Cation exchange resin was used for a separatory determination of cobalt in the copper electrolytic solution, which was prepared by the sulfating calcination of complex sulfide ores and contained large amounts of zinc, manganese, iron, etc.
A glass tube of φ 12.5 mm × 240 mm and a separatory funnel of 100 ml capacity were connected through a ground glass joint, and the tube was filled with 5 g of Na-type Amberlite IR-120 of 6080 mesh size. The bottom of resin column had a bed of Tevilon (polyvinyl chloride) cotton. An addition of a small amount of ammonium hydrogen fluoride made Fe³⁺ unexchangeable and remaining in the effluent by passing through the column. Copper adsorbed in the resin was liberated by 0.1M sodium thiosulfate and separated. The column was then treated with 2.5M sodium chloride, and cobalt was eluted together with zine, manganese, etc. The effluent could be directly applied for the colorimetric determination of cobalt with nitroso R salt.

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A separatory determination of zinc in metallic lead was made by use of cation exchange resin. A resin column of φ 14 mm×300 mm and a separatory funnel of 150 ml capacity were connected through a ground glass joint. This was filled with 15 g of Na-type Amberlite IR-120 of 6080 mesh size. Five g of metallic lead were dissolved in nitric acid, and 5060 ml of 0.5M sodium thiosulfate was added for precipitation of 9095% of lead as lead thiosulfate.
The filtrate was passed through the resin and the column was washed with 0.05M sodium thiosulfate for the liberation of lead alone. A solution of 2M sodium chloride liberated zinc, which was then determined by the dithizone method.

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Beta ray incident on the several elements comes from collimated ⁹⁰Sr source. The backscattered beta ray of desired backscattering angle was detected by a collimated GM counter. The absorption curve of scattered beta ray showed that the energy of scattered ray decreases as the scattering angle increases, especially for low atomic number elements, and the difference of backscattering coefficient between each element increases as scattering angle increases.
Relation between saturation backscattering coefficient and atomic number of backscatterer was examined. To improve the sensitivity of analysis of higher atomic number elements in two component system, it was desirable that the scattered ray with maximum scattering angle must be detected by use of a filter.

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Beta ray incident on the coal sample dried and crushed to <100 mesh comes from collimated ⁹⁰Sr source. The backscattered ray of 135° scattering angle was counted for 3 minutes each by a GM counter with or without Al filter. The standard deviation from the calibration curve between the backscattering intensity and the ash content (obtained by the JIS method) of 28 brands of coal, covering the range of 630% ash, was 0.85%. A reason of such deviation was attributed to the variation of the ash composition.

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From a solution containing ethylenediamine tetraacetic acid, tin is precipitated by aqueous ammonia as it forms a hydroxide together with the beryllium added as a coprecipitant. The precipitate is dissolved in hydrochloric acid, and the pH is adjusted to 1.7±0.2 by the use of potassium biphthalate buffer solution. Then, add oxidized hematoxylin, and heat to confirm the color development without separating beryllium. The light absorbancy is measured at 575 mμ. The proposed method has been followed in deterinining the amount of tin in cast iron, alloy tteels, iron ores, etc..

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The effect of concentration of thiocyanate and pH on the TBP extraction of copper-thiocyanate complex was investigated, and it was found that above 99.9% extraction was effectuated in the concentration of 0.21.2M of thiocyanate and with pH17. Also, the percentage recoveries by the ammonia reextraction of the solventextracted copper indicated that thiocyanate concentration and pH had marked influences on the copper recovery. Namely, an increase in the thicyanate concentration or a lowering of pH was followed by a considerable decrease in the per cent recovery. However, using of TBP-benzine (1:1) as a solvent caused an increase in the reextraction rate and a recovery rate above 99% in the ammonia reextraction was obtained with 0.20.8M thiocyanate under the pH 15.
The method was applied for separation of copper in aluminum alloy followed by the determination of copper by thiosulfate titration. Good result was obtained for 14% copper.

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A simple and rapid method for the determination of niobium in ferro-niobium and Nb-containing slag by A. C. polarography excluding an extraction with organic solvent has been studied.
Samples were dissolved in hydrofluoric acid and evaporated almost to dryness, and redissolved into concentrated hydrochloric acid. In the case of ferro-niobium, ferric ion was reduced to ferrous ion by adding stannous chloride. After the solutions were diluted to a definite volume with concentrated hydrochloric acid, niobium was determined by A.C. polarography.
The analytical results were comparable with those obtained by the gravimetric method with satisfactory agreements.
The time required for an analysis was about an hour.

