Innovative Determination of Zinc Isotope Ratios in Geological Reference Materials: A Combined Precipitation and Anion Exchange Resin Method by MC-ICP-MS

Advancements in Zn isotope analytical methods and their widespread application in geosciences underscore the importance of the purification process in isotopic measurements.Efficient purification of Zn, which involves separating Zn from matrix elements, is essential for accurately determining Zn isotopic compositions.This study proposes an optimized purification method that combines precipitation and a chromatographic procedure, significantly enhancing the purification efficiency.Using the established purification process, nine widely available geological-certified reference materials with known Zn isotopic compositions yield 66 Zn values that are in agreement with most previously published data within two standard deviations (2s) of repeat measurements.In addition, the effects of the presence of matrix elements have been evaluated using Neptune Plus MC-ICP-MS in a wet plasma mode.The average 66 Zn value of the multi-elemental Zn standard GSB-1, prepared by adopting GSB with different matrix elements, demonstrates good consistency with the long-term measured value of the pure GSB-Zn solution after precipitation and chromatographic separation.This enhanced purification protocol for Zn isotope measurement applies to a diverse range of geological samples and reduces the time and chemical reagents required for purification compared to conventional methods.