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Volume 35, Issue 5
Displaying 1-14 of 14 articles from this issue
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Shin TSUGE1986 Volume 35 Issue 5 Pages 417-438
Published: May 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSPyrolysis-GC (PyGC) has increasingly utilized in the field of molecular chracterization of nonvolatile samples such as biological and geological materials and high-polymers. PyGC is a simple but rapid and extremely sensitive technique and often provides unique structural informations not only for ordinary solvent-soluble polymeric materials but also for intractable cured polymers with three dimentional networks. PyGC in the early stage, however, had some limitations associated with various factors involved such as the difficulty in attaining the specific pyrolysis of the samples, the insufficient chromatographic separation of the degradation products and the poor peak identification and interpretation of the resulting pyrograms. However, owing to recent developments in highly specific pyrolysis devices, highly efficient separation columns for GC, and specific identification of the peaks on the pyrograms by GC-MS, PyGC has made a great stride toward being a powerful tool for the structural characterization of high-polymers. Among these, the advent of highly efficient and chemically inert fused silica capillary columns has revolutionally changed the-state-of-the arts of PyGC. The structural informations obtained by this recent “high-resolution” PyGC(HRPyGC) are often unique and complementary to those by the conventional spectroscopic methods such as IR and NMR. In this article, the instrumental and technical aspects of HRPyGC are first discussed, and then its most recent applications to the microstructural characterization of various synthetic polymers and some natural polymers (enzyme proteins) are presented.View full abstractDownload PDF (3427K) -
Fumio NAKATA, Hiroshi SUNAHARA, Hiroshi MATSUO, Takahiro KUMAMARU1986 Volume 35 Issue 5 Pages 439-445
Published: May 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA system of an inductively coupled plasma (ICP) atomic emission spectrometer using a concentrator and a short separator columns interfaced with an on-line prereduction/hydride generator was investigated for the speciation and sensitive and simultaneous determination of selenium(IV) and selenium(VI). A 5-cm3 of sample solution was injected into the concentrator column to condense selenium(IV, VI) and then the selenium(IV) and selenium(VI) were separately eluted from the separator column with a potassium hydrogen phthalate buffer solution (5.0 × 10-4 mol dm-3, pH 6.5). The broadening of selenium(VI) caused by the use of the concentrator column was depressed by changing the separator column to sulfate-form. The eluate was directly introduced into a concentrated hydrochloric acid line and brought to a prereduction coil by a peristaltic pump. Then the mixture and a sodium tetrahydroborate solution were delivered by the pump to a gas-liquid separator. The evolved hydrogen selenide was swept into the ICP through a 50-cm3 buffer tank. The selenium emission signals were almost constant between 0.4 to 0.6 dm3 min-1 of carrier argon gas flow rate. Sensitivity enhancement by a factor of 1.7 to 2.0 was observed by introducing air just before the prereduction step of selenium(VI). The detection limits (S/N=3) of selenium(IV) and selenium(VI) were 1.6 ng cm-3 and 2.5 ng cm-3, respectively. These values show that the sensitivity of this method was hundreds times or one thousand and hundreds times higher than that of a conventional conductivity detection or a direct nebulization of the eluate to the ICP. The relative standard deviations (n=10) were 1.7% for selenium(IV) and 2.5% for selenium(VI) at the concentration level of 10 ng cm-3.View full abstractDownload PDF (1124K) -
Yasushi NAKAMURA, Yoshio KOBAYASHI1986 Volume 35 Issue 5 Pages 446-450
Published: May 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe determination of copper, chromium, lead, manganese, iron, aluminum, nickel and cobalt in gallium arsenide crystals was investigated by tungsten furnace atomic absorption spectrometry. The sample solutions were prepared and analyzed by the following procedure. The crystal samples were dissolved in hydrochloric acid and bromine in a test tube, and ammonium chloride was added. This solution was injected into a tungsten boat atomizer and dryed. Gallium and arsenic were vaporized in the pre-ashing stage below 400°C, and then ashing and atomizing were followed. Advantage of this method; with ammonium chloride, gallium and arsenic are almost completely vaporized in the pre-ashing stage. The blank test value and hence the detection limits are low without any pretreatment.View full abstractDownload PDF (920K) -
Kiyoshi AZAMI1986 Volume 35 Issue 5 Pages 451-458
