All issues
Volume 9, Issue 11
Displaying 1-14 of 14 articles from this issue
- |<
- <
- 1
- >
- >|
-
Studies on automatic continuous coulometric titration. VIIAkira TAKAHASHI1960 Volume 9 Issue 11 Pages 921-925
Published: November 05, 1960
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe alkalinity of water, which is one of the important factors to be measured in the water cleaning treatment, was continuously determined by the method of an automatic continuous coulometric titration.
The sample water and the electrolyte solution (ca. 0.15M sodium sulfate), both of which were poured into the the titration cell with a constant flow rate, were mixed each other, and the alkaline constituent contained in the sample water was titrated with the hydrogen ion generated by electrolytic oxidation of said Na2SO4 solution_ The glass electrode (pH of the inner solution= 2) and the saturated calomel electrode were used as detecting electrodes, and the commanded. voltage was not selected at-300 mV (corresponding to pH 7) but at -215 mV (vs. S. C. E.) based on the data obtained experimentally for the purpose of determination of total alkali.
The alkalinities of several sample solutions prepared with NaOH and Na2CO3 were measured, and successful results were obtained in relationship between the electrolysis current and the alkalinity, with good reproducibility of measurement and with high stability of recording.View full abstractDownload PDF (835K) -
Studies on the analytical methods of trace impurities in high purity substances. IVMasuo MIYAMOTO1960 Volume 9 Issue 11 Pages 925-929
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSChemical analysis of Pt and Pd in high purity gold was studied, whereby the separation and the successive determination of the two have been successfully achieved.
Sample is decomposed by aqua regia and dissolved in hydrobromic acid solution. Then Au is removed almost completely by repeated isopropylether extraction. From the remaining aqueous solution, Pd is extracted by dimethylglyoxime-chloroform method, and determined spectrophotometrically using reagent PAN (α-pyridyl-β-azonaphtol). From the residue, Pt is, determined also spectrophotometrically by the dithizone method.
These two determination procedures being new, its analytical conditions were examined. The method is rapid and very sensitive. Each content as low as 0.2 ppm is readily determined from 1g sample and the whole operation may be achieved in about 5 hours.View full abstractDownload PDF (770K) -
Toru NOZAKI, Hirondo KURIHARA1960 Volume 9 Issue 11 Pages 930-933
Published: November 05, 1960
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSCoprecipitation of Fe3+, Al3+, Cr3+, Co2+, Mn2+, Mg2+ and Na + with the calcium oxalate precipitated from homogeneous solution using urea hydrolysis was studied. The solutions were prepared as to contain 9.55 mg of Ca, varying quantities of metallic ions and ammonium oxalate, 3ml of 3N HClO4 and 1.5g of urea, the final volume being adjusted to 50 ml. In the course of precipitation, the coprecipitated amount increased with the percentage of Ca precipitated up to 95%, and beyond this percentage the amount decreased a little. As the excess of oxalate ion for calcium increased, the amount of iron (III) coprecipitated decreased rapidly until the molar ratio of excess oxalate to iron (III) came to 5. After the ratio increased beyond 5, the coprecipitated amount of iron(III) approached a constant value. The order of the coprecipitated amount of the metals having a property to form oxalate complexes accorded with the order of instability constant of each complex. The amounts coprecipitated with the change of concentration of metallic ions were measured.View full abstractDownload PDF (747K) -
Yohe TSUCHIYA1960 Volume 9 Issue 11 Pages 934-939
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSBeryllium forms a red complex with aluminon in a faintly acidic solution, the absorption maximum of the complex lying at near 540 mμ. It is found that the reaction itself and also the masking of interfering ions with EDTA had better be accelerated by heating of the solution and that the sensitivity becomes greater in sodium acetate buffer than in ammonium acetate buffer, the optimum pH for the reaction being dependent on concentration of aluminon or on presence of gelatin. Absorbancy increases with increasing concentration of aluminon and in presence of gelatin, but decreases with increasing concentrations of EDTA and ammonium or alkali metal ions. And the effect of alkali metal ions on the absorbancy decreasses with increasing concentration of aluminon, though the effect of pH becomes greater. The recommended procedure is as follows.
To a solution containing 432γ of beryllium are added 1 ml (or 5ml) of 2.5% EDTA, 10ml of reagent solution (0.500g of aluminon, 272g of sodium acetate trihydrate and 27ml of acetic acid in 1l, pH 5.3±0.05) and 5ml of 0.5% gelatin. The solution is gently boiled for 5 minutes, cooled.and diluted to 50 ml with water, the optimum pH in this case being Absorbancy is measured using Hitachi No. 53 filter (530 mμ). The determination is carried out with an error of less than 2%, and the time required for an analysis is about 20 minutes. Aluminum less than 250-fold of beryllium, and copper, iron, lead, zinc, calcium or magnesium less than 2, 000-fold do not interfere.
