Abstract
Miniaturized chromatography systems have been used over the years with few problems; yet it is imperative that a standard procedure be scrupulously followed. Variation in proper radiochromatographic technique can result in false radiopurity estimations. The two most frequent causes of these errors are simple procedural mistakes: (1) counting the strips too close to the gamma scintillation detector, thus exceeding count rate capabilities; and (2) spotting the origin below the initial solvent level in developing vials. Improper technique can result in large overestimations of impurity levels in Tc-99m-labeled radiopharmaceuticals.