@article{oai:nagoya.repo.nii.ac.jp:00011864, author = {瀧上, 舞 and TAKIGAMI, Mai and 南, 雅代 and MINAMI, Masayo and 中村, 俊夫 and NAKAMURA, Toshio}, journal = {名古屋大学加速器質量分析計業績報告書}, month = {Mar}, note = {Prehistrical human bone is used for ^<14>C dating and isotope palaeodietary analysis. Fossil bone tends to be suffered from exogenous contaminants and diagenetic alteration during burial, especially in tropical and wet areas, and the state of bone collagen preservation differs with each bone sample. Since bone sections in an individual have different internal structures, such as density, thickness, amount of spongins and compact bone, different sections could have various levels of diagenesis. In this study, we investigated whether collagen extracted from different sections of an individual has variations of C/N ratios, δ^<13>C and δ^<15>N values for different sections of an individual, and whether we can estimate its palaeodietary by analyzing one bone section of a whole individual. The samples used are eleven bone sections (cranium, sphenoid, tooth, rib, humerus, radius or ulna, the lower femur, the central femur, tibia and two back-bones) in an individual, nine sections in another, and seven sections in the other, collected from the Yuigahama-minami archealogical site, Kamakura, Japan. The surface of fossil samples were shaved and ultrasonicated repeatedly in distilled water, followed by HCl and NaOH treatments; then samples were lyophilized and pulverized. The powdered bone sample was treated with 0.6M-HCl in a cellulose tube in a beaker over 20h at 4℃. The decalcified bone sample was treated by 0.6M-NaOH followed by 1.2M-HCl and 0.6M-HCl. Gelatin was extracted from acid/alkali-insoluble residue by heating in distilled water for 12h at 80-90℃. Combusted gelatin was refined into N_2 and CO_2. These gases were used for carbon and nitrogen isotopic measurement by using an isotope ratio mass spectrometer (Finnigan, MAT252). Gelatin was wrapped into a Sn cup and measured for C/N ratios by using an elemental analyzer (Euro Vector, Euro EA3000). To estimate sample preparation-induced variation, seven gelatins were extracted from a bone section, and each measured for C/N ratios, δ^<13>C and δ^<15>N values. The deviations of δ^<13>C and δ^<15>N values for seven gelatins are ±0.1‰ and ±0.2‰, respectively. Most bone sections have gelatin yield of more than 0.7 wt%, and carbon yield of the combusted gelatin between 42 and 46 wt%. Bone with more than 0.7 wt% gelatin is generally well preserved, and collagens with around 40 wt% C are intact. The bone samples in this study, therefore, are well preserved and regarded as suitable for analysis. The C/N ratios of gelatins varied from 3.1 to 3.4 with different sections in an individual. The values show quality of the gelatin extractions because the good collagens have C/N ratios between 2.9 and 3.6. The δ^<13>C values of gelatins have variations of about 1‰, between -19.3 and -18.2‰, for different bone sections in an individual. The other two individuals have variations between -19.3 and -18.4‰, and -18.3 and -17.7‰. The δ^<15>N values have variations of about 1.5‰ (12.6〜14.0‰, 12.4〜13.1‰ and 12.6〜14.1‰, respectively) for different sections of each individual. There is a positive correlation between δ^<13>C and δ^<15>N values. The back-bones tend to have highest values, and the rib and tooth have a little higher values than the others. ^<14>C ages have no variation in different sections. It means exterior organic substance don't get mixed in gelatin., 第20回名古屋大学年代測定総合研究センターシンポジウム平成19(2007)年度報告<第2部> Proceedings of the 20th symposiumon on Chronological Studies at the Nagoya University Center for Chronological Research in 2007 日時:平成20 (2008)年1月10日(木)~11日(金) 会場:名古屋大学野依記念学術交流館 Date:January10th-11th, 2008 Venue:Nagoya Uhiversity Noyori Conference Hall}, pages = {117--126}, title = {古人骨の同一個体内における部位の違いによるC/N比、 δ^<13>C値、δ^<15>N値、^<14>C年代の相違(第20回名古屋大学年代測定総合研究センターシンポジウム平成19(2007)年度報告)}, volume = {19}, year = {2008} }