Simultaneous analysis of 14 benzodiazepines in oral fluid by solid-phase extraction and LC-MS-MS.
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, alpha-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-d(5) 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.
Ngwa
George
G
Chemistry, Lehigh University, 6 E. Packer Ave., Seeley G. Mudd Building, Bethlehem, Pennsylvania 18015, USA.
Fritch
Dean
D
Blum
Kristen
K
Newland
Gregory
G
D001569:Benzodiazepines / Q000032:analysis* / Q000378:metabolism; D002853:Chromatography, Liquid / Q000379:methods; D006801:Humans; D006993:Hypnotics and Sedatives / Q000032:analysis* / Q000378:metabolism; D012015:Reference Standards; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry*; D052616:Solid Phase Extraction; D015813:Substance Abuse Detection / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods
D006993:Hypnotics and Sedatives; D001569:Benzodiazepines