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DTSTART;VALUE=DATE:20241114T110000
DTEND;VALUE=DATE:20241114T120000
UID:16303@agenda.unifr.ch
DESCRIPTION:Any observer of an artwork speculates about two details: who is the artist, and when was the object created. Answering these queries is not an easy task, however the second question may be addressed by radiocarbon (14C) dating. Such information, however, can only be obtained by sacrificing a sample from the object, a critical step owing to the unique and irreplaceable nature of art objects. Organic compounds isolated from natural sources are potential chronological markers for the object’s life. Omnipresent in cultural heritage objects, organic colorants are found in a wide range of substrates from different cultures, displaying different artistic techniques and preservation states, covering different time periods from 5000 BCE till today. Carbon-rich and short-lived, the carbon isotopic ratio of organic colorants represents a snapshot of the atmospheric CO2 during the years of growth of the organism (plant or insect) from which it was isolated. As such, these compounds represent ideal material for 14C analysis and can serve as proxies for dating the creation of a colored object, yet until today, no such analysis has ever been conducted. With the focus on red anthraquinone dyes used in historical dyed textiles, preliminary results in developing a new protocol combining dye analysis by ultra-high-performance liquid chromatography (HPLC) and compound-specific radiocarbon analysis (CSRA) will be presented. 
SUMMARY:The when of colour: tailored radiocarbon analysis of natural organic dyes and pigments in heritage science 
CATEGORIES:Séminaire
LOCATION:PER 18\, Auditorium\, Chemin des Verdiers 4\, 1700 Fribourg
URL;VALUE=URI:https://agenda.unifr.ch/e/fr/16303
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