In this paper we report the results of a deep investigation of gold title in jewellery alloys by means of potentiometric titration. After reviewing the suitable reactions for such purpose we focused on the most profitable one, which involves the use of hexadecylpyridinium chloride (CPC). This cation gives rise to selective and quantitative precipitation of AuCl4−. We completely revised a method previously proposed by W.S. Selig in the 80’s, by improving the sampling preparation and by optimizing the titration steps. Then, the new proposed method was tested on a large number of different alloys, commonly used for goldsmithery purposes. The obtained gold titles were compared with the data achieved by fire assay, giving rise to a very good agreement. At the light of these results, the present method can be rightfully considered a cheaper and “greener” alternative to the traditional one.

中文翻译：

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电位滴定法测定合金中的金；火测定的替代方法

在本文中，我们报告了通过电位滴定法深入研究珠宝合金中的金标题的结果。在审查了用于此目的的合适反应后，我们专注于最有利可图的反应，其中涉及使用十六烷基氯化吡啶 (CPC)。这种阳离子引起 AuCl4- 的选择性和定量沉淀。我们通过改进采样准备和优化滴定步骤，彻底修改了 WS Selig 在 80 年代之前提出的方法。然后，新提出的方法在大量不同的合金上进行了测试，这些合金通常用于金匠目的。将获得的金标题与通过火分析获得的数据进行比较，产生了非常好的一致性。鉴于这些结果，