The quantification of technetium in generator-derived pertechnetate using ICP-MS

Previous analytical methods employed to measure 99 Tc: 99 m Tc ratios in chromatographic 99 m Tc generators, derived from fission-based 99 Mo , were limited in monitoring the ratios in low activity generators, over the extent of their elution regimes. For regulatory purposes, ICP-MS was employed to measure total technetium in generator eluates down to a level of 200 pg ml −1 (200 ppt). Measured 99 Tc: 99 m Tc ratios compared very well with the theoretically computed values, ranging from 47:1 for a first elution of a generator with a long ingrowth time to 1.4:1 for the 17th elution of a generator with a short ingrowth time.