title: Ultra-rapid targeted analysis of 40 drugs of abuse in oral fluid by LC-MS/MS using carbon-13 isotopes of methamphetamine and MDMA to reduce detector saturation.
abstract: The number of oral fluid samples collected by the road policing authority in Victoria, Australia, requiring confirmatory laboratory analysis for drugs proscribed under Victorian legislation (methamphetamine, MDMA and Δ9-tetrahydrocannabinol) has greatly increased in recent years, driving the need for improved analysis techniques to enable expedient results. The aim of this study was to develop an LC-MS/MS-based targeted oral fluid screening technique that covers a broad range of basic and neutral drugs of abuse that can satisfy increased caseload while monitoring other compounds of interest for epidemiological purposes. By combining small sample volume, simple extraction procedure, rapid LC-MS/MS analysis and automated data processing, 40 drugs of abuse including amphetamines, benzodiazepines, cocaine and major metabolites, opioids, cannabinoids and some designer stimulants were separated over 5 min (with an additional 0.5 min re-equilibration time). The analytes were detected using a Sciex® API 4500 Q-Trap LC-MS/MS system with positive ESI in MRM mode monitoring three transitions per analyte. The method was fully validated in accordance with international guidelines and also monitored carbon-13 isotopes of MDMA and MA to reduce detector saturation effects, allowing for confirmation of large concentrations of these compounds without the need for dilution or re-analysis. The described assay has been successfully used for analysis of oral fluid collected as part of law enforcement procedures at the roadside in Victoria, providing forensic results as well as epidemiological prevalence in the population tested. The fast and reliable detection of a broad range of drugs and subsequent automated data processing gives the opportunity for high throughput and fast turnaround times for forensic toxicology.
authors.affiliation: Victorian Institute of Forensic Medicine-Toxicology, 65 Kavanagh St, Southbank, Melbourne, Victoria, 3006, Australia. matthew.dirago@vifm.org.|Department of Forensic Medicine, Monash University, Melbourne, Victoria, 3006, Australia. matthew.dirago@vifm.org.
authors.forename: Matthew
authors.initials: M
authors.lastname: Di Rago
authors.affiliation: Victorian Institute of Forensic Medicine-Toxicology, 65 Kavanagh St, Southbank, Melbourne, Victoria, 3006, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Chu
authors.affiliation: Victorian Institute of Forensic Medicine-Toxicology, 65 Kavanagh St, Southbank, Melbourne, Victoria, 3006, Australia.|Department of Forensic Medicine, Monash University, Melbourne, Victoria, 3006, Australia.
authors.forename: Luke N
authors.initials: LN
authors.lastname: Rodda
authors.affiliation: Victorian Institute of Forensic Medicine-Toxicology, 65 Kavanagh St, Southbank, Melbourne, Victoria, 3006, Australia.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Jenkins
authors.affiliation: Victorian Institute of Forensic Medicine-Toxicology, 65 Kavanagh St, Southbank, Melbourne, Victoria, 3006, Australia.
authors.forename: Alex
authors.initials: A
authors.lastname: Kotsos
authors.affiliation: Victorian Institute of Forensic Medicine-Toxicology, 65 Kavanagh St, Southbank, Melbourne, Victoria, 3006, Australia.|Department of Forensic Medicine, Monash University, Melbourne, Victoria, 3006, Australia.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Gerostamoulos
mesh_terms: D002247:Carbon Isotopes; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D013287:Illicit Drugs / Q000032:analysis*; D008694:Methamphetamine / Q000032:analysis*; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000032:analysis*; D012463:Saliva / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D002247:Carbon Isotopes; D013287:Illicit Drugs; D008694:Methamphetamine; D018817:N-Methyl-3,4-methylenedioxyamphetamine
keywords: Carbon-13; Drugs and driving; Drugs of abuse; LC-MS/MS; Oral fluid