Characterization and Discrimination of Diazepam, Alprazolam, Clorazepate, Temazepam and Bromazepam with Confocal Raman Microscopy

There have been many studies about the analysis of the benzodiazepines. Most studies focused on the application of chromotography and mass spectrometer. Only several studies on the spectroscopic methods with few explanations on the peak assignment and low frequency accuracy were found. In this study, the latest confocal Raman microscope with high accuracy and extensive bands to 3500–4000 cm^–1 were employed to characterize and discriminate five typical benzodiazepine including diazepam, alprazolam, clorazepate, temazepam and bromazepam. We aimed to investigate and explain most indicative peaks of these benzodiazepines. Good discriminations were obtained among these drugs. The indicative peaks were summarized and tentatively assigned to the functional groups of the parent structure and the substituent groups. The work was necessary preparation and foundation of the surface-enhanced Raman scattering methods on fluid study in the future.