Table 1. Optimized parameters for HPLC and ICP-MS conditions.
| HPLC | |
|---|---|
| Column | Agilent Bio WAX (4.6 mm i.d. × 50 mm) |
| Mobile phase | 50 mmol L–1 CH3COONH4, 2 mmol L–1 PDCA (pH 6.80) |
| Flow rate | 0.6 mL min–1 |
| Column temperature | Room temperature |
| Injection volume | 10 μL |
| ICP-MS | |
| RF power | 1200 W |
| Plasma gas | 15 L min–1 |
| Auxiliary gas | 1.0 L min–1 |
| Carrier gas | 1.0 L min–1 |
| Sampling depth | 5.5 mm |
| Spray chamber temperature | 2°C |
| Injector | 2.5 mm i.d. |
| CRC gas | He 4.3 mL min–1 |
| KED | +3 V |
| Monitored isotope (m/z) | 52Cr, 35Cl |
| Integration time | 1 s for 52Cr, 0.001 s for 35Cl |
CRC, collision/reaction cell; HPLC, high-performance liquid chromatography; ICP-MS, inductively coupled plasma-mass spectrometry; KED, kinetic energy discrimination; PDCA, 2,6-pyridinedicarboxylic acid.