ml levels in 4% acetic acid was easily determined without background correction. This method was very simple and gave very good reproducibility (RSD=1.4% at 3 μg/ml chloroform).View full abstractDownload PDF (333K) -
Yasuo NINOMIYA, Shohei ODA, Noboru OYAMA1993 Volume 42 Issue 7 Pages T93-T98
Published: July 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA new electrogravimetric analysis system based on the quartz crystal microbalance (QCM) and the flow-injection method has been developed for the determination of metallic element in aqueous solution. In this system, the quartz crystal resonator (QCR), located in the flow-through electrolysis cell as a microbalance, is a working electrode for electrolysis as well. An aliquot of sample solution (1 ml) was injected into the carrier stream (electrolytic solution) and the amount of metal in the solution measured from the frequency change of the QCR, caused by electrodeposition of metal onto the QCR. The proposed analysis system maintains stable electrolysis and allows measurement of up to ±1 Hz of the QCR frequency change due to electrodeposition of metal. The analysis system was applied to the determination of silver in photographic fixers. The analytical results showed good agreement with those obtained by ICP-AES and the relative standard deviation for the determination of silver (n=12) was 3.6%. These experimental results indicate that the analysis system can be applied to practical analysis.View full abstractDownload PDF (786K) -
Yutaka HAYASHIBE, Minoru TAKEYA, Yasumasa SAYAMA1993 Volume 42 Issue 7 Pages T99-T103
Published: July 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA derivative spectrophotometric method has been developed for the simultaneous determination of rare earth elements (Nd, Sm, Eu, Gd, Tb, Dy) in a hydrochloric acid medium. The first-derivative absorbances of the rare earth elements were calculated with a micro-processor using the Savitzky-Goray filter method. The rare earth elements, at the gl-1 level, can be determined simultaneously with excellent reproducibility. The present method does not require the mutual separation of the rare earth elements, thus allowing the rapid determination of individual rare earth elements.View full abstractDownload PDF (654K) -
Shoji MOTOMIZU, Yunhua GAO, Shinsuke ISHIHARA, Kouji UEMURA, Kazuyuki ...1993 Volume 42 Issue 7 Pages T105-T111
Published: July 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA simple and rapid automatic photometric titration method was developed for the determination of anionic surfactants in a one-phase aqueous system with tetrabromophenolphthalein ethyl ester (TBPE) as an indicator. In the presence of non-ionic surfactants such as Triton X-100, protonated TBPE reacts with cation (Q+) to form an ion associate (Q+·TBPE-), causing a color change from yellow to blue. The titrant, distearyldimethylammonium ion, was added to an anionic surfactant solution at pH 3.2, and the absorbance changes were monitored by a fiber-optic sensor with a 630 nm interference filter. The end points were read from the inflection points with differential curves. Anionic surfactants at concentrations from 10-610-3 mol dm-3 could be determined by the proposed method. The relative standard deviations of various anionic surfactants were 0.30.4%. The proposed method was applied to some practical samples, and the results, except for those of anionic surfactants possessing polyoxyethylenyl groups, were in good agreement with the results of the JIS titration method (Epton method) and a solvent extraction method with Ethyl Violet.View full abstractDownload PDF (825K) -
Yutaka NAKAMURA, Sigeto SIGEMORI, Takako TAKAHASHI, Yuichi TAKAKU, Tad ...1993 Volume 42 Issue 7 Pages T113-T117
Published: July 05, 1993
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe determination by ICP-MS of sub ppb level impurities in highly purified hydrofluoric acid has been investigated for routine analysis of factory products. Boron determination : mannitol of 4 mg was added to 100 g of the sample and the sample was evaporated to dryness on a water bath. The residue was dissolved by adding 1.2 ml of nitric acid (1+2). The final solution was made up to 10 ml with water and the boron content was determined by ICP-MS. Arsenic determination: nitric acid of 3 ml, saturated bromine water of 5 ml, and sulfuric acid (1+99) of 1 ml were added to 90 g of the sample and the above procedures were repeated to determine arsenic content. Gold determination: 100 g of the sample was evaporated to dryness on a water bath, and the residue was dissolved by adding 0.4 ml of aqua regia. The sample was evaporated to dryness on a water bath again. This residue was again dissolved by adding 0.4 ml of aqua regia, and made up to 10 ml with water to determine Au. Niobium and Tantalum determination: The sample of 100 g was evaporated to dryness on a water bath and the residue was dissolved by adding 0.4 ml of hydrofluoric acid. The sample was made up to 10 ml with water to determine Ta and Nb. Determination of other impurities: The sample of 100 g (1000 g for the determination of Th and U) was evaporated to dryness on a water bath, and the residue was dissolved by adding 1.2 ml of nitric acid (1+2). The solution was made up to 10 ml with water to determine Li, Be, Na, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Ga, Ge, Sr, Zr, Mo, Ag, Cd, Sn, Sb, Ba, Tl, Pb, Bi, Th and U. The recovery of each element was greater than about 90 %. Analytical results of these impurities in highly purified hydrofluoric acid were sub ppb level concentration. The concentration of U and Th, were 0.03 ppt and 1 ppt, respectively.View full abstractDownload PDF (536K) -
Akiyo MIZUTANI, Masamichi YOSHIDA, Naomichi ABE1993 Volume 42 Issue 7 Pages T119-T122
Published: July 05, 1993
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe determination of ultratrace iron in positive type photoresists has been studied using graphite-furnace AAS for contamination control in device lines. Photoresist was diluted with 2-ethoxyethylacetate (EEA) or 2-methoxyethanol (ME) to 3% in resin and 20 μl of the resulting solution was injected into the furnace of a Hitachi Z-8000 Zeeman graphite furnace atomic absorption spectrophotometer. The wavelength, band width and current of the iron hollow cathode lamp were 248.3 nm, 0.2 nm and 10 mA, respectively. The optimum program determined from the ashing and atomizing temperature curves, consisted of drying for 15 s at 200°C (ramp mode), first ashing for 20 s to 900°C (ramp mode), second ashing for 20 s at 1300°C (for samples diluted with EEA), or 1100°C (for samples diluted with ME) and atomizing for 10 s at 2700°C (flash mode). The background signal was lower when using ME as the solvent for sample dilution in comparsion with EEA. The detection limit of iron by the in-furnace standard addition method was found to be 1 ppb and the relative standard deviation (n=3) was 5% for photoresist diluted with ME.View full abstractDownload PDF (473K)
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