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

Oliveira, Marcelo F. de¹  Núcleo de Perícias Criminalísticas de Ribeirão Preto, Ribeirão Preto, Brazil¹  Universidade de São Paulo, Ribeirão Preto, Brazil¹  Andrade, José Fernando de¹  Ipólito, Antônio José¹  Menezes, Matheus M. T. de¹  Balbino, Marco A.¹  Oliveira, Laura S. de¹  Eleotério, Izabel C.¹ 

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

DOI  :  10.5935/0103-5053.20140040

学科分类：化学（综合）

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】

Unknown