Determination of <sup>210</sup>Po in marine organism by pressure tank digestion and alpha spectrometry

<bold>Background</bold>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.<bold>Purpose</bold>This study aims to develop a method for the determination of ²¹⁰Po in marine organism by pressure tank digestion and alpha spectrometry.<bold>Methods</bold>Firstly marine organism samples, with the addition of a ²⁰⁹Po yield tracer, were digested by pressure tank method. ²¹⁰Po was then spontaneously plated onto nickel disk in hydrochloric acid system and measured with alpha spectrometer. Thereafter, the experimental conditions were optimized for both digestion (acid selection, acid dosage, temperature, duration) and auto-deposition (temperature, time, hydrochloric acid (HCl) concentration, solution volume, types of metallic discs). Finally, aforementionted method was validated by the analysis of a certified reference material IAEA-414.<bold>Results</bold>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.<bold>Conclusions</bold>Validation results demonstrate that the method proposed in this study is simple, rapid and accurate, and can be applied to measurement of ²¹⁰Po in marine organism.