The New International Standard of Zinc Atomic Weight

Finnigan MAT-261 mass spectrometer was calibrated by gravimetric synthetic mixture samples from highly enriched isotopes of zinc in the form of oxides of defined purity. The calibrated mass spectrometer was used to measure the isotopic abundances of nature zinc samples. The absolute isotopic abundances of the Terrestrial samples were get as 48. 27(21 ) at. % 64Zn, 27. 89(5) at. % 66Zn, 4.10(1) at. % 67Zn. 19.02(8) at. % 68Zn, and 0.63(1) at. % 70Zn. The measured atomic-weight of zinc is 65.4087(63) with an uncertainty gived on the basis of 95% confidence