Moore P W
J Nucl Med. 1984 Apr;25(4):499-502.
Technetium-99m solutions always contain Tc-99. The amount varies considerably, depending on production methods and conditions, generator performance, and the time between production or separation and use. There is increasing evidence that labeling and imaging with some radiopharmaceutical kits is adversely affected when the Tc-99 exceeds certain amounts. The sensitivity of particular kits to Tc-99 depends on the ligand, the amount of usable Sn2+, and the ratio of Tc to ligand. Although Tc-99 formed during production is removed in the final steps of generator manufacture, some may appear in early extractions in the solvent extraction process. If elution or extraction efficiencies are high, any Tc-99 is reduced within about two elutions to an insignificant level that is maintained in subsequent elutions. If efficiencies are below about 40%, however, the ratio of Tc-99 to Tc-99m increases with each elution.
锝-99m溶液总是含有锝-99。其含量变化很大，这取决于生产方法和条件、发生器性能以及生产或分离与使用之间的时间间隔。越来越多的证据表明，当锝-99超过一定量时，某些放射性药物试剂盒的标记和成像会受到不利影响。特定试剂盒对锝-99的敏感性取决于配体、可用二价锡的量以及锝与配体的比例。虽然生产过程中形成的锝-99在发生器制造的最后步骤中被去除，但在溶剂萃取过程的早期萃取中可能会出现一些。如果洗脱或萃取效率很高，任何锝-99在大约两次洗脱内会降低到一个微不足道的水平，并在随后的洗脱中保持。然而，如果效率低于约40%，锝-99与锝-99m的比例会随着每次洗脱而增加。
