New Method for the Combustion of Samples for Radiocarbon Dating

Abstract

COMBUSTION to carbon dioxide is part of the preparation of most samples for radiocarbon dating. The procedures so far adopted by dating laboratories for this process have followed the example set by Libby¹, and are based on the classical technique of organic combustion analysis in which the sample is burned in a stream of oxygen in a tube furnace. Variations are chiefly in the design of the furnace and in methods of subsequent purification of the carbon dioxide. Satisfactory combustion is usually critically dependent on the rate of gas flow, and the process is time consuming, for it requires constant attention on the part of the operator over a period of 1–2 h for an average sample. Moreover, there are often difficulties in dealing with certain types of sample, particularly bone and antler where the presence of significant quantities of oxides of nitrogen and sulphur in the combustion products lead to problems in the subsequent purification of the carbon dioxide, especially when it is required for filling a proportional counter.