Rapid analysis of ⁹⁰Sr in cattle bone and tooth samples by inductively coupled plasma mass spectrometry

Rapid analysis of 90Sr in bone and tooth samples of cattle was achieved by inductively coupled plasma mass spectrometry (ICP-MS) coupled with mass-shift and solid-phase extraction techniques. The mass-shift technique with the O2 reaction mode of ICP-MS was applied to the mass shift of isobaric element 90Zr, effectively removing its interference. The solid-phase extraction technique using a Sr resin, which is a polymeric resin supported by 4,4′(5′)-bis-t-butylcyclohexano-18-crown-6, quantitatively separated 90Sr from the interfering matrix elements and isobars in the bone and tooth samples. The activity concentrations determined by ICP-MS were comparable with those determined by the conventional radiometric method. However, the limit of detection in the ICP-MS measurement of 0.1 g samples was lower than that in the radioactivity measurement. The analytical time of the ICP-MS method was shortened from 20 days to 11 h, compared with the radiometric method. Therefore, the ICP-MS method can be a rapid and useful procedure for determination of 90Sr in small bone and tooth samples taken from terrestrial animals.