Published: May 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA Carbon-13 NMR spectrum of low density polyethylene (LDPE, comonomer : propylene 0.04 mol%) was measured in o-dichlorobenzene at 25 MHz. Isolated branches of C1, C4, C5 and C6+, and a 1, 3-diethyl pair were assigned (under a precision of 0.1 ppm) by comparing the spectrum of LDPE with the spectra of model copolymers. Other smaller peaks were assigned to 5-ethyl-hexyl, tetrafunctional (ethyl, 3-ethyl-butyl), 5, 7-diethyl-octyl and a 1 -ethyl-3-tetrafunctional(ethyl, butyl) pair by comparing observed chemical shifts of LDPE with those calculated by Lindeman-Adams parameters for branches expected in LDPE. These results indicate that second and third order back-biting reactions took place in the formation process of LDPE. Terminal-part carbon atoms of various branches were quantitatively analyzed with a relative error of 10% after sensitivity correction method based on experimental results from model copolymers. The ratio of a C4 branch to a C2 branch was about 2. A C3 branch was not observed. The only branch generated from trace propylene was a C1 branch. It can be concluded from the present result that the branch generating reaction of LDPE consists mainly of first back-biting reactions with partial contributions of second, third and fourth order reactions.View full abstractDownload PDF (1120K) -
Fengying WANG, Yuri XU, Zhijun LIU, Tiezheng LIN1986 Volume 35 Issue 5 Pages 459-464
Published: May 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe interference effect of soluble alumina on the determination of Pt in the alumina supported Pt catalyst by FAAS was studied in details. Effect of alumina was severe and complicated. To suppress alumina effect, various possible releasing agents including La, Ba, Sr, Mg, Cd and Ca were examined. Among them, Ca agent was found to have the best performance for releasing Pt from alumina and the other carriers such as silica gel and molecular sieve. Using this agent, moreover, Pt could be determined by both the calibration curve and standard addition method. La agent showed relatively better performance, the most effective method was the utilization of standard addition. The other four elements were not suitable as the releasing agent. The optimal operating conditions were decided: decompose the catalyst sample containing not larger than 2.5 mg Pt with about 10 ml aqua regia through heating. After cooling, add 10 ml of 5% Ca (NO3)2-10% HNO3 solution, make it 25 ml with H2O and measure the atomic absorption signal by FAAS. The effect of 27 foreign ions on the determination of Pt using Ca releasing agent was investigated and no remarkable interference was found. The eleven catalysts containing Pt in the range from 0.07 to 15% and γ-alumina, silica gel and molecular sieve as carrier were analyzed with both the calibration method and standard addition method. The results obtained by these two methods were identical within experimental error. The overall R. S. D. was less than 3% and the recoveries in the procedure were 95105%.View full abstractDownload PDF (949K) -
Shigeru TANAKA, Kazuo YAMANAKA, Shigeru SATO, Yoshikazu HASHIMOTO1986 Volume 35 Issue 5 Pages 465-470
Published: May 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA method for the determination of sulfite in the rain water by using ion chromatography was investigated. Sulfite in the rain water is rapidly oxidized to sulfate due to the catalytic effects of Fe(III) and Mn(II) contained in the rain water. Therefore, it is difficult to determine sulfite in the rain water. The prevention of the oxidation of sulfite was tested by adding of triethanolamine (TEA) or ethylenediaminetetraacetic acid (EDTA) as the masking reagent of Fe(III) and Mn(II). As the result, it was found that sulfite in the rain water could be kept stable for more than one week in the presence of 2.5 mM TEA at pH 910 while the oxidation of sulfite could not be prevented at lower pH levels. Therefore, it is possible to determine sulfite in the rain water without the loss of oxidation by the addition of TEA during rain sampling. EDTA was also effective for the prevention of the oxidation of sulfite. However, the use of EDTA was not suitable for ion chromatographic analysis due to the appearance of EDTA peaks. A 2 mM Na2CO3/4 mM NaHCO3 eluent was used for rain water analysis due to good separation of sulfite from nitrate, so that sulfite, chloride, nitrate, and sulfite in the rain water could be determined within 15 min by ion chromatography. The detection limit of sulfite by this method was 0.03 ppm at the injection of 100 μl sample solution. The concentration of sulfite in the rain water measured by this method was 0.071.8 ppm in Yokohama, May and June, 1985.View full abstractDownload PDF (994K) -
Sadao SEGAWA, Norio INOUE, Yoshimi NAGAI1986 Volume 35 Issue 5 Pages 471-475
