First Order Derivative of Differential Pulse Voltammetry for the Selective and Sensitive 4-Nitrophenol Determination in the Presence of 2-Nitrophenol at a Bare Graphite Electrode

Derivative processing of the signal obtained by differential pulse voltammetry was applied in this work as a simple strategy to achieve the sensitive and selective 4-nitrophenol (4-NP) determination in the presence of the interfering compound 2-nitrophenol (2-NP). The derivative voltammogram displayed a well-defined and fully separated 4-nitrophenol anodic peak, which was used for its quantification in two linear concentration ranges extended up to 10 mu mol L-1 and up to 100 mu mol L-1. A LOD as low as 0.1 mu mol L-1 (S/N=3) was achieved using spectroscopic graphite electrode without any modification. The accuracy of the 4-NP determination in the presence of 2-NP, assessed by spike-and-recovery experiments was found to be satisfactory. 4-NP determination was not affected by the presence of a range of structurally similar phenolic compounds. The derivative processing of the signal obtained by differential pulse voltammetry allowed the selective 4-ntrophenol determination in the presence of the interfering compound 2-ntrophenol using its anodic peak, which remains intact.image