Determination of Cocaine by Square Wave Voltammetry with Carbon Paste Electrodes
Keywords:Forensic chemistry, Cocaine, Voltammetry, Carbon paste electrode
AbstractWe compare the electrochemical behavior of cocaine hydrochloride (in acidic medium) and its free base form (in acetonitrile) by a simple, cheap, and fast square wave voltammetry method for cocaine analysis based on carbon paste electrodes without chemical modification. The electrodes performed better than the electrodes obtained for analysis on commercial screen-printed electrodes, which we also tested here. We conducted the analyses in aqueous solution containing 0.1 mol/L NH4ClO4 as supporting electrolyte. For cocaine in acidic medium, the linear correlation coefficient, the LOD, and the LOQ were 0.996, 4.66 10^(-6) mol/L, and 1.55 10^(-5) mol/L, respectively. For cocaine in acetonitrile medium, the linear correlation coefficient, the LOD, and the LOQ were 0.994, 9.77 10^(-6) mol/L, and 3.26 10^(-5) mol/L, respectively. The specificity of the methodology is advantageous when the response of different interfering substances analyzed in this work (lidocaine, procaine, caffeine and phenacetine) is concerned.
How to Cite
Pedro Henrique Barros Oliva, Juliana Midori Toia Katayama, Érica Naomi Oiye, Bruno Ferreira, Maria Fernanda Ribeiro, Antônio José Ipólito, José Fernando de Andrade, & Marcelo Firmino de Oliveira. (2019). Determination of Cocaine by Square Wave Voltammetry with Carbon Paste Electrodes. Brazilian Journal of Forensic Sciences, Medical Law and Bioethics, 8(3), 149–164. https://doi.org/10.17063/bjfs8(3)y2019149