Biomedical chromatography : BMC
December 1, 2013
Steven A Barker, Jimo Borjigin, Izabela Lomnicka et al.
73 citations
A qualitative liquid chromatography-tandem mass spectrometry method was developed to simultaneously analyze three known N,N-dimethyltryptamine endogenous hallucinogens, their precursors and metabolites, as well as melatonin and its metabolic precursors. The method was characterized using artificial cerebrospinal fluid and applied to rat brain pineal gland microdialysate. It allows direct injection of 23 chemically diverse compounds plus a deuterated internal standard without dilution or extraction. The approach is simple, sensitive, specific, and uses stringent MS confirmatory criteria including exact mass measurements. For the first time, N,N-dimethyltryptamine was detected in pineal gland microdialysate from the rat.
Biomedical chromatography : BMC
March 1, 2012
Ethan H Mcilhenny, Jordi Riba, Manel J Barbanoj et al.
57 citations
A new single analytical method can directly measure 14 major alkaloid components of ayahuasca, including known and potential metabolites of N,N-dimethyltryptamine and harmala alkaloids, in human blood plasma. The method uses 96-well plate protein precipitation and filtration followed by HPLC-ion trap-ion trap-mass spectrometry with heated electrospray ionization to reduce matrix effects. It provides adequate sensitivity, specificity, and reproducibility for clinical research, expanding the list of compounds that can be monitored after ayahuasca administration while simplifying the analysis compared to previous combined techniques.
Biomedical chromatography : BMC
September 1, 2011
Ethan H Mcilhenny, Jordi Riba, Manel J Barbanoj et al.
51 citations
The primary metabolite of N,N-dimethyltryptamine (DMT) in humans after ayahuasca ingestion is the corresponding N-oxide, the first time this metabolite has been described in in vivo human studies. Very little DMT was detected in urine, despite monoamine oxidase inhibition by harmala alkaloids. The major harmala alkaloid excreted was tetrahydroharmine. A rapid, sensitive method using HPLC-electrospray ionization-selected reaction monitoring-tandem mass spectrometry was developed and applied to urine samples from three individuals administered ayahuasca, identifying and quantifying major constituents and metabolites. The protocol is suitable for toxicological and clinical research on ayahuasca.
Biomedical chromatography : BMC
September 1, 2025
Jan Thomann, Selina Kraus, Livio Erne et al.
1 citation
A new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method accurately measures ketamine and its metabolites norketamine, dehydronorketamine (DHNK), and (2R,6R)-hydroxynorketamine (HNK) in human plasma. The method uses a small sample volume, a simple protein precipitation step, and a fast run time. Linear quantification ranges were 1-1,000 ng/mL for ketamine and norketamine, 0.25-100 ng/mL for DHNK, and 2.5-1,000 ng/mL for (2R,6R)-HNK. The method showed high accuracy, precision, selectivity, and sensitivity, with consistent matrix effects and efficient extraction recovery. It was successfully applied to assess pharmacokinetics in six clinical trial participants, offering a robust approach for clinical studies, drug monitoring, and forensic investigations.