Optimisation of enrichment methods and evaluation of errors for high sensitivity measurement of ²²²Rn in natural waters

Radon-222 (²²²Rn) is increasingly being used to measure and map groundwater-surface water interactions in natural waters. However, the direct measurement, without prior enrichment of ²²²Rn, allowing for a lower limit of detection of 0.2 BqL⁻¹ is not sensitive enough to study ²²²Rn concentrations in the water close to or below 0.2 BqL⁻¹. ²²²Rn enrichment prior to measurement, to increase the number of measured ²²²Rn decays, enables for improved measurement sensitivity. Here we show the influence of every parameter of ²²²Rn measurement and enrichment to enable optimisation of the ²²²Rn measurement.