Electrochemical degradation and determination of 4-nitrophenol using multiple pulsed amperometry at graphite based electrodes [articol]

Abstract

The electrochemical degradation and determination of 4-nitrophenol (4-NP) by multiple pulsed amperometry (MPA) using rotating spectral graphite disc (SG) and expanded graphite-epoxy composite (EG-Epoxy) electrodes is reported.The MPA performance for 4-NP degradation was assessed as function of time for both electrodes, the best results were achieved for SG electrode. The optimal MPA parameters at the both types of graphite based electrodes were establised for 4-NP detection , i.e. the detection potential was 1.1 V ( versus Ag/AgCl) for 50 ms detection time and 1.4 V (versus Ag/AgCl) oxidation potential as clean potential for 150 ms clean time. The proposed method showed the better analytical performance for EG-Epoxy electrode for the determination 4-NP, with a linear range of 0.2 – 1 mM, detection limits of 0.05 - 0.1 mM and recovery degree of 92.4 – 94.6 %. The application of this method to a drinking water spiked with various quantities of nitrophenol was demonstrated and validated using UV photometric determination method at λ=398 nm for 4-NP.