Electrocatalytic reduction and determination of p-nitrophenol on acetylene black paste electrode coated with salicylaldehyde-modified chitosan

A novel method has been developed for the determination of p-nitrophenol (p-NP), which was based on the enhanced electrochemical response of p-NP at an acetylene black paste electrode coated with salicylaldehyde-modified chitosan (denoted as S-CHIT/ABPE). In 0.2 mol L-1 HCl solution, p-NP yielded a sensitive reduction peak at -0.348 V. Compared with the poor response at conventional carbon paste electrode, S-CHIT/ABPE remarkably increased the peak current of p-NP. All the experimental conditions, which influence the electrochemical response of p-NP, were studied and the optimum conditions were achieved. Finally, a sensitive and simple voltammetric method with a good linear relationship in the range of 8.0 x 10(-8) mol L-1 to 2.0 x 10(-6) mol L-1 was developed for the determination of p-NP. The detection limit (S/N = 3) was also examined and a low value of 3.0 x 10(-8) mol L-1 for 120 s accumulation was obtained. The method has been successfully applied to the determination of p-NP in water samples with good recovery in the range of 96-104%. (C) 2012 Elsevier B.V. All rights reserved.