Determination of lysergic acid diethylamide (LSD), iso-LSD, and N-demethyl-LSD in body fluids by gas chromatography/tandem mass spectrometry
Analytical Chemistry July 15, 1992 Chad C. Nelson, Rodger L. Foltz 64 citations
Capillary gas chromatography/tandem mass spectrometry (GC/MS/MS) methods can detect and quantify LSD, iso-LSD, and N-demethyl-LSD in urine or blood at low-pg/mL concentrations. Derivatization, sample introduction, and ionization techniques were evaluated for efficiency and specificity. Fragmentation pathways from collision-induced dissociation show principal losses from the amide and piperidine-ring moieties. Positive-ion ammonia chemical ionization with MS/MS analysis of trimethylsilyl derivatives provides high specificity for identifying these compounds. Negative-ion chemical ionization with GC/MS/MS of the trifluoroacetyl derivative is suited for trace-level identification of N-demethyl-LSD, a metabolite.