The present study describes a new approach for the investigation of electrocatalytic oxidation of sulphide using a pencil graphite electrode modified with hematoxylin (PGE/HMT). Adsorption procedure was used for the preparation of the modified electrodes. It was observed that PGE/HMT showed a significant electrocatalytic activity toward sulphide oxidation. Cyclic voltammetric studies showed that the peak potential of sulphide shifted from +480 mV at bare PGE to +220 mV at PGE/HMT. The electrocatalytic currents obtained from amperometric measurements at +200 mV versus Ag/AgCl/KClsat and at pH 8.0 BR buffer solution containing 0.1 M KCl were linearly related to the concentration of sulphide. The calibration graph consisted of a linear segment of 1-200 mu M with a detection limit of 0.4 mu M (based on 3s(b)). The proposed method was successfully applied to the determination of sulphide in waste waters and was compared with the spectrophotometric method. (C) 2012 Elsevier B.V. All rights reserved.
The present study describes a new approach for the investigation of electrocatalytic oxidation of sulphide
using a pencil graphite electrode modified with hematoxylin (PGE/HMT). Adsorption procedure was
used for the preparation of the modified electrodes. It was observed that PGE/HMT showed a significant
electrocatalytic activity toward sulphide oxidation. Cyclic voltammetric studies showed that the peak
potential of sulphide shifted from +480 mV at bare PGE to +220 mV at PGE/HMT. The electrocatalytic
currents obtained from amperometric measurements at +200 mV versus Ag/AgCl/KClsat and at pH 8.0 BR
buffer solution containing 0.1 M KCl were linearly related to the concentration of sulphide. The calibration
graph consisted of a linear segment of 1–200 M with a detection limit of 0.4 M (based on 3sb). The
proposed method was successfully applied to the determination of sulphide in waste waters and was
compared with the spectrophotometric method.