Determination of Sudan dyes in chili products by micellar electrokinetic chromatography-MS/MS using a volatile surfactant

•Determination of Sudan dyes was carried out using MEKC-MS/MS.•MEKC-MS using APFO as volatile surfactant allowed an adequate compatibility.•UAE followed by freeze-out clean-up provided negligible matrix effect.•Method was validated for three different chili products.•Limits of quantification were lower than 22 μg kg−1. A new MEKC-MS/MS method was developed for the determination of four Sudan dyes in chili products. The separation and MS detection conditions were optimized to achieve fast, efficient, selective, and sensitive determination of Sudan I, Sudan II, Sudan III, and Sudan IV dyes. The target compounds were extracted from chili samples with acetonitrile and cleaned by freeze-out. This two-step sample preparation led to excellent extraction efficiency and minimal matrix effect. The analytical performance of the method was very good, with r2 ≥ 0.9914 and limits of quantification lower than 22 μg kg−1. The precision was below 15.7%. The recovery for spiked samples ranged from 84.4 to 99.6%, with relative standard deviations less than 8.0%. For all evaluated samples, the matrix effects did not exceed ± 10%. The applicability of the proposed method was demonstrated with 20 chili products, two of which were found to contain Sudan I and IV residues.