Up to 70 % of the oil paintings conserved in collections present metal soaps, which result from the chemical reaction between metal ions present in the painted layers and free fatty acids from the lipidic binders. In recent decades, conservators and conservation scientists have been systematically identifying various and frequent conservation problems that can be linked to the formation of metal soaps. It is also increasingly recognized that metal soap formation may not compromise the integrity of paint so there is a need for careful assessment of the implications of metal soaps for conservation. This review aims to critically assess scientific literature related to commonly adopted analytical techniques for the analysis of metal soaps in oil paintings. A comparison of different analytical methods is provided, highlighting advantages associated with each, as well as limitations identified through the analysis of reference materials and applications to the analysis of samples from historical paintings.

中文翻译：

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油画中金属皂分析评述

收藏中保存的油画中高达 70% 含有金属皂，这是由画层中存在的金属离子与脂质粘合剂中的游离脂肪酸之间的化学反应产生的。近几十年来，保护者和保护科学家一直在系统地识别与金属皂的形成有关的各种常见的保护问题。人们也越来越认识到金属皂的形成可能不会损害油漆的完整性，因此需要仔细评估金属皂对保护的影响。本综述旨在批判性地评估与油画中金属皂分析常用分析技术相关的科学文献。提供了不同分析方法的比较，强调了每种方法的优点，以及通过分析参考材料和应用历史绘画样本分析发现的局限性。