The Comparison of Automated and Manual Preparation of ¹⁴C Graphite Targets for Accelerator Mass Spectrometry

The precision of radiocarbon (¹⁴C) dating techniques depends on the quality of graphite target preparation. This study systematically evaluated the performance differences between the automated graphitization system (AGE3) and vacuum system (VAC) in graphite target preparation. The results showed that the absolute deviation of the IAEA standards prepared by the AGE3 was 0.03%-0.17% pMC, superior to the VAC system. Both systems exhibited consistency in OX-Ⅱ and PHA preparations, and the coefficient of variation (CV) of the two systems is 0.27% for sediment samples and CV=0.12%-2.33% for groundwater samples. AGE3 can process more than 14 samples per day, which is over twice the efficiency of VAC, making it suitable for high-throughput sample preparation. Optimized pretreatment methods had lowered the minimum measurable carbon mass to 0.3 mg C in both systems, fulfilling the analytical requirements for trace-level precious samples. The AGE3 system is user-friendly, featuring a fixed graphitization program. In contrast, the VAC system is highly flexible with a controllable graphitization process. Both systems produce high-quality graphite targets with excellent precision and stability, providing efficient technical solutions for research in sediment and groundwater dating, paleoclimate reconstruction and other studies.