Published: May 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe determination method of vinyl ester content in the vinyl chloride/vinyl ester copolymers was investigated by using pyrolysis-ion exchange chromatography. Copolymer sample was pyrolyzed at 390°C for 20 min under the nitrogen flow (flow rate : 250 ml/min) and the gaseous degradation products were introduced into distilled water. The resulting solution was injected into ion exchange chromatograph in the following conditions, column packing : Toyo Soda TSKgel SCX; column size : 6.0 × 150 mm; temperature : room temperature; mobilic phase: 0.1 M phospholic acid. Content of vinyl acetate or vinyl propionate was determined from peak area of chromatogram using calibration method. Total analysis time is 30 min and the relative standard deviation are 1.4% for vinyl chloride/vinyl acetate copolymer and 2.2% for vinyl chloride/vinyl propionate copolymer.View full abstractDownload PDF (786K) -
Akihiro ONO1986 Volume 35 Issue 5 Pages 476-481
Published: May 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA method of determination of various sulfur anions in leaching solution of blast-furnace slags has been investigated. An ion-exchange chromatographic method with a controlled potential coulometric detecter was applied. The outline of the procedure was as follows. The leaching solution of blast-furnace slags was prepared by immersing 200 g of the slag samples (φ35 mm) in 500 ml of water for 3 days. One half ml of the leaching solution was injected to the column (φ9 mm×100 mm, 50°C) packed with anion exchange resin. Sulfite (SO32-), sulfide (S2-) and thiosulfate (S2O32-) anions in the leaching solution were separately eluted in 15 min with 0.5 M sodium nitrate eluent. The relative standard deviations for 50100 ppm of SO32-, S2- and S2O32- were 1.98%, 0.36% and 0.66%, respectively. In the case of coexisting of polysulfide ion (Sx2-) in sample solution, Sx2- can be eluted after the elution of SO32-, S2- and S2O32- by exchanging the sodium nitrate eluent to the one containing 100 ppm of SO32-. Sx2- is changed to S2- and S2O32- by the reaction of Sx2- and SO32- contained in the eluent. The peak area of chromatogram corresponding Sx2- eluted at 31 min was measured. The proposed method was successfully applied to the determination of sulfur anions in slag leaching solutions. Analytical results of various forms of sulfur anions, SO32-, S2-, S2O32- and Sx2-, in slag leaching solution agreed well with those obtained by the conventional method.View full abstractDownload PDF (863K) -
Nobukuni FUJIMOTO, Masaaki KATAI, Haruo MEGURI1986 Volume 35 Issue 5 Pages 482-486
Published: May 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSSimultaneous determination of ergosterol, cholestsrol, stigmasterol, campesterol and β-sitosterol in edible oil has been developed by means of high performance liquid chromatography. The unsaponifiable matter of edible oil was obtained by saponification with 0.5 M-ethanolic KOH solution at 90°C for 1 h according to a standard method. Sterols in the reaction mixture were extracted with diethylether, and the extract was evaporated to dryness at 35°C. The residue was dissolved in chloroform, and chromatographed on florisil column. After eluting with the hexane/diethylether (25 : 8), the sterol fraction was collected by eluting with hexane/diethylether (50 : 50). The eluate of sterols was evaporated to dryness at 35°C. The residue was dissolved in 3 ml of tetrahydrofurane (THF) and injected into Zorbax ODS column (4.6 mm i.d.×250 mm). The sufficient resolution was obtained by using MeOH/THF (99 : 1) as a mobile phase and column temperature at 30°C. A UV photometer was used as a detecter at 205 nm. Relationships between capacity factors and the number of carbon atoms in sterols and the effect of the double bond at C22 were studied. The chromatographic response was linear to the concentration of sterol in the range 15200 μg/ml. Sterols were identified by the retention times, and determined quantitatively by a peak height method. Three substances of sterol in ten of edible oil were detected by this method. Ergosterol and squalene in the edible oils, however, could not determined simultaneously, because they were lost a part during the pretreatment procedures.View full abstractDownload PDF (727K) -
Kunihiro WATANABE, Izuo AOKI1986 Volume 35 Issue 5 Pages 487-493
Published: May 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSComplex formation of aluminium-Schiff bases and its application to the fluorometric determination of aluminium have been studied. Bissalicylidene-ethylenediamine(BSED) used in the presence of a large amount of amino acid was hydrolyzed in the aqueous solution to liberate salicylaldehyde, which reacted with aluminium-amino acid complex to form a mixed chelate compound. The compound was transformed into a Schiff base complex in a aqueous solution by standing for 10 min at 50°C. The aluminium-Schiff base complex obtained is stable for 120 min, and has a blue fluorescence. The effect of 6 kinds of amino acids was discussed for the fluorescence intensity, so that glycine and α-alanine were superior to others. Among the derivatives of BSED discussed, bis(5, 5'-dimethylsali-cylidene)ethylenediamine(DM-BSED) exhibited an excellent property on the sensitivity with an emission maximum at 465 nm and excitation maximum at 360 nm. The optimum pH's for the fluorescence intensity were pH 5.6 and 5.4 in the presence of glycine and α- alanine, respectively. One ml of 20% ammonium acetate solution was used as buffer solution. The optimum amount of DM-BSED added was 1 ml of 0.07% DMF solution for the 25 ml of total volume containing glycine(4%, 1 ml) or α-alanine(6%, 1 ml). The composition of aluminium complex is Al : Schiff base=1:1.The fluorescence quantum efficiency of the aluminium complex was 0.35. The range of aluminium determination with accuracy is from 0.01μg to 5μg in 25 ml. Quinine sulfate solution (0.011μg/m1) was used as setting reagent.View full abstractDownload PDF (1195K) -
