Seiichiro Hikime

Spectrophotometric determination of small amounts of tellurium with bismuthiol II

A spectrophotomeiric method of determining small amounts of tellurium in acidic media with Bismuthiol II has been studied. The tellurium complex with bismuthiol II is extracted almost quantitatively with chloroform from a 3M hydrochloric acid solution or from a solution buffered at pH 3.5. Up to 25 mug of tellurium can be determined by measuring the absorbance of the yellow complex in the chloroform phase at a wavelength of 330 mmu, after washing the chloroform extract with a buffer solution (pH 7.5) to remove the excess reagent from the organic phase. The effects of diverse ions on the determination of tellurium have also been examined. This method is more simple and more sensitive than the methods proposed by Jankovsky et al. and by Cheng.

Spectrophotometric determination of small amounts of tellurium with sym-diphenylthiourea

Abstract A spectrophotometric method of determining small amounts of tellurium in acidic media with sym -diphenylthiourea has been studied. Tellurium is extracted almost quantitatively from 4·5–8·0 M hydrochloric or perchloric acid solutions with a chloroform solution of diphenylthiourea, and up to 200 μg of tellurium can be determined by measuring the absorbance of the yellow complex in the chloroform phase at a wavelength between 380 and 410 mμ. The effects of diverse ions on the determination of tellurium have also been studied. It has been found that this method, with an extraction procedure, is more simple and more sensitive than the usual thiourea method in an aqueous medium.

Application of urease for the precipitation of nickel dimethylglyoximate by urea from homogeneous solution.

Urease can be used to decompose urea for the precipitation of nickel dimethylglyoximate from homogeneous solution. Optimum experimental conditions, and a procedure giving good separations from other ions, are described.

Application of urease to the precipitation of manganese (II) oxinate from homogeneous solution with urea in the presence of calcium

The effect of calcium on precipitation of manganese(II) oxinate from homogeneous solution by means of decomposition of urea with urease was investigated. Manganese was determined satisfactorily in the presence of calcium.

Precipitation of magnesium ammonium phosphate from homogeneous solution by means of hydrolysis of p-nitrophenylphosphate with an alkaline phosphatase

In the precipitation of magnesium ammonium phosphate from homogeneous solution, phosphate ions were generated by means of hydrolysis of p-nitrophenylphosphate with an alkaline phosphatase. Conditions for the gravimetric determination of magnesium ion as magnesium ammonium phosphate hexahydrate were investigated.

Electron microscopy studies of the precipitate of zinc 8-hydroxyquinaldate

亜鉛8-ヒドロキシキナルデート沈殿を常法および均一溶液からの沈殿(PFHS)法によって生成し,電子顕微鏡により研究した。沈殿は1分子の結晶水をもち,組成はZn(C10H8ON)2・H2Oである.結晶は斜方晶系に属し,沈殿粒子は(010)面にそって成長した薄い板状である.沈殿粒子を乾燥器中もしくは電子顕微鏡中において加熱すると,脱水されて結晶構造は変化する.しかし,ごくわずかの結晶を電子顕微鏡用試料台にのせて,乾燥器中にて130℃で長時間加熱すると,無水の結晶はもとの水和した結晶と同一の回折像を示す.亜鉛8-ヒドロキシキナルデートの脱水による結晶構造の変化に対して,いくらかの水が関与するものと考えられる.

Quantitative Spectrographic Determination of Elements in Solution

溶液試料の分光分析法は多数提案されている.著者の一人(太秦)はさきにLundegardhが炎光分析に用いた噴霧装置を改良したものを閃光分析に応用して好結果を得た.しかし,それらの報文は定性分析乃至半定量法について報ぜられているので,今回は内部標準法による定量法を試みた.同様の方法で金森は鉄鋼および鋼塊の樹状晶の分析を行っている.著者等は前報と同じ噴霧装置を用い,溶液中に共存する数種の金属を,分析の精度を幾分犠牲にしても,簡易迅速に同時定量する可能性について研究した.カドミウムを単一の共通内部標準として選定し,Fe,Al,Ca,Mg,B,Mn,KおよびNaなどの分析を行った.KおよびNaについては,それらの濃度が1g/lまでも定量不能であった.マンガンを除く他の金属については簡易分析法として満足すべき結果を得たので報告する.