Design and Construction of High-Sensitive and Selective Zinc(II) Electrochemical Membrane Sensor Based on N,N-bis (2hydroxy-4-metoxybenzaldehyde)-2,6-di amino pyridine

In this work, a novel Zn (II) membrane sensor based on N, N-bis (2hydroxy -4-metoxybenzaldehyde)-2, 6-di amino pyridine (L1) is presented. The electrode shows a good selectivity for Zn (II) ions with respect to most common cations including alkali, alkaline earth, transition and heavy metal ions. Conductance study of L1 to Zinc and some other metal ions were carried out and confirmed selectivity toward Zn (II) ions. The electrode comprises 7 % L1, 29 % PVC, 60 % NPOE and 4 % NaTPB. The sensor displays a linear dynamic range between 1.0x10(-7) and 1.0x10(-1) M, with a nice Nernstian slope of 29.5 +/- 0.5mV per decade and a detection limit of 7.9x10(-8) M. The potentiometric response is independent of pH in the range of 4.5-10. The proposed sensor posses the advantages of short response time, low detection limit and wide linear dynamic range in comparison with former ones. The electrode can be used for at least four month without any considerable divergence in the potentials. It was used as an indicator electrode in the potentiometric titration of Zn (II) ions with EDTA. It was also applied for determination of Zn2+ in some soil samples and in electroplating industrial samples.