Details

Autor(en) / Beteiligte

• Oiye, Érica Naomi
• Figueiredo, Natalia Biziak de
• Andrade, José Fernando de
• Tristão, Heloisa Maria
• Oliveira, Marcelo Firmino de

Titel

Voltammetric determination of cocaine in confiscated samples using a cobalt hexacyanoferrate film-modified electrode

Ist Teil von

• Forensic science international, 2009-11, Vol.192 (1), p.94-97

Ort / Verlag

Kidlington: Elsevier Ireland Ltd

Erscheinungsjahr

2009

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Abstract In this work, a fast, non destructive voltammetric method for cocaine detection in acetonitrile medium using a platinum disk electrode chemically modified with cobalt-hexacyanoferrate (CoHCFe) film is described. The deposition of CoHCFe film at platinum disk (working electrode) was carried out in aqueous solution containing NaClO4 at 0.1 mol L−1 as supporting electrolite. Stability studies of the film and subsequent voltammetric analysis of cocaine were made in acetonitrile medium with NaClO4 at 0.1 mol L−1 as supporting electrolite. A reversible interaction between cocaine and CoHCFe at the film produces a proportional decrease of original peak current, due to the formation of a complex between cocaine and cobalt íons, with subsequent partial passivation of the film surface, being the intensity of current decrease used as analytical signal for cocaine. A linear dependence of cocaine detection was carried out in the range from 2.4 × 10−4 to 1.5 × 10−3 mol L−1 , with a linear correlation coefficient of 0.994 and a detection limit of 1.4 × 10−4 mol L−1 . The analysis of confiscated samples by the proposed method indicated cocaine levels from 37% to 95% (m/m) and these results were validated by comparison to HPLC technique, being obtained good correlation between both methods.