Seven 99Mo/99mTc generators (using fission 99Mo) obtained from seven different manufacturers were studied in 1984 and 1985 to test the quality of the eluates. We present the findings concerning the elution efficiency, radionuclide purity, 99Mo breakthrough, radiochemical purity, pH, and aluminium content of the eluates. One generator was overloaded with 99Mo by about 40%, while one generator had 99mTc yields of only about 80%. The eluates generally (although with some exceptions) exhibited a high and satisfactory radionuclidic purity and good radiochemical purity. The low-level determination of 99Mo breakthrough using a commercially available dose calibrator with a 99Mo assay shield indicated a misleadingly high 99Mo content. All of the eluates had pH values of between 5.0 and 5.5, and the aluminium content was always below the detection limit of 1 microgram per milliliter of eluate. The generators performed well and proved their capability of functioning as reliable sources of sodium pertechnetate Tc99m. In all cases, the pertechnetate produced met the requirements of the European Pharmacopeia.

ZusammenfassungZehn in der klinischen Routine häufig verwendete Radiopharmaka wurden auf ihre radiochemische Reinheit untersucht. Dabei angewandte Analysenmethoden waren die Dünnschichtchromatographie, die Papierchromatographie und die Elektrophorese. Die Messung der Aktivitäten der getrennten Komponenten erfolgte in einem Gamma-Probenwechsler. Die vermutliche chemische Identität der radiochemischen Verunreinigungen wurde durch Vergleich der Untersuchungsergebnisse mit Daten aus der Literatur ermittelt. Die radiochemische Reinheit unterschritt bei allen untersuchten Radiopharmaka nicht den vom Hersteller angegebenen Wert und erfüllte auch die Anforderungen des Europäischen Arzneibuches, soweit die Arzneimittel dort verzeichnet sind.

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Quality was controlled of seven different 99Mo/99mTc generators sold in the Federal Republic of Germany, which were all loaded with fission molybdenum. Aim of the work was to test the 99mTc eluates for their radionuclidic and radiochemical purity. Furthermore, the 99Mo content of the aluminium oxide column was measured. Determination of the elution efficiency, measurement of the pH-value of the eluate as well as a test to detect soluble aluminium in the eluate were also performed. In addition to the chemical and physical examinations, application, quality of accessories and their practicability were tested at all generators. The methods of analysis chosen were, among others, gamma spectrometry and thin-layer chromatography; the measuring methods were a site-sensitive proportional counter (measurement of the distribution of radioactivity of the chromatograms) and atomic absorption spectrometry (AI content of the eluates). The quality control of the 99mTc eluates had satisfying results. The eluates showed – with one exception – high and sufficient radionuclidic purity and very good radiochemical purity. A considerable overload of the columns with 99Mo at the time of reference was not found. The elution yields with values between 85 and 122% were in good agreement with the requirements. All eluates had pH-values between 5.0 and 6.5, and an aluminium content below 1 μg/ml. The generators had good performance and proved generally to be a reliable source of 99mTc-pertechnetate. The application was safe and, with some exceptions, fulfilled the requirements.