Radiocarbon Dating of Ancient Iron Artifacts by Accelerator Mass Spectrometry.

1977年加速器质谱法（AMS）的复兴是物理、化学、地质、地理等多学科领域的一个革命性事件。AMS技术已被应用于极少量样品的放射性碳定年。人类使用铁的历史是人类文明发展史上具有划时代意义的事件。在这方面，利用AMS技术对古代铁器文物进行断代具有重要意义。问题是如何在不污染现代碳的情况下提取铁样品中的碳。我们已经开发了两种技术来提取它。一种是干法：在一个封闭的系统中燃烧样品，然后收集二氧化碳。另一种是湿法：用含有化学试剂的溶液处理样品，从溶液中分离出碳单质或化合物。根据待测样品的性质，选择其中一种方法。通常，干法比湿法更有用。这两种方法均可用于高含碳量的试样，并在本实验室得到了准确的结果。碳含量较低的样品通常比其他样品更有价值，其处理是未来研究的一个主题。

Revival of Accelerator Mass Spetrometry (AMS) in 1977 was a revolutionary event in the fields of various disciplines : They include physics, chemistry, geology, geography etc. The AMS technique has been applied to radiocarbon dating of very small amouts of samples. History of the use of iron by man is a epoch-making event in the development of human civilization. In this respect, it is important to date ancient iron artifacts by the AMS technique. Theproblem is how to extract carbon in iron samples without the contamination of modern carbon. We have developed two techniques to extract it. One is a dry method : Buring of the sample in a closed system followed by the collection of carbon dioxide. The other is a wet method : The sample is treated with a solution containing chemical reagents and obtained carbon simple element or compound is separated from the solution. According to the property of the sample to be measured, we choose one of the methods. Usually, the dry method is more useful than the wet method. Either methpd can be applied to the samples containg high amount of carbon, and aocurate results are obtained in our laboratory. The processing of samples containig lesser carbon, which are often more valuable than the other samples, is a subject of future studies.