Leibniz laboratory for radiometric dating
Approximate sample sizes required for the AMS Please contact us before sending these samples.
* Sample size of dry peat; more material is required if the mineral content is high or the peat is decomposed. The precision of radiocarbon dates for recent samples (younger than 2000 years) of “normal” sample size (1-2 mg of carbon) is better than 0.5% (typically 0.3 - 0.4%) which equals /-40 years (25 - 30 years) for the 1-σ statistical uncertainty of the measured age.
Most commonly the AAA (acid-alkali-acid) method is used for organic samples like charcoal or organic remains.
Shells are cleaned and the outer part is dissolved in a weak acid.
charcoal, seeds, leaves, wood, and sediments), carbonates, and bones can be dated.
Prepared graphite targets are sent to an AMS laboratory for the measurement (at present to Pozna Radiocarbon Laboratory, Poland or to Leibniz Laboratory for Radiometric Dating and Isotope Research in Kiel, Germany).
Each batch of samples is accompanied by at least two modern standard (Oxalic Acid) and two background (coal or marble containing no radioactive carbon) samples, prepared in the same way as samples of unknown age which are used for the age calculation.
The progress of the reaction is monitored by measuring the pressure.
The reaction is usually complete after 3 to 4 hours.Low energy AMS spectrometer (called Tandy) at ETH Zurich, Switzerland or their 6MV machine.