Rapid determination of technetium-99 by electrothermal vaporization-inductively coupled plasma-mass spectrometry with sodium chlorate and nitric acid as modifiers Original Research Article

An electrothermal vaporization-inductively coupled plasma-mass spectrometric (ETV-ICP-MS) method based on the suppression of ruthenium by using nitric acid and sodium chlorate as modifiers has been developed for determination of 99Tc in the presence of ruthenium. A 1000 fold excess of Ru in the presence of 100 pg/ml 99Tc resulted in an 4% signal increase in the signal of mass 99 amu. Both nitric acid and sodium chlorate act in this case as chemical modifiers, rather than simply as mere physical carriers. The recommended concentrations of nitric acid and sodium chlorate are 1 and 0.7%, respectively. The limit of detection of 99Tc is 1.4 pg/ml (0.9 mBq/ml) and 28 fg (18 μBq) absolute. The concentration of 99Tc in three spiked samples with various matrices was determined.