Application of 2-(benzyliminomethyl)-6-methoxy-4-(4-methoxyphenyl-azo)phenol in construction of ion-selective PVC membrane electrode for determination of copper (II) in mineral water sample

The potentiometric characteristics of a new Cu2+-selective electrode based on 2-(benzyliminomethyl)-6-methoxy-4-(4-methoxyphenyl-azo) phenol as an efficient ionophore has been evaluated. The effects of influential parameters on the potentiometric responses such as the amount of plasticizer, the amount of ionophore, pH of the sample solution, and the effect of coexisting ions on the electrode signal were subsequently investigated. The selectivity of the electrode was assessed by calculating the selectivity coefficients using the matched potential method. The optimum ratio of the amount of materials required for the preparation of the electrode was found to be 1.7: 32.1: 64.2: 2.0 corresponding to carboxylated PVC, dimethyl sebacate as solvent mediators, potassium tetrakis (p-chlorophenyl) borate as the anion localizing agent, and ionophore, respectively. The electrode had a fast response (7s) as well as a satisfactory Nernstian slope (29.26 +/- 0.91 mV/decade) to Cu2+ over a wide concentration range of 2.0x10(-6)- 5.0x10(-2) M with a low detection limit of 5.9x10(-7) M. The developed sensor was successfully used for the potentiometric titration of Cu2+ ion with EDTA and subsequently, efficient determination of this metal ion in a mineral water sample was performed.