Optimized single-sample sequential separation for stable elements (Fe, Ni, Mo, Nb, and Zr) at trace levels

The paper describes a new sequential separation method that has been developed and optimized for the efficient separation of Fe, Ni, Mo, Nb, and Zr from a single multi-element solution. The protocol employs three types of extraction resins, TK400, ZR, and Ni resins, commercially available from TrisKem International.

TK400 resin is used to separate Fe, Mo, and Nb from Zr and Ni. Then, ZR resin serves two purposes in this protocol: first, to separate Fe, Mo, and Nb from each other, and second, to separate Zr. Ni resin is utilized further to purify Ni from interferences like Co. A pre-filter is applied to eliminate organic impurities and also to purify Ni from interfering elements. The distribution coefficients were determined under batch conditions for the target elements. The dynamic sorption capacity and full dynamic sorption capacity of the sorbents for Fe, Mo, and Nb were evaluated. The method was optimized using varying concentrations of the target elements and demonstrated high chemical recoveries (71 ± 3% to 98 ± 4%) with reproducibility (RSD <6,6%).

In this study, we developed a single simple sequential protocol that provides a selective approach for separating Fe, Ni, Mo, Nb, and Zr, major and minor alloying elements in steel, using commercially available resins.