Fig. 2.

A series of Cu elution protocols which differ in the amount of AG-MP1 resin and the solution used, including an HCl-based purification similar to published methods (A), an isopropanol-based eluent (B), a 15 M acetic acid eluent which is slow (C), a 11 M acetic acid eluent with high eluent volumes (D), a 11 M acetic acid eluent on a larger resin volume (0.5 mL; E), and the final optimized protocol (F). Results are presented for the recovery of multiple elements (left) and recovery of Cu in a log scale (right). Experiments were performed with 0.5 mL of the eluent with 100 ng of a multi-element mixture, except for B in which elements were dissolved in 3 mL eluent, and D which contained 50 ng Ti and Cu. Error bars in D reflect duplicate experiments