Performance of graphite preparation at the IHEG-CAGS accelerator mass spectrometry 14C laboratory

In 2022, the Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences(IHEG-CAGS)established an accelerator mass spectrometry(AMS) 14C laboratory, equipped with a multi-element accelerator mass spectrometry-1 MV AMS(HVE), a manual vacuum line system(VAC), and an automated graphitization equipment(AGE3). This study evaluates the operational status of the newly established laboratory and its graphite target preparation capability. Tests conducted on standards and blank samples demonstrated that graphitization at the IHEG-CAGS AMS-14C laboratory are accurate, stable and precise. 14C results of reference materials and blank indicate: mean values and consensus values are consistent within the 1 σ error range; the background 14C value is 0.17±0.01 pMC, which 14C age is approximately 51 ka B.P.; the graphitization process shows no significant dependence on the 14C concentration of the sample. Results of this study provide essential guidance for high quality graphite preparation at the IHEG-CAGS AMS-14C laboratory. The graphitization process at the laboratory has been applied to various types of sample preparation including plants, soils, lake sediments and groundwater 14C dating. The excellent graphitization of this laboratory lays a solid foundation for obtaining reliable 14C age data in the future, and provides important technical support for developing of 14C dating technology in the fields of geology, hydrology, environment and archaeology.