Voltammetric determination of tert-butylhydroquinone in biodiesel using a carbon paste electrode in the presence of surfactant.
This paper reports an electroanalytical method developed for determining the antioxidant tert-butylhydroquinone (TBHQ) in biodiesel, based on the enhancement effect of cetyltrimethylammonium bromide (CTAB). In pH 6.5 Britton-Robinson buffer, a poorly defined oxidation peak was observed for TBHQ at a carbon paste electrode (CPE). In the presence of low concentrations of CTAB, however, the oxidation peak current was markedly increased. Several parameters were studied and optimized for the development of this methodology, and under optimal conditions the oxidation peak current was proportional to TBHQ concentration in the range of (1.05-10.15) x 10(-6) mol L(-1), with limits of detection and quantification of 7.11 x 10(-8) mol L(-1) and 2.37 x 10(-7) mol L(-1), respectively, by linear sweep voltammetry (LSV). The method was applied to TBHQ determination in soybean biodiesel samples. The results were satisfactory in comparison with those obtained using high-performance liquid chromatography (HPLC).
de Araújo
Tatiane Alfonso
TA
Department of Chemistry, CCET, Universidade Federal de Mato Grosso do Sul, Av. Filinto Müller, 1555, Caixa postal 549, Campo Grande, MS 79070-900, Brazil.
Barbosa
Antonio Marcos Jacques
AM
Viana
Luiz Henrique
LH
Ferreira
Valdir Souza
VS
D056804:Biofuels / Q000032:analysis*; D002244:Carbon / Q000737:chemistry*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D006873:Hydroquinones / Q000032:analysis* / Q000737:chemistry; D010084:Oxidation-Reduction / Q000187:drug effects; D012015:Reference Standards; D013025:Glycine max / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*
D056804:Biofuels; D002593:Cetrimonium Compounds; D006873:Hydroquinones; D013501:Surface-Active Agents; D002244:Carbon; C018855:2-tert-butylhydroquinone; D000077286:Cetrimonium