Targeted and non‐targeted drug screening in whole blood by UHPLC‐TOF‐MS with data‐independent acquisition

Abstract

High-resolution mass spectrometry (HRMS) is widely used for the drug screening of biological samples in clinical and forensic laboratories. With the continuous addition of new psychoactive substances (NPS), keeping such methods updated is challenging. HRMS allows for combined targeted and non-targeted screening. First, peaks are identified by software algorithms, and identifications are based on reference standard data. Attempts are made to identify the remaining unknown peaks with in silico and literature data. However, several thousand peaks remain where most are unidentifiable or uninteresting in drug screening. The aims of the study were to apply a combined targeted and non-targeted screening approach to authentic driving-under-the-influence-of-drugs (DUID) samples (n = 44) and further validate the approach using whole-blood samples spiked with 11 low-dose synthetic benzodiazepine analogues (SBAs). Analytical data were acquired using ultra-high-performance liquid chromatography coupled with a time-of-flight mass spectrometer (UHPLC-TOF-MS) with data-independent acquisition (DIA). We present a combined targeted and non-targeted screening, where peak deconvolution and filtering reduced the number of peaks to inspect by three orders of magnitude, down to four peaks per DUID sample. The screening allowed for tentative identification of metabolites and drugs not included in the initial screening; 3 drugs and 14 metabolites were tentatively identified in the authentic DUID samples. Running targeted-screening true-positive identifications through the filters retained 73% of identifications. In the non-targeted screening, nine of the spiked SBAs were identified in the concentration range of 0.005-0.1 mg/kg, of which three were tentatively identified at concentrations below those reported in the literature. Copyright © 2016 John Wiley & Sons, Ltd.

How deaths can help clinicians and policy‐makers understand the risks of novel psychoactive substances

“…Whilst liquid chromatography‐mass spectrometry (LC‐MS/MS) is suitable for the detection of fentanyl, the use of thermal desorption direct analysis in real‐time mass spectrometry (TD‐DART‐MS) and ion mobility spectrometry (IMS) are required for the rapid and sensitive (nanogram to picogram) detection of its analogues such as acetyl fentanyl, carfentanil, furanyl fentanyl and isobutyryl fentanyl . Special facilities are also needed to use computational software tools (in vitro) in approaches for predicting molecular structures in forensic cases of suspected toxicity but where targeted analysis has not identified a drug . There is variability in the availability of such resources across UK forensic providers.…”

Retrospective analysis for valproate screening targets with liquid chromatography–high resolution mass spectrometry with positive electrospray ionization: An omics‐based approach

“…10 Protein precipitation was performed on a Tecan Freedom EVO 200 robotic platform (Tecan Group Ltd, Männedorf, Switzerland). 10 Protein precipitation was performed on a Tecan Freedom EVO 200 robotic platform (Tecan Group Ltd, Männedorf, Switzerland).…”

“…10 Structures were obtained from literature on VPA metabolism, [27][28][29] the Human Metabolome Database, 30 DrugBank, 31 and PubChem (www.pubchem.ncbi.nlm.nih.gov). Tentative identifications were performed by molecular formula elucidation and in-silico fragment ion matching in the UNIFI software, following a previously described in-silico assisted identification workflow.…”

“…[6][7][8][9][10] Another type of data analysis is metabolomics, where multivariate data analysis is used to elucidate differences between sample groups, i.e., positive versus negative controls. 1-5 Untargeted data acquisition makes it possible to (re)investigate data with suspect screening and non-target analysis.…”

Application of a screening method for fentanyl and its analogues using UHPLC‐QTOF‐MS with data‐independent acquisition (DIA) in MSE mode and retrospective analysis of authentic forensic blood samples

“…Sample preparation was performed using a fully automated protein precipitation according to a previously published method . Seven hundred μL acetonitrile was added to 0.100 g whole blood in a 96‐well plate, shaking was performed and then centrifugation was done at 1000 g for 10 minutes.…”