Lead(II) Selective PVC Membrane Electrode Based on Zinc Complex of Salicylaldehyde Semicarbazone as an Ionophore ZSSC

A polymeric membrane based lead selective electrode was developed by using zinc complex of salicylaldehyde semicarbazone. The best performance was recorded with amembrane composition of PVC: DBP: Ionophore: NaTPB as 33: 58: 4: 5 (w/w %). The Nernstian slope calculated from the calibration curve for Pb2+ sensor was 29.2 mV/ decade. The detection limit of the sensor was 3.10×10-9 M, in the linear concentration range of 1.0×10- 2-1.0×10-8 M. It was relatively fast response time (<10s for concentration ≥1.0×10-3 and <15s for concentration of ≥1.0×10-6 M) and can be used for 9 months without any considerable divergence in potentials. The proposed sensor exhibit relatively good selectivity and high sensitivity for lead(II) as other mono, di and trivalent cations and can be used in a pH range of 2.0-10.5. It was used successfully as an indicator electrode in potentiometer titrations and also determines the concentration of lead in water of Yamuna River at different sites of Delhi.