An attempt for determining U-235/U-238 ratio for a trace amount of uranium: Search for an extinct radionuclide Cm-247 in the early solar system

作者：Chai J Y^*; Miyamoto Y; Kokubu Y; Magara M; Sakurai S; Usuda S; Oura Y; Ebihara M

来源：Journal of Radioanalytical and Nuclear Chemistry, 2007, 272(2): 397-401.

DOI：10.1007/s10967-007-0535-0

In order to search for isotopic anomalies of U caused by the disintegration of Cm-247 in meteorite samples, an analytical scheme for determining U-235/U-238 ratio for a small amount of uranium (less than 1 ng U) was established. The isotopic ratio of U was determined by double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS). With a great improvement of chemical procedure for purifying the uranium fraction separated from meteorite samples, a variation in U-235/U-238 ratios was resolved at an order of +/- 4% for 100 ppt or 200 pg U in solution. For applying the procedure in searching an evidence of Cm-247 as an extinct radionuclide in the early solar system, a selective chemical dissolution of constituent minerals of meteorites using EDTA and HCl was introduced and a chemical purification scheme of uranium for ICP-MS was established.

• 出版日期2007-5