We conducted a preliminary test of the coupled system of an elemental analyzer and the automated graphitization equipment Ionplus AGE3 (EA-AGE3 method) for accelerator mass spectrometry radiocarbon (AMS 14C) measurements of CaCO3 samples, by comparing with the conventional method where the samples are hydrolyzed in phosphoric acid and resulting CO2 gas is manually graphitized in a vacuum line (HPA method). The samples used in the test were the IAEA C2 travertine, fossil and modern corals from the Ryukyu Islands and the Ogasawara Islands, respectively (both are located in the northwestern subtropical Pacific). Results indicate that, relative to the HPA method, the EA-AGE3 method tends to cause an increase of ~0.4–0.5 pMC with more widely scattered data. This is presumably due to 14C contamination in the EA (the most likely cause seems to be a memory effect of 14C); this effect could be reduced by careful optimization of conditions and procedures in the EA process. The 14C data of pre-bomb annual bands (1931–1949 AD) in the modern Ogasawara coral obtained by the HPA method were used to estimate the marine reservoir 14C-age correction (ΔR) of this region; it ranges from –109 yr to –28 yr with the mean value with standard deviation of –81 ± 29 yr.

中文翻译：

---

EA-AGE3 系统的初步测试在小笠原群岛，西北副热带太平洋的 CaCO3 样品的 14C 测量和基于珊瑚的海洋储层校正估计

我们对元素分析仪和自动石墨化设备 Ionplus AGE3（EA-AGE3 方法）的耦合系统进行了初步测试，用于加速器质谱放射性碳（AMS14C) CaCO 的测量3样品，通过与在磷酸中水解样品并产生 CO 的传统方法进行比较2气体在真空管线中手动石墨化（HPA 方法）。测试中使用的样本分别是来自琉球群岛和小笠原群岛的国际原子能机构 C2 钙华、化石和现代珊瑚（均位于亚热带西北部）。结果表明，相对于 HPA 方法，EA-AGE3 方法往往会导致约 0.4-0.5 pMC 的增加，数据更分散。这大概是由于14EA 中的 C 污染（最可能的原因似乎是14C）; 通过仔细优化 EA 过程中的条件和程序，可以减少这种影响。这14使用 HPA 方法获得的现代小笠原珊瑚中炸弹前年带（公元 1931-1949 年）的 C 数据用于估计海洋储层14该区域的C-age校正（ΔR）；它的范围从–109 岁到–28 岁，平均值为–81 ± 29 岁。