RT Journal Article SR Electronic T1 Rapid Determination of the Radiochemical Purity of 99mTc-Antimony Trisulfide Colloid Prepared by Standard and Alternative Heating Methods JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 174 OP 178 VO 34 IS 3 A1 Douglas R. Smyth YR 2006 UL http://tech.snmjournals.org/content/34/3/174.abstract AB The purpose of this study was to validate a rapid quality control method for the lymphoscintigraphic tracer 99mTc-antimony trisulfide colloid (99mTc-ATC). Methods: ATC was labeled with 99mTc according to the manufacturer's instructions as well as by alternative heating conditions designed to provide a range of percentages of radiochemical purity (RCP): the tracer was prepared in a dry block heater with heating cavities of different sizes, the temperature of the heating block was varied from 70°C to 115°C, or the duration of heating was varied from 15 to 35 min. Anion-exchange minicolumns were trialled to separate any 99mTc-pertechnetate impurity from 99mTc-ATC with physiologic saline as the eluent. Quality control results were compared with the results from the manufacturer's recommended method, which uses an instant thin-layer chromatography (ITLC) strip with saline as the migrating solution. Results: The quality control results obtained with a cartridge method in 2−3 min compared favorably with those obtained with the ITLC method with saline when the tracer was prepared by heating at 115°C in a dry block heater for 35 min (RCPs, 99.4% ± 0.3% [mean ± SD] and 99.2% ± 0.3%, respectively; n = 25). The cartridge and ITLC quality control results also were in excellent agreement (correlation coefficient, 0.99) over a range of RCPs (80%–100%). An alternative anion-exchange cartridge that was tested in this study was not suitable for assaying the RCP of 99mTc-ATC because of the complete retention of 99mTc-pertechnetate on the sorbent. Conclusion: Compared with the established ITLC method, the cartridge quality control method tested in this study is rapid and provides a reliable assessment of the RCP of 99mTc-ATC. For the preparation of 99mTc-ATC, a dry block heater can be successfully substituted for a boiling water bath and is recommended for heating at high altitudes.