[Routine detection of the THC metabolite 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid in forensic practice].

A method for the detection of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid, one of the predominant metabolites of delta 9-tetrahydrocannabinol in human urine, is presented. As screening method a homogeneous enzyme immunoassay is used (Emit dau). Positive results are confirmed by GLC/MS as alternative method. After glucuronide hydrolysis the metabolite is isolated using a C18 reversed phase column and methylated in the 1-hydroxy and 9-carboxy position. The methylated metabolite is detected by gas chromatography/mass fragmentography. This fairly rapid method seems to be useful in forensic routine analysis.