BUNSEKI KAGAKU
Print ISSN : 0525-1931
Volume 31, Issue 9
Displaying 1-27 of 27 articles from this issue
  • Shigeya SATO, Sumio UCHIKAWA
    1982 Volume 31 Issue 9 Pages 479-483
    Published: September 05, 1982
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    A highly sensitive and simple method for the spectrophotometric determination of boron was developed. Boron was found to react with hydrobenzoin in weak alkaline medium to form a complex anion extractable into benzene with crystal violet, and the measurement of the absorbance of crystal violet in the extract at 600 nm enabled the determination of boron indirectly.The recommended procedure is as follows: Take an aliquot of the boron solution (2.0 × 10-4 mol 1-1) into a 10-ml test tube. Add 1 ml of carbonate buffer solution (pH 9.4) and 0.25 ml of crystal violet solution (1.0 × 10-2 mol 1-1), and dilute the mixed solution to 4 ml with deionized water. Shake the solution with 4 ml of benzene solution containing hydrobenzoin (2.0 × 10-2 mol 1-1) for 2 min. Measure the absorbance of the organic phase at 600 nm using a 10-mm glass cell against benzene. The calibration curve obeyed Beer's law on the concentration range from 2.5 × 10 -6 mol l-1 to 2.5 × 10 -5 mol l-1 of boron, and the apparent molar absorptivity was 3.0 × 104 l mol-1 cm-1 at 20°C. It was found that many kinds of co-existing ions interfered with the determination. However, this method was applicable to the determination of boron in sea water when chloride ion and cations such as Ca (II) and Mg (II) were previously eliminated by treating the sample solution with Ag2O and cation exchanger resin. The proposed method is a very simple and rapid one, because this method does not require apparatus other than common laboratories and the evaporation to dryness of sample or removal of the excess of reagent.
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  • Classification of crude oils by cluster analysis
    Kunishige HIGASHI, Kazuyoshi HAGIWARA
    1982 Volume 31 Issue 9 Pages 483-488
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Application of cluster analysis which is a nonparametric and unsupervised pattern recognition method was studied to classify 62 kinds of crude oils in the world. These oils were produced in the Middle East, Indonesia, Africa, Mexico, Malaysia, Brunei, China, Australia, Burma, and USSR. Chromatograms of the oils were obtained by gel permeation chromatography with an ultraviolet absorption detector. Stationary and mobile phases were HSG-15 (polystyrene gel) and tetrahydrofuran, respectively. Sectional areas of each chromatogram were printed out with a data processor and ten normalized sectional areas were used as input data to perform cluster analysis. Similarity of profiles of the chromatograms was evaluated by Euclidean distance, and centroid method was used to, merge two clusters into a new cluster. Branching tree diagram was obtained from results of the cluster analysis. The proposed method was found to be effective for the classification of the crude oils.
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  • Koichi TAKAHASHI, Atsushi AOKI
    1982 Volume 31 Issue 9 Pages 488-493
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    Fluorescence quantum yields of aromatic amino acids and those derivatives are determined by measuring thermal energies which are produced by nonradiative deactivation of excited molecules. The fluorescence quantum yields of ethanol solution of DNS-Trp, DNS-Gly, and Trp excited at 360 nm, 360 nm, and 280 nm, are 0.54, 0.50, and 0.10, respectively. Spectroscopically determined values of fluorescence yields of DNS-Trp and DNS-Gly are 0.53 and 0.48, respectively. These values which are determined by two methods coincide satisfactorily. The present method can be used as a new method for quantum yield which is substantially different from ordinary spectroscopic method. We suggest a possibility of opto-calorimetric analysis of absorptive and non-fluorescent compounds. Especially, for a long wavelength emission which can not be detected by a photomultiplier, the present method gets advantage over the spectroscopic method. The experimental system is very simple, consisting of fluorophotometer (Hitachi 204 S) with some optional devices, and its measurements are also simple.
