Solid-phase extraction of 11-Nor-Δ9-tetrahydrocannabinol-9-carboxylic acid from urine drug-testing specimens with the Cerex PolyCrom-THC™ column
Solid-phase extraction of 11-Nor-Δ9-tetrahydrocannabinol-9-carboxylic acid from urine drug-testing specimens with the Cerex PolyCrom-THC™ column
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DOI:
10.1093/jat/24.4.245
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发表时间:
2000-05-01
影响因子:
2.5
通讯作者:
Urry, FM
中科院分区:
文献类型:
--
作者:
Crockett, DK;Nelson, G;Urry, FM
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-Δ9-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 withN-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-d9deuterated 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.