1. Dept of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy
2. Museum Conservation Institute, Smithsonian Institution, 4210 Silver Hill Rd, Suitland 20746, Maryland, United States
3. Dept of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy