SERS and EEM Fluorescence Spectral Distinction of Sudan I and Paprika Red in Food

Surface enhanced Raman scattering(SERS) and excitation-emission matrix (EEM) fluorescence spectroscopy were employed to deteimine an illegal food additive(Sudan I) and legitimate food additive(paprika red). SERS spectra show that the torsion vibration modes of Sudan I is obviously enhanced in lower frequency range while the peaks of paprika red at 1521 and 1158 cm(-1) are great enhanced as well. EEM fluorescence spectra show that Sudan I has two obvious characteristic fluorescence peaks at P-1 (lambda(ex) =285 nm, lambda(em) =345 nm) and P-2 (lambda(ex) =335 nm, lambda(em) =548 nm). Paprika red has three characteristic fluorescence peaks at P-1(lambda(ex) =545 nm, lambda(em) =580 nm), P-2(lambda(ex) =560 nm, lambda(em) =665 nm) and P-3(lambda(ex) =608 nm, lambda(em) =672 nm). The spectral information provided the references for accurate and rapid detection of Sudan I in food.