Studies on the Identification of Methamphetamine hydrochloride by Infrared Absorption Spectra Method

The infrared spectrum of methamphetamine hydrochloride by diffuse reflectance spectroscopy was compared with that by transmission spectroscopy. The former spectrum remained unchanged after preparation of a KBr disc, while the latter changed with the elapse of time.   The liquid sample drop method which is frequently used in diffuse reflectance spectroscopy simplified sample preparation, and purification in the measurement of the infrared spectrum of methamphetamine hydrochloride.   Consequently, reflectance spectroscopic measurement by the liquid sample drop method using an auto-sample-changer made it possible to obtain the infrared spectra of many samples easily and quickly.