Research Article

Voltammetry Determination of Pb(II), Cd(II), and Zn(II) at Bismuth Film Electrode Combined with 8-Hydroxyquinoline as a Complexing Agent

Table 3

Analysis of variance (ANOVA) for B-B design.

TermsCoefficient Ipc,PbCoefficient Ipc,CdCoefficient Ipc,Zn

Constant1.95≤0.0012.00≤0.0012.00≤0.001
x10.080.0030.080.0610.080.042
x20.19≤0.0010.220.0010.210.001
x30.120.0010.160.0060.150.005
–0.35≤0.001–0.370.001–0.36≤0.001
–0.44≤0.001–0.44≤0.001–0.45≤0.001
–0.19≤0.001–0.180.014–0.190.008
x1 · x20.000.9090.000.9600.000.912
x1 · x30.001.0000.001.0000.001.000
x2 · x30.110.0040.130.0470.110.050
Regression
Lack of fit