Radiochemical quality control of short-lived radiopharmaceuticals

Radiochemical purity, the fraction of radioactivity present in the specified chemical form, is a major factor determining the reproducibility of a nuclear medicine diagnostic procedure. Impurities may arise during preparation and storage of radiopharmaceuticals and will frequently modify organ distribution and specificity, possibly leading to an incorrect diagnosis of the patient's health. This review is a guide to radiochemical analytical principles for those who develop new short-lived radiopharmaceuticals. The applicability of some recently developed methods is contrasted with conventional techniques, and guidelines are suggested for predicting the best separatory mechanism to apply to a new radiochemical quality control problem. The selected method(s) should be sensitive, reproducible, separate all possible components without causing changes in sample composition, and preferably be convenient to perform.