title: Fourier Transform Raman and Statistical Analysis of Thermally Altered Samples of Amber.
abstract: We report the experimental results that refer to a Fourier transform Raman (FT-Raman) survey of thermally altered Baltic and Romanian amber and the related statistical interpretation of data using principal component analysis (PCA). Although FT-Raman spectra show several small changes in the characteristic features of the investigated amber samples which may be used for discrimination, their visual recognition is relatively difficult, especially when interpreting data from archeological samples, and thus multivariate data analysis may be the solution to more accurately assign the geological origin based on overall characteristic spectral features. The two categories of amber have different behavior in terms of degradation during the experimental alteration, and Romanian amber is more susceptible to physico-chemical transformations by the aggressive environment when compared with Baltic amber. The obtained data were in accordance with the Fourier transform infrared (FT-IR) remarks published previously in a dedicated journal. The Raman technique is an alternative method that requires little to no sample preparation, water does not cause interference, and the spectra can be collected from a small volume (1-50 μm in diameter).
authors.affiliation: National Institute for Biological Sciences, Centre of Bioanalysis, 296 Splaiul Independentei, 060031, Bucharest, Romania.
authors.forename: Georgiana I
authors.initials: GI
authors.lastname: Badea
authors.forename: Maria C
authors.initials: MC
authors.lastname: Caggiani
authors.forename: Philippe
authors.initials: P
authors.lastname: Colomban
authors.forename: Annarosa
authors.initials: A
authors.lastname: Mangone
authors.forename: Eugenia D
authors.initials: ED
authors.lastname: Teodor
authors.forename: Eugen S
authors.initials: ES
authors.lastname: Teodor
authors.forename: Gabriel L
authors.initials: GL
authors.lastname: Radu
mesh_terms: D018647:Amber / Q000737:chemistry*; D025341:Principal Component Analysis; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D018647:Amber