Optimization of Sealed Tube Graphitization Method for Environmental C-14 Studies Using MICADAS

The original sealed tube zinc reduction graphitization process was first developed for rapid low-precision measurements of biomedical tracer samples and later also applied for high precision measurements of not too old samples. In this study we tested the MICADAS (mini radiocarbon dating system [1]) radiocarbon measurements of targets prepared by sealed tube graphitization process. We found the optimal iron catalyst and reagents (TiH2 and Zn) amount whereby we can reach a relatively low background level, and minimized the overall δ13C fractionation during the graphitization. Repeated measurements of normalization standards and real samples with known 14C activities were very well reproduced. Finally, we demonstrated the applicability of the sealed tube graphitization on real environmental samples covering a wide range of 14C concentrations.