The detection of psilocin in human urine.
Pharmacokinetic studies of psilocybin in humans have shown the rapid dephosphorylation 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 the urine as the psilocin-glucuronide conjugate. Recoveries after enzymatic hydrolysis of the urine with beta-glucuronidase (Helix Pomatia or E. Coli) when compared to non-hydrolyzed urine confirmed the presence of the glucuronide. Detection of psilocin from hydrolyzed and extracted samples was optimized for GC/MS by derivatization with MSTFA. The method developed allows for the detection of psilocin in urine with a limit of quantitation of 10 ng/mL, based on 5 mL of spiked urine. Using this method, our laboratory has confirmed the presence of psilocin in 6 out of 8 urine samples, with concentrations ranging from 10 ng/mL to greater than 200 ng/mL. Before implementation of the hydrolysis and derivatization steps, our limit of detection was 200 ng/mL, based on spiked urine standards. No case samples were positive without hydrolysis and derivatization.
Grieshaber
A F
AF
Division of Forensic Toxicology, Office of the Armed Forces Medical Examiner, Armed Forces Institute of Pathology, Rockville, MD 20850, USA. grieshaber@afip.osd.mil
Moore
K A
KA
Levine
B
B
D005554:Forensic Medicine / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D006213:Hallucinogens / Q000652:urine*; D006801:Humans; D011562:Psilocybin / Q000031:analogs & derivatives* / Q000652:urine*; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods
D006213:Hallucinogens; D011562:Psilocybin; C009105:psilocin