Quantitation from Tafel Analysis in Solid-State Voltammetry. Application to the Study of Cobalt and Copper Pigments in Severely Damaged Frescoes

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• 作者：Antonio Domé ; nech ; Mar&iacute ; a Teresa Domé ; nech-Carbó ; Howell G. M. Edwards
• 刊名：Analytical Chemistry
• 出版年：2008
• 出版时间：April 15, 2008
• 年：2008
• 卷：80
• 期：8
• 页码：2704 - 2716
• 全文大小：692K
• 年卷期：v.80,no.8(April 15, 2008)
• ISSN：1520-6882

文摘

A novel method, using Tafel plots, for quantifying electroactive species in solid materials when their voltammetric signals are strongly overlapped is described. This isapplied to the analysis of submicrosamples from thehighly damaged frescoes painted by Palomino (1707) inthe ceiling vault of the Sant Joan del Mercat church inValencia, Spain. These paintings, which were fired in1936, contained cobalt smalt plus azurite mixtures, thislast being altered to tenorite (CuO). The reported methodprovides a quantitation of the cobalt smalt/azurite, tenorite/(azurite + smalt) relationships in samples, thusproviding direct information on pigment dosage (smalt/azurite ratio) in pristine paintings, extent of alteration, andtemperature experienced by the frescoes during thegunfire episode. Distinction between Palomino paintingsand other painters was clearly obtained due to the presence of malachite in these last.