Finnigan flash ea

For collagen extraction, both human and faunal tooth dentine and bone samples, weighing between ~200 and 500 mg, were carefully removed using a diamond-tipped burr. Collagen was extracted following the protocol described in Talamo and Richards^{85 (link)}. Dentine and bone were cleaned by abrasion and then demineralized in HCl for several weeks at 4 °C. The samples were immersed in NaOH for 30 minutes. The purified solution containing collagen was rinsed and soaked again in HCl. The insoluble collagen was solubilized in HCl (pH 3) at 75 °C for 20 h. The supernatant containing the collagen was filtered with Ezee filters and then ultra-filtrated to collect the >30 kDa collagen molecules, frozen for 48 h and lyophilized.
The C and N isotopic ratios were obtained using a Thermo Finnigan Flash EA coupled to a Delta V isotope ratio mass spectrometer. Carbon and nitrogen stable isotope ratios were measured relative to Vienna PeeDee Belemnite and atmospheric N₂, respectively. The analytical errors of 0.1‰ and 0.2‰ for δ¹³C and δ¹⁵N were determined by the repeated analysis of internal and international standards (IAEA-N1, IAEA-N2, MET and MRG).

Stable isotopes of collagen from Tagliente 2 (from the root of the lower left first molar) were measured using a Thermo Finnigan Flash EA coupled to a Delta V isotope ratio mass spectrometer at the Max Planck Institute for Evolutionary Anthropology, Leipzig (MPI‐EVA) (see Supporting information and Table 3).
Mondeval bone samples (Table 3) for stable isotope analysis were treated for collagen extraction at the Laboratoire de Biochimie de l'Unité d'Anthropologie de Marseille (France), following protocols previously published (Bocherens et al., 1997; Longin, 1971; see Supporting information). Collagen was then analyzed for stable isotopes at the Iso‐Analytical lab (Sandbach, UK.; Gazzoni, 2011).