Measuring 7Be, 10Be and 210Pb in rain
- Very weakly acidified de-ionised water and 9Be carrier are added to the collector at the beginning of the sampling period, typically one month.
- When necessary, more de-ionised water is added to compensate for evaporation thus avoiding dry sample being blown from the collector by wind.
- The collected water is filtered and passed through an ion-exchange column to absorb the Be which is then eluted with 4M HCl.
- Excess acid is evaporated, Be recovered as hydroxide and the 7Be measured by gamma spectrometry.
- A sub-sample is taken for chemical yield determination and the remainder processed for 10Be analysis by AMS.
- The residue from the filters is processed separately.
- If required, 210Pb can also be measured and an exchange service is available for ion-exchange columns and filters.