Radiocarbon dating of iron artefacts at the Erlangen AMS-facility

Radiocarbon dating of iron samples is, in spite of partially promising attempts in the last decades, still no established standard procedure. One of the main problems in preparing iron is the low carbon content which makes the needed sample size too big for some sample combustion systems. Also the metallic character of the samples complicates sample combustion or oxidation. This required in most cases an own preparation line only for iron samples. To avoid this problem two different ways are being followed at the Erlangen AMS-facility. One is direct sputtering of the unprocessed iron sample in the ion source. The other is the complete extraction of carbon from the iron sample and dating of the carbonaceous residue. First results from archaeological iron samples of known age, prepared and dated by these two methods, are presented and discussed.