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  • Discrimination ratio of test set to training set
    Kunishige HIGASHI, Kazuyoshi HAGIWARA
    1982 Volume 31 Issue 9 Pages 494-498
    Published: September 05, 1982
    Released on J-STAGE: February 16, 2010
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    Discrimination ability was studied on an evaluation method of chromatographic profile of gel permeation chromatography with pattern similarity. A training set was composed of thirty-one chromatograms of fifteen kinds of crude oils (twelve from the Middle East and three from Indonesia). A test set was composed of sixty-five chromatograms of the crude oils of different lots and weathered oils. The weathering of the crude oil was performed by floating the oils on an open-air pool. Stationary and mobile phases of the chromatography were polystylene gel HSG-15 and tetrahydrofuran, respectively. The chromatograms were obtained by measuring absorbance at 254 nm. Section areas of each chromatogram were printed out by a data processor. Pattern similarity on a pair of chromatograms was calculated with ten section areas selected from a range of 4.567.37 count number of siphon counter. Each chromatogram of the test set was checked whether the crude oil of training set whose rank of pattern similarity became first was same with the crude oil of test set or not. Correct discrimination of the test set was 78 %. Effects of an acquisition range and the number of section areas on discrimination were studied.
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  • Yohichi SUZUKI, Ichiroh ANAZAWA
    1982 Volume 31 Issue 9 Pages 498-503
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    It is known that a mixture of phenols dissolved in a solvent containing a small amount of a metallic salt give well resolved signals for OH protons of each component. In order to determine the amount of each phenol in the mixture using this phenomenon, chemical shifts of OH protons of phenols were measured in acetone, ether, and ethyl acetate. This technique was applied to the determination of each mixture of nitrophenols, polyhydric phenols, or hydroxy benzoic acids, which was difficult to be determined by other methods, by using Cd(NO3)2 as a metallic salt. The analytical conditions for these phenols were as follows: the quantity of Cd(NO3)2 dissolved in a solvent was adjusted to 50 ppm;the appropriate solvent was acetone for nitrophenols and hydroxy benzoic acids and ether for polyhydric phenols;the optimum concentration of phenols was 5 mol% for nitrophenols, 3 mol% for polyhydric phenols and 1 mol% for hydroxy benzoic acids. Calibration curves constructed from the peak height or the area of signals for OH protons v.s. concentration were linear. The relative error was within 3 %. This method is considered to be useful as the easy and rapid analysis of various types of phenols.
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  • Hiroshi NISHIDA
    1982 Volume 31 Issue 9 Pages 504-508
    Published: September 05, 1982
    Released on J-STAGE: February 16, 2010
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    Beryllium (II) reacted with Chromazurol S (CAS, H4L) to produce two types of 1 : 2 complexes in the presence of zephiramine, one of which was in a form of mononuclear Be(HL)24- showing an absorption maximum at 612 nm and other was in binuclear Be2(OH)(HL)49-showing an absorption maximum at 525 nm. The formation equilibrium of these complexes in the range of pH 5 to 10 was examined by the spectrophotometric method. The binuclear complex was found to be produced from the hydrolysis of the mononuclear complex through the following equation;
    Be(HL)24-+1/2 H2O
    ⇔1/2 Be2(OH)(HL)49-+1/2 H+
    where zephiramine ion was not shown. The effect of anions such as chloride and sulfate ions on this equilibrium was observed. The apparent equilibrium constant decreased with the increase of the anion concentrations. The equilibrium constant was larger in the presence of sulfate ion than in chloride ion at the same concentration. In the practical spectrophotometric determination, however, these effects by such diverse ions could be successfully elimination by raising the pH to 10 so high as the above equilibrium was shifted rightward thoroughly.
