Determination of [99]Tc in urine by isotope dilution inductively coupled plasma mass spectrometry (ID/ICP-MS)

A method for the determination of ⁹⁹Tc in urine employing isotope dilution inductively coupled plasma mass spectrometry (ID/ICP-MS) was developed. In this procedure, the urine sample was spiked with a known amount of ⁹⁷Tc and digested using peroxide and nitric acid. Isobaric interferents, ⁹⁷Mo and ⁹⁹Ru, were removed using extraction chromatography. Mass to charge ratios of 95, 97, 99 and 102 were monitored for quantitating the concentration of ⁹⁹Tc in the samples. Measurements made at the 10^-9 M level for ⁹⁹Tc had with an average relative error of 4% for a known concentration, an average relative standard deviation of 3% for twelve runs, and a detection limit of 1.1 x 10^-11 M for 3 s.