WEBDrug Monitoring, Marijuana Metabolite, Quantitative, Urine - 11-Nor-9-Carboxy-delta 9 -THC (THCCOOH) is commonly accepted as the primary urinary metabolite in man. Detection of this metabolite is indicative of exposure to marijuana. The test is a definitive assay using a specific and sensitive liquid chromatography mass spectroscopy (LC/MS/MS) methodology.