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Volume 7, Issue 5
Displaying 1-13 of 13 articles from this issue
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Satoyoshi OZAKI1958 Volume 7 Issue 5 Pages 275-283
Published: May 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe determination of small quantity of phenols has been important, not only in some chemical industries such as the high-polymer industry, but also to the industrial waste-water problem. Considerable researches have been carried out in nephelometry and various photometric methods.
The author has taken three methods, i. e. the p-nitroaniline, the nitronizing, and the 4-aminoantipyrin methods, for a comparative study of their application to colorimetric analysis. The results showed that the 4-amino method is most fitted for use particularly in the case of 2 ppm or less phenol content, and the nitronizing method for the analysis of phenol mixtures, while the nitroaniline method has an advantage in its simplicity of operation. However, with respect to both precision and speed of operation, the 4-amino method seems to be the one best suited for the determination of small amounts of phenols in water.View full abstractDownload PDF (1609K) -
Hiroshi KITAGAWA, Norio SHIBATA1958 Volume 7 Issue 5 Pages 284-287
Published: May 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe spectrophotometric determination of nickel extracting the dimethylglyoximate with chloroform has been investigated and the following facts were found: (1) Suitable pH range for the extracting of nickel dimethylglyoximate was 59. (2) The optimum wave length for photometric determination was found to be 370380 mμ. (3) The chloroform solution containing the extract was very stable. (4) The effects of the presence of other elements have been investigated and found that the presence of above 0.2 mg copper, above 5mg cobalt, above 20mg chromium, and above 100 mg manganese against 0.20 mg nickel showed disturbing influence for the determination, while there were practically no influence in the presence of 500mg each of aluminum, bismuth, cadmium, iron, molybdenum, zinc, tin, antimony, titanium, vanadium, and tungsten. (5) The disturbing effect of copper was decreased by treating the extract with ammonium acetate-ammoniac solution containing dimethylglyoxime. There was also given a method which can be applied for the determination of nickel in ferrous and nonferrous metals.View full abstractDownload PDF (780K) -
Genzo HASHIZUME, Yuzi HAGINO, Masamitu KOBAYASHI1958 Volume 7 Issue 5 Pages 287-292
Published: May 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSInas much as the application of chemical analysis to condensed phosphates is difficult, a study has been made of the possible application of an X-ray diffractometer to the quantitative analysis of condensed phosphate (NaPO3-Na5P3O10 system), which generally contains an amorphous part.
In such condensed phosphates, the amorphous part is easily transformed to a mixture of crystalline NaPO3 and Na5P3O10 by heat treatment at an adequate temperature. It is then possible to infer or deduce various characteristics of the original sample (before the heat treatment); and there-by to control the quality of industrial products by means of the analysis of the composition of the crystalline mixture obtained by the heat treatment.
NaPO3 (I) and Na5P3O10 (I) were employed as the crystal forms for the analysis because they are more stable; and their treatment is easier, and their diffraction intensity is stronger than those of any other crystal form. The sample was heated at 500550°C. CaSO4·1/2 H2O was used as the internal standard.
As a result of an examination of the heating time, it was seen that the transformation to NaPO3 (I) is rapid, so that accurate results can be produced by heating 1 hr. at 500°C; while to be sufficiently transformed to Na5P3O10 (I) it is necessary that the sample be heated more than 2 hrs. at the same temperature. The smaller its content is, the longer the sample should be heated.
The average deviation of the experimental results was of the order of 5%. Several samples (both commercial and laboratory) were investigated, and some interesting facts were obtained.View full abstractDownload PDF (1264K) -
Masanobu SAKANOUE1958 Volume 7 Issue 5 Pages 292-296
Published: May 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe simple determination of uranium by paper-chromatography has been improved with respect to its reproducibility and sensitivity. Uranium, extracted by ethyl acetate and moved upward on a paper strip (1cm×40cm), reacted at the front line of a 30% potassium ferrocyanide solution which had been previously soaked into the paper strip at a definite position. The brown-colored uranium ferrocyanide line was obtained. The paper strips with these colored lines could be washed in running water without apparent decoloration of the lines. They were then soaked in fused paraffin, and compared with those of a standard series.
These lines could be obtained with good reproducibility, and could be kept without undergoing change for several months. By this method, as little as 0. 02 μg uranium on the paper strip gave a detectable line. For geochemical research, this method was applied to the determination of uranium in solid samples and in water.View full abstractDownload PDF (1035K) -
Studies on the continuous coulometric titrator. IIITakeo TAKAHASHI, Hiroshi SAKURAI1958 Volume 7 Issue 5 Pages 296-300
Published: May 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSWhen the amperometric titration method is used for end-point detection in the continuous coulometric titration, a linear titration curve is obtained, showing that the relationship between the concentration of sample and the electrolytic current is linear, even if the power source for electrolysis is obtained from the out-put of a D. C. amplifier.
