Chemical procedure for Zn purification and double spike method for high precision measurement of Zn isotopes by MC-ICPMS

Quentin Amet, Caroline Fitoussi

International Journal of Mass Spectrometry
Available online 15 August 2020, 116413



• A new method of Zn isotope analysis by MC-ICPMS has been developed.
• This technique includes a new chemical protocol to separate Zn and the use of 64Zn–67Zn double spike.
• This new method allows the determination of Zn isotope composition in geochemical and cosmochemical sample with high precision and accuracy.”

“We have developed a new technique for Zn separation and high precision isotope measurement of geological and cosmochemical samples. The protocol includes sample digestion, chemical separation and purification with ion-exchange chromatography and a double spike isotopic measurement using a MC-ICPMS. An analytical precision of 0.02‰ (2SD) for 66Zn/64Zn was obtained by multiple measurements of a secondary standard (JMC-Lyon). In order to test the accuracy of our method, we analyzed the Zn isotopic composition of the geological reference materials BHVO-2, AGV-2, BIR-1, BCR-2 and JB-2, which are consistent with previous measurements from the literature. The measurements of geological reference standards show an external reproducibility ranging between 0.02 and 0.05‰ (2SD). This study provides a high precision and accuracy Zn isotope double spike technique for geological and cosmochemical rock samples, while requiring only 28 ng Zn per analysis, and is therefore suitable for the study of high temperature igneous or cosmochemical processes.”