Effects of consolidants and their removal by polar solvents on the stable isotope compositions of bone

Although conservation practices facilitate the preservation of museum collections, procedures used to stabilize ancient materials can alter their chemical and isotopic compositions, impacting the viability of such specimens for life history investigations. In this study, we applied two common consolidants – polyvinyl acetate (PVAc) and acrylic resin (Paraloid B-72™) – followed by two consolidant removal procedures to assess the impacts of these processes on the stable isotope compositions and structural characteristics of a series of subsamples taken from a representative archaeological faunal bone. We examined the collagen (δ13Ccol and δ15Ncol), structural carbonate (δ13Csc and δ18Osc), and phosphate (δ18Op) isotopic compositions of the bone sample before and after consolidation to evaluate consolidant removal procedures. We also measured δ13Csc, δ18Osc, and structural characteristics before and after the pre-treatment commonly used to remove organic matter and secondary carbonate prior to isotopic analyses.