Development of a facile sensor for the determination of Brilliant Blue FCF in beverages

<div><p>A facile method was developed for the detection of Brilliant Blue FCF (BB FCF) (E133), a synthetic soluble colorant in common beverages. The method is based on a new composite of multi-walled carbon nanotube (MWCNT)-graphite oxide (GO)-room temperature ionic liquids (MWCNT/GO-RTIL) of 1-butyl-3-methylimidazolium hexafluorophosphate with high dispersibility and strong conductivity. Differential pulse stripping voltammetry (DPSV) and the MWCNT/GO-RTIL composite-modified glassy carbon electrode (GCE) were used to determine the BB FCF in this work. Under the optimum experimental conditions, the oxidation current of BB FCF was proportional to its concentration in two linear ranges, from 6.34 μg kg<sup>−1</sup> to 7.93 × 10<sup>2</sup> μg kg<sup>−1</sup> and 7.93 × 10<sup>2</sup> μg kg<sup>−1</sup> to 7.93 × 10<sup>3</sup> μg kg<sup>−1</sup>.</p><p>The detection limit was down to 3.01 μg kg<sup>−1</sup> at signal-to-noise ratio of 3. Also, this method has been successfully applied in the determination of BB FCF in common beverage samples, including RIO cocktail, Bacardi Breezer and Reinnbow rum dinks. The assay results of BB FCF in drink samples obtained by the proposed method were in a good agreement with the reference values detected by high performance liquid chromatography (HPLC). The proposed method provided a useful tool for the assay of BB FCF in drink samples.</p></div>