| |
Published:
Journal of Analytical Toxicology,
ISSN 0146-4760,
Volume 30, Issue 3, April 2006,
pp. 171-177
Application of Two-Dimensional Gas Chromatography with
Electron Capture Chemical Ionization Mass Spectrometry to the Detection of 11-nor-D9-Tetrahydrocannabinol-9-carboxylic
Acid (THC-COOH) in Hair
Christine Moore[1], Sumandeep Rana[1], Cynthia Coulter[1],
Fred Feyerherm[2], and Harry Prest[2]
[1]Immunalysis Corporation, 829 Towne Center Drive, Pomona, California 91767
and
[2]Agilent Technologies Inc., 395 Page Mill Road, Palo Alto, California 94306
The proposed federal regulations for the detection in hair of
11-nor-D9-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 ¥ 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.
Reproduction
of editorial content of this journal is prohibited without publisher’s
permission.
This
article is available in its entirety by fax for $4.00 per
page.
Visa or MasterCard accepted. To order electronically click here
or call: 847-647-2900 ext. 1323
or fax request to: 847-647-1155.
Please indicate JAT
volume and issue along with page numbers. |
|
Home | Subscribe
| Current Issue | Back Issues
| Search | Advertise | Other Publications
| |
