Sensitive Analysis of LSD by Microscope/FTIR Using Pinpoint Condensation Technique

Abstract

  The pinpoint condensation technique using perfluorated polymer film was applied to the identification of lysergic acid diethylamide (LSD). Rapid solvent elimination for condensation of LSD into a small single residual at room temperature was performed by solvent evaporation on perfluorated polymer film, and the residual was measured by the microscope/FTIR technique. This sample condensation method provided high sensitivity for IR analysis. The detection limit was 2ng. When interfering substances did not exist in the extracted solution from blotter paper of LSD, the extract was able to be measuered simply and rapidly by microscope/FTIR technique. If isolation by preparative TLC was needed, the best elute was ethyl acetate or isopropanol which did not elute interfering substances from TLC plate into the eluent. More than 5 μg of LSD would be detectable by this technique after preparative TLC. We were able to identify LSD by this technique with preparative TLC from blotter paper containing more than 10 μg of it. This technique was useful to identify LSD sensitively from forensic samples.