Optimization of operating conditions for improved precision of zirconium and hafnium isotope ratio measurement by inductively coupled plasma mass spectrometry (ICP-MS)

The optimal instrument operating parameters (IOPs) for improving the precision of Zr and Hf isotope ratio measurements by inductively coupled plasma mass spectrometry (ICP-MS) were investigated, as an initial step towards improving precision in the determination of Zr and Hf abundancies in samples with low concentrations of these elements by isotope dilution ICP-MS. By optimizing IOPs, it is not necessary to correct for potential interferences from rare earth element oxides, without sacrificing precision and accuracy of isotope ratio measurement. Precision and mass bias are insensitive to the concentration of Zr and Hf over the range of sub-ppb to ppm. An overall precision of 0.2-0.6% relative standard deviation can be achieved for Zr and Hf isotope ratio measurement, and can be maintained over 7 h periods. (author)