LAUSR

An analytical method based on amino acid ionic liquid aqueous two-phase extraction (ATPE) coupled with HPLC-UV detection has been developed for the determination of sunset yellow in beverages. Experimental parameters of ATPE including ionic liquids, amount of ionic liquids, pH, and temperature were investigated. Under the optimal conditions, sunset yellow within the range of 0.05–40 μg mL−1 had a good linear relationship and limit of detection was 0.021 μg mL−1. Precisions expressed as relative standard deviations (RSD) in the inter-day and intra-day analysis were all lower than ± 5%. The developed method was applied to the analysis of two commercial beverages samples, the recovery was 87.04–101.21% with the RSD of 1.8–4.6%. The proposed method is simple, sensitive, and environmentally friendly, and can be used for the determination of sunset yellow in beverages. Graphical Abstract The ATPE of sunset yellow was carried out in a 10.0-mL polypropylene centrifuge tube. A mixture of 1.0 mL of sunset yellow standard solution (10.0 μg mL−1) and 2.0 mL buffer (pH = 8.0) was placed in the tube; 0.40 g of [Ch][Ala] was added and diluted with deionized water to a final volume of 4.0 mL; K3PO4 was added to the prepared solution until aqueous two-phase was formed; the upper ionic liquid phase was collected and analyzed by HPLC The ATPE of sunset yellow was carried out in a 10.0-mL polypropylene centrifuge tube. A mixture of 1.0 mL of sunset yellow standard solution (10.0 μg mL−1) and 2.0 mL buffer (pH = 8.0) was placed in the tube; 0.40 g of [Ch][Ala] was added and diluted with deionized water to a final volume of 4.0 mL; K3PO4 was added to the prepared solution until aqueous two-phase was formed; the upper ionic liquid phase was collected and analyzed by HPLC