Inductively coupled plasma mass spectrometry using isotope dilution (ID-ICP-MS) with liquid-liquid extraction was used for determining ultra-trace tellurium (Te) in steels to improve the sensitivity, accuracy, and precision of the analysis. Single quadrupole-type ICP-MS cannot be used to determine the trace amount of Te because of the contribution of mass spectrometric interference by Xe. To overcome this, tandem mass-filter-type ICP-MS (ICP-MS/MS) was used to determine Te. A pretreatment by liquid-liquid extraction was also employed to compensate for the decrease in the signal intensity due to the use of ICP-MS/MS. The relative standard deviations of the resulting abundances, defined by repeated analysis from separated three steel samples, were <1.3%. Furthermore, the determined values of Te in standard reference materials were close to the reference values. Thus, the developed determination method is useful for the analysis of ultra-trace Te in steels.
Keywords: Inductively coupled plasma mass spectrometry; isotope dilution; steel; tellurium.