Low-level tritium measurements in freshwater and seawater samples.

The aim of this study was to test two potential tritium determination methods (with and without electrolysis enrichment) suitable for low-level measurements. Both methodologies were applied to water samples from the Baltic Sea and ten Polish rivers providing new data on tritium activity concentration. Optimization steps carried out to the standard method lowered minimum detectable activity concentration (MDC) from 3.1 to 1.8 Bq L^–1 (at 95% confidence level) enabling to apply it to environmental water samples. However, electrolytic enrichment method of MDC of 0.20 Bq L^–1 provided more accurate results for tritium activity concentration in surface waters. [ABSTRACT FROM AUTHOR]