Influence of Contact Time on Loading 99Mo(n,γ) with Alumina Column in 99Mo / 99mTc Generator

Alumina is usually used for 99 Mo absorbers obtained from 235 U fission product because the use of 235 U is getting limited, and as an alternative 99 Mo obtained from natural MoO 3 irradiation was used. The problem is that 99 Mo produced was not carrier-free as 99 Mo from 235 U fission product because not all MoO 3 is activated to 99 Mo, then it is necessary to know the effect of contact time when loading 99 Mo into the alumina column. To find out the effect of contact time, the experiment was carried out using 99 Mo pH 4, acid alumina column, contact time was varied between 1 to 60 minutes with interval of 15 minutes, and the column was eluted using 2 kinds of eluent namely 0.9% NaCl and MEK. The elution of 99 Mo/ 99m Tc generator is performed 3 times, days 1, 2 and 3. The results showed that the performance of alumina in absorbing 99 Mo influenced by time. The optimal contact time is 15 minutes for 0.9% NaCl solution and 45 minutes for MEK. The amount of 99 Mo breakthrough (µCi 99 Mo/mCi 99m Tc) from the alumina column increases with elution time both using 0.9% NaCl or MEK. The 99m Tc eluate obtained from this study does not meet standard requirements. The use of a tandem column is needed to prevent 99 Mo breakthrough on the 99 Mo/ 99m Tc generator to get the 99m Tc which meet standard requirement.