No abstract

<p>Alumina is usually used for ⁹⁹Mo absorbers obtained from ²³⁵U fission product because the use of ²³⁵U is getting limited, and as an alternative ⁹⁹Mo obtained from natural MoO₃ irradiation was used. The problem is that ⁹⁹Mo produced was not carrier-free as ⁹⁹Mo from ²³⁵U fission product because not all MoO₃ is activated to ⁹⁹Mo, then it is necessary to know the effect of contact time when loading ⁹⁹Mo into the alumina column. To find out the effect of contact time, the experiment was carried out using ⁹⁹Mo 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 ⁹⁹Mo/^99mTc generator is performed 3 times, days 1, 2 and 3. The results showed that the performance of alumina in absorbing ⁹⁹Mo influenced by time. The optimal contact time is 15 minutes for 0.9% NaCl solution and 45 minutes for MEK. The amount of ⁹⁹Mo breakthrough (µCi⁹⁹Mo/mCi^99mTc) from the alumina column increases with elution time both using 0.9% NaCl or MEK. The ^99mTc eluate obtained from this study does not meet standard requirements. The use of a tandem column is needed to prevent ⁹⁹Mo breakthrough on the ⁹⁹Mo/^99mTc generator to get the ^99mTc which meet standard requirement.</p>