A comparative study between two different conventional working electrodes for detection of Δ9-tetrahydrocannabinol using square-wave voltammetry: a new sensitive method for forensic analysis

Journal of the Brazilian Chemical Society

Marco A. Balbino²  Izabel C. Eleotério²  Laura S. De Oliveira²  Matheus M. T. De Menezes²  José Fernando De Andrade²  Antônio José Ipólito¹  Marcelo F. De Oliveira² 

[1] ,Universidade de São Paulo Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto Departamento de QuímicaRibeirão Preto SP ,Brazil

关键词: square-wave voltammetry;    tetrahydrocannabinol;    forensic science;    marijuana;   

DOI  :  10.5935/0103-5053.20140040

来源: SciELO

【 摘 要 】

Marijuana is a widely consumed illicit drug. Therefore, drug dealers have sought new ways to mask its forensic (spot test) analysis. In this article we describe a methodology for delta-9-tetrahydrocannabinol (Δ9-THC) detection by square-wave voltammetric (SWV) analysis in organic medium (N,N-dimethylformamide) using tetrabutylammonium tetrafluoroborate (TBATFB) as supporting electrolyte, and glassy carbon and platinum disc as working electrode. Applying a potential of -0.5 ± 0.01 V vs. Ag/AgCl, KCl(sat), we detected a well-defined anodic peak current after the pre-concentration step; Δ9-THC detection presented linear dependence at concentrations ranging from 1.0 × 10-9 mol L-1 to 2.2 × 10-8 mol L-1, with a linear correlation coefficient 0.999 and a detection limit of 6.2 × 10-10 mol L-1, using the glassy carbon disc working electrode. These results confirm that optimized SWV technique using glassy carbon disc working electrode enables qualitative analysis of Δ9-THC at concentrations higher than 1.0 nmol L-1.

【 授权许可】

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