Analysis of the Major Metabolite of 9-Tetrahydrocannabinol in Urine II. A HPLC Procedure

Abstract
A high performance liquid chromatographic (HPLC) procedure was developed for the analysis of 11-nor-Δ9-tetrahydrocannabinol-9-carboxyUc acid in urine. Hydrolyzed urine samples were cleaned up using Bond-Elut® columns. 11-Nor-cannabinol-9-carboxylic acid was used as internal standard. The analysis was carried out using a Ca reversed-phase column with acetonitrile:50 mM phosphoric acid (65:35) as the solvent. Detection was done by ultraviolet detector at 214 nm. The minimum detectable level of 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid was 25 ng/mL.