The method is easily applicable to various kind of sample, i. e., beryllium ores, intermediates or products from beryllium-copper industries, etc.View full abstractDownload PDF (1068K) -
Jutaroh SETO1960 Volume 9 Issue 11 Pages 939-945
Published: November 05, 1960
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThermal decompositions of 21 compounds including refined amino acids derived from proteins, their derivatives and betaine were clarified by use of a " Tokoshi " type thermobalance and the following results were found:
(1) On each compound, the loss in weight was represented by a typical curve as indicated in Fig. 2 and carbonization began after passing through 5 steps or more. Namely, aliphatic amino acids, aliphatic hydroxyamino carboxylic acids, aromatic aminocarboxylic acids and sulfur-containing aminocarboxylic acids were found more stable when they have short side chains and straight formula. They maintained a stable stage after removal of water, followed by the loss of 2% in weight, passed through another stable stage, then melted at 220°C or above and thereafter decomposed with a rapid loss in weight and finally carbonized.
(2) The thermal decomposition of L-valine and L-aspartic acid showed slower carbonization than the other amino acids.
(3) Such compounds as L-lysine hydrochloride dihydrate, sodium L-glutamate monohydrate, Lhistidine hydrochloride monohydrate, etc. having the water of crystallization, lost their water at a certain temperature and turned into a stable anhydrate.
(4) The thermal decomposition temperatures of all amino acids examined were lower than. heretofore reported values.
(5) Although L-histidine hydrochloride monohydrates recrystallized from different solvents showed the same [α]20D, they showed different aspects of thermal decomposition.View full abstractDownload PDF (971K) -
Jutaroh SETO1960 Volume 9 Issue 11 Pages 946-952
Published: November 05, 1960
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDNFB has been used as an efficient reagent in the chemical analysis of amino acids. In order to find substituents for this reagent by application of tropolone methyl ether, several N-troponylamino acids were synthesized and their properties have been investigated through their derivatives.
(1) Tropone was synthesized from cycloheptatriene by a slight modification of the Nozoe's method.
(2) Tropolone methyl ether and ethyl esters of amino acids (glycine, leucine, phenylalanine and glutamic acid) were reacted for formation of ethyl esters of N-troponylamino acid and their hydrolysis yielded respective troponylamino acid.
(3) Ultraviolet and infrared absorption spectra of N-troponylamino acids and their esters were estimated.
(4) Copper salts of N-troponylamino acids were synthesized by shaking benzene solution of N-troponylamino acids with copper sulfate solution, and their ultraviolet and infrared absorption spectra were estimated.View full abstractDownload PDF (902K) -
Keiichiro HOZUMI, Kingo MIZUNO1960 Volume 9 Issue 11 Pages 952-955
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSFor the titration of silver ion with the use of an indicator, the Volhard method is widely used, but the change of color at the equivalent point is obscure for titration of a trace amount, and the method gives poor reproducibility of titration. Dissolving a small amount of iodine in a 0.01N standard solution of potassium iodide and adding it dropwise into a sample solution containing silver ion with a starch solution, a clear end point of titration from light yellow to deep blue at the equivalent point is given. The color change is affected a little by the amount of iodine in potassium iodide solution but the effect can be minimized when the iodine content is 1/101/20 of the wt. of potassium iodide. This method has an advantage of requiring few kinds of reagents, with good reproducibility of the result and increased of stability of the titrating solution.View full abstractDownload PDF (761K) -
Keiichiro HOZUMI, Kingo MIZUNO1960 Volume 9 Issue 11 Pages 956-957
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSA sample solution containing a small amount of iodide ion was treated with ethanolic solution of iodine and starch for its coloration and this was titrated for its decolorization with 0.01N standard silver nitrate solution. An addition of 0.30.4 ml of 0.1% iodine-ethanol solution gave the best result when the concentration of iodide ion in the sample solution was below 0.01N and the volume of the sample solution was 10 ml. In general, the method showed a tendency to give some increased error on the upper or lower range of titration values. However, by selecting the titration values between 0.5 to 8ml, a fairly accurate result of determination could be obtained even with the use of 0.20.5ml iodine-ethanol solution.View full abstractDownload PDF (392K) -
[in Japanese], [in Japanese]1960 Volume 9 Issue 11 Pages 958-959
Published: November 05, 1960
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESS -
[in Japanese], [in Japanese]1960 Volume 9 Issue 11 Pages 959-961
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESS -
[in Japanese]1960 Volume 9 Issue 11 Pages 961-963
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESS -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1960 Volume 9 Issue 11 Pages 963-964
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESS -
[in Japanese], [in Japanese]1960 Volume 9 Issue 11 Pages 965-973
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSDownload PDF (2047K) -
[in Japanese], [in Japanese]1960 Volume 9 Issue 11 Pages 974-978
Published: November 05, 1960
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSDownload PDF (1053K)
- |<
- <
- 1
- >
- >|