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

Abstract

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