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Gas-liquid chromatographic method was applied for the analysis of 1, 2-dibromo-3-chloropropane (DBCP) in technical products, preparations as emulsions and oils, and the following results were obtained.
The samples containing ethyl benzoate (EB) as the internal standard, were analyzed in a Shimadzu Gas Chromatograph 2A, with thermal conductivity detection using helium as the carrier gas, the flow rate of which was 70 ml per minute.The column (4mm×3m) contained 20 weight % Silicone DC 550 as a stationary phase on a support of Celite 545, and the column temperature was adjusted to 150°C.
The retention times from the air peak of DBCP and EB were, respectively, 5.4 to 5.6 and 6.9 to 7.0 minutes.A calibration curve in the range 0.6 to 5.0 weight ratio (DBCP/EB) was an almost straight line. The standard deviations were 0.11% at the technical products, 0.56% at the emulsions and 0.60% at the oils, respectively. The analytical results on DBCP in technical products by the proposed method were in good agreement with the results found by the argentimetry.

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A method has been described for the ionexchange and photometric determination of microgram quantities of copper in alkali industry.
Sample of the alkali products such as soda ash and caustic soda was acidified with 12N HCl and the pH value was adjusted to 35. This solution was passed through the Dowex A-1 resin column at the rate of about 6 ml per min. Copper was then eluted from the column with 2N HCl and the effluents were gathered in a separatory funnel, to which were added 10 ml of the combined reducing reagent (NH₂OH·HCl+Na-citrate) and NH₄OH to adjust the pH 46. 5ml of 0.1% neocuproine were added and the resulted brownish complex was extracted with exactly 10 ml of CHCl₃. The absorbancy was measured with a spectrophotometer at 460 mμ.
Copper in alkali products was determined accurately by this method, the time required for a determination being about four hours.

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The colour reaction at the titration end point of semimicro higher alcohol-metallic sodium method for the volumetric determination of organic halogens has been improved by using nitrobenzene in place of ether as a reaction inhibitor of the precipitates.
The improved method proved to be satisfactorily applicable for a wide range of industrial products, such as laurylbromide, B. H. C., D. D. T., 2, 4-D, 2, 4-dichlorophenol, 2, 3-dichloro-amino-anthraquinone, 3, 3'-dichloroindanthrone, 5, 5'-dibromoindigo, 5, 5', 7, 7'-tetrachloroindigo, tetrachlorobenzoquinone, dichlorofluoresceine, polyvinyl chloride, polyvinyliden chloride, and copolymer, using n-butanol, iso-amyl alcohol, octyl alcohol, cyclohexanol, or methyl hexaline with 0.20.6g of metallic sodium in the reduction stage.

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A fundamental study for application of X-ray diffractometer on industrial analysis was made using brass as the sample, in which the alloy was converted into a mixture having a definite composition by a preliminary chemical treatment and this was subjected to the X-ray diffractometric analysis.
The brass was dissolved in nitric acid and the resulted nitrate was decomposed by heating at 500°C. The complete conversion of copper and zinc into their oxides was achieved by successive 30 min. heating at 900°C.
An accurate determination of copper within ±2% error was possible by subjecting the oxide (ground for 30 min. in an agate mortar) to the X-ray diffractometry. The area of diffraction peak (height × half value width) was taken as the index of diffraction line intensity.
The values obtained by the proposed method on a standard sample of brass agreed well with those by chemical analysis.

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Fundamental studies on the application of X-ray diffractometer on the analysis of slags were made in which (1) the conditions for formation of melilite in blast-furnace slag were investigated.
The melilite obtained as crystalline form from a mixture of pure substances was always accompanied with a small amount of merwinite, which could be removed by treating with methanolic bromine or citric acid remaining pure melilite.
By this treatment, the detection of a small amount of dicalcium silicate in blast-furnace slag became more available.
(2) Although the complicate mineral composition of copper slag rendered its rational analysis.difficult, the X-ray diffractometry on the residue after the treatment with methanolic bromine or that with citric acid revealed that the main constitutional minerals in copper slag were 2FeOSiO₂, CaO·Fe₂O₃, α-ZnS, β-ZnS, FeO·Fe₂O₃, ZnO·Fe₂O₃.

