Comparative studies by IR, Raman, and surface-enhanced Raman spectroscopy of azodicarbonamide, biurea and semicarbazide hydrochloride.

Highlights: [•] IR, Raman and SERS methods have been studied on azodicarbonamide, biurea, and semicarbazide hydrochloride. [•] The molecular structure and assignment of these three molecules have been studied by DFT calculations. [•] The limit of detection of this method being as low as 10μg/mL (less than the standard regulation). [ABSTRACT FROM AUTHOR]