A novel method of separation of 99mTc from (n, γ) 99Mo using Dowex 1 column

370 Objectives: 99mTc is commonly available by eluting alumina column pre-absorbed with 99Mo of high specific activity obtained by thermal neutron fission of 235U. Concerted efforts have been put to develop user-friendly 99mTc delivery systems using 99Mo of low-medium specific activity obtained by neutron activation of natural MoO3 targets. The aim of this study is to develop an inexpensive method to obtain pertechnetate solution with high radioactive concentration using a low specific activity 99Mo obtained from 98Mo(n,γ)99Mo. Methods: A low to medium specific activity 99Mo-Moly solution of 200-500mCi in sodium hydroxide was passed through a tiny Dowex-1 column (25mg) to absorb 99mTc from 99Mo and subsequently the eluted 99mTc from Dowex 1 column in tetrabutyl-ammonium bromide (TBAB) solution (1mg/ 5ml methylene chloride) was passed through a small alumina column (1.5g) to retain 99mTc in alumina column removing TBAB and CH2Cl2. The 99mTc was finally eluted with 3-5ml saline from alumina column leaving traces of 99Mo in the alumina column. The quality control of pertechnetate and efficacy in labeling of kits of EC, L,L-ECD, d,l-HMPAO, MDP and MIBI were checked. Results: The yield of separation was about 80-90% (n=5). All the 99mTc eluates were clear solution with a pH 6-7. 99Mo breakthrough was 99%, while that of the labeled compounds was >95%. The content of Al and Mo showed Conclusions: Therefore, it will be possible to prepare a large amount of Na99mTcO4 in high radioactive concentration from (n,γ)99Mo for use in larger nuclear medicine centres.