Key points are not available for this paper at this time.
A high performance liquid chromatographic (HPLC) procedure was developed for the analysis of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic 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 C8 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-delta 9-tetrahydrocannabinol-9-carboxylic acid was 25 ng/mL.
ElSohly et al. (Tue,) studied this question.