A Core-Shell Column Approach to Fast Determination of Synthetic Dyes in Foodstuffs by High-Performance Liquid Chromatography

A novel and fast analytical method for determination of eight synthetic food dyes (Tartrazine, Amaranth, Indigo carmine, Ponceau 4R, Sunset yellow, Brilliant black BN, Allura red, and Acid red 1) in foods was developed and validated using high-performance liquid chromatography coupled to photodiode array detection. Chromatographic system was equipped with C18 core-shell column, using 100 mM ammonium acetate buffer (pH 7) and acetonitrile mobile phase in the gradient elution mode. Parameters affecting separation, such as mobile phase composition, pH, buffer concentration, column oven temperature, and flow rate, were assessed and optimized by employing a step-by-step strategy. Using a core-shell column, the separation of eight synthetic dyes was achieved in 5.5 min with a run-to-run analysis time of 8 min. Under optimum conditions, developed method was linear in the range of 0.25–10 μg/mL. The relative standard deviation at three concentration levels (1, 5, and 9 μg/mL) was less than 3% with accuracy in the range of 97.95 to 102.89%. The method was applied to the determination of synthetic dyes in seven different foods. The results of this study demonstrate that the use of core-shell column can be considered as a desirable alternative for the routine monitoring analysis of synthetic dyes.