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Published on: April 19, 2018
Characterization of the NIST seaweed Standard Reference Material
I Outola1, J Filliben, K G W Inn
1National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. iisa.outola@nist.gov
Summary
The National Institute of Standards and Technology developed a seaweed standard reference material using an international laboratory comparison. The median method proved best for calculating radionuclide values, providing certified data for 13 isotopes.
Area of Science:
- Environmental Science
- Analytical Chemistry
- Radiochemistry
Background:
- Accurate measurement of radionuclides in environmental samples is crucial for monitoring.
- Standard Reference Materials (SRMs) are essential for validating analytical methods and ensuring data comparability.
- Seaweed is a significant bioindicator for marine environmental radioactivity.
Purpose of the Study:
- To develop a certified Standard Reference Material (SRM) for seaweed.
- To establish reliable methods for determining radionuclide concentrations in seaweed.
- To provide certified and information values for a comprehensive suite of radionuclides.
Main Methods:
- An international interlaboratory comparison involving 24 participants from 16 countries.
- Evaluation of various statistical methods for calculating certified values of radionuclides.
- Application of the median method as the most representative technique for data analysis.
Main Results:
- Certified values were established for 13 radionuclides in the seaweed SRM.
- Information values were provided for an additional 15 radionuclides.
- Observed disequilibrium in both the uranium and thorium natural decay series.
Conclusions:
- The developed seaweed SRM is a valuable tool for interlaboratory comparisons and method validation.
- The median method is a robust statistical approach for determining radionuclide values in complex matrices.
- The results highlight the importance of considering natural decay series disequilibrium in environmental radioactivity assessments.
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