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.

中文翻译：

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弱酸或强酸能更有效地去除古牙釉质中的碳酸盐污染吗？酸预处理对放射性碳和 δ13C 分析的影响

在炎热的环境中，胶原蛋白通常是放射性碳（14C) 约会骨头，迅速退化。几乎没有其他适合的骨骼材料14C 测年，可能无法直接在骨骼材料上获得日期。少量碳酸盐存在于羟基磷灰石（骨骼和牙釉质的矿物相）中，已被用作胶原蛋白的替代品。不幸的是，矿物相经常受到外源碳酸盐的严重污染，导致14C 日期低估了样本的真实年龄。尽管牙釉质具有更大、更稳定的晶体和更低的孔隙率，可能比骨骼更能抵抗成岩作用，但很少有工作来研究如何在牙釉质之前有效去除外源性碳酸盐。14C约会。通常，酸用于溶解方解石并蚀刻牙釉质表面，但尚不清楚哪种酸最有效。本研究使用更广泛的样品、酸和螯合剂（盐酸、乳酸、乙酸和丙酸以及 EDTA）重复并扩展了早期的工作。我们发现较弱的酸比强酸更有效地去除碳酸盐污染物，而乙酸是最有效的。但是，不能总是获得准确的日期。