TABLE 2.
Ion chromatography procedure for group separation of REE in this study, modified from Tanaka et al. (2018).
| Major composition removal (HCl column) | ||
| Resin: 8 mL AG50W-X8 (cation) 200–400 mesh | ||
| Step | Eluent (UP HCl) | Volume (mL) |
| Column wash | 6 N HCl | 20 |
| Column wash | MillQ water | 20 |
| Column conditioning | 2 N HCl | 5 |
| Load sample | 2 N HCl | 4 |
| Discard major ions | 2 N HCl | 35 |
| Collect Sr | 2 N HCl | 35 |
| Collect REE | 6 N HCl | 40 |
| Colum wash (re-use) | 6 N HCl | 20 |
| Dry 6 N HCl collected REE fraction | ||
| Second column procedure: group separation of REE to eliminate oxide ions for MC-ICP-MS | ||
| Resin: 0.8 mL AG50W-X8 (neutralized by NH4OH) 200–400 mesh | ||
| Step | Eluent (HIBA) | Volume (mL) |
| Column wash | 0.3 M HIBA | 5 |
| Column wash | MillQ water | 5 |
| Column conditioning | 0.05 M HIBA | 5 |
| Sample loading | 50 μL DIW | |
| Column wash | 0.045 M HIBA | 0.5 |
| Collect HREE | 0.09 M HIBA | 9 |
| Collect MREE | 0.15 M HIBA | 15 |
| Collect LREE | 0.3 M HIBA | 20 |
| Discard resin and wash column for the new sample | ||