Raman Spectra of Sudan Red Dyes and the Fluorescence Background Removal

Sudan red dyes, as illegal food additives, can induce carcinoma of bladder. It is important to find out a method to provide an easy, precise and sensitive detection. The aim of our study is to obtain the Raman feature frequency excursion of SudanI, IIand III, and draw clear Raman spectra. We used the Raman Systems R-3000 spectrometer to detect the solid SudanI(97.5%), II(analytical pure) and III(97.0%). Furthermore, we removed the fluorescence background via curve fitting. The Raman spectrograms show that wave peak of Sudan Iappears on 458, 718, 990, 1091, 1163, 1224, 1335, 1385, 1450, 1492, 1593cm-1, peak of Sudan IIappears on 454, 708, 982, 1225, 1378, 1492, 1602cm-1, and peak of Sudan III appears on 456, 716, 981, 1127, 1227, 1383, 1415, 1437, 1492, 1591cm-1. In conclusion, Raman spectroscopy is an ideal measure to provide qualitative analysis of Sudan red dyes. And the results can help us to evaluate the food quality and safety.