@article{oai:nagoya.repo.nii.ac.jp:00011793,
 author = {中村, 俊夫 and Nakamura, Toshio and 太田, 友子 and Ohta, Tomoko and 西田, 真砂美 and Nishida, Masami},
 journal = {名古屋大学加速器質量分析計業績報告書},
 month = {Mar},
 note = {Ornaments made from Mammoth tusk were sold at a souvenir shop of the 2005 World Exposition at Nagakute, Aichi prefecture, Japan. One of the ornaments was ^<14>C dated to know the age of the Mammoth tusk by which the ornament was made from. The preparation of the sample for ^<14>C dating was done simply. The sample was cleaned with acetone on its surface, and part of the sample was scraped off from the sample surface with a dental drill. About 12 mg of the sample powder was combusted to CO_2 and finally converted to graphite, whose carbon isotopic ratios (^<14>C/^<12>C and ^<13>C/^<12>C) were measured with an accelerator mass spectrometry (AMS) system at Nagoya University. From the measured carbon isotope ratios, ^<14>C ages of the samples were calculated as 31,700±150 BP, with one-sigma errors. The obtained age was within the range of the ages measured so far for the mammoth samples collected from Siberian Far East in Russia. We cannot conclude definitely by the available data at present, but it is most possibly that the ornament is made from Mammoth tusk., タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 2005 (平成17)年度},
 pages = {172--176},
 title = {マンモスの牙材から作成された装飾品の^<14>C 年代測定(タンデトロン加速器質量分析計業績報告2005(平成17)年度)},
 volume = {17},
 year = {2006}
}