Yasumasa Sayama
MITSUBISHI MATERIALS CORPORATION
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Featured researches published by Yasumasa Sayama.
Fresenius Journal of Analytical Chemistry | 1995
Yasumasa Sayama; Yutaka Hayashibe; Masamitsu Fukuda
Traces of cadmium and bismuth in high-purity zinc metal were determined by inductively coupled plasma mass spectrometry (ICP-MS) in combination with flow injection (FI) on-line matrix separation (FI-ICP-MS). The anion-exchange separation method of the potassium iodide (KI) system was applied to the separation of the analytes from the matrix zinc. The analytes, cadmium and bismuth, were adsorbed on the anion-exchange (BIO·RAD AG1-X8) mini-column (1.0 mm i.d.×100 mm bed length), while the matrix zinc can be completely removed from the anion-exchange resin. The analytes were eluted by 2 mol/l HNO3 and directly introduced into the ICP-MS. The detection limits (D.L.) obtained by using a single injection (350 μl) were 0.81 and 0.075 ng g−1 for cadmium and bismuth, respectively. In the case of multi-injection concentration onto the anionexchange mini-column (five injections 350 μl each), the detection limits could be improved to 0.16 and 0.014 ng g−1 for cadmium and bismuth, respectively. The reproducibilities of the single injection and the multi-injection method were satisfactory with a relative standard deviation of less than 5% (at the 10 and 1 ng ml−1 level for the single injection and the multi-injection method, respectively). The method was successfully applied to the determination of trace impurities in four samples of high-purity zinc metal (7 nines grade) and three standard reference materials of high-purity unalloyed zinc samples (from NIST).
Analyst | 1996
Yutaka Hayashibe; Yasumasa Sayama
A flow-injection (FI) method was developed for the spectrophotometric determination of cadmium in a hydrometallurgical zinc refining process stream using 1-(4-nitrophenyl)-3-(4-phenylazophenyl)triazene (Cadion) as the chromogenic reagent. The sample solution was injected into a carrier containing potassium iodide. The sample was then passed through an anion-exchange mini-column on which the analyte was concentrated as a cadmium–iodo complex. In order to extend the detectable range of cadmium, a multiple sample injection method, in which the sample solution was repeatedly injected into the carrier at regular intervals of 30 s, was applied. Cadmium on the column was eluted with 1 mol l–1 nitric acid and merged with a stream of a mixture of masking agent (trisodium citrate–potassium sodium tartrate–potassium hydroxide) and Cadion. Finally, the absorbance of the cadmium–Cadion complex was measured at 480 nm. The proposed FI was fully controlled by a personal computer. The proposed system permitted throughputs of 6 samples h–1 for single injection, and 2 samples h–1 for single injection, and 2 samples h–1 for multiple sample injection (50 injections). The reproducibility was satisfactory with a relative standard deviation of less than 5.0%(0.14 µg ml–1 Cd level, n= 5) for the single injection method and 10%(2.0 ng ml–1 Cd level, n= 5) for the multiple sample injection method (50 injections). The detection limits were 0.028 µg ml–1 of cadmium for the single injection method and 0.83 ng ml–1 of cadmium for the multiple sample injection method (50 injections). The absolute amount of cadmium detectable, defined as the analytical signal equal to twice the uncertainty in the background, was 10 ng.
Bunseki Kagaku | 1992
Yutaka Hayashibe; Minoru Takeya; Yasumasa Sayama
フローインジェクション法により,高塩濃度溶液中(亜鉛電解用硫酸亜鉛溶液)の0.1μg ml-1レベルのコバルトを定量した.試料をキャリヤー(0.25M硫酸)に注入し,緩衝液(酢酸アンモニウム-クエン酸二アンモニウム)の流れと合流させた後,発色試薬{1.0%(w/v)ニトロソR塩}を注入して,コバルト-ニトロソR錯体を形成させる.最終的に干渉除去剤{2M硫酸-1%(v/v)H2O2}の流れと合流させた後,分光光度計に導入して吸光度(480nm)を測定し,コバルトを定量する.ポンプ流量の変動,及び分光光度計の変動を補正するために試料測定前に発色試薬のみを系内に注入して,試薬から試験値吸光度を測定してシステムの補正を行う.本システムの分析速度は6試料/時であり,測定精度RSDは8.0%(0.5μg ml-1レベル,n=3)である.
Archive | 1995
Yutaka Hayashibe; Yasumasa Sayama
Archive | 1993
Yutaka Hayashibe; Minoru Takeya; Yasumasa Sayama
Archive | 1994
Yutaka Hayashibe; Minoru Takeya; Yasumasa Sayama
Archive | 1997
Masaaki Katou; Yutaka Hayashibe; Minoru Takeya; Yasumasa Sayama
Archive | 1997
Hiroyuki Sakurai; Yutaka Hayashibe; Minoru Takeya; Yasumasa Sayama
Analytical Sciences | 1993
Tadahiro Fukaya; Minoru Takeya; Yasumasa Sayama
Analytical Sciences | 1995
Hai-Long Wu; Yutaka Hayashibe; Yasumasa Sayama; Masami Shibukawa; Koichi Oguma