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 1
Factors in BBD and their levels.
| ā | Bismuth concentration (X1, ppb) | pH (X2) | Oxine concentration (X3, ppb) |
| Central level (0) | 600 | 6 | 581 | High level (+1) | 1000 | 8 | 1016 | Low level (ā1) | 200 | 4 | 145 |
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