Testing human hair after magic mushrooms abuse by LC-MS/MS: Pitfalls and limitations

Abstract Although it has been published during the last 15 years that hallucinogens derived from new psychoactive substances are increasingly abused, the old psychedelic agents are still used. Among these vegetal compounds, magic mushrooms are frequently mentioned. The major ingredient of the Psilocybe species is psilocybin, which is rapidly converted into psilocin in the human body. Therefore, psilocin represents the key target to document magic mushrooms abuse. The aim of the present work was to develop a specific method to identify psilocin in human hair by LC-MS/MS and review potential pitfalls. The method involves incubation of 10 mg of cut hair in 1 mL of acid methanol in presence of psilocin-d10 for 2 hours at 4 °C. The chromatographic separation was performed using a reverse phase column HSS C18 with a gradient elution of 8 min. Linearity was verified from 1 to 200 pg/mg (r2 = 0.9994), after spiking blank hair with the corresponding amounts of psilocin. The limit of detection was estimated at 0.4 pg/mg. The precision was lower than 20 % and there was no interference with any extractable material present in hair. Psilocin was identified in the hair of a repetitive magic mushrooms consumer at 2.5 pg/mg (segment 0-1 cm), 4.4 pg/mg (segment 1-2 cm) and 5.4 pg/mg (segment 2-3 cm). Cold conditions during hair preparation and protection from the light were found mandatory to avoid psilocin degradation.