Raman Spectroscopic Differences between Ephedrine and Pseudoephedrine.

Ephedrine (EPH) and pseudoephedrine (PSE) were studied by micro-Raman spectroscopy and UV resonance Raman spectroscopy excited at 785 and 360 nm, respectively. Raman bands at approximately 245 and 410 cm-1 for ephedrine have apparent differences from the same bands at approximately 215, 265, 350, 450, and 555 cm-1 for pseudoephedrine, and these differences can be applied to distinguish between EPH and PSE. Additionally, density functional theory was used for the Raman calculations to obtain results identical to the experimental spectra. This work is expected to expand the applications of Raman spectroscopy in forensic science.