Rapid ion pair-based surfactant-assisted liquid-liquid microextraction with solidification of floating organic drop for simultaneous spectrophotometric determination of selected anionic dyes in food samples.

Ion pair-based surfactant-assisted liquid-liquid microextraction with solidification of floating organic drops has been developed to extract Allura red (AR), tartrazine (TAR), and fast green (FG) prior to spectrophotometric determination. Cetyltrimethylammonium bromide (CTAB) was employed as ion-pairing agent to enhance the hydrophobic behavior of anionic dyes. 1-undecanol and ethanol were used as the extraction and dispersion solvents, respectively. The dyes were quantitatively extracted in the presence of KCl (0.15 mol L) at pH 4.0. The method exhibits wide linearity (15.0-1500.0 μg L for AR, 35.0-2000.0 μg L for TAR, and 3.0-1200.0 μg L for FG) with preconcentration factors of 19.6, 20.1, and 19.9, respectively. The detection limit was 3.7. 9.5, and 0.83 μg L for AR, TAR, and FG, respectively. The relative standard deviation did not exceed 2.1 %. The procedure was applied for the determination of these dyes in food samples.