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  • I. Determination of anionic surfactants by direct titration
    Akira HASEGAWA, Makoto YAMANAKA, Kazuro TSUJI, Shohei TAMURA
    1982 Volume 31 Issue 9 Pages 508-513
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    A simple and automated photometric titration system based on two-phase titration with a porous PTFE (Teflon) membrane as a separating medium of organic phase has been developed. The titrant, cationic surfactant, was added stepwise to a chloroform-aqueous sample solution mixture, which was continuously agitated vigorously by a stirring bar. The chloroform phase was continuously separated by the membrane and monitored at 610 nm. Methylene blue was used as indicator. The titration curve was obtained by converting a transmittance into an absorbance, and the end point was evaluated by extrapolation of linear portion of the curve before and after the end point. The usual samples were analyzed about within 20 min. Various anionic surfactants were analyzed by the proposed method with the coefficient of variation of about 0.9 %. The results were in good agreement with those of manual two-phase titration method developed by Weatherburn.
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  • Sachiko KATO, Yoshihisa TANABE
    1982 Volume 31 Issue 9 Pages 513-517
    Published: September 05, 1982
    Released on J-STAGE: February 16, 2010
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    Measurement of sulfur was attempted to simplify the determination of thiamine hydrochloride. Thiamine hydrochloride did not react with bromine in an acidic solution, but after heating with a 10 % NaOH solution on boiling water bath followed by cooling in ice water, it could be titrated with a 0.02 N KBrO3-KBr solution in an HCl-acidic solution. The yellowish thiamine hydrochloride solution colored by heating with NaOH was decolored by this titration and then the decolored solution returened yellow again with surplus bromine. At the time, a potassium iodide solution and starch were added to the recolored solution, which was back titrated with a sodium thiosulfate solution. The defference of both titres corresponds to the content of thiamine hydrochloride in the original solution.One mole of thiamine hydrochloride was reacted with 4.3 equivalents of KBrO3-KBr that correspond to 4.3 equivalents of bromine atom.This reaction mechanism cannotbeelucidated, however, as 4.3 equivalents of bromine are quantitatively reacted with one mole of thiamine hydrochloride, this method may be used for determining thiamine hydrochloride.The most suitable recipe is that(1050)mg of sample (thiamine HCl)are taken and the solution is heated with (1020)% NaOH for 15min.As this method is not influencedby D-glucose, thiamine hydrochloride in the commercial injections that usually contain large amounts of glucose may be determined with ease by this method.Precission of this method was within ±0.5%.
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  • Application to a fully automated method for the measurement of dissolved chemical oxygen demand in river waters
    Takashi KORENAGA, Hisayoshi IKATSU
    1982 Volume 31 Issue 9 Pages 517-523
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    A useful and sensitive system has been developed for the fully automated flow injection analysis by connecting a cheap commercial personal computer. The system has successfully been applied to continuously measure the micro amount of chemical oxygen demand (COD) in river waters. Both a potassium dichromatesulfuric acid solution and water are separately pumped up with a double reciprocating micro-pump. A 500 μl sample is injected into the flow of water with an automatic sample injector, and the solutions are merged into a carrier stream. The COD substances in samples are oxidized by dichromate for 20 min in a reaction manifold, made of poly (tetrafluoroethylene) tubing (0.5 mm i. d. × 50 m) and heated at 120 °C. The resulting solution is led into a spectrophotometric detection at 445 nm. COD values are automatically measured with this computer system by directly analyzing absorbance data, obtained via an interface unit having an analog/digital converter from the spectrophotometer. The BASIC can easily be used for computer programing. D-Glucose was used as a standard substance for calibration curves using peak heights or peak areas. A sampling rate of 10 samples h-1 could be achieved, and the detection limit and precision were 0.5 mg l-1 and 2 %, respectively. For river water samples at a COD level of (12) mg l-1, COD values obtained from peak heights were comparable to those obtained with the Japanese standard method.
