Katsuaki Fukuda

Collection of traces of silver on powdered dithizone : Application of ultrasonics

Abstract Microgram quantities of silver can be collected on 5 mg of finely ground dithizone powder from 25 ml of 0.01–1 M nitric acid solution within 15 min by the use of ultrasonics. This separation method is successfully applied to the photometric determination of a few p.p.m. of silver in high-purity lead metal.

Solid-liquid extraction as a preconcentration technique in trace element analysis Extraction of trace impurities from metal chlorides.

Microgram quantities of iron, cobalt, copper, zinc and cadmium are extracted with various aqueous, organic and mixed solvents from chlorides of sodium, potassium, nickel, cadmium, barium and lead prepared by evaporation of aqueous sample solutions. An ultrasonic field accelerates the extraction, and satisfactory trace recoveries and separation factors are achieved in several systems within a reasonable time. The application to a polarographic determination and a two-stage separation technique are also described.

Collection of traces of silver on preformed p-dimethyl-aminobenzylidenerhodanine precipitates

Abstract Microgram or nanogram quantities of silver ion can be collected on 0.2–4 mg of preformed voluminous p -dimethylaminobenzylidenerhodanine precipitates from 50–2000 ml of 0.01–0.5 N nitric acid solution within 10 min. This separation method is successfully applied to the photometric determination of a few p.p.m. of silver in high-purity bismuth metal.

Further investigation on the solid-liquid extraction of trace impurities from basic bismuth nitrate

SummaryThe effect of heat treatment of basic bismuth nitrate on the extraction ofμg quantities of iron, cobalt and zinc with a 0.07M phosphoric acid-0.12M hydrochloric acid mixture or water has been studied to optimize the extraction procedure as a preconcentration technique in trace element analysis.ZusammenfassungDer Effekt der Hitzebehandlung von basischem Wismutnitrat auf die Extraktion von Mikrogrammengen Eisen, Kobalt und Zink mit einer Mischung aus 0,07-m Phosphorsäure und 0,12-m Salzsäure oder auch mit Wasser wurde untersucht, um den Extraktionsvorgang zwecks Anreicherung in der Spurenanalyse zu verbessern.

Solid-liquid extraction of trace impurities from potassium and lead nitrates and from lead sulfate

SummaryMicrogram quantities of iron, cobalt, copper, zinc, and silver are extracted with 0.14–14M nitric acid and mixtures of ethanol and nitric or hydrochloric acid from potassium and lead nitrates and lead sulfate. This technique is combined with the preliminary precipitation of the matrix element and applied to the atomic absorption spectrometric determination of low ppm of silver in high-purity lead.ZusammenfassungMikrogrammengen Fe, Co, Cu, Zn und Ag wurden mit 0,14-bis 14-m Salpetersäure und mit Gemischen von Äthanol und Salpeter- oder Salzsäure aus Kalium- und Bleinitrat sowie aus Bleisulfat extrahiert. Diese Arbeitsweise wurde mit der vorhergehenden Fällung des Matrixelementes kombiniert und auf die Bestimmung weniger ppm Ag in hochgereinigtem Blei im Wege der Atomarabsorption angewendet.

Collection of trace elements on tin(IV) hydroxide

SummaryMicrogram quantities of iron, cobalt, copper, and zinc in aqueous solutions can be collected on tin(IV) hydroxide precipitates in greater than 95% yields over the range of pH 4 to 8. Tin is easily removed by evaporation as bromide. This separation technique has been applied to the emission spectrographic determination of low ppm level impurities in high-purity magnesium metal.ZusammenfassungMikrogrammengen Fe, Co, Cu und Zn können in wäßrigen Lösungen an Zinn(IV)hydroxidniederschlägen bei pH 4–8 zu mehr als 95% angereichert werden. Sn kann als Bromid leicht abgedampft werden. Dieses Trennverfahren wurde zur emissionsspektrographischen Bestimmung geringer ppm-Verunreinigungen in hochgereinigtem Magnesiummetall angewendet.

Separation and determination of traces of copper in high-purity bismuth

高純度ビスマス中の0.xppmないし数ppmの銅の分離定量法2種を述べる. (1)昇華分離-炎光光度法: pH 8の試料溶液から銅をビスマスオキシン塩とともに沈殿させる.乾燥沈殿を,真空昇華装置に入れ, 380℃で銅を昇華させる.これを2M塩酸に溶解したのちクロロホルムで抽出し,有機相を酸水素炎中に噴霧する. (2)イオン交換分離-吸光光度法:試料の硝酸溶液(10ml, 3M NO3-)を強塩基性陰イオン交換樹脂カラムに通す.続いて3M硝酸を通し,銅を含むはじめのフラクションをとり,蒸発乾固後ネオクプロイン法で銅を定量する.両法とも分析所要時間は5～6時間である.