Study on radiochemical analysis of 210Po in soil

210 Po is a natural radioactive nuclide, belonging to the uranium series decay product, with high toxicity alpha radiation characteristics, widely present in environmental media such as soil. It poses a potential internal radiation risk to human health, therefore accurate monitoring of 210 Po in soil is of great significance for public health and radiation environment regulation. At present, there is a lack of standardized analysis methods for 210 Po in soil media both domestically and internationally, resulting in inconsistent quality of monitoring data. Based on extensive literature research and multi institutional experimental verification, this study proposes a soil 210 Po analysis method that combines wet acid digestion and spontaneous deposition followed by alpha spectroscopy. The HNO 3  + HCl + HF (3:2:1) mixed acid system is used to optimize key parameters such as digestion temperature (160 °C), self deposition acidity (0.2–0.5 mol/L HCl), and ascorbic acid dosage (0.5 g). The method has been validated by 8 radiation monitoring institutions in China, showing a method detection limit (MDL) of 1.0 × 10 −3  Bq/g and a limit of quantification (LOQ) of 4.0 × 10 −3  Bq/g, a precision (RSD) of 2.5–14% and a spike recovery rate of 107–108% for method accuracy evaluation. It has good accuracy, repeatability, and universality, and is suitable for daily environmental monitoring needs.