A new voltammetric method for the simultaneous determination of the antioxidants TBHQ and BHA in biodiesel using multi-walled carbon nanotube screen-printed electrodes

• Published in: Fuel (Guildford) Vol. 105; pp. 306 - 313
• Main Authors: Caramit, Ricardo Pini, de Freitas Andrade, Adriana Garabini, Gomes de Souza, João Batista, de Araujo, Tatiane Alfonso, Viana, Luiz Henrique, Trindade, Magno Aparecido Gonçalves, Ferreira, Valdir Souza
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-03-2013; Elsevier
• Subjects: Antioxidants; Applied sciences; BHA; Biodiesel; Cationic; Electroanalysis; Electrodes; Electrolytes; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fuels; Methyl alcohol; Multi wall carbon nanotubes; Screen-printed electrodes; Surfactants; Antioxidants; Electroanalysis; Surfactants; Biodiesel; Screen-printed electrodes; Diesel fuel; HPLC chromatography; Carbon electrode; Carbon nanotubes; Biofuel; Liquid chromatography; Surfactant; Antioxidant; Dilution; Detection; Performance; Methanol
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2012.06.062

Cyclic voltammograms obtained on SPE–MWCNT surface for, (a) blank: BR buffer 0.04molL−1 (pH 2.0) containing 2.0% of methanol; (b) TBHQ 2.0×10−5molL−1; (c) BHA 2.0×10−5molL−1; (d) mixture of TBHQ and BHA in the concentration of 2.0×10−5molL−1. Scan rate of 150mVs−1. [Display omitted]
► Use of modified screen-printed electrodes to simultaneous detection of antioxidants. ► Methodology for simultaneous determination of TBHQ and BHA in micelar medium. ► The electrochemical system was easily adapted for on-site analysis.
An electroanalytical method for the simultaneous detection and quantification of tert-butylhydroquinone (TBHQ) and butyl hydroxyanisole (BHA) in biodiesel was developed using a voltammetric technique and screen-printed electrodes. The supporting electrolyte solution was composed of Britton–Robinson buffer (0.04molL−1) containing methanol (2.0%) and the cationic surfactant cetyltrimethylammonium bromide (CTAB). In the presence of CTAB, the peak current intensity and voltammetric resolution increased significantly for both studied antioxidants. Using the optimized conditions, the method presented a linear response in the concentration range of 5.0×10−7–1.0×10−5molL−1 for TBHQ (r=0.999) and BHA (r=0.999) with detection limits of 3.40×10−7molL−1 and 1.76×10−7molL−1, respectively. The proposed method was successfully applied for the quantification of TBHQ and BHA in biodiesel samples after a simple and rapid dilution with recoveries from 97.90% to 110.0% and 91.90% to 101.0%, respectively. The obtained results were satisfactory when compared with those obtained using high-performance liquid chromatography (HPLC). Additionally, the proposed method can be easily adapted for on-site analysis.