Study on the Influencing Factors of Gross α and Gross β Radioactivity in Aerosols Measured by Ashing Method

To increase the reproducibility and comparability of the gross α and gross β radioactivity measurements in environmental aerosols, this paper conducted a study on the influencing factors based on ashing method. The influence of factors such as sample equilibrium time, ashing temperature, ashing time, and sample mass on the experimental results was obtained through experimental measurements, and the detection limit, precision, and accuracy of the measurement method were verified. The results indicate that the sample placement time directly affects the measurement results of the gross α and gross β radioactivity in aerosols. With the extension of placement time, the gross α and gross β counting rate rapidly decrease in the first 3 days, and remain basically constant after 120 hours and 100 hours, respectively. The ashing temperature should not exceed 400℃. For the gross α and gross β in aerosol samples with a volume of 10000 m³, the detection lower limit of this method was 1.6 μBq/m³ for gross α radioactivity and 0.7 μBq/m³gross β radioactivity. The maximum precision values of the measurement methods for the gross α and gross β in aerosols are 16.7% and 11.4%, respectively, with spiked recovery rates greater than 89.0%. The results show that the ashing method can be used to measure the gross α and gross β radioactivity concentrations in environmental aerosols.