2018 International Radon Symposium and Trade Show

Quality Assurance in Measurement of Radon in Water By Liquid Scintillation Counting
 Uttam Saha 1, Leticia Sonon 1, Pamela Turner 2, Dana Lynch 3, and Gabrielle Dean 2
1 Agricultural and Environmental Services Laboratories, College of Agricultural and Environmental Sciences, The University of Georgia, Athens, GA, USA.
2 Department of Financial Planning, Housing and Consumer Economics, College of Family and Consumer Sciences, The University of Georgia, Athens, GA, USA.
3 Family and Consumer Sciences Agent, The University of Georgia Cooperative Extension, Monroe County Extension, Athens, GA, USA.
sahau@uga.edu
Abstract
Our papers in 2016 and 2017 Symposia discussed optimum sampling and analysis methods for radon in water. This presentation discusses quality assurance. The counting efficiencies of multiple liquid radium standards purchased from a commercial manufacturer produced inconsistent and unacceptable counting efficiencies; thus, their use in the analysis appeared questionable. Duplicate analysis of radon in 142 well water samples mostly yielded relative percentage deviation (RPD) ≤15 and seldom >15. However, >15 RPD was associated with the presence of an air bubble in one of the duplicate samples. Repeated analyses of two radon proficiency-test samples, regenerated at 40 to 60 day intervals over a period of two years, consistently yielded acceptable precision (based on the duplicate analyses) and accuracy (closeness to the theoretical radon concentration). Thus, a proficiency testing for radon in water is a valid and valuable option, and should be part of programs that analyze radon in water.