Question

A SC kit requires the addition of 1-3 ml containing no more than 500mCi of TcO4-. in addition, 1.5 ml of solution A must be added before boiling, and 1.5 ml of Solution B must be added after cooling. If the kit is correctly prepared, what is the max concentration of Tc99m it could contain?

a. 83 mCi/ml
b. 125 mCi/ml
c. 167 mCi/ml
d. 500 mCi/ml

Answer 1

The maximum concentration of Tc-99m the kit could contain is 125 mCi/ml, calculated by dividing the maximum radioactivity (500mCi) by the total volume after preparation (4ml).

Step-by-step explanation:

To determine the maximum concentration of Tc-99m in the kit, you must consider the volume and the maximum amount of radioactivity as given in the question. The maximum radioactivity allowed is 500mCi, which is added to the SC kit in a volume between 1-3ml. To calculate the maximum concentration, use the scenario where the lowest volume (1ml) is used because concentration is inversely proportional to volume. After preparation, the total volume in the kit will be the volume of TcO4- added plus the volumes of Solution A (1.5ml) and Solution B (1.5ml).

The total volume after preparation is 1ml + 1.5ml + 1.5ml = 4ml. With a maximum of 500mCi of Tc99m, the concentration would be 500mCi divided by 4ml, which equals 125mCi/ml. Therefore, the maximum concentration of Tc99m the kit could contain is 125 mCi/ml.