A High-Throughput Method for the Conversion of CO2 Obtained from Biochemical Samples to Graphite in Septa-Sealed Vials for Quantification of 14C via Accelerator Mass Spectrometry

The growth of accelerator mass spectrometry as a tool for quantitative isotope ratio analysis in the biosciences necessitates high-throughput sample preparation. A method has been developed to convert CO2 obtained from carbonaceous samples to solid graphite for highly sensitive and precise 14C quantification. Septa-sealed vials are used along with commercially available disposable materials, eliminating sample cross contamination, minimizing complex handling, and keeping per sample costs low. Samples containing between 0.25 and 10 mg of total carbon can be reduced to graphite in ~4 h in routine operation. Approximately 150 samples per 8-h day can be prepared by a single technician.