Project summary

The main aim of the artMAP project is to develop a new analytical methodology for in-situ identification and real-time mapping of organic binders used in ancient wall paintings. The proposed method combines two complementary highly specific molecular techniques, namely Laser-induced fluorescence (LIF) and Fourier-transform infrared (FTIR) spectroscopy. The existing LIF scanning system within the INOE 2000 laboratory will be upgraded with a new laser source and a new software interface will be developed along with a spectral database of organic compounds. The capability to accurately identify and map organic binders in ancient wall paintings, typically characterized by a highly inorganic matrix and low binder-to-pigment ratio, will be tested on selected 2^nd century Roman wall painting fragments. A two-step optimization method will be used (two level of identification): (1) LIF measurements will be carried as a first step for remote non-invasive real-time diagnosis and mapping of the organic components that may be present within the investigated samples; this will offer a first level of identification, meaning the presence or absence of an organic binder, and at the same will indicate (based on the imaging results) the best points on the painted surface at which to take micro-samples; (2) results of the LIF analysis will be refined and validated by FTIR measurements carried out on selected micro-samples that will be subject to a pretreatment (selective extraction method of the organic binder using solvents); this will offer a second level of identification, meaning identification of specific classes of organic binding media. This combined procedure will give a synergic effect as the chemical identification of the organic materials provided by FTIR spectroscopy can be transferred to the whole painted surface thanks to the imaging capabilities of the LIF system, without the need for extensive micro-sampling.