Ionic liquid-based supramolecular solvent microextraction for extraction of synthetic food dyes in foodstuff samples

Synthetic food dyes are a very important class of food additives. These compounds are widely used to compensate for the loss of natural colors of food, which are destroyed during processing and storage, and to provide the desired colored appearance. However, some of these substances pose a potential risk to the human health, especially if they are excessively consumed [1]. Accordingly, these food additives fall under the strict legislative control as regards their permitted usage, the enforcement of which necessitates the development of a rapid and robust analytical methodology [2]. In the present research, for the first time a new supramolecular solvent (SUPRAs) made up of aggregations of C12minBr ionic liquid was introduced. The extraction was done with micelle formation by dissolving C12minBr surfactant in appropriate water. This method, based on IL-SUPRAs-ME followed with high performance liquid chromatography with ultraviolet detection (HPLC-UV), was applied for rapid extraction and determination of three synthetic food dyes as model analytes in Gummi candy, Candy, fizzy drinks, and jelly powders samples. Effective parameters on the model analytes (i.e., pH, centrifugation time and rate, THF volume, and extraction time) were investigated and optimized by one-variable-at-a-time method. Under optimized conditions, the preconcentration factors of 68.7, 73.6, and 86.5 were obtained for Carmoisine, Ponceau 4R, and Erythrosine, respectively. The calibration curves were linear in the range of 0.2-500 μg L-1 with coefficient of determination (R2) more than 0.9970 for Every 3 analytes, detection limit (S/N=3) of 0.05-0.1 μg L−1, and The relative standard deviations (RSD %) were less than 6.5% based on three replicate measurements. Finally, the proposed method (IL-SUPRAs-ME microextraction) with Good relative recoveries in the range of 85.5–108.0% has been successfully applied for the extraction of three model analytes in different foodstuff samples.