Design of the Generator Column

Sterile saline is used for elution of the Tc activity as Tc(VII)04-pertechnetate anion. 

The sterile, isotonic eluate may be used directly in patients however, most of the Tc activity is needed for the preparation of Tc radiopharmaceuticals with preformed kits. 

Aluminum oxide is pretreated by activation at high temperature (250 °C) to resist structural changes in the high-radiation environment and to reduce acid solubility. Silver coating of the alumina particles has a similar effect and provides a higher capacity of the alumina matrix for fixation of Mo-molybdate (Barnes and Boyd 1982). 

Fission-produced molybdenum-99 offers considerable advantages for generator production  

With fission-produced Mo, the column for a 500-mCi generator requires approximately 1.2 g of aluminum oxide. The applied mass is by a factor of 1000 less than with previously used irradiation-produced Mo the elution volume is generally 5 ml, containing 80% of the theoretically available activity. To date, practically all commercially available generators are produced with fission-produced Mo problems with Mo breakthrough do not exist. An acceptable contamination of the eluate with Mo is highest in the first eluate, decreasing with daily elutions. 

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