Kazuo Katsuyama

Spectrophotometric determination of ruthenium with 8-quinolinol

A spectrophotometric method is described for the determination of 2-80 mug of ruthenium. The method involves oxidation of ruthenium to ruthenate, addition of 8-quinolinol, adjustment of the pH to 4-6.5, digestion of the complex formed at 85 degrees for 30 min, extraction with chloroform, and measurement of absorbance at 430 nm. Almost all other metals and excess of reagent are removed by washing the extract. About 98 % of (106)Ru tracer was recovered.

Improvement on removal of radio-cobalt from waste water by ferric hydroxide coagulation-flocculation process using diethyldithiocarbamate

Abstract By adding a small amount of sodium diethyldithiocarbamate (Na-DDTC) in the ordinary decontamination process of low-level radioactive waste water by ferric hydroxide coagulation-flocculation, removal of radio-cobalt is remarkably improved. The quantity of Na-DDTC used is only 10 ppm in concentration, which does not affect the decontamination process, and no DDTC is detected in the treated water. High decontamination factors for radio-cobalt of 80–100 are obtained for the waste water containing 10 −4 μCi/ml level of radio-cobalt, and the values are about five times that without DDTC.

Extraction-photometric determination of molybdenum in zirconium-, nickel- and iron-base alloys using oxine

An extraction-photometric method for the determination of molybdenum in zirconium-, nickel- and iron-base alloys was established. One gram of zirconium-base alloys is dissolved in 10 ml each of sulfuric acid and 50% ammonium sulfate solution by heating. Molybdenum oxinate is formed by adjusting the pH to 0.851.2 in the presence of 10 ml of 5% oxine solution. The oxinate is extracted by shaking vigorously for 1 min. with 10 ml of chloroform. The chloroform solution is washed by shaking for 1 min. with 50 ml of 0.1 M oxalic acid solution. After the drying of the solution with anhydrous sodium sulfate, the absorbance is measured at 380 nm.Nickel- and iron-base alloys are dissolved in the mixed acid (nitric acid : hydrochloric acid : water = 1 : 1 : 1) by heating. The formation and extraction of the oxinate is carried out by the same way as described above except for analyzing a sample containing more than 0.01 g of iron. One gram of iron can be masked by addition of 2 g of ascorbic acid and adjusting the pH to 1.52.0. Less than 0.5 mg of tungsten is masked by addition of 0.2 g of fluoride ion before the extraction. According to this method, molybdenum in these alloys can be determined rapidly below the order of a few ppm.

Determination of traces of aluminum and manganese in zirconium and its alloys

原子炉燃料の被覆管として用いられるジルカロイ-2の分析を目的として,ジルコニウムおよびジルコニウム合金中の5ppm以上のアルミニウムおよびマンガンの定量法を確立した.試料は硫酸-硫酸アンモニウムで溶解する.400mgまでのジルコニウムをクペロン抽出で完全に除いたのち,さらに2-メチルオキシンでクロムなどを除去し,アルミニウムをオキシン抽出光度法で定量する.一方,マンガンは,ジルコニウムをクペロンで抽出除去したのち,pH 12±0.5から2-メチルオキシン錯塩としてクロロホルムに抽出し光度定量する.本法で最も重要なのはクペロン抽出によるジルコニウムの除去であり,試薬量,酸性度,フッ素イオンの影響などを詳しく検討した.

POLAROGRAPHIC DETERMINATION OF HEXAVALENT URANIUM IN URANIUM TETRAFLUORIDE

An analytical method is proposed for the polarographic determination of uranium(VI) in uranium tetrafluoride. A sample weighing about 500 mg is treated with 20 ml of 0.1M NaF solution using a magnetic stirrer, and is subjected to centrifugation. Two milliliters of the supernatant solution and 5 ml of supporting electrolyte solution (1.3 M HOAc + 0.7 M NH/sub 4/OAc + 0.2 M BeSO/sub 4/) are taken into a 10-ml volumetric flask and the resulting solution is diluted to the mark with water. Uranium(VI) in the solution is determined polarographically by referring to the standard calibration curve. For the purpose of suppressing the dissolution of uranium(IV) into the solution, NaF is used at the time of the sample digestion. The acetate buffer solution keeps the pH of the solution at 5 and Be/sup 2+/ ion removes the interference of F/sup -/ ion in the polarographic measurements. Al/sup 3+/ can be used instead of Be/sup 2+/ for the same purpose. By this method as small as 0.05% of uranium(VI) in uranium tetrafluoride can be readily determined. (auth)