Inexpensive Bismuth-Film Electrode Supported on Pencil-Lead Graphite for Determination of Pb(II) and Cd(II) Ions by Anodic Stripping Voltammetry

Table 2

Experiments of 2³ factorial design and response values.

Order	C; (mg L^-1)	Ed; (V)	td; (s)	I; (nA)	I; (nA)
1	150	-1.50	100	5.31	7.92
2	150	-1.50	250	16.8	29.3
3	250	-1.50	100	4.71	9.26
4	150	-1.10	250	18.4	29.3
5	250	-1.50	250	7.02	14.9
6	250	-1.10	250	6.97	14.9
7	150	-1.10	100	2.75	3.23
8	250	-1.10	100	1.79	6.37