DO WEAK OR STRONG ACIDS REMOVE CARBONATE CONTAMINATION FROM ANCIENT TOOTH ENAMEL MORE EFFECTIVELY? THE EFFECT OF ACID PRETREATMENT ON RADIOCARBON AND δ13C ANALYSES
| Autor: | Mai Huong Nguyen Thi, Anh Tuan Nguyen, Andre Barros Curado Fleury, Stewart Fallon, Rachel Wood |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010506 paleontology
Archeology 060102 archaeology δ13C Strong acids 06 humanities and the arts Tooth enamel 01 natural sciences Archaeology law.invention chemistry.chemical_compound medicine.anatomical_structure chemistry law Research council medicine General Earth and Planetary Sciences Carbonate 0601 history and archaeology Radiocarbon dating Geology 0105 earth and related environmental sciences |
| Zdroj: | Radiocarbon. 63:935-952 |
| ISSN: | 1945-5755 0033-8222 |
| DOI: | 10.1017/rdc.2021.32 |
| Popis: | In hot environments, collagen, which is normally targeted when radiocarbon (14C) dating bone, rapidly degrades. With little other skeletal material suitable for 14C dating, it can be impossible to obtain dates directly on skeletal materials. A small amount of carbonate occurs in hydroxyapatite, the mineral phase of bone and tooth enamel, and has been used as an alternative to collagen. Unfortunately, the mineral phase is often heavily contaminated with exogenous carbonate causing 14C dates to underestimate the true age of a sample. Although tooth enamel, with its larger, more stable crystals and lower porosity, is likely to be more robust to diagenesis than bone, little work has been undertaken to investigate how exogenous carbonate can be effectively removed prior to 14C dating. Typically, acid is used to dissolve calcite and etch the surface of the enamel, but it is unclear which acid is most effective. This study repeats and extends earlier work using a wider range of samples and acids and chelating agents (hydrochloric, lactic, acetic and propionic acids, and EDTA). We find that weaker acids remove carbonate contaminants more effectively than stronger acids, and acetic acid is the most effective. However, accurate dates cannot always be obtained. |
| Databáze: | OpenAIRE |
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