Search

Your search keyword '"Yoshimori, Takayoshi"' showing total 103 results
Start Over Author "Yoshimori, Takayoshi"
103 results on '"Yoshimori, Takayoshi"'

5. Determination of Microamounts of Carbon in Metals by Wet Chemical Oxidation and Nonaqueous Coulometric Titration

Author

Kutsumi, Hiroyuki, Yoshimori, Takayoshi, and Tanaka, Tatsuhiko

Abstract

A method for the determination of microamounts of carbon in metals which do not achieve complete combustion has been developed. This method is based on wet chemical dissolution with a mixture of 280ml of 5 to 10M sulfuric acid and 16 g of potassium dichromate, with and without the addition of a small amount of copper(II) sulfate in a stream of oxygen, and on nonaqueous coulometric photometric titration of the evolved carbon dioxide. The reagents used for the wet chemical method were highly purified in order to lower the blank value. Microamounts of carbon In sucrose could be determined with good precision and accuracy. Trace amounts of carbon (0.8–166 ppm) in iron, low-carbon steels, titanium alloy, indium and gallium were determined precisely and accurately. The blank value and determination limit obtained by the proposed method are lower than those previously obtained by wet chemical dissolution and volumetric titrimetry.

Published
1989
Full Text
View/download PDF

6. The Precise Coulometric Titration of the Acidic Primary Standard using Amperometric End-point Detection

Author

Yoshimori, Takayoshi and Matsubara, Ikuko

Abstract

The sensitive amperometric end-point procedure (Anal. Chem., 23, 1662 (1951)) with an antimony electrode is used in the titrations of acids. The cyclic voltammetric curves of the electrode indicate the possibility of the use of the above method for the titration of acids. The purities of potassium biphthalates (primary standard substances) are determined directly by precise coulometric titration with this end-point location. The standard deviations of the results (99.999%) are 0.007 or 0.008%. The purity of the benzoic acid prepared as the standard material for the calorimeter is also determined by this method. The standard deviation of these results (99.993%) is 0.009%.

Published
1970
Full Text
View/download PDF

7. Coulometric Titration of a Microamount of Water after Conversion to Ammonia

Author

Yoshimori, Takayoshi and Ishiwari, Syuiti

Abstract

Sodium amide was used to convert a microamount of water into ammonia in a carrier gas. The ammonia was then titrated with coulometrically generated hypobromite ions. The reaction between water and sodium amide was completed stoichiometrically, and the reaction rate was considerably promoted by heating sodium amide at 80°C. The sample hydrogen was oxidized with copper(II) oxide at 800°C, and the water thus produced was determined by this method. 0.096–0.665 ml(8.6–59.8 μg) of hydrogen and 0.055–0.465 mg of water in barium chloride crystals were determined within errors of 3.6% and 3.0% respectively. The water adsorbed on the surfaces of the weights was also determined by this method at various humidities.

Published
1969
Full Text
View/download PDF

8. The Determination of Tin in Tin Metal and in Zircaloy by Precise Coulometric Titration

Author

Yoshimori, Takayoshi, Matsubara, Ikuko, Tanaka, Tatsuhiko, Yoshida, Kazuo, Tanaka, Kazuo, and Tanabe, Toyokazu

Abstract

The purities of tin metals are determined directly by precise coulometric titration. The sample is dissolved with hydrochloric acid in a nitrogen atmosphere. The solution is then introduced into a hot antimony column. The reduced tin(II) ions are titrated with electrolytically-generated iodine. The titration is accomplished in a special cell by the use of which any disturbance of atmospheric oxygen is avoided. The titration efficiency under these acidic media was decreased when the current density was increased more than several mA/cm2. The results obtained by two different analysts for the sample of the pure tin metal (5-nine) were 99.996 and 99.991%. The standard deviations of the results were 0.025 and 0.016% respectively. The tin in the other tin metals and in Zircaloy samples was determined satisfactorily without the use of any experimental factor.

Published
1971
Full Text
View/download PDF

12. NIPPON KAGAKU KAISHI

Author

YOSHIMORI, Takayoshi, primary, TANAKA, Tatsuhiko, additional, HOSHINO, Toshibumi, additional, and HASEGAWA, Kenji, additional

Published
1981
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results