CONFIRMATION TESTING OF 11-NOR-DELTA-9-TETRAHYDROCANNABINOL-9-CARBOXYLIC ACID IN URINE WITH MICELLAR ELECTROKINETIC CAPILLARY CHROMATOGRAPHY

The major urinary metabolite of the most commonly abused psychotropic drug, DELTA9-tetrahydrocannabinol, is 11-nor-DELTA9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH). With basic hydrolysis, extraction and concentration, this compound can easily be determined using micellar electrokinetic capillary chromatography with on-column multi-wavelength detection. After solid-phase extraction of 5 ml of urine, drug concentrations down to about 10 ng/ml can be unambiguously monitored. Peak assignement is achieved through comparison of the retention time and absorption spectrum of the eluting THC-COOH peak with those of computer-stored model runs. The effectiveness of the approach is demonstrated with data obtained from urine samples from different patients which tested positively for cannabinoids using a fluorescence polarization immunoassay.