5:15 PM - 6:30 PM
[HTT21-P09] Chemical separation of environmental materials for Stable Isotope Analysis
Keywords:Stable isotope, MC-ICP-MS, chemical separation, Sr resin
The purpose of this study is to describe a newly developed sequential separation of Sr, Pb, and Nd with Sr resin and nitric acid solution reducing the processing time, the amount of acid reagent solution, and evaporation steps.
Two type of separation methods has developed depending on the elements. One is single separation method and the other is multi-separation ones. Single separation method separates a small amount of Sr (~1ug Sr) or Pb (~1ug Pb) only with restricted volume of the resin. This method merits fast recovery of the target element and direct analysis of Sr isotope ratios with MC-ICP-MS. The Pb solution recovered by hydrochloric acid evaporated and dissolved in nitric acid for isotope analysis. Multi-separation method uses a large amount of the resin to separate REE, Sr, and Pb in a row. The REE solution follows further separation of matrix elements with a cation exchange resin to purify rare earth elements. Nd elements purified from REEs with Ln resin.
To reduce organic materials from the Sr resin, a polymeric adsorbent resin is used in the lower layer of the Sr resin. For water samples, it is recommended to use hydrofluoric acid during sample evaporation, because natural water contains silica as a major component and poor separation in the resin. During these methods, the elements recovered up to 95% of Sr and 99 % of Pb of the loaded samples, respectively. The blank levels of Sr and Nd in the separation process were ~10pg and ~20pg, respectively.