BUNSEKI KAGAKU
Print ISSN : 0525-1931
Volume 8, Issue 8
Displaying 1-11 of 11 articles from this issue
  • Studies on electroanalysis by the use of EDTA. IVV
    Hisao HAYAKAWA
    1959 Volume 8 Issue 8 Pages 487-491
    Published: August 05, 1959
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    Conditions for the electrolytic determination of silver and mercury, and the method of electrolytic separation of each metal from copper have been studied in the case of the procedure employing EDTA.
    As for silver, the following conditions are suitable for its determination: the pH of the solution, containing twice as much EDTA in molar ratio as silver, is adjusted to 910 with aqueous sodium hydroxide, and the solution is electrolyzed at a bath voltage of 1.22V and at a temperature of 50°C or thereabout. Silver, less than 108mg, can be quantitatively determined as a very lustrous deposit, but if its amout is 160mg or more, accurate results are not obtained. By this method, its quantitative separation can be made in the presence of more than 600 mg of copper.
    As for mercury, it was proved that a very beautiful deposit can be obtained even in the absence of depolarizer. The platinum cathode must be plated with silver before use. If the pH of the solution, containing 34 times as much EDTA in molar ratio as mercury, is adjusted to 35 with sodium carbonate solution, and the solution is electrolyzed at a bath voltage of 23 V at room temperature, 60120 mg mercury can be quantitatively determined as a lustrous deposit. After electrolysis, the cathode is washed with water, acetone, and ether in sequence, then dried with an electric fan. Coexisting copper, less than 150mg, does no harm, but if its amount is over 190mg, a positive error results.
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  • Yoshihide ENDO, Hajime TAKAGI
    1959 Volume 8 Issue 8 Pages 491-495
    Published: August 05, 1959
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The quantitative determination of Al3+ and Fe3+ in Cr-brick and Cr-ore containing large amounts of Cr3+ by the use of oxine (8-hydroxy-quinoline), EDTA (disodium ethylenediaminetetraacetate) and CyDTA (cyclohexanediaminetetraacetic acid) has been investigated.
    The sample after fusion with potassium acid sulfate is oxidized with HNO3, an amount of EDTA excess of that required for the equivalent weight of Fe3+, Al3+, Cr3+, Ca2+, and Mg2+ is added, and the solution at pH 46 is boiled for the formation of complex salts of Fe3+, Al3+, and Cr3+, and EDTA. It is then treated with oxine, made alkaline with ammonia, heated at about 80°C for precipitation of Fe3+ and Al3+, and allowed to stand for 10 min. for aging. The precipitate of oxinate is filtered off, taken up in. HCl; and the Fe3+ at pH 22.2 is titrated with EDTA using the liberated oxine as an indicator. The solution is then heated to boiling and Al3+ is titrated at pH 22.2 with CyDTA using Cu2+-PAN (Cu2+-α-pyridyl-β-azonaphthol) as an indicator. The results indicated that the masking of Cr3+ by EDTA is complete, and that oxine is sensitive as the indicator in the chelate titration of Fe3+, and that the presence of oxine is without influence in the determination of Al3+. The accuracy and rapidity for practical operation_ were proved to be entirely satisfactory.
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  • Sizoo HIRANO, Hiroo SASUGA
    1959 Volume 8 Issue 8 Pages 495-500
    Published: August 05, 1959
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    It is difficult to determine magnetite in sulfide ores by the usual method of chemical analysis. A structure analysis of Yanahara and Kune of copper-containing pyrite by the use of an X-ray diffractometer has been made by the authors, and the quantitative determination of magnetite, pyrite, and chalcopyrite by the use of an X-ray diffractometer has been investigated. By using X-rays from the Kα-ray of Co, and with sodium_chloride as an internal standard, a simultaneous determination of magnetite, pyrite, and chalcopyrite was carried out. The particle size of the sample was studied by the use of an electron-microscope, and it was found that pulverization to several microns size was sufficient for magnetite and chalcopyrite; but pyrite at this size showed a poor reproducibility, and it was necessary to be pulverized to below 0.x micron.The reproducibilities were ±5%, and the results showed good agreement with those of chemical analysis and with values estimated from magnetic separation.
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  • Studies on controlled potential electroanalysis. VIII
    Masao TANAKA
    1959 Volume 8 Issue 8 Pages 501-508
    Published: August 05, 1959
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Deposition potentials of metals, such as gold, silver, mercury, copper, bismuth, lead, cadmium, and antimony, in various supporting electrolytes, such as ammonium nitrate-EDTA, ammonium acetate-EDTA, and ammonia-ammonium chloride-EDTA, have been measured, and the problem of quantitative deposition of these metals has been investigated. The results showed that the depositions of copper, cadmium, and silver, were quantitative, but the states of electrodeposition of the other metals were not so good.
