New Ni(II) Ion-Selective Electrode Based on the N-S Schiff Base Ligand as Neutral Carrier in PVC Matrix

摘要

A nickel(II) [Ni(II)] ion-selective electrode was prepared by incorporating a new N-S Schiff base ligand, glyoxal-bis(S-benzyldithiocarbazate) (GBSB), as a neutral carrier into the PVC matrix. The proposed electrode exhibits an excellent near-Nernstian response for Ni2 ions, ranging from 2.8x10-7 to 1.0x10-1mol/L with a detection limit of 1.2x10-7mol/L and a slope of 31.9 /- 0.3mV/dec in pH 4.0 nitrate buffer solution at 25 degrees C. It has an appropriate response time and suitable reproducibility and can be used for at least 3 months. The operational pH range of the proposed electrode is 4.0-7.5. The response mechanism is discussed in view of the alternating current (AC) impedance technique. In addition, the electrode was successfully used as an indicator electrode in potentiometric titration of Ni2 ion and in the direct determination of Ni2 ion in milk power and chocolate samples.

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