Optimization of a cerium(IV) carbon paste electrode based on 2-hydroxy-1, 4- naphthoquinon / MWCNTs by using experimental design

Box–Behnken designs were used as experimental design method to optimize the influence of ingredients of membrane on the electrode performance. A nanocomposite was designed by using 2-hydroxy-1, 4-naphthoquinon as ion carrier with multi-wall carbon nanotubes (MWCNTs), in order to determination of Ce(IV). Box–Behnken response surface was led to find a model for optimizing the response. The best performance was obtained with 5 % wt of lawsone, 10 % wt of MWCNTs, 20 % wt of paraffin oil and 65 % wt of graphite powder. The optimized membrane electrode shows a Nernstian response (15.08±0.2 mV decate-1) toward Ce(IV) ions in linear range from 1.0×10-7 to 1.0×10-2 mol L-1 with a detection limit of 5.0×10-8 mol L-1. The proposed sensor was employed in pH range of 4 to 8 with a fast response time (10 s).