|SOFT - TIAFT 1998||Poster Session 4||Friday October 9, 1998|
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|
Scott A. Reuschel, Rodger L. Foltz, Shaundel E. Percey, Sherry Liu, and Don M. Eades
Northwest Bioanalytical, A Division of NWT, Inc., 1121 East 3900 South, Salt Lake City, Utah 84124, USA
|LSD continues to be a widely used drug of abuse. One reason for the continued use may be the difficulty in detecting LSD use by urine analysis. We have developed a method for the confirmation of LSD use which not only quantifies the parent LSD, but also quantifies a major human metabolite, 2-oxo-3-hydroxy-LSD, which is generally present in human urine at much higher concentrations and for longer periods of time than the parent LSD. Sample preparation is achieved by solid-phase extraction using Certify Bond Elut extraction cartridges. Confirmatory identification is accomplished by the trimethylsilyl derivatization of LSD and 2-oxo-3-hydroxy-LSD followed by GC/MS/MS analysis with positive ion chemical ionization detection. LAMPA and 2-oxo-3-hydroxy-LAMPA are used as internal standards. With selected reaction monitoring, both compounds give linear calibration curves from 10 pg/mL to 5000 pg/mL.
Thirty-nine human urine samples from a forensic workplace drug testing program which had previously been confirmed to contain LSD were reanalyzed by this method. Upon reanalysis, the thirty-nine samples showed an average LSD concentration of 319 pg/mL with an average 2-oxo-3-hydroxy-LSD concentration of 4083 pg/mL, (approximately 12 times higher than the average LSD concentration). Additional experiments utilizing clinical samples in which subjects were dosed with LSD indicated that while LSD concentrations typically fall below current confirmation limits (and Department of Defense approved cutoff levels) after 12-24 hours post-administration, 2-oxo-3-hydroxy-LSD concentrations were detectable up to 96 hours post-administration.
This method provides a more effective method for the detection of LSD use by the quantitation of the LSD human metabolite, 2-oxo-3-hydroxy-LSD, which is commonly present at higher concentrations and provides a longer window of detection than LSD.