热电离质谱法测定龋齿牙釉质^87Sr／^86Sr同位素比值

Isotopic Measurement of Sr in Carious Teeth of Enamel by Thermal Ionization Mass Spectrometry

锶同位素已经成为国际考古学界用于探索人和动物迁移活动和食谱组成的主要方法。本文利用锶特效树脂(Sr-Spec),建立了快速分离富集于人龋齿中的微量元素锶,并测定87Sr/86Sr的有效方法。采用硝酸-高氯酸体系消解龋齿样品,利用锶特效树脂(Sr-Spec)快速分离富集龋齿中微量元素锶(Sr),最后采用IsoProbe-T固体热电离质谱计测定龋齿87Sr/86Sr同位素比值。实验结果表明,不同年龄和性别龋齿牙釉质的87Sr/86Sr同位素比值在0.710935～0.711034之间较小区间范围,基本趋于稳定,说明生活在相同地质背景的人或动物,其机体内Sr同位素比值接近。男性龋齿牙釉质87Sr/86Sr比值随着年龄的增长有微小的波动,从0.710935升高到0.711031,这些微小变化可能与样本人群的环境和生活习惯相关。

Strontium isotope of ancient human teeth provides an important scientific basis for the study of ancient population migration and palaeodietary. A fast and effective method for separation, preconcentration and isotopic determination of low-content strontium of Ca-rich tooth samples by Sr-Spec selective specific resin was established. The carious teeth of enamel were completely dissolved with HNOa-HC1O4 mixed acid. The Sr in carious teeth of enamel was separated by Sr-Spec selective specific resin, and the Sr isotope was analyzed by thermal ionization mass spectrometry. The results show that the ^87Sr/^86Sr ratios vary in the small range of 0.710935-0.711034, and that the isotope of Sr was similar when people lived in the same geological background. The ^87Sr/^86Sr ratios of male teeth have slight fluctuations, from 0.710935 to 0.711031, which may be attributed to living environments and eating habits.