title: Multispectroscopic and Isotopic Ratio Analysis To Characterize the Inorganic Binder Used on Pompeian Pink and Purple Lake Pigments.
abstract: Because of the fact that pigments are not ubiquitous in the archeological record, the application of noninvasive analytical methods is a necessity. In this work, pink and purple lake pigments recovered from the excavations of the ancient city of Pompeii (Campania, Italy) and preserved in their original bowls at the Naples National Archaeological Museum (Italy) were analyzed to characterize the composition of their inorganic binders (mordants). In situ preliminary analyses using a hand-held energy dispersive X-ray fluorescence spectrometer (HH-ED-XRF) allowed us to determine the use of an aluminosilicate enriched in Cu and Pb. Scanning electron microscopy coupled to energy dispersive X-ray spectrometry (SEM-EDS) and benchtop ED-XRF analyses confirmed these results, while inductively coupled plasma mass spectrometry (ICPMS) allowed one to determine the concentration of major, minor, and trace elements. The use of other techniques such as X-ray diffraction (XRD), and micro-Raman and infrared spectroscopies allowed one to characterize the pigments at the molecular level. The high concentration of Cu detected in the pigments (1228-12937 μg g(-1)) could be related to the addition of Cu salts to obtain the desired final hue. The concentrations of Pb (987-2083 μg g(-1)) was also remarkable. Lead isotopic ratio analysis ((206)Pb/(207)Pb) suggested a possible origin related to the leaching of the ancient lead pipes from Pompeii and the subsequent transfer to the buried pigments or to the inorganic binder. Molecular analysis also showed that the binder is composed of an allophane-like clay. Moreover, it was possible to determine that to obtain the final purple hue of a specific pigment, Pompeian blue pigment was also mixed into the dyed clay.
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU , P.O. Box 644, 48080 Bilbao, Basque Country, Spain.
authors.forename: Iker
authors.initials: I
authors.lastname: Marcaida
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country UPV/EHU , P.O. Box 450, 01080 Vitoria-Gasteiz, Basque Country, Spain.
authors.forename: Maite
authors.initials: M
authors.lastname: Maguregui
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU , P.O. Box 644, 48080 Bilbao, Basque Country, Spain.
authors.forename: Héctor
authors.initials: H
authors.lastname: Morillas
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU , P.O. Box 644, 48080 Bilbao, Basque Country, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: García-Florentino
authors.affiliation: University of Helsinki , Faculty of Science, Department of Chemistry, P.O. Box 44, Helsinki, FI-00014, Finland.|Jyväskylä University , Faculty of Humanities, Department of Art and Culture Studies/Museology, P.O. Box 35, FIN-40014 Jyväskylä, Finland.
authors.forename: Ulla
authors.initials: U
authors.lastname: Knuutinen
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU , P.O. Box 644, 48080 Bilbao, Basque Country, Spain.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Carrero
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU , P.O. Box 644, 48080 Bilbao, Basque Country, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Fdez-Ortiz de Vallejuelo
authors.affiliation: UMR-CNRS 5199 PACEA, Préhistoire, Paléoenvironnement, Patrimoine, Université de Bordeaux , Bâtiment B18, Allée Geoffroy St. Hilaire, 33615 Pessac, France.|Grup de Recerca Aplicada al Patrimoni Cultural (GRAPAC), Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia, Facultat de Biociènces, Univeritat Autònoma de Barcelona , Campus Bellaterra, 08193 Bellaterra, Spain.
authors.forename: Africa
authors.initials: A
authors.lastname: Pitarch Martı́
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU , P.O. Box 644, 48080 Bilbao, Basque Country, Spain.
authors.forename: Kepa
authors.initials: K
authors.lastname: Castro
authors.affiliation: Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country UPV/EHU , P.O. Box 644, 48080 Bilbao, Basque Country, Spain.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Madariaga