Testing: Tc/Mo Generators

Required QC Testing of a Mo/Tc Generator NRC State
TEST	FREQUENCY	SPECIFICATIONS
Mo Breakthrough	Every Elution	<0.15 uCi Mo/mCi Tc at t_{administration}
Al³⁺ Breakthrough	Not Required	<10 ppm of Al³⁺; may be expressed as ug/ml
Required QC Testing of a Mo/Tc Generator Agreement State
Mo Breakthrough	Every Elution	<0.15 uCi Mo/mCi Tc at t_{administration}
Al³⁺ Breakthrough	Required in Some States	<10 ppm of Al³⁺; may be expressed as ug/ml
Optional QC Testing of a Mo/Tc Generator Agreement State
HR Tc	Every Elution	< 2% (Reasonable limit; presently no legal limit)

Mo-99 breakthrough:

Mo-99 is assayed directly in the special lead pig supplied by manufacturer of your dose calibrator. Tc-99m is then assayed directly in the plastic sleeve. Activity (uCi) of Mo-99 is divided by activity (mCi) of Tc-99m to obtain a ratio.

If this ratio is <0.15 uCi Mo-99 per mCi of Tc-99m at time of administration, the generator eluate has passed the Mo-99 Breakthrough Test. As a rule of thumb, if the ratio is <0.038 at time of elution, the material will be suitable for injection for at least 12 hours.

Aluminum Ion Breakthrough: Al³⁺ ion is measured colorimetrically. A drop of the eluate is placed on one end of a special test paper; a drop of a standard solution of Al³⁺, concentration 10 ppm, is placed on the other end of the test strip. If the color at the center of the drop of eluate is less red than that of the standard solution, the eluate has passed the Al³⁺ Ion Breakthrough Test. Units may be also be expressed as ug/ml.