Packaging and storage—
The generator column is enclosed in a lead container. The unit is stored at room temperature.
Labeling—
The labeling indicates the name and address of the manufacturer, the name of the generator, the quantity of
81Rb at the date and time of calibration, and the statement, “Caution—Radioactive Material.” The labeling indicates that in making dosage calculations, correction is to be made for radioactive decay, and also indicates that the radioactive half-life of
81mKr is 13.1 seconds.
NOTE—Perform the following tests and Assay quickly, because of the rapid decay of the 81mKr.
Radionuclide identification (see Radioactivity 
821
)—
The gamma-ray spectrum of eluted
81mKr exhibits a monoenergetic gamma ray at a mean energy of 191 KeV.
Radionuclidic purity—
Using a suitable counting assembly (see
Selection of a Counting Assembly under
Radioactivity 821), determine the radioactivity of each radionuclide present in a specimen of Kr 81m gas obtained from eluting the generator by use of a calibrated system as directed under
Radioactivity 821. Not less than 99.9% of the radioactivity in the specimen eluted from the generator is present as
81mKr.
Assay for radioactivity—
Using a suitable counting assembly (see
Radioactivity 821), determine the quantity, in MBq (mCi), of Kr 81m contained in an elution of the generator. Decay correct the result to the time of generator elution, and calculate the quantity of
81Rb present in the column at the time of elution. The quantity of
81mKr eluted is not less than 80.0 percent of the labeled MBq (mCi) of
81Rb present on the column at time of elution.
