Determination of 210Po in marine organism by pressure tank digestion and Alpha spectrometry

[Background] 210Po in seafood is the main source of the total internal irradiation dose received by the population, and it is particularly important to accurately determine the activity concentration of 210Po in marine organisms. [Purpose] This study aims to develop a method for the determination of 210Po in marine organism by pressure tank digestion and Alpha spectrometry. [Methods] Sample, with the addition of a 209Po yield tracer, was digested by pressure tank method. 210Po was then spontaneously plated onto nickel disk in hydrochloric acid system and measured with α spectrometer. The experimental conditions were optimized for both digestion (acid selection, acid dosage, temperature, duration) and auto-deposition (temperature, time, HCl concentration, solution volume, types of metallic discs). The proposed method was validated by the analysis of a certified reference material IAEA-414. [Results] With the optimized conditions, the measurement results of 210Po in fish sample IAEA-414 fall within the confidence interval of 1.55～2.60 Bq·kg-1. The relative standard deviation is 9.0%. The recovery rates of 209Po tracer for reference samples vary from 92.9% to 98.6%. The detection limit of the method is 0.18 Bq·kg-1. [Conclusions] This method is simple, rapid and accurate, and can be applied to measurement of 210Po in marine organism.