Development of the NBS beryllium isotopic standard reference material

The National Bureau of Standards, in conjunction with the Oak Ridge National Laboratory and the Accelerator Mass Spectrometry community, is in the process of developing a beryllium isotopic solution Standard Reference Material. The master /sup 10/Be//sup 9/Be solution was characterized isotopically by resonance-ionization and secondary-ion mass-spectrometric-based techniques, and radioactivity measurements were by liquid scintillation counting. The master solution was gravimetrically diluted with /sup 9/Be to a final /sup 10/Be//sup 9/Be atomic ratio of 3 x 10/sup -11/. The preliminary data indicate a half life for /sup 10/Be of 1.3 million years, and AMS measurements are within 10% of the known beryllium isotopic ratio