Which of the following is a radiochemical impurity in a Tc99m MDP dose?

In the context of a Tc99m MDP dose, identifying radiochemical impurities is essential for ensuring the quality and safety of the radiopharmaceutical. The primary radiochemical impurity in a Tc99m MDP dose is Tc99m Pertechnetate. This is because during the preparation of Tc99m MDP (methylene diphosphonate), some of the technetium can remain in the form of pertechnetate, which does not participate as intended in the targeted imaging but is instead an unbound form.

Aluminum is often monitored as a potential impurity in radiopharmaceuticals due to its presence in the vial or from the manufacturing process. However, it is not a radiochemical impurity specific to the compound of interest in this instance. Molybdenum-99 (Mo99) is the parent isotope from which Tc99m is derived. While it can indeed be a concern as a radionuclidic impurity, in this specific case, it is not classified as a radiochemical impurity of the final Tc99m MDP product itself.

Thus, while there are impurities that can be present in a Tc99m MDP dose, the primary radiochemical impurity that interferes with