title: High-Resolution Mass Spectrometry for Untargeted Drug Screening.
abstract: While gas chromatography-mass spectrometry (GC/MS) continues to be the forensic standard for toxicology, liquid chromatography coupled to tandem MS offers significant operational advantages for targeted confirmatory analysis. LC-high-resolution (HR)-MS has recently been available that offers advantages for untargeted analysis. HR-MS analyzers include the Orbitrap and time-of-flight MS. These instruments are capable of detecting 1 ppm mass resolution. Following soft ionization, this enables the assignment of exact molecular formula, limiting the number of candidate compounds. With this technique, presumptive identification of unknowns can be conducted without the need to match MS library spectra or comparison against known standards. For clinical toxicology, this can greatly expand on the number of drugs and metabolites that can be detected and reported on a presumptive basis. Definitive assignments of the compound's identity can be retrospectively determined with acquisition of the appropriate reference standard.
authors.affiliation: Department of Laboratory Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA, USA. wualan@labmed2.ucsf.edu.
authors.forename: Alan H B
authors.initials: AH
authors.lastname: Wu
authors.affiliation: Department of Laboratory Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Colby
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D053593:Forensic Toxicology / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D004364:Pharmaceutical Preparations / Q000097:blood* / Q000652:urine*; D015813:Substance Abuse Detection / Q000379:methods
chemical_list: D004364:Pharmaceutical Preparations
keywords: Exact molecular formula; High-resolution mass spectrometry; Orbitrap; Time-of-flight mass spectrometry; Untargeted mass screening