Table 4 MPFD experimental design: 5 levels for 3 components. V = 25 mL of ammonia buffer solution at pH = 10 and 0.033 g of PAN-CC
From: Low-cost, disposable colourimetric sensors for metal ions detection
Variable levels | Design of experiments | ||||
|---|---|---|---|---|---|
Level | c (μM) | [Co] | [Ni] | [Zn] | |
− 2 | 0 | 1 | 0 | 0 | 0 |
− 1 | 3.5 | 2 | 0 | − 2 | − 1 |
0 | 4.5 | 3 | − 2 | − 1 | − 2 |
1 | 5.5 | 4 | − 1 | − 2 | 2 |
2 | 7 | 5 | − 2 | 2 | 2 |
6 | 2 | 2 | 0 | ||
7 | 2 | 0 | − 1 | ||
8 | 0 | − 1 | 2 | ||
9 | − 1 | 2 | − 1 | ||
10 | 2 | − 1 | 1 | ||
11 | − 1 | 1 | 1 | ||
12 | 1 | 1 | 0 | ||
13 | 1 | 0 | 2 | ||
14 | 0 | 2 | 1 | ||
15 | 2 | 1 | 2 | ||
16 | 1 | 2 | − 2 | ||
17 | 2 | − 2 | − 2 | ||
18 | − 2 | − 2 | 0 | ||
19 | − 2 | 0 | 1 | ||
20 | 0 | 1 | − 2 | ||
21 | 1 | − 2 | 1 | ||
22 | − 2 | 1 | − 1 | ||
23 | 1 | − 1 | − 1 | ||
24 | − 1 | − 1 | 0 | ||
25 | − 1 | 0 | − 2 | ||