Journal Article

Simultaneous Analysis of 14 Benzodiazepines in Oral Fluid by Solid-Phase Extraction and LC-MS-MS

George Ngwa, Dean Fritch, Kristen Blum and Gregory Newland

in Journal of Analytical Toxicology

Volume 31, issue 7, pages 369-376
Published in print September 2007 | ISSN: 0146-4760
Published online September 2007 | e-ISSN: 1945-2403 | DOI:
Simultaneous Analysis of 14 Benzodiazepines in Oral Fluid by Solid-Phase Extraction and LC-MS-MS

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A simple and rapid procedure for the simultaneous screening of 14 benzodiazepines in oral fluid is presented. The procedure involves a solid-phase extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The target compounds include diazepam, oxazepam, temazepam, nordiazepam, lorazepam, chlordiazepoxide, alprazolam, α-hydroxyalprazolam, desalkylflurazepam, hydroxyethylflurazepam, clonazepam, 7-aminoclonazepam, flunitrazepam, and 7-aminoflunitrazepam. Oral fluid was obtained using a simple device that collects approximately 0.4 mL of oral fluid and dilutes it with 0.8 mL of preservative. The oral fluid sample preparation involves a solid-phase extraction on a Varian Bond Elut cartridge. Quantitation was performed by LC-MS-MS using nordiazepam-d5 as the internal standard. The extraction efficiency exceeded 83% for all compounds except for 7-aminoclonazepam, which had a recovery of 55%. The limits of quantitation ranged from 0.1 ng/mL to 1.0 ng/mL in the multiple reaction monitoring mode. This method was used to confirm 41 patients that screened positive using the OraSure Technologies Benzodiazepine Intercept® MICRO-PLATE Enzyme Immunoassay kit. All screened-positive patients were positive for at least one of the analyzed benzodiazepines, thus showing that this method is suitable for confirmation of the Intercept Benzodiazepine assay.

Journal Article.  0 words. 

Subjects: Medical Toxicology ; Toxicology (Non-medical)

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