Antioxidants detection in aviation biokerosene by high-performance liquid chromatography using gold nanoparticles anchored in reduced graphene oxide

Abstract

This paper report the development of a new HPLC-pulsed amperometric detector (HPLC-PAD) for the determination of antioxidants using glass carbon electrode (GCE) modified with reduced graphene oxide (rGO) and gold nanoparticles (AuNPs). The modified electrode exhibited efficient electro-oxidation when it was applied in the analysis of three important antioxidants: N, N'-di-sec-butyl paraphenylenediamine (BPA), 2,6-Di-tert-butylphenol (TBP) and 2,6-Di-tert-butyl-4-methylphenol (BHT). The chromatographic separation was performed with an isocratic elution composed of acetonitrile/water (90:10% v/v) and 1% acetic acid. The chromatograms showed good separation of all components in periods of time less than 10 min. The developed method presented linear ranges of 5.0 × 10−6–1.3 × 10−4 mol L−1 (BPA), 2.5 × 10−6–1.0 × 10−4 mol L−1 (TBP) and 7.5 × 10−7–1.3 × 10−4 mol L−1 (BHT), and the analytical curves presented limits of detection of 1.2 × 10−7, 1.7 × 10−7 and 7.8 × 10−8 mol L−1 for BPA, TBP and BHT, respectively. The values obtained for the recovery studies conducted ranged from 97.3 ± 1.5% to 101.5 ± 2.1%. The results showed that the method is reliable, since it presented high sensitivity, precision and accuracy. The developed method was successfully applied for the determination of antioxidants in a sample of biokerosene, consisting of isoparaffins synthesized from fermented and hydroprocessed sugars. The determined concentrations were TBP 3.1 × 10−5 ± 5.5 × 10−6 mol L−1 and BHT 3.3 × 10−5 ± 2.9 × 10−6 mol L−1.