A homogeneous liquid reference material for monitoring the quality and reproducibility of in situ cosmogenic 10Be and 26Al analyses

Abstract

Analysis of the in situ produced cosmogenic nuclides 10Be and 26Al has been used for several decades to study Earth surface processes; yet, no reference material has been widely adopted and used by the community to ensure the quality and comparability of sample preparation and isotopic analyses. Such a reference material could facilitate inter-laboratory comparison and serve as a benchmark for quantifying the accuracy, precision, and long-term reproducibility of terrestrial cosmogenic nuclide analyses. Here, we describe a liquid reference material, UVM-A, which is freely available to the community. We created four liters of solution by dissolving CRONUS-A granular reference material [1], and spiking the solution with stable 9Be and 27Al, yielding a solution containing 236.7 ± 0.6 μg g−1 Be and 932.6 ± 1.6 μg g−1 Al (average, 1SD). Initial analyses of UVM-A indicate that the nuclide ratios of the reference material (10Be/9Be 1.43 ± 0.02 × 10−13; 26Al/27Al 4.44 ± 0.05 × 10−13; average, standard error) are similar to those of late-glacial exposure samples, are tightly clustered, and match the nuclide concentrations expected from the CRONUS-A quartz used to prepare the reference material. Use of this reference material will help to quantify uncertainty in cosmogenic exposure ages, burial ages, and erosion rates resulting from sample preparation and isotopic analysis.