Historical artefacts like moa bones can be dated using a technique that measures the activity of the radioisotope carbon-14 still present in the sample.
By comparing this with a modern standard, an estimate of the calendar age of the artefact can be made.
The C-14 atoms present in the benzene decay at a certain rate.
The carbon dioxide formed in the combustion stage is heated in the presence of pure lithium metal, which produces lithium carbide.
When all of the carbon dioxide has reacted, distilled water is added to the lithium carbide and a chemical reaction occurs, resulting in the production of acetylene gas.
The decay events for each sample are measured over a week.
The results from the liquid scintillation spectrometer are carefully analysed and provide a radiocarbon age for the sample.
This allows corrections to be made on radiocarbon dates in order to produce more accurate dates.