Determination of delta 1-tetrahydrocannabinol in human fat biopsies from marihuana users by gas chromatography-mass spectrometry

Biomed Chromatogr. 1989 Jan;3(1):35-8. doi: 10.1002/bmc.1130030109.


A gas chromatographic-mass spectrometric (GC/MS) method for analysis of delta 1-tetrahydrocannabinol (delta 1-THC) in human fat samples is described. The fat sample, obtained from heavy marihuana users 1 week before and 4 weeks after smoking, is homogenized in hexane + 2-propanol, centrifuged, and the supernatant mixed with Lipidex 5000. The solvent is evaporated and the dried gel is packed in a glass column. delta 1-THC is eluted from the column with methanol + water + acetic acid, diluted with water and the eluent is passed through a bed of Octadecylsilane-bonded silica. After washing and drying, the retained delta 1-THC is eluted with hexane, derivatized with N-methyl-N-(t-butyl-dimethysilyl)trifluoroacetamide (MTBSTFA) and finally purified by HPLC on an Octadecyl Sl 100 column in methanol. The amount of delta 1-THC is determined by GC/MS, using selected ion monitoring, and a deuterated internal standard. The recovery of delta 1-THC is about 80%, and the concentration of delta 1-THC in the fat samples analysed ranged between 0.4 and 193 ng/g wet tissue.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adipose Tissue / analysis*
  • Biopsy
  • Chromatography, High Pressure Liquid
  • Dronabinol / analysis*
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Male
  • Marijuana Smoking / metabolism*


  • Dronabinol