Identification and quantitation of ibogaine and an o-demethylated metabolite in brain and biological fluids using gas chromatography-mass spectrometry.
Journal of analytical toxicology – October 01, 1995
Source: PubMed
Summary
A highly sensitive method for measuring ibogaine and its major metabolite, 12-hydroxy-ibogamine, has been developed, achieving detection limits as low as 5 ng/mL. Using gas chromatography-mass spectrometry, the quantitation demonstrated linear calibration curves between 3 to 1000 ng/mL across various biological fluids and brain tissue. This advancement allows for precise tracking of these compounds, which could enhance understanding of their effects and potential therapeutic applications. The method's reliability is underscored by strict analytical protocols ensuring accuracy in complex biological matrices.
Abstract
This report describes a sensitive method for quantitating ibogaine and a single major metabolite in biological fluids and brain tissue. We identified the metabolite as 12-hydroxy-ibogamine (12-OH-ibogamine or noribogaine) by full-scan, electron-impact gas chromatography-mass spectrometry (GC-MS). Ibogaine, 12-OH-ibogamine, and o-(methyl)-ibogaine-d3 (ibogaine-d3) internal standard were isolated by solvent extraction under basic conditions. The resulting organic extract was evaporated to dryness, and the residue was derivatized at room temperature with ethyl iodide in the presence of trimethyl anilinium hydroxide in dimethyl sulfoxide. The reaction was terminated by acidification and washed with organic solvents to remove impurities. The aqueous phase was then alkalinized and reextracted. The organic extract was concentrated and analyzed by GC-MS. Quantitation was based upon the ratios of the molecular ions at m/z 310 for ibogaine, m/z 313 for ibogaine-d3, and m/z 324 for 12-OH-ibogamine ethyl ether. The limit of detection was 5 ng/mL for both ibogaine and derivatized 12-OH-ibogamine, and limits of quantitation were between 5 and 10 ng/mL for all matrices tested. Calibration curves were linear in the range of 3-1000 ng/mL or ng/g for both analytes.