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Published:
Journal of Analytical Toxicology,
ISSN 0146-4760,
Volume 24,
Number 4, May/June 2000, pp.245-249
Solid-Phase
Extraction of 11-Nor-D9-Tetrahydrocannabinol-9-Carboxylic
Acid from Urine Drug-Testing Specimens with the Cerex PolyCrom-THC™ Column Confirmation
of drugs of abuse by gas chromatography–mass spectrometry (GC–MS)
is the most time-consuming process used by drug-testing laboratories. Cost effectiveness
and competitive turnaround times for testing results demand fast, efficient,
and reliable extraction methods. We applied the Cerex Polycrom-THC solid-phase
extraction (SPE) column to the extraction of 11-nor-D9-tetrahydrocannabinol
carboxylic acid (9-THCA) from urine. This column uses an anion exchange divinyl-benzene
copolymer, which requires no pH adjustment after hydrolysis of the THC-glucuronide
with base, as is necessary with many other SPE columns. With urine, no preconditioning
of the SPE column was necessary. After extraction, trimethylsilyation derivatization
was performed with N-methyl-N-(trimethylsilyl) trifluoroacetamide. This further
improved efficiency because no heated incubation was required. A method correlation
to an existing liquid–liquid extraction was performed. Analysis was on
a Finnigan Voyager GC–MS with a 2.5-min run time per injection. Using 9-THCA-d9
deuterated internal standard, the assay was linear from 2 to 2000 ng/mL. Total
precision at the 15-ng/mL cutoff concentration was 4.4%. The Cerex column was
also evaluated for interference using two common drug-test adulterants, Klear™
and Urine Luck™. Considerably less interference was observed when compared
to an existing liquid–liquid method.David
K. Crockett1, Gordon Nelson2, Philip Dimson3, and Francis M. Urry1,4
1ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, Utah
84108; 2General Medical Laboratories, Madison, Wisconsin 53715; 3SPEware, San
Pedro, California 90732; and 4Department of Pathology, University of Utah School
of Medicine, Salt Lake City, Utah 84112 Reproduction
of editorial content of this journal is prohibited without publisher’s
permission.
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