Analysis of 85Kr: a comparison at the 10 -14 level using micro-liter samples

Area of Science:

• Environmental Science
• Nuclear Physics
• Analytical Chemistry

Background:

• Atmospheric Krypton-85 (85Kr) abundance has significantly increased due to nuclear activities.
• 85Kr's long half-life (10.76 years) makes it a valuable tracer for environmental samples like air, groundwater, and ice.
• Accurate measurement of rare isotopes like 85Kr is crucial for environmental monitoring.

Purpose of the Study:

• To assess the reliability and reproducibility of Atom Trap Trace Analysis (ATTA) for quantifying 85Kr.
• To validate ATTA by comparing results from different international laboratories.
• To establish ATTA as a robust method for analyzing trace levels of 85Kr in environmental samples.

Main Methods:

• Atom Trap Trace Analysis (ATTA), an emerging technique for rare isotope analysis.
• Analysis of 12 environmental samples with 85Kr/Kr ratios ranging from 10(-13) to 10(-10).
• Independent measurements conducted in three distinct laboratories: one low-level counting lab (Bern) and two ATTA labs (Hefei and Argonne).

Main Results:

• The (85)Kr/Kr ratios measured by the three laboratories showed agreement within a 5% precision level.
• This inter-laboratory comparison demonstrates the consistency and reliability of the ATTA method.
• Successful quantification of 85Kr at trace isotopic abundance levels was achieved.

Conclusions:

• Atom Trap Trace Analysis (ATTA) is a reliable and reproducible method for measuring trace levels of Krypton-85.
• The study confirms the capability of ATTA to provide accurate isotopic abundance data for environmental monitoring.
• ATTA offers a powerful tool for tracing environmental samples using rare krypton isotopes.