Abstract Lead white was a white pigment extensively used in paintings from Antiquity until the beginning of the 20th century. It is composed of hydrocerussite (Pb3(CO3)2(OH)2) and cerussite (PbCO3). Historical recipes report metallic lead, vinegar and horse manure as ingredients to produce the two lead carbonates. The incorporation of organic CO2 carrying 14C representative of the time of manufacture of lead white allows radiocarbon dating of this pigment. One possible protocol for lead white paint preparation for dating is based on the extraction of carbon from lead carbonates by thermal decomposition. Since lead white paints are mixed with a binder and other pigments, a thermogravimetric study was implemented to study CO2 extraction from each component. The measurements were carried out on samples of modern paints prepared with lead white (lead carbonate), Meudon white (calcium carbonate) and linseed oil. The results show that it is possible to separate the carbon of interest (carrying the 14C signature: lead white and linseed oil) from the dead carbon coming from geological carbonates (containing no radiocarbon: Meudon white) by heating the paint sample at 400 °C. This study provides a better understanding of the thermal behavior of these three paint constituents and confirms the validity of the thermal protocol for the preparation of lead white paints for radiocarbon dating.

中文翻译：

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碳酸盐颜料和亚麻籽油的热分析以优化 CO2 提取，用于铅白画的放射性碳测年

摘要 铅白是一种从古代到 20 世纪初广泛用于绘画的白色颜料。它由水蜡矿（Pb3（CO3）2（OH）2）和蜡矿（PbCO3）组成。历史配方报告称金属铅、醋和马粪是生产这两种碳酸铅的成分。含有代表铅白制造时间的 14C 有机 CO2 的掺入允许对该颜料进行放射性碳测年。用于测年的铅白涂料制备的一种可能协议是基于通过热分解从碳酸铅中提取碳。由于铅白涂料与粘合剂和其他颜料混合，因此进行了热重研究以研究从每个成分中提取的 CO2。测量是在用铅白（碳酸铅）、Meudon 白（碳酸钙）和亚麻籽油制备的现代涂料样品上进行的。结果表明，通过在 400 °C 下加热涂料样品，可以将感兴趣的碳（带有 14C 特征：铅白和亚麻籽油）与来自地质碳酸盐（不含放射性碳：默东白）的死碳分离. 这项研究提供了对这三种涂料成分的热行为的更好理解，并证实了用于制备用于放射性碳测年的铅白涂料的热协议的有效性。铅白和亚麻籽油）来自地质碳酸盐（不含放射性碳：默东白）的死碳，通过在 400 °C 下加热涂料样品。这项研究提供了对这三种涂料成分的热行为的更好理解，并证实了用于制备用于放射性碳测年的铅白涂料的热协议的有效性。铅白和亚麻籽油）来自地质碳酸盐（不含放射性碳：默东白）的死碳，通过在 400 °C 下加热涂料样品。这项研究提供了对这三种涂料成分的热行为的更好理解，并证实了用于制备用于放射性碳测年的铅白涂料的热协议的有效性。