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Gallium reacts with Brilliant green in a 6N hydrochloric acid solution to form a stable blue color that can be extracted with benzene.
Its maximum absorbancies appear at 430 mμand 635 mμ. At the latter wavelength, the photometry can be done with a higher sensitivity. Beer's law is obeyed over the range of 1 to 15 γ/10 ml of gallium in benzene.
In the proposed method applying the reaction to the spectrophotometric determination of gallium, iron(III) and thallium(III) cause a serious interference, which, however, can be eliminated provided they are reduced preliminary by adding titanous choride solution.
The method has been applied to the determination of gallium in the residue of zinc refining and good resluts are obtained.

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Several conditions for the spectrophotometric determination of gallium with 4-(2-pyridylazo)-resorcinol [PAR] have been studied.
The colored solution of gallium-PAR shows a maximum absorption at 504 mμ, and follows Beer's law over a range of 1 to 15 γ/25 ml of gallium. The molar extinction coefficient at 504 mμ is estimated to be 102, 330. The absorbancy of the solution is kept constant for 20 hours and is not affected by temperature between 15 and 35°C. Since iron (III), cobalt nickel, indium, thallium (III), manganese (II), copper, bimuth, zinc, cadmium, aluminium, antimony (V) interfere more or less, the separation of gallium from some of the above ions by means of ether extraction has been studied.
The constitution of the complex examined by continuous variation method is that the molar ratio of gallium : PAR is 1 : 2.

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Metallic uranium was dissolved in hydrochloric acid and hydrogen peroxide, after addition of ammonium citrate, made ammonia alkaline with ammonium hydroxide, and potassium cyanide was added, and then cadmium etc. were extracted with dithizone-chloroform solution. This was taken up in hydrochloric acid, treated with ammonium citrate, sodium hydroxide, and potassium cyanide in the order named, and cadmium was extracted with dithizone-chloroform solution. The extract was washed with the mixed soln. of ammonium citrate, sodium hydroxide, potassium cyanide, and the light absorbance at 518 mμ was measured for determination of cadmium.
In an other method recommended, the sample was dissolved in nitric acid, made alkaline in the presence of ammonium citrate, dimethylglyoxime added for precipitation of nickel and others, cadmium, etc. were extracted with dithizonecarbon tetrachloride isolution, the extract after washing was passed through an alumina chromatographic column, cadmium was liberated by use of methanol-chloroform and determined by measuring the light absorbance.

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A rapid determination of nickel in metallic uranium was possible by developing the color by addition of dimethylglyoxime in the presence of bromine water under ammonia alkaline condition and determining the absorbance at 562 mμ. Also, a simple determination of nickel was possible by dithizone extraction and absorbance measurement at 800 mμ. Or, a separatory determination of nickel and cobalt by the alumina chromatography of their dithizone complexes was presented.
In order to investigate these methods, a fundamental experiment for conditions of extraction of complex dithizone salts of nickel and cobalt as affected by the pH, the concentrations of dithizone and citrate, time of shaking and the liberation from alumina column has been made and the results were given.

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A modification of the determination of a trace amount of phosphorus as an impurity in uranium metal was presented in which was used a methyl isobutyl ketone extraction of phosphomolybdic acid.
The sample was decomposed by heating with nitric acid and perchloric acid and this was concentrated by evaporation after an addition of sodium bromide for removing of arsenic. Ammonium molybdate was added to it and the phosphomolybdic acid formed was separated by extraction with methyl isobutyl ketone.The light absorbancy of Molybdenum Blue 725 mμ or 625 mμ formed by additions of alcohol and stannous chloride was measured for determination of phosphorus.
An accurate determination of 2 ppm of phosphorus in the uranium was possible by taking 0.5g of the sample and making it up to 20ml of the coloring solution.

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A new analytical method for determination of a trace amount of silicon in uranium metal was presented, in which silicon was extracted by methyl isobutyl ketone as silicomolybdate and photometrically estimated. The recommended procedure with good result was as follows.
The sample was dissolved in hydrogen peroxide and hydrochloric acid (acid-soluble Si) or it was dissolved in nitric acid, evaporated to dryness, the residue was fused with sodium carbonate and dissolved in hydrochloric acid (total Si). The concentration of hydrochloric acid was adjusted to 0.30.5N, ammonium molybdate was added for formation of silicomolybdic acid which was then separated by the extraction with methyl isobutyl ketone after an addition of oxalic acid. Molybdenum Blue was formed by additions of alcohol and stannous chloride and the silicon was determined by measuring the light absorbancy at 770mμ or 630mμ. 5150 ppm of silicon was accurately determined by taking 0.2g sample and making it up to 20ml of the coloring solution.

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[in Japanese]

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[in Japanese]

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