A differential pulse voltammetric (DPV) method was developed for the determination of 4-nitrophenol (4-NP) at a newly developed silver amalgam paste electrode (AgA-PE) in Britton-Robinson buffer pH 3.0. The electrode is based on a disposable plastic pipette tip filled with paste amalgam based on a mixture of mercury and fine silver powder (9:1, w/w).
The experimental parameters, such as pH of Britton-Robinson buffer and activation and regeneration potential of the electrode surface were optimized. The reduction peak current dependences were linear for the concentration of 4-NP from 0.2 to 100 µM.
The method showed reproducible results with RSD (n = 45) of 1.7%. The limit of determination (LOD) was 0.3 µM.
The method was successfully applied for the direct determination of 4-NP in drinking water.