Enhancing high-resolution mass spectrometry performance for NPS analysis with improved sensitivity and characterization

Abstract

The aim of this presentation is to introduce the instrument features on the ZenoTOF 7600 system that provide qualitative flexibility combined with quantitative power for NPS detection and characterization. The presentation will demonstrate that these new technological advancements on the system can be leveraged to provide more confidence in the quantified amounts of drugs and metabolites detected in discarded authentic case samples which is critical when determining the cause of death following an accidental overdose. Drugs and metabolites were extracted from human whole blood using a liquid-liquid extraction (LLE) procedure. HPLC separation was performed on an ExionLC system using a Phenomenex Kinetex C18 column Mobile phases were ammonium formate and formic acid in methanol and acetonitrile. The flow rate was 0.4 mL/min with a total LC runtime of 15.5 minutes. The injection volume was 10 μL. MS and MS/MS data were collected for each sample using Zeno IDA for optimal sensitivity on the ZenoTOF 7600 system. Fragmentation was performed using both collision-induce dissociation (CID) and electron-activated dissociation (EAD) to compare the generated fragment ions. Data acquisition consisted of a TOF MS scan to collect accurate mass precursor ions from 100 to 700 Da, followed by a TOF MS/MS full scan ranging from 25 to 700 Da to ensure all fragments were captured for identification using a maximum of 16 candidate ions. Data was acquired using SCIEX OS software 2.1. The use of a hybrid collision cell (which offers an alternative fragmentation capabilities) in combination with the Zeno trap technology (which improves MS/MS duty cycle) was leveraged for the characterization of structurally related isomeric species present at low levels in discarded postmortem case samples. The depth of information extracted from the unique fragmentation capabilities of electron-activated dissociation (EAD) enabled differentiation of structurally related isomeric species that were not previously discernable using convention collision-induced dissociation (CID). In addition, the improved MS/MS sensitivity resulted in confident identification of potent novel synthetic opioids and metabolites at concentration levels that were not previously achievable. Overall, the use of the ZenoTOF 7600 system provided a means to characterize and monitor low-levels of ultra-potent NSO in poly-drug intake scenarios. These advancements are shown to support the case of combined opioid drug toxicity leading to death, which offers a clearer picture for help in determining the cause of death. A novel fragmentation technique combined with a highly-sensitive QTOF system for the screening and identification of low-level potent NSO and metabolites in discarded postmortem case samples is described. The depth of information extracted from EAD-based MS/MS spectra combined with the improved MS/MS sensitivity were leveraged for characterization of structurally related isomeric species present at low levels. The results demonstrate that the new technological advancements on the ZenoTOF 7600 provide high levels of confidence in the quantified amounts of drugs and metabolites detected in authentic case samples, which is critical when determining the cause of death following an accidental overdose.