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Volume 7, Issue 7
Displaying 1-13 of 13 articles from this issue
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Hiroshi HAMAGUCHI, Rokuro KURODA, Shinya ENDO1958 Volume 7 Issue 7 Pages 409-415
Published: July 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSNitrate and nitrite coexisting with various nitrogen-containing compounds can be simultaneously. determined by the measurement of their ultraviolet absorption peaks at 302 and 355 mμ, respectively The simultaneous determination must be performed in the range from pH 5 to strong alkaline media, since the nitrite peak disappears and the unique peaks of nitrous acid begin to develop in acid media with pH values less than 5.
Conformity to Beer's law is observed in the range from zero to 15 mg of nitrate, and zero to 4 mg of nitrite per ml; Ringbom plots indicate that the optimum ranges are 2 to 7 mg of nitrate and 0, 4 to 2 mg of nitrite per ml.
The method is rapid and precise and does not involve any of the tedious problems associated with the previous methods of determination of nitrate and nitrite existing in nitrogen-containing compounds.View full abstractDownload PDF (1083K) -
Hiroshi HAMAGUCHI, Rokuro KURODA, Ryokichi NEGISHI1958 Volume 7 Issue 7 Pages 415-419
Published: July 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe purity of tungsten as a raw material in hard metal has much influence on the properties of the products, especially on their cutting efficiencies. Excitation of tungstate was made by an A. C. arc at 220 V and 7 A with a Littrow type quartz spectrograph. The emission spectrum of tungsten was very complicated, and it was ac companied by many difficulties in spectrochemical detection of impurities. An addition of graphite. powder caused a suppressive effect on the appearance of the tungsten spectrum and made it much simpler. The suppressive action on the appearance of the tungsten lines by the addition of graphite was attributed to the formation of high boiling tungsten metal and tungsten carbide. This fact was made clear by X-ray analysis of the residue after arc discharge. Addition of graphite caused also a weakening in the spectral lines of the impurities. Therefore, attempts were made to add the salts of Na, Ge, Ba, Tl etc., as a carrier for the impurities in order to prevent the lowering of the sensitivity of them by the distillation of the carrier. Among those, BaCl2: was the most effective as a spectroscopic carrier., Consequently, it was indicated that the impurities of tungstate could be easily detected without serious loss of sensitivities by addion of 5% BaCl2 and graphite powder 5 times the weight of the sample.View full abstractDownload PDF (884K) -
Mitsuru URA1958 Volume 7 Issue 7 Pages 420-424
Published: July 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSP in steels and special steels is converted into phosphomolybdic acid, and this is extracted with a mixed solvent composed of 2 volumes iso-butanol and 3 volumes chloroform for separation from interfering elements, and the P is then determined rapidly by estimating its light absorbency. The effect of the presence of Si, As, Cr, W, and V were investigated, and W and V were found to cause interference. However, that caused by the presence of V can be removed by its reduction treatment.
Analyses of a standard sample of carbon steel containing 0.025% P and of a standard sample of stainless steel containing 0.021% P were made, and the standard deviation of error was found to be 0.00037 and 0.00075, respectively. The time required for this method was 7?15 minutes, and the limit of estimation range was 0.003 0.8%.View full abstractDownload PDF (986K) -
Machio IWASAKI, Hiroshige MURAMATSU, Rimpei KOJIMA1958 Volume 7 Issue 7 Pages 425-429
Published: July 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIt is rather difficult to determine the p-and m-isomers of chlorobenzotrifiuoride by ordinary chemical analyses. In general, infrared spectro-photometry is the most suitable method for the determination of position isomers. Four methods of infrared analysis were applied to these compounds, and the results were tested by Youden's method. The key bands used were 9.84 and 12, 01 μ, in wavelengths for the p-isomer, and 11.26 and 12.28p, for the m-isomer. The absorbency was measured in CS2 solutions using cells of 0.1 mm thickness. The standard method and the ratio method were applied satisfactorily to mixtures containing the p-isomer in an amount 10?80%, standard deviations being 0.4?0.7%; while the base line method and the differential method were applied also satisfactorily to mixtures containing less than 10% of the p-isomer with standard deviations of 0.06?0.10%. It was found that the apparent extinction coefficient of the p-isomer is slightly affected by the concentration of the m-isomer in the solvent in the case of the base line and the differential methods.View full abstractDownload PDF (797K) -
Kazuo OTA1958 Volume 7 Issue 7 Pages 429-432
Published: July 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA direct method for determining Pb in free-cutting steel without preliminary separation of the Pb from the large amounts of Fe has been studied. Interference of Fe (III) is avoided by reduction with N2H4·2HCl and H·COONa, the latter also acting as the supporting electrolyte. Factors affecting the wave-height were investigated-that is, the amount of reagent, acidity, time of heating, interference of other metals, etc. -and as a result, the following procedure was established: a sample (2.5g) is dissolved in HCl (1+1, 30cc) and H2O2 (10%, 5cc) with gentle warming, heated to decompose the excess of H2O2, and diluted to 50cc. Ten cc is aliquoted into the measuringflask (50cc), then neutralized by dropping NH4OH (1+2) to a slight permanent precipitation, and clarified with HCl (1+1, 3cc). Then N2H4·2HCI (20%, 10cc), H·COONa (50%, 10cc), and starch (2%, 3cc)are added, in that order, and the mixture is heated over a boiling water bath for 5 minutes. After cooling and diluting to the mark, Pb is then polarographically determined in the usual way. Cu(0.4%), As(0. 1%), Sn(0.05%), Cr(2%), Mo(0.1%), and the other elements encountered in the analysis of ordinary free-cutting steel do not interfere.View full abstractDownload PDF (714K) -
