Quantification of 9-carboxy-11-nor-delta 9-tetrahydrocannabinol in urine using brominated 9-carboxy-11-nor-delta 9-tetrahydrocannabinol as the internal standard and high-performance liquid chromatography with electrochemical detection.
A method was developed for quantitating 9-carboxy-11-nor-delta 9-tetrahydrocannabinol in human urine as part of the process for validating an automated enzyme immunoassay for marijuana metabolites. Sample cleanup was accomplished using a mixed-mode solid-phase extraction. 9-Carboxy-11-nor-delta 9-tetrahydrocannabinol and the internal standard, brominated 9-carboxy-11-nor-delta 9-tetrahydrocannabinol, were quantified using high-performance liquid chromatography with electrochemical detection (+ 0.85 V). The linear range for this method is 0.012-0.20 microgram/mL. No interference was seen for 22 drugs and metabolites. The pooled relative standard deviation is 4.1% (n = 27) for the quality control samples. This method was compared to gas chromatography with mass spectrometry by linear regression analysis. The slope of the line is 1.00 +/- 0.05 (standard error), the intercept is approximately zero, the coefficient of determination is 0.994, and the standard error of the estimate is 0.006 microgram/mL.
Fisher
D H
DH
Department of Medical Laboratory Science, Northeastern University, Boston, MA 02115, USA.
Broudy
M I
MI
Fisher
L M
LM
D001966:Bromine / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D013759:Dronabinol / Q000737:chemistry / Q000652:urine*; D004563:Electrochemistry; D006213:Hallucinogens / Q000737:chemistry / Q000652:urine*; D006801:Humans; D016014:Linear Models; D011786:Quality Control; D012015:Reference Standards
D006213:Hallucinogens; D013759:Dronabinol; D001966:Bromine