Liquid chromatography-electrospray ionization mass spectrometry for the detection of lysergide and a major metabolite, 2-oxo-3-hydroxy-LSD, in urine and blood.

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Abstract
A method is presented for the quantitative measurement of lysergide (LSD) and its metabolite 2-oxo-3-hydroxy-LSD (O-H-LSD) in urine and blood. O-H-LSD has been reported to have urinary concentrations many times higher than LSD. Measuring its presence in urine would significantly extend the detection lime for confirming LSD abuse. A single-step liquid-liquid extraction was performed on 5-mL urine samples prior to separation by gradient liquid chromatography (LC). Electrospray ionization was used to produce the positively charged ions of O-H-LSD, 2-oxo-3-hydroxy-LAMPA (O-H-LAMPA, internal standard), LSD, and iso-LSD. Varying the orifice voltage in the intermediate-pressure region of the source generated the fragmentation necessary to produce qualifying ions. Selected ion monitoring allowed detection limits of 400 pg/mL and 100 pg/mL for O-H-/SD and LSD, respectively. The method was linear for O-H-LSD from 400 to 8000 pg/mL and for LSD from 100 to 6000 pg/mL. LSD-positive samples (n = 9) analyzed by the liquid chromatography-mass spectrometry method were found to contain mean concentrations of 6378 pg/mL O-H-LSD (332–21371 pg/mL) and 844 pg/mL LSD (177–2456 pg/mL). O-H-LSD urinary concentrations were between 0.9 and 19.8 times higher than LSD (mean = 10.2). Whole-blood samples were also analyzed following additional sample cleanup. LSD was measured in the blood samples, but no O-H-LSD was detected. Enzymatic hydrolysis was carried out on LSD-positive samples (n = 6) to evaluate the existence of conjugated O-H-LSD. β-Glucuronidase from Helix pomatia was incubated with urine samples at 37°C, pH 5.2 for 24 h. At an enzymatic activity of approximately 4000 units per milliliter of urine, no significant (p = 0.05) difference was seen between hydrolyzed and nonhydrolyzed samples suggesting an absence of O-H-LSD-glucuronic acid conjugation.

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