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  • Takayoshi YOSHIMORI, Seiji HAYAMA
    1982 Volume 31 Issue 9 Pages 523-528
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Microamounts of carbon dioxide could be determined by the coulometric titration after conversion to ammonia with sodium amide containing some sodium hydroxide. The process was previously used only for the determination of microamounts of water and hydrogen. Both carbon dioxide and water could be determined after separation with a cold trap cooled at about -70 °C, and the method was applied to the trace characterization of gaseous materials evolved from heated polyethylenes and Teflon [poly(tetrafluoroethylene)]. The amounts of water evolved from hard (plate) and soft (tube) type polyethylenes heated at 120 °C for 1 h were 48.4 ppm and 9.9 ppm respectively. Carbonaceous materials began to evolve at 80 °C for the former and at 90 °C for the latter. Therefore, the former material was less satisfactory for containers and laboratory wares, especially for the samples for the microdetermination of carbon. Teflon rod liberated only traces of water and organic compounds at 130 °C. Carbonaceous contaminators on the surfaces of Zircaloy metals were also determined by this method. The samples were heated at 100 °C and 500 °C. The carbonaceous materials were mainly found by heating the sample at 500 °C, and were considered as rather heavy (high molecular weights) organic compounds. Simple ultrasonic washing with some organic solvents was not enough to remove the materials, and the washing procedure first with 2 N nitric acid was more effective to remove them thoroughly.
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  • Hiroko TAKEHARA, Yutaka HIRATSUKA
    1982 Volume 31 Issue 9 Pages 529-531
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The rapid method was investigated for the determination of organophosphorous pesticides: parathion, methylparathion, methyldemetone, EPN: in waste waters. Equal volumes of sample water and acetone were mixed by the ultrasonic irradiation for 5 min and centrifuged on (30004000) r. p. m. for 5 min. Pesticides in 1 μl of the water acetone mixture phase were determined by a gas chromatograph with a 2 % silicon DC QF-1 column (3 mm i. d.×2 m) at 210°C and a flame thermionic detector (FTD). The selectivity of organophosphorous compounds against hydrocarbons was improved by FTD without collector voltage. The detection limit of organophosphorous pesticides was 0.1 mg/l. The recoveries of 1.0 mg/l pesticides in waste waters containing 100 mg/1 soybean oil were (99106) % and coefficients of variation were (2.7 8.7) %. The whole procedure was completed within 20 min.
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  • Norio ICHINOSE, Chiaki SHIMIZU, Hisashi KUROKURA, Takuo INUI, Kazuhisa ...
    1982 Volume 31 Issue 9 Pages 532-534
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    In the spectrophotometric determination of dissolved organic phosphorus in sea water by the heteropoly-blue method, the dissolved organic phosphorus is usually oxidised into inorganic phosphate by potassium persulfate prior to the determination. However, for the oxidation of the dissolved organic phosphorus in anoxic waters occurring in the lake Hamana, it was confirmed. in our experiments that the potassium persulfate method was not effective because of a reducing atomosphere in the anoxic waters. In the present work, following procedure by the use of a mixture of conc. HNO3 and HClO3 which is a stroger oxidising reagent than the above was established for the preliminary oxidation and the determination of the dissolved organic phosphorus under such conditions was made as follows. Twenty ml of a sample solution is heated with each five ml of conc. nitric and conc. perchloric acid on a hot plate until dryness. After cooling to room temperature, ten ml of water and one ml of 5 N sulfuric acid is added and residue is dissolved. The solution is transferred into a 25 ml volumetric flask with water, and the blue color of phosphorus-heteropoly blue is developed by addition of 4 ml the color-producing solution containing ammonium molybdate, ascorbic acid, and some others. The absorbance is measured at 867 nm using a 5 cm cell. The proposed method is particularly applied for to determination of microamounts of phosphorus (P≥1 ppb) in the anoxic waters occurring in bay.
