Radiochemical quality control of 99mTc-labeled radiopharmaceuticals. Some daily practice guideliens.

Recognizing the fact that each nuclear medicine facility should be able to perform simple radiochemical quality tests on currently used radiopharmaceuticals, this study was undertaken to evaluate a number of radiochromatographic methods. No single ideal method exists to assess the radiochemical composition of 99mTc-labeled antimony sulphur colloid, sulphur colloid, iron ascorbate, citrate, human serum albumin, EHDP, macroaggregates, and microspheres. It is advisable to include thin layer chromatography with both NaCl and methylethylethylketone for the determination of free pertechnetate in each day's program. More detailed radiochemical analysis can be performed by combining these methods with paper chromatography, paper electrophoresis, and gel filtration. It seems reasonable to regard a constant radiochromatographic pattern as a measure for constant radiochemical quality. The four chromatographic tests lead to consistent results regarding the percentage of free pertechnetate in the radiopharmaceutical preparations. Quantitative analysis shows that the radiochemical purity for each radiopharmaceutical is unique for the chromatographic method used and needs to be defined when stated.