Keiko YOKOFUJITA, Kazuyoshi TAKIYAMA1986 Volume 35 Issue 5 Pages 494-496
Published: May 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA calcium ion selective electrode has been applied for the analysis of foodstuffs. The ashes obtained from foodstuffs were dissolved in hydrochloric acid and diluted with water to a certain volume. An aliquot portion of the solution was mixed with potassium chloride and the buffer solution of pH 5.0. After that it was diluted with water to a certain volume. The concentration of calcium was measured with a calcium ion selective electrode. Phosphate contained in foodstuffs had no effect, but perchloric acid used for ashing interfered with the present method. When the foodstuffs decomposed by perchloric acid, the calcium determination was carried out after the addition of EDTA solution.View full abstractDownload PDF (520K) -
Kikuko YOSHIMURA, Keiichiro HOZUMI, Keisuke KITAMURA, Tatsuya KITADE, ...1986 Volume 35 Issue 5 Pages 496-499
Published: May 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA glow discharge of 2-propyn-1-ol (propargyl alcohol) was applied to the surface of silica gel plates to form thin film of hydrophilic and transparent plasma-polymer. By using this plate, chemical interactions with azo dyes, amino acids, and cholesterols were examined in reference to the individual Rf-values obtained by the thin-layer chromatography. The effect of the plasma-coating process was evaluated by the ratios of Rf-values on the coated plates to those on the uncoated plates. It has been found that the change of polymer film thickness from 500 Å to 20000 Å did not alter the Rf-values of the compounds tested and the coated plates exhibited the same sharpness of the spots, developing rate of the solvents, and the standard deviations of Rf-values as the uncoated ones. Higher migration rate of azo dyeson the coated plates was observed by using benzene as a developing solvent, while higher and lower rates were obtained with the amino acids depending upon the combinations of functional groups of the compounds and the developing solvents. Cholesterol esters showed higher migration rate with the developing solvent of lower polarity. The ratios of Rf-values (coated/uncoated) thus obtained suggested certain interaction between the polymer film and the chemical structures of the organic compounds.View full abstractDownload PDF (856K) -
Eiko NAKAMURA, Hiroshi NAMIKI1986 Volume 35 Issue 5 Pages 499-501
Published: May 05, 1986
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSFor collection of mercury in air, use of KMnO4-coated glass beads was proposed. A 500 ml of glass bead (1432 mesh) was immersed in HF(5%)/KF(20 %) solution for 2 h, washed with water, placed in an eggplant-shape flask containing 200 ml of water and 10 g of KMnO4, and then dried at 80°C under reduced pressure while occationally shaking. The surface of glass beads was thus coated with KMnO4, amount of which was estimated to be 6 mg per 1 g of glass beads. Air sample, usually 150 l, was passed at a flow rate. 5 l/min through a glass column (80 mm×11 mm i.d.) packed with 3 g of the KMnO4-coated glass beads. Then, a reductant solution consisting of H2SO4(1 M) SnCl2 (5%)-NH2OH · HCl(5%) was fed to the column and mercury adsorbed was eluted for successive determination by atomic absorption spectrometry. Although interference due to sulfur dioxide was serious, it could be eliminated by passing the air sample to 0.1 M basic H2O2(0.3%). The concentration of mercury in the air varied between (421)ng/m3.View full abstractDownload PDF (638K) -
Motonori ETOH, Hisashi TOKUMORI1986 Volume 35 Issue 5 Pages T39-T42
Published: May 05, 1986
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe determination of platinum and rhodium in alumina-based catalysts was investigated by ICP-AES. The samples were fused with sodium peroxide, then dissolved with hydrochloric acid. Platinum and rhodium were coprecipitated with tellurium in 2 M hydrochloric acid solution. The precipitates were dissolved with aqua regia and evaporated to dryness. All soluble salts were dissolved with hydrochloric acid and finally diluted to 100 ml. The acid concentration of sample solution was 2 M with respect to hydrochloric acid. The recovery in the coprecipitation process was 98.5100%. There was no interference from coexisting elements. The relative standard deviation of this method was 0.30.9% in the concentration range from 0.01 to 3% for both platinum and rhodium.View full abstractDownload PDF (717K)
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