Automatic graphitization system for radiocarbon analysis by accelerator mass spectrometry

使用加速器质谱法（AMS）进行放射性碳分析（14C）需要一个自动石墨化系统。石墨化系统通过燃烧有机样品或用酸水解无机样品，将有机和无机样品（例如沉积物、植物、骨骼、贻贝、水）中所含的碳转化为二氧化碳。然后，二氧化碳通过氦气流转移到分子筛上。通过加热分子筛材料，二氧化碳被释放到所谓的反应器中，在加入氢和加热后，它被还原为单质碳。然后在AMS中测定14C浓度。该系统的优点是它是全自动操作的，这意味着高样品吞吐量是可能的。此外，与其他方法相比，不需要液氮来浓缩二氧化碳。申请该系统后，可以处理正在进行和计划中的项目中需要处理的所有类型的样品。目前情况并非如此。确定年龄对于回答地球科学、考古学、艺术史和其他问题很重要。14C分析还提供了关于碳循环过程的信息，如碳的转化率或不同碳源的比例及其年龄和/或来源，这些信息用于正在进行的关于北极永久冻土融化中碳释放的研究项目。此外，14C分析是科隆大学正在进行的两个CRC 806和1211的重要方法，也应该用于下面给出的正在进行和计划中的项目。

An automatic graphitization system is required for performing radiocarbon analyzes (14C) using accelerator mass spectrometry (AMS). The graphitization system converts carbon contained in organic and inorganic samples (e.g., sediment, plants, bones, mussels, water) into carbon dioxide by combusting organic samples or by hydrolyzing inorganic samples with acid. The carbon dioxide is then transferred by a helium stream to a molecular sieve. By heating the molecular sieve material, the carbon dioxide is released into so-called reactors, where it is reduced to elemental carbon after adding hydrogen and by applying heat. The 14C concentration is then determined in the AMS.The advantage of the system is that it is operated fully automatically, which means that a high sample throughput is possible. In addition, no liquid nitrogen is required to concentrate the carbon dioxide as with alternative methods. With the system applied for, all types of samples that are to be processed in ongoing and planned projects can be processed. This is currently not the case.Age determinations are important for answering geoscientific, archaeological, art historical and other questions. 14C analysis also provides information about carbon cycle processes such as conversion rates of carbon or proportions of different carbon sources and their age and/or origin, which is used in ongoing research projects on carbon release from thawing, arctic permafrost soils. In addition, 14C analyzes are an important method in the two ongoing CRC's 806 and 1211 at the University of Cologne and should also be used in the ongoing and planned projects given below.