Table 2 Optimization of volume ratio of the reagents for digestion of sample mass (0.5 g) at 300°C for 4 h
From: Levels of selected metals in leaves of Cannabis sativa L. cultivated in Ethiopia
No. | Total volume (mL) | Volume ratio (mL) HNO3: HCl:H2O2:HClO4 | Observation |
|---|---|---|---|
1 | 4 | 2:0:1:1 | Pale yellowish solution with small residue |
2 | 4 | 2:1:0:1 | Yellowish solution with residue |
3 | 4 | 2:0.5:0.5:1 | Pale yellow solution with residue |
4 | 5 | 2:2:0:1 | Pale yellow solution with residue |
5 | 5 | 2:1:1:1 | Yellow solution with residue |
6 | 5 | 3:1:1:0 | Deep yellow solution with small residue |
7 | 6 | 3:1:1:1 | Yellow solution with small residue |
8 | 6 | 3:2:0.5:0.5 | Colorless solution but not clear |
9 | 7 | 4:1:1:1 | Pale yellow solution with small suspension |
10 | 7 | 4:2:0.5:0.5 | Yellow solution with residue |
11 | 8 | 5:1:1:1 | Slightly clear and colorless solution with residue |
12 | 8 | 5:2:0.5:0.5 | Pale yellow solution with small suspension |
13 | 9 | 6:2:0:1 | Slightly clear and colorless solution with residue |
14 | 9 | 7:0:1:1 | Slightly clear and colorless solution with small residue |
15 | 10 | 9:0:0:1 | Clear and colorless solution |
16 | 10 | 9:0.5:0:0.5 | Clear and colorless solution |
17 | 10 | 9:0:0.5:0.5 | Clear and colorless solution |