Electrolytic enrichment method for tritium determination in the Arctic Ocean using liquid scintillation counter

摘要

A method of measuring the tritium in seawater based on electrolytic enrichment and ultra-low background liquid scintillation counting techniques was established.The different factors influencing the detection limit were studied,including the counting time,the electrolytic volume of the seawater samples,the selection of background water,scintillation solution and their ratio.After optimizing the parameters and electrolyzing 350 mL volume of samples,the detection limit of the method was as low as 0.10 Bq/L.In order to test the optimization of system for this method,of the 84 seawater samples collected from the Arctic Ocean we measured,92%were above the detection limit(the activity of this samples ranged from 0.10 Bq/L to 1.44 Bq/L with an average of(0.30±0.24)Bq/L).In future research,if we need to accurately measure the tritium activity in samples,the volume of the electrolytic samples will be increased to further reduce the minimum detectable activity.