A Method for Identification of Lysergic Acid Diethylamide (LSD) Using a Microscope Sampling Device with Fourier Transform Infrared (FT/IR) Spectroscopy

A method for identifying lysergic acid diethylamide (LSD) in seized microgram quantities produces small pure crystals suitable for analysis with a microscope sampling device and Fourier transform infrared (FT/IR) spectrometer. The technique yields excellent spectra from samples containing less than 50 µg of LSD and can distinguish LSD from iso-LSD and lysergic acid N-methylpropylamide (LAMPA). The approach combines preparative thin-layer chromatography with wick evaporation, an older technique for separating soluble components from high-solid mixtures without filtration.

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Abstract

Abstract The identification of lysergic acid diethylamide (LSD) has posed an analytical challenge for forensic science laboratories. In those cases in which a few doses are seized, only microgram quantities are available, often in forms which make isolation of the miniscule amount of LSD difficult. A method is described which yields small crystals of pure LSD in a form well-suited for analysis using a microscope sampling device with a Fourier transform infrared (FT/IR) spectrometer. These crystals produce excellent spectra from samples containing less than 50 µg of LSD. Distinguishing between LSD, iso-LSD, and lysergic acid N-methylpropylamide (LAMPA) poses no problem with the spectra obtained. This scheme combines preparative thin-layer chromatography (TLC) followed by wick evaporation, an old but not well-known technique for separating soluble components from high-solid mixtures without filtration.