Also the voltage sensitivity at the working point does not depend upon the concentration of the component to be determined in the sample solution. This fact is very fortunate in the examination of the transition phenomena of the titrator. As the indicator current is converted into voltage by means of passing through resistance, any sensitivity of voltage (the slope of the titration curve) can be easily selected by changing the value of resistance.
In the present paper the principle of continuous coulometric titration with amperometric end-point detection is considered theoretically, and the differences between this method and that with potentiometric end-point detection is discussed.
As an experiment a dilute solution of arsenous acid is continuously titrated, and recorded with coulornetrically generated bromine. The linearity between the concentration of arsenous acid and the electrolytic current is better than that obtained by the method with potentiometric end-point detection, so that its reproducibility of results is good.View full abstractDownload PDF (929K) -
Saburo YANAGISAWA, Michiharu SEKI, Yoshikazu WATANABE, Shigeru NAKAMUR ...1958 Volume 7 Issue 5 Pages 301-304
Published: May 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe authors have improved the thermal conductivity method which had hitherto been able to analyse low contents of heavy water up to 0.1%. The heavy water is changed by a heated zinc and platinum catalyser into hydrogen and hydrogendeuterium gases, and their thermal conductance is measured by a wheatstone bridge. The characteristics of this method are that the apparatus is simple in construction, a thermistor is used as the resistor in the cell, and the pressure is measured at 0°C at about 150 mmHg. The lower limit is 0.05%, and a precision of ±0.02% can be attained by this method.View full abstractDownload PDF (711K) -
Studies on the determination of nitrogen in nitrocellulose and nitric acid. ITetsuro MURAKAMI1958 Volume 7 Issue 5 Pages 304-309
Published: May 05, 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSNitrogen in nitrocellulose and in nitric acid in a sulfuric acid-nitric acid mixture can be determined rapidly and accurately by an acidimetric titration method. The sample is boiled with 20 g ferrous sulfate acid'fied with 6?8N hydrochloric acid in argon gas, resulting in the formation of nitrogen oxide. The nitrogen oxide gas is washed with sodium hydroxide solution, then oxidized to nitric acid by the use of oxygen and hydrogen peroxide, and titrated with a standard sodium hydroxide solution.
Application of this method to the determination of nitrogen in nitrocellulose causes complete decomposition in a short time and quantitative determination can be made within 30?40 minutes with a standard deviation of error of 0.02%.
The determination of nitric acid in a sulfuric acid-nitric acid mixture can be made accurately without any effect of sulfuric acid.View full abstractDownload PDF (1329K) -
Shigeo WAKAMATSU1958 Volume 7 Issue 5 Pages 309-313
Published: May 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIt has been said that the boric acid in an acid solution is volafized easily. The following experiments have been carried out in order to investigate this contention.
In the determination of boron in steel, one part of the sample was decomposed with a reflux condenser attached as in the usual method in order to avoid the loss of boron by volatilization, while the other part was heated in a beaker without the equipment for recovering volatilized boron. The results showed that there was no difference in analytical values, as indicated in Table 2.
Also, boron could not be detected in the vapor evolved during the decomposition, as indicated in Table 1.
There was no evidence of volatilization of boron during the concentration of boron-containing sulfuric acid, hydrochloric acid, and aqua regia, as indicated in Table 3. However, the use of acids other than sulfuric acid gave lower values when these were evaporated to dryness, as shown in table 4. A lower value was also obtained even with the use of sulfuric acid when heated for too long a time at the white-fuming temperature, as shown in table 5. Various investigations revealed that this was not caused by the volatilization of boron, but rather by the formation of a compound which does not react with the boron coloration reagent, this formation resulting from evaporating to dryness or from heating at the whitefuming temperature with sulfuric acid.
Accordingly, in the determination of boron in a boron-containing acid solution, there is no danger of loss of boron by volatilization unless the solution is evaporated to dryness, or heaed at the whitefuming temperature with sulfuric acid. The use of a reflux condenser during the decomposition of the sample is unnecessary.View full abstractDownload PDF (959K) -
1958 Volume 7 Issue 5 Pages 319a
Published: 1958
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSDownload PDF (158K) -
1958 Volume 7 Issue 5 Pages 319b
Published: 1958
Released on J-STAGE: February 16, 2010
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[in Japanese]1958 Volume 7 Issue 5 Pages 320-333
Published: May 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESS -
1958 Volume 7 Issue 5 Pages 333
Published: 1958
Released on J-STAGE: May 07, 2010
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[in Japanese]1958 Volume 7 Issue 5 Pages 334-336
Published: May 05, 1958
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESS
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