Comparative Decalcification Methods, Radiocarbon Dates, and Stable Isotopes of the VIRI Bones

Abstract

ABSTRACT. The Fifth International Radiocarbon Comparison (VIRI) provided a suite of 5 bone samples with consensus ages ranging from 969 to 39,305 14 C yr BP (Scott et al. 2010). These bones were used herein in a comparison of decalcification methods using either HCl or EDTA to produce collagen, and the results demonstrate age concordance between both preparation methods and the VIRI consensus values. Additional isotopic analyses of the collagen (ô l3 C, δ 15 Ν, and δ 18 0) illustrate the increasing sensitivity of carbon, nitrogen, and oxygen isotopes in assessing gelatin degradation.

Hydrogen isotopic analysis with a chromium-packed reactor of organic compounds of relevance to ecological, archaeological, and forensic applications

“…The collagen samples include a sub‐fossil bison long bone from Irish Gulch, Yukon, aged 41,200 ± 830 yr BP (uncal., OS‐124250, NOSAMS Facility, Woods Hole, MA, USA). It yielded morphologically well‐preserved collagen after EDTA demineralization . The modern collagens are a modern cow bone which was lipid extracted three times with 3:1 chloroform/methanol and demineralized with EDTA, and a rat tail tendon which was dissected, washed with cold saline solution three times, washed with deionized water once, and freeze‐dried.…”

The interconversion of δ2H values of collagen between thermal conversion reactor configurations

“…Bone fragments were demineralized in 0.5 M EDTA, rinsed multiple times in deionized water, freeze dried, and weighed into silver capsules …”

“…Bone fragments were demineralized in 0.5 M EDTA, rinsed multiple times in deionized water, freeze dried, and weighed into silver capsules. 11 Mass spectrometry conditions and reactor packing were as described previously. 6,9 We used a High-Temperature Conversion Elemental Analyzer (TC/EA, also sometimes abbreviated HTC) coupled via a Conflo III interface to a Delta Plus XP isotope ratio mass spectrometer (all from ThermoFinnigan, Bremen, Germany).…”

The Dutch whalers: a test of a human migration in the oxygen, carbon and nitrogen isotopes of cortical bone collagen

“…The collagen micro-samples were then placed in EDTA for two days to ensure complete removal of the mineral and rinsed in distilled water twelve times, including one overnight soak, to remove residual EDTA solution. Samples were not subjected to gelatinization, a technique that involves partial hydrolysis of the protein for two reasons: 1) identical carbon and nitrogen isotopic values from the same individual are generally obtained from both gelatinized and nongelatizined samples from well-preserved collagen (Tuross 2012;Tuross, Fogel and Hare 1988) Figure 2 Image of an unstained demineralized mid-shaft femur cross-section from whaler sample 2 (X 20 magnification; a 1mm scale bar shown in lower left). The black circle denotes where a punch was taken from an osteonal region.…”