Quantitative Determination of LSD and a Major Metabolite, 2-Oxo-3-Hydroxy-LSD, in Human Urine by Solid-Phase Extraction and Gas Chromatography-Tandem Mass Spectrometry
Journal of Analytical Toxicology September 1, 1999 Scott Reuschel, Shaundel Percey, S. Liu et al. 38 citations
A new assay can detect lysergic acid diethylamide (LSD) and its major metabolite, 2-oxo-3-hydroxy-LSD, in human urine at concentrations as low as 10 pg/mL. In most LSD-positive urine samples, the metabolite is present at higher concentrations than LSD and remains detectable longer after ingestion. The method uses solid-phase extraction, trimethylsilylation, and gas chromatography-tandem mass spectrometry with selected reaction monitoring. Linear calibration curves were obtained from 10 pg/mL to 5000 pg/mL. Reanalysis of 49 previously positive urine samples showed an average LSD concentration of 357 pg/mL and an average metabolite concentration of 3470 pg/mL. Clinical dosing experiments support that analyzing for the metabolite extends the detection window for identifying LSD use.