Analytical Chemistry
January 1, 1996
Jianyi Cai, Jack D. Henion
112 citations
An on-line immunoaffinity extraction-coupled column capillary liquid chromatography/tandem mass spectrometry method was developed to detect LSD and its analogs and metabolites in human urine. The system uses three columns and allows direct analysis of diluted urine without pretreatment, eliminating sample handling steps. Concentrations as low as 2.5 parts per trillion of LSD and several analogs were detected in spiked human urine, which is 20-fold lower than the previous limit of detection using solid phase extraction and liquid chromatography/tandem mass spectrometry. The method was also applied to urine specimens from LSD users.
Analytical Chemistry
July 15, 1988
Hyun Kyoon Lim, David M. Andrenyak, Paula Francom et al.
68 citations
A gas chromatography/resonance electron capture ionization mass spectrometry method was developed to quantify LSD and its metabolite N-demethyl-LSD in urine. The method achieved detection limits of 0.1 ng/mL for LSD and 0.2 ng/mL for N-demethyl-LSD, with linear calibration curves over a range of 0.5 to 20 ng/mL. The technique was applied to urine samples from human subjects administered known doses of LSD, demonstrating reliable identification and measurement of both compounds. The approach offers improved sensitivity and specificity for forensic and clinical detection of LSD use.
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.
Analytical Chemistry
November 14, 2019
Eline Pottie, Annelies Cannaert, Katleen van Uytfanghe et al.
29 citations
Classic hallucinogens, which activate the serotonin 2A receptor (5-HT2AR), represent the third largest category of new psychoactive substances. A new bioassay was developed that measures receptor activation by monitoring β-arrestin2 recruitment using a split-luciferase system. The assay determined potency and efficacy for various hallucinogens, including LSD, 5-MeO-DALT, mescaline, and several 2C compounds and their NBOMe derivatives, with EC50 values ranging from subnanomolar (NBOMes) to micromolar (mescaline) levels. When applied to plasma screening, blank samples showed pronounced receptor activation due to endogenous serotonin, confirmed by its elimination with a 5-HT2AR antagonist or MAO-A treatment, and by LC-HRMS analysis. The bioassay's main application is characterizing poorly understood serotonergic hallucinogens, as MAO-A metabolism of some compounds could bias detection in biofluids.