A new sample-preparation method uses eucalyptus essential oil, instead of conventional organic solvents, to extract four ayahuasca-related compounds (DMT, harmine, harmaline, and tetrahydroharmine) from human plasma. After optimizing the procedure with factorial experiments, the method was validated and applied to 13 real plasma samples. Detection limits were ≤1.0 ng/mL, and the method was linear up to 150 ng/mL. Recovery averaged 50%, and matrix effects showed ion suppression of 56–83%. The approach is simple, fast, and environmentally friendly, offering a green alternative for forensic and clinical drug analysis.
A liquid chromatography–tandem mass spectrometry method was developed and validated to detect and quantify six 4-position ring-substituted tryptamines in plasma, including psilocybin, psilacetin, 4-Pro-DMT, and their metabolites psilocin and 4-HO-DPT. The method showed linearity from 0.5 to 100 ng/mL for most analytes (psilocybin from 5 to 100 ng/mL), with acceptable bias and imprecision. Matrix effects were minimal except for ion enhancement of psilocin and psilocybin. Extraction efficiency was about 50%. Applied to plasma from male rats given psilacetin, psilacetin was not detected, and psilocin concentrations ranged up to 32.7 ng/mL. The method provides a robust tool for future research and clinical applications.