title: Validation of LC-TOF-MS screening for drugs, metabolites, and collateral compounds in forensic toxicology specimens.
abstract: Liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) analysis provides an expansive technique for identifying many known and unknown analytes. This study developed a screening method that utilizes automated solid-phase extraction to purify a wide array of analytes involving stimulants, benzodiazepines, opiates, muscle relaxants, hypnotics, antihistamines, antidepressants and newer synthetic "Spice/K2" cannabinoids and cathinone "bath salt" designer drugs. The extract was applied to LC-TOF-MS analysis, implementing a 13 min chromatography gradient with mobile phases of ammonium formate and methanol using positive mode electrospray. Several common drugs and metabolites can share the same mass and chemical formula among unrelated compounds, but they are structurally different. In this method, the LC-TOF-MS was able to resolve many isobaric compounds by accurate mass correlation within 15 ppm mass units and a narrow retention time interval of less than 10 s of separation. Drug recovery yields varied among spiked compounds, but resulted in overall robust area counts to deliver an average match score of 86 when compared to the retention time and mass of authentic standards. In summary, this method represents a rapid, enhanced screen for blood and urine specimens in postmortem, driving under the influence, and drug facilitated sexual assault forensic toxicology casework.
authors.affiliation: Harris County Institute of Forensic Sciences, Toxicology Laboratory, Houston, Texas 77054, USA.
authors.forename: Fessessework
authors.initials: F
authors.lastname: Guale
authors.forename: Shahriar
authors.initials: S
authors.lastname: Shahreza
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Walterscheid
authors.forename: Hsin-Hung
authors.initials: HH
authors.lastname: Chen
authors.forename: Crystal
authors.initials: C
authors.lastname: Arndt
authors.forename: Anna T
authors.initials: AT
authors.lastname: Kelly
authors.forename: Ashraf
authors.initials: A
authors.lastname: Mozayani
mesh_terms: D000662:Amphetamines / Q000097:blood; D000818:Animals; D000928:Antidepressive Agents / Q000097:blood; D001569:Benzodiazepines / Q000097:blood; D002186:Cannabinoids / Q000097:blood; D002853:Chromatography, Liquid / Q000379:methods*; D003042:Cocaine / Q000097:blood; D053593:Forensic Toxicology / Q000379:methods*; D005561:Formates / Q000378:metabolism; D006633:Histamine Antagonists / Q000097:blood; D006993:Hypnotics and Sedatives / Q000097:blood; D013058:Mass Spectrometry / Q000379:methods*; D000432:Methanol / Q000378:metabolism; D009294:Narcotics / Q000097:blood; D012756:Sheep; D052616:Solid Phase Extraction; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D000662:Amphetamines; D000928:Antidepressive Agents; D002186:Cannabinoids; D005561:Formates; D006633:Histamine Antagonists; D006993:Hypnotics and Sedatives; D009294:Narcotics; C030544:formic acid; D001569:Benzodiazepines; D003042:Cocaine; D000432:Methanol