Question

A vial containing radioactive selenium-75 has an activity of 2.3 mci/ml. If 2.6 mci are required for a leukemia test, how many microliters must be administered?

Answer 1

Answer is: 1130 microliters must be administered.

activity(selenium-75) = 2.3 mCi/mL.

radioactivity(Se-75) = 2.6 mCi; mCi is millicurie.

The curie (symbol: Ci) is a non-SI unit of radioactivity.

V(Se-75) = radioactivity(Se-75) ÷ activity(Se-75).

V(Se-75) = 2.6 mCi ÷ 2.3 mCi/mL.

V(Se-75) = 1.13 mL; volume.

V(Se-75) = 1.13 mL · 1000µL/mL.

V(Se-75) = 1130 µL.