锌原子量的国际新标准

The New International Standard of Zinc Atomic Weight

化学元素的原子量是自然界的基本常数。原子量的概念对化学及相关学科的发展,起着基础性的推进作用。化学学科发展的两个理程碑:原子-分子学说和元素周期率,都是以原子量为基础。因此,各国化学家都十分重视它的测量和修正工作。原子量的测量已有180年的历史,其方法由最初的化学法、相对质谱法发展到目前的绝对质谱法,几经改进,测量值的不确定度有了明显提高,同时原子量的测量也反映一个国家的科学技术水平。

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