Abstract:A liquid chromatograph-tandem mass spectrometry method was established for the eight banned Sudan dyes（Sudan Red I，Sudan Red II，Sudan Red III，Sudan Red IV，Sudan Red 7B，Sudan Red G，Sudan Blue II，Sudan Yellow）in chili products.The chili products were extracted with n-hexane，purified by alumina column，and separated by acetonitrile and 0.1%aqueous formic acid as a mobile phase，and separated by gradient elution on a C18column，and qualitatived and quantitatived by the mass spectrometer.The results showed that the linear range of 8 kinds of Sudan dyes were 2.5 ng/mL-500.0 ng/mL，and the correlation coefficient was more than the 0.999 5.The detection limit was range from 0.62 ng/mL to 6.25 ng/mL，and the lower limit of measurement was range from 2.5 ng/mL to 25.0 ng/mL，and the recovery rate was range from 92.4%to 98.6%，and the relative standard deviation were range from1.7%to 3.8%.This liquid chromatographytandem mass spectrometry （LC-MS/MS）method is suitable for rapidly screening 8 kinds of Sudan dyes in a complex matrix pepper product.