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  • Taketoshi NAKAHARA
    1982 Volume 31 Issue 9 Pages 534-538
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    A comparative study for the determination of tellurium by hydride generation-nondispersive atomic fluorescence spectrometry has been carried out by utilizing two types of gas handling systems; one of them involves hydrogen telluride, generated by either zinc tablet (Zn method) or sodium tetrahydroborate powder (NaBH4 powder method), to be collected in a vessel followed by introduction of the hydride into an Ar(air)-H2 flame (i.e., collection mode) and the other the hydride, produced by injecting either sodium tetrahydroborate solution into a sample solution (NaBH4 solution method [I]) or sample solution into a sodium tetrahydroborate solution (NaBH4 solution method[II]), to be introduced directly into the flame (i.e., directtransfer mode). Detection limits (S/N=3) are 4 ng, 8 ng, 2 ng, and 30 ng of tellurium in NaBH4solution methods[I] and [II], Zn method and NaBH4 powder method, respectively, and reagent blanks (corresponding to analyte mass) are 10 ng, 0, 30 ng, and 500 ng of tellurium. Analytical working curves obtained with the first three methods are linear over a range of ca. 4 orders of magnitude from the lowest determinable amount of 10-ng tellurium, whereas the last gives a linear dynamic range of ca. 3 orders of magnitude with the smallest determinable amount of 100-ng tellurium. There is little or no significant difference in reproducibility of signal measurement and interelement interference effect among these four methods.
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  • Yoshinobu WAKAMATSU
    1982 Volume 31 Issue 9 Pages 538-540
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    Sodium 2-bromo-4, 5-dihydroxyazobenzene-4'-sulfonate (BDAS) reacts with traces of lead in a weakly basic medium in the presence of cetyltrimethylammonium chloride (CTMAC) to form a water soluble ternary complex. The combining ratio of lead and BDAS in the ternary complex was shown to be 1 : 2. The ternary complex having its absorption maximum at 530 nm is quantitatively formed between pH 8.4 and 9.1, and is stable for at least 3 h. The absorbance of the complex was constant provided that the BDAS, CTMAC, and boric acid concentrations were more than 1.2 × 10 -4M, 2.0 × 10-4M, and 0.03 M, respectively. Absorbance of the reagent blank was effectively reduced by addition of excessive borate ions. The procedure is as follows: Transfer the sample solution containing up to 80 μg of lead to a 25 ml volumetric flask. Add 2 ml of 2.5× 10-3 M BDAS, 10 ml of 0.1 M boric acid (adjusted to pH 8.7 with sodium hydroxide), 3 ml of 0.01 M CTMAC, and 2.5 ml of 1 M potassium nitrate. Dilute to the mark with water and measure the absorbance at 530 nm using the reagent blank as a reference. Beer's law was obeyed over the range 0 80μg of lead. The apparent molar absorptivity of the ternary complex is 4.49 × 104 cm-1 mol-1 1 at 530 nm and the sensitivity of the reaction was 4.6 × 10-3 μg cm-2. Interfering cations such as cobalt, cadmium, copper, and zinc were masked by addition of potassium cyanide.
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  • Takejiro TAKAMATSU, Renpei NAKATA, Tomio YOSHIDA
    1982 Volume 31 Issue 9 Pages 540-542
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    Dimethylarsinate (DMA), Monomethylarsonate (MMA) and inorganic arsenic were determined in the extract of Pond Sediment CRM issued by the National Institute for Environmental Studies ( Japan). After arsenic compounds were extracted from the sample with 1 M or 10 M hydrochloric acid, they were determined by flameless atomic absorption spectrometry coupled with solvent extraction and anion exchange chromatography. As a result, the contents of arsenic compounds which could be extracted from the sample with 1 M hydrochloric acid were (5.9±0.6) ppb for DMA, (8.4±0.7) ppb for MMA, and (219±18) ppb for inorganic arsenic, while those which could be extracted with 10 M hydrochloric acid were (5.8±1.0) ppb for DMA, (53.7±5.9) ppb for MMA, and (6.37 ±0.13) ppm for inorganic arsenic.
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  • Kyoji TÔEI, Takahisa ZAITSU
    1982 Volume 31 Issue 9 Pages 543-545
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    Technical grade carrageenan and sodium cellulosesulfate were determined by colloid titration with Cat-Floc (polydiallyldimethylammonium chloride) and cetylpyridinium chloride. As the titration proceeded, the solution became turbid gradually and near the end point the turbidity increased abruptly. The colloid titration curve was recorded with Metrohm potentiograph E 336 automatically by measuring transmittance at 420 nm using Metrohm spectrocolorimeter E 1009. At the same time sulfate content in carrageenan and sodium cellulosesulfate was measured gravimetrically as barium sulfate after hydrolysis of these esters. Colloid titration is useful for the determination of polycations or polyanions. In colloid titration principally polycations are titrated by polyvinylsulfate, a polyanionic titrant and polyanions by Cat-Floc, a polycationic titrant. In this study, it is shown that cetylpyridinium chloride, an ion association reagent, can be also useful as a colloid titration titrant for the determination of polysulfate, carrageenan and cellulosesulfate.
