Krypton Kr 81m
Kr 81m
Krypton, isotope of mass 81 (metastable). Krypton, isotope of mass 81 (metastable) ![]() ![]() ![]() » Krypton Kr 81m is a gas suitable only for inhalation in diagnostic studies, and is obtained from a generator that contains rubidium 81 adsorbed on an immobilized suitable column support. Rubidium 81 decays with a half-life of 4.58 hours and forms its radioactive daughter 81mKr, which is eluted from the generator by passage of humidified oxygen or air through the column. Rubidium 81 is produced in an accelerator by proton bombardment of Kr 82. Other radioisotopes of rubidium are produced and are present on the generator column. These other radioisotopes do not decay to 81mKr. The column contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of Rb 81 at the date and time indicated in the labeling, and on elution yields not less than 80.0 percent of 81mKr.
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, CautionRadioactive 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.
notePerform the following tests and Assay quickly, because of the rapid decay of the 81mKr.
Radionuclide identification (see Radioactivity
![]() ![]()
Radionuclidic purity
Using a suitable counting assembly (see Selection of a Counting Assembly under Radioactivity
![]() ![]() ![]() ![]()
Assay for radioactivity
Using a suitable counting assembly (see Radioactivity
![]() ![]()
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP32NF27 Page 2742
|