Table 2.
Parameters used for digestion and analysis of total selenium concentration.
| Methods | Setting | |
|---|---|---|
| Microwave system parameter: | ||
| Estimated sample weight | 0.5 g | |
| Starting pressure | 40 bar | |
| Pressure | 160 bar | |
| Step time | Step 1: 25–220 °C, 20 min Step 2: 220 °C, 20 min |
|
| Cooling temperature | 50 °C | |
| Pressure release rate | 8.0 bar/min | |
| ICP-QQQ-MS parameter: | He (99.999%) mode | O2 (99.999%) mode |
| Radio frequency (RF) power | 1550 W | |
| Sampling depth | 8 mm | |
| Carrier gas, flow rate | 1.05 L/min | |
| Makeup gas, flow rate | 0.2 L/min | |
| 3 mL/min | 30% | |
| Monitor masses | 77Se, 78Se, 82Se, 78Se16O+, 80Se16O+, 82Se16O+ | |