Essential oil-based dispersive liquid-liquid microextraction for the determination of N,N-dimethyltryptamine and β-carbolines in human plasma A novel solvent-free alternative.
The present study describes the development of a novel solvent-free vortex-assisted dispersive liquid-liquid microextraction alternative based on a natural essential oil as extracting solvent (VA-EO-DLLME) for the determination of N,N-dimethyltryptamine (DMT), harmine (HRM), harmaline (HRL) and tetrahydroarmine (THH) (compounds found in the ayahuasca tea, a psychedelic plant preparation) in human plasma. After optimization through full factorial and Box-Behnken experimental designs, this VA-EO-DLLME followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MSMS) was completely validated and applied to authentic plasma specimens. Sample preparation consisted in the addition of 60 mg of NaCl, 100 μL of borate buffer and 100 μL of Eucalyptus globulus essential oil to a 200 μL aliquot of human plasma. After 30 s of vortex agitation followed by 5 min of centrifugation (10,000 rpm), 80 μL of the oil supernatant was dried and resuspended in mobile phase prior to injection into the UHPLC-MSMS system. Once optimized, the validated method yielded LoDs ≤1.0 ng mL