    Also, it was confirmed that electrolysis with the use of EDTA supporting electrolyte caused an inclusion of EDTA in the metal deposited on the cathode, and exhibited a tendency to give a plus error.
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  • Studies on controlled potential electroanalysis. IX
    Masao TANAKA
    1959 Volume 8 Issue 8 Pages 508-513
    Published: August 05, 1959
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The principal components of copper-zinc alloy have been investigated by means of a successive electrolytic analysis by the limited cathode potential method. Copper alloys containing few impurities were dissolved in nitric acid, and the solution was evaporated to dryness after the addition of sulfuric acid. It was found that the electrolytic determination was possible by using this limited cathode potential method with a platinum electrode and one of the following supporting electrolytes:
    (1) The cathode potential is limited to -0.20 V vs. S. C. E. with the use of 0.4N sulfuric acid for electrolytic determination of copper. The residual electrolyte is neutralized with ammonia; then ammonia is added in excess to 1.2N, in which electrolytic determination of zinc is made by using a copper-plated platinum electrode at a limited cathode potential of -1.40 Vvs. S. C. E..
    (2) The copper is determined in a solution containing 0.4M sodium tartrate and 0.1M sodium acid tartrate at a limited cathode potential of-0.50V vs. S. C. E., then electrolytic determination of zinc is carried out at a limited cathode potential of -1.20 V vs. S. C. E...
    (3) The copper is determined in a solution containing 1.2N ammonia and 0.46M ammonium chloride at a limited cathode potential of -0.60 V vs. S. C. E.; then the zinc is determined under a limited cathode potential of -1.50 V vs. S. C. E...
    In the case of nickel-copper alloy, the sample is dissolved in nitric acid, evaporated to dryness after addition of sulfuric acid; and the residue is dissolved in water, and the copper is determined in an electrolyte containing 1.2N ammonia and 0.2M ammonium sulfate under a limited cathode potential of -0.60 V vs. S. C. E.. Then the nickel is determined under a limited cathode potential of -1.15 V vs. S. C. E. at 60°C. Good results were obtained.
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  • Yuroku YAMAMOTO
    1959 Volume 8 Issue 8 Pages 513-518
    Published: August 05, 1959
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    This report deals with the results of an investigation of the ultraviolet spectrophotometric determination of bismuth using perchloric acid as a reagent.
    Absorption spectra of bismuth perchlorate under various concentrations of perchloric acid were obtained, and it was observed that the bismuth ion (hydrated) showed the maximum absorbance at 222 mμ (Fig. 1). Absorption spectra of bismuth salts in weak acidic medium (pH 13) were also measured, and it was observed that two isosbestic points exist; and it was presumed that the change of spectra with pH may be attributed to the change of equilibrium between bismuth aquo ion and hydroxo complex ion (Fig. 2 and 3). In the spectrophotometric determination, the calibration curves were made by the usual and by the differential method; and then the effects of the temperature and diverse ions were investigated. The following results were obtained:
    1. The use of a wave length of 222mμ and a 1.0N perchloric acid was chosen as the working conditions.
    2. Beer's law is followed up to 15 ppm by the usual method, and up to 70 ppm by the differential method. The errors in these were found to be 0.110.18% (Fig. 4 and 5).
    3. The temperature coefficient of absorbance was 0.0009/°C.
    4. The presence of iron(III) gave a considerable positive error.
    5. It was found that the specific absorption spectrum appeared when aluminum ion was present with bismuth, and it was presumed that a specific interaction occurs between the two ions in the perchloric acid medium (Fig. 6).
    Thus, the proposed method has the features of not requiring a special coloring reagent as in the organic one, besides having the merits of simplicity of operation and of giving good accuracy of results.
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  • X-ray fluorescence spectrometric analysis using G. E X-ray fluorescence spectrometer. I
    Hidehiro GOTÔ, Sigeyosi IKEDA, Emiko SUDÔ
    1959 Volume 8 Issue 8 Pages 518-522
    Published: August 05, 1959
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    Although X-ray fluorescence spectrometric analysis is one of the most simple and rapid methods because of its non-destructive and nonseparative procedure for sample treatment, it required various calibrations for the phenomena. accompanying X-ray excitation of elements.
    In the present research, using a G. E. X-ray fluorescence spectrometer, fundamental studies were carried out on the X-ray fluorescence radiation of Cu in Al-Cu alloy, a simple alloy which would not be expected to have any resonance excitation or absorption of X-ray mutually between the components; and of Ag in Ag-Al alloy, which has a comparatively low X-ray radiation efficiency.
    The radiation intensity of the CuKα and CuKβ line revealed proportionality with the Cu content of the Cu-Al alloy. The Ag Kα intensity was also proportional to the Ag % in the Ag-Al alloy.