Noboru YAMAGATA, Toshiko YAMAGATA, Shunji MATSUDA, Eisaku TAJIMA, Sada ...1958 Volume 7 Issue 7 Pages 433-438
Published: July 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe separation of mixed alkali chlorides from the hydrochloric acid extract of sample ash was performed by the usual method after the addition of about 20mg of cesium carrier. Precipitation of sulfate ion with barium chloride solution was presumed to carry down radium activity which might be coexisting with Cs-137. The precipitates of hydroxide, carbonate, and oxalate were also considered to carry the activities of Sr- 90 and rare-earth elements. The loss of cesium in the whole process was proved to be very small. Other than the Cs activity, the mixed alkali chlorides contained the natural activities of K-40 and Rb-87. The alkali chlorides from the usual crop samples, 10?50g, contained about 104 dpm of K-40, several hundred dpm of Rb-87 and about the same amount of Cs-137. As the radio assay was performed by β-counting using a GM-tube of the mica end-window type, the separation of Cs from Rb, and especially from K, was needed. The separation was effectively undertaken by the chloroplatinate precipitation method in aqueous solution after the preliminary separation of the sodium chloride and a part of the potassium chloride by the hydrochloric acid ethyl alcohol method. The final precipitate of cesium chloroplatinate was weighed and mounted for counting. About several hundred dpm or 1030 cpm of Cs-137 activity was measured with each sample, and the result was corrected for the chemical yield of cesium.View full abstractDownload PDF (1113K) -
Studies on the separation of fission products by the distillation method. IVTomihisa KAMBARA1958 Volume 7 Issue 7 Pages 439-441
Published: July 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe distillation of carrier-free ruthenium to isolate it from mixed fission products has been carried out using lead peroxide in sulfuric acid solution. The yield of distillation by this method is higher than that by any other method studied. The decontamination factor is 2×105. The time for distillation is about 15 minutes. The characteristics of this method are discussed.View full abstractDownload PDF (553K) -
Shinnosuke HIGASHI1958 Volume 7 Issue 7 Pages 441-444
Published: July 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA colorimetric method was adopted for determination of the microgram amount of thorium in some organisms. The thorium contents in these samples were estimated as following values.
Plant ashes: 15μg/g, Duckweed ashes: 34μg/g, Seaweed ashes: 0. 30. 6μg/g, Shells and Corals 0.070.8μg /g.View full abstractDownload PDF (879K) -
Chozo YOSHIMURA, Mitsuo KIBOKU1958 Volume 7 Issue 7 Pages 445-449
Published: July 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSIt is known that various metal ions form a precipitate with tannic acid, but the pH ranges for their complete precipitation are not clear. This report deals with the formation of pH curves for precipitation of iron and titanium groups by tannic acid, and the pH ranges for their complete precipitation have been determined. Studies have been also made on the effect of pH and masking agent for their mutual separation. The results indicated that the pH ranges for their complete precipitation are as follows : Fe2+ 4.6?7.8, Fe3+4.5?10.6, Co2+ 8.3?9.3, Ni2+ 7.5?9.0, Mn2+ 8.3?10.3. By utilizing the differences in pH for their complete precipitation, separatory determinations of Fe3+-Mn2+, Fe3+-Co2+, and Fe3+-Ni2+ were made; also, separatory determination of Fe2+-Fe3+- was made by the use of tannic acid and EDTA. In the titanium group, the pH for complete precipitation with the use of NH4Cl buffer solution was as follows: Ti4+ 2.0?9. 5, Zn4+ 2.0?10.4, Hf4+ 4.5?9.6, Th4+ 3.9?4.1. The pH values with the addition of citric acid to these were : Ti4+5.0?8.8, Zr4+ 6.1?10.4, Hf4+ 6.2?11.2, and Th4+ 7.9?10.1 and those with the addition of NH4HF2 were : Ti4+ 8.5?9.8, Zr4+ 7.4?11.4, Hf4+ 7.3?10.2, and Th4+ 8.2?9.4. By utilizing the solubility of the precipitate of metal tannate in hydrogen peroxide, separatory determinations of Ti4+-Zr4+, Ti4+-Hf4+, and Ti4+-Th4+ were carried out.View full abstractDownload PDF (886K) -
Mariko INARIDA1958 Volume 7 Issue 7 Pages 449-451
Published: July 05, 1958
Released on J-STAGE: May 07, 2010
JOURNAL FREE ACCESSAs a method for the mutual separation of Te(IV)and Te(VI), separation by precipitation with sulfur dioxide gas, by precipitation at pH 4.2 and by the use of anion exchange resin have been used. In order to make a more rapid and simpler separation than by these methods, the author had already tried separating them by extraction with TBP(20%), and good results were obtained. This time, separation of Te(IV) and Te(VI) by extraction with TBP(100%) was tested. Quantitative extraction of Te(IV) by TBP (100%) in 210N HCI (Table 1) was possible Te(VI) remaining unextracte in aqueous solution (Table 2). Thus with 100% TBP, the quantitative separation of these two ions was possible in 210N HClView full abstractDownload PDF (564K) -
[in Japanese]1958 Volume 7 Issue 7 Pages 452-458
Published: July 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (1509K) -
[in Japanese], [in Japanese]1958 Volume 7 Issue 7 Pages 459-465
Published: July 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (1279K) -
[in Japanese]1958 Volume 7 Issue 7 Pages 466-467
Published: July 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESS
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