| Design Trials |
Levels (ml) |
Absorbance |
| PDAB reagent |
Ferric Chloride |
At λmax 425 nm |
| T-1 |
1 |
1 |
0.233 |
| T-2 |
2 |
2 |
0.252 |
| T-3 |
3 |
3 |
0.276 |
| T-4 |
1 |
4 |
0.291 |
| T-5 |
2 |
1 |
0.312 |
| T-6 |
3 |
2 |
0.326 |
| T-7 |
4 |
3 |
0.335 |
| T-8 |
5 |
4 |
0.348 |
| T-9 |
6 |
5 |
0.352* |
| T-10 |
4 |
6 |
0.355* |
| T-11 |
5 |
7 |
0.356* |
| T-12 |
6 |
8 |
0.349* |
| T-13 |
7 |
5 |
0.347 |
| T-14 |
8 |
6 |
0.341 |
| T-15 |
9 |
7 |
0.338 |
| T-16 |
7 |
8 |
0.331 |
| T-17 |
8 |
9 |
0.324 |
| T-18 |
9 |
10 |
0.320 |
| T-19 |
10 |
9 |
0.317 |
| T-20 |
10 |
10 |
0.315 |
Aristech (*) value indicated the significant variable (better) optimum level response |