Table 2 Reagent types and volumes, temperature and time attempted during optimization of digestion of 0.5 g fennel fruit
No. | Reagent volume (mL) | Temperature (°C) | Time (min) | Results | ||
|---|---|---|---|---|---|---|
HNO3 | HClO4 | Total | ||||
1 | 1 | 3 | 4 | 270 | 180 | Yellow |
2 | 1.5 | 2.5 | 4 | 270 | 180 | Lightly yellow |
3 | 2 | 2 | 4 | 270 | 180 | Almost clear |
4 | 2.5 | 1.5 | 4 | 270 | 180 | Clear solution |
5 | 3 | 1 | 4 | 270 | 180 | Clear solution |
6 | 3.5 | 0.5 | 4 | 270 | 180 | Almost clear |
7 | 2.5 | 1.5 | 4 | 120 | 180 | Yellow |
8 | 2.5 | 1.5 | 4 | 150 | 180 | Lightly yellow |
9 | 2.5 | 1.5 | 4 | 180 | 180 | Almost clear |
10 | 2.5 | 1.5 | 4 | 210 | 180 | Clear solution |
11 | 2.5 | 1.5 | 4 | 240 | 180 | Clear solution |
12 | 2.5 | 1.5 | 4 | 270 | 180 | Clear solution |
13 | 2.5 | 1.5 | 4 | 270 | 105 | Light brown with suspension |
14 | 2.5 | 1.5 | 4 | 270 | 120 | Yellow |
15 | 2.5 | 1.5 | 4 | 270 | 135 | Lightly yellow |
16 | 2.5 | 1.5 | 4 | 270 | 150 | Clear solution |
17 | 2.5 | 1.5 | 4 | 270 | 165 | Clear solution |
18 | 2.5 | 1.5 | 4 | 270 | 180 | Clear solution |