偶氮甲酰胺，联二脲，盐酸氨基脲的红外、拉曼、表面增强拉曼光谱的研究

zodicarbonamide is widely applied in the food industry as a new flour gluten fortifier in China, Canada, United States and some other countries, whose metabolites of biurea and semicarbazide hydrochloride are reaction products during baking. In this study, IR, Raman, and surface-enhanced Raman scattering (SERS) spectra of azodicarbonamide, biurea, and semicarbazide hydrochloride have been recorded, and the molecular geometries and vibrational bands have been assigned on the basis of density functional theory (DFT) calculations. Calculated Raman spectra were in good agreement with experimental Raman spectra. The SERS method coupled with active gold substrates has also been applied for detection of these three chemicals with nitric acid as solvent, with the limit of detection of this method being as low as 10 μg/mL. These results showed that azodicarbonamide and its metabolites could be detected by the SERS technique, so that this method might be applied as a powerful tool for the rapid detection on these species derived from agents added to flour.