Abstract:

Surface enhanced Raman scattering(SERS) and excitation-emission matrix(EEM) fluorescence spectroscopy were employed to determine 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 P₁(λ_ex=285 nm, λ_em=345 nm) and P₂(λ_ex=335 nm, λ_em=548 nm). Paprika red has three characteristic fluorescence peaks at P₁(λ_ex=545 nm, λ_em=580 nm), P₂(λ_ex=560 nm, λ_em=665 nm) and P₃(λ_ex=608 nm, λ_em=672 nm). The spectral information provided the references for accurate and rapid detection of Sudan Ⅰ in food.

Key words: Sudan Ⅰ, Surface enhanced Raman scattering(SERS), Excitation-emission matrix(EEM), Paprika red, Fluorescence spectrum, Raman spectrum, Food analysis