High-resolution quadrupole time-of-flight mass spectrometry, a powerful technique to include in analytical scheme for the identification of drugs and chemicals in seizures: A case study

Abstract

A seizure containing 37 items was analyzed with laboratory identification scheme for drugs and chemicals in seized products applying accredited methods based on gas chromatography mass spectrometry (GC-MS) and liquid chromatography with photodiode-array detection (UPLC-PDA), a category A technique combined with category B and C techniques. No identification was obtained for 1 item [analogue of lysergic acid diethylamide (LSD)] and none detected or identified by GC-MS and/or UPLC-PDA for 8 items. All items were subsequently analyzed using ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-Tof) to investigate whether it is appropriate to include this technique in laboratory identification scheme for seized materials. The seizure consisted of individual packages containing blotter papers, capsules and powders, respectively. The powders were present in sealed alu-bags labeled ‘not for human consumption’ and Falcon® tubes, presumably purchased as ‘research chemical’. Methanolic solutions were analyzed. The GC-MS method was described elsewere (Coopman V. Toxicol Anal Clin 2018;30:75–79). Automated library search was performed against NIST, SWGDRUG and CAYMAN mass spectral library and mass spectra published in scientific literature were consulted. The UPLC-PDA analysis was performed with a Waters Acquity UPLC H-Class system. The compounds were separeted on an Acquity UPLC C18 column using gradient elution with a mobile phase consisting of 0.1% (v/v) formic acid aqueous solution and 0.1% (v/v) formic acid in acetonitrile, and photodiode-arra y detection. Automated library search was performed with Empower™ 3 software against in-house and Waters library. A Waters Acquity UPLC I-Class with Xevo G2-XS QTof was used, equipped with UNIFI® scientific information system and Forensic Toxicology Screening Application from Waters with data acquisition parameters for accurate mass analysis in positive and negative mode. Analogues of LSD (1P-LSD, ETH-LAD, AL-LAD) and a designer benzodiazepine (clonazolam) respectively, were identified in blotter paper by UPLC-PDA, GC-MS and confirmed by UPLC-Q-Tof. The unknown analogue of LSD was identified as ALD-52 by UPLC-Q-Tof. 4-fluoromethylphenidate (4F-MPH), N-ethyldeschloroketamine (O-PCE) and mirtagynine were identified in powder by UPLC-PDA, GC-MS and UPLC-Q-Tof. O-PCE was not present in the Forensic Toxicology Screening Application library and was therefore not automatically identified. Salicylic acid, caffeine, trazodone, pseudoephedrine, melatonin and ETH-LAD respectively, were identified in tablet or capsule with routine laboratory identification scheme and confirmed by UPLC-Q-Tof. In a capsule found to contain pseudoephedrine and unknown, a library hit was found for the designer drug N-methyl-2-aminoindane (NM-2AI) by UPLC-Q-Tof. Laboratory identification scheme for the identification of drugs and chemicals in seizures is based on GC-MS and UPLC-PDA, a category A technique and category B, C techniques (SWGDRUG recommendations). Not all drugs and chemicals were detected with both techniques. When identification is obtained with one or any of the applied techniques, a more extensive analysis is recommended. UPLC-Q-Tof is a sensitive and powerful technique, appropriate to include in laboratory identification scheme for seized materials when identification is obtained with one or any of the applied techniques or if the presence of low concentration, a NPS or designer drugs is suspected, allowing confirmation or identification.