The Issue of Contamination by Synthetic Resins in Radiocarbon Dating: The Case of a Painting by Ambrogio Lorenzetti

Nowadays, the most common products used in restoration are of synthetic origin. Being these resins obtained from fossil oil, they are devoid of 14C. Therefore, a not complete removal from the sample to be dated can be the cause of a consistent apparent ageing of the dated artworks. A chemical pre-treatment is required in order to clean the samples before the measurements. At INFN-LABEC laboratory in Florence, a new procedure based on the use of an extraction with chloroform as solvent was tested. In this paper, the radiocarbon measurements made on a restored polyptyc by Ambrogio Lorenzetti are presented.