Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 47 (2014)

Production of purified 85Sr solution
S. Yano,*1 ,*2 Y. Wakitani,*1, *2 T. Yamada,*1, *2 J. Kanaya,*2 S. Shibata,*2 and H. Haba*2
Since 2007, we have distributed purified radioisotopes suchas 65Zn, 88Y, and 109Cd to the general public.1) After theFukushima Dai-ichi Nuclear Power Plant accident in 2011,
the demand for 85Sr solutions having a high specificradioactivity has been growing. In this work, weinvestigated the production of 85Sr in the 85Rb(d,2n)85Sr
reaction using a 24-MeV deuteron beam from the RIKEN
AVF cyclotron. We also studied a chemical procedure toobtain a purified 85Sr solution.
85Sr (T1/2 = 64.853 d) was produced by irradiating an RbCldisk (Sigma-Aldrich; chemical purity: > 99.99%; thickness:
500 mg cm-2) of natural isotopic abundance with 24-MeVdeuterons. The average beam intensity was 159 nA. The
irradiation time was 17 min. 85Sr was chemically separatedin accordance with the scheme shown in Fig. 1. The
irradiated RbCl target was dissolved in 2 mL of H2O and 2mL of 8 M HNO3. After evaporating the solution almost todryness, the residue was again dissolved in 2 mL of 8 M
HNO3. The resulting solution was evaporated to dryness toremove chloride ions, and the residue was dissolved in 4mL of 8 M HNO3 and loaded onto a reversed-phaseextraction chromatography column ( 5 mm×50 mm height)
packed with Sr Resin (Eichrom; 100–150 mesh). The
column was then washed with 12 mL of 8 M HNO3. In thisprocess, 85Sr was absorbed on the Sr Resin, and the targetmaterial of Rb was completely eluted, as traced withbyproducts of 84Rb and 86Rb. 85Sr was then eluted with 8mL of 0.05 M HNO3. The eluent was evaporated to dryness,and the residue was dissolved in 1 mL of concentrated HCl(c. HCl). After evaporating the solution almost to dryness,the residue was dissolved in 2 mL of 0.1 M HCl and loaded
onto a column ( 5 mm×40 mm height) packed with acation-exchange resin (Dowex 50W×8; 200–400 mesh).
The column was then washed with 3 M HCl. 85Sr waseluted with 6 M HCl. The activity of 85Sr was determinedthrough -ray spectrometry using a calibrated Ge detector.
The -ray spectra of the produced 85Sr are shown in Fig. 2.
The produced activity of 85Sr was 145 kBq, and theradionuclidic purity was > 99.9%. The production yield of85
Sr under the present experimental condition was about 3
MBq A-1 h-1. The chemical yield was 89%.
The chemical impurity in the purified solution will beevaluated by using ICP MS for a control sample, which wastreated using the same procedure as that used for theirradiated sample, in further studies.

*1*2RbCl (880 mg)
H2O : 2 mL, 8 M HNO3 : 2 mLheat to dryness
8 M HNO3 : 2 mLheat to dryness
8 M HNO3 : 4 mL
8 M HNO3 : 2 mL×60.05 M HNO3 : 2 mL×4

Sr Resin, 100-150 mesh; f 5 mm×50 mm height
discardheat to dryness
c. HCl : 1 mLheat to dryness
0.1 M HCl : 2 mL
3 M HCl : 1 mL×3

6 M HCl : 1 mL×5Dowex 50W×8, 200-400 mesh; f 5 mm×40 mm height
discard85Sr

Counts/Channel
Countsper 0.5 keVCounts/Channel
Counts per 0.5 keV

Fig. 1. The chemical separation procedure of 85Sr from theirradiated RbCl target employed in the present study.
10101010101010101010(a)485 Sr : 514 keV
85

Sr

384 Rb84: 882 keV
86
86Rb : 1077 keVRb

2Rb

100500(b)

485

Sr

1000
1500
Energy in keV

2000

85 Sr : 514 keV

321005001000
1500
Energy in keV

2000

Fig. 2. The measured -ray spectra of the produced

85Sr. (a)and (b) were obtained before and after the chemicalseparation, respectively.
References
1) T. Kambara et al.: a separate paper in this issue.

Japan Radioisotope Association
RIKEN Nishina Center- 279 -