Application of two-dimensional gas chromatography with electron capture chemical ionization mass spectrometry to the detection of 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in hair.

Authors

Moore C, Rana S, Coulter C, et al. 

Institution

Immunalysis Corporation, 829 Towne Center Drive, Pomona, California 91767, USA. cmoore@immunalysis.com

Source

J Anal Toxicol 2006 Apr; 30(3) :171-7.

Abstract

The proposed federal regulations for the detection in hair of 11-nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), a metabolite of marijuana, require a confirmatory detection level of 0.05 pg/mg. At present, the only way to achieve this on a routine basis has been with the use gas chromatography with tandem mass spectrometry (GC-MS-MS) technology. Tandem MS is an expensive approach and dissuades laboratories from attempting to enter the hair-testing market. A procedure for the determination of THC-COOH in hair using two-dimensional gas chromatography (GC x GC) coupled to mass spectrometry (GC-GC-MS) is described for the first time. The method makes use of several small improvements in the extraction, GC, and MS procedures to allow the required sensitivity to be achieved. The results of this approach demonstrate detection of THC-COOH in hair at a concentration level of 0.05 pg/mg with both a target quantitation ion and a unique confirming qualifier ion, using a single-quadrupole mass selective detector. These two ions and the enhanced separation of the GC-GC provide a high degree of confidence in the determinations. The method has been successfully applied to the detection of THC-COOH in hair specimens from known marijuana users, and it reaches the levels currently proposed in the Federal Register.

Mesh

Gas Chromatography-Mass Spectrometry
Hair
Humans
Marijuana Smoking
Psychotropic Drugs
Reproducibility of Results
Substance Abuse Detection
Tetrahydrocannabinol

Language

eng

Pub Type(s)

Journal Article

PubMed ID

16803651