Preparing Be carrier solutions with low
10Be/
9Be ratios is essential for the applications of in-situ-produced cosmogenic
10Be in geochronology. This is because commercially available Be carriers are non-negligibly contaminated by
10Be. Recently, in-house Be carriers have been successfully applied to samples that contain small amounts of in-situ-produced
10Be. The first step in preparing in-house Be carriers is selecting suitable Be-bearing minerals that contain less
10Be. Here, we present a simple method for selecting appropriate raw minerals for in-house Be carriers. That is, measuring the
10Be/
9Be ratios of Be-bearing minerals by direct Cs sputtering. Analyses of the
10Be/
9Be ratios of phenakite (Be
2SiO
4) and beryl (Be
3Al
2Si
6O
18) obtained from a mineral collection at the Geological Survey of Japan indicate that phenakite generally contains more
10B, interfering isobar of
10Be, than beryl. In addition to the necessity of finding raw materials that contain low
10Be, our results indicate that it is preferable to select a starting material with a low B concentration. Fragments of Be-bearing minerals from target samples were directly packed, and showed effective beam currents. Therefore, we anticipate that the direct packing method can also potentially be used to measure
10Be in Be-bearing minerals for geological applications. The measurement background of accelerator mass spectrometry was evaluated using a B-removed Be carrier solution. While B is partly adhered to hydroxide gel, we demonstrate that the hydroxide gel wash reduces B in a Be carrier solution. To highlight the
10Be/
9Be ratios of Be-bearing minerals against commercially available Be solutions, we also investigated the
10Be/
9Be ratios of commercially available Be solutions.
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