Discussion on the Key Factors of Abundance Ratios About Zn Isotope Measurement

The application of Zn isotope analysis is well known in geochemistry and diet study. An inter-lab comparison of five samples with isotopic ratio covering from 0.02 to 1500 was organized in order to develop measurement ability and keep consistency of the results of isotopic ratios measurement among the participants. Multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) and multicollector thermal ionization mass spectrometry (MC-TIMS) were used. For MC-ICP-MS, blank-corrected and blank-no corrected results were submitted. For MC-TIMS, total evaporation method (TE) was applied to the samples while a certified reference material IRMM3702 was analyzed together. All the results showed that the uncertainties were 1.29%-0.03% for 64Zn/66Zn, and the uncertainty was obviously relative to isotopic abundances. The blank-corrected and blank-no corrected and the influence of blank and non-linear of K factor of mass discrimination for MC-ICP-MS were convinced of contributing to the unsatisfied uncertainties.