    The relation between the radiation intensity of the Cu Kα line or the Ag Kα line and the voltage or current of the primary X-ray power source were also investigated.
    In the powdered sample of Al-Cu alloy, the same CuKα intensity as that of the plate specimen sample was obtained when the powder was finer than 200 mesh.
    Applying these results, an analysis of the segregation of Cu in a cylindrical sample of Al Cu alloy was made.
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  • Koichi MUKAI, Koichi GOTO
    1959 Volume 8 Issue 8 Pages 523-526
    Published: August 05, 1959
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    Aluminum and fluorine form a stable complexion, and it has been considered that the quantitative determination of either of these elements from their solution is interfered by the other.
    However, a rapid determination of the two elements is possible by the use of the following procedure:
    A sample solution containing 515 mg aluminum and 0400 mg of fluoride ions is prepared.
    It is made up to about 150 ml with water; 10 ml of 5% oxine solution of acetic acid acidity is added, and then sodium hydroxide is added to above pH 12. Acetic acid is added to pH 10, and the mixture is heated at 70°C. The precipitate is filtered off, washed, and dried for determination of aluminum.
    The filtrate is made up to a definite volume, a portion equivalent to about 10mg fluorine is adjusted to pH 59, and the excess of oxine is removed by extraction with chloroform. The solution is then made up to 150 ml, and adjusted to pH 3, and the fluorine is determined by the usual method of titration with thorium nitrate.
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  • Kenji MOTOJIMA, Hiroshi HASHITANI
    1959 Volume 8 Issue 8 Pages 526-531
    Published: August 05, 1959
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    In the work reported by Darbey, the sample was treated with hot dilute hydrochloric acid to leach the contained oxine. Then, the color intensity of the solution was measured at 365 mμ. However, this method is seriously affected by iron and also by some organic substances, which show appreciable absorption at 365 mμ.
    In the present method recommended by the authors, the sample is treated with phosphoric acid in order to eliminate the absorption of iron (Fig. 1-(3)), and the absorbancy of the solution is directly measured at 360 mμ (1st procedure). When colored organic materials are present in the sample, the following method is recommended (2nd procedure). The acid solution (oxine<1.5 mg) is treated with copper sulfate solution, and the pH is adjusted to about 5. Then the extraction is made with a definite volume of chloroform, and the absorbancy of the extract is measured at 410 mμ. Oxine is determined by the use of a prepared calibration curve.
    On the other hand, copper is estimated with oxine by the extraction-differential photometric method: oxinates of copper and other materials contained in the sample are simultaneously extracted with a definite volume of chloroform. Then the extracted chloroform solution is divided into two fractions. One fraction is washed with about 10 ml of potassium cyanide solution (pH 89, saturated with chloroform) to remove the copper. The absorbancy of the other fraction is measured at 410 mμ using this washed one as reference. Copper is determined by the use of a prepared calibration curve.
    Very satisfactory results were obtained with this method.
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  • Seiichiro HIKIME, Hitoshi YOSHIDA, Yasumitsu UZUMASA
    1959 Volume 8 Issue 8 Pages 531-535
    Published: August 05, 1959
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    In the analysis of steel it is of course necessary to separate iron from the other elements. As one of the investigations for this purpose, the authors have studied the separation of Fe(III) from Te (IV) in hydrochloric acid solution by means of extraction methods using 100% n-tributylphosphate (TBP).
    When the acid concentration of the solution is lower than 0.1N, neither Fe nor Te is extracted by TBP, but with increasing concentration of hydrochloric acid Fe as well as Te are extrated into the TBP-phase. In the presence of potassium thiocyanate in the solution, however, Fe is nearly completely extracted into the TBP-phase as thiocyanate, while Te is extracted only partially (pH 0.4, ca. 5%; pH 1.0, ca. 20%). A little Te thus extracted can then be extracted back to the aqueous phase by shaking the TBP-phase with 0.1N hydrochloric acid solution. Ten ml of TBP is added to 10 ml of the hydrochloric acid solution, containing 250350 γ Te, 0.3535 mg Fe and 500 mg KSCN, and after adjusting the pH to 0.4, the mixture is shaken for 2 minutes. The TBP-phase is then separated and shaken with 10 ml of 0.1N hydrochloric acid solution for 1 minute. By this procedure the Te which escaped from the aqueous solution to the TBP-phase is extracted back into the former. This aqueous solution is combined with the original aqueous phase, and centrifuged. Te together with a small amount of Fe which remains in the aqueous phase are determined photometrically.
    The results are as follows: Te in aq. phase ca. 99%, Fe in TBP-phase ca. 99.9%.
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  • [in Japanese]
    1959 Volume 8 Issue 8 Pages 536-542
    Published: August 05, 1959
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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