The detection of psilocin in human urine

Pharmacokinetic studies of psilocybin in humans have shown the rapid dephos phorylation of psilocybin to psilocin with further conversion to 4-hydroxy- tryptophole (4HT) and 4-hydroxyindole-3-acetic acid (4HIAA) in plasma. Our study shows that psilocin also undergoes conjugation and can be found in th e urine as the psilocin-glucuronide conjugate. Recoveries after enzymatic h ydrolysis of the urine with beta -glucuronidase (Helix Pomatia or E. Coli) when compared to non-hydrolyzed urine confirmed the presence of the glucuro nide. Detection of psilocin From hydrolyzed and extracted samples was optim ized for GC/MS by derivatization with MSTFA. The method developed allows fo r the detection of psilocin in urine with a limit of quantitation of 10 ng/ mL, based on 5 mt of spiked urine. Using this method, our laboratory has co nfirmed the presence of psilocin in 6 out of 8 urine samples, with concentr ations ranging from 10 ng/mL to greater than 200 ng/mL. Before implementati on of the hydrolysis and derivatization steps, our limit of detection was 2 00 ng/mL, based on spiked urine standards. No case samples were positive wi thout hydrolysis and derivatization.