Evaluation of ¹⁴C/¹²C ratio measurements using accelerator mass spectrometry with standard materials under different...

In this study, an evaluation of carbon-beam tuning and ¹⁴C/¹²C ratio measurements is performed to validate the graphitization process in the pre-processing procedure employed at the accelerator mass spectrometry (AMS) facility of Dongguk University in Korea. The AMS isotopic ratio data are analyzed for samples subjected to three different graphitization conditions: (1) the entire process including Fe catalyst pre-heating with a high vacuum, (2) a high vacuum without pre-heating, and (3) a low vacuum without pre-heating. High-quality isotopic ratio measurements are achieved under these conditions. The measured mean isotopic ratio values for the background samples are almost equivalent to the different graphitization condition samples, with a difference in the order of 10^-16. Therefore, conducting measurements with or without Fe catalyst pre-heating or high vacuum conditions is equally viable. Furthermore, the simplification of the graphitization process steps reduces the processing time required to produce five samples from 8 to 4 h, thereby enhancing the daily sample throughput by a factor of two, without compromising data quality.