Cathodic Stripping Voltammetry (CSV) Analysis of Reactive Black 5 (RB5) Dye Using Hanging Mercury Electrode (HMDE) in Basic Medium

Abstract

A CSV analysis of Reactive Black 5 Dye (RB5) in Britton-Robinson buffer (BRB) using a hanging mercury drop electrode (HMDE) is described. CSV was carried out by cathodic potential scan through a potential range of −100 to −1000 mV without any accumulation time. The effect of the pH of BRB solution on the peak height (I_p) and peak potential (E_p) of RB5 dye were studied. Results showed that in pH 8.0–12.0, three peaks at −417 to −564 mV, −661 to −772 mV and −774 to −879 mV respectively for the first, second and third reduction peak were observed. All potentials were referred against Ag/AgCl as reference electrode. The BRB solution at pH 9.0 was selected as the best condition for the detection of RB5 dye in basic medium which gave maximum I_p. Effects of the scan rate (v), accumulation time (t_acc), accumulation potential (E_acc), pulse amplitude and equilibrium time were also studied. Results showed that the optimum parameters for CSV analysis of RB5 dye in BRB solution at pH 9.0 were v: 15 mV/s, t_acc: 30 s, E_acc: −100 mV and pulse amplitude: 150 mV. By this optimization procedure, the I_p was increased from 13 to 173 nA for the second reduction peak which was considered as the well characteristic peak for analysis. Future works should validate this technique using those optimum parameters before being used for a routine analysis of RB5 dye in environmental samples.