Ionophore N, N’–Ethylene-bis-(Salicylideneaminato) copper (II) has been synthesized and
characterized by IR and 1H NMR spectroscopy. Poly (vinyl chloride) based polymeric films of this ionophore along with cation discriminator (CTAB) and different plasticizers (dibutyl phthalate, dioctyl phthalate, 1-chloronapthalene and tri-n-butyl phosphate) were prepared and investigated as Nitrate ion sensors. Among all the different sensors fabricated, the one with membrane composition as I (7 mg): PVC (31 mg): DBP (60 mg): CTAB (2 mg) exhibited best characteristics. This sensor functions admirably over a wide concentration range 1.0×10−6–1.0×10−2 M with Nernstian compliance (59.8 mV per decade of concentration) between pH range 2.5–9.2 with a rapid response time of 13s. The sensor showed a lower detection limit 1.58×10-6 M. The selectivity coefficient values as determined by the fixed interfering method (FIM) show that the Nitrate ion has excellent selectivity over several anions. The sensor shows satisfactory time span of 2 months with great reproducibility while used continuously daily for 4 hrs. The sensor has been successfully utilized in the determination of nitrate ion concentration in different water samples.
Determination of Volume Conductivity of Thin Polymeric Films Using Corona Triode, When the Current through the Sample Depends Quadratically on Grid Potential
