Determination of Cocaine by Square Wave Voltammetry with Carbon Paste Electrodes

Authors

  • 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

DOI:

https://doi.org/10.17063/bjfs8(3)y2019149

Keywords:

Forensic chemistry, Cocaine, Voltammetry, Carbon paste electrode

Abstract

We 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.

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Published

2019-06-04

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

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Original Article