In this work, 960 réis coins from the period when Brazil was a colony of Portugal were analyzed using the x-ray fluorescence (XRF) spectrometry. The history of these coins, dated between the end of the 17th century and the beginning of the 19th century, had a great influence on the immigration of the Portuguese Prince Regent D. João to Brazil, who arrived in 1808. Bearing in mind the need to expand the timid Brazilian monetary system, the Portuguese crown decided to collect Spanish silver pesos of 8 reales, recoined with a value of 960 réis. The recoinage procedure was carried out using a stamp; therefore, in many cases, it is possible to check the base currency. In this work, were investigated 17 samples of 960 réis coins by XRF, in which the base coin was 8 reales manufactured with raw materials from Mexican mines. In addition to characterizing the elemental composition of the coins, the XRF data were evaluated using multivariate statistical method of Robust Principal Component Analysis (ROBPCA), which was used to classify the coins based on their elemental composition. However, with XRF, elementary information is obtained for a depth of only a few micrometers. One of the essential issues in Ag–Cu metal alloys is the Ag enrichment, which can cause changes to the elemental composition of the surface. Therefore, initially, a study was carried out to verify whether the surface compositions of the coins were altered by the Ag enrichment.

在这项工作中，使用X射线荧光（XRF）光谱仪分析了巴西是葡萄牙殖民地时期的960里斯硬币。这些硬币的历史可追溯到17世纪末至19世纪初，对葡萄牙摄政王D.João到1808年到达巴西的移民产生了重大影响。扩大胆小巴西货币体系，葡萄牙人冠决定收集8个的西班牙银元比索里亚尔，与960个的值recoined REIS。使用邮票进行重新兑换程序；因此，在许多情况下，可以检查基础货币。在这项工作中，调查了960里斯的17个样本XRF铸造的硬币，其中基础硬币为8里尔，使用墨西哥矿山的原材料制造。除了表征硬币的元素组成外，还使用稳健主成分分析（ROBPCA）的多元统计方法评估XRF数据，该方法用于根据硬币的元素组成对硬币进行分类。但是，使用XRF只能获得几微米深度的基本信息。Ag-Cu金属合金的基本问题之一是Ag的富集，这会引起表面元素组成的变化。因此，最初，进行了研究以验证硬币的表面组成是否因Ag富集而改变。