Determination of Sudan I-IV in candy using ionic liquid/anionic surfactant aqueous two-phase extraction coupled with high-performance liquid chromatography

Abstract

Ionic liquid/anionic surfactant aqueous two-phase system was developed and applied for the extraction of Sudan I-IV. High-performance liquid chromatography was applied to the determination of the analytes. The aqueous two-phase system (ATPS) was formed in the present of C4[MIM]BF4, sodium dodecyl benzene sulphonate and (NH4)2SO4. The parameters affecting the extraction efficiency, such as volume of ionic liquid, amount of sodium dodecyl benzene sulphonate, ionic strength, pH value of system, extraction time and temperature were investigated. The limits of detection for Sudan I, II, III and IV were 5.45, 4.66, 3.68, 4.20 μg kg(-1), respectively. When the present method was applied to the analysis of candy samples, the recoveries of the analytes ranged from 82.3% to 112.1% and relative standard deviations were lower than 7.41%.

Keywords: Ammonium sulphate (PubChem CID: 6097028); Candy; High-performance liquid chromatography; Ionic liquid/anionic surfactant aqueous two-phase system; SDBS (PubChem CID: 3423265); Sudan I (PubChem CID: 5858445); Sudan II (PubChem CID: 5809936); Sudan III (PubChem CID: 6789251); Sudan IV (PubChem CID: 16212227); Sudan I–IV; [C(4)MIM]BF(4) (PubChem CID: 2734178).