title: ATR-FTIR spectroscopy as a way to identify natural protein-based materials, tortoiseshell and horn, from their protein-based imitation, galalith.
abstract: This paper presents a new totally non-destructive methodology, for the identification of protein-based materials, tortoiseshell, horn and galalith, on heritage objects. Attenuated total reflexion (ATR) infrared spectroscopy combined to a deconvolution procedure of amide I band was performed to characterize the secondary structure of these materials and allows us to identify each material. The component at 1639 cm(-1), attributed to the amide group involved in hydrated random-coil domains, allows us to distinguish horn from galalith and tortoiseshell. A second component, at 1614 cm(-1), assigned to amide group involved in protein self-association, allows us to differentiate galalith and tortoiseshell. This differentiation is applicable to both raw and manufactured materials. Then, we applied our models to identify what unknown object was made of.
authors.affiliation: Laboratoire de Dynamique, Interaction et Réactivité, CNRS/UPMC 2 rue Henri Dunant, F-94320 Thiais, France. celine.paris@glvt-cnrs.fr
authors.forename: Céline
authors.initials: C
authors.lastname: Paris
authors.forename: Sophie
authors.initials: S
authors.lastname: Lecomte
authors.forename: Claude
authors.initials: C
authors.lastname: Coupry
mesh_terms: D000825:Animal Structures / Q000033:anatomy & histology / Q000737:chemistry*; D000818:Animals; D002364:Caseins / Q000737:chemistry* / Q000302:isolation & purification; D006733:Horns / Q000033:anatomy & histology / Q000737:chemistry*; D006860:Hydrogen Bonding; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D014426:Turtles
chemical_list: D002364:Caseins; D011506:Proteins