Development of a method for spectrophotomectric determination of brilliant blue FCF used as a synthetic colorant in daily life consumed drinks

In this study, a simple, sensitive, and rapid method called green hydrophobic deep eutectic solvent-based liquid-liquid microextraction was developed to extract Brilliant Blue FCF dye from beverages. This method utilizes hydrophobic DES obtained by forming tetrabutylammonium bromide and 1-octanol in a 1:5 ratio as green extraction solvent. The transition of Brilliant Blue FCF to the DES phase occurred on its own, without the need for any reagents such as added salt or tetrahydrofuran. To get the best extraction efficiency, several crucial factors were tried, including species, DES volume and molar ratio, solution pH, ultrasonication, and centrifugation time. Under optimum conditions, extraction recoveries were achieved in the range of 95.1-101.3% with the method developed for Brilliant Blue FCF. The detection and determination limits were observed to be 4.1 μg L-1 and 12.1 μg L-1, respectively. In addition, the relative standard deviation values for the method's accuracy were found to be 2.23% and 3.48% within and between days, respectively. This study shows that DES applications can be carried out without the use of emulsifiers and dispersants by prioritizing the use of hydrophobic DES compounds as environmentally friendly and green extraction solvents in food samples.