Table 2:
Variables and levels for the experimental design.
Variable
Level 1
Level 2
Level 3
Flow rate HCl (mL min
−1
)
1.3
2.8
5.9
Flow rate NaBH
4
(mL min
−1
)
1.7
3.7
4.5
HCl% (v/v)
5
15
30
NaBH
4
(% (m/v))
0.1
0.2
0.5