title: Simultaneous identification and quantification of new psychoactive substances in blood by GC-APCI-QTOFMS coupled to nitrogen chemiluminescence detection without authentic reference standards.
abstract: A novel platform is introduced for simultaneous identification and quantification of new psychoactive substances (NPS) in blood matrix, without the necessity of using authentic reference standards. The instrumentation consisted of gas chromatography (GC) coupled to nitrogen chemiluminescence detection (NCD) and atmospheric pressure chemical ionization quadrupole time-of-flight mass spectrometry (APCI-QTOFMS). In this concept, the GC flow is divided in appropriate proportions between NCD for single-calibrant quantification, utilizing the detector's equimolar response to nitrogen, and QTOFMS for accurate mass-based identification. The principle was proven by analyzing five NPS, bupropion, desoxypipradrol (2-DPMP), mephedrone, methylone, and naphyrone, in sheep blood. The samples were spiked with the analytes post-extraction to avoid recovery considerations at this point. All the NPS studies produced a protonated molecule in APCI resulting in predictable fragmentation with high mass accuracy. The N-equimolarity of quantification by NCD was investigated by using external calibration with the secondary standard caffeine at five concentration levels between 0.17 and 1.7 mg/L in blood matrix as five replicates. The equimolarity was on average 98.7%, and the range of individual equimolarity determinations was 76.7-130.1%. The current analysis platform affords a promising approach to instant simultaneous qualitative and quantitative analysis of drugs in the absence of authentic reference standards, not only in forensic and clinical toxicology but also in other bioanalytical applications.
authors.affiliation: Department of Forensic Medicine, University of Helsinki, PO Box 40, 00014, Helsinki, Finland. ilkka.ojanpera@helsinki.fi.|Forensic Toxicology Unit, National Institute for Health and Welfare, PO Box 30, 00271, Helsinki, Finland. ilkka.ojanpera@helsinki.fi.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Ojanperä
authors.affiliation: Department of Forensic Medicine, University of Helsinki, PO Box 40, 00014, Helsinki, Finland.
authors.forename: Samuel
authors.initials: S
authors.lastname: Mesihää
authors.affiliation: Forensic Toxicology Unit, National Institute for Health and Welfare, PO Box 30, 00271, Helsinki, Finland.
authors.forename: Ilpo
authors.initials: I
authors.lastname: Rasanen
authors.affiliation: Forensic Toxicology Unit, National Institute for Health and Welfare, PO Box 30, 00271, Helsinki, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Pelander
authors.affiliation: Forensic Toxicology Unit, National Institute for Health and Welfare, PO Box 30, 00271, Helsinki, Finland.
authors.forename: Raimo A
authors.initials: RA
authors.lastname: Ketola
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D049449:Luminescence; D009584:Nitrogen / Q000737:chemistry*; D011619:Psychotropic Drugs / Q000097:blood*; D012015:Reference Standards
chemical_list: D011619:Psychotropic Drugs; D009584:Nitrogen
keywords: Accurate mass; Atmospheric pressure chemical ionization; Gas chromatography; New psychoactive substances; Nitrogen chemiluminescence detection; Time-of-flight mass spectrometry