Tetrahydrocannabinol-9-carboxylic acid

The tetrahydrocannabinol carboxylic acid was extracted from the urine by means of a solid state extraction cartridge packed with a Cl 8 reverse phase (octyldecyldimethyl chains). As the urine sample was used direct, and contained no added solvent, the materials of interest were irreversibly adsorbed on the reverse phase solely by dispersive interactions. 

Tetrahydrocannabinol carboxylic acid, a component of hashish. Angew Chem Int Ed Engl 1965 4 872. 

There are a number of reasons why derivatization of samples is necessary. First, the hydroxide and carboxylic moieties may form hydrogen-bonds in the gas phase, thus resulting in poor chromatography. Secondly, the compounds may sorb onto the chromatographic system, resulting in poor chromatography performance, peak shape, and in the case of very low concentrations, non-detection of the analytes. Furthermore, it is known that -tetrahydrocannabinol carboxylic acid thermally decarboxylates at temperatures above 110-120° C, and converts into A -tetrahydrocannabinol. While in some laboratories this is assumed to be quantitative, this may not always be the case. Derivatization will allow determination of both the A -tetrahydrocannabinol and its carboxylic acid. In addition, in the case of very low concentrations of analytes, derivatization will improve the limits of determination and quantification. 

Tetrahydrocannabinol (= THC)-11-carboxylic acid 290 Tetrahydrocortiso 221 Tetrahydrocortisone 221 Tetrahydrosteroids 222 Tetrazolium salts, reduction 61 Thalidomide 45 -, hydrolysis products 45 Thiabendazole 307, 308 Thiamine 235, 236, 397 Thickening agents 179 Thin-layer chromatography, advantage 5 -, numbers of publications per year 6 Thiobarbiturates 45,66 Thiocarbamide derivatives 322 Thiocarbamides, N -ary I-N -benzenesulfo-nyl- 248,249 Thiochrome 395... 

Breindahl T, Andreasen K. 1999. Determination of 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid in urine using high-performance liquid chromatography and electrospray ionization mass spectrometry. J Chromatogr B Biomed Sci Appl 732 155. 

Tai SS, Welch MJ. 2000. Determination of ll-nor-delta9-tetrahydrocannabinol-9-carboxylic acid in a urine-based standard reference material by isotope-dilution liquid chromatography-mass spectrometry with electrospray ionization. J Anal Toxicol 24 385. 

Fernandez MDR, Wille SMR, Samyn N, Wood M, Lopez-Rivadulla M, De Boeck G (2009) On-line solid-phase extraction combined with liquid chromatography-tandem mass spectrometry for high throughput analysis of 1 l-nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid in urine. J Chromatogr B 877(22) 2153—2157. doi 10.1016/j.jchromb.2009.04.047... 

Quantitation of a 9-Tetrahydrocannabinol and 11-Nor-a 9-tetrahydrocannabinol-9-carboxylic Acid in Body Fluids by GC/CI-MS... 

HPLC Analyses of A9-Tetrahydrocannabinol and ll-Nor-A9-tetrahydrocannabinol-9-carboxylic Acid in Human Plasma... 

Metabolism of I in humans has been studied by several groups (5-8) with findings that 11-hydroxy A9 -tetrahydrocannabinol (V) and ll-nor-A9-tetrahydrocanni-binol-9-carboxylic acid (VI) are the principal metabolites. ... 

Elsohly, M. A., Jones, A. B., Elsohly, H. N., and Stanford, D. F., Analysis of the major metabolite of delta-9-tetrahydrocannabinol in urine. VI. Specificity of the assay with respect to indole carboxylic acids, /. Anal. Toxicol., 9, 190, 1985. 

Cannabis is extensively metabolized in the human to 11 hydroxy- and 8 3 hydroxy-A9-tetrahydrocannabinol (11 OH and SP OH-THC) and finally to 11 nor-A9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), which is conjugated with glucuronic acid to a variable extent. 

Kippenberger, D., Hayes, E., Schultz, H., Gordon, A. M., and Baumgartner, W., The detection and quantitation of ll-nor-A9-tetrahydrocannabinol-9-carboxylic acid in hair using tandem mass spectrometry, presented at TIAFT/SOFT Joint Congress, Tampa, October 31 to November 4,1994, paper 52. 

Another MEKC separation (75 mM SDS, phosphate-borate buffer, pH 9.1) was reported for die determination of ll-nor-A-9-tetrahydrocannabinol-9-carboxylic acid, the major metabolite of A-9-tetrahydrocannabinol present in urine (Wemly and Thormann, 1992a). Sample treatment included basic hydrolysis of urine (5 mL), solid phase extraction, and concentration. The resulting sensitivity was 10 to 30 ng/mL (i.e., comparable to the cutoffs of immunoassays). Again, detection was by on-line recording of peak spectra, by means erf fast-scanning UV detector. 

Cannabis provides a similar example. The detection of A -tetrahydrocannabinol in blood indicates very recent use of the drug (within 8 hours). Further, the concentrations of ll-nor-A -tetrahydrocannabinol-9-carboxylic acid and its glucuronide increase with time, the ratio of the acid to A -tetrahydrocanna-binol increasing to over 50 after about 3 hours. Concentration ratios of drug metabolite or metabolite metabolite of the above type often provide better estimates of the time since ingestion than the individual blood concentrations, especially when the time involved is relatively long. Unless a drug is very rapidly metabolised (as is the case... 

GC-MS, Gas chromatography-mass spectrometry HHS, Department of Health and Human Services DOT, Department of Transportation DOD, Department of Defense MDA, methylenedioxyamphetamine MDAM, methylenedioxymethamphetamine MDEA, methylenedioxyethylamphetamine PCP, phencyclidine LSD, lysergic acid diethylamide TEfC-COOH, ll-nor-A -tetrahydrocannabinol-9-carboxylic acid. 

Tetrahydrocannabinol (marijuana) is rapidly metabolized in the body to the tetrahydrocannibinol carboxylic acid or THC (Fig. 8.5). It is the THC metabolite that is commonly monitored in urine for drug analysis of marijuana. Because the THC structure contains both a phenolic hydroxyl group and a car-... 

Manno JE, Manno BR, Kemp PM, Alford DD, Abukhalaf IK, McWilliams ME, Hagaman FN, Fitzgerald MJ (2001) Temporal indication of marijuana use can be estimated from plasma and urine concentrations of delta-9-tetrahydrocannabinol, 1 l-hydroxy-dclla-9-lclra-hydrocannabinol, and 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid. J Anal Toxicol 25 538-549... 

Further cannabinoids are /d -tetrahydrocannabinolic acids A and B, which contain an additional carboxylic acid function at C-2 or C-4. [124] By smoking of cannabis these undergo decarboxylation and therefore raise the THC level (Fig. 5.66). 

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