A new method of constant-wavelength synchronous fluorescence spectrometry for simultaneous determination of Sudan Ⅱand Sudan Ⅲ was developed with using their fluorescence phenomenon.Only one single scan is needed for effective identification and quantitative determination of the two compounds simultaneously when Δλ=60 nm is chosen.The linear ranges for Sudan Ⅱ and Sudan Ⅲ were 0—3.3 and 0—2.8 μg/mL,respectively.The detection limits for Sudan Ⅱ and Sudan Ⅲ were 14 and 11 ng/mL,respectively.By using this method,Sudan Ⅱand Ⅲ in sausage samples were determined directly with the recoveries of 83.8%—109.5%.
