Determination of Nitrate by Electrochemical impedance spectroscopy and potentiometric Techniques

Ionophore derivative anion receptor has been tested as electroactive material for the development of anion selective electrodes. The receptor was incorporated in plasticized poly (vinyl chloride)membranes of different compositions. The membrane that provided the best response and selectivity towards nitrate was selected to develop a new nitrate-selective electrode. In this work a new strategy for optimizing membrane components by electrochemical impedancespectroscopy (EIS) is used. The performance of this electrode was investigated using potentiometric and EIS techniques. The electrode exhibited a Nernstian response over the nitrate concentration range of 1.0×10-7 to 1.0×10−1 M with a slope of 59.5 mV/decade by potentiometrictechnique. It showed good selectivity to nitrate relative to many common anions. While using the EIS technique, the linear concentration range was 1.0×10-8 to 1.0×10−1 M and the pH range increased to 4.0-10.0. The proposed electrode was applied to the determination of nitrate in wastewaters.

کلیدواژه ها:

Ion selective electrode ، Potentiometric ، nitrate ، Membrane ، Plasticizer ، Additive