A dispersive liquid-liquid microextraction method for the determination of ayahuasca alkaloids (N,N-dimethyltryptamine and β-carbolines) in human hair.

A greener analytical method using dispersive liquid-liquid microextraction and LC-MS/MS was developed to measure N,N-dimethyltryptamine (DMT) and three β-carbolines (harmine, harmaline, tetrahydroharmine) in human hair. The method was sensitive, with limits of quantification from 3 to 8 pg/mg, and linear up to 1000 pg/mg. Recovery was low (36-58%), but selectivity showed no interference. Applied to six real samples, DMT concentrations ranged from 21.5 to 204.4 pg/mg, while β-carbolines were generally higher, with harmine reaching over 1000 pg/mg. The method uses less organic solvent than conventional hair extraction, advancing green analytical toxicology for psychoactive alkaloids.

Study at a glance

Abstract

Ayahuasca, a traditional Amazonian hallucinogenic plant brew once used in healing rituals, is now globally popular, raising safety concerns outside ceremonial contexts. Its compounds, alkaloids, are stimulating scientific interest for their potential antidepressant and anxiolytic effects. In this study, we employed a more sustainable analytical extraction method for the determination of N,N-dimethyltryptamine (DMT), harmine (HRN), harmaline (HRL), and tetrahydroharmine (THH) in human hair using LC-MS/MS. We incorporating dispersive liquid-liquid microextraction (DLLME) in line with the principles of Green Analytical Toxicology (GAT). The limit of quantification (LoQ) was 3 pg/mg for HRN and 8 pg/mg for DMT, HRL, and THH. The method was linear in the LoQ range up to 1000 pg/mg (r2 ≥ 0.99). Intra- and inter-day precision and accuracy met the acceptance criteria at three quality control (QC) levels. Matrix effect (EM) showed both ionization enhancement and suppression, values ranged from 80.20 % (DMT, CQB) to 121.85 % (HRL, CQA). Recovery (RE) was low with recovery values ranging from 36.28 % to 57.91 %. Selectivity studies revealed no interference. Application to six authentic samples confirmed the viability of the method. Measured concentrations were DMT (21.5-204.4 pg/mg) and β-carbolines: THH (55.5 - >LOQ pg/mg); HRL (42.0-988.2 pg/mg) and HRN (163.0 - >LOQ pg/mg). Notably, β-carbolines were generally detected at higher concentrations than DMT. The proposed method uses smaller amounts of organic solvents compared to conventional hair extraction methods, representing a significant methodological advancement in the analysis of psychoactive alkaloids in biological matrices.