Well-preserved human or animal teeth samples can yield valuable insights through the application of AMS radiocarbon dating. It is recommended to provide an intact tooth sample to ensure a successful AMS C14 analysis. Before the radiocarbon (14C) dating process begins, all samples are carefully chosen and prepared based on factors such as the material's type, quantity, and condition. Subsequently, these samples undergo graphitization, a critical step in the carbon dating procedure that demands a high level of expertise to achieve dependable and precise results. At the VILNIUS RADIOCARBON laboratory, we employ top-of-the-line chemicals and consumables available in the market for the pre-treatment of samples. Our procedures strictly adhere to internally approved methodologies outlined in the provided protocols. In addition to providing C14 results, we also furnish information on the quantities of carbon (C), nitrogen (N), C/N atomic ratio, and yield. Upon request, we can further measure d13C and d15N stable isotope values using the Isoprime VISION isotope ratio mass spectrometer from Elementar GmbH (Germany) to provide comprehensive insights into background of the samples.
Preferred sample size: 1-2 teeth
Minimum sample size: 1 tooth
Regarding AMS radiocarbon dating of teeth, two material sources are available and can be dated: tooth dentine and enamel.
The preparation of tooth dentine samples involves standard acid-base-acid (ABA) procedure and collagen extraction. Firstly, bone samples are ultrasonicated in ultrapure water, dried, grinded and sieved to get the appropriately sized sample fraction (0.5–1 mm). Then samples are treated with 0.5M hydrochloric acid (~18 hr), 0.1-0.2M sodium hydroxide (30 min-1h), and 0.5M hydrochloric acid (1 hr). Bone collagen gelatinization is performed in pH 3 solution at 70°C for 20 hr. Gelatine solution is filtered using a cleaned Ezee-filter and freeze-dried. The quality of collagen is a critical factor in radiocarbon dating. It is monitored by carbon and nitrogen content in collagen, atomic C/N ratio determination and collagen yield. Samples are dated if the collagen yield is above 1% and the C:N ratio of the collagen is between 2.9 and 3.5. The samples that deviate from these ratios are deemed unsuitable for dating.
In cases where the tooth root is not preserved, the tooth enamel sample becomes eligible for dating. The preparation procedure for such a sample differs from the methodology used to isolate bone collagen. Enamel, being the mineral part of the tooth, is processed as a carbonate sample. Tooth enamel samples are prepared for radiocarbon dating as following. Samples are cleaned of the matrix, and enamel is separated from dentine using a hand-held Dremel drill. At least 6 mg tooth enamel powder is collected and pretreated with 30% hydrogen peroxide and acetic acid (buffered 1:1 with calcium acetate).
Before sending the sample, we recommend to check here, how your sample’s result in the dating certificate will look.