Differential pulse voltammetry as an alternate technique for over oxidation of polymers: Application of electrochemically synthesized over oxidized poly (Alizarin Red S) modified disposable pencil graphite electrodes for simultaneous detection of hydroquinone and catechol

Abstract

We have demonstrated the effectiveness of differential pulse voltammetry (DPV) as a technique for the preparation of an over oxidized poly (Alizarin Red S) modified disposable pencil graphite electrode (o-PARS/PGE). The modified electrodes were analyzed using spectroscopic, electron microscopic and electrochemical techniques. As an application, the o-PARS/PGE was used for the simultaneous determination of hydroquinone (HQ) and catechol (CC) using DPV and double potential pulse chronoamperometry (DPCA). It was found that o-PARS/PGE exhibited an excellent electrocatalytic activity and differentiating ability towards HQ and CC with a peak separation of 100mV. Under the optimized conditions, the calibration curves showed linearity in the range of 0.5–600μM for both the isomers with a limit of detection (LOD, 3σ/m) of 0.452μM and 0.122μM for HQ and CC respectively. The practical viability of the fabricated electrode was demonstrated by the successful determination of HQ and CC in a tap water sample with satisfactory recovery. On comparison with other commonly employed electrochemical techniques for over oxidation, o-PARS/PGE prepared using DPV was found to be more sensitive.