Absolute Isotopic Abundance Ratio And Atomic Weight Of a Reference Sample of Gallium
L A Machlan1, J W Gramlich1, L J Powell1
1National Bureau of Standards, Gaithersburg, MD 20899.
Summary
Researchers precisely measured the gallium isotopic abundance ratio using mass spectrometry. This study provides an accurate 69Ga/71Ga ratio and atomic weight for gallium standard reference material.
Area of Science:
- Analytical Chemistry
- Atomic Physics
- Isotope Geochemistry
Background:
- Accurate isotopic abundance ratios are crucial for elemental metrology.
- Gallium's isotopic composition is essential for various scientific and industrial applications.
- Previous measurements may have lacked the required precision for a definitive standard.
Purpose of the Study:
- To determine the absolute isotopic abundance ratio of 69Ga to 71Ga in a reference gallium sample.
- To establish a precise atomic weight for gallium based on its isotopic composition.
- To provide a reliable standard for future gallium isotope research.
Main Methods:
- Thermal ionization mass spectrometry (TIMS) was employed for high-precision measurements.
- Calibration of mass spectrometers using samples of known isotopic composition.
- Preparation of calibration standards from nearly isotopically pure separated gallium isotopes.
Main Results:
- The absolute 69Ga/71Ga ratio was determined to be 1.50676±0.00039.
- Atom percent values: 69Ga = 60.1079±0.0062% and 71Ga = 39.8921±0.0062%.
- Calculated atomic weight of gallium: 69.72307±0.00013.
Conclusions:
- The study provides a highly accurate absolute isotopic abundance ratio for gallium.
- The established atomic weight serves as a precise reference value.
- These findings enhance the metrological foundation for gallium measurements.
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