Electrochemical characterization of luminol and its determination in real samples

Abstract

The electrochemical behavior of luminol, an important molecule in forensic science, was studied in Britton-Robinson buffer solution (pH 2-pH 13) at a glassy carbon electrode using cyclic voltammetry and differential pulse voltammetry techniques. Luminol showed a well-defined and irreversible oxidation peak at 0.33 V (vs. Ag/AgCl) in 0.05 mol L-1 Britton-Robinson buffer solution at pH 12. The electrooxidation process of luminol was adsorption-controlled and irreversible over the pH range studied (2.0-13). The differential pulse voltammetric determination of luminol was carried out. Under optimal conditions, the glassy carbon electrode displayed a linear response over the range from 1.8 x 10(-8) to 4.5 x 10(-4) mol L-1 luminol concentration, and statistical data were evaluated. A commercially available real sample that contained luminol was analyzed according to this method. The luminol percentage of the sample was obtained as 21.2 (+/- 0.4)%.