| Co-Investigator(Kenkyū-buntansha) |
AIBA Yoko Gunma Univ., Fac. of Eng., Research Assistant, 工学部, 教務員 (20173106)
AIZAWA Shoichi Gunma Univ., Fac. of Eng., Assistant Prof., 工学部, 助手 (20008527)
TSUNODA Kin-ichi Gunma Univ., Fac. of Eng., Associate Prof., 工学部, 助教授 (30175468)
KAWAMOTO Hiroshi Gunma Univ., Fac. of Ehg., Associate Prof., 工学部, 助教授 (20008460)
|
|---|
| Budget Amount *help |
¥22,000,000 (Direct Cost: ¥22,000,000)
Fiscal Year 1990: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1989: ¥21,000,000 (Direct Cost: ¥21,000,000)
|
|---|
| Research Abstract |
1. Determination of alpha-emitters in semiconductor with ICP-ES
A method for the determination U and Th in molybdenum and molybdenum silicide was developed by using ICP-ES. The procedure for the determination is as follows : 0.1 gram of a sample was decomposed in HCI-HF by heating, and the resulting residue was dissolved in 6M HCI. The pH of the sample solution was then adjusted to ca. 1 by adding NaOH, and Th was extracted into TTA-C_6H_6 by shaking the mixture. The pH of the aqueous solution was adjusted to ca. 4 by adding NaOH. After the addition of TTA-C_6H_6, the mixture was shaken to extract U. To the resulting organicphase, the previous C_6H_6 solution containing Th was added, U and Th were then back-extracted into 3M HCI. After washing the aqueous phase with C_6H_<12>, the solution was applied to ICP-ES.
According to the proposed procedure, the ppm level of U and Th could be determined. However, for further sensitivity, namely ppt level, ICP-MS should be employed, and the research is now in progress.
2. Preconcentration of trace elements and their determination with ICP-ES.
A method for the preconcentration of trace elements by dithizone and TBPO-extraction and their determination with ICP-ES was also established. The proposed method enables us to determine sub-ppb level of Co, Ni, Cu, Zn, Cd, Pb simultaneously and these elements in a water sample taken from the Watarase River was shown to be : Cu : 85 <plus-minus> 5 ppb, Zu : 88 <plus-minus> 0.1 ppb, Cd : 0.75 <plus-minus> 0.002 ppb, Pb : 3.2 <plus-minus>
|
