Abstract: A new method was established for determining Sudan Ⅰ- Ⅳ in eggs by liquid chromatography tandem mass spectrometry (LC-MS/MS). The targeted analytes in eggs were extracted by solid-phase disperse technique with a mixture of chloroform and acetonitrile (9:1,v:v). Chromatographic separation was achieved by using ZORBAX SB-C18 column. Identification and quantification were performed using multiple- reaction monitoring (MRM) and electrospray ionization in positive mode. The linearity range of Sudan Ⅰ- Ⅳ was 0.5～100ng/g, 5.0～100ng/g，1.0～100ng/g and 2.0～100ng/g, respectively, and r>0.99. The recovery of determination of Sudan residues in eggs was between 87.3 %-113 % with RSD less than 9.1 %. The detection limit of this method was 0.1μg/kg (Ⅰ), 2.0μg/kg (II), 0.2μg/kg (III) and 0.4μg/kg (Ⅳ), respectively, which could meet the requirement of the Sudan residues monitoring both abroad and home.

Key words: Eggs, Liquid Chromatography tandem mass Spectrometry (LC-MS/MS), Solid-phase disperse technique , Sudan