Which is the best (9)Be carrier for (10)Be/(9)Be accelerator mass spectrometry?

Commercial (9)Be solutions used for chemical preparation of samples for accelerator mass spectrometry contain the cosmogenic long-lived radionuclide (10)Be at elevated but different (10)Be/(9)Be levels. Within a systematic study of recently produced solutions, comparison to published data and new data on customised solutions from minerals, we recommend - if no customised solution is available - the (9)Be solutions from Australian Chemical Reagents (ACR) or from LGC. They contain (10)Be/(9)Be at the 3.4 × 10(−15) level, which is still suitable for the majority of Earth science applications, compared to customised solutions at the 10(−16) level for lowest-level studies. Commercial solutions from Scharlab having different lot numbers, i.e. an identification number assigned to a particular lot of material from a single manufacturer, vary in (10)Be/(9)Be by up to a factor of nine. Hence, it seems an advisable strategy to buy a bigger quantity of a single production batch (such as 10 × 100 ml bottles of (9)Be at 1 g l(−1)) and have them tested once at any AMS facility before first use. • The best (9)Be carrier for low-level (10)Be/(9)Be applications is a customised one from minerals like phenakite. • The best (9)Be carriers for medium- and high-level (10)Be/(9)Be applications are currently from Australian Chemical Reagents (ACR) or from LGC. • As (9)Be carriers from Scharlab of different batches (LOT) contain (10)Be/(9)Be at different levels, it is advisable to buy a bigger number of bottles of the same LOT of commercial carriers after being identified to have reasonably low isotope ratios.