發(fā)布時間：2019-05-10 02:02

【摘要】：Mg是構(gòu)成牙齒重要組分,其含量和同位素組成可記錄居民生活地域、飲食習(xí)慣以及口腔健康信息等重要信息。本研究建立了高精度多接收等離子質(zhì)譜(MC-ICP-MS)測定牙齒中Mg同位素方法。牙齒樣品經(jīng)微波消解儀消解,后采用AG50W-X8陽離子樹脂分離溶液中的Mg元素,以1 mol/L HNO_3為介質(zhì)上柱,40 m L1 mol/L HNO_3洗脫Na~+等雜質(zhì)離子,再以30 m L 1 mol/L HNO_3收集Mg元素,60 m L 1 mol/L HNO_3洗去其它雜質(zhì),蒸干Mg收集液。MC-ICP-MS進(jìn)行Mg同位素組成測定。MC-ICP-MS儀器自身的質(zhì)量分餾利用"樣品-標(biāo)準(zhǔn)"交叉技術(shù)("Sample-standard"bracketing technique)解決。實驗結(jié)果表明,利用AG50W-X8陽離子樹脂,可在保證Mg回收率的情況下,將牙齒樣品中的Mg和其它基質(zhì)元素徹底分離,且不造成同位素分餾。采用此方法對現(xiàn)代人離體牙牙釉質(zhì)中Mg同位素進(jìn)行分離測定,牙齒的δ~(26)Mg在較大的范圍變化(!1.38‰~4.59‰)。本方法為利用人牙齒中Mg同位素研究Mg的暴露水平、環(huán)境污染等信息提供重要的實驗和理論依據(jù)。
[Abstract]:Mg is an important component of teeth. Its content and isotopic composition can record important information such as living area, eating habits and oral health information. In this study, a high precision multi-receiver plasma mass spectrometry (MC-ICP-MS) method for the determination of Mg isotopes in teeth was established. The tooth samples were digested by microwave digestion instrument, and then the Mg elements in the solution were separated by AG50W-X8 cationic resin. The impurity ions such as Na~ were eluted by 40 ml mol/L HNO_3 on a column with 1 mol/L HNO_3 as medium. Then Mg elements were collected with 30 mL 1 mol/L HNO_3, and other impurities were washed away by 60 mL 1 mol/L HNO_3. Evaporated Mg collection solution. MC-ICP-MS is used for the determination of Mg isotopic composition. The mass fractionation of MC-ICP-MS instrument itself is solved by "sample-standard" cross technique ("Sample-standard" bracketing technique). The experimental results show that AG50W-X8 cationic resin can completely separate Mg from other matrix elements without isotopic fractionation under the condition of ensuring the recovery of Mg. This method was used to separate and determine the Mg isotope in the enamel of modern human teeth. The 未 ~ (26) Mg of the teeth varied in a wide range (! 1.38 鈥，

本文編號：2473262