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  • Seiji YASUDA, Koichi TANIHARA, Keiko TAMAI, Hitoo KAKIYAMA
    1982 Volume 31 Issue 9 Pages 545-547
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    The effects of metal ions on the colorimetric determination of cyanogen chloride with pyridine-pyrazolone and isonicotinic acid-pyrazolone methods were examined. Colors were allowed to develop at 25°C for 30 min after the color-producing reagent was mixed with the test solutions of metal ion and cyanogen chloride. In the presence of Cu (II) ion at higher concentrations beyond 2μg/50 ml, the initial blue color of the test solution faded gradually to red in pyridine method and to yellow-green in isonicotinic acid method. This interference could be eliminated by adding a EDTA solution in sufficient amounts to complex Cu (II) ion. EDTA was also used to prevent the formation of the precipitates of metal hydroxides under the colorimetric conditions. It was possible to determine cyanogen chloride in samples containing metal ions in concentrations up to 10 mg/50 ml for Cd (II), Co (II), Mn (II), Ni (II), Pb (II), and Zn (II), and up to 1 mg/ 50 ml for Cr (III) and Fe (II, III).
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  • Assignment of extraction constants to individual ions and solvents
    Shigeru TAGUCHI, Kazunori NAKAMURA, Takeshi HIRAIDE, Katsumi GOTO
    1982 Volume 31 Issue 9 Pages 548-549
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    It is assumed that the extraction constant, Kex, for the ion-pair extraction systems is made up of three independent constants (individual extraction constants), Ke, Ka and Ks, in accordance with the equation:
    log Kex=logKe+logKa+log Ks
    where the subscripts c, a, and s denote cation, anion, and solvent, respectively. Log K values for several cations, anions, and solvents were calculated from experimental values of log Kex by tentatively assigning the log K values 1.0 and 0.0 to perchlorate and benzene, respectively, as reference values. The cations, anions and the solvents studied were Co (III) complexes of three 2-(2-pyridylazo)-5-diethylaminophenols, perchlorate and three anionic surfactants, and benzene, toluene, and chlorobenzene. The above equation is shown to be useful in estimating the unknown value of Kex from the constants assigned to each ion and the solvent.
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  • Miho HAMADA, Shigeo TANUMA, Kozo NAGASHIMA
    1982 Volume 31 Issue 9 Pages T61-T64
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Complete analyses of hydrous minerals, muscovite and several zeolites, by inductively coupled plasma optical emission spectroscopy (ICP-OES) involving silicon and by electron probe X-ray microanalysis (EPMA) involving oxgen were carried and the results were compared with each other. For the ICP analysis, (1020) mg mineral sample was decomposed with a mixture of hydrochloric and hydrofluoric acid in a Teflon vessel, and after the addition of boric acid to mask excessive fluorine, emission intensities of the elements were recorded. Contents of water were determined by the ignition loss (muscovite) as well as thermo-gravimetric analysis (zeolite). In the EPMA analysis, the ZAF correction was employed, in which Dumcumb-Reed's atomic number correction, Casting-Reed's fluorescence correction, and authors' absorption correction were applied.
    f(x)=A{exp(u2 )Erfc (u)-B exp (v2) Erfc(v)}
    Empirical formulas of muscovite from Fukushima pref. obtained by ICP and EPMA analyses are as follows :
    ICP (K0.84Na0.10Ca0.01)∑0.95(Al1.73Fe0.19Mg0.01)∑1.93- (Al0.80Si3.20)∑4O9.85(OH)2.16
    EPMA (K0.96Na0.10)∑1.06(Al1.73Fe0.20)∑1.93(Al1.04 Si2.96)∑4O9.79(OH)2.22
    Formulas obtained by the two methods are in good. agreement with each other. The value for water content of 4.9 % given by ignition loss was agreement with that of 4.95 % given by EPMA. Small differences in the empirical formulas of several zeolites may be due to the reason that in the ICP analysis, the determined content of water is the average of the sample, while in the EPMA analysis, the value represents that of the micro area bombarded by electron.
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  • Yasuo IIDA, Masamichi FURUKAWA, Shozo SHIBATA
    1982 Volume 31 Issue 9 Pages T65-T70
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    A spectrophotometric titration system was constructed with Oki IF-800 personal computer and Shimadzu UV-360 spectrophotometer. For the the titration system, series of spectra of equilibrium solution were automatically introduced to the personal computer by using linear amplifier and digital input interface, and these data were stored in floppy disk file. The file was used to calculate the number of absorbing species by matrix rank analysis and to determine their specta and underlying equilibrium constants. The system avoids the error-prone manual handling of a large amount of data, and also it saves time and can overcome some difficulties in spectrophotometry, such as overlapping of the spectra of similar species. As an example, the acid dissociation equilibria of the six thiazolyl-azo-benzoic acid derivatives were studied by this spectrophotometric titration system. The compounds have similar spectra at neutral and anionic form. Under the condition of addition of cationic one at pH range 18, three species were recognized by matrix rank analysis with this system. The equilibrium constants and each spectrum were obtained by the modification of the Newton-Gauss non-linear least squares method.
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  • Masahiro TAKEUCHI
    1982 Volume 31 Issue 9 Pages T70-T74
    Published: September 05, 1982
    Released on J-STAGE: February 16, 2010
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    In order to expand linearly a dynamic range of response from a gas chromatography, the response of a constant-frequency electron capture detector was converted by an analog device, and the result was applied to a programmed temperature operation. The response showed the linear dynamic range of 103 or above by using pulses of the 2000 μs period. On the other hand, it was found that the ordinary ECD to be considered as a concentration-sensitive detector showed a function of mass-sensitive one according to the relation between the pulse period and the kind of electron capture reaction occuring within the cell. On supplying pulses of the 100μs period, the ECD acted as a concentration-sensitive detector for α-BHC, β-BHC, γ-BHC, δ-BHC, and p, p-DDE, and as a mass-sensitive one for p, p'-DDT. On supplying pulses of the 2000μs period, the ECD acted as a mass-sensitive one for all samples described above. Since it is preferable in programmed temperature operation that the ECD acts as a mass-sensitive detector in which the peak area of sample is independent of the flow-rate, the pulse of 2000μs period has been adopted for the present study. As the result, fairly good programmed temperature operation has been carried out.
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  • Yasuo TAKAHASHI
    1982 Volume 31 Issue 9 Pages T74-T79
    Published: September 05, 1982
    Released on J-STAGE: February 16, 2010
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    A method for analyzing aluminum and zirconium borides is presented. Decomposition of the borides was achieved in a Uniseal Decomposition Vessel (capacity, 23 ml), in which aluminum boride was heated with (1 + 1) HNO3 at 150°C for 3 h and zirconium boride with a mixture of (1 + 1) HNO3 and (1 + 5) H2SO4 at the same temperature for 6h. Aluminum and boron in the solution obtained were separated with cation exchange resin (Dowex 50 WX 8). Boron in the effluent was determined with the titrimetric method using mannite. Aluminum adsorped on the resin was eluted with 2 M HCl and determined by chelatometric titration. Zirconium was separated from boron as zirconium hydroxide by precipitation with NaOH and by filtration with a Nuclepore membrane filter. Boron in the filtrate was determined by the above mentioned method. After dissolution of zirconium hydroxide with HCl, zirconium was precipitated with mandelic acid.The optimum concentration of HCl for the complete precipitation of zirconium mandelate was (23) M. The precipitate was filtered on a G 4 glass filter, dried at 110°C and weighted as zirconium tetramandelate. The following boride samples were analyzed: Selected. crystals of α-AlB12 and β-AlB12, and two ZrB2 samples, the one prepared by carbothermic reduction and the other by direct reaction of zirconium and boron.
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  • Tokuo SHIMIZU, Hirotaka ARITA, Kaoru SAKAI
    1982 Volume 31 Issue 9 Pages E277-E284
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
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    To improve the sensitivity in the UHF plasma torch-atomic emission spectrometry (AES), and to reduce the matrix effects, the UHF power was increased from 0.5 to 1.0 kW. Optimum conditions of the sample introduction process were studied. For most of the elements, the relative net intensities of spectral lines increased with increasing UHF power, but the excitation temperature became lower. Since the gas temperature became higher with increasing UHF power, the matrix effects were slightly reduced. Detection limits for 13 elements were determined and compared with those of a conventional UHF plasma torch-AES.
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  • Kousaburo OHASHI, Sachiko IWAI, Masaru HORIGUCHI
    1982 Volume 31 Issue 9 Pages E285-E290
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The determination of cobalt(II) with 3-mercapto-1, 5-diphenyl formazan (dithizone) by a reversed-phase partition high performance liquid chromatography is described. Co(HDz)3 was separated from a mixture of Ni(HDz)2, Zn(HDz)2, Pb(HDz)2 and Cd(HDz)2 on a stainless steel column packed with Shimadzu Zorbax ODS by the use of methanol-water as a mobile phase. Co(HDz)3was first eluted to give a sharp elution peak, and the other complexes were eluted with almost the same retention time. The recommended procedure for the determination of cobalt(II) is as follows: A 10 ml of the sample solution containing cobalt(II), other metal ions and 100 mg of disodium tartrate should be shaken for 20 min with 10 ml of 5.00 × 10-3 mol dm-3 dithizone in chloroform at pH 8.5. An excess of dithizone in the extract can be removed by washing the extract with an ammonia-water mixture. A 10μl of the extract can be injected into the column by means of a micro syringe. Cobalt(II) can be determined in the range of 5.2 to 30.0 ng with the peak area calibration curve obtained at 550 nm in the presence of 24.2 ng nickel(II), 18.8 ng zinc(II), 52.6 ng lead(II) and 5.2 ng cadmium(II) using 85%(v/v) methanol-water at the flow rate of 1.0 ml/min within a relative error of + 4%. The analysis time was about 25 min.
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  • Tatsuya SEKINE, Kazuho INABA
    1982 Volume 31 Issue 9 Pages E291-E296
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Solvent extraction of iron(III) in aqueous sodium perchlorate solutions with trifluoroacetylacetone in carbon tetrachloride and the complex formation of the metal ion with this ligand in the aqueous phase have been measured at 298 K. It was found that the extraction was quantitative at lower pH than with acetylacetone and the rate is higher than with 2-thenoyltrifluoroacetone or benzoyltrifluoroacetone. These favorable properties of this extractant for iron(III) was concluded to be due to that it is rather water-soluble but still its tris-iron(III) complex is highly extractable.
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  • Sorin KIHARA, Zenko YOSHIDA, Taitiro FUJINAGA
    1982 Volume 31 Issue 9 Pages E297-E300
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The current-scan method has been found to be favourable in the voltammetric study on the ion transfer across the aqueous/organic solutions interface, and successfully applied to the polarography with the aqueous electrolyte dropping electrode. The advantages of the current-scan method over the potential-scan method are discussed. A simple device for the compensation of the ohmic potential drop is proposed.
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  • Taitiro FUJINAGA, Sorin KIHARA, Zenko YOSHIDA
    1982 Volume 31 Issue 9 Pages E301-E304
    Published: September 05, 1982
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The behavior of solute ions at the interface between aqueous and organic phases is clearly demonstrated by the current-scan polarography at the electrolyte dropping electrode. The potential-generating process at the liquid membrane type ion-selective electrode is explained on the basis of the polarographic results.
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