Electrochemical Characteristics of Benzanthrone Studied via Cyclic Voltammetry: Charge Transfer Redox Processes

Abstract

The electrochemical behavior of benzanthrone (BA), a known mutagen and carcinogen, and an environmental pollutant widely found in aerosol particulates, was studied on a platinum electrode using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in 0.15 M tetrabutylammonium hexafluorophosphate-acetonitrile solution. At scan rates < 500 mV/s BA exhibited two well defined cathodic and anodic peaks at -1234.909 ± 5.605 mV, and -1158.9 ± 10.88 mV, respectively. The plot of peak currents (i_p) versus ν^1/2 scan rates were linear at ν < 200 mV/s and concentrations 0.5-2.0 mM indicating a diffusion controlled one electron transfer reaction. Higher scan rates (500 - 2000 mV/s) exhibited quasi-reversible reactions with i_pa/i_pc > 1.5. At scan rates > 500 mV/s, a plot of I_p versus ν^1/2 deviates from linearity indicating quasi-reversible redox behavior. For all concentrations studied at scan rates < 200 mV/ the I_pa/I_pc ratios were 1.0650 ± 0.0091. The heterogeneous rate constant, k⁰, of the reversible diffusion-controlled reaction was determined as 3.51 x 10^-5 ± 1.18 x 10^-5 cm s^-1. Via differential pulse voltammetry (DPV) the limit of detection, LOD ( 3s/m), on a bare platinum electrode was determined to be 1.69 x10^-4 ± 1.5 x 10^-5 M (for i_pc) and 3.71 x 10^-4 ± 3.56 x10^-5 M (for i_pa) at 200 mV/s.

Key words:

• Benzanthrone
• heterogeneous rate constant
• diffusion constant