人牙齿中锶的特效树脂分离及其同位素测定

采用锶特效树脂(Sr-Spec)建立了快速分离富集人牙齿中微量元素锶,并测定87Sr/86Sr的有效方法。采用HNO3-HClO4体系消解牙齿样品,以8mol/L HNO3为介质上柱,8mol/L HNO3淋洗,0.05mol/LHNO3洗脱,收集淋洗液,蒸干;采用正热电离质谱法进行87Sr/86Sr的测定。结果表明,利用Sr-Spec树脂,不仅能将锶与基质中大量钙分离,并能有效分离同位素测定中干扰元素铷。本方法可以缩短分离时间,提高分离效率,减少试剂用量,降低实验空白。采用本方法对陕南地区人牙齿牙釉质中锶进行分离,测得的87Sr/86Sr值在0.710948～0.711037之间。

Separation and Isotopic Measurement of Sr in Tooth Samples Using Selective Specific Resins

Strontium isotope of ancient human teeth provides an important scientific basis for ancient population migration,and Palaeodietary analysis.A fast and effective method for separation,preconcentration and isotopic determination of strontium with low content and rich calcium of tooth samples by Sr-Spec selective specific resin was established.The samples were completed dissolved with mixed acid of HNO3-HClO4.Sr was increasingly well retained by Sr resin for mobile phases with nitric acid concentrations of 8 mol/L,However,potential interferences,like Ca,Rb will elute within the 8 mol/L nitric acid.Once adsorped,Sr can be eluted from the column by changing the mobile phase to weak nitric acid of 0.05 mol/L.In comparison with the conventional separation procedures,the method has the advantages of fewer steps of separation,less usage of elution solutions and lower reagent blanks.The proposed method was used for the determination of 10 none carious teeth of enamel collected in southern of shaanxi.Giving values of 87Sr/86Sr were in